Suppression of ISI Caused by Sampling Time Offset in IFDMA Systems

In this article, we investigate the influence of sampling time offset on the bit error rate (BER) performance in interleaved frequency-division multiple-access (IFDMA) uplink systems. It is shown that even small sampling time offset results in inter-symbol interference (ISI) and in signal-to-noise ratio (SNR) degradation. To avoid this, a soft ISI suppression algorithm is proposed which allows to significantly improve the system performance. The proposed algorithm can be applied to both IFDMA uplink systems and to conventional orthogonal frequency-division multiple-access (OFDMA) uplink systems.