Method and device for auto-gain control of mobile digital multimedia broadcast

Abstract

The invention relates to the field of mobile digital multimedia broadcasting, in particular to an automatic gain control technology of mobile digital multimedia broadcasting. Embodiments of the present invention provide an automatic gain control method and device for mobile digital multimedia broadcasting, which are used to improve the receiving effect of mobile digital multimedia broadcasting. In each designated time slot of the mobile digital multimedia broadcasting, the average power of the received signal is periodically adjusted according to the automatic gain control cycle, and in each automatic gain control cycle, the average power of the received signal is detected according to the signal power detection cycle; and when the automatic gain control When the last detected average power of the received signal in the control cycle is greater than the maximum value of the target range, reduce the average received signal power; when the last detected value in the automatic gain control cycle is smaller than the minimum value of the target range, increase the average received signal power , the automatic gain control period, target range and signal power detection period are determined according to the received signal quality.

Description

technical field [0001] The invention relates to the field of mobile digital multimedia broadcasting, in particular to an automatic gain control technology of mobile digital multimedia broadcasting. Background technique [0002] Mobile digital multimedia broadcasting is a broadcasting system covering a wide range of user terminals. Through satellite and terrestrial wireless broadcasting, it provides small screen, small size, mobile and portable user terminals, such as mobile phones, personal digital assistants (Personal Digital Assistant, PDA), MP3, MP4, digital cameras, notebook computers, etc., receive multimedia broadcasting programs and information services anytime and anywhere. [0003] China Mobile Multimedia Broadcasting (CMMB) is a technical standard for mobile digital multimedia broadcasting proposed by China. The following takes the CMMB system as an example to introduce the receiving system of mobile digital multimedia broadcasting. The length of a radio frame in ...

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Problems solved by technology

[0005] If the automatic gain control is performed in all time slots according to the existing technology, then in the non-designated time slots when the system is closed, since the received signal is 0 when the system is closed, the average power of the received signal will continuously increase under the action of the automatic gain control In some cases, the value of the automatic gain control is out of control; and when the adjustment step of the automatic gain control (Step) is relatively small, the adjustment of the automatic gain control cannot keep up with the fast fading signal changes in the fast fading channel, and when the automatic gain control When the Step is relatively large, the accuracy of the automatic gain control will be relatively poor.

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