Date Added: Mar 2012
An adaptive Turbo Trellis Coded Modulation (ATTCM) aided Cognitive Radio (CR) scheme is proposed for cooperative communication among Primary Users (PUs) and Cognitive Users (CUs). The new cooperative protocol allows a CU to serve as a Relay Node (RN) for relaying the signal of the first PU, which is a Source Node (SN) to the second PU, which is a Destination Node (DN). More specifically, an active cooperation between the PU and the CU would lead to a reduction of the transmission power and/or to an increased transmission rate for the PU. These benefits may be translated into a reduced transmission bandwidth and the freed bandwidth may be leased to a group of CUs for their secondary communications.