An automatic gain control device and method thereof

Abstract

The invention discloses an automatic gain control device and its method. The device includes an analog VGA, an ADC, a downsampling unit and a digital VGA connected in sequence, an analog AGC controller connected with the analog VGA and a digital AGC controller, and a digital VGA controller connected A digital AGC controller, and a power calculation unit connecting the down-sampling unit, the analog AGC controller, and the digital AGC controller. The method comprises: down-sampling the output signal of the analog-to-digital conversion; calculating the power average value of the down-sampled data; calculating the gain coefficient of the analog VGA in the logarithmic domain based on the power average value; using the gain coefficient of the analog VGA to gain the power average value; After averaging the power, calculate the amplitude gain factor. The invention can reduce down-sampling calculation amount and signal distortion, and can also expand the dynamic range of automatic gain, so that the coefficient update time is controllable, there is no problem of loop convergence time, and the consumption of hardware resources is small.

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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