Multiple access interference (MAI) limits the capacity of Direct sequence Code Division Multiple Access (DS-CDMA) systems. In CDMA systems MAI is considered as additive noise and matched filter bank is employed. Traditionally, multiuser detectors a code matched and a multiuser linear filter are used which increases the complexity of the system due to its nature of operation. Multiuser detection...

Two promising classes of techniques are developed for e cient multiuser detection in codedivision multiple-access (CDMA) communication systems subject to fading due to time-varying multipath propagation. Both are designed to jointly suppress both intersymbol and multipleaccess interference inherent in such systems, and exploit all available time and frequency diversity. The rst is a family of l...

This article continues the discussion of multiuser detection. We first analyze the BER performance of a conventional detector. Starting with the results for 2 user case, we extend it the case of K users. We then define certain other performance measures which are simpler to calculate (than BER) and yet give a reasonable insight into the performance of multiuser detectors. Finally, we try to def...

Abstract The multiple-access interference (MAI) limits the performance of the DS-CDMA uplink transmission. 2D OVSF spread/chip-interleaved DS-CDMA is an MAI-free system, and hence single-user coherent frequency-domain equalization (FDE) can be used instead of complicated multiuser detection (MUD). However, coherent FDE needs channel estimation. Pilot-assisted channel estimation is not reliable ...

| This paper introduces a new multiuser detection algorithm based on a gradient guided search that can achieve near-optimum performance while its implementation complexity is linear in the number of users. The new algorithm attempts to perform jointly optimum multiuser detection by updating one user's bit decision each iteration in the best possible way. When a decorrelating multiuser detector ...

detection of multiuser signals, coupled with associated challenges in achieving this potential at affordable receiver complexity, has motivated significant amount of research to be carried out in the area of multiuser detection (MUD) in the past two decades. Much of the early research in this important area has been centered around systems employing code division multiple access (CDMA) promisin...

The link level performance and the cellular system capacity in the uplink direction of a CDMA cellular system utilising multiuser detection base station receivers is analysed by simulation. In the receiver, parallel multistage multiuser detection is employed together with two-antenna diversity reception and fast closed-loop power control. A system level simulator is built to utilise the link le...

Optimum multiuser detection for Code Division Multiple Access (CDMA) systems requires the solution of an NPhard combinatorial optimization problem. It is well known that the computational complexity of the optimum multiuser detector is exponential with the number of active users in the system. In order to reduce the complexity of the optimum multiuser detection, we propose a Reduced Complexity ...

Multiple-access interference (MAI) is a principal shortcoming of code division multiple access (CDMA) system. As the optimum multiuser detection (MUD) can’t be realized in practice, more attentions are paid to suboptimum detection scheme. We investigated the application of Hopfield neural network (HNN) to the problem of multiuser detection in Multicarrier CDMA(MC-CDMA) communica -tion systems i...

A recursive quadratic programming (RQP) approach is proposed for multiuser detection in multicarrier code-division multipleaccess (MC-CDMA) systems. In this approach, the combinatorial problem associated with the optimal maximum likelihood (ML) detection is relaxed to a quadratic programming (QP) problem first and then a recursive approach is developed to improve the detection performance. Comp...