Smart Antennas for Multi-Rate MC-CDMA Communication Systems

This paper proposes and compares three multi- rate receiver structures with post-fast Fourier transform (FFT) type and the pre-FFT type for orthogonal frequency division multiplexing code-division multiple access (OFDM-CDMA) communication systems. In multipath fading channel, the transmitted signal suffers from the effects of inter-chip interference (ICI) and multiple access interference (MAI). In order to solve these problems and support multimedia traffic, we propose three multi- rate methodologies- variable processing gain (VPG), variable chip rate (VCR) and multi-code systems to investigate the performance of the OFDM-CDMA communications in multipath fading environments. Simulations confirm the good performance of the proposed receiver structures.