Multiuser detection (MUD) is a key technique for combating multiple access interference (MAI) in CDMA systems. In this paper, we propose a simple and effective multiuser receiver, which we shall refer to as the objective function based multiuser detector (OFMUD). This is a successive multistage joint detector based on the statistical optimization of an objective function. Two objective functions will be considered in this paper. The first one is based on a maximum likelihood solution, and the second one is based on the least squared error solution. A key feature of the proposed detector is that among all the K user bits, we update the estimate of one and only one bit (the one that is most likely to be wrong) in every stage. Analytical and numerical results will show that significant performance improvement can be achieved compared with the conventional DS/CDMA receiver. At the same time, the near-far problem is alleviated. In addition, it is shown that the proposed receiver can outperform the popular multiuser parallel interference cancellation receiver in most cases with a smaller computational cost.
- Interference cancellation
- Multiple access interference
- Multiuser detection
- Wireless communications
ASJC Scopus subject areas
- Computer Networks and Communications
- Electrical and Electronic Engineering