Signal processing apparatus and method for reducing the effects of interference and noise in wireless communication systems

• US 6,127,973 A
• Filed: 04/18/1997
• Issued: 10/03/2000
• Est. Priority Date: 04/18/1996
• Status: Expired due to Term

• Current Assignee: Industry-University Cooperation Foundation Hanyang University
• Original Assignee: Korea Telecom Freetel Company Limited
• Inventors: Choi, Seung Won, Yun, Dong Un
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US08/844,255
• Time in Patent Office: 1,264 Days
• Field of Search: 342/378, 342/383, 342/384, 342/457
• US Class Current: 342/378
• CPC Class Codes: H01Q 3/2611 Means for null steering; Adaptive interference nulling

Abstract

A signal processing apparatus for minimizing interference and for reducing effects of noise by controlling beam patterns of a telecommunication system having an array antenna, comprising: a means for computing a residue vector, by using a signal vector provided from said array antenna at each snapshot, a final array output signal of said telecommunication system at the last previous snapshot and a value of a gain vector of the present snapshot, and for outputting said residue vector; a means for synthesizing a scalar value, which is needed to generate a search direction vector, from said residue vector; a means for producing said search direction vector, by using said residue vector and said scalar value; a means for producing an adaptive gain, by using said signal vector, said search direction vector, said final array output signal of said telecommunication system at the last previous snapshot and the value of said gain vector of the present snapshot; and a means for updating said gain vector, by using said search direction vector and said adaptive gain at the present snapshot.

Claims

1. A signal processing apparatus for minimizing interference and for reducing effects of noise by controlling beam patterns of a telecommunication system having an array antenna, comprising:

a means for computing a residue vector (r), by using a signal vector (x(t)) provided from said array antenna at each snapshot, a final array output signal (y) of said telecommunication system at the last previous snapshot and a value of a gain vector (w) of the present snapshot, and for outputting said residue vector (r);

a means for synthesizing a scalar value (β

), which is needed to generate a search direction vector (υ

), from said residue vector (r);

a means for producing said search direction vector (υ

), by using said residue vector (r) and said scalar value (β

);

a means for producing an adaptive gain (ρ

), by using said signal vector (x(t)), said search direction vector (υ

), said final array output signal (y) of said telecommunication system at the last previous snapshot and the value of said gain vector (w) of the present snapshot; and

a means for updating said gain vector (w), by using said search direction vector (υ

) and said adaptive gain (ρ

) at the present snapshot.

2. The signal processing apparatus according to claim 1, wherein said gain vector (w) is determined by a value of an eigenvector corresponding to the maximum eigenvalue of an autocorrelation matrix of the signals induced at each antenna element of said array antenna.

3. The signal processing apparatus according to claim 2, wherein said gain vector (w) is determined by multiplying a predetermined constant on each element of said eigenvector, corresponding to said maximum eigenvalue of said autocorrelation matrix, in order to modify said gain vector without changing beam-pattern characteristics of said eigenvector of said maximum eigenvalue.

4. The signal processing apparatus, according to claim 2, wherein said gain vector (w) is determined by normalizing said eigenvector, corresponding to said maximum eigenvalue of said autocorrelation matrix, such that a magnitude of the normalized eigenvector becomes 1 and a beam-pattern characteristics of said eigenvector of said maximum eigenvalue remains unchanged.

5. The signal processing apparatus according to claim 2, wherein said autocorrelation matrix is computed by adding a first term and a second term, as shown in the equation given below:

(in the equation, said first term is the autocorrelation matrix, at the last previous snapshot, multiplied by a forgetting factor of which the magnitude is between 0 and 1, and said second term is a signal matrix computed with said signal vector (x(t)) obtained from each antenna element of said array antenna at the present snapshot)

space="preserve" listing-type="equation">R.sub.x (J+1)=f·

R.sub.x (J)+x((J+1)T.sub.S)x.sup.H ((J+1)T.sub.S)

where R_x (J+1) and R_x (J) denote said autocorrelation matrix at the J+1_-- st and J_-- th snapshots, respectively, f is said forgetting factor of which the magnitude lies between 0 and 1, T_S is a snapshot period, and superscript H denotes a Hermitian operator.

6. The signal processing apparatus according to claim 2, wherein said eigenvector corresponding to said maximum eigenvalue is computed by the procedures of:

(a) determining said gain vector to synchronize the phase of each signal induced at every antenna element to the phase of said signal induced at said reference antenna element, during the first snapshot; and

(b) updating said gain vector of the last previous snapshot, in such a way that a Rayleigh quotient defined by said autocorrelation matrix and said gain vector is maximized at each snapshot, and a gain value to be multiplied to said signal induced at said reference antenna element at each snapshot is maintained to be a real quantity, during the second snapshot and on.

7. The signal processing apparatus according to claim 6, wherein said reference antenna element is determined by an antenna element of which the phase of said signal is the latest of all said antenna elements in said array antenna at the present snapshot.

8. The signal processing apparatus according to claim 6, wherein said reference antenna element is determined by said antenna element of which the physical distance from a signal source to be communicated with at the present snapshot is farthest compared to the other antenna elements in said array antenna.

9. The signal processing apparatus according to claim 1, wherein said means for computing said residue vector comprises:

a first multiplying means which computes the squared value of said final array output (y(t)) at the last previous snapshot;

a plurality of second multiplying means which compute the inner product of said final array output (y(t)) at the last previous snapshot to said signal vector coming from said receiving means;

a plurality of third multiplying means which multiply the output of said first multiplying means by each corresponding element of said gain vector; and

a plurality of subtracting means which subtract each output of said second multiplying means from each corresponding output of said second multiplying means.

10. The signal processing apparatus according to claim 1, wherein said adaptive gain synthesizing means comprises:

a plurality of first multiplying means which multiply each element of said search direction vector (υ

) by the complex conjugate of each corresponding element of said signal vector (x(t));

a first adding means which adds the outputs of all said first multiplying means;

a plurality of second multiplying means which compute the square of absolute values of all the elements of said search direction vector (υ

);

a second adding means which adds the outputs of all said second multiplying means;

a plurality of third multiplying means which multiply the complex conjugate of each element of said gain vector by each corresponding element of said search direction vector, in a order;

a third adding means which adds the outputs of all said third multiplying means;

a fourth multiplying means which computes the square of an output of said first adding means;

a fifth multiplying means which multiplies said final array output (y(t)) of the last previous snapshot by said output of said first adding means;

a sixth multiplying means which computes the square of the absolute value of said final array output (y(t)) of the last previous snapshot; and

an adaptive gain computing means that is connected to said first adding means, said second adding means, said fourth multiplying means, said fifth multiplying means and said sixth multiplying means.

11. The signal processing apparatus according to claim 10, wherein said adaptive gain computing means generates said adaptive gain (ρ

) in accordance with the equation given below;

##EQU21## where F=C·

Re[D]-B·

Re[E],

G=C-|y(t)|² E,

H=Re[B]-|y(t)|² ·

Re[D], and

Re[·

] denotes the real part of the complex valued number "·

"

with B being the output of said fourth multiplying means, which is the result of the multiplication of A (Said A being the output of said first adding means, which is the result of the inner product of said signal vector and said search direction vector) and said final array output, C being the output of said sixth multiplying means, which is the square of said A, D being the output of said second adding means, which is the result of the inner product of said gain vector and said search direction vector, and E being the output of said third adding means, which is the result of the inner product of said search direction vector and itself.

