Research On Key Technology Of Single Carrier Frequency Domain Equalization For Continuous Phase Modulation

Today, people have a ever-increasing demand in the variety of communication service and communication bit rate. They hope mobile communication can have high-quality, broadband features like the fix-line communication. However, the increase of communication bandwidth will inevitably lead to serious multi-path inter-symbol interference, making signals suffering from frequency selective fading effects. SCFDE technology is a good way of anti-fading. It provides a viable solution to multipath interference for low complexity .At the same time,the CPM signal has been a very wide range of applications because of its good characteristics of constant envelope and high spectral efficiency, power efficiency. Therefore, the combination of CPM signal and SCFDE has a very great prospect.We first analyzed the strength of the CPM signal and SCFDE,and gave an account of the CPM-SCFDE research lately. Then, we further described the principles of continuous phase modulation, including its power spectrum features and the Euclidean distance. We compared the differences between SCFDE and OFDM systems, and analyzed the principle of SCFDE in depth. Then, the wireless fading channel is modeled, using the classical discrete impulse response model. The channels used in the simulation of this system were typical urban fading channel and air-ground data link channels.Secondly, we focused on the synchronization algorithms of CPM-SCFDE receiver, including the arrival detection, timing error estimation, frequency offset estimation and initial phase estimation. Then the simulation of these algorithms in the fading channel were carried out and analyzed. We introduced the interpolation theory and implementation to compensate time error, and a loop tracking solution for parameter drift in high-speed data transmission system.Finally, we combined CPM and SCFDE technologies,and solved the difficulties of CPM signal using frequency domain equalization. We used the phase-zeroing method to ensure phase continuity of the CPM signal after adding cyclic prefix , and used discrete linear representation of CPM for frequency-domain equalization. Then begin with channel state information known at the receiving end,we simulated and analyzed MSK and TCM-4CPM signals over the air-ground data link channels and urban fading channel. Then the actual situation of the channel was taken into account, we estimated the channel information and SNR,designed of the channel estimation training word. At last, we maked the overall simulation of MSK and TCM-4CPM signals in the actual channel case. Simulation results showed that, CPM signal combining with frequency domain equalization technology can be a good way of fighting against frequency-selective fading.