DocumentCode :
2460824
Title :
Distributed Space-Time Code Using Precoding for Cellular Systems
Author :
Teodoro, Sara ; Silva, Adão ; Gil, João M. ; Gameiro, Atílio
Author_Institution :
Inst. de Telecomun., Univ. of Aveiro, Aveiro, Portugal
fYear :
2010
fDate :
6-9 Sept. 2010
Firstpage :
1
Lastpage :
5
Abstract :
We propose a data precoded relay-assisted scheme, for a system cooperating with 2 relays. We assume that all the terminals are equipped with a single antenna. The use of relays is of significant interest to allow radio access in situations where a direct path is not available. However because of the half duplex constraint at the relays, transmission of a data rate equivalent to that of a modulation technique with m bits per symbol in the case a continuous link would be available from the BS to the UT requires the use of a constellation with 2m bits per symbol. This implies a penalty in power efficiency. The proposed simple precoding scheme exploits the relation between QPSK and 16-QAM, by alternately transmitting through the 2 relays, keeping the diversity of order 2. Numerical results show significant performance improvements relatively to the case of a relay-based distributed Alamouti employing 16-QAM, and a performance very close to the non-cooperative system employing 2x1 QPSK Alamouti coding with a continuous link available, when all the links have the same SNR.
Keywords :
cellular radio; diversity reception; modulation coding; precoding; quadrature amplitude modulation; quadrature phase shift keying; space-time codes; 16-QAM; Alamouti coding; QPSK; cellular systems; cooperative diversity; data precoded relay-assisted scheme; distributed space-time code; power efficiency; quadrature amplitude modulation; quadrature phase shift keying; Antenna arrays; Decoding; Encoding; Gain; Phase shift keying; Relays; Viterbi algorithm;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Vehicular Technology Conference Fall (VTC 2010-Fall), 2010 IEEE 72nd
Conference_Location :
Ottawa, ON
ISSN :
1090-3038
Print_ISBN :
978-1-4244-3573-9
Electronic_ISBN :
1090-3038
Type :
conf
DOI :
10.1109/VETECF.2010.5594294
Filename :
5594294
Link To Document :
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