New Estimators for Primary Channel Gain in Cognitive Radio Networks

The channel gain from the primary transmitter to the primary receiver is an important system parameter that is required for the efficient operation of cognitive radio networks. In this letter, two new estimators for the primary channel gain are derived by using the received signals directly based on the method of moments. The estimation is performed at the cognitive radio independently without any cooperation from the primary user. Both Rayleigh and Nakagami-m fading channels are considered. The proposed estimators are much simpler and less restrictive than the existing estimators. Numerical results also show that they can outperform the existing estimators in many cases.