A Peds System Research And Simulation Of Diversity Reception Method

In recent years, with China’s independent intellectual property rights of China’s Police Digital cluster(Police Digital Trunking) standards of research and development work has been successfully concluded.PDT police digital trunking standard, it is in our country, the public security authorities, led by the Chinese domestic communication system suppliers to formulate standard of digital professional wireless communication technology, it give full consideration to the public security organs in our country scheduling command communication needs, but also absorbed the relatively mature in the international standard protocol strengths, so will be in the field of public security and communications in our country the development direction of digital trunking communication system standards.However, because of PDT USES is narrowband communication technology, in addition to voice communications, unable to realize high speed Data transmission, including images, therefore the domestic current research of PEDS(Police Enhanced Data services) system is used to from narrowband cluster system to the evolution of broadband cluster system.This topic research is a method of PEDS system diversity reception of diversity reception algorithm and simulation test and field engineering.This paper on the PDT system has carried on the brief analysis is introduced, through comparison with the existing several digital clustering technology, analyzes the advantages and disadvantages of PDT system, demonstrates the PEDS research the necessity of the system.Followed by further study of the characteristics of wireless channel and the basic principle of diversity merging technology, and according to the actual requirements of PEDS, through comparing traditional diversity combining method, choose the method of spatial diversity and maximum ratio combining technology as diversity of PEDS merger.Focus on diversity reception method, after the PEDS system modeling and simulation, and the multiple diversity combination methods, a variety of environmental conditions, a variety of signal types compares the simulation results, the best diversity merger receiving scheme is determined.Then according to the actual requirements, system for synchronous way, and put forward the concrete solution, and optimize the performance of the matched filtering synchronization.Finally, according to merge when receiving phase adjustment problem, according to the principle of phase-locked loop, puts forward an optimization scheme, make the merger of the multipath signal were improved.According to the front of diversity reception algorithm and performance optimization, the diversity reception process of PEDS system has carried on the field test, at the same time, the algorithm and optimization scheme for the engineering practice, and found the problem from practice, to solve the problem.And according to the theory of performance and the analysis of the measured results, can determine the deficiency in the process of algorithm implementation, and finally has carried on the optimized processing, meet the requirements of the application of the project.