All-digital high-dynamic automatic gain control

Abstract

Automatic gain control (AGC) is unavoidable part of radio receivers. Modern receivers combine analog and digital signal processing. Therefore, the AGC circuits are often implemented partially or completely in the digital domain. This paper presents the design of an all-digital high-dynamic AGC, which is suitable for high-frequency software radio receivers that use baseband signal processing. A circuit is developed which does not contain general-purpose multipliers. The design is given for arbitrary chosen input and output word length, and arbitrary chosen attack and release time. One-channel and two-channel AGC circuits are described and their FPGA implementation is discussed.