Performance of transmitter preprocessing assisted multi-carrier IDMA in frequency-selective channel for downlink communications

Abstract

In this correspondence, we investigate and study the performance of multi-user transmitter preprocessing (MUTP) aided multi-carrier interleave division multiple access (MC-IDMA) systems in frequency-selective channels under perfect and imperfect channel state information (CSI) at the transmitter. The MUTP considered in this correspondence creates an orthogonal subspace to the interfering subspace that results in the complete elimination of multi-user interference (MUI) in the context of downlink (DL) communications. Further, this MUTP approach is compared with the conventional zero-forcing (ZF) MUTP and eigen based MUTP. Our simulation study shows that all the MUTP approaches results in the same performance in terms of achievable bit error rate (BER). Furthermore, MUTP aided MC-IDMA systems outperform MUTP aided MC-CDMA systems and MC-IDMA systems with multi-user detection (MUD).