Instantaneous frequency measurement method based on FPGA and digital receiver thereof

Abstract

The invention discloses an instantaneous frequency measurement method based on an FPGA and a digital receiver thereof. The method comprises the following steps of: delaying the original data stream byb clock cycles, forming two real sequences with the current data stream, wherein the two real sequences are respectively used as a real part and an imaginary part to obtain complex original data stream signals; inputting the plurality of original data stream signals into an FFT (Fast Fourier Transform) operation module according to the bit width, performing butterfly operation for the output of the FFT module operation module, and inputting the output into a decomposition circuit to obtain frequency spectrums corresponding to two real sequences respectively; calculating a noise threshold according to the two complex frequency spectrums; according to the noise threshold and a set signal-to-noise ratio margin, performing searching by adopting an extreme value to obtain a coarse frequency measurement signal; demodulating and outputting the pulse synchronous signal according to the noise threshold, the signal-to-noise ratio margin and the coarse frequency measurement signal; obtaining a real part value and an imaginary part value corresponding to the coarse frequency measurement signal according to the coarse frequency measurement signal and the complex frequency spectrums; measuringthe frequency by adopting a phase difference method; and finally, fusing data to output a frequency measurement result. The digital receiver includes the FPGA implementation that integrates the above-described method.

Description

technical field [0001] The invention relates to the communication field, in particular to an FPGA-based instantaneous frequency measurement method and a digital receiver thereof. Background technique [0002] In the radar receiving system, the analog frequency measurement system (IFM) receiver is used to measure the key parameters of the radar pulse signal in real time, such as frequency, amplitude and pulse width. However, due to the inherent limitations of the IFM architecture, the system cannot measure overlapping signals, and the frequency measurement accuracy is low. Contents of the invention [0003] Aiming at the above-mentioned deficiencies in the prior art, the present invention aims to provide an FPGA-based instantaneous frequency measurement method with high frequency measurement accuracy and a digital receiver thereof. [0004] In order to achieve the purpose of above-mentioned invention creation, the technical scheme that the present invention adopts is: [...

AI Technical Summary

Problems solved by technology

However, due to the inherent limitations of the IFM architecture, the system cannot measure overlapping signals, and the frequency measurement accuracy is low

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