Linear combination based energy detection algorithm under low SNR for cognitive radios

The LC algorithm is proposed to detect PU signal, especially under low SNR. We describe the LC algorithm, and derive the optimal decision threshold for the proposed LC algorithm. Simulation results show that the LC based spectrum sensing algorithm always outperforms the two conventional criteria. Compared with the CFAR criterion and the CDR criterion, the LC algorithm has more than 8dB gain in SNR.