Large dynamic fast digital AGC control method

Abstract

The large-dynamic fast digital automatic gain control (AGC) method disclosed by the invention is high in convergence speed, large in dynamic range and short in response time. According to the technical scheme, a digital AGC control circuit divides a channel link of a receiver into a radio frequency part and an intermediate frequency part, in the channel link of the radio frequency part, radio frequency signals pass through a front-end first frequency hopping filter amplification circuit, are subjected to first stepping or superposition attenuation of attenuation through a first numerical control attenuator, are subjected to frequency mixing twice, and then are subjected to second stepping or superposition attenuation through a second numerical control attenuator; the digital AGC radio frequency detection module adjusts radio frequency attenuation and intermediate frequency attenuation in real time according to ADC output, and roughly adjusts link gain; and the second parallel AGC feedback loop controls intermediate-frequency AGC, finely adjusts a link, adjusts the intensity of an intermediate-frequency output signal and controls the output power of the digital automatic gain control loop through an intermediate-frequency gain control module by using intermediate-frequency detection and AD sampling results, thereby completing the whole digital automatic gain control.

Description

technical field [0001] The invention belongs to the field of wireless communication, and relates to a large dynamic fast digital automatic gain control method in a measurement and control and wireless short-wave communication system, which can perform precise gain control on a wide-range radio frequency input signal of a receiver, and output a signal that meets requirements. Background technique [0002] In wireless communication, the communication system is affected by factors such as transmitting power, transmitting and receiving distance, radio wave propagation fading, and electromagnetic environment interference. The signal level received by the receiver is dynamic, and the range exceeds more than 100 dB. However, the signal level range that the receiver can handle is limited, and a signal that is too strong will cause link saturation or blockage; and when the signal is too weak, the carrier-to-noise ratio is too low, so that the A / D cannot sample useful signals. When th...

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Problems solved by technology

[0007] In order to overcome the inability of the traditional analog AGC to quickly and accurately control the wide-range input radio frequency signal, the present invention aims at the shortcomings of the existing technology and provides a large dynamic fast digital AGC with stable circuit, fast convergence speed, large dynamic range and short response time control method

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