12. The signal processing apparatus according to claim 1, wherein said gain vector updating means comprises:

a plurality of multiplying means which multiply said adaptive gain by each element of said search direction vector at the present snapshot; and

a plurality of adding means that add said gain vector obtained during the last previous snapshot to each output of said plurality of said multiplying means.

13. The signal processing apparatus according to claim 12, wherein said gain vector updating means further comprises a plurality of dividing means for dividing each output of said plurality of said adding means with the square root of N multiplied with the value of the output of said adding means connected to said reference antenna element, where N denotes the number of antenna elements in said array antenna.

14. The signal processing apparatus according to claim 1, wherein said scalar synthesizing means comprises:

a plurality of multiplying means which compute the square of the absolute value of each element of said residue vector;

an adding means that adds the outputs of all said multiplying means;

a dividing means that divides the output of said adding means at the present snapshot with another output of said adding means at the last previous snapshot; and

a sign exchanging means which multiplies -1 by an output of said dividing means.

15. The signal processing apparatus according to claim 1, wherein said search direction vector synthesizing means comprises:

a plurality of multiplying means for multiplying said scalar quantity by each element of said search direction vector of the last previous snapshot; and

a plurality of adding means for producing said search direction vector of the present snapshot, by adding each element of said residue vector and the output of said corresponding multiplying means.

16. A signal processing apparatus for minimizing interference and for reducing effects of noise by controlling beam patterns of a telecommunication system having an array antenna, comprising:

an autocorrelation generating means that produces an autocorrelation matrix from a signal vector (x(t)) provided from said array antenna at each snapshot;

a maximum eigenvalue synthesizing means that estimates the maximum eigenvalue of said autocorrelation matrix at each snapshot;

a residue vector synthesizing means that produces a residue vector, by using said autocorrelation matrix generated at each snapshot, said maximum eigenvalue and a value of a gain vector of the present snapshot;

a scalar synthesizing means that produces a scalar value, which is needed to generate a search direction vector, from said residue vector;

a search direction vector synthesizing means that produces said search direction vector, by using said residue vector and said scalar value;

an adaptive gain synthesizing means that produces an adaptive gain, by using said autocorrelation matrix, said search direction vector (υ

), said maximum eigenvalue at the present snapshot, and the value of said gain vector (w) at the present snapshot; and

a gain vector updating means that updates said gain vector by using said search direction vector and said adaptive gain at each present snapshot.

17. The signal processing apparatus according to claim 16, wherein said gain vector (w) is determined by the value of an eigenvector corresponding to the maximum eigenvalue of said autocorrelation matrix of the signals induced at each antenna element of said array antenna.

18. The signal processing apparatus according to claim 17, wherein said gain vector (w) is determined by multiplying a predetermined constant on each element of said eigenvector, corresponding to said maximum eigenvalue of said autocorrelation matrix, in order to modify said gain vector without changing the beam-pattern characteristics of said eigenvector of said maximum eigenvalue.

19. The signal processing apparatus, according to claim 17, wherein said gain vector (w) is determined by normalizing said eigenvector, corresponding to said maximum eigenvalue of said autocorrelation matrix, such that the magnitude of the normalized eigenvector becomes 1 and the beam-pattern characteristics of said eigenvector of said maximum eigenvalue remains unchanged.

20. The signal processing apparatus according to claim 17, wherein said autocorrelation matrix is computed by adding a first term and a second term as shown in the equation given below:

space="preserve" listing-type="equation">R.sub.x (J+1)=f·

R.sub.x (J)+x((J+1)T.sub.S)x.sup.H ((J+1)T.sub.S)

where

R_x (J+1) and R_x (J) denote the autocorrelation matrix at J+1_-- st and J_-- th snapshots, respectively;

f is the forgetting factor of which the magnitude lies in between 0 and 1;

T_S is a snapshot period;

superscript H denotes a Hermitian operator;

the first term in the equation is the autocorrelation matrix, at the last previous snapshot, multiplied by the forgetting factor of which the magnitude is between 0 and 1; and

the second term is the signal matrix computed with said signal vector (x(t)) obtained from each antenna element of said array antenna at the present snapshot.

21. The signal processing apparatus according to claim 17, wherein said eigenvector corresponding to said maximum eigenvalue is computed by the procedures of:

(a) determining said gain vector to synchronize the phase of each signal induced at every antenna element to the phase of said signal induced at said reference antenna element, during the first snapshot; and

(b) updating said gain vector of the last previous snapshot, in such a way that a Rayleigh quotient defined by said autocorrelation matrix and said gain vector is maximized at each snapshot, and a gain value to be multiplied to said signal induced at said reference antenna element at each snapshot is maintained to be a real quantity, during the second snapshot and on.

22. The signal processing apparatus according to claim 21, wherein said reference antenna element is determined by an antenna element of which the phase of said signal is the latest of all said antenna elements in said array antenna at the present snapshot.

23. The signal processing apparatus according to claim 21, wherein said reference antenna element is determined by the antenna element of which the physical distance from a signal source to be communicated with at the present snapshot is farthest compared to the other antenna elements in said array antenna.

24. The signal processing apparatus, according to claim 16, wherein said residue vector synthesizing means comprises:

a plurality of first multiplying means for multiplying, one by one, each element of each row of said autocorrelation matrix (R) by each corresponding element of said gain vector;

a plurality of first adding means, of which the number is as many as the number of rows of said autocorrelation matrix, for adding the outputs of all said first multiplying means;

a plurality of second multiplying means for multiplying every element of said gain vector by said maximum eigenvalue (λ

) that has been estimated presently; and

,

a plurality of second adding means for subtracting, one by one, each output of said first adding means from each corresponding output of said second multiplying means.

25. The signal processing apparatus, according to claim 16, wherein said maximum eigenvalue synthesizing means for producing said maximum eigenvalue, by utilizing said autocorrelation matrix generated from said autocorrelation matrix generating means at each snapshot and said gain vector at the present snapshot, comprises:

a plurality of first multiplying means for multiplying, one by one, each element of each row of said autocorrelation matrix by the corresponding element of said gain vector at the present snapshot;

a plurality of first adding means for adding the outputs of said first multiplying means of which each corresponding set is connected to a corresponding row of said autocorrelation matrix;

a plurality of second multiplying means for multiplying, one by one, each output of said first adding means by the complex conjugate of each corresponding element of said gain vector at the present snapshot; and

a second adding means for producing an estimated value for said maximum eigenvalue of said autocorrelation matrix of said present snapshot, by adding the outputs of all said second multiplying means respectively connected to each said corresponding row.

26. The signal processing apparatus according to claim 16, wherein said adaptive gain synthesizing means comprises:

a plurality of first multiplying means for multiplying, one by one, each element of each row of said autocorrelation matrix by the corresponding element of said search direction vector;

a plurality of first adding means, of which the number is as many as the number of rows of said autocorrelation matrix, for adding the results of said first multiplying means for each row;

a plurality of first multiplying means for multiplying each output of said first adding means by the complex conjugate of each corresponding element of said gain vector;

a second adding means for adding the outputs of all said second multiplying means;

a plurality of third multiplying means for multiplying each output of said first adding means by the complex conjugate of said corresponding element of said search direction vector;

a third adding means for adding the outputs of all said third multiplying means;

a plurality of fourth multiplying means for multiplying each element of said search direction vector by the complex conjugate of said corresponding element of said gain vector;

a fourth adding means for adding the outputs of all said fourth multiplying means;

a plurality of fifth multiplying means for multiplying each element of said search direction vector by the complex conjugate of each said element, one by one;

a fifth adding means for adding all the outputs of said fifth multiplying means; and

,

an adaptive gain computing means for computing an adaptive gain from the outputs of said second, third, fourth and fifth adding means.

