Performance of multi-code CDMA in a multipath fading channel

The authors provide a general investigation on the performance of multi-code code division multiple access (MC-CDMA) over Rayleigh fading plus additive white Gaussian noise (AWGN) channels. In MC-CDMA, high speed data sources are serial-to-parallel converted to low speed streams, which are further spread by Hadamard-Walsh orthogonal sequences and random codes. Numerical results show that, in a multipath fading channel, MC-CDMA with properly assigned Hadamard-Walsh sequences outperforms conventional CDMA when the signal to noise ratio (SNR) is low and shows comparable performance at high SNR. Furthermore, for the AWGN channel, the approximate formula developed by Lee et al. (see Proceedings of IEEE PIMRC'97, San Diego, p. 297-301, 1997) shows more variation than the authors' formula. The new approach is capable of telling the impact of code cross-correlation on system performance while the earlier approach does not.

[1]  M. Pursley,et al.  Analysis of Direct-Sequence Spread-Spectrum Multiple-Access Communication Over Rician Fading Channels , 1979, IEEE Trans. Commun..

[2]  Michael B. Pursley,et al.  Spread-Spectrum Multiple-Access Communications , 1981 .

[3]  John G. Proakis,et al.  Digital Communications , 1983 .

[4]  I Chih-Lin,et al.  Performance of multi-code CDMA wireless personal communications networks , 1995, 1995 IEEE 45th Vehicular Technology Conference. Countdown to the Wireless Twenty-First Century.

[5]  Mamoru Sawahashi,et al.  Wideband coherent DS-CDMA , 1995, 1995 IEEE 45th Vehicular Technology Conference. Countdown to the Wireless Twenty-First Century.

[6]  I Chih-Lin,et al.  Multi-code CDMA wireless personal communications networks , 1995, Proceedings IEEE International Conference on Communications ICC '95.

[7]  Roger L. Peterson,et al.  Introduction to Spread Spectrum Communications , 1995 .

[8]  Zhao Liu,et al.  Interference issues in multi-code CDMA networks , 1996, Proceedings of PIMRC '96 - 7th International Symposium on Personal, Indoor, and Mobile Communications.

[9]  Zhao Liu,et al.  A demand-assignment access control for multi-code DS-CDMA wireless packet (ATM) networks , 1996, Proceedings of IEEE INFOCOM '96. Conference on Computer Communications.

[10]  Zhao Liu,et al.  Channel access and interference issues in multi-code DS-CDMA wireless packet (ATM) networks , 1996, Wirel. Networks.

[11]  Masao Nakagawa,et al.  Performance of orthogonal multicarrier CDMA in a multipath fading channel , 1994, IEEE Trans. Commun..

[12]  H. Elders-Boll,et al.  Multi-code CDMA with variable sequence-sets , 1997, Proceedings of ICUPC 97 - 6th International Conference on Universal Personal Communications.

[13]  Dan Keun Sung,et al.  Capacity calculation in DS-CDMA systems supporting multi-class services , 1997, Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97.

[14]  H. Elders-Boll,et al.  Adaptive multi-rate multi-code CDMA systems , 1998, VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151).

[15]  Leif Wilhelmsson,et al.  Analysis of MFSK frequency-hopped spread-spectrum multiple-access over a Rayleigh fading channel , 1998, IEEE Trans. Commun..

[16]  Seung Young Park,et al.  Performance of Multi-Carrier Parallel Combinatory DS-CDMA System , 1998 .

[17]  Kiyomichi Araki,et al.  A Variable Length Code Transmission Technique on Multicode DS/SS Systems , 1998 .