DocumentCode :
960210
Title :
Using Orthogonal and Quasi-Orthogonal Designs in Wireless Relay Networks
Author :
Jing, Yindi ; Jafarkhani, Hamid
Author_Institution :
Univ. of California, Irvine
Volume :
53
Issue :
11
fYear :
2007
Firstpage :
4106
Lastpage :
4118
Abstract :
Distributed space-time coding was proposed to achieve cooperative diversity in wireless relay networks without channel information at the relays. Using this scheme, antennas of the distributive relays work as transmit antennas of the sender and generate a space-time code at the receiver. It achieves the maximal diversity when the transmit power is infinitely large. This paper is on the design of practical distributed space-time codes (DSTCs). We use orthogonal and quasi-orthogonal designs which are originally used in the design of space-time codes for multiple-antenna systems. It is well known that orthogonal space-time codes have full diversity and linear decoding complexity. They are particularly suitable for transmissions in the network setting using distributed space-time coding since their ldquoscale-freerdquo property leads to good performance. Our simulations show that they achieve lower error rates than the random code. We also compare distributed space-time coding to selection decode-and-forward using the same orthogonal designs. Simulations show that distributed space-time coding achieves higher diversity than selection decode-and-forward (DF) when there is more than one relay. We also generalize the distributed space-time coding scheme to wireless relay networks with channel information at the relays. Although our analysis and simulations show that there is no improvement in the diversity, in some networks, having channel information at the relays saves both the transmission power and the transmission time.
Keywords :
antenna arrays; channel coding; decoding; diversity reception; linear codes; orthogonal codes; radio networks; space-time codes; channel information; cooperative diversity; distributed space-time codes; error rates; linear decoding complexity; multiple-antenna systems; orthogonal design; orthogonal space-time codes; quasiorthogonal design; transmitting antennas; wireless relay network; Analytical models; Decoding; Error analysis; Information analysis; Pairwise error probability; Receiving antennas; Relays; Transmitters; Transmitting antennas; Wireless networks; Relay network; coding gain; distributed space–time coding; diversity; orthogonal and quasi-orthogonal designs; pairwise error probability (PEP);
fLanguage :
English
Journal_Title :
Information Theory, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9448
Type :
jour
DOI :
10.1109/TIT.2007.907516
Filename :
4373409
Link To Document :
بازگشت