Downlink and Uplink MC-DS-CDMA Sensitivity to Timing Jitter

In this contribution, we consider the effect of timing jitter on the performance of the multicarrier direct-sequence CDMA (MCDS-CDMA) system and compare the results for uplink and downlink transmission, assuming orthogonal spreading sequences. Theoretical expressions are derived for the performance degradation caused by the timing jitter, in the presence of a multipath channel. Assuming an AWGN channel, perfect power control and full load, it is shown that the performance degradation is independent of the number of carriers, the spreading factor and the spectral contents of the jitter, but only depend on the jitter variance. Further, we point out that, if the jitter spectrum is the same for all users, the degradation is the same for the downlink and the uplink.