Abstract: This paper examines the Bit Error Rate (BER) performance of Multi-user Direct Sequence Multi-Carrier Code Division Multiple Access (DS/MC-CDMA) using spreading codes in fading channels. Multi-Carrier Code Division Multiple Access (MC-CDMA) system operating over frequency selective, slowly fading channels is considered and its performance is studied analytically and by computer simulations. We consider the downlink of a cellular radio system where for each user a BPSK modulation is used. The spreading codes are arranged in a way that reduces the effect of the multipath fading channel and restores some of the orthogonality losses between users. The obtained results show considerable performance improvement compared to conventional OFDM and to MC-CDMA that uses single spreading codes. Moreover, the spreading codes chosen by the method are in a consistent sequence. Using this code selection method, the system capacity of MU-MC-CDMA can be effectively increased without increasing too much system complexity. Simulation results show that the presented method can work well for fading channels.
Keywords: BPSK, DS/MC-CDMA, Walsh codes, Gold codes, PN Sequence.
Title: BER PERFORMANCE OF MULTI-USER MC-DS-CDMA USING SPREADING CODES IN FADING CHANNELS
Author: TATA BALAJI, J.RAVINDRABABU
International Journal of Electrical and Electronics Research
ISSN 2348-6988 (online)
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