Wireless communication system, and apparatus and method for wireless communication

• US 20080108314A1
• Filed: 10/12/2007
• Published: 05/08/2008
• Est. Priority Date: 11/08/2006
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Mihota, Norihito
• Granted Patent: US 8,000,301 B2
• Time in Patent Office: Days
• US Class Current: 455/101
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04B 7/0697 using spatial multiplexing

Abstract

An embodiment of the invention provides a wireless communication system for carrying out a spatial multiplexing communication between a transmitter, and a receiver, the system including: a channel information matrix acquiring section for acquiring a channel information matrix; a weighting factor matrix arithmetically operating section for obtaining a weighting factor matrix based on the channel information matrix thus acquired; a normalizing section for executing processing for normalizing the weighting factor matrix; a detecting section for detecting whether there is presence or absence of an abnormality in the processing; a weighting processing section for executing weighting processing based on the weighting factor matrix for each of transmission signals transmitted from the transmitter in accordance with a detection result obtained from the detecting section; and a transmitting section for transmitting the transmission signals for which the weighting processing section executes the weighting processing from the transmitter to the receiver.

Claims

1. A wireless communication system for carrying out a spatial multiplexing communication between a transmitter having a plurality of antennas, and a receiver having a plurality of antennas, the wireless communication system comprising:

channel information matrix acquiring means for acquiring a channel information matrix having transmission functions of the pairs of antennas between the sender side and the receiver side as elements;

weighting factor matrix arithmetically operating means for obtaining a weighting factor matrix based on the channel information matrix thus acquired;

normalizing means for executing processing for normalizing the weighting factor matrix;

detecting means for detecting whether there is presence or absence of an abnormality in the processing executed by the weighting factor matrix arithmetically operating means or the normalizing means;

weighting processing means for executing weighting processing based on the weighting factor matrix for each of transmission signals which are transmitted from the transmitter in accordance with a detection result obtained from the detecting means; and

transmitting means for transmitting the transmission signals for which the weighting processing means executes the weighting processing from the transmitter to the receiver.

2. The wireless communication system according to claim 1, wherein the normalizing means normalizes eigenvectors obtained from eigenvalues of a covariance matrix of the channel information matrix by the weighting factor matrix arithmetically operating means so that a row norm becomes a specified value.

3. The wireless communication system according to claim 1, wherein the detecting means detects that an input signal beyond a predetermined limit is input to the normalizing means, or that an overflow or an underflow occurs in a middle of the arithmetic operation for the normalization as an abnormality.

4. The wireless communication system according to claim 1, wherein when the detecting means detects the abnormality in the normalizing processing, the weighting processing means outputs another weighted transmission signals each having the row norm guaranteed therefore instead of weighting each of the transmission signals with a weighting factor matrix arithmetically operated by the weighting factor matrix arithmetically operating means.

5. The wireless communication system according to claim 4, further comprising nonvolatile memory means for previously storing one or more weighting matrices each having the row norm guaranteed therefore;

wherein when the detecting means detects the abnormality in the normalizing processing, the weighting processing means weights each of the transmission signals by using a weighting factor matrix previously stored in the nonvolatile memory means.

6. The wireless communication system according to claim 5, wherein the nonvolatile memory means previously stores a unit matrix, a rotation matrix having a suitable angle, a mirror matrix, a Walsh-Hadamard matrix, or a matrix obtained by combining these two or more matrices with each other.

7. The wireless communication system according to claim 5, wherein the nonvolatile memory means stores a plurality of different weighting factor matrices;

and

when the detecting means detects the abnormality in the normalizing processing, the weighting processing means suitably selects optimal one from among the plurality of different weighting factor matrices stored in the nonvolatile memory means, and weights each of the transmission signals with the weighting factor matrix thus selected.

