1. A method of received signal processing, comprising: generating despread signal samples from received signal streams transmitted using different spreading codes; estimating channel response associated with the different received signal streams; generating a basis change matrix to provide transformation of the channel response estimate from a first lattice basis to a second lattice basis having greater orthogonality between decision regions than the first lattice basis; aligning the despread signal samples to the second lattice; generating combining weights based on the channel response estimate and a conjugate transpose of the inverse of the basis change matrix; generating symbol estimation decision statistics based on the combining weights and the aligned despread signal samples; and generating soft bit values for decoding based on the symbol estimation decision statistics.