| With the rapid development of wireless communication industry and the continuous progress of microelectronics technology,all kinds of wireless communication facilities are widely used,and the spectrum signals in the environment also show the trend of randomness and diversity.In order to make more effective use of the limited spectrum resources and better analyze the complex spectrum signals in the environment,this paper designs an environment spectrum analysis system based on FPGA around the research and development of spectrum analysis system based on FPGA.Firstly,the structure of the three spectrum analyzers is compared and analyzed,and the spectrum analysis system is realized by the structure processing technology of the spectrum analyzers with the zero intermediate frequency.Through the design of the function modules of the whole system,the system is divided into two parts: RF front-end unit and baseband processing unit.According to the scheme design of each function module,Zynq and AD9361 are selected as the core devices,and the whole hardware circuit is designed.Secondly,this paper makes an in-depth analysis of AD9361 chip,studies its internal low-noise amplifier and down-conversion circuit structure,realizes the communication between Zynq and AD9361 through the standard SPI interface communication protocol,and realizes the AD9361 chip control through the configuration of registers.The Zynq system on chip is used as the baseband processing unit.Through the heterogeneous characteristics of Zynq chip,the key configuration of PL and PS data interaction is studied.The logic design of baseband processing unit is realized by using Vivado tool,including data transmission logic based on AXI-bus protocol and logic design of DC bias correction IP core.Based on the logic design of FFT IP core of AXI bus protocol,and using FFT IP core to complete the spectrum measurement,and compare with MATLAB simulation to check the validity and correctness of the experimental results.Finally,the spectrum measurement experiments are carried out for various signals in the environment.Through a series of tests on each module circuit and system,the test index verifies the validity and correctness of the system.In view of the spectrum of various signals in the environment,the paper mainly aimed at 5G NR signal,did 256 QAM demodulation,reached the predetermined requirements.This is of great significance for radio spectrum detection at present. |
