Patent ID: 7027536

Claim:
A receiver operating in an environment where a transmission channel, H, between a transmitter of information and said receiver has a memory corresponding to n transmitted symbols, said receiver being responsive to an n o plurality of receiving antennas comprising: a pre-filter having an n o ×n i plurality of FIR filters, F(j,k), where n i is a number of transmitting antennas whose signals said receiver is processing, j is an index running from 1 to n o and k is an index running from 1 to n i , each filter F(j,k) being responsive to a signal that is derived from receiving antenna j, and applying its output signal to a pre-filter output point k; decision logic responsive to said pre-filter output points; and a sampling circuit interposed between said n o plurality of antennas and said pre-filter that samples received signal at rate T s = T l , where l is an integer that is greater than 1, and T is symbol rate of a transmitter whose signals said receiver receives, where said plurality of FIR filters is expressed by matrix W, and W is computed by W opt *={tilde over (B)} opt *R xy R yy −1 , W opt *={overscore (B)} opt *R xx H*(HR xx H*+R nn ) −1 , or W opt *={overscore (B)} opt *(R xx −1 +H*R mm −1 H) −1 H*R nn −1 , where R xx is an autocorrelation matrix of a block of signals transmitted by a plurality of transmitting antennas to said n 0 antennas via a channel having a transfer characteristic H, W opt is the optimum channel-shortening pre-filter, R nn is an autocorrelation matrix of noise received by said plurality of n o antennas during said block of signals transmitted by said transmitting antennas, R xy =R xx H*, R yy =HR xx *+R nn , are correlation matrices and {tilde over (B)} opt *, is a sub-matrix of matrix B opt *, where B opt =argmin B trace(R ee ) subject to a selected constraint, R ee being the error autocorrelation function.