DocumentCode :
2980570
Title :
Multiuser detection in large-dimension multicode MIMO-CDMA systems with higher-order modulation
Author :
Som, Pritam ; Chockalingam, A.
Author_Institution :
Dept. of ECE, Indian Inst. of Sci., Bangalore, India
fYear :
2011
fDate :
7-10 Nov. 2011
Firstpage :
364
Lastpage :
370
Abstract :
In this paper, we are interested in high spectral efficiency multicode CDMA systems with large number of users employing single/multiple transmit antennas and higher-order modulation. In particular, we consider a local neighborhood search based multiuser detection algorithm which offers very good performance and complexity, suited for systems with large number of users employing M-QAM/M-PSK. We apply the algorithm on the chip matched filter output vector. We demonstrate near-single user (SU) performance of the algorithm in CDMA systems with large number of users using 4-QAM/16-QAM/64-QAM/8-PSK on AWGN, frequency-flat, and frequency-selective fading channels. We further show that the algorithm performs very well in multicode multiple-input multiple-output (MIMO) CDMA systems as well, outperforming other linear detectors and interference cancelers reported in the literature for such systems. The per-symbol complexity of the search algorithm is O(K2n2tn2cM), K: number of users, nt: number of transmit antennas at each user, nc: number of spreading codes multiplexed on each transmit antenna, M: modulation alphabet size, making the algorithm attractive for multiuser detection in large-dimension multicode MIMO-CDMA systems with M-QAM.
Keywords :
AWGN; MIMO communication; code division multiple access; fading channels; multiuser detection; phase shift keying; quadrature amplitude modulation; transmitting antennas; AWGN; M-PSK; M-QAM; chip matched filter output vector; frequency-selective fading channels; higher-order modulation; large-dimension multicode MIMO-CDMA systems; local neighborhood search; multiuser detection; per-symbol complexity; transmit antennas; Bit error rate; Detectors; Multiaccess communication; Quadrature amplitude modulation; Receiving antennas; Vectors; DS-CDMA; Multicode MIMO; higher-order modulation; local neighborhood search; near-optimal performance;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
MILITARY COMMUNICATIONS CONFERENCE, 2011 - MILCOM 2011
Conference_Location :
Baltimore, MD
ISSN :
2155-7578
Print_ISBN :
978-1-4673-0079-7
Type :
conf
DOI :
10.1109/MILCOM.2011.6127695
Filename :
6127695
Link To Document :
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