The Design And Implement Of CPM Receiver In Digital Microwave System

With the increasing requirement of voice and video transmission capability in wireless channel, more and more wireless communication systems are created, and many of them are using microwave. In the communication system, the modulation is the key technique, affecting the performance of the communication system. The Continuous Phase Modulation (CPM) is suitable in digital microwave communication with the high spectral efficiency. But the CPM receiver in digital microwave system is quite complex and hard or expensive to implement. The content of this paper is to research a reduced-complexity receiver which is suitable in digital microwave.This paper first introduces the model of CPM signal, and the modulation and demodulation of CPM. After the analysis of the complexity of the receiver, the paper then introduces some previous work on reduced-complexity receivers for CPM.Although CPM is suitable for digital microwave communication, the CPM receiver is more complex than the traditional receiver, because of the use of Non-coherent differential detection. So the 4^th chapter introduces a new reduced-complexity receiver combining the differential detection and soft- decision phase detection. With the simulation of this receiver, the result shows that the receiver can reduce the complexity of the receiver with some performance decline.At the end of this paper, the receiver is implemented with FPGA. With the design of modules and connection, the receiver is built. The function simulation result and the analysis of the data indicate that the implement of the receiver is correct.