An automatic gain control circuit and control method based on thermometer coding

Abstract

The invention discloses an automatic gain control circuit and a control method based on thermometer coding. The input signal power is calculated through an energy detection module; the difference between the gain adjustment target value and the received signal power value is calculated through the gain control coding module, and a sign bit is extracted. Carry out thermometer coding; convert the gain adjustment code value into a gain control value through the automatic gain control module, which is used to adjust the output of the variable gain amplifier; perform correlation peak detection and identification on the output signal of the automatic gain control module through the frame / symbol capture module The synchronous header of the output signal is used to judge the validity of the signal. The pipeline delay algorithm is used to calculate the input signal power to improve the efficiency of input signal power calculation; the thermometer code is used to encode the gain control value, which improves the reliability of the code and greatly reduces the conversion probability of the analog-to-digital converter for useless signals; adopts equal interval detection The method of length data peak identifies the sync header and improves the robustness of sync header detection.

Description

technical field [0001] The invention belongs to the technical field of high-speed 1553 bus of orthogonal frequency division multiplexing, in particular to an automatic gain control circuit and a control method based on thermometer coding. Background technique [0002] The 1553B bus is a command-response time-division multiple access data bus. Its standard was proposed in 1973 and is still widely used in military, aerospace, industrial and other fields. With the advancement of information technology, the 1Mbps data transmission rate of the traditional 1553B bus has gradually been unable to meet the growing demand for high-speed data transmission. Because the O1553 bus technology can increase the data transmission rate of the traditional 1553B bus from 1Mbps to 100Mbps, is compatible with the network topology of the 1553B bus, and maintains the reliability of the 1553B bus, it has gradually become a focus of research institutions at home and abroad. [0003] The protocol of O...

AI Technical Summary

Problems solved by technology

However, the control of the variable gain amplifier usually needs to dynamically control the gain of the variable gain amplifier based on the result of peak detection of the received signal to meet the signal input level requirements of the analog-to-digital converter. If the signal peak-to-peak value is small, the transient noise The peak of the variable gain amplifier may lead to peak detection error and misoperation of the variable gain amplifier. In addition, since the O1553 signal is modulated by OFDM signal, the gain of the variable gain amplifier changes continuously, which may reduce the linearity of the received signal, resulting in peak-average signal ratio of decline

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