Cooperative automatic modulation recognition in cognitive radio

In this article, a new effective method of cooperative modulation recognition (CMR) is proposed to recognize different modulation types of primary user for cognitive radio receivers. In the cognitive radio (CR) system, two CR users respectively send their feature parameters to the cooperative recognition center, which is composed of back propagation neural network (BPNN). With two users' cooperation and the application of an error back propagation learning algorithm with momentum, the center improves the performance of modulation recognition, especially when one of the CR users' signal-to-noise ratio (SNR) is low. To measure the performance of the proposed method, simulations are carried out to classify different types of modulated signals corrupted by additive white Gaussian noise (AWGN). The simulation results show that this cooperation algorithm has a better recognition performance than those without cooperation.