Optimal Cooperative Spectrum Sensing in Cognitive Radio with Taguchi Method

Spectrum sensing is an essential topic in cognitive radio networks to detect primary users. Cooperative spectrum sensing with linear fusion scheme is studied in multiband channel systems. The problem turns out to be a nonconvex optimization problem in general with thresholds of the energy detectors and the weights of linear fusion scheme as parameters. In this paper, we use the Taguchi method to estimate the gradient of the aggregate throughput function, determine thresholds of the energy detector and linear combination weights of the linear fusion rule. One of the advantages of our approach is to optimize the thresholds and the linear weights simultaneously. In addition, we modify the input parameters of experiments to satisfy the constraints before we calculate the cost and analyze the trends, and it improves the computation and search efficiency. Simulation results show that the proposed method can be used in all classes of CR. Our approach has a very good performance with short computational time and it is also insensitive to initial values of parameters and gives a relatively stable result.