The Modulation And Demodulation Of MSK Signal

As an important research area and development direction of modern communication technology, software radio is developing rapidly. However, the contradiction between a lot of computing demand for the software radio and the level of computing resource which the current hardware can provide becomes the bottleneck of the development of software radio. To solve this contradiction, we can make efforts in two aspects. On the one hand we can develop integrated circuits and improve the performance of the devices, on the other hand we should break through the limit of the devices’ level and make more research on theory to propose new solutions. We also should propose new signal processing algorithms, especially the modulation and demodulation algorithms which demands less computing amount, because the modulation and demodulation algorithms take an extremely important position. Moreover, the complexity of demodulation algorithm has become a standard to determine the performance of the system.In this article the MSK, an important branch of constant envelope continuous phase modulation technique is studied. MSK has a lot of advantages, such as constant envelope, continuous phase, concentrated power spectral density and high bandwidth efficiency, which make MSK of great significance in the research and applications of signal theory. The subject of the research on the development of software radio technology has certain reference value.In the first part of this article, the research background is introduced. Then the basic theory of software radio, including the sampling theorem and equiripple digital filter designing is discussed. And a brief presentation on the simulation environment is given in the same chapter, too. They are the foundation of the entire experiment system structure. In the third chapter, the detailed basic principles of minimum shift keying modulation is introduced, and the MSK signal generation method and simulation results are given in the fourth chapter. Chapter5focuses on the existing demodulation algorithm of the MSK signal, and some of these algorithms are given simulation test and analysis. In Chapter6the principle on the steepest descent method which is used in simulation experiment channel estimation is described. The seventh chapter is a summary of the entire article and prospects.