Title :
Iterative processing for joint detection in multiuser systems
Author_Institution :
Dept. of Electr. Eng., Utah Univ., Salt Lake City, UT, USA
Abstract :
Iterative (turbo) processing of multiuser detection of CDMA signals is studied. The factor graph representation of a CDMA system is used to motivate an iterative joint detection algorithm. The algorithm reduces complexity by replacing the large sums that appear at the multiple access nodes by simple averages. This system shows surprisingly good performance achieving single user performance, whenever the iterations can start successfully. It is shown how this is related almost exclusively to the behavior for the error control codes at low signal-to-noise ratio values. Simulation and analytical results on the performance of these detectors are shown to illustrate complexity/performance trade-offs
Keywords :
code division multiple access; computational complexity; error correction codes; interference suppression; iterative decoding; iterative methods; multiuser channels; noise; signal detection; turbo codes; CDMA signals; CDMA system; algorithm; complexity reduction; complexity/performance trade-offs; error control codes; factor graph representation; iterative cancellation system; iterative decoding; iterative joint detection algorithm; iterative processing; joint detection; low signal-to-noise ratio; multiple access nodes; multiuser detection; multiuser systems; simulation results; single user performance; soft-output FEC decoders; soft-output interference canceller; turbo codes; turbo processing; Analytical models; Detection algorithms; Error correction; Iterative algorithms; Multiaccess communication; Multiuser detection; Performance analysis; Signal detection; Signal processing; Signal to noise ratio;
Conference_Titel :
Spread Spectrum Techniques and Applications, 2000 IEEE Sixth International Symposium on
Conference_Location :
Parsippany, NJ
Print_ISBN :
0-7803-6560-7
DOI :
10.1109/ISSSTA.2000.876501
