作者机构:[1]Department of Communication Engineering, Yunnan University, Kunming 650091, China, [2]Information Center of Educational and Scientific Institute, Educational Department of Yunnan Province, Kunming 650223, China
相关基金:Supported by the National Natural Science Foundation of China (No. 60362001 )
The authors thank the Department of Communication Engineering, Yunnan University, Kunming, China for their supporting of the research work. ]'he suggestions and comments made by our colleagues to improve the paper are also gratefully acknowl- edged.