An energy efficiency heuristic algorithm for joint optimization in cognitive radio networks

In this paper, focusing on the all-layer involved performance analysis of cognitive radio network for overlay fashion, we propose a joint QoS-aware flow control, routing selection, channel and power allocation with an energy efficiency heuristic algorithm (EeHA). It is a NP-hard problem involving the interactions and restrictions between and across layers; therefore, we put forward a suboptimal solution which approaches the solution by a step-by-step method. First, the power and channel are pre-allocated, basing on the concept of probabilistic capability which reflects the spectrum availability and stability in dynamic spectrum environment; second, a QoS-aware routing selection algorithm is executed. Here, the routing table is set up according to available physical connection and value of probabilistic capability. Then, traffic balance is imposed to guarantee load and avoid unfair congestions on each path. At last, power is adjusted on each channel so that the system energy consumption is further reduced. Simulation results show that the proposed EeHA solved the joint optimization problem efficiently compared with traditional schemes.