Stanag 4285 Communication Standard Of Low Complexity Iterative Receiver Design

The communication system based on STANG4285standard works in short-waveband. The various forms of HF(High Frequency) propagation and propagation mediumdetermine the short-wave channel is a kind of multipath, time-varying, noisy,complicated channel, so that the received signals are usually with serious inter-symbolinterference. It brings more stringent requirements for the receiver to restore sendsignals. The aim of this paper is to design the low complexity iterative receiver in theorythat the actual system can satisfy the performance requirements, and bear the calculationamount in hardware realization.Firstly this paper gives a brief introduction to the impact of the propagationcharacteristics and transmission medium to the shortwave communication. Then bringsthe classical HF channel model of Watterson channel model and gives the simulationresult in MATLAB. Secondly elaborates the main functional modules in the STANAG4285physical layer standard in detail, and implements the transmit link with Mlanguage. According to the characteristics of the fast time-varying shortwave channel,this paper studies LMS adaptive channel estimation algorithm, and gives estimateresults to the iteration equalization algorithms for use. And then based on severalconventional low complexity Turbo equalization algorithms in the receiver, such asMMSE, MMSE-DFE, SFIC, this paper gives a detailed explanation of these iterativeequalization algorithms principle. Through the analysis of the strengths and weaknessesof these algorithms, the hybrid iterative equalization was given based on the optimizedcombination of the performance and complexity.Finally, in order to select the most suitable receiver model, not only the complexity,the iterative convergence speed and error performance of the equalization algorithmitself have to be considered, but also the impact to the complexity of SISO decodercaused by the number of iterations. This study showed that the iterative receiver with8PSK modulation of the STANAG4285shortwave communication standard, based onSFIC equalization algorithm has the best BER performance and lower complexity.