The Research Of Synchronization Technology In Continuous Phase Modulation System

Continuous Phase Modulation (CPM) is a bandwidth and power efficient signal processing method, with high spectral efficiency and small radiation, which is suitable for wireless and mobile communications. Meanwhile, the synchronization is a very important process in continuous phase modulation.This article analyzes the characteristics of continuous phase modulated signals, describes the working principles of CPM, and the MSK, GMSK signals are analyzed to compare the two CPM signal forms. The parameters that affect the performance of the CPM signals were analyzed.The CPM signals called OM2RC which is used in this system is discussed in detail. Meanwhile, the two channel coding:Turbo and LDPC are discussed, however, the LDPC code that used in the paper is the main issue.Therefore, the common synchronization methods are mainly based on the parameters needed to be synchronized. This paper analyzes the frequency synchronization, frame synchronization and bit synchronization method which use the pseudo-random sequence as the header to carry synchronization information while communication. So, in order to make better use of the nature of these pseudo-random sequence, the paper describes various sequences of synchronization code words which are widely used in communication systems, and for different situations, the characteristic of the pseudo-random sequence are given out in some conditions.The paper is mainly on two systems, whose synchronization algorithm are researched simulated. In the experimental stage, there are two main algorithms, one is taking advantage of the characteristics of CPM, a phase compensation algorithm is given out at the receiving end according to pseudo-random sequence carried the header synchronization information in the Gaussian channel which makes phase shift, its core idea is to through the header, to detect the received signal phase, and to compare it with the pre-given threshold to reach the effect of phase compensation, in the acceptable range of the system, also the threshold can be adjusted to meet different performance requirements. Meanwhile, for the defects of the synchronization algorithm systems with higher complexity, long delay, a CPM detection algorithm is proposed, whose main idea is to through the nature of the characteristic equation of the pseudo-random sequence while establishing the model to judge the synchronization effect of the receive signals separately. For these algorithms, the system simulation is given out in the paper for future more in-depth theoretical study and laid the foundation for hardware implementation.