A Fast Automatic Gain Control Method for IF Digital Receiver

Abstract

The invention discloses a fast automatic gain control method for an intermediate frequency digital receiver. Firstly, a posteriori knowledge table of signal strength is obtained to judge the signal strength, and then a posteriori knowledge table of attenuation parameters is obtained, and signals of different strengths are transmitted to a radio frequency front-end device. The AD value of the intermediate frequency output peak value under each attenuation condition is recorded, and used as an attenuation parameter a posteriori knowledge table to query the attenuation level set by the RF front-end device when the AD value of the peak value of a certain intensity signal is within the specified range. When the signal is small, after the first setting and query, the attenuation degree of the RF front-end device will be reduced to perform a setting and query process. But in general, the number of times to be set can be locked within 3 times to realize fast automatic gain control of the receiver.

Description

technical field [0001] The invention relates to the technical field of radio monitoring in a wireless communication system, in particular to a fast automatic gain control method for an intermediate frequency digital receiver. Background technique [0002] With the development of the Internet, the demand for radio communication is also increasing, which also brings pressure on the radio supervision of government departments. In radio monitoring equipment, intermediate frequency digital receivers are widely used. In order to be able to adapt to a wide range of signal strength changes, the receiver usually adds an automatic gain control link to dynamically adjust the attenuation gear of the RF front-end device in the receiver. [0003] The conventional automatic gain control process of the receiver is to continuously adjust the attenuation degree according to the AD sampling value of the peak value of the intermediate frequency signal output by the RF front-end, and finally ma...

AI Technical Summary

Problems solved by technology

For a signal of the same strength, due to the non-linear correlation between the attenuation parameter and the signal peak AD value, when the signal is large or small, the conventional automatic gain control process will include more operations for querying and setting the RF front-end device, while Adjusting the attenuation degree and setting the RF front-end device is a relatively time-consuming process. If this process occurs too many times during an automatic gain control, it will take too much time for an automatic gain control process, which will affect the receiver's overall performance. The scanning speed of the monitoring frequency band affects the timeliness of the output data of the receiver

Images