Research On Sparse Channel Estimation Algorithm Based On Orthogonal Matching Pursuit In OFDM Systems

Orthogonal Frequency Division Multiplexing is a technology of multi-carrier modulation and multiplexing.It has been widely used in various high speed data transmission field.OFDM technology is widely used in field of high-speed data transmission.Channel estimation has a direct impact on the performance of OFDM system,channel estimation is the fundament of coherent demodulation and equalization.Inherent sparse makes wireless multipath channel of channel estimation based on compression perception has been widely applied.Therefore,the compression perception theory is a hotspot of current research.Firstly,the thesis introduces the radio channel transmission characteristics,focusing on the principle of multipath propagation and effect.The thesis elaborate on the principle of OFDM system,include the principle of OFDM modulation and demodulation,the effect of the guard interval and cyclic prefix.On this basis,the characteristics of sparse multipath channel were mainly studied.Secondly,the thesis analyzes the basic theory of sparse channel estimation model and compression perception,research is mainly focused on the orthogonal matching pursuit algorithm based on adaptive sparse channel estimation.On the analysis of the shortcomings and the insufficiency of the adaptive setting step,the new variable step size adaptive sparse channel estimation is proposed.Simulation results show that the proposed algorithm under the condition of large signal-to-noise ratio,and is a good way to solve the problem of iterations and the estimation error,at the same time can realize accurate approximation of sparse channel impulse response,make the bit error rate and mean square error further decrease,and improve the accuracy of channel estimation.Finally,the thesis deeply studied the sparse channel estimation based on weak choice ROMP algorithm,the study found that due to the weak choice factor value is a scope,so the choice of atomic number is not fixed,sparse degree lead to channel estimation.So this article will be limited rule of isometric characteristics(RIP)is applied to the sparse channel estimation,through RIP theorem sparse degree of adaptive estimation algorithm is proposed.Simulation experiments show that the improved algorithm is proposed in this paper can maximum limit and sparse degree of approaching channel,make the bit error rate and mean square error further decrease,and get a more accurate channel frequency response.