System and method for performing digital demodulation to frequency modulated signal in digital wireless intercom system

A frequency modulation signal, digital wireless technology, applied in the direction of digital transmission system, two-way line system station, transmission system, etc., to achieve the effects of digital processing, compatibility, and enhanced anti-interference ability
CN101184255BActive Publication Date: 2011-05-04HYTERA COMM CORP
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
HYTERA COMM CORP
Publication Date
2011-05-04

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Abstract

The invention relates to a system and a method which demodulates the frequency-modulation signal, which solves the compatibility issue of analog FM demodulation in digital mobile interphone system, comprising the following steps: firstly, sampling the input analog FM signal by data sampling module; secondly, removing carrier of the FM data by carrier removal module; thirdly, analyzing the removedcarrier signal of IQ dual to revivify the modulated signal by baseband analytic module; finally, outputting the final modulated signal by lowpass module. The functions of clock module, carrier removal module, baseband analytic module and lowpass module can be realized by a FPGA. The invention has an advantage of achieving the compatibility of analog FM demodulation and the digital treatment of analog signal in digital mobile interphone system, so as to enhance the signal anti-interference capability.
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Description

technical field

[0001] The present invention relates to digital wireless walkie-talkie technology, more specifically, to a system and method for digitally demodulating FM signals in a digital wireless walkie-talkie system. Background technique

[0002] The DMR (Digital Mobile Radio) standard is a digital trunking standard newly released by the European Communications Standards Association. The DMR standard is dominated by digital wireless systems, but it is also clearly required to be compatible with existing analog wireless systems. Therefore, for the current common FM (frequency modulation) analog modulation and demodulation mode, how to realize it on the DMR-based digital platform will be a technical difficulty that must be overcome in the commercialization of the DMR system.

[0003] In current digital mobile walkie-talkies, FPGA (Field Programmable Logic Gate Array chip) is usually used to implement each functional module, but there is no solution for realizing analog ...

Claims

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