Block-iterative GDFE (BI-GDFE) for CP-CDMA and MC-CDMA

A low-complexity block-iterative generalized decision feedback equalizer (BI-GDFE) receiver is proposed for CP-CDMA and MC-CDMA to iteratively and simultaneously (but not jointly) detect the multiuser signals. It utilizes the previously-made decisions to cancel out both multiple access interference (MAI) and inter-symbol interference (ISI) and to estimate the transmitted symbols by maximizing the output signal-to-interference-plus-noise ratio (SINR). We decouple the long spreading codes from the channel matrix, thus the key components of the equalizers are two one-tap filters, which are determined by the physical channel knowledge. Computer simulations have shown that single user near-MFB performance is attainable for rich multipath environment using the proposed receiver within several iterations.