27. The signal processing apparatus, according to claim 26, wherein said adaptive gain computing means generates said adaptive gain (ρ

) in accordance with the equation given below;

##EQU22## where E, F, and G are defined as E=B·

Re[C]-D·

Re[A],

F=B-λ

·

D,

G=Re[D]-λ

·

Re[C],

with A, B, C, and D being the output of said second adding means, said third adding means, said fourth adding means and said fifth adding means, respectively,

and λ

is said maximum eigenvalue, and Re[·

] denotes the real part of the complex quantity "·

".

28. A signal processing apparatus for minimizing interference and reducing effects of noises by controlling beam patterns of a telecommunication system having an array antenna, comprising:

a matrix operation approximation means for receiving a signal vector (x(t)) provided from said array antenna at each snapshot, and for generating a gamma vector (γ

) and a zeta vector (ζ

) by approximating, at each snapshot, a first and a second matrix-oriented operations including autocorrelation matrix operations with the corresponding vector operations;

a means for estimating the maximum eigenvalue of said autocorrelation matrix supplied from said matrix operation approximation means;

a means for generating a residue vector, by utilizing said gamma vector (γ

), said maximum eigenvalue and said gain vector of the present snapshot;

a means for generating a scalar quantity by utilizing said residue vector;

a means for generating a search direction vector, by utilizing said residue vector and said scalar quantity;

a means for generating an adaptive gain (ρ

) at each snapshot, by utilizing said zeta vector (ζ

), said search direction vector, said maximum eigenvalue and said gain vector at the present snapshot; and

a means for updating said gain vector by utilizing said search direction vector and said adaptive gain at each snapshot.

29. The signal processing apparatus according to claim 28, wherein said gain vector is determined by the eigenvector corresponding to the maximum eigenvalue of said autocorrelation matrix that is obtained from the signals induced at each antenna element of said array antenna.

30. The signal processing apparatus according to claim 29, wherein said gain vector is determined by multiplying a predetermined constant on each element of said eigenvector, corresponding to the maximum eigenvalue of said autocorrelation matrix, in order to modify said gain vector without changing the beam-pattern characteristics of said eigenvector of said maximum eigenvalue.

31. The signal processing apparatus according to claim 29, wherein said gain vector is determined by normalizing said eigenvector, corresponding to the maximum eigenvalue of said autocorrelation matrix, such that the magnitude of the normalized eigenvector becomes 1 and the beam-pattern characteristics of said eigenvector of the maximum eigenvalue remains unchanged.

32. The signal processing apparatus according to claim 29, wherein said autocorrelation matrix is computed by adding a first term and a second term, as shown in the equation given below:

(in the equation, said first term is the autocorrelation matrix, at the last previous snapshot, multiplied by a forgetting factor of which the magnitude is between 0 and 1, and said second term is a signal matrix computed with said signal vector (x(t)) obtained from each antenna element of said array antenna at the present snapshot)

space="preserve" listing-type="equation">R.sub.x (J+1)=f·

R.sub.x (J)+x((J+1)T.sub.S)x.sup.H ((J+1)T.sub.S)

where R_x (J+1) and R_x (J) denote said autocorrelation matrix at the J+1_-- st and J_-- th snapshots, respectively, f is said forgetting factor of which the magnitude lies between 0 and 1, T_S is a snapshot period, and superscript H denotes a Hermitian operator.

33. The signal processing apparatus according to claim 29, wherein said eigenvector corresponding to said maximum eigenvalue is computed by the procedures of:

(a) determining said gain vector to synchronize the phase of each signal induced at every antenna element to the phase of said signal induced at said reference antenna element, during the first snapshot; and

(b) updating said gain vector of the last previous snapshot, in such a way that a Rayleigh quotient defined by said autocorrelation matrix and said gain vector is maximized at each snapshot, and a gain value to be multiplied to said signal induced at said reference antenna element at each snapshot is maintained to be a real quantity, during the second snapshot and on.

34. The signal processing apparatus according to claim 33, said reference antenna element is determined by an antenna element of which the phase of said signal is the latest of all said antenna elements in said array antenna at the present snapshot.

35. The signal processing apparatus according to claim 33, wherein said reference antenna element is determined by an antenna element of which the physical distance from a signal source to be communicated with at the present snapshot is farthest compared to the other antenna elements in said array antenna.

36. The signal processing apparatus according to claim 28, wherein said residue vector synthesizing means comprises:

a plurality of multiplying means for multiplying every element of said gain vector by said maximum eigenvalue (λ

) that has been estimated presently; and

a plurality of adding means for subtracting, one by one, each element of said search direction vector from each corresponding output of said multiplying means.

37. The signal processing apparatus according to claim 28, wherein said matrix operation approximation means comprises:

a plurality of first multiplying means for multiplying each element of said signal vector (x), which is supplied from the outside, by the complex conjugate of said final array output (y) of said telecommunication system, which is produced at the last previous snapshot;

a plurality of second multiplying means for multiplying each element of said gamma vector computed at the last previous snapshot by a forgetting factor (f);

a plurality of third multiplying means for multiplying each element of said zeta vector computed at the last previous snapshot by said forgetting factor (f);

a plurality of fourth multiplying means for multiplying the outputs of said third multiplying means by said adaptive gain (ρ

) generated from said adaptive gain synthesizing means;

a plurality of first adding means for adding the outputs of said fourth multiplying means to the outputs of said second multiplying means;

a plurality of second adding means for adding the outputs of said first adding means to the outputs of said first multiplying means;

a plurality of fifth multiplying means for multiplying the complex conjugate of each element of said signal vector (x), by each corresponding element of said search direction vector (v), which is generated from said search direction vector synthesizing means;

a third adding means for adding up all the outputs of said fifth multiplying means;

a plurality of sixth multiplying means for multiplying the outputs of said third adding means to each element of said signal vector (x);

a plurality of seventh multiplying means for multiplying the outputs of said third multiplying means by said scalar quantity (β

); and

a plurality of fourth adding means for adding the outputs of said seventh multiplying means to each corresponding output of said sixth multiplying means.

38. The signal processing apparatus according to claim 28, wherein said maximum eigenvalue synthesizing means comprises:

a plurality of multiplying means for multiplying, one by one, each element of said gamma vector by the complex conjugate of each element of said gain vector at the present snapshot; and

an adding means for adding up all the outputs of said multiplying means.

39. The signal processing apparatus according to claim 28, wherein said adaptive gain synthesizing means comprises:

a plurality of first multiplying means for multiplying, one by one, each element of said zeta vector, which is an output of said matrix operation approximation means, by the complex conjugate of each corresponding element of said gain vector;

a first adding means for adding up all the outputs of said first multiplying means;

a plurality of second multiplying means for multiplying, one by one, each element of said zeta vector by the complex conjugate of each corresponding element of said search direction vector;

a second adding means for adding up all the outputs of said second multiplying means;

a third plurality of multiplying means for multiplying each element of said search direction vector by the complex conjugate of each corresponding element of said gain vector;

a third adding means for adding up all the outputs of said third multiplying means;

a plurality of fourth multiplying means for multiplying each element of said search direction vector by the complex conjugate of each corresponding element of said search direction vector;

a fourth adding means for adding up all the outputs of said multiplying means; and

an adaptive gain computing means for said adaptive gain from the outputs of said first, second, third and fourth adding means.

