Research On Key Technologies Of Mono-bit Digital Receiver

With the development of modern science and technology,the traditional instantaneous frequency measurement receiver can not meet the requirements of miniaturization and low power consumption of electronic warfare.Therefore,some scholars propose to use a low precision ADC instead of a high precision ADC for the single bit receiver.Compared with the traditional instantaneous frequency measurement receiver,the single bit receiver is easier to achieve high-speed sampling,and has the advantages of small volume,low power consumption,and can integrate the whole receiver It has the advantages of single chip and multi signal resolution,but its dual tone dynamic range is small.In order to improve this problem,this paper studies the frequency measurement performance of single bit receiver,and proposes the frequency measurement method of segmented filtering with high detection rate and error detection result correction method.(1)This paper introduces the research background and significance of single bit receiver and the research status of digital receiver at home and abroad,analyzes the principle of sampling module and FFT module of single bit receiver,deduces the mathematical expressions of low bit ADC and rotation factor quantization,compares the spectrum of 1 ? 4 bit ADC sampling quantization after 4-point rotation factor quantization and 8-point rotation factor quantization FFT,and selects the best one Low bit ADC and rotation factor quantization are combined to simulate the frequency measurement accuracy,dual tone dynamic range and single signal dynamic range of these combinations.It is found that the single signal dynamic range is almost the same,and the dual tone dynamic range increases with the increase of sampling bits.(2)Since the traditional threshold frequency selection method has weak detection ability for the signal with large normalized amplitude difference of input signal,this paper proposes a segmented filtering high detection rate frequency measurement method.The principle is that the signal is divided into multiple channels by using filter banks,and each channel samples and measures the frequency independently.The purpose of improving the detection rate is achieved by reducing the influence of harmonic caused by nonlinear changes.The measurement results are given The results show that the detection rate is improved by 14% when the normalized amplitude difference is 3 d B and 40% when the normalized amplitude difference is 6 d B.(3)Based on the statistics and analysis of the false detection data after frequency measurement,this paper proposes a method to correct the false detection results.The correction matrix is set according to the repeated false detection results.When the system measures double signals,the correction matrix is looked up to correct the false detection results.The selection method of the correction matrix is given,and the effectiveness of the correction method is verified by simulation True results under the condition of dual channel frequency measurement,the detection rate increases by 5% when the normalized amplitude difference is 4d B,and 22% when the normalized amplitude difference is 6d B.(4)Matlab is used to simulate the system,and the overall framework of the system is built in the Simulink environment.The segmented filter high detection rate frequency measurement method mentioned in this paper is simulated by several filter banks.The simulation results show that 2-3 filters are the best,and the application scope of the error detection correction method is simulated.The results show that the ADC acquisition quantization is the best when it is less than 4 bits.