Diversity receivers and methods for relatively-delayed signals

A method for processing a signal modulated with data symbols and received through a plurality of paths, the method comprising:

• sampling said signal to obtain at least one sample per data symbol time interval;
• determining a set of complex channel coefficients that characterize said delayed paths;
• computing an estimate of a current symbol and an associated metric, wherein said current symbol estimate and said associated metric are based on said sampling of said signal, said determining of said set of complex channel coefficients, estimates of previously estimated symbols and associated metrics, and hypotheses of not yet estimated symbols;
• storing said current computed symbol estimates and said associated metrics for combinations of said hypothesized symbols in a metric table for said current symbol;
• and
• generating a soft symbol value for a symbol based on said sampled signal, said determined set of channel coefficients and computed estimates of symbols.

A computer-readable medium having stored thereon instructions for decoding a signal modulated with data symbols and received via delayed paths, said instructions comprising code for performing the steps of:

• sampling said signal to obtain at least one sample per data symbol time interval;
• determining a set of complex channel coefficients that characterize said delayed paths;
• hypothesizing not yet estimated symbols;
• computing an estimate of a current symbol and an associated metric, wherein said current symbol estimate and said associated metric are based on said sampling, said determining of said set of complex channel coefficients, said hypothesizing of not yet estimated symbols, estimates of previously estimated symbols and associated metrics;
• storing said current computed symbol estimates and said associated metrics with combinations of said hypothesized symbols in a metric table for said current symbol;
• and
• generating a soft symbol value for a symbol based on said sampled signal, said determined set of channel coefficients, and computed estimates of symbols.

A method for performing equalization in a diversity receiver comprising:

• receiving an information signal along at least two different paths, one path having a time delay L relative to the other path;
• wherein said time delay L is a non-integer number of symbol periods, and a value of L is greater than 25 symbol periods;
• and
• generating a soft symbol value for a symbol in said information signal based on samples from said information signal, channel coefficients associated with said information signal and stored estimates associated with other symbols in said information signal,
• wherein a computational complexity associated with said step of generating is on the order of M, where M is a size of a symbol alphabet associated with said information signal.