40. The signal processing apparatus, according to claim 39, wherein said adaptive gain synthesizing means generates said adaptive gain (ρ

) in accordance with the equation given below;

##EQU23## where E, F, and G are defined as E=B·

Re[C]-D·

Re[A],

F=B-λ

·

D,

G=Re[D]-λ

·

Re[C],

with A, B, C, and D being the output of said first adding means, said second adding means, said third adding means and said fourth adding means, respectively,

and λ

is the maximum eigenvalue, and Re[·

] denotes the real part of the complex quantity "·

".

41. A signal processing apparatus for minimizing interference and reducing effects of noises by controlling beam patterns of a telecommunication system having an array antenna, comprising:

a residue vector synthesizing means for generating a residue vector, by utilizing received signals provided from said array antenna at each snapshot, a final array output signal of said telecommunication system of the last previous snapshot and a phase delay vector during the last previous snapshot, and for outputting said residue vector;

a scalar synthesizing means connected to an output of said residue vector synthesizing means, for synthesizing a scalar value from said residue vector;

a search direction vector synthesizing means respectively connected to another output of said residue vector synthesizing means and an output of said scalar synthesizing means, for producing a search direction vector by using said residue vector and said scalar value;

an adaptive gain synthesizing means for generating a value of adaptive gain, by utilizing said received signals provided from said antenna elements at the present snapshot, a final array output signal of said telecommunication system at the last previous snapshot, said search direction vector provided from said search direction vector synthesizing means at the present snapshot and said phase delay vector during the last previous snapshot, and for outputting the value of said adaptive gain; and

a means for updating said phase delay vector, by utilizing said search direction vector and said adaptive gain of the present snapshot.

42. The signal processing apparatus according to claim 41, wherein said phase delay vector, each element of which is to be appended to the phase of said signal induced at each corresponding antenna element, is determined by the phase term of each element of said eigenvector corresponding to said maximum eigenvalue of said autocorrelation matrix that is obtained from said signals induced at said each antenna element of said array antenna.

43. The signal processing apparatus according to claim 42, wherein said phase delay vector is determined by the phase term of each element of said vector which is generated by multiplying a predetermined constant by said eigenvector corresponding to said maximum eigenvalue of said autocorrelation matrix, in order to modify said phase delay vector without changing the beam-pattern characteristics of said eigenvector of said maximum eigenvalue.

44. The signal processing apparatus according to claim 42, wherein said phase delay vector is determined by the phase term of each element of the normalized eigenvector corresponding to said maximum eigenvalue of said autocorrelation matrix, such that the magnitude of the normalized eigenvector becomes 1 and the beam-pattern characteristics of said eigenvector of said maximum eigenvalue remains unchanged.

45. The signal processing apparatus according to claim 42, wherein said autocorrelation matrix is computed by adding a first term and a second term, as shown in the equation given below:

(in the equation, said first term is the autocorrelation matrix, at the last previous snapshot, multiplied by a forgetting factor of which the magnitude is between 0 and 1, and said second term is a signal matrix computed with said signal vector (x(t)) obtained from each antenna element of said array antenna at said present snapshot)

space="preserve" listing-type="equation">R.sub.x (J+1)=f·

R.sub.x (J)+x((J+1)T.sub.S)x.sup.H ((J+1)T.sub.S)

where R_x (J+1) and R_x (J) denote said autocorrelation matrix at the J+1_-- st and J_-- th snapshots, respectively, f is said forgetting factor of which the magnitude lies between 0 and 1, T_S is a snapshot period, and superscript H denotes a Hermitian operator.

46. The signal processing apparatus according to claim 42, wherein said eigenvector corresponding to said maximum eigenvalue is computed by the procedures of:

(a) determining said phase delay vector to synchronize the phase of each signal induced at every antenna element to the phase of said signal induced at said reference antenna element, during the first snapshot; and

(b) updating said phase delay vector of the last previous snapshot, in such a way that a Rayleigh quotient defined by said autocorrelation matrix is maximized at each snapshot, and a phase delay to be appended to said signal induced at said reference antenna element at each snapshot is maintained to be a real quantity, during a second snapshot and on.

47. The signal processing apparatus, according to claim 46, said reference antenna element is determined by an antenna element of which the phase of said signal is the latest of all said antenna elements in said array antenna at the present snapshot.

48. The signal processing apparatus according to claim 46, wherein said reference antenna element is determined by an antenna element of which the physical distance from a signal source to be communicated with at the present snapshot is farthest compared to the other antenna elements in said array antenna.

49. The signal processing apparatus according to claim 41, wherein said residue vector synthesizing means comprises:

a first multiplying means which computes the squared value of said final array output signal (y(t)) at the last previous snapshot, which is obtained by adding the results of delaying the phase of said signal induced at each antenna element by the amount of the value of each corresponding element of said phase delay vector at each snapshot;

a plurality of second multiplying means for multiplying each element of said signal vector (x(t)) obtained from the signal induced at each antenna element by said final array output signal (y(t)) at the last previous snapshot;

a plurality of phase delaying means for delaying the phase of the squared result of said first multiplying means by the amount of the value of each corresponding element of said phase delay vector; and

a plurality of adding means for subtracting each of outputs of said second multiplying means from the corresponding output of said phase delaying means.

50. The signal processing apparatus according to claim 41, wherein said scalar synthesizing means comprises:

a plurality of multiplying means for computing the square of the magnitude of each element of said residue vector at the present snapshot;

an adding means for adding up all the outputs of said multiplying means;

a dividing means that divides the output of said adding means at the present snapshot with the output of said adding means at the previous snapshot; and

a sign exchanging means which multiplies -1 to the output of said dividing means.

51. The signal processing apparatus according to claim 41, wherein said search direction vector synthesizing means comprises:

a plurality of adding means that receive the outputs of said residue vector synthesizing means, respectively, for producing said search direction vector; and

a plurality of multiplying means for producing the inputs of said adding means, respectively, by multiplying each said element of said search direction vector at the previous snapshot by said scalar quantity (β

).

52. The signal processing apparatus according to claim 41, wherein said adaptive gain synthesizing means comprises:

a plurality of first multiplying means for multiplying, one by one, each element of said signal vector (x(t)) by each corresponding element of said search direction vector;

a plurality of second multiplying means which compute the square of each element of said search direction vector (υ

);

a first adding means which adds up all the squares of the elements of said search direction vector;

a plurality of phase delaying means for delaying the phase of every element of said search direction vector by the amount determined by each corresponding element of said phase delay vector at the present snapshot, respectively;

a second adding means which adds the outputs of said phase delaying means;

a third adding means which adds the outputs of said first multiplying means;

a third multiplying means which computes the square of the output of said third adding means;

a fourth multiplying means which multiplies the output of said third adding means by the output (y(t)) of said telecommunication system;

a fifth multiplying means which computes the square of said output (y(t)) of said telecommunication system at the present snapshot; and

an adaptive gain computing means that is connected to said first and second adding means and said third, fourth and fifth multiplying means.

