Submitted on: 30 May 2007.
Revised on: 19 June 2007.
Accepted on: 01 July 2007.
___________________IEEE Wireless Communications Letters
Submitted on: 16 September 2013.
Revised on: 16 October 2013.
Accepted on: 03 November 2013.
___________________IEEE Wireless Communications Letters
http://reply.papertrans.cn/2/122/12115/12115-33.png
Submitted on: 22 May 2010.
Revised on: 13 August 2010.
Accepted on: 28 August 2010.
___________________IEEE Wireless Communications Letters
Submitted on: 09 November 2011.
Revised on: 19 December 2011.
Accepted on: 05 January 2012.
___________________IEEE Wireless Communications Letters
http://reply.papertrans.cn/2/122/12115/12115-36.png