Title :
A family of likelihood ascent search multiuser detectors: approaching optimum performance via random multicodes with linear complexity
Author_Institution :
City Coll., Dept. of Electr. Eng., City Univ. of New York, New York, NY, USA
Abstract :
Tse and Verdu proved that the global maximum likelihood (GML) detector achieves unit asymptotic multiuser efficiency (AME) in the limit of large random spreading CDMA. In this paper, we show that the wide-sense sequential likelihood ascent search (WSLAS) detectors achieve unit AME with channel load < 1/2 - 1/(4 ln 2) bits/s/Hz. In simulations for random multicode equal-power systems, the WSLAS with a linear per-bit complexity approaches the GML BER in all SNR with channel load as high as 1.05 bits/s/Hz.
Keywords :
code division multiple access; computational complexity; error statistics; maximum likelihood detection; multiuser detection; BER; CDMA; asymptotic multiuser efficiency; bit error rates; code division multiple access; global maximum likelihood detector; likelihood ascent search multiuser detectors; linear complexity; random multicode equal-power systems; random multicodes; Belief propagation; Bit error rate; Detectors; Gaussian approximation; H infinity control; Maximum likelihood detection; Multiaccess communication; Object detection; Sun; Time division multiple access; Multiaccess communication, nonlinear detection, maximum likelihood detection;
Journal_Title :
Communications, IEEE Transactions on
DOI :
10.1109/TCOMM.2009.08.070153