53. The signal processing apparatus according to claim 52, wherein said adaptive gain computing means generates said adaptive gain (ρ

) in accordance with the equation given below;

##EQU24## where F=C·

D-B·

E, G=C-y(t)² E, H=B-y(t)² ·

D,

with B being the output of said fourth multiplying means, which is the result of the multiplication of A (Said A being the output of said third adding means) and said array output, C being the output of said third multiplying means, which is the square of said A, D being the output of said second adding means, and E being the output of said first adding means.

54. The signal processing apparatus according to claim 41, wherein said phase delay vector updating means comprises:

a multiplying means for multiplying each element of said search direction vector by said adaptive gain (ρ

), which is generated from said adaptive gain synthesizing means;

a plurality of phase delaying means for delaying the phase of an oscillator output of which the frequency is the same as the carrier frequency of said received signal at each said antenna element by the amount determined by each corresponding element of the phase delay vector at the last previous snapshot;

a plurality of adding means for adding the outputs of said multiplying means and the outputs of said phase delaying means, respectively; and

a phase detecting means for generating the value of said phase delay vector at the present snapshot from the phase of each output of said adding means.

55. The signal processing apparatus according to claim 41, wherein said phase delaying means comprises:

a plurality of switching means each of which selects the smaller element after comparing the magnitude of the first element and the last element of said phase delay vector, which is generated from said phase detecting means at each snapshot; and

a plurality of adding means for subtracting each output of said switching means from each corresponding output of said phase detecting means, respectively.

56. A signal processing method for minimizing interference and reducing effects of noises by controlling beam patterns of a telecommunication system having an array antenna, comprising the steps of:

(a) synthesizing a residue vector by using a signal vector (x(t)) provided from said array antenna at each snapshot, a final array output signal (y) of said telecommunication system at the last previous snapshot and a value of a gain vector (w) of the present snapshot;

(b) synthesizing a scalar value, which is needed to generate a search direction vector, from said residue vector;

(c) producing a search direction vector by using said residue vector and said scalar value;

(d) producing an adaptive gain by using said signal vector (x(t)), said search direction vector (υ

), said final array output signal (y) of said telecommunication system at the last previous snapshot and the value of gain vector (w) of the present snapshot; and

(e) updating said gain vector by using said search direction vector and said adaptive gain at the present snapshot.

57. The signal processing method according to claim 56, wherein said gain vector (w) is determined by a value of an eigenvector corresponding to said maximum eigenvalue of a autocorrelation matrix of signals induced at each antenna element of said array antenna.

58. The signal processing method according to claim 57, wherein said gain vector (w) is determined by multiplying a predetermined constant on each element of said eigenvector, corresponding to said maximum eigenvalue of said autocorrelation matrix, in order to modify said gain vector without changing the beam-pattern characteristics of said eigenvector of said maximum eigenvalue.

59. The signal processing method according to claim 57, wherein said gain vector (w) is determined by normalizing said eigenvector, corresponding to said maximum eigenvalue of said autocorrelation matrix, such that a magnitude of the normalized eigenvector becomes 1 and the beam-pattern characteristics of said eigenvector of said maximum eigenvalue remains unchanged.

60. The signal processing method according to claim 57, wherein said autocorrelation matrix is computed by adding a first term and a second term, as shown in the equation given below:

(in the equation, said first term is the autocorrelation matrix, at the last previous snapshot, multiplied by a forgetting factor of which the magnitude is between 0 and 1, and said second term is a signal matrix computed with said signal vector (x(t)) obtained from each antenna element of said array antenna at the present snapshot)

space="preserve" listing-type="equation">R.sub.x (J+1)=f·

R.sub.x (J)+x((J+1)T.sub.S)x.sup.H ((J+1)T.sub.S)

where R_x (J+1) and R_x (J) denote said autocorrelation matrix at the J+1_-- st and J_-- th snapshots, respectively, f is said forgetting factor of which the magnitude lies between 0 and 1, T_S is a snapshot period, and superscript H denotes a Hermitian operator.

61. The signal processing method according to claim 57, wherein said eigenvector corresponding to said maximum eigenvalue is computed by the procedures of:

(a) determining said gain vector to synchronize the phase of each signal induced at every antenna element to the phase of said signal induced at said reference antenna element, during the first snapshot; and

(b) updating said gain vector of the last previous snapshot, in such a way that a Rayleigh quotient defined by said autocorrelation matrix and said gain vector is maximized at each snapshot, and a gain value to be multiplied to said signal induced at said reference antenna element at each snapshot is maintained to be a real quantity, during a second snapshot and on.

62. The signal processing method according to claim 56, wherein said step of synthesizing said residue vector includes:

a first substep for computing the square of said final array output signal (y(t)) of said telecommunication system at the last previous snapshot;

a second substep for computing the inner product of said final array output signal (y(t)) at the last previous snapshot to each element of said signal vector provided by said array antenna;

a third substep for multiplying the squared output obtained in said first substep by each element of said gain vector; and

a fourth substep for subtracting the results of said third substep from the results of said second substep, respectively.

63. The signal processing method according to claim 56, wherein said step of synthesizing said adaptive gain comprises:

a first substep for multiplying the complex conjugate of each element of said signal vector (x(t)) by the corresponding element of said search direction vector (υ

), respectively;

a second substep for adding up the results of said first substep;

a third substep for computing the square of the magnitude of each element of said search direction vector (υ

);

a fourth substep of adding the results of said third substep;

a fifth substep for multiplying the complex conjugate of each element of said gain vector by the corresponding element of said search direction vector;

a sixth substep for adding up the results of said fifth substep;

a seventh substep for computing the square of the result of said sixth substep;

an eighth substep for multiplying the result of said sixth substep by said final array output (y(t)) of said telecommunication system at the last previous snapshot;

a ninth substep for computing the square of the magnitude of said final array output (y(t)); and

a tenth substep for computing said adaptive gain by utilizing the results of said fourth, sixth, seventh, eighth and ninth substeps.

64. The signal processing method according to claim 63, wherein said tenth substep generates said adaptive gain in accordance with the equation given below:

##EQU25## where F=C·

Re[D]-B·

Re[E],

G=C-|y(t)|² E, H=Re[B]-|y(t)|² ·

Re[D], and

Re[·

] denotes the real part of the complex-valued quantity "·

"

with B being the result of the multiplication of A (Said A being the result of the inner product of said signal vector and said search direction vector) and said final array output, C being the square of said A, D being the result of the inner product of said gain vector and said search direction vector, and E being the result of the inner product of said search direction vector and itself.

65. The signal processing method according to claim 56, wherein said step of updating said gain vector includes:

a first substep for multiplying each element of said search direction vector at the present snapshot by said adaptive gain; and

a second substep for adding each element of gain vector at the last previous snapshot to the corresponding element of the results of said first substep.

66. The signal processing method according to claim 65, wherein said step of updating said gain vector further includes:

a third substep for dividing all the elements of the results of said second substep by the value of the first element of the results of said second substep multiplied by √

N, where N denotes the number of antenna elements of said array antenna system.

67. The signal processing method according to claim 56, wherein said step of synthesizing said scalar value includes:

a first substep for computing the square of the magnitude of each element of said residue vector;

a second substep for adding up all the results of said first substep;

a third substep for dividing the result of said second substep at the present snapshot with the result of said second substep at the last previous snapshot; and

a fourth substep for changing the sign of the result of said third substep.

