Non Iterative Algorithm for Multi-user Detection in DS-CDMA System: An Enhanced Harmony Search Algorithm (original) (raw)
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Iterative Multiuser Detection and Channel Decoding for DS-CDMA Using Harmony Search
IEEE Signal Processing Letters, 2000
A novel random-guided optimization method is proposed for multiuser detection (MUD) in DS-CDMA systems employing the so-called Harmony Search (HS) algorithm. We specifically design the HS-aided MUD for the communications problem considered and apply it in an iterative joint MUD and channel decoding framework. Our simulation results demonstrate that a near-single-user performance can be achieved without the employment of the full-search-based optimum MUD even in extremely highly loaded DS-CDMA systems.
2010 IEEE 72nd Vehicular Technology Conference - Fall, 2010
A novel Multiuser Detection (MUD) scheme is proposed for DS-CDMA systems employing the so-called Harmony Search (HS) algorithm, which is a novel meta-heuristic optimisation method. We specifically design the HS aided MUD for the communications problem considered and apply it in an iterative joint Channel Estimation (CE), MUD and channel decoding framework. The simulation results demonstrate that a near-single-user performance can be achieved by the proposed algorithm while avoiding the excessive-complexity full-searchbased optimum detection even in overloaded DS-CDMA systems. Moreover, the HS algorithm can be efficiently applied in the Expectation Maximisation (EM) based CE framework.
Harmony Search Heuristics for Quasi-asynchronous CDMA Detection with M-PAM Signalling
2012
Focusing on CDMA (Code Division Multiple Access) uplink communications, this paper addresses the application of heuristic techniques to the multiple user detection problem when dealing with asynchrony between transmitters and bandwidth-limited PAM (Pulse Amplitude Modulation) signals. In such systems it is known that, even for the simplest case of binary modulated signals with perfectly synchronous transmitters, simple Single-User Detection (SUD) techniques (e.g. Rake receiver) are outperformed by Multiple-User Detection (MUD) schemes (based on the Maximum-Likelihood-ML-criteria), at a computational cost exponentially increasing with the number of users. Consequently, Genetic Algorithms (GA) have been extensively studied during the last decade as a means to alleviate the computational complexity of CDMA MUD detectors while incurring, at the same time, in a negligible error rate penalty. In this manuscript, a novel heuristic approach inspired in the recent Harmony Search algorithm will be shown to provide a faster convergence and a better error rate performance than conventional GA's in presence of inter-user asynchrony in bandwidth-limited CDMA communications, specially when the complexity of the scenario increases.
A new hybrid heuristic multiuser detector for DS-CDMA communication systems
Wireless Communications and Mobile Computing, 2009
In this work, we present a new multiuser detection (MUD) structure which results from incorporating the tabu search (TS) heuristic algorithm with the local search (LS) heuristic algorithm. The new proposed structure brings much improvement when compared to both the conventional (matched filter) detector and the decorrelating detector. Moreover, the new TS-LS-detector proposed here approximates well the performance of the optimal MUD detector but with a very low computational complexity. Copyright © 2008 John Wiley & Sons, Ltd.
Multi-User Detection In DS-CDMA System Using Biogeography Based Optimization
To attain large information rates, code division multiple access (CDMA) is a well-built aspirant for the downlink of cell phone communications. However, while transmitting any signal over fading channel, the performance of CDMA system is highly affected. For that reason, Multiuser detection (MUD) and channel estimation play a significant function for overcoming the interference and characterizing the channel. In this paper, biogeography base optimization (BBO) algorithm introduced for multiuser detection CDMA system. The objective of BBO algorithm is used to minimize the error rate of the user transmitting signal. According to immigration rate and emigration rate, the optimal solution of the detection problem is decided. Therefore, the user detection complexity and the interference of user transmitting signal are resolved. Proposed multiuser detection algorithm is appropriate for run time user identification process; since the detection complication and the required time are concentrated. The proposed approach is implemented in MATLAB working platform and the performance measures are examined. The error rate of proposed algorithm is compared with harmony search algorithm, enhanced harmony search algorithm, and without multiuser detection procedure.