Title :
Antenna diversity for a narrow-band successive-cancellation multiuser detector
Author :
Janssen, Gerard J M ; Slimane, Slimane Ben
Author_Institution :
Wireless & Mobile Commun. Group, Delft Univ. of Technol., Netherlands
Abstract :
The performance of a successive-cancellation multiuser detector (SC-MUD) for narrow-band signals operating in the Rayleigh-fading channel is shown to deteriorate severely unless very large power margins at the receiver are maintained. To mitigate this deterioration, antenna diversity is applied and adapted to the SC-MUD. In each detection stage, the best signal for detection and the corresponding combining weights are determined jointly. Two criteria for selecting the best signal based on maximizing the signal-to-noise-plus-interference ratio and maximizing the minimum distance-to-noise ratio, respectively, are proposed and evaluated. For signal combining, zero forcing and minimum mean square error (mmse) combining are considered. The obtained results show that the SC-MUD with mmse combining performs close to maximum likelihood joint detection while keeping a much lower computational complexity when the number of users is less than the number of receive antennas. The effect of channel-estimation errors is investigated for orthogonal training sequences and shown to result in a minor degradation compared to perfect estimation.
Keywords :
Rayleigh channels; channel estimation; computational complexity; diversity reception; error statistics; interference suppression; least mean squares methods; maximum likelihood detection; multiuser detection; radiofrequency interference; receiving antennas; sequences; Rayleigh fading channel; antenna diversity; channel estimation errors; computational complexity; distance-to-noise ratio; error propagation; minimum mean square error combining; narrow-band successive-cancellation multiuser detector; orthogonal training sequences; receive antennas; signal combining; signal detection; signal-to-noise-plus-interference ratio; single antennas; symbol error probability; zero forcing combining; Adaptive arrays; Computational complexity; Detectors; Diversity reception; Maximum likelihood detection; Maximum likelihood estimation; Mean square error methods; Narrowband; Rayleigh channels; Signal detection; Antenna diversity; MUD; SEP; channel estimation; narrow-band multiuser detection; successive cancellation; symbol error probability;
Journal_Title :
Vehicular Technology, IEEE Transactions on
DOI :
10.1109/TVT.2004.832372