68. The signal processing method according to claim 56, wherein said step of producing said search direction vector comprises:

a first substep of multiplying said scalar quantity by each element of said search direction vector of the last previous snapshot; and

a second substep of producing said search direction vector of the present snapshot, by adding each element of said residue vector and the output of said first substep.

69. A signal processing method for minimizing interference and reducing effects of noises by controlling beam patterns of a telecommunication system having an array antenna, comprising the steps of:

(a) generating an autocorrelation matrix from a signal vector (x(t)) provided from said array antenna at each snapshot;

(b) synthesizing a maximum eigenvalue of the autocorrelation matrix at each snapshot;

(c) synthesizing a residue vector from the autocorrelation matrix generated at each snapshot, the maximum eigenvalue, and a present value of a gain vector;

(d) synthesizing a scalar value, which is needed to generate a search direction vector, from said residue vector;

(e) synthesizing a search direction vector from said residue vector and said scalar value;

(f) synthesizing an adaptive gain from said autocorrelation matrix, said search direction vector (υ

), said maximum eigenvalue, and the present value of said gain vector (w); and

(g) updating said gain vector from said search direction vector and adaptive gain at each present snapshot.

70. The signal processing method according to claim 69, wherein said gain vector is determined by the eigenvector corresponding to the maximum eigenvalue of said autocorrelation matrix that is obtained from the signals induced at each antenna element of said array antenna.

71. The signal processing method according to claim 70, wherein said gain vector is determined by multiplying a predetermined constant on each element of said eigenvector, corresponding to said maximum eigenvalue of said autocorrelation matrix, in order to modify said gain vector without changing the beam-pattern characteristics of said eigenvector of said maximum eigenvalue.

72. The signal processing method according to claim 70, wherein said gain vector is determined by normalizing said eigenvector, corresponding to the maximum eigenvalue of said autocorrelation matrix, such that the magnitude of the normalized eigenvector becomes 1 and the beam-pattern characteristics of said eigenvector of said maximum eigenvalue remains unchanged.

73. The signal processing method according to claim 70, wherein said autocorrelation matrix is computed by adding a first term and a second term, as shown in the equation given below:

(in the equation, said first term is the autocorrelation matrix, at the last previous snapshot, multiplied by a forgetting factor of which the magnitude is between 0 and 1, and said second term is a signal matrix computed with said signal vector (x(t)) obtained from each antenna element of said array antenna at the present snapshot)

space="preserve" listing-type="equation">R.sub.x (J+1)=f·

R.sub.x (J)+x((J+1)T.sub.S)x.sup.H ((J+1)T.sub.S)

where R_x (J+1) and R_x (J) denote said autocorrelation matrix at the J+1_-- st and J_-- th snapshots, respectively, f is said forgetting factor of which the magnitude lies between 0 and 1, T_S is a snapshot period, and superscript H denotes a Hermitian operator.

74. The signal processing method according to claim 70, wherein said eigenvector corresponding to said maximum eigenvalue is computed by the procedures of:

(a) determining said gain vector to synchronize the phase of each signal induced at every antenna element to the phase of said signal induced at said reference antenna element, during the first snapshot; and

(b) updating said gain vector of the last previous snapshot, in such a way that a Rayleigh quotient defined by said autocorrelation matrix and said gain vector is maximized at each snapshot, and a gain value to be multiplied to said signal induced at said reference antenna element at each snapshot is maintained to be a real quantity, during a second snapshot and on.

75. The signal processing method according to claim 69, wherein said step of generating said residue vector includes:

a first substep for multiplying each element of each row of said autocorrelation matrix (R) by the corresponding element of said gain vector;

a second substep for adding up all the results of said first substep;

a third substep for multiplying each element of said gain vector by the maximum eigenvalue estimated presently; and

a fourth substep for subtracting, one by one, the result of said second substep from each element of the results of said third substep.

76. The signal processing method according to claim 69, wherein said step of estimating the maximum eigenvalue, by utilizing said autocorrelation matrix generated from said step of generating the autocorrelation matrix at each snapshot and said gain vector at the present snapshot, includes:

a first substep for multiplying, one by one, each element of each row of said autocorrelation matrix by each corresponding element of said gain vector at the present snapshot;

a second substep for adding up all the outputs of said first substep each set of which are connected to each corresponding row;

a third substep for multiplying, one by one, each element of the results of said second substep by the complex conjugate of each corresponding element of said gain vector at the present snapshot; and

a fourth substep for producing the estimated value for said maximum eigenvalue of said autocorrelation matrix of the present snapshot by adding the results of said third substep.

77. The signal processing method according to claim 69, wherein said step of synthesizing said adaptive gain includes:

a first substep for multiplying each element of each row of said autocorrelation matrix by each corresponding element of said search direction vector;

a second substep for adding up all the results of said first substep;

a third substep for multiplying the complex conjugate of each element of said gain vector by the result of said second substep;

a fourth substep for adding up all the results of said third substep;

a fifth substep for multiplying the complex conjugate of each element of said search direction vector by the result of said second substep;

a sixth substep for adding up all the results of said fifth substep;

a seventh substep for multiplying each element of said search direction vector by the complex conjugate of each corresponding element of said gain vector;

an eighth substep for adding up all the results of said seventh substep;

a ninth substep for multiplying each element of said search direction vector by the complex conjugate of each said element itself;

a tenth substep for adding up all the results of said ninth substep; and

an eleventh substep for computing said adaptive gain by utilizing the results of said fourth, sixth, eighth and tenth substeps.

78. The signal processing method according to claim 77, wherein said eleventh substep generates said adaptive gain in accordance with the equation given below:

##EQU26## where E=B·

Re[C]-D·

Re[A],

F=B-λ

D,

G=Re[CD]-λ

·

Re[C],

λ

denotes the maximum eigenvalue, and

Re[·

] denotes the real part of the complex-valued quantity "·

"

with A being the result of said fourth substep, B being the result of said sixth substep, C being the result of said eighth substep, and D being the result of said tenth substep.

79. A signal processing method for minimizing interference and reducing effects of noises by controlling beam patterns of a telecommunication system having an array antenna, comprising the steps of:

(a) generating a gamma vector (γ

) and a zeta vector (ζ

) by approximating an autocorrelation matrix operations with a corresponding vector operations by utilizing a signal vector provided from said array antenna at each snapshot;

(b) estimating a maximum eigenvalue of autocorrelation matrix by utilizing a gain vector at present snapshot and said gamma vector (γ

);

(c) generating a residue vector by utilizing said gamma vector (γ

), said maximum eigenvalue of autocorrelation matrix, and said gain vector of the present snapshot;

(d) generating a scalar quantity by utilizing said residue vector;

(e) generating a search direction vector by utilizing said residue vector and said scalar quantity;

(f) generating an adaptive gain at each snapshot by utilizing said zeta vector (ζ

), said search direction vector, said maximum eigenvalue of autocorrelation matrix, and said gain vector at the present snapshot; and

(g) updating said gain vector by utilizing said search direction vector and said adaptive gain at each snapshot.

80. The signal processing method, according to claim 79, wherein said gain vector is determined by the eigenvector corresponding to the maximum eigenvalue of said autocorrelation matrix that is obtained from the signals induced at each antenna element of said array antenna.

81. The signal processing method according to claim 80, wherein said gain vector is determined by multiplying a predetermined constant on each element of said eigenvector, corresponding to said maximum eigenvalue of said autocorrelation matrix, in order to modify said gain vector without changing the beam-pattern characteristics of said eigenvector of said maximum eigenvalue.

