High-accuracy Frequency Measurement For Use In Digital Receiver Based On FPGA

With FPGA technology moving to high-speed and high-integration direction, it has been widely used in real-time or quasi real-time processing fields.Of the modern electronic warfare receivers, the digital receiver with flexible and diverse algorithm and high-accuracy frequency measurement has become the trend.Therefore, the design concept that using FPGA technology to achieve high-accuracy frequency measurement for use in digital receiver will be of great value and technology strategic significance.This paper studies the frequency measurement techniques of digital receivers based on FPGA. First, the principles of several frequency measurement algorithms are learned with simulation testing in MATLAB. The FFT frequency domain algorithm used in the system is focused on. And on the basis, the software design of the frequency measurement system is completed; Second, in the verification of the accuracy and achievability of the software design, the hardware architecture of the frequency measurement system is analyzed, VHDL language is used to program the various hardware modules which include the IP cores of high-efficiency provided by Altera, the square root operation by the improved nonrestoring square rooting algorithm and the frequency measurement system control module by a state machine. Quartus Ⅱis used to simulate the system with the error frequency under100KHz; Finally, the implementation of FFT algorithm based on FPGA is proposed with Verilog HDL. The principle of the radix-4butterfly algorithm and the laws of the RAM read and write addresses are analyzed. CORDIC algorithm is used to achieve complex multiplication operation. The results of the system show that the system’s performance has reached requirements.