Multi-rate schemes in DS/CDMA systems

Different modulation schemes supporting multiple data rates in a direct sequence code division multiple access (DS/CDMA) system are studied, focusing on how to support personal communication services. 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.

[1]  Laurence B. Milstein,et al.  Comparison of hybrid FDMA/CDMA systems in frequency selective Rayleigh fading , 1994, IEEE J. Sel. Areas Commun..

[2]  Nobukazu Doi,et al.  DS/CDMA prototype system transmitting low bit-rate voice and high bit-rate ISDN signals , 1994, Proceedings of IEEE Vehicular Technology Conference (VTC).

[3]  M. Pursley,et al.  Performance Evaluation for Phase-Coded Spread-Spectrum Multiple-Access Communication - Part I: System Analysis , 1977, IEEE Transactions on Communications.

[4]  Jinkang Zhu,et al.  Properties and Application of Parallel Combinatory SS Communication System , 1992, IEEE Second International Symposium on Spread Spectrum Techniques and Applications.

[5]  Randy H. Katz,et al.  Adaptation and mobility in wireless information systems , 2002, IEEE Communications Magazine.

[6]  Arne Svensson,et al.  Multi-Rate Performance in DS/CDMA Systems , 1995 .

[7]  Takaaki Hasegawa,et al.  Spread spectrum pulse position modulation-a simple approach for Shannon's limit- , 1992, [Proceedings] Singapore ICCS/ISITA `92.

[8]  Arne Svensson,et al.  Successive interference cancellation in multiple data rate DS/CDMA systems , 1995, 1995 IEEE 45th Vehicular Technology Conference. Countdown to the Wireless Twenty-First Century.

[9]  Uwe-Carsten Fiebig,et al.  Design study for a CDMA-based third-generation mobile radio system , 1994, IEEE J. Sel. Areas Commun..

[10]  E. A. Geraniotis,et al.  Error Probability for Direct-Sequence Spread-Spectrum Multiple-Access Communications - Part II: Approximations , 1982, IEEE Transactions on Communications.