8. The wireless communication system according to claim 5, wherein the nonvolatile memory means stores a plurality of rotation matrices having different angles, and;

when the detecting means detects the abnormality in the normalizing processing, the weighting processing means selects one having an angle nearest the weighting factor matrix before the normalization from among the plurality of rotation matrices stored in the nonvolatile memory means, and weights each of the transmission signals with the weighting factor matrix thus selected.

9. The wireless communication system according to claim 1, wherein the weighting factor matrix arithmetically operating means produces a plurality set of eigenvectors based on eigenvalues obtained from a covariance matrix of the channel information matrix thus acquired, and selects suitable one from among the plurality set of eigenvectors.

10. The wireless communication system according to claim 9, wherein the weighting factor matrix arithmetically operating means selects one having a low possibility that an arithmetic operation error finally occurs from among the plurality set of eigenvectors thus produced.

11. The wireless communication system according to claim 10, wherein each of the transmitter and the receiver includes two antennas;

and

the weighting factor matrix arithmetically operating means produces a weighting factor matrix based on a matrix V obtained by singular-value-decomposing the channel information matrix H thus acquired into UDV^H, sets elements of a covariance matrix A=H^HH of the channel information matrix H as └

[a₁₁,a₂₁]^T,[a₁₂,a₂₂]^T┘

, respectively, and sets eigenvalues of the covariance matrix A as λ

₁ and λ

₂ (λ

₁≧

λ

₂), respectively; and

when a₁₁>

a₂₂, or a₁₁≧

a₂₂, the weighting factor matrix arithmetically operating means selects eigenvectors [v₁,v₂] expressed by a following expression, and obtains a weighting factor matrix;

$\left[v_1,v_2\right]=\left[\begin{array}{cc}{k}_1<br><br>\left({\mathrm{\lambda <br><br>}}_1-a_{22}\right)& k_2<br><br>a_{12}\\ k_1<br><br>a_{21}& k_2<br><br>\left({\mathrm{\lambda <br><br>}}_2-a_{11}\right)\end{array}\right]$

where k₁ and k₂ are arbitrary numbers (each containing a real number and a complex number) other than zero,

and when a₁₁≦

a₂₂, or a₁₁<

a₂₂, the weighting factor matrix arithmetically operating means selects eigenvectors [v₁,v₂] expressed by a following expression, and obtains a weighting factor matrix;

$\left[v_1,v_2\right]=\left[\begin{array}{cc}{k}_3<br><br>a_{12}& k_4<br><br>\left({\mathrm{\lambda <br><br>}}_2-a_{22}\right)\\ k_3<br><br>\left({\mathrm{\lambda <br><br>}}_1-a_{11}\right)& k_4<br><br>a_{21}\end{array}\right]$

where k₃ and k₄ are arbitrary numbers (each containing a real number and a complex number) other than zero.

12. A wireless communication system for carrying out a spatial multiplexing communication between a transmitter having a plurality of antennas, and a receiver having a plurality of antennas, the wireless communication system comprising:

channel information matrix acquiring means for acquiring a channel information matrix having transmission functions of the pairs of antennas between the sender side and the receiver side as elements;

weighting factor matrix arithmetically operating means for obtaining a weighting factor matrix based on the channel information matrix thus acquired;

weighting processing means for executing weighting processing based on the weighting factor matrix for transmission signals which are transmitted from the transmitter;

transmission signal normalizing means for executing processing for normalizing each of the transmission signals weighted by the weighting processing means so that each of electric powers of the transmission signals from the respective transmitting antennas becomes a specified value;

matrix product arithmetically operating means for multiplying each of the transmission signals which are transmitted from the transmitter by a predetermined matrix, thereby weighting each of the transmission signals;

detecting means for detecting whether there is presence or absence of an abnormality in the processing executed by the weighting processing means or the normalizing means; and

transmitting means for transmitting one of the transmitting signal for which the weighting processing means executes the weighting processing, and the transmission signal obtained by the matrix product arithmetically operating means from the transmitter to the receiver in accordance with the detection result obtained from the detecting means.

