Performance analysis of SNR degradation by IS-95 filter in CDMA1xEV-DV system

By design, IS-95 filter generates remaining ICI (interchip interference) after matched filtering in the receiver side. To keep the backward compatibility, IS-95 filter is recommended as a chip waveform shaping filter in all sequels of international standard from the 3GPP2. The performance degradation by the filter was not significant in a conventional QPSK modulation scheme but not negligible in the recently proposed system where multi-level modulation scheme is adopted. In this paper, we investigate the performance degradation caused by the ICI of the IS-95 filter and propose MMSE receiver filter to compensate for the performance loss. We apply the proposed receiver to CDMA1xEV-DV system where multi-level modulation is used.