System and method for wireless communication systems

• US 7,327,795 B2
• Filed: 03/31/2003
• Issued: 02/05/2008
• Est. Priority Date: 03/31/2003
• Status: Active Grant

• Current Assignee: Vecima Networks Incorporated
• Original Assignee: Vecima Networks Incorporated
• Inventors: Oprea, Alexandru M.
• Primary Examiner(s): Fan; Chieh M.
• Assistant Examiner(s): Joseph; Jaison
• Application Number:
  US10/401,955
• Publication Number:
  US 20040190636A1
• Time in Patent Office: 1,772 Days
• Field of Search: 375/260, 375/267, 375/140, 375/156, 375/147, 375/152, 375/295, 375/340, 375/347, 370208-210, 370/203, 370/280, 370/345, 370/441, 370/442, 370/465, 370/319, 370/480
• US Class Current: 375/260
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0443 utilizing "waterfilling" technique
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0848 Joint weighting
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0643 block codes
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

A system and method for transmitting a plurality of input data symbol sub-streams over a plurality of spatial-subspace channels of a sub-carrier between a transmitter and the receiver. The plurality of input data symbol sub-streams are partitioned in a plurality of super-frames of data and weighted by a weight matrix derived from the singular value decomposition of a channel matrix corresponding to the sub-carrier by applying a partial SVD algorithm. The transmitter further inserts subspace training symbols into the plurality of input data symbol sub-streams and the receiver periodically processes the sub-space training symbols during each super-frame of the plurality of super-frames for estimating output data related to the input data symbol stream.

Claims

1. A transmitter for processing an input data symbol stream for transmission over a plurality of spatial-subspace channels of a sub-carrier, wherein said transmitter comprises:

a transmitter Singular Value Decomposition (SVD) unit for calculating an approximation of a transmit weight matrix from a channel matrix corresponding to said sub-carrier by applying a partial SVD algorithm in which said transmitter SVD unit truncates an interim version of said transmit weight matrix to calculate said approximation of said transmit weight matrix; and

,

a transmitter weighting unit connected to said transmitter SVD unit for weighting a plurality of input data symbol sub-streams with said approximation of said transmit weight matrix for distributing said plurality of input data symbol sub-streams along said plurality of spatial-subspace channels, said plurality of input data symbol sub-streams being derived from said input data symbol stream,

wherein said transmitter SVD unit is configured to performs said partial SVD algorithm by performing n1 iterations of an iterative SVD algorithm on said channel matrix to obtain an interim singular value matrix Λ

_k′ and

interim weight matrices U_k′ and

V_k′

, said interim weight matrix V_k′

being said interim version of said transmit weight matrix, and wherein said transmitter SVD unit is further configured to determines a number p of said plurality of spatial-subspace channels, and truncates and zero-pads said interim matrices Λ

_k′

, U_k′ and

V_k′

to obtain truncated matrices Λ

_k″

, U_k″ and

V_k″

;

where n1 and p are positive integers.

2. The transmitter of claim 1, wherein said transmitter SVD unit is further configured to performs n2 iterations of said iterative SVD algorithm on said truncated matrices U_k″

, Λ

_k″ and

V_k″

to obtain an approximate singular value matrix Λ

_k and said approximation of said transmit weight matrix;

where n2 is a positive integer.

3. The transmitter of claim 2, wherein n1 and n2 are constant integers.

4. The transmitter of claim 3, wherein said constant integers are chosen from the range comprising integers 1 to 4.

5. The transmitter of claim 1, wherein n1 is a variable integer bounded by a constant nmax1 and n1 is determined by performing said iterative SVD algorithm until a sum of squared magnitudes of off-diagonal components of said interim matrix Λ

_k′

is less than or equal to a pre-specified fraction of a sum of squared magnitudes of diagonal components of said interim matrix Λ

_k′

.

6. The transmitter of claim 2, wherein n2 is a variable integer bounded by a constant nmax2, and n2 is determined by performing said iterative SVD algorithm until a sum of squared magnitudes of off-diagonal components of said truncated matrix Λ

_k″

is less than or equal to a pre-specified fraction of a sum of squared magnitudes of diagonal components of said truncated matrix Λ

_k″

.

7. The transmitter of claim 2, wherein said transmitter SVD unit is further configured to apply the partial SVD algorithm to said approximate singular value matrix Λ

_k.

43. The transmitter of claim 1, wherein said n1 iterations are performed until, in said interim singular value matrix Λ

_k′

, a first upper group of diagonal components have much larger values than a second lower group of diagonal components and off-diagonal components have small but non-zero values.

44. The transmitter of claim 1, wherein said p number of spatial-subspace channels is determined by applying a threshold to magnitudes of singular values of said interim singular value matrix Λ

_k′

.

