Digital automatic gain control design with large dynamic range in wireless communication receivers

Abstract

Automatic gain control technology is usually adopted to solve the problem of large dynamic range of input signals. Aiming at the challenges existing in digital automatic gain control (DAGC) algorithm, this paper proposes an approximate method based on logarithmic space, and solves the problem of circuit complexity and low dynamic range in traditional DAGC algorithm with the employment of a lookup table. The novel algorithm can change gains of multiple modules on the receiving path at one time, and realize a large dynamic gain control range of 76dB without sacrificing the convergence speed and accuracy. The simulation results show that this new type of DAGC can adjust the overall gain of the receiver rapidly and efficiently according to different input signal amplitudes, and has good engineering practicability with the advantage of simplified circuit.