Delay-time/Code Division Multi-access for Uplink Transmission In A Frequency-selective Fading Channel
نویسندگان
چکیده
The downlink bit error rate (BER) performance of direct sequence-code division multi-access (DS-CDMA) in a frequency-selective fading channel can be significantly improved by the use of frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion. In the uplink case, however, the presence of multi-access interference (MAI) significantly degrades the BER performance even if MMSE-FDE is used. In this paper, we propose a new hybrid multi-access technique called delay-time/code division multi-access (DT/CDMA) for the uplink transmission, which can mitigate the MAI while achieving the frequency diversity gain, and evaluate the achievable BER performance by computer simulation. Keywords— Multi-access, delay-time domain, MMSE-FDE
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