45. The transmitter of claim 1, wherein said p number of spatial-subspace channels is determined by choosing a pre-specified number which is determined experimentally by examining a plurality of estimated channel matrices.

8. A receiver for processing received spatial-subspace data on a plurality of spatial-subspace channels of a sub-carrier, wherein said receiver comprises:

a) a receiver Singular Value Decomposition (SVD) unit for calculating an approximation of a receive weight matrix from a channel matrix corresponding to said sub-carrier by applying a partial SVD algorithm in which said receiver SVD unit truncates an interim version of said receive weight matrix to calculate said approximation of said receive weight matrix; and

,

b) a receiver weighting unit connected to said receiver SVD unit for weighting said received spatial-subspace data with said approximation of said receive weight matrix,

wherein said receiver SVD unit is configured to performs said partial SVD algorithm by performing n1 iterations of an iterative SVD algorithm on said channel matrix to obtain an interim singular value matrix Λ

_k′ and

interim weight matrices U_k′ and

V_k′

, a complex conjugate transpose of said interim weight matrix U_k′

being said interim version of said receive weight matrix, and wherein said receiver SVD unit is further configured to determine a number p of said plurality of spatial-subspace channels and truncates and zero-pads said interim matrices Λ

_k′

, U_k′ and

V_k′

to obtain truncated matrices Λ

_k″

, U_k″ and

V_k″

, where n1 and p are positive integers.

9. The transmitter of claim 8, wherein said transmitter SVD unit is further configured to performs n2 iterations of said iterative SVD algorithm on said truncated matrices U_k″

, Λ

_k″ and

V_k″

to obtain an approximate singular value matrix Λ

_k and said approximation of said transmit weight matrix;

where n2 is a positive integer.

10. The receiver of claim 9, wherein n1 and n2 are constant integers.

11. The receiver of claim 10, wherein said constant integers are chosen from the range comprising integers 1 to 4.

12. The receiver of claim 8, wherein n1 is a variable integer bounded by a constant nmax1, and n1 is determined by performing said iterative SVD algorithm until a sum of squared magnitudes of off-diagonal components of said interim matrix Λ

_k′

is less than a pre-specified fraction of a sum of squared magnitudes of diagonal components of said interim matrix Λ

_k′

.

13. The receiver of claim 9, wherein n2 is a variable integer bounded by a constant nmax2, and n2 is determined by performing said iterative SVD algorithm until a sum of squared magnitudes of off-diagonal components of said truncated matrix Λ

_k″

is less than a pre-specified fraction of a sum of squared magnitudes of diagonal components of said truncated matrix Λ

_k″

.

14. The receiver of claim 9, wherein said receiver SVD unit is further configured to apply the partial SVD algorithm to said approximate singular value matrix Λ

_k.

46. The receiver of claim 8, wherein said n1 iterations are performed until, in said interim singular value matrix Λ

_k′

, a first upper group of diagonal components have much larger values than a second lower group of diagonal components and off-diagonal components have small but non-zero values.

47. The receiver of claim 8, wherein said p number of spatial-subspace channels is determined by applying a threshold to magnitudes of singular values of said interim singular value matrix Λ

_k′

.

48. The receiver of claim 8, wherein said p number of spatial-subspace channels is determined by choosing a pre-specified number which is determined experimentally by examining a plurality of estimated channel matrices.

15. A method for processing an input data symbol stream for transmission over a plurality of spatial-subspace channels of a sub-carrier, wherein said method comprises:

a) calculating an approximation of a transmit weight matrix from a channel matrix corresponding to said sub-carrier by applying a partial Singular Value Decomposition (SVD) algorithm which comprises truncating an interim version of said transmit weight matrix to calculate said approximation of said transmit weight matrix; and

,

b) weighting a plurality of input data symbol sub-streams with said approximation of said transmit weight matrix for distributing said plurality of input data symbol sub-streams along said plurality of spatial-subspace channels, said plurality of input data symbol sub-streams being derived from said input data symbol stream

wherein applying said partial SVD algorithm comprises;

c) performing n1 iterations of an iterative SVD algorithm on said channel matrix to obtain an interim singular value matrix Λ

_k′ and

interim weight matrices U_k′ and

V_k′

, said interim weight matrix V_k′

being said interim version of said transmit weight matrix;

d) determining a number p of said plurality of spatial-subspace channels; and

,

e) truncating and zero-padding said interim matrices Λ

_k′

, U_k′ and

V_k′

to obtain truncated matrices Λ

_k″

, U_k″ and

V_k″

, where n1 and p are positive integers.

