Improved successive cancellation of DS-CDMA signals using signal orthogonalization

In DS-CDMA communication systems, multiple access interference can be mitigated with multi-user receiver techniques. One such technique, successive cancellation, is limited in performance because cancelled signals are not entirely removed. An improvement to successive cancellation is proposed which employs orthogonalized signature sequences. This allows all cancelled signal energy to be removed. Alternatively, orthogonalized signature sequences can be used in the detection process, eliminating the need for the cancellation process. Simulation results demonstrate the improved performance of the proposed approach. Extensions of the approach for asynchronous signals, time-dispersed signals, and other forms of DS-CDMA are also discussed.

[1]  J. M. Holtzman,et al.  DS/CDMA successive interference cancellation , 1994, Proceedings of IEEE 3rd International Symposium on Spread Spectrum Techniques and Applications (ISSSTA'94).

[2]  P. Teder,et al.  CDMA-IC: A proposal for future high capacity digital cellular systems , 1993, IEEE 43rd Vehicular Technology Conference.

[3]  Alexandra Duel-Hallen,et al.  Decorrelating decision-feedback multiuser detector for synchronous code-division multiple-access channel , 1993, IEEE Trans. Commun..

[4]  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.

[5]  Zoran Zvonar,et al.  Multiuser detection for CDMA systems , 1995, IEEE Wirel. Commun..

[6]  M. Ewerbring,et al.  CDMA-IC: a novel code division multiple access scheme based on interference cancellation , 1992, [1992 Proceedings] The Third IEEE International Symposium on Personal, Indoor and Mobile Radio Communications.

[7]  Hideki Imai,et al.  Combination of an Adaptive Array Antenna and a Canceller of Interference for Direct-Sequence Spread-Spectrum Multiple-Access System , 1990, IEEE J. Sel. Areas Commun..

[8]  W. Brogan.  Modern Control Theory , 1971 .

[9]  S. T. Alexander,et al.  Adaptive Signal Processing: Theory and Applications , 1986 .

[10]  A. Svensson,et al.  Multi-stage interference cancellation in multi-rate DS/CDMA systems , 1995, Proceedings of 6th International Symposium on Personal, Indoor and Mobile Radio Communications.

[11]  Upamanyu Madhow,et al.  MMSE interference suppression for direct-sequence spread-spectrum CDMA , 1994, IEEE Trans. Commun..

[12]  Andrew J. Viterbi,et al.  Very Low Rate Convolutional Codes for Maximum Theoretical Performance of Spread-Spectrum Multiple-Access Channels , 1990, IEEE J. Sel. Areas Commun..

[13]  M.B. Pursley,et al.  Crosscorrelation properties of pseudorandom and related sequences , 1980, Proceedings of the IEEE.

[14]  J. M. Holtzman,et al.  Analysis of a DS/CDMA successive interference cancellation scheme using correlations , 1993, Proceedings of GLOBECOM '93. IEEE Global Telecommunications Conference.

[15]  S. Thomas Alexander,et al.  Adaptive Signal Processing , 1986, Texts and Monographs in Computer Science.

[16]  P. Teder,et al.  CDMA with interference cancellation: A technique for high capacity wireless systems , 1993, Proceedings of ICC '93 - IEEE International Conference on Communications.