Method for inhibiting digital frequency-variable image

Abstract

The method uses computer to control the signal source and the spectrum analyzer. The computer is used to generate the test signals (including: frequency, amplitude, spread spectrum and scramble code; the generated test signals are downloaded to the signal source; the signal resource sends the test signals to the digital intermediate frequency board; the digital intermediate frequency board outputs the test signals to the spectrum analyzer; the computer reads out the amplitude at preset frequency point from the spectrum analyzer, and then according to a certain control policy, automatically modifies the parameters in the intermediate frequency board (including: I,Q channel gain of complex modulation, I,Q channel gain of quadrature modulation, DAC offset, fine adjustment gain, and rough adjustment gain) to form a negative feedback channel; gradually controlling the parameters in digital intermediate frequency board to minimize the amplitude of image frequency; when getting the optimal parameter, the obtained the optimal parameter is written into the initialized data in the digital intermediate frequency board.

Description

technical field [0001] The invention relates to the field of software radio, in particular to a digital up-conversion image suppression method. Background technique [0002] In order to solve the intercommunication and interconnection problems between multi-mode and multi-carrier signals in commercial and military radio communications, Joe Mitola first proposed the concept of software radio in May 1992 at the National Conference on Remote Systems in the United States. [0003] Software defined radio (SDR) is a wireless device with a reconfigurable hardware platform, which can span a variety of communication standards. It represents the development trend of almost all radio electronic information systems including wireless communication. The core idea is: 1) the The analog-to-digital converter ADC and the digital-to-analog converter DAC are as close to the antenna as possible; 2) On the basis of fully digitizing the signal, software is used to define as many radio functions a...

AI Technical Summary

Problems solved by technology

[0017] In the communication multi-carrier digital intermediate frequency system, the custom-made SAW filter method is often used, but the cost is high, and the SAW filter has a large difference loss, and an amplifier is often needed later. The important thing is that it cannot fundamentally solve the problem. question

[0018] Improving the layout and routing method has high requirements for the personnel of the hardware PCB (Printed circuit board), and has a lot to do with experience, so the success rate of each layout and routing cannot be guaranteed

[0019] The method of manually adjusting parameters is very time-consuming and laborious, because there are many factors that affect the mirror image, and the weights that affect the mirror amplitude are also different. It is difficult to obtain the best results by manual adjustment, and it is also time-consuming.

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