13. The wireless communication system according to claim 12, wherein the detecting means detects that an input signal beyond a predetermined limit is input to the transmission signal normalizing means, or that an overflow or an underflow occurs in a middle of the arithmetic operation for the normalization as abnormality.

14. The wireless communication system according to claim 12, wherein the matrix product arithmetically operating means previously prepares a weighting factor matrix having a row norm guaranteed therefore, and multiplies each of the transmission signals which are transmitted from the transmitter by the weighting factor matrix to weight each of the transmission signals.

15. The wireless communication system according to claim 14, wherein the matrix product arithmetically operating means previously prepares a unit matrix, a rotation matrix having a suitable angle, a mirror matrix, a Walsh-Hadamard matrix, or a matrix obtained by combining these two or more matrices with each other.

16. A wireless communication apparatus including a plurality of antennas for carrying out a spatial multiplexing communication with a receiver having a plurality of antennas, the wireless communication apparatus comprising:

weighting factor matrix arithmetically operating means for obtaining a weighting factor matrix based on a channel information matrix having transmission functions of the pairs of antennas between the sender side and the receiver side as elements;

normalizing means for executing processing for normalizing the weighting factor matrix;

detecting means for detecting whether there is presence or absence of an abnormality in the processing executed by the weighting factor matrix arithmetically operating means or the normalizing means;

weighting processing means for executing weighting processing, based on the weighting factor matrix, for transmission signals in accordance with a detection result obtained from the detecting means; and

transmitting means for transmitting the weighted transmission signals through the antennas, respectively.

17. The wireless communication apparatus according to claim 16, wherein the normalizing means normalizes eigenvectors obtained from eigenvalues of a covariance matrix of the channel information matrix by the weighting factor matrix arithmetically operating means so that a row norm becomes a specified value.

18. The wireless communication apparatus according to claim 16, wherein the detecting means detects that an input signal beyond a predetermined limit is input to the normalizing means, or that an overflow or an underflow occurs in a middle of the arithmetic operation for the normalization as an abnormality.

19. The wireless communication apparatus according to claim 16, wherein when the detecting means detects the abnormality in the normalizing processing, the weighting processing means outputs another weighted transmission signals each having the row norm guaranteed therefore instead of weighting each of the transmission signals with a weighting factor matrix arithmetically operated by the weighting factor matrix arithmetically operating means.

20. The wireless communication apparatus according to claim 19, further comprising nonvolatile memory means for previously storing one or more weighting matrices each having the row norm guaranteed therefore;

wherein when the detecting means detects the abnormality in the normalizing processing, the weighting processing means weights each of the transmission signals by using a weighting factor matrix previously stored in the nonvolatile memory means.

21. The wireless communication apparatus according to claim 20, wherein the nonvolatile memory means previously stores a unit matrix, a rotation matrix having a suitable angle, a mirror matrix, a Walsh-Hadamard matrix, or a matrix obtained by combining these two or more matrices with each other.

22. The wireless communication apparatus according to claim 20, wherein the nonvolatile memory means stores a plurality of different weighting factor matrices;

and

when the detecting means detects the abnormality in the normalizing processing, the weighting processing means suitably selects optimal one from among the plurality of different weighting factor matrices stored in the nonvolatile memory means, and weights each of the transmission signals with the weighting factor matrix thus selected.

23. The wireless communication apparatus according to claim 20, wherein the nonvolatile memory means stores a plurality of rotation matrices having different angles;

and

when the detecting means detects the abnormality in the normalizing processing, the weighting processing means selects one having an angle nearest the weighting factor matrix before the normalization from among the plurality of rotation matrices stored in the nonvolatile memory means, and weights each of the transmission signals with the weighting factor matrix thus selected.

