Optimal sensing time of soft decision cooperative spectrum sensing in cognitive radio networks

Spectrum sensing is a key feasible technology for cognitive radio (CR). Sensing time is an important sensing parameter which brings about a sensing-throughput tradeoff. In this paper, based on soft decision schemes, we investigate the sensing-throughput tradeoff problem and analyze the impact of different system parameters on the optimal sensing time for cooperative spectrum sensing. Simulation results show that maximal ratio combination g (MRC) and modified deflection coefficient (MDC) schemes have almost the same performance which outperform equal gain combination (EGC) scheme. Further, optimal sensing time decreases with the increase of number of CR users and increases when average signal-noise-ratio (SNR) decreases.