DocumentCode :
1008277
Title :
Blind Schemes for Asynchronous CDMA Systems on Dispersive MIMO Channels
Author :
Grossi, Emanuele ; Lops, Marco ; Venturino, Luca
Author_Institution :
Univ. degli Studi di Cassino, Cassino
Volume :
6
Issue :
6
fYear :
2007
fDate :
6/1/2007 12:00:00 AM
Firstpage :
2066
Lastpage :
2075
Abstract :
The problem of blind detection in a dispersive multiple-input multiple-output (MIMO) code division multiple access (CDMA) channel is considered in this paper. Unlike previous studies, each user is assigned one spreading code to be employed on all of the transmit antennas, which poses a problem of data re-association at the receiver-end in the absence of prior information as to the channel state. Focusing on the differential Alamouti scheme, we propose a two-stage receive structure. The first stage performs a linear interference-blocking transformation, which allows user separation and inter-symbol interference (ISI) suppression. The second stage is, instead, a novel differential space-time block (STB) decoder suitable for frequency-selective channels. Interestingly, the proposed detector allows decoupling of the decisions on the transmitted symbols, while its blind implementation only requires a cubic (in the processing gain) complexity. A thorough performance assessment is undertaken to investigate, on one hand, the capability of acquiring the missing information, such as the system and the encoder timings, on the other hand, the interplay between the diversity gain provided by the MIMO structure of the communication system, and the additional co-channel interference that multiple transmit antennas produce in multi-path, multiple-access channels.
Keywords :
MIMO communication; code division multiple access; fading channels; interference suppression; multipath channels; Alamouti scheme; asynchronous CDMA systems; blind detection; co-channel interference; code division multiple access channel; communication system; dispersive MIMO channels; frequency-selective channels; inter-symbol interference suppression; linear interference-blocking transformation; multipath channels; multiple transmit antennas; multiple-access channels; multiple-input multiple-output; space-time block decoder; two-stage receive structure; Decoding; Dispersion; Frequency; Interference suppression; Intersymbol interference; MIMO; Multiaccess communication; Receiving antennas; Transmitting antennas; US Department of Transportation;
fLanguage :
English
Journal_Title :
Wireless Communications, IEEE Transactions on
Publisher :
ieee
ISSN :
1536-1276
Type :
jour
DOI :
10.1109/TWC.2007.05502
Filename :
4251150
Link To Document :
بازگشت