Research On Channel Estimation And Receive Algorithm In Time-frequency Double Selective Fading Channels

Along with the rapid development of science and technology innovation, people have higherrequirements for the quality of life of its own, and communication is the priority among prioritiescan not be ignored. In fact, in today’s younger generation, call service is no longer the main part ofcommunication, more and more mobile phones increase more Internet data services. In the past fewyears, wireless communication technology has played a more and more important role. In recentyears, as the core of the OFDM technology in the fourth generation wireless mobile communicationhas been widely recognized and greatly grown, people have begun to focus on the research for theexistence of the shortcomings of OFDM technology and how to minimize the sensitivity of OFDMsystem for phase noise and frequency offset, and improve the performance of transceiver algorithmin the OFDM system.The main research object of this paper is the high-speed mobile environment time-frequencywireless channel and channel fading effects on wireless communication receiving system. As theearly introduction of preparatory work, the paper introduces in detail the causes of wireless channelfading, and points out that the small scale fading effect is the main fading to the wirelesscommunication system. After that, the paper compares the slow decay channel characteristics withthe high-speed channel characteristics, and introduces the principle of algorithm for each channelestimation. The paper focuses on the basis expansion model(BEM). After that, the paper introducedtwo kinds of transceiver algorithm for the single-path system and the multi-path system.In this paper, the main contents are as follows:Firstly, the paper introduces three classic types of BEM and discusses the important parametersfor the algorithm by the simulation. On the basis, the paper analyses each performance of thealgorithm with known pilot channel frequency response and the one without the pilot informationby using the BEM. The paper points out that the algorithm may be broken in the high-speedenvironment.As the performance of transceiver system in the single path high-speed mobile environmenthas been destroyed, a algorithm using DQPSK in the spread spectrum system is proposed. Unlikethe traditional system, the proposed algorithm is firstly demodulated at the receiving end. Thesimulation results compare the performance between the proposed algorithm and the traditionalalgorithm.Finally, the paper discusses the multi-path system in the high-speed mobile environment. Asthe orthogonality between different subcarriers in OFDM system is broken in the high-speed mobile environment, the performance of OFDM system becomes worse. A novel multiple antennas angleresolution based transceiver algorithm is proposed in this paper. Compared with the traditionalalgorithm, the simulation results verify the effectiveness of the proposed algorithm.