초록 ▼

An iterative approach is used to find maximum likelihood sequence estimates of a transmitted symbol sequence. Each possible transmitted signal is represented by an indicator vector which selects the transmitted symbol from a symbol library vector. Channel estimates are generated representing the est

An iterative approach is used to find maximum likelihood sequence estimates of a transmitted symbol sequence. Each possible transmitted signal is represented by an indicator vector which selects the transmitted symbol from a symbol library vector. Channel estimates are generated representing the estimated impulse response of the communication channel to each transmitted symbol. The channel estimates are used to form a matched medium response vector and an interaction matrix. The matched medium response vector represents the matched medium response of the receiver to both a transmitter and the channel for each transmitted symbol. The interaction matrix represents the ISI between symbols. The matched medium response vector and the interaction matrix are fed to an estimated symbol probability vector generator which calculates in an iterative manner the estimated symbol probability vectors corresponding to each transmitted symbol. The estimated symbol probability vectors can be output to a hard-decision generator which makes a hard-decision about the transmitted symbols. Alternatively, the estimated symbol probability vectors can be output to a soft-decision decoder.

대표청구항 ▼

[ What is claimed is:] [1.] A method for demodulating a received signal corresponding to a transmitted symbol sequence having a plurality of symbols comprising the steps of:a) receiving the signal over a communication channel;b) forming a symbol library vector representing possible transmitted symbo

[ What is claimed is:] [1.] A method for demodulating a received signal corresponding to a transmitted symbol sequence having a plurality of symbols comprising the steps of:a) receiving the signal over a communication channel;b) forming a symbol library vector representing possible transmitted symbols in the transmitted symbol sequence;c) generating channel estimates representing the estimated impulse response of the communication channel to each transmitted symbol;d) forming a matched medium response vector based upon the received signal, the channel estimates, and the symbol library vector;e) forming an interaction matrix based upon the channel estimates and the symbol library vector; andf) forming an estimated symbol probability vector having a plurality of elements for selecting an estimate of each transmitted symbol in the transmitted symbol sequence, wherein the estimated symbol probability vector is formed by recursively estimating each element of each estimated symbol probability vector based upon the matched medium response vector, the interaction matrix, and a previous estimate of the estimated symbol probability vector for interfering symbols.