Manuscript received January 21, 2012; revised July 21, 2012; accepted July 23, 2012. Date of publication August 31, 2012; date of current version November 29, 2012. This work is supported in part by the National Natural Science Foundation of China under Grant No. 61232001, No. 61173051 and No. 61073036, the Talent Foundation of Hunan Agricultural University No. 06YJ10, the Freedom Explore Program of Central South University No. 201012200124, and the Natural Sciences and Engineering Research council of Canada (NSERC). Asterisk indicates corresponding author. *J. Wang is with School of Information Science and Engineering, Central South University, Changsha, 410083, China (e-mail: jxwang@mail.csu.edu.cn).