Multi-Rate Schemes in DS/CDMA Systems
نویسندگان
چکیده
Different modulation schemes supporting multiple data rates in a Direct Sequence Code Division Multiple Access (DS/CDMA) system are studied. Both AWGN and multipath Rayleigh fading channels are considered. It is shown that the multi processing-gain scheme and the multi-channel scheme have almost the same performance. However, the multi-channel scheme has some advantages due to near-far resistance, easier code design and easier multi-user receiver construction. The drawback though, is the need for linear amplifiers. A multi-modulation scheme is also possible, but the performance for the users with the high data rates is significantly worse than for the other schemes.
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