Technical Research On Parameter Estimation Of Split Spectrum Signal Under Non-cooperative Conditions

The BOC modulated signal is a split spectrum signal.Its autocorrelation function has multi-peak characteristics.It has stronger anti-interference ability.Compared with the DSSS signals,the BOC modulated signal has unique characteristics.Thus a higher challenge is posed to carry out the parameter estimation.The BOC modulated signal has stronger anti-interference ability,so it will be widely used in the field of secure communication.In order to meet the needs of communications reconnaissance,technical research on parameter estimation of split spectrum signals under non-cooperative conditions has been carried out.This study has strong practical value.In this thesis,the direct-spread communication technology is studied in depth.The commonly used methods for estimating the parameters of DSSS signals are summarized and analyzed.Then,the generation mechanism of the BOC modulated signal is studied.At the same time,the multi-peak and splitting spectral characteristics of the autocorrelation function of BOC modulated signal are analyzed.By existing methods for estimating carrier frequency parameters of BOC modulated signals are analyzed in depth,the analysis shows that the existing methods have limitations.By combining set averaging techniques,the square-based multiplication of carrier frequency parameter estimation method has been improved.Through software simulation,the improved set-mean-square-frequency carrier frequency estimation method is verified.In addition,the BOC modulation sequence has the multi-peak characteristic of autocorrelation function.By combining the multi-peak characteristics of autocorrelation function,the correlation features between multiple peaks of autocorrelation are deeply tapped.By the distance between the peaks,the square-wave sub-carrier rate is estimated.Then using the difference for autocorrelation peak height,the parameter estimation of the pseudo-random sequence rate is realized.Through software simulation,the first derivative of correlation peak search algorithm is verified.Autocorrelation peak height difference search algorithm is also verified.The two algorithms are correct and effective,meanwhile,the performance of the algorithm is analyzed in detail.