Automatic gain control method and device

Abstract

The invention discloses an automatic gain control method and an automatic gain control device, which are used for controlling a gain value of a received signal. The method comprises the following step of: at the same time of regulating and converging the gain value, entering a searching mode to additionally change the gain value at least once to make the gain value approximate to a target level according to at least one characteristic value of relation indicating the change of the gain value with time. In another embodiment, the method further comprises the step of: entering a tracking mode to make the regulation period of gain longer than that before in a periodical gain regulation way so as to reduce introduced noise energy in the tracking of signal strength. Therefore, the embodiment of the invention can improve gain convergence speed, further reduce the influence of noises to a communication system in a mobile receiving environment and improve signal receiving efficiency.

Description

technical field [0001] The invention relates to a processing method and a signal receiving device of a received signal. Background technique [0002] Communication systems generally refer to systems that use signal strength or its derivative values ​​for demodulation and decoding, including wired and wireless communication systems, broadcasting and access communication systems. In a general communication system, the signal strength fluctuates under different channels due to the influence of channel characteristics. If the strength of the received signal at the receiving end is adjusted through an automatic gain controller, the received signal can be maintained within a fixed strength range to avoid The receiving end misjudged the message of the received signal. [0003] However, in an actual system, the signal strength adjusted by the automatic gain controller is not perfectly fixed as the above assumption. The Gaussian channel environment is used to illustrate the operati...

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Problems solved by technology

[0005] However, in the mobile channel environment, the automatic gain controller continuously adjusts the signal strength within the symbol cycle time during the process of stably tracking the signal strength change and immediately compensating for the path loss, resulting in the introduction of additional jitter noise and degrading the receiving performance of the receiver.

For example, the existing automatic gain controllers, such as those proposed in U.S. Patent Nos. 7,336,743, 7,295,073, 7,031,409, and 6,574,292, all use the system operating frequency to periodically adjust the gain. In a mobile environment, additional jitter noise is introduced to degrade the performance of the receiver. Receive performance, so it is greatly affected by nonlinear noise and mobile channel

[0006] All in all, in order to improve the gain convergence speed, the existing automatic gain controller cannot effectively take into account the problem of introducing noise when tracking path loss changes, which greatly affects its receiving performance in a mobile environment

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