Adaptive Optimization of an Iterative Multiuser Detector for Turbo-Coded CDMA
Journal article, 2008
Extrinsic information transfer (EXIT) charts are utilized to optimize the iterative multiuser detector receiver in a multiuser turbo-coded CDMA system. The (receive) power levels are optimized for the system load using a constrained nonlinear optimization approach. The optimal decoding schedule is derived dynamically using the power optimized EXIT chart and a Viterbi search algorithm. Dynamic scheduling is shown to be a more flexible approach which results in a more stable QoS for a typical system configuration than one-shot scheduling, and large complexity savings over a receiver without scheduling. We verify through simulations that complexity savings of over 50% and power savings of over 8dB can be achieved. We show that the optimized power levels combined with adaptive scheduling allows for efficient utilization of receiver resources for heavily loaded systems.
CONCATENATED CODES
transmission technology
Multiuser detection
transmission technology
CDMA
CONVERGENCE ANALYSIS
wireless access
source/channel coding
Author
David P. Shepherd
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Australian National University
Fredrik Brännström
Chalmers, Signals and Systems, Communication, Antennas and Optical Networks
Frank Schreckenbach
Technical University of Munich
Zhenning Shi
Australian National University
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Mark C. Reed
Australian National University
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
IEEE Transactions on Wireless Communications
15361276 (ISSN) 15582248 (eISSN)
Vol. 7 11 4284-4293 4684604Areas of Advance
Information and Communication Technology
Subject Categories
Telecommunications
DOI
10.1109/T-WC.2008.070557