82. The signal processing method according to claim 80, wherein said gain vector is determined by normalizing said eigenvector, corresponding to the maximum eigenvalue of said autocorrelation matrix, such that the magnitude of the normalized eigenvector becomes 1 and the beam-pattern characteristics of said eigenvector of said maximum eigenvalue remains unchanged.

83. The signal processing method according to claim 80, wherein said autocorrelation matrix is computed by adding a first term and a second term, as shown in the equation given below:

(in the equation, said first term is the autocorrelation matrix, at the last previous snapshot, multiplied by a forgetting factor of which the magnitude is between 0 and 1, and said second term is a signal matrix computed with said signal vector (x(t)) obtained from each antenna element of said array antenna at the present snapshot)

space="preserve" listing-type="equation">R.sub.x (J+1)=f·

R.sub.x (J)+x((J+1)T.sub.S)x.sup.H ((J+1)T.sub.S)

where R_x (J+1) and R_x (J) denote said autocorrelation matrix at the J+1_-- st and J_-- th snapshots, respectively, f is said forgetting factor of which the magnitude lies between 0 and 1, T_S is a snapshot period, and superscript H denotes a Hermitian operator.

84. The signal processing method according to claim 80, wherein said eigenvector corresponding to said maximum eigenvalue is computed by the procedures of:

(a) determining said gain vector to synchronize the phase of each signal induced at every antenna element to the phase of said signal induced at said reference antenna element, during the first snapshot; and

(b) updating said gain vector of the last previous snapshot, in such a way that a Rayleigh quotient defined by said autocorrelation matrix and said gain vector is maximized at each snapshot, and a gain value to be multiplied to said signal induced at said reference antenna element at each snapshot is maintained to be a real quantity, during a second snapshot and on.

85. The signal processing method according to claim 79, wherein said step of synthesizing said residue vector includes:

a first substep for multiplying every element of said gain vector by said maximum eigenvalue (λ

) that has been estimated at the present snapshot; and

,

a second substep for subtracting, one by one, each element of said search direction vector from each corresponding output of said first substep.

86. The signal processing method according to claim 79, wherein said step of generating said gamma vector (γ

) and said zeta vector (ζ

) comprises;

a first substep for multiplying each element of said signal vector (x), which is supplied from the outside, by the complex conjugate of said final array output (y(t)) of said telecommunication system, which is produced at the last previous snapshot;

a second substep for multiplying each element of said gamma vector computed at the last previous snapshot by said forgetting factor (f);

a third substep for multiplying each element of said zeta vector computed at the last previous snapshot by said forgetting factor (f);

a fourth substep for multiplying the outputs of said third substep by said adaptive gain (ρ

);

a fifth substep for adding the outputs of said fourth substep and said second substep;

a sixth substep for adding the outputs of said first substep and said fifth substep;

a seventh substep for multiplying the complex conjugate of each element of said signal vector (x), by each corresponding element of said search direction vector (v);

an eighth substep for adding up all the outputs of said seventh substep;

a ninth substep for multiplying the output of said eight substep by each element of said signal vector (x);

a tenth substep for multiplying the output of said fourth by said scalar quantity (β

); and

an eleventh substep for adding the outputs of said ninth substep and said tenth substep.

87. The signal processing method according to claim 79, wherein said step of synthesizing said maximum eigenvalue, by utilizing said gamma vector generated from said step of approximating the matrix operation at each snapshot and said gain vector at the present snapshot, includes:

a first substep for multiplying, one by one, each element of said gamma vector by the complex conjugate of each element of said gain vector at the present snapshot; and

a second substep for adding up all the outputs of said first substep.

88. The signal processing method according to claim 79, wherein said step of synthesizing said adaptive gain includes:

a first substep for multiplying, one by one, each element of said zeta vector, which is one output of said step of approximating the matrix operation, by the complex conjugate of each corresponding element of said gain vector;

a second substep for adding up all the outputs of said first substep;

a third substep for multiplying, one by one, each element of said zeta vector by the complex conjugate of each corresponding element of said search direction vector;

a fourth substep for adding up all the outputs of said third substep;

a fifth substep for multiplying each element of said search direction vector by the complex conjugate of each corresponding element of said gain vector;

a sixth substep for adding up all the outputs of said fifth substep;

a seventh substep for multiplying each element of said search direction vector by the complex conjugate of the each element;

an eighth substep for adding up all the outputs of said seventh substep; and

a ninth substep of computing said adaptive gain from the outputs of said second, fourth, sixth and eighth substep.

89. The signal processing method, according to claim 88, wherein said ninth substep generates said adaptive gain (ρ

) in accordance with the equation given below;

##EQU27## where E, F, and G are defined as E=B·

Re[C]-D·

Re[A],

F=B-λ

·

D,

G=Re[A]-λ

·

Re[C],

with A, B, C, and D being the output of said second substep, said fourth substep, said sixth substep and said eighth substep, respectively,

and λ

is the maximum eigenvalue, and Re[·

] denotes the real part of the complex quantity "·

".

90. A signal processing method for minimizing interference and reducing effects of noises by controlling beam patterns of a telecommunication system having an array antenna, comprising the steps of:

(a) synthesizing a residue vector, by utilizing received signals provided from said array antenna at each snapshot, a final array output signal of said telecommunication system at the last previous snapshot and a phase delay vector during the last previous snapshot;

(b) synthesizing a scalar value from said residue vector;

(c) synthesizing a search direction vector by using said residue vector and said scalar value;

(d) synthesizing a value of adaptive gain, by utilizing the received signals of present snapshot provided from the antenna elements, said final array output signal of said telecommunication system at the last previous snapshot, said search direction vector of the present snapshot and said phase delay vector during the last previous snapshot; and

(e) updating said phase delay vector by utilizing said search direction vector and said adaptive gain of the present snapshot.

91. The signal processing method according to claim 90, wherein said phase delay vector, each element of which is to be appended to the phase of said signal induced at the corresponding antenna element, is determined by the phase term of each element of said eigenvector corresponding to said maximum eigenvalue of said autocorrelation matrix that is obtained from said signals induced at each said antenna element of said array antenna.

92. The signal processing method according to claim 91, wherein said phase delay vector is determined by the phase term of each element of said vector which is generated by multiplying the predetermined constant by said eigenvector corresponding to said maximum eigenvalue of said autocorrelation matrix, in order to modify said phase delay vector without changing the beam-pattern characteristics of said eigenvector of said maximum eigenvalue.

93. The signal processing method according to claim 91, wherein said phase delay vector is determined by the phase term of each element of the normalized eigenvector corresponding to said maximum eigenvalue of said autocorrelation matrix, such that the magnitude of the normalized eigenvector becomes 1 and said beam-pattern characteristics of said eigenvector of said maximum eigenvalue remains unchanged.

94. The signal processing method according to claim 91, wherein said autocorrelation matrix is computed by adding a first term and a second term, as shown in the equation given below:

(in the equation, said first term is the autocorrelation matrix, at the last previous snapshot, multiplied by a forgetting factor of which the magnitude is between 0 and 1, and said second term is a signal matrix computed with said signal vector (x(t)) obtained from each antenna element of said array antenna at the present snapshot)

space="preserve" listing-type="equation">R.sub.x (J+1)=f·

R.sub.x (J)+x((J+1)T.sub.S)x.sup.H (J+1)T.sub.S)

where R_x (J+1) and R_x (J) denote said autocorrelation matrix at the J+1_-- st and J_-- th snapshots, respectively, f is said forgetting factor of which the magnitude lies between 0 and 1, T_S is a snapshot period, and superscript H denotes a Hermitian operator.

