Self-Encoded Spread Spectrum and Turbo Coding

  • Jang, Won-Mee (Peter Kiewit Institute of Information Science, Technology & Engineering, Department of Computer and Electronics Engineering, University of Nebraska) ;
  • Nguyen, Lim (Peter Kiewit Institute of Information Science, Technology & Engineering, Department of Computer and Electronics Engineering, University of Nebraska) ;
  • Hempel, Michael (Peter Kiewit Institute of Information Science, Technology & Engineering, Department of Computer and Electronics Engineering, University of Nebraska)
  • Published : 2004.03.01

Abstract

Self-encoded multiple access (SEMA) is a unique realization of random spread spectrum. As the term implies, the spreading code is obtained from the random digital information source instead of the traditional pseudo noise (PN) code generators. The time-varying random codes can provide additional security in wireless communications. Multi-rate transmissions or multi-level grade of services are also easily implementable in SEMA. In this paper, we analyze the performance of SEMA in additive white Gaussian noise (AWGN) channels and Rayleigh fading channels. Differential encoding eliminates the BER effect of error propagations due to receiver detection errors. The performance of SEMA approaches the random spread spectrum discussed in literature at high signal to noise ratios. For performance improvement, we employ multiuser detection and Turbo coding. We consider a downlink synchronous system such as base station to mobile communication though the analysis can be extended to uplink communications.

Keywords

References

  1. T. F. Wong, T. M. Lok, and J. S. Lehnert, 'Asynchronous multiple access interference suppression and chip waveform selection with aperiodic ran-dom sequences,' IEEE Trans. Commun., vol. 47, no. 1, pp. 103-114, Jan. 1999 https://doi.org/10.1109/26.747817
  2. J. S. Lehnert and M. B. Pursley, 'Error probability for binary direct sequence spread spectrum communications with random signature sequences,' IEEE Trans. Commun., vol. COM-35, no. I, pp. 87-98. Jan. 1987
  3. E. Geraniotis and B. Ghaffari, 'Performance of binary and quaternary direct-sequence spread-spectrum multiple-access systems with random signature sequences,' IEEE Trans. Commun., vol. 39, no. 5, pp. 713-724, May 1991 https://doi.org/10.1109/26.87162
  4. M. Simon et al., Spread Spectrum Communications, vol. 1, p. 262, Com-puter Science Press, 1985
  5. L. Nguyen, 'Self-encoded spread spectrum and multiple access communications, in IEEE International Symposium on Spread Spectrum Techniques and Applications, Parsippany, NJ, Sept. 2000, pp. 394-398
  6. Y. Kong, L. Nguyen, and W. Jang, 'On the BER of selfencoded spread spectrum communication system,' in Proc. lASTED Int. Conf. Wireless and Optical Commun., Banff, Canada, June 27-29, 2001, pp. 202-206.
  7. Y. Kong, L. Nguyen, and W. M. Jang, 'Selfencoded spread spectrum modulation with differential encoding,' in IEEE International Symposium on Spread Spectrum Techniques and Applications, Sept. 2-5, 2002, pp. 471-474
  8. R. K. Morrow and J. S. Lehnert, 'Bit-to-hit error dependence in slotted DS/SSMA packet system with random signature sequences,' IEEE Trans. Commun., vol. 37, no. 10, pp. 1052-1061, Oct. 1989 https://doi.org/10.1109/26.41160
  9. S. Verdu, Multiuser Detection, pp. 72, 104-119, New York, Cambridge University Press, 1998
  10. B. VojCic and W. M. Jang, 'Transmitter precoding in synchronous mul-tiuser communications,' IEEE Trans. Commun., vol. 46, no. 10, pp. 1346-1355, Oct. 1998 https://doi.org/10.1109/26.725312
  11. R. Lupas and S. Verdu, 'Linear multiuser detectors for synchronous code-division multiple access channels,' IEEE Trans. Inform. Theory, vol. 35, no. 1, pp. 123-135, Jan. 1989 https://doi.org/10.1109/18.42183
  12. W. M. Jang, B. VojCic, and R. Pickholtz, 'Joint transmitter/receiver opti-mization in synchronous multiuser communications over multipath chan-nels,' IEEE Trans. Commun., vol. 46, no. 2, pp. 269-278, Feb. 1998 https://doi.org/10.1109/26.659485
  13. J. G. Proakis, Digital Communications, 4th ed., pp. 41-24, 272, 442, 824, McGraw-Hill, 2001
  14. W. M. Jang, L. Nguyen, and M. Hempel, 'Precoded random spreading multiple access system in AWGN channels,' accepted to IEEE Trans. Wireless Commun., 2003
  15. J. H. Jung, W. M. Jang, and L. Nguyen, 'Implementation of selfencoded spared spectrum multiple access with convolutional codes,' in Proc. lASTED Int. Conf. Wireless and Optical Commu., pp. 250-254, Banff, Canada, July 2002
  16. C. Berrou, A. Glavieux, and P. Thitimajshima, 'Near Shannon limit error-correcting coding and decoding: Turbo-codes,' in Proc. IEEE ICC'93, Geneva, Switzerland, 1993, pp. 1064-1070
  17. C. E. Shannon, 'A mathematical theory of communication,' Bell Syst. Tech. j., vol. 27, pp. 379-423, 623-656, July-Oct. 1948 https://doi.org/10.1002/j.1538-7305.1948.tb01338.x
  18. L. C. Perez, J. Seghers, and D. J. Costello, 'A distance spectrum interpre-tation of turbo codes,' IEEE Trans. Inform. Theory, vol. 42, no. 6, Part I, pp. 1698-1709, Nov. 1996 https://doi.org/10.1109/18.556666
  19. J. Seghers, 'On the free distance of TURBO codes and related product codes,' Final Rep., Diploma Project SS 1995, no. 6613, p. 14, Swiss Fed-eral Institute of Technology, Zurich, Switzerland, Aug. 1995
  20. S. Lin and D. J. Costello, Jr., Error Control Coding: Fundamentals and Applications, p. 325, Englewood Cliffs, NJ: Prentice-Hall, 1983
  21. A. Papoulis and S. U. Pillai, Probability, Random Variables, and Stochastic Processes, 4th ed., pp. 89-90, McGraw-Hill, 2002
  22. R. D. Gaudenzi, C. Elia, and R. Viola, 'Bandlimited quasi-synchronous CDMA: A novel satellite access techniques for mobile and personal com-munication Systems,' IEEE J. Select. Areas Commun., vol. 10, no. 2, pp. 328-342, Feb. 1992 https://doi.org/10.1109/49.126984