DocumentCode :
1454970
Title :
Max-matching diversity in OFDMA systems
Author :
Bai, Bo ; Chen, Wei ; Cao, Zhigang ; Ben Letaief, Khaled
Author_Institution :
Dept. of Electron. Eng., Tsinghua Univ., Beijing, China
Volume :
58
Issue :
4
fYear :
2010
fDate :
4/1/2010 12:00:00 AM
Firstpage :
1161
Lastpage :
1171
Abstract :
This paper considers the problem of optimal subcarrier allocation in OFDMA systems to achieve the minimum outage probability while guaranteeing fairness. The optimal subcarrier allocation algorithm and the maximum frequency diversity gain are both analyzed through the maximum matching method based on the random bipartite graph theory. Accordingly, a surprising result is found, which shows that the maximum frequency diversity gain in subcarrier-sharing OFDMA systems is the same as that in point-to-point OFDM systems that serve only one user by using N subcarriers. It is then demonstrated that this maximum frequency diversity gain can be achieved by a proposed Random Vertex Rotation based Hopcroft-Karp (RVRHK) algorithm with the time complexity of O(N2.5), where N is the number of subcarriers. Because the theoretical analysis and the RVRHK algorithm are both based on the maximum matching method, the maximum frequency diversity in OFDMA systems is referred to as the max-matching diversity in this paper.
Keywords :
OFDM modulation; computational complexity; diversity reception; frequency division multiple access; graph theory; subcarrier multiplexing; Hopcroft-Karp algorithm; OFDMA systems; RVRHK algorithm; Random Vertex Rotation; max-matching diversity; maximum frequency diversity gain; maximum matching method; minimum outage probability; optimal subcarrier allocation algorithm; random bipartite graph theory; time complexity; Algorithm design and analysis; Bipartite graph; Downlink; Frequency diversity; Laboratories; OFDM; Quality of service; Resource management; Transceivers; Wireless communication; OFDMA; frequency diversity; maximum matching; outage; random bipartite graph;
fLanguage :
English
Journal_Title :
Communications, IEEE Transactions on
Publisher :
ieee
ISSN :
0090-6778
Type :
jour
DOI :
10.1109/TCOMM.2010.04.080478
Filename :
5439319
Link To Document :
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