Impact of Timing Offset on DS-CDMA with Overlap FDE

Direct sequence code division multiple access (DSCDMA) using frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion has been attracting much attention as a promising wireless access technique in a frequency-selective fading channel. The conventional FDE requires the insertion of guard interval (GI) to avoid the inter-block interference (IBI). However, GI insertion reduces the throughput. Recently, overlap FDE that requires no GI insertion was proposed. In a previous paper, we assumed ideal sampling timing. The presence of timing offset produces the inter-symbol interference (ISI) and thus degrades the transmission performance. In this paper, we evaluate the impact of timing offset on the transmission performance of DS-CDMA with overlap FDE by computer simulation.