24. The wireless communication apparatus according to claim 16, wherein the weighting factor matrix arithmetically operating means produces a plurality set of eigenvectors based on eigenvalues obtained from a covariance matrix of the channel information matrix thus acquired, and selects suitable one from among the plurality set of eigenvectors.

25. The wireless communication apparatus according to claim 24, wherein the weighting factor matrix arithmetically operating means selects one having a low possibility that an arithmetic operation error finally occurs from among the plurality set of eigenvectors thus produced.

26. The wireless communication apparatus according to claim 25, wherein each of the transmitter and the receiver includes two antennas;

and

the weighting factor matrix arithmetically operating means produces a weighting factor matrix based on a matrix V obtained by singular-value-decomposing the channel information matrix H thus acquired into UDV^H, sets elements of a covariance matrix A=H^HH of the channel information matrix H as └

[a₁₁,a₂₁]^T,[a₁₂,a₂₂]^T┘

, respectively, and sets eigenvalues of the covariance matrix A as λ

₁ and λ

₂ (λ

₁≧

λ

₂), respectively; and

when a₁₁>

a₂₂, or a₁₁≧

a₂₂, the weighting factor matrix arithmetically operating means selects eigenvectors [v₁,v₂] expressed by a following expression, and obtains a weighting factor matrix;

$\left[v_1,v_2\right]=\left[\begin{array}{cc}{k}_1<br><br>\left({\mathrm{\lambda <br><br>}}_1-a_{22}\right)& k_2<br><br>a_{12}\\ k_1<br><br>a_{21}& k_2<br><br>\left({\mathrm{\lambda <br><br>}}_2-a_{11}\right)\end{array}\right]$

where k₁ and k₂ are arbitrary numbers (each containing a real number and a complex number) other than zero,

and when a₁₁≦

a₂₂, or a₁₁<

a₂₂, the weighting factor matrix arithmetically operating means selects eigenvectors [v₁,v₂] expressed by a following expression, and obtains a weighting factor matrix;

$\left[v_1,v_2\right]=\left[\begin{array}{cc}{k}_3<br><br>a_{12}& k_4<br><br>\left({\mathrm{\lambda <br><br>}}_2-a_{22}\right)\\ k_3<br><br>\left({\mathrm{\lambda <br><br>}}_1-a_{11}\right)& k_4<br><br>a_{21}\end{array}\right]$

where k₃ and k₄ are arbitrary numbers (each containing a real number and a complex number) other than zero.

27. A wireless communication apparatus including a plurality of antennas for carrying out a spatial multiplexing communication with a receiver having a plurality of antennas, the wireless communication apparatus comprising:

weighting factor matrix arithmetically operating means for obtaining a weighting factor matrix based on a channel information matrix having transmission functions of the pairs of antennas between the sender side and the receiver side as elements;

weighting processing means for executing weighting processing, based on the weighting factor matrix, for transmission signals which are transmitted through the antennas, respectively;

transmission signal normalizing means for executing processing for normalizing each of the transmission signals weighted by the weighting processing means so that each of electric powers of the transmission signals from the respective transmitting antennas becomes a specified value;

matrix product arithmetically operating means for multiplying each of the transmission signals which are transmitted through the antennas, respectively, by a predetermined matrix, thereby weighting each of the transmission signals concerned;

detecting means for detecting whether there is presence or absence of an abnormality in the processing executed by the weighting processing means or the normalizing section; and

transmitting means for transmitting one of the transmitting signal for which the weighting processing means executes the weighting processing, and the transmission signal obtained by the matrix product arithmetically operating means from the transmitter to the receiver in accordance with the detection result obtained from the detecting means.

28. The wireless communication apparatus according to claim 27, wherein the detecting means detects that an input signal beyond a predetermined limit is input to the transmission signal normalizing means, or that an overflow or an underflow occurs in a middle of the arithmetic operation for the normalization as abnormality.

