The combination of macrodiversity reception with maximum likelihood (ML) multiuser detection has the capability to reduce the bit error rate (BER) for many users by several orders of magnitude compared with multiuser detectors that operate on each antenna separately [1]. In this paper, we present the Conditional Metric Merge (CMM) algorithm which reduces the computational complexity of the ML m...

Introduction: In the recent decade, there have been significant efforts in developing multiuser detection technologies to alleviate the effect of multiple access interference (MAI) in codedivision multiple-access (CDMA) systems. Blind multiuser detection is of special interest for MAI mitigation in CDMA systems since it is impractical to assume perfect knowledge of parameters such as spreading ...

The bit error rate of a coded Multiuser OFDM (M-OFDM) system and coded Multicarrier CDMA (MC-CDMA) system with multiuser detection is analyzed. The paper focuses on downlink wireless applications, where the channel suffers from frequency-selective fading. We investigate both systems when long time interleaving is possible, though introducing large delays, and when time interleaving is limited. ...

Optimal multiuser detection of trellis coded signals has prohibitive complexity. A suboptimal concatenated scheme consisting of a maximum a posteriori (MAP) multiuser interference (MUI) detector followed by a deinterleaver and a soft trellis decoder has recently received considerable attention in the literature [1]. We call this scheme Concatenated Multiuser Detector and Trellis Decoder (CMDTD)...

We consider the problem of turbo multiuser detection for synchronous and asynchronous code-division multiple-access (CDMA) in the presence of unknown users. Turbo multiuser detectors, as previously developed, typically require knowledge of the signature waveforms of all of the users in the system and ignore users whose signature sequences are unknown, e.g., users outside the cell. In this paper...

In recent years, future generation wireless communication technologies are most the prominent fields in which many innovative techniques are used for effective communication. Orthogonal frequency-division multiplexing is one of the important technologies used for communication in future generation technologies. Although it gives efficient results, it has some problems during the implementation ...