16. The method of claim 15, wherein, applying said partial SVD algorithm further comprises:

f) performing n2 iterations of said iterative SVD algorithm on said truncated matrices U_k″

, Λ

_k″ and

V_k″

to obtain an approximate singular value matrix Λ

_k and said approximation of said transmit weight matrix, where n2 is a positive integer.

17. The method of claim 16, wherein n1 and n2 are constant integers.

18. The method of claim 17, wherein said constant integers are chosen from the range comprising integers 1 to 4.

19. The method of claim 15, wherein n1 is a variable integer bounded by a constant nmax1, and n1 is determined by performing said iterative SVD algorithm until a sum of squared magnitudes of off-diagonal components of said interim matrix Λ

_k′

is less than a pre-specified fraction of a sum of squared magnitudes of diagonal components of said interim matrix Λ

_k′

.

20. The method of claim 16, wherein n2 is a variable integer bounded by a constant nmax2, and n2 is determined by performing said iterative SVD algorithm until a sum of squared magnitudes of off-diagonal components of said truncated matrix Λ

_k″

is less than a pre-specified fraction of a sum of squared magnitudes of diagonal components of said truncated matrix Λ

_k″

.

21. The method of claim 16, wherein said method further comprises applying steps (a) to (f) of said partial SVD algorithm to said approximate singular value matrix Λ

_k.

49. The method of claim 15, wherein the method comprises performing said n1 iterations until, in said interim singular value matrix Λ

_k′

, a first upper group of diagonal components have much larger values than a second lower group of diagonal components and off-diagonal components have small but non-zero values.

50. The method of claim 15, wherein the method comprises determining said p number of spatial-subspace channels by applying a threshold to magnitudes of singular values of said interim singular value matrix Λ

_k′

.

51. The method of claim 15, wherein the method comprises determining said p number of spatial-subspace channels by choosing a pre-specified number which is determined experimentally by examining a plurality of estimated channel matrices.

22. A method for processing received spatial-subspace data on a plurality of spatial-subspace channels of a sub-carrier, wherein said method comprises:

a) calculating an approximation of a receive weight matrix from a channel matrix corresponding to said sub-carrier by applying a partial Singular Value Decomposition (SVD) algorithm which comprises truncating an interim version of said receive weight matrix to calculate said approximation of said receive weight matrix; and

,

b) weighting said received spatial-subspace data with said approximation of said receive weight matrix,

wherein applying said partial SVD algorithm comprises;

c) performing n1 iterations of an iterative SVD algorithm on said channel matrix to obtain an interim singular value matrix, ˜

′ and

interim weight matrices U_k′ and

V_k′

, a complex-conjugate transpose of said interim weight matrix U_k′

being said interim version of said receive weight matrix;

d) determining a number p of said plurality of spatial-subspace channels; and

,

e) truncating and zero-padding said interim matrices Λ

_k′

, U_k′ and

V_k′

to obtain truncated matrices Λ

_k″

, U_k″ and

V_k″

, where n1 and p are positive integers.

23. The method of claim 22, wherein, applying said partial SVD algorithm further comprises:

f) performing n2 iterations of said iterative SVD algorithm on said truncated matrices U_k41 , Λ

_k″ and

V_k″

to obtain an approximate singular value matrix Λ

_k and said approximation of said receive weight matrix, where n2 is a positive integer.

24. The method of claim 23, wherein n1 and n2 are constant integers.

25. The method of claim 24, wherein said constant integers are chosen from the range comprising integers 1 to 4.

26. The method of claim 22, wherein n1 is a variable integer bounded by a constant nmax1, and n1 is determined by performing said iterative SVD algorithm until a sum of squared magnitudes of off-diagonal components of said interim matrix Λ

_k′

is less than a pre-specified fraction of a sum of squared magnitudes of diagonal components of said interim matrix Λ

_k′

.

27. The method of claim 23, wherein n2 is a variable integer bounded by a constant nmax2, and n2 is determined by performing said iterative SVD algorithm until a sum of squared magnitudes of off-diagonal components of said truncated matrix Λ

_k″

is less than a pre-specified fraction of a sum of squared magnitudes of diagonal components of said truncated matrix Λ

_k″

.

28. The method of claim 23, wherein said method further comprises applying steps (a) to (f) of said partial SVD algorithm to said approximate singular value matrix Λ

_k.

52. The method of claim 22, wherein the method comprises performing said n1 iterations until, in said interim singular value matrix Λ

_k′

, a first upper group of diagonal components have much larger values than a second lower group of diagonal components and off-diagonal components have small but non-zero values.

53. The method of claim 22, wherein the method comprises determining said p number of spatial-subspace channels by applying a threshold to magnitudes of singular values of said interim singular value matrix Λ

_k′

.

54. The method of claim 22, wherein the method comprises determining said p number of spatial-subspace channels by choosing a pre-specified number which is determined experimentally by examining a plurality of estimated channel matrices.

29. A communication system comprising a transmitter having a transmitter antenna array and a receiver having a receiver antenna array, wherein said communication system is configured to transmit an input data symbol stream over a plurality of spatial-subspace channels of a sub-carrier between said transmitter and said receiver, said input data symbol stream being partitioned into a plurality of super-frames, wherein said transmitter further comprises:

a) a subspace training unit for inserting subspace training symbols into a plurality of input data symbol sub-streams and producing a plurality of input data/training symbol sub-streams, said plurality of input data symbol sub-streams being derived from said input data symbol stream;

b) a transmitter Singular Value Decomposition (SVD) unit for providing a transmit weight matrix corresponding to said sub-carrier at a beginning of each super-frame in said plurality of super-frames; and

,

c) a transmitter weighting unit connected to said subspace training unit and said transmitter SVD unit for weighting said plurality of input data/training symbol sub-streams with said transmit weight matrix for distributing said plurality of input data/training symbol sub-streams along said plurality of spatial-subspace channels and providing transmit-weighted spatial-subspace data;

and said receiver further comprises;

d) a receiver SVD unit connected for providing a receive weight matrix corresponding to said sub-carrier and an initial estimate of a corresponding singular value matrix at a beginning of each super-frame of said plurality of super-frames;

e) a receiver weighting unit connected to said receiver SVD unit for receiving received spatial-subspace data related to said transmit-weighted spatial-subspace data and weighting said received spatial-subspace data with said receive weight matrix for providing receive-weighted spatial-subspace data, said receive-weighted spatial-subspace data containing received subspace training symbols;

f) a receiver link adaptation unit connected to said receiver weighting unit and said receiver SVD unit for receiving said initial estimate of said corresponding singular value matrix and processing said received subspace training symbols for periodically providing undated estimates of said corresponding singular value matrix during each super-frame of said plurality of super-frames; and

,

g) a data estimation unit connected to said receiver weighting unit and said receiver link adaptation unit for receiving said receive-weighted spatial-subspace data, said initial estimate of said corresponding singular value matrix and said undated estimates of said corresponding singular value matrix and providing said estimated output data during each super-frame of said plurality of super-frames,

wherein said receiver is configured to periodically process said sub-space training symbols during each super-frame of said plurality of super-frames for estimating output data related to said input data symbol stream, and wherein said transmitter further comprises an encoder unit connected to said subspace training unit for processing said plurality of input data symbol sub-streams for providing at least one of;

     1) at least one uncoded data symbol sub-stream for allocation on a corresponding at least one uncoded spatial-subspace channel and

     2) at least one pair of coded data symbol sub-streams for allocation on a corresponding at least one pair of coded spatial-subspace channels and wherein said plurality of spatial-subspace channels comprise only uncoded spatial-subspace channels and said data estimation unit is adapted to perform a successive interference cancellation method for providing said estimated output data by detecting receive-weighted data symbols on one of said uncoded spatial-subspace channels, subtracting the detected receive-weighted data symbols from the receive-weighted spatial-subspace data and processing remaining uncoded spatial-subspace channels in a similar fashion wherein the uncoded spatial-subspace channels are processed in order of decreasing signal to noise plus interference ratio.

30. A communication system comprising a transmitter having a transmitter antenna array and a receiver having a receiver antenna array, wherein said communication system is configured to transmit an input data symbol stream over a plurality of spatial-subspace channels of a sub-carrier between said transmitter and said receiver, said input data symbol stream being partitioned into a plurality of super-frames, wherein said transmitter further comprises:

a) a subspace training unit for inserting subspace training symbols into a plurality of input data symbol sub-streams and producing a plurality of input data/training symbol sub-streams, said plurality of input data symbol sub-streams being derived from said input data symbol stream;

b) a transmitter Singular Value Decomposition (SVD) unit for providing a transmit weight matrix corresponding to said sub-carrier at a beginning of each super-frame in said plurality of super-frames; and

,

c) a transmitter weighting unit connected to said subspace training unit and said transmitter SVD unit for weighting said plurality of input data/training symbol sub-streams with said transmit weight matrix for distributing said plurality of input data/training symbol sub-streams along said plurality of spatial-subspace channels and providing transmit-weighted spatial-subspace data;

and said receiver further comprises;

d) a receiver SVD unit connected for providing a receive weight matrix corresponding to said sub-carrier and an initial estimate of a corresponding singular value matrix at a beginning of each super-frame of said plurality of super-frames;

e) a receiver weighting unit connected to said receiver SVD unit for receiving received spatial-subspace data related to said transmit-weighted spatial-subspace data and weighting said received spatial-subspace data with said receive weight matrix for providing receive-weighted spatial-subspace data, said receive-weighted spatial-subspace data containing received subspace training symbols;

f) a receiver link adaptation unit connected to said receiver weighting unit and said receiver SVD unit for receiving said initial estimate of said corresponding singular value matrix and processing said received subspace training symbols for periodically providing updated estimates of said corresponding singular value matrix during each super-frame of said plurality of super-frames; and

,

g) a data estimation unit connected to said receiver weighting unit and said receiver link adaptation unit for receiving said receive-weighted spatial-subspace data, said initial estimate of said corresponding singular value matrix and said undated estimates of said corresponding singular value matrix and providing said estimated output data during each super-frame of said plurality of super-frames

wherein, said receiver is configured to periodically process said sub-space training symbols during each super-frame of said plurality of super-frames for estimating output data related to said input data symbol stream, said transmitter further comprises an encoder unit connected to said subspace training unit for processing said plurality of input data symbol sub-streams for providing at least one of;

     1) at least one uncoded data symbol sub-stream for allocation on a corresponding at least one uncoded spatial-subspace channel and

     2) at least one pair of coded data symbol sub-streams for allocation on a corresponding at least one pair of coded spatial-subspace channels and, wherein said plurality of spatial-subspace channels comprise coded spatial-subspace channels and uncoded spatial-subspace channels and said data estimation unit is adapted to perform an iterative decoding/detection method on the receive-weighted spatial-subspace data for providing said estimated output data, with one iteration of said decoding/detection method comprising;

     1) decoding and detecting receive-weighted coded data symbols transmitted on said coded spatial-subspace channels and replacing said receive-weighted coded data symbols in said receive-weighted spatial-subspace data with detected coded data symbols; and

,

     2) estimating and detecting receive-weighted uncoded data symbols transmitted on said uncoded spatial-subspace channels.

31. A communication system comprising a transmitter having a transmitter antenna array and a receiver having a receiver antenna array, wherein said communication system is configured to transmit an input data symbol stream over a plurality of spatial-subspace channels of a sub-carrier between said transmitter and said receiver, said input data symbol stream being partitioned into a plurality of super-frames, wherein said transmitter further comprises:

a) a subspace training unit for inserting subspace training symbols into a plurality of input data symbol sub-streams and producing a plurality of input data/training symbol sub-streams, said plurality of input data symbol sub-streams being derived from said input data symbol stream;

b) a transmitter Singular Value Decomposition (SVD) unit for providing a transmit weight matrix corresponding to said sub-carrier at a beginning of each super-frame in said plurality of super-frames; and

,

c) a transmitter weighting unit connected to said subspace training unit and said transmitter SVD unit for weighting said plurality of input data/training symbol sub-streams with said transmit weight matrix for distributing said plurality of input data/training symbol sub-streams along said plurality of spatial-subspace channels and providing weighted spatial-subspace data;

wherein, said receiver is configured to periodically process said sub-space training symbols during each super-frame of said plurality of super-frames for estimating output data related to said input data symbol stream, said transmitter SVD unit is configured to calculate an approximation of said transmit weight matrix from a channel matrix corresponding to said sub-carrier by applying a partial SVD algorithm in which said transmitter SVD unit is configured to truncate an interim version of said transmit weight matrix to calculate said approximation of said transmit weight matrix, and said transmitter SVD unit is configured to performs said partial SVD algorithm by performing n1 iterations of an iterative SVD algorithm on said channel matrix to obtain an interim singular value matrix Λ

_k′ and

interim weight matrices U_k′ and

V_k′

, said interim weight matrix V_k′

being said interim version of said transmit weight matrix, wherein said transmitter SVD unit is further configured to determines a number p of said plurality of spatial-subspace channels, and truncates and zero-pads said interim matrices Λ

_k′

, U_k′ and

V_k′

to obtain truncated matrices Λ

_k″

, U_k″ and

V_k″

, where n1 and p are positive integers.

32. The communication system of claim 31, wherein said transmitter SVD unit is further configured to performs n2 iterations of said iterative SVD algorithm on said truncated matrices U_k″

, Λ

_k″

, and V_k″

to obtain an approximate singular value matrix Λ

_k and said approximation of said transmit weight matrix, where n2 is a positive integer.

33. The communication system of claim 32, wherein said transmitter SVD unit is further configured to apply the partial SVD algorithm to said approximate singular value matrix Λ

_k.

34. A communication system comprising a transmitter having a transmitter antenna array and a receiver having a receiver antenna array, wherein said communication system is configured to transmit an input data symbol stream over a plurality of spatial-subspace channels of a sub-carrier between said transmitter and said receiver, said input data symbol stream being partitioned into a plurality of super-frames, wherein said transmitter further comprises:

a) a subspace training unit for inserting subspace training symbols, into a plurality of input data symbol sub-streams and, producing a plurality of input data/training symbol sub-streams, said plurality of input data symbol sub-streams being derived from said input data symbol stream;

b) a transmitter Singular Value Decomposition (SVD) unit for providing a transmit weight matrix corresponding to said sub-carrier at a beginning of each super-frame in said plurality of super-frames; and

,

c) a transmitter weighting unit connected to said subspace training unit and said transmitter SVD unit for weighting said plurality of input data/training symbol sub-streams with said transmit weight matrix for distributing said plurality of input data/training symbol sub-streams along said plurality of spatial-subspace channels and providing transmit-weighted spatial-subspace data;

and said receiver further comprises;

d) a receiver SVD unit connected for providing a receive weight matrix corresponding to said sub-carrier and an initial estimate of a corresponding singular value matrix at a beginning of each super-frame of said plurality of super-frames;

e) a receiver weighting unit connected to said receiver SVD unit for receiving received spatial-subspace data related to said transmit-weighted spatial-subspace data and weighting said received spatial-subspace data with said receive weight matrix for providing receive-weighted spatial-subspace data, said receive-weighted spatial-subspace data containing received subspace training symbols;

f) a receiver link adaptation unit connected to said receiver weighting unit and said receiver SVD unit for receiving said initial estimate of said corresponding singular value matrix and processing said received subspace training symbols for periodically providing updated estimates of said corresponding singular value matrix during each super-frame of said plurality of super-frames; and

,

g) a data estimation unit connected to said receiver weighting unit and said receiver link adaptation unit for receiving said receive-weighted spatial-subspace data, said initial estimate of said corresponding singular value matrix and said updated estimates of said corresponding singular value matrix and providing said estimated output data during each super-frame of said plurality of super-frames,

wherein said receiver is configured to periodically process said sub-space training symbols during each super-frame of said plurality of super-frames for estimating output data related to said input data symbol stream, said receiver SVD unit is further configured to calculate an approximation of said receive weight matrix and an approximation of said initial estimate of said corresponding singular value matrix from a channel matrix corresponding to said sub-carrier by applying a partial SVD algorithm in which said receiver SVD unit is configured to truncate interim versions of said receive weight matrix and said initial estimate of said corresponding singular value matrix, and said receiver SVD unit is configured to performs said partial SVD algorithm by performing n1 iterations of an iterative SVD algorithm on said channel matrix to obtain and interim singular value matrix Λ

_k′ and

interim weight matrices U_k′ and

V_k′

, a complex conjugate transpose of said interim weight matrix U_k′

being said interim version of said receive weight matrix and said interim singular value matrix Λ

_k′

being said interim version of said initial estimate of said corresponding singular value matrix, and wherein said receiver SVD unit is further configured to determine a number p of said plurality of spatial-substance channels and truncates and zero-pads said interim matrices Λ

_k′

, U_k′ and

V_k′

to obtain matrices Λ

_k″

, U_k″

, and V_k″

, where n1 and p are positive integers.

35. The communication system of claim 34, wherein said receiver SVD unit is further configured to performs n2 iterations of said iterative SVD algorithm on said truncated matrices Λ

_k″

, U_k″

, and V_k″

to obtain said approximation of said initial estimate of said corresponding singular value matrix Λ

_kand said approximation of said receive weight matrix, where n2 is a positive integer.

36. The communication system of claim 35, wherein said receiver SVD unit is further configured to apply the partial SVD algorithm to said approximation of said initial estimate of said corresponding singular value matrix Λ

_k.

37. A method for transmitting an input data symbol stream over a plurality of spatial-subspace channels of a sub-carrier between a transmitter and a receiver, said input data symbol stream being partitioned into a plurality of super-frames, wherein at the transmitter said method comprises:

a) inserting subspace training symbols into a plurality of input data symbol sub-streams and producing a plurality of input data/training symbol sub-streams, said plurality of input data symbol sub-streams being derived from said input data symbol stream;

b) providing a transmit weight matrix corresponding to said sub-carrier at a beginning of each super-frame in said plurality of super-frames; and

,

c) weighting said plurality of input data/training symbol sub-streams with said transmit weight matrix for distributing said plurality of input data/training symbol sub-streams along said plurality of spatial-subspace channels and providing transmit-weighted spatial-subspace data;

wherein, said receiver is configured to periodically process said sub-space training symbols during each super-frame of said plurality of super-frames for estimating output data related to said input data symbol stream and at the receiver said method further comprises;

d) providing a receive weight matrix corresponding to said sub-carrier and an initial estimate of a corresponding singular value matrix at a beginning of each super-frame of said plurality of super-frames;

e) receiving received spatial-subspace data related to said transmit-weighted spatial-subspace data and weighting said received spatial-subspace data with said receive weight matrix for providing receive-weighted spatial-subspace data, said receive-weighted spatial-subspace data containing received subspace training symbols;

f) periodically providing undated estimates of said corresponding singular value matrix by processing said received subspace training symbols during each super-frame of said plurality of super-frames; and

,

g) providing said estimated output data by processing said receive-weighted spatial-subspace data using said initial estimate of said corresponding singular value matrix and said undated estimates of said corresponding singular value matrix during each super-frame of said plurality of super-frames,

wherein step (a) further comprises processing said plurality of input data symbol sub-streams for providing at least one of;

     1) at least one uncoded data symbol sub-stream for allocation on a corresponding at least one uncoded spatial-subspace channel and

     2) at least one pair of coded data symbol sub-streams for allocation on a corresponding at least one pair of coded spatial-subspace channels; and

wherein said plurality of spatial-subspace channels comprise only uncoded spatial-subspace channels and step (g) comprises performing a successive interference cancellation method for providing said estimated output data by detecting receive-weighted data symbols on one of said uncoded spatial-subspace channels, subtracting the detected receive-weighted data symbols from the receive-weighted spatial-subspace data and processing remaining uncoded spatial-subspace channels in a similar fashion wherein the uncoded spatial-subspace channels are processed in order of decreasing signal to noise plus interference ratio.

38. A method for transmitting an input data symbol stream over a plurality of spatial-subspace channels of a sub-carrier between a transmitter and a receiver, said input data symbol stream being partitioned into a plurality of super-frames, wherein at the transmitter said method comprises:

a) inserting subspace training symbols into a plurality of input data symbol sub-streams and producing a plurality of input data/training symbol sub-streams, said plurality of input data symbol sub-streams being derived from said input data symbol stream;

b) providing a transmit weight matrix corresponding to said sub-carrier at a beginning of each super-frame in said plurality of super-frames; and

,

c) weighting said plurality of input data/training symbol sub-streams with said transmit weight matrix for distributing said plurality of input data/training symbol sub-streams along said plurality of spatial-subspace channels and providing transmit-weighted spatial-subspace data;

wherein, said receiver is configured to periodically process said sub-space training symbols during each super-frame of said plurality of super-frames for estimating output data related to said input data symbol stream and at the receiver said method further comprises;

d) providing a receive weight matrix corresponding to said sub-carrier and an initial estimate of a corresponding singular value matrix at a beginning of each super-frame of said plurality of super-frames;

e) receiving received spatial-subspace data related to said transmit-weighted spatial-subspace data and weighting said received spatial-subspace data with said receive weight matrix for providing receive-weighted spatial-subspace data, said receive-weighted spatial-subspace data containing received subspace training symbols;

f) periodically providing undated estimates of said corresponding singular value matrix by processing said received subspace training symbols during each super-frame of said plurality of super-frames; and

,

g) providing said estimated output data by processing said receive-weighted spatial-subspace data using said initial estimate of said corresponding singular value matrix and said undated estimates of said corresponding singular value matrix during each super-frame of said plurality of super-frames.

wherein step (a) further comprises processing said plurality of input data symbol sub-streams for providing at least one of;

     1) at least one uncoded data symbol sub-stream for allocation on a corresponding at least one uncoded spatial-subspace channel and

     2) at least one pair of coded data symbol sub-streams for allocation on a corresponding at least one pair of coded spatial-subspace channels; and

wherein said plurality of spatial-subspace channels comprise coded spatial-subspace channels and uncoded spatial-subspace channels and step (g) comprises performing an iterative decoding/detection method on the receive-weighted spatial-subspace data for providing said estimated output data, with one iteration of said decoding/detection method comprising;

     1) decoding and detecting of receive-weighted coded data symbols transmitted on said coded spatial-subspace channels and replacing said receive-weighted coded data symbols in said receive-weighted spatial-subspace data with detected coded data symbols; and

,

     2) estimating and detecting receive-weighted uncoded data symbols transmitted on said uncoded spatial-subspace channels.

39. Method for transmitting an input data symbol stream over a plurality of spatial-subspace channels of a sub-carrier between a transmitter and a receiver, said input data symbol stream being partitioned into a plurality of super-frames, wherein at the transmitter said method comprises:

a) inserting subspace training symbols into a plurality of input data symbol sub-streams and producing a plurality of input data/training symbol sub-streams, said plurality of input data symbol sub-streams being derived from said input data symbol stream;

b) providing a transmit weight matrix corresponding to said sub-carrier at a beginning of each super-frame in said plurality of super-frames; and

,

c) weighting said plurality of input data/training symbol sub-streams with said transmit weight matrix for distributing said plurality of input data/training symbol sub-streams along said plurality of spatial-subspace channels and providing transmit-weighted spatial-subspace data;

wherein said receiver is configured to periodically process said sub-space training symbols during each super-frame of said plurality of super-frames for estimating output data related to said input data symbol stream, step (b) comprises calculating an approximation of said transmit weight matrix from a channel matrix corresponding to said sub-carrier by applying a partial Singular Value Decomposition (SVD) algorithm which comprises truncating an interim version of said transmit weight matrix, and applying said partial SVD algorithm comprises performing n1 iterations of an iterative SVD algorithm on said channel matrix to obtain an interim singular value matrix Λ

_k′ and

interim weight matrices U_k′ and

V_k′

, said interim weight matrix V_k′

being said interim version of said transmit weight matrix, wherein applying said partial SVD algorithm further comprises determining a number p of said plurality of spatial-subspace channels, and truncating and zero-padding said interim matrices Λ

_k′

, U_k′ and

V_k′

to obtain truncated matrices Λ

_k″

, U_k″ and

V_k″

, where n1 and p are positive integers.

40. The method of claim 39, wherein applying said partial SVD algorithm further comprises performing n2 iterations of said iterative SVD algorithm on said truncated matrices U_k″

, Λ

_k″ and

V_k″

to obtain an approximate singular value matrix Λ

_k and said approximation of said transmit weight matrix, where n2 is a positive integer.

41. A method for transmitting an input data symbol stream over a plurality of spatial-subspace channels of a sub-carrier between a transmitter and a receiver, said input data symbol stream being partitioned into a plurality of super-frames, wherein at the transmitter said method comprises:

a) inserting subspace training symbols into a plurality of input data symbol sub-streams and producing a plurality of input data/training symbol sub-streams, said plurality of input data symbol sub-streams being derived from said input data symbol stream;

b) providing a transmit weight matrix corresponding to said sub-carrier at a beginning of each super-frame in said plurality of super-frames; and

,

c) weighting said plurality of input data/training symbol sub-streams with said transmit weight matrix for distributing said plurality of input data/training symbol sub-streams along said plurality of spatial-subspace channels and providing transmit-weighted spatial-subspace data;

wherein, said receiver is configured to periodically process said sub-space training symbols during each super-frame of said plurality of super-frames for estimating output data related to said input data symbol stream, and at the receiver, said method further comprises;

d) providing a receive weight matrix corresponding to said sub-carrier and an initial estimate of a corresponding singular value matrix at a beginning of each super-frame of said plurality of super-frames;

e) receiving received spatial-subspace data related to said transmit-weighted spatial-subspace data and weighting said received spatial-subspace data with said receive weight matrix for providing receive-weighted spatial-subspace data, said receive-weighted spatial-subspace data containing received subspace training symbols;

f) periodically providing updated estimates of said corresponding singular value matrix by processing said received subspace training symbols during each super-frame of said plurality of super-frames; and

,

g) providing said estimated output data by processing said receive-weighted spatial-subspace data using said initial estimate of said corresponding singular value matrix and said updated estimates of said corresponding singular value matrix during each super-frame of said plurality of super-frames,

wherein step (d) comprises calculating an approximation of said receive weight matrix and an approximation of said initial estimate of said corresponding singular value matrix from a channel matrix corresponding to said sub-carrier by applying a partial SVD algorithm which comprises truncating an interim version of said receive weight matrix and said initial estimate of said corresponding singular value matrix, and applying said partial SVD algorithm comprises performing n1 iterations of an iterative SVD algorithm on said channel matrix to obtain an interim singular value matrix Λ

_k′ and

interim weight matrices U_k′ and

V_k′

, a complex conjugate transpose of said interim weight matrix U_k′

being said interim version of said receive weight matrix and said interim singular value matrix Λ

_k′

being said interim version of said initial estimate of said corresponding singular value matrix, wherein applying said partial SVD algorithm further comprises determining a number p of said plurality of spatial-subspace channels and truncating and zero-padding said interim matrices Λ

_k′

, U_k′ and

V_k′

to obtain truncated matrices Λ

_k″

, U_k″ and

V_k″

, where n1 and p are positive integers.

42. The method of claim 41, wherein applying said partial SVD algorithm further comprises performing n2 iterations of said iterative SVD algorithm on said truncated matrices Λ

_k″

, U_k″ and

V_k″

to obtain an approximation of said initial estimate of said corresponding singular value matrix Λ

_k and said approximation of said receive weight matrix, where n2 is a positive integer.