Design of automatic gain control strategy under two-channel model

Abstract

Aiming at the problem that the communication environment is complex and the peak-to-average ratio of the baseband receiving signal of dPMR digital intercom is too large, a strategy for automatic gain control of signals processed by Gaussian channel and Rayleigh channel is proposed. The control strategy adopts feedback DAGC. The structure is optimized based on the moving average detection algorithm and the LSLDAGC gain control algorithm. The signal decision module and the finite gain adjustment mechanism are used to improve the system stability of the processing of the fading signal, and the signal misjudgment rate is reduced. The simulation results show that the AGC system can control the gain of stationary and fading signals with a large dynamic range of 96 dBm, a convergence time of less than 6.25 ms and a sensitivity of -105 dBm. At the same time, it has good stability and tracking performance when the signal power fluctuates.

Keywords

• automatic gain control
• Rayleigh channel
• Gaussian channel
• dPMR protocol