Automatic gain control device and method thereof

Abstract

The invention discloses an automatic gain control device and a method thereof. The automatic gain control device comprises a simulation VGA, an ADC, a downsampling unit, a digital VGA, a simulation AGC controller, a digital AGC controller and a power calculating unit, wherein the simulation VGA, the ADC, the downsampling unit and the digital VGA are sequentially connected, the simulation AGC controller is connected with the simulation VGA and the digital AGC controller, the digital AGC controller is connected with the digital VGA, and the power calculating unit is connected with the downsampling unit, the simulation AGC controller and the digital AGC controller. The method comprises the steps of downsampling analog-digital conversion output signals, calculating the power average value for downsampled data, calculating the gain coefficient of the simulation VGA in a logarithm domain based on the power average value, using the gain coefficient of the simulation VGA to gain the power average value, and calculating the amplitude gain coefficient based on the gained power average value. The automatic gain control device can reduce downsampling operation amount and signal distortion, widens an automatic gain dynamic range, enables coefficient updating time to be controllable, solves the problem of loop convergence time and is small in resource consumption of hardware.

Description

technical field [0001] The invention relates to the communication field, in particular to an automatic gain control device and a method thereof. Background technique [0002] In general communication systems, automatic gain control (AGC, Automatic Gain Control) is usually used to adapt the amplitude of the input signal to facilitate subsequent data processing. In the AGC system, signal gain self-adaptation is realized by adjusting an analog variable gain amplifier (AVGA, Analog Variable Gain Amplifier) ​​or a digital variable gain amplifier (DVGA, Digital Variable Gain Amplifier). AVGA acts on the input of the ADC (analog-to-digital converter) to stabilize it near a target value, and try to avoid the phenomenon that the resolution of the digital signal converted by the ADC is too small or saturated. DVGA acts on the input of digital processing to ensure The output signal meets the needs of subsequent digital processing, such as synchronization and demodulation. [0003] In...

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Problems solved by technology

[0006] The purpose of the present invention is to overcome the defects of the prior art and provide an automatic gain control device and its method, which can reduce the amount of down-sampling calculations and signal distortion, and can also expand the dynamic range of automatic gain, so that the coefficient update time is controllable, and the There is a problem of loop convergence time, the structure is simple, and the consumption of hardware resources is small

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