29. The wireless communication apparatus according to claim 27, wherein the matrix product arithmetically operating means previously prepares a weighting factor matrix having a row norm guaranteed therefore, and multiplies each of the transmission signals which are transmitted from the transmitter by the weighting factor matrix to weight each of the transmission signals.

30. The wireless communication apparatus according to claim 29, wherein the matrix product arithmetically operating means previously prepares a unit matrix, a rotation matrix having a suitable angle, a mirror matrix, a Walsh-Hadamard matrix, or a matrix obtained by combining these two or more matrices with each other.

31. A wireless communication method of carrying out a spatial multiplexing communication with a receiver having a plurality of antennas by using a plurality of antennas, the wireless communication method comprising the steps of:

arithmetically operating a weighting factor matrix based on a channel information matrix having transmission functions of the pairs of antennas between the sender side and the receiver side as elements;

executing processing for normalizing the weighting factor matrix;

detecting whether there is presence or absence of an abnormality in the weighting factor matrix arithmetically operating step or in the normalizing step;

executing weighting processing, based on the weighting factor matrix, for each of transmission signals in accordance with a detection result obtained in the detecting step; and

transmitting the weighted transmission signals through the antennas, respectively.

32. The wireless communication method according to claim 31, wherein in the normalizing step, eigenvectors obtained from eigenvalues of a covariance matrix of the channel information matrix in the weighting factor matrix arithmetically operating step is normalized so that a row norm becomes a specified value.

33. The wireless communication method according to claim 31, wherein in the detecting step, it is detected as an abnormality in the normalizing processing that an input signal beyond a predetermined limit is input to the normalizing step, or that an overflow or an underflow occurs in a middle of the arithmetic operation for the normalization.

34. The wireless communication method according to claim 31, wherein in the weighting processing step, when the abnormality in the normalizing processing is detected in the detecting step, another weighted transmission signals each having the row norm guaranteed therefore is output instead of weighting each of the transmission signals with a weighting factor matrix arithmetically operated in the weighting factor matrix arithmetically operating step.

35. The wireless communication method according to claim 34, wherein in the weighting processing step, when the abnormality in the normalizing processing is detected in the detecting step, each of the transmission signals weighted with a weighting factor matrix, each having a row norm guaranteed therefore, which is previously prepared.

36. The wireless communication method according to claim 35, wherein in the weighting processing step, when the abnormality in the normalizing processing is detected in the detecting step, each of the transmission signals is weighted with any one of a unit matrix, a rotation matrix having a suitable angle, a mirror matrix, a Walsh-Hadamard matrix, and a matrix obtained by combining these two or more matrices with each other.

37. The wireless communication method according to claim 35, wherein in the weighting processing step, when the abnormality in the normalizing processing is detected in the detecting step, optimal one is suitably selected from among a plurality of weighting factor matrices, each having a row norm guaranteed therefore, which are previously prepared, and each of the transmission signals is weighted with the optimal weighting factor matrix thus selected.

38. The wireless communication method according to claim 35, wherein the plurality of weighting factor matrices previously prepared are a plurality of rotation matrices having different angles;

and

in the weighting processing step, when the abnormality in the normalizing processing is detected in the detecting step, one having the angle nearest the weighting factor matrix before the normalization in the normalizing step is selected from among the plurality of rotation matrices, and each of the transmission signals is weighted with the rotation matrix thus selected.

39. The wireless communication method according to claim 31, wherein in the weighting factor matrix arithmetically operating step, a plurality set of eigenvectors are produced based on eigenvalues obtained from a covariance matrix of the channel information matrix thus acquired, and suitable one is selected from among the plurality set of eigenvectors.

40. The wireless communication method according to claim 39, wherein in the weighting factor matrix arithmetically operating step, one having a low possibility that an arithmetic operation error finally occurs is selected from among the plurality set of eigenvectors thus produced.

