Decision feedback neural network coherent receivers for continuous phase modulation based on frequency domain

This paper presents a decision feedback neural network (NN) coherent receiver scheme for continuous phase modulation based on frequency domain. Through decision feedback pre-processing, the effect of the previous transmitted symbols can be removed for the present symbol decision. By employing a Karhunen-Loeve transform (KLT) or discrete cosine transform (DCT), the input data number of neural networks can be reduced significantly. To obtain more sufficient convergence of neural networks a modified “delta-bar-delta” BP learning algorithm is proposed. Despite the low complexity in NN training and implementation, computer simulation results show that our NN receivers can achieve near optimal demodulation performance