Patent ID: 6714607
Filing Date: 2004-03-30
Classification: H04B,H04L

Abstract:
A method comprising:joint demodulating a desired signal and one or more interfering signals with a Viterbi equalizer having an adaptive total number of states based on channel impulse response (CIR) coefficients associated with the desired signal and the one or more interfering signals; determining a first cross-correlation function between a received signal and an embedded training sequence of the desired signal; determining a first time value of a peak in the first cross-correlation function; determining a second cross-correlation function between the received signal and an embedded training sequence of an interfering signal of the one or more interfering signals; determining a second time value of a peak in the second cross-correlation function; determining a time difference between the first time value and the second time value; and estimating a plurality of CIR coefficients associated with the interfering signal based on the time difference; wherein said estimating comprises: if the time difference is greater than zero, offsetting the CIR coefficients associated with the interfering signal by int((1+td)/4) samples in a first direction relative to CIR coefficients associated with the desired signal; and if the time difference is less than zero, offsetting the CIR coefficients associated with the interfering signal by int((1âˆ’td)/4) samples in a second direction relative to the CIR coefficients associated with the desired signal, the second direction opposite the first direction; wherein int ( ) represents an integer function, and td represents the time difference as an integral number of quarter symbol periods.