The Research And FPGA Implementation Of Chirp Signal Detection

In recent years,the State Grid has proposed Broadband Micro-power wireless meter reading technology with strong anti-interference ability and low power consumption to replace Narrowband Micro-power meter reading technology.The Chirp signal is selected as the transmission signal of the Broadband Micro-power wireless communication system has its unique advantages.,because its spectrum modulation technology is in line with the requirements of broadband micro-power wireless meter reading technology.It is necessary to detect the signals for monitor the channel of broadband micro-power wireless communication system and identify useful signals.Therefore,the research on Chirp signal detection has important significance.Firstly,this thesis analyzes the characteristics of Chirp signal,researches some typical Chirp signal detection methods,and proposes a Chirp signal detection method based on phase difference method and fractional Fourier transform.Estimates the frequency modulation slope of the Chirp signal using phase difference method,calculates the transform order of fractional Fourier transform from the FM slope estimation value.Then search the peak value of the signal in the fractional Fourier transform domain at this order,calculates the center frequency and FM slope of the Chirp signal from the peak value above.The simulation results show that the method of detecting Chirp signals by using phase difference method and fractional Fourier transform has higher detection accuracy in a low SNR environment.At the same time,the detection method proposed in this thesis needs to perform the fractional Fourier transform only once to detect the signal parameters,which greatly reduces calculations compared with the traditional Fractional Fourier Transform method that requires exhaustive detection.The Chirp signal detection method based on phase difference method and fractional Fourier transform accords with the performance requirements of a broadband micropower wireless communication system.Via using the Verilog HDL language,the FPGA implementation scheme of the Chirp signal detection applied to the broadband micropower wireless communication system is designed.The circuit synthesis results show that the resource consumption of hardware implementation scheme is less.Finally,the FPGA implementation is tested and verified via the hardware test platform.The tested results show that the function of the designed scheme is correct.The desired effect is achieved.The Chirp signal detection and FPGA implementation scheme designed in this thesis provides a reference for the design of a new generation of broadband micro-power wireless communication system,which has certain practical value.