An Efficient Algorithm Assisted Minimum Bit Error Rate Multiuser Detector for DS-CDMA Systems in Time-Varying and Frequency-Selective Fading Channels

Zeybek M., ERTUĞ Ö.

4th International Congress on Ultra Modern Telecommunications and Control Systems (ICUMT), St Petersburg, Rusya, 3 - 05 Ekim 2012, ss.154-161 identifier identifier

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Cilt numarası:
  • Doi Numarası: 10.1109/icumt.2012.6459656
  • Basıldığı Şehir: St Petersburg
  • Basıldığı Ülke: Rusya
  • Sayfa Sayıları: ss.154-161
  • Gazi Üniversitesi Adresli: Evet

Özet

A minimum bit error rate (MBER) multiuscr detector (MUD) is considered for Direct-Sequence Code-Division Multiple-Access (DS-CDMA) communication systems with time-varying and frequency-selective fading channels. The BER cost function of the proposed MBER MUD is highly non-linear and may have several local minimum. It is shown that with some appropriate constraints the BER cost function of the MBER MUD is equivalent to a constrained optimization problem which has a unique global minimum in the feasible region. An efficient Newton method with a barrier parameter is developed for finding the coefficients of the proposed MBER MUD. The BER performance of the MBER MUD is compared to decorrelating (DEC) detector, linear minimum mean-square error (LMMSE) detector, and the maximum likelihood detector for time varying and Rayleigh distributed frequency-selective fading DS-CDMA channels. Monte-Carlo simulations show that the BER of the MBER MUD can be significantly lower than that of the DEC and the LMMSE multiuser detectors.