A Spectrum Leasing Cooperative Medium Access Protocol and its Stability Analysis

We analyze the stability of a cooperative spectrum leasing system that exploits our “win-win” (WW) cooperative medium access control (MAC), where the relay node (RN) forms a coalition with the source node (SN) to exploit the benefits of spectrum leasing. In this coalition, the licensed SN may achieve its target rate at a reduced energy consumption by leasing part of its spectral resources. As an incentive, the unlicensed RN earns a transmission opportunity for conveying its traffic by jointly encoding both the source´s and its own data with the aid of superposition coding. The destination employs successive interference cancelation for decoding the superimposed source-relay data received from the relay and retrieves the source data by appropriately combining the direct and relayed components. Based on our WW cooperative MAC protocol, we analyze the queueing stability and quantify the achievable steady-state throughput of both SN and RN.