95. The signal processing method according to claim 91, wherein said eigenvector corresponding to said maximum eigenvalue is computed by the procedures of:

(a) determining said phase delay vector to synchronize the phase of each signal induced at every antenna element to the phase of said signal induced at said reference antenna element, during the first snapshot; and

(b) updating said phase delay vector of the last previous snapshot, in such a way that a Rayleigh quotient defined by said autocorrelation matrix is maximized at each snapshot, and a phase delay to be appended to said signal induced at said reference antenna element at each snapshot is maintained to be a real quantity, during a second snapshot and on.

96. The signal processing method according to claim 90, wherein said step of synthesizing said residue vector includes:

a first substep for computing the squared value of said final array output (y(t)) at the previous snapshot, which is obtained by adding the results of delaying the phase of the signal induced at each antenna element by the amount of the value of each corresponding element of said phase delay vector at each snapshot;

a second substep for multiplying each element of said signal vector (x(t)) obtained from the signal induced at said each antenna element by said final array output (y(t));

a third substep for delaying the phase of the squared result of said first substep by the amount of the value of each corresponding element of said phase delay vector; and

a fourth substep for subtracting each of outputs of said second substep from each corresponding output of said third substep.

97. The signal processing method according to claim 90, wherein said step of synthesizing said scalar includes:

a first substep for computing the square of the magnitude of each element of said residue vector at the present snapshot;

a second substep for adding up all the outputs of said first substep;

a third substep for dividing the output of said second substep at the present snapshot with the output of said second substep at the last previous snapshot; and

a fourth substep for changing the sign of the output of said third substep.

98. The signal processing method according to claim 90, wherein said step of synthesizing said search direction vector includes:

a first substep for producing each element of said search direction vector, by utilizing the the results of said step of synthesizing said residue vector; and

a second substep for producing the inputs of said first substep, by multiplying said each element of said search direction vector at the last previous snapshot by said scalar quantity (β

).

99. The signal processing method according to claim 90, wherein said step of synthesizing said adaptive gain includes:

a first substep for multiplying, one by one, each element of said signal vector (x(t)) by each corresponding element of said search direction vector;

a second substep for computing the square of each element of said search direction vector (υ

);

a third substep for adding the outputs of said second substep;

a fourth substep for delaying the phase of every element of said search direction vector by the amount determined by each corresponding element of said phase delay vector at the present snapshot, respectively;

a fifth substep for adding up all elements of the results of said fourth substep;

a sixth substep for adding up all the results of said first substep;

a seventh substep for computing the square of the result of said sixth substep;

an eighth substep for multiplying the final array output of said telecommunication system by the result of said sixth substep;

a ninth substep for computing the square of said final array output of said telecommunication system; and

a tenth substep for computing said adaptive gain by utilizing the results of said third, fifth, seventh, and ninth substeps.

100. The signal processing method according to claim 99, wherein said tenth substep generates said adaptive gain (ρ

) in accordance with the equation given below;

##EQU28## where F=C·

D-B·

E,

G=C-y(t)² E,

H=B-y(t)² ·

D,

with B being the output of eighth substep, C being the output of said seventh substep, and E being the output of said fifth substep.

101. The signal processing method according to claim 90, wherein said step of updating said phase delay vector includes:

a first substep for multiplying each element of said search direction vector by said adaptive gain (ρ

), which is generated from said step of synthesizing the adaptive gain;

a second substep for delaying the phase of oscillator output of which the frequency is the same as the carrier frequency of said received signal at said each antenna element by the amount determined by each corresponding element of said phase delay vector at the last previous snapshot;

a third substep for adding the outputs of said first substep and the outputs of said second substep, respectively; and

a fourth substep for generating the value of said phase delay vector at the present snapshot from the phase of each output of said third substep.

102. The signal processing method according to claim 101, wherein said step of updating said phase delay vector further includes:

a fifth substep for selecting the smaller element out of the first element and the last element of said phase delay vector, which is generated from said fourth substep at each snapshot; and

a sixth substep for subtracting the each output of said fifth substep from the output of said fourth substep.

103. A computer-readable medium having stored thereon computer-executable instructions for performing the steps comprising:

(a) synthesizing a residue vector by using a signal vector provided from an array antenna at each snapshot, a final array output signal of a telecommunication system at the last previous snapshot and a value of a gain vector of the present snapshot;

(b) synthesizing a scalar value, which is needed to generate a search direction vector, from said residue vector;

(c) producing a search direction vector by using said residue vector and said scalar value;

(d) producing an adaptive gain by using said signal vector, said search direction vector, said final array output signal of the telecommunication system at the last previous snapshot and the value of gain vector of the present snapshot; and

(e) updating said gain vector by using said search direction vector and said adaptive gain at the present snapshot.

104. A computer-readable medium having stored thereon computer-executable instructions for performing the steps comprising:

(a) generating an autocorrelation matrix from a signal vector provided from an array antenna at each snapshot;

(b) synthesizing a maximum eigenvalue of the autocorrelation matrix at each snapshot;

(c) synthesizing a residue vector from the autocorrelation matrix generated at each snapshot, the maximum eigenvalue, and a present value of a gain vector;

(d) synthesizing a scalar value, which is needed to generate a search direction vector, from said residue vector;

(e) synthesizing a search direction vector from said residue vector and said scalar value;

(f) synthesizing an adaptive gain from said autocorrelation matrix, said search direction vector, said maximum eigenvalue, and the present value of said gain vector; and

(g) updating said gain vector from said search direction vector and adaptive gain at each present snapshot.

105. A computer-readable medium having stored thereon computer-executable instructions for performing the steps comprising:

(a) generating a gamma vector and a zeta vector by approximating an autocorrelation matrix operations with a corresponding vector operations by utilizing a signal vector provided from an array antenna at each snapshot;

(b) estimating a maximum eigenvalue of autocorrelation matrix by utilizing a gain vector at present snapshot and said gamma vector;

(c) generating a residue vector by utilizing said gamma vector, said maximum eigenvalue of autocorrelation matrix, and said gain vector of the present snapshot;

(d) generating a scalar quantity by utilizing said residue vector;

(e) generating a search direction vector by utilizing said residue vector and said scalar quantity;

(f) generating an adaptive gain at each snapshot by utilizing said zeta vector, said search direction vector, said maximum eigenvalue of autocorrelation matrix, and said gain vector at the present snapshot; and

(g) updating said gain vector by utilizing said search direction vector and said adaptive gain at each snapshot.

106. A computer-readable medium having stored thereon computer-executable instructions for performing the steps comprising:

(a) synthesizing a residue vector, by utilizing received signals provided from an array antenna at each snapshot, a final array output signal of a telecommunication system at the last previous snapshot and a phase delay vector during the last previous snapshot,

(b) synthesizing a scalar value from said residue vector,

(c) synthesizing a search direction vector by using said residue vector and said scalar value;

(d) synthesizing a value of adaptive gain, by utilizing the received signals of present snapshot provided from the antenna elements, said final array output signal of said telecommunication system at the last previous snapshot, said search direction vector of the present snapshot and said phase delay vector during the last previous snapshot; and

(e) updating said phase delay vector by utilizing said search direction vector and said adaptive gain of the present snapshot.