Research And Implementation Of The Key Technology Of Multiple Diversity Reception For HF Communication

HF communication has become a very important communication mode in modernmilitary, due to its advantages of high flexibility and strong anti-destructive. However,the performance of HF communication is bad because of the multipath effect andDoppler effect in HF channels. In this thesis, technologies of data detection anddiversity receiving are presented and analyzed as new options to improve theperformance of HF communication.In part one, the equivalent baseband model of HF channels is provided based onthe characteristics of HF channels. Then according to the analysis of performance ofRLS and LMS algorithms and the fading characteristics of the HF channels, a modifiedRLS algorithm with variable forgetting factor is introduced. Finally, to eliminate theinfluence of the ISI, a fast algorithm of nonlinear data directed estimation is providedafter analyzing the performance of original data directed estimation and nonlinear datadirected estimation algorithm. In part two, based on analysis of diversity receptiontechniques in the HF communication, two kinds of maximal ratio combining techniquesand their performance simulation are provided.In last part of the thesis, the practical problems in the implementation based onDSP TMS320C6713hardware platform are discussed and the solutions to them are alsogiven.