FSK digital demodulator

A digital demodulator and counter technology, which is applied in the direction of frequency modulation carrier system, etc., can solve the inconvenience of system integration and other problems, and achieve the effect of improving system integration

Inactive Publication Date: 2013-10-09
UNIV OF ELECTRONIC SCI & TECH OF CHINA
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] There are currently various methods for demodulating phase-co

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  • FSK digital demodulator
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Embodiment Construction

[0033] Specific embodiments of the present invention will be described below in conjunction with the accompanying drawings, so that those skilled in the art can better understand the present invention. It should be noted that in the following description, when detailed descriptions of known functions and designs may dilute the main content of the present invention, these descriptions will be omitted here.

[0034] 1. Demodulator principle and structure

[0035] 1. Principle

[0036] Demodulation is a process of information conversion. The most important problem to be solved in this process is how to identify the high and low frequencies of the binary FSK signal and how to synchronize, convert and detect the FSK signal.

[0037] In the FSK digital demodulator of the present invention, the clock counting method is adopted to identify the high and low frequencies of the FSK signal. That is to count through the sampling clock, measure the time between the rising edge of the prev...

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Abstract

The invention provides an FSK digital demodulator specific to FSK signals with continuous phases. sinusoidal waves are converted into square waves through a comparator, the square waves with 2T0 high level duration are output after being shaped by a wave shaping circuit, a sampling clock is counted through a ