METHOD AND SYSTEM FOR A 4X2 SFBC/STBC SYSTEM WITH 2 SPATIAL STREAMS USING ANGLE FEEDBACK
Aspects of a method and system for a 4×2 SFBC/STBC system with 2 spatial streams using angle feedback are presented. Aspects of the system include a 4×2 SFBC/STBC communication diversity system with 2 distinct spatial streams using angle feedback. A receiving station may concurrently receive signals. A channel estimate matrix may be computed based on the received signals. A rotation angle value may be computed based on the channel estimate matrix. The receiving station may transmit the computed rotation angle via feedback information to a transmitting station. The transmitting station may utilize the received feedback information to generate a plurality of 4 distinct transmit chain signals based on data symbols received via a plurality of 2 spatial streams. Each of the distinct transmit chain signals may comprise a plurality of codewords. The transmitting station may concurrently transmit the plurality of transmit chain signals via the plurality of transmitting antennas.
1 . A method for processing signals, the method comprising:
performing by one or more processors and/or circuits:
computing one or more channel estimate matrices based on a concurrently received plurality of signals;
computing a square matrix based on said computed one or more channel estimated matrices;
determining one or more distinct off-diagonal values in said computed square matrix;
selecting one or more rotation angle values based on a minimum condition, wherein said minimum condition is based on said determined one or more distinct off-diagonal values; and
transmitting a binary representation of said selected one or more rotation angle values as feedback information.
2 . The method according to claim 1 , comprising selecting said one or more rotation angle values from a plurality of candidate rotation angle values.
3 . The method according to claim 2 , comprising determining a number for said plurality of candidate rotation angle values based on a selected plurality of quantization bits.
4 . The method according to claim 3 , wherein said binary representation of said selected one or more rotation angle values is based on said selected plurality of quantization bits.
5 . The method according to claim 2 , comprising computing a sum of squared values among said one or more distinct off-diagonal values for each of said plurality of candidate rotation angle values.
6 . The method according to claim 5 , wherein said minimum condition corresponds to a minimum value among said computed plurality of sum of squared values.
7 . The method according to claim 1 , wherein said square matrix is computed based on a multiplication of said computed one or more channel estimate matrices and a Hermitian transformed version of said computed one or more channel estimate matrices.
8 . A system for processing signals, the system comprising:
one or more circuits that are operable to compute one or more channel estimate matrices based on a concurrently received plurality of signals;
said one or more circuits are operable to compute a square matrix based on said computed one or more channel estimated matrices;
said one or more circuits are operable to determine one or more distinct off-diagonal values in said computed square matrix;
said one or more circuits are operable to select one or more rotation angle values based on a minimum condition, wherein said minimum condition is based on said determined one or more distinct off-diagonal values; and
said one or more circuits are operable to transmit a binary representation of said selected one or more rotation angle values as feedback information.
9 . The system according to claim 8 , wherein said one or more circuits are operable to select said one or more rotation angle values from a plurality of candidate rotation angle values.
10 . The system according to claim 9 , wherein said one or more circuits are operable to determine a number for said plurality of candidate rotation angle values based on a selected plurality of quantization bits.
11 . The system according to claim 10 , wherein said binary representation of said selected one or more rotation angle values is based on said selected plurality of quantization bits.
12 . The system according to claim 9 , wherein said one or more circuits are operable to compute a sum of squared values among said one or more distinct off-diagonal values for each of said plurality of candidate rotation angle values.
13 . The system according to claim 12 , wherein said minimum condition corresponds to a minimum value among said computed plurality of sum of squared values.
14 . The system according to claim 8 , wherein said square matrix is computed based on a multiplication of said computed one or more channel estimate matrices and a Hermitian transformed version of said computed one or more channel estimate matrices.
15 . A system for processing signals, the system comprising:
one or more circuits that are operable to determine a rotation angle value based on received feedback information;
said one or more circuits are operable to compute a rotation factor value based on said determined rotation angle value;
said one or more circuits are operable to generate a plurality of transmit chain signals based on said computed rotation factor value and a plurality of data symbol values; and
said one or more circuits are operable to transmit said generated plurality of transmit chain signals.
16 . The system according to claim 15 , wherein said plurality of data symbol values are received via a plurality of spatial streams.
17 . The system according to claim 15 , wherein each of said generated plurality of transmit chain signals comprises a distinct plurality of codeword values.
18 . The system according to claim 17 , wherein said one or more circuits are operable to generate said distinct plurality of codeword values based on said computed rotation factor value and at least a portion of said plurality of data symbol values.
19 . The system according to claim 18 , wherein said portion of said plurality of data symbol values is received via a single spatial stream among a plurality of spatial streams.
20 . The system according to claim 15 , wherein said rotation factor is computed as an exponential function of said determined rotation angle value.