Date Added: Aug 2009
Bit Error Rate (BER) performance of Multi-code Direct-Sequence Code Division Multiple Access (DS-CDMA) in a frequency-selective channel severely degrades due to strong Inter-Chip Interference (ICI). Frequency-Domain Equalization (FDE) based on the Minimum Mean Square Error (MMSE) criterion can take advantage of the channel frequency-selectivity and significantly improve the BER performance. However, the performance improvement is limited by the residual ICI which is present after MMSE-FDE. In this paper, the authors apply a joint transmit/receive MMSE-FDE (called double MMSE-FDE in this paper) for multi-code DS-CDMA signal transmissions to further improve the BER performance.