Method and device to control the gain of a radio receiver

摘要

An automatic gain control (AGC) method and system for a radio receiver are proposed in which the ACG comprises two AGC loops; a first loop controlling signal gain in the analog portion of the radio receiver, a second loop controlling gain in the digital domain after digitization of the received signal. The analog AGC loop has a slower response time than the digital AGC loop. When applied to a multi-branch diversity receiver, each branch has its own digital AGC loop, but the analog gain can be common to all branches, based on measurement of the analog signal in each branch.

主权项

1. An Automatic Gain Control system for a radio receiver having at least one receiving signal path with an analogue and a digital portion, the Automatic Gain Control system comprising:
at least two Automatic Gain Control loops, wherein at least one first Automatic Gain Control loop comprises a first AGC circuit and is configured to control the gain of at least one analogue signal amplifier located in the analogue portion of the receiver and wherein the first Automatic Gain Control loop has a first cycle time (t1), wherein at least one second Automatic Gain Control loop comprises a second AGC circuit and is configured to control signal amplification of at least one signal processing unit in the digital portion of the receiver and wherein the second Automatic Gain Control loop has a second cycle time (t2); and wherein the second cycle time (t2) is shorter than the first cycle time (t1); and wherein the first AGC circuit controls the gain of the at least one analogue signal amplifier prior to the at least one second automatic gain control loop controlling the digital amplification of the at least one digital signal processing unit.