Apparatus and method for improving the performance of a linear equalizer with multiple receive antennas

An apparatus for wireless communication, comprising:

• at least one processor configured to:
• estimate a channel impulse response (CIR) for each receiver chain of a diversity receiver;
• process a signal from each receiver chain using a respective automatic gain control (AGC) for each receiver gain;
• determine post-AGC noise power estimates for each receiver chain based on the CIRs and the processed signals;
• and
• adaptively adjust equalizer taps of each receiver chain based on the post-AGC noise power estimates, wherein to adaptively adjust the equalizer taps includes to compute the equalizer taps using an inversion of a received signal covariance matrix, wherein:
• the inversion of the received signal covariance matrix comprises adding a positive term to a diagonal of the received signal covariance matrix;
• the positive term is a product of a conditioning coefficient and a sum of the diagonal of the received signal covariance matrix;
• and
• the condition coefficient has a value that is greater than zero and less than or equal to 1.

An apparatus for initializing an equalizer in a diversity receiver, comprising:

• means for estimating a channel impulse response (CIR) for each receiver chain of the diversity receiver;
• means for processing a signal from each receiver chain using a respective automatic gain control (AGC) for each receiver chain;
• means for determining post-AGC noise power estimates for each receiver chain based on the CIRs and the processed signals;
• and
• means for adaptively adjusting equalizer taps of each receiver chain based on the post-AGC noise power estimates, wherein the adaptively adjusting the equalizer taps includes computing the equalizer taps using an inversion of a received signal covariance matrix, wherein:
• the inversion of the received signal covariance matrix comprises adding a positive term to a diagonal of the received signal covariance matrix;
• the positive term is a product of a conditioning coefficient and a sum of the diagonal of the received signal covariance matrix;
• and
• the condition coefficient has a value that is greater than zero and less than or equal to 1.

A non-transitory computer-readable medium comprising codes for:

• estimating a channel impulse response (CIR) for each receiver chain of a diversity receiver;
• processing a signal from each receiver chain using a respective automatic gain control (AGC) for each receiver chain;
• determining post-AGC noise power estimates for each receiver chain based on the CIRs and the processed signals;
• and
• adaptively adjusting equalizer taps of each receiver chain based on the post-AGC noise power estimates, wherein the adaptively adjusting the equalizer taps includes computing the equalizer taps using an inversion of a received signal covariance matrix, wherein:
• the inversion of the received signal covariance matrix comprises adding a positive term to a diagonal of the received signal covariance matrix;
• the positive term is a product of a conditioning coefficient and a sum of the diagonal of the received signal covariance matrix;
• and
• the condition coefficient has a value that is greater than zero and less than or equal to 1.