Efficient energy detector for spectrum sensing in complex Gaussian noise

The energy detector is a very useful detector for spectrum sensing in cognitive radio systems and has been widely employed for sensing optimization. However, there is certain mismatch between the theoretical and actual detection performance of the conventional energy detector in complex Gaussian noise, which will undermine the optimization accuracy. To solve this problem, an efficient energy detector in complex Gaussian noise is proposed and its theoretical detection performance expressions are derived based on the approximated distributions of its test statistic under different hypothesis. Numerical results show that compared with the conventional energy detector the new energy detector offers superior detection performance and its theoretical detection performance is almost as same as the actual one, which confirms the new energy detector's efficiency and is of great importance for the design of optimal spectrum sensing in cognitive radio systems.