Partial multiuser detection for CS-CDMA/CP over multipath channels and its comparison with DS-CDMA

  • Authors:

  • Li Yue;Nalin S. Weerasinghe;Chenggao Han;Takeshi Hashimoto

  • Affiliations:

  • Dept. of Electronics Eng., University of Electro-Communications, Chofushi, Tokyo, Japan;Dept. of Electronics Eng., University of Electro-Communications, Chofushi, Tokyo, Japan;Dept. of Electronics Eng., University of Electro-Communications, Chofushi, Tokyo, Japan;Dept. of Electronics Eng., University of Electro-Communications, Chofushi, Tokyo, Japan

  • Venue:
  • ICC'09 Proceedings of the 2009 IEEE international conference on Communications
  • Year:
  • 2009

Quantified Score

Hi-index 0.01

Visualization

Abstract

Convolutional spreading CDMA with cyclic prefix (CS-CDMA/CP) enables multiuser interference-free (MUI-free) transmission over multipath downlink channels with the use of zero correlation zone (ZCZ) codes. However, MUI-free transmission is guaranteed only when the data length D, channel delay L, and ZCZ length Z satisfy Z + 1 ≥ D + L, and the user population is constraint to be K ≤ ⌊N/Z+1⌋, where N is the code length. In this paper, for the purpose of allowing higher bandwidth efficiency for more active users, we propose an iterative partial multiuser detector for CS-CDMA/CP with M-ZCZ code to allow Z + 1 D + L. Because the detector is implemented in the symbol-level (after despreading) and only a partion of users are jointly considered, its receiver complexity is expected to be acceptable for a mobile terminal. Comparison with the DS-CDMA system employing chip-equalization receiver shows that the CS-CDMA/CP system employing the proposed receiver offers a better tradeoff between the performance and receiver complexity, which indicates its potential application in future wireless communications.