Semi-blind decorrelating multiuser detection for synchronous CDMA

Multiuser detection is a key technology for combating multiple access interference (MAI) in CDMA systems. In this paper, we propose three effective one-shot multiuser semi-blind decorrelating detectors based on least squares (LS), total least squares (TLS) and mixed LS/TLS (MLS) formulations. All of the proposed algorithms are based on the classic decorrelating detector and a new semi-blind signature matrix. Different assumptions regarding the noise in the proposed semi-blind signature matrix lead to different detection algorithms. We also find that the classic decorrelating detector can be regarded as a special case of the proposed LS decorrelating detector. The proposed detection algorithms are simple and direct, where only the timing, signature and amplitude of the desired user are required. In addition, no search or convergence procedure is required. Finally, theoretical analysis and computer simulations are presented to illustrate the performance of the proposed algorithms.