41. The wireless communication method according to claim 40, wherein the two antennas are used, and the receiver includes the two antennas;

in the weighting factor matrix arithmetically operating step, a weighting factor matrix is produced based on a matrix V obtained by singular-value-decomposing decomposing the channel information matrix H thus acquired into UDV^H, elements of a covariance matrix A=H^HH of the channel information matrix H are set as └

[a₁₁,a₂₁]^T,[a₁₂,a₂₂]^T┘

, respectively, and eigenvalues of the covariance matrix A are set as λ

₁ and λ

₂ (λ

₁≧

λ

₂), respectively; and

when a₁₁>

a₂₂, or a₁₁≧

a₂₂, eigenvectors [v₁,v₂] expressed by a following expression are selected, and a weighting factor matrix is obtained;

$\left[v_1,v_2\right]=\left[\begin{array}{cc}{k}_1<br><br>\left({\mathrm{\lambda <br><br>}}_1-a_{22}\right)& k_2<br><br>a_{12}\\ k_1<br><br>a_{21}& k_2<br><br>\left({\mathrm{\lambda <br><br>}}_2-a_{11}\right)\end{array}\right]$

where k₁ and k₂ are arbitrary numbers (each containing a real number and a complex number) other than zero,

and when a₁₁≦

a₂₂, or a₁₁ <

a₂₂, eigenvectors [v₁,v₂] expressed by a following expression are selected, and a weighting factor matrix is obtained;

$\left[v_1,v_2\right]=\left[\begin{array}{cc}{k}_3<br><br>a_{12}& k_4<br><br>\left({\mathrm{\lambda <br><br>}}_2-a_{22}\right)\\ k_3<br><br>\left({\mathrm{\lambda <br><br>}}_1-a_{11}\right)& k_4<br><br>a_{21}\end{array}\right]$

where k₃ and k₄ are arbitrary numbers (each containing a real number and a complex number) other than zero.

42. A wireless communication method of carrying out a spatial multiplexing communication with a receiver having a plurality of antennas by using a plurality of antennas, the wireless communication method comprising the steps of:

arithmetically operating a weighting factor matrix based on a channel information matrix having transmission functions of the pairs of antennas between the sender side and the receiver side as elements;

executing weighting processing, based on the weighting factor matrix, for each of transmission signals which are transmitted through the antennas, respectively;

executing processing for normalizing each of the transmission signals weighted in the weighting processing so that each of electric powers of the transmission signals which are transmitted through the transmission antennas, respectively, becomes a specified value;

multiplexing each of the transmission signals which are transmitted through the antennas, respectively, by a predetermined matrix, thereby weighting each of the transmission signals;

detecting whether there is presence or absence of an abnormality in the processing executed in the weighting processing step or in the normalizing step; and

transmitting one of the transmission signal for which the weighting processing is executed in the weighting processing step, and the transmission signal obtained in the matrix product arithmetically operating step in accordance with a detection result obtained in the detecting step.

43. The wireless communication method according to claim 42, wherein in the detecting step, it is detected as an abnormality in the processing that an input signal beyond a predetermined limit is input to the transmission signal normalizing step, or that an overflow or an underflow occurs in a middle of the arithmetic operation for the normalization.

44. The wireless communication method according to claim 42, wherein in the matrix product arithmetically operating step, each of the transmission signals which are transmitted through the antennas, respectively, is weighted with a weighting factor matrix having a row norm guaranteed therefore.

45. The wireless communication method according to claim 44, wherein in the matrix product arithmetically operating step, a unit matrix, a rotation matrix having a suitable angle, a mirror matrix, a Walsh-Hadamard matrix, or a matrix obtained by combining these two or more matrices with each other is used.

