The Research And Realization Of SNR Estimation Algorithm In Wireless Communication

The signal-to-noise ratio(SNR)is an effective indicator of signal quality in wireless communication.In Code Division Multiple Access(CDMA),Long Term Evolution(LTE)and LTE-Advanced(LTE-A)systems,SNR and noise variance are estimated for transmitter's adaptive coding modulation and interference suppression receiver.CDMA system also need SNR estimation for power control and handover.So this paper is engaged in the research of SNR estimation on the following three aspects.Firstly wireless channel characteristic and the LTE physical layer are analyzed,then the six classics SNR estimation algorithms are researched,including the M2M4,Boumard's method,LS,ML and SNV,MMSE and DFT method based on LS channel estimation.After comparison of all algorithms of performance and scenario analysis in LTE system,the paper conducts the SNR estimation simulation to compare M2M4 blind estimation and DFT estimation based on LS.Then the process of China's first generation of satellite mobile communication system based on CDMA in forward link is studied.Using the pilot through descrambling and despreading spectrum to estimate SNR is derived in detail with the corresponding simulation in CDMA.Finally,FPGA implements the forward link receiver of CDMA satellite mobile communication system.The paper analyzes hardware resource consumption and the estimation performance of bit synchronization validation module that realizes the SNR estimation.