Complete digital logarithm automatic gain control device and method

Abstract

The invention discloses an all-digital logarithm automatic gain control device and a method thereof. A phase shifter extracts an equidirectional branch data I and a quadrature branch data Q of instantaneous outcoming signal, then a power detector obtains the power of outcoming signal, a logarithmic converter performs the linearizing process to the outcoming signal, compares the results with a system preset parameter b to form an error signal, finally an integrator removes the high-frequency component, an index converter performs the reverse-linearizing process to the error signal, a controllable gain amplifier forms a feedback loop. When the outcoming signal power is larger than the preset value,the gain of the controllable gain amplifier is reduced, and when the outcoming signal power is smaller than the preset value,t he gain of the controllable gain amplifier is enhanced, therefore outputting the digit signal with constant power. The invention avoids the limiting amplitude distortion, considerably reduces the complexity of back-end digital signal processing, enhances the anti-interference and stability of the system and effectively reduces the consumption of hardware system resources.

Description

technical field [0001] The invention relates to the field of signal processing, in particular to an all-digital logarithmic automatic gain control device and method. Background technique [0002] With the development of wireless communication technology, we expect more and more signal processing to be converted from the analog domain to the digital domain. In this way, device size and power consumption can be reduced, cost can be reduced, reliability and flexibility can be improved. The ideal all-digital signal processing technology requires that the digitization of analog signals be completed at the radio frequency end RF, thereby completely eliminating analog devices. However, the current technical level is difficult to achieve this goal. [0003] Therefore, in engineering, we first reduce the radio frequency signal RF to the intermediate frequency signal IF, then perform analog-to-digital conversion ADC on the intermediate frequency signal, and finally perform signal pr...

AI Technical Summary

Problems solved by technology

In the previous automatic gain control circuit, the signal power is extracted by down-conversion. This method will occupy a large amount of system resources in actual engineering, increase the complexity of the system, and reduce the stability of the system.

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