46. A wireless communication system for carrying out a spatial multiplexing communication between a transmitter having a plurality of antennas, and a receiver having a plurality of antennas, the wireless communication system comprising:

a channel information matrix acquiring section configured to acquire a channel information matrix having transmission functions of the pairs of antennas between the sender side and the receiver side as elements;

a weighting factor matrix arithmetically operating section configured to obtain a weighting factor matrix based on the channel information matrix thus acquired;

a normalizing section configured to execute processing for normalizing the weighting factor matrix;

a detecting section configured to detect whether there is presence or absence of an abnormality in the processing executed by the weighting factor matrix arithmetically operating section or the normalizing section;

a weighting processing section configured to execute weighting processing based on the weighting factor matrix for each of transmission signals which are transmitted from the transmitter in accordance with a detection result obtained from the detecting section; and

a transmitting section configured to transmit the transmission signals for which the weighting processing section executes the weighting processing from the transmitter to the receiver.

47. A wireless communication system for carrying out a spatial multiplexing communication between a transmitter having a plurality of antennas, and a receiver having a plurality of antennas, the wireless communication system comprising:

a channel information matrix acquiring section configured to acquire a channel information matrix having transmission functions of the pairs of antennas between the sender side and the receiver side as elements;

a weighting factor matrix arithmetically operating section configured to obtain a weighting factor matrix based on the channel information matrix thus acquired;

a weighting processing section configured to execute weighting processing based on the weighting factor matrix for transmission signals which are transmitted from the transmitter;

a transmission signal normalizing section configured to execute processing for normalizing each of the transmission signals weighted by the weighting processing section so that each of electric powers of the transmission signals from the respective transmitting antennas becomes a specified value;

a matrix product arithmetically operating section configured to multiply each of the transmission signals which are transmitted from the transmitter by a predetermined matrix, thereby weighting each of the transmission signals;

a detecting section configured to detect whether there is presence or absence of an abnormality in the processing executed by the weighting processing section or the normalizing section; and

a transmitting section configured to transmit one of the transmitting signal for which the weighting processing section executes the weighting processing, and the transmission signal obtained by the matrix product arithmetically operating section from the transmitter to the receiver in accordance with the detection result obtained from the detecting section.

48. A wireless communication apparatus including a plurality of antennas for carrying out a spatial multiplexing communication with a receiver having a plurality of antennas, the wireless communication apparatus comprising:

a weighting factor matrix arithmetically operating section configured to obtain a weighting factor matrix based on a channel information matrix having transmission functions of the pairs of antennas between the sender side and the receiver side as elements;

a normalizing section configured to execute processing for normalizing the weighting factor matrix;

a detecting section configured to detect whether there is presence or absence of an abnormality in the processing executed by the weighting factor matrix arithmetically operating section or the normalizing section;

a weighting processing section configured to execute weighting processing, based on the weighting factor matrix, for transmission signals in accordance with a detection result obtained from the detecting section; and

a transmitting section configured to transmit the weighted transmission signals through the antennas, respectively.

49. A wireless communication apparatus including a plurality of antennas for carrying out a spatial multiplexing communication with a receiver having a plurality of antennas, the wireless communication apparatus comprising:

a weighting factor matrix arithmetically operating section configured to obtain a weighting factor matrix based on a channel information matrix having transmission functions of the pairs of antennas between the sender side and the receiver side as elements;

a weighting processing section configured to execute weighting processing, based on the weighting factor matrix, for transmission signals which are transmitted through the antennas, respectively;

a transmission signal normalizing section configured to executing processing for normalizing each of the transmission signals weighted by the weighting processing section so that each of electric powers of the transmission signals from the respective transmitting antennas becomes a specified value;

a matrix product arithmetically operating section configured to multiply each of the transmission signals which are transmitted through the antennas, respectively, by a predetermined matrix, thereby weighting each of the transmission signals concerned;

a detecting section configured to detect whether there is presence or absence of an abnormality in the processing executed by the weighting processing section or the normalizing section; and

a transmitting section configured to transmit one of the transmitting signal for which the weighting processing section executes the weighting processing, and the transmission signal obtained by the matrix product arithmetically operating section from the transmitter to the receiver in accordance with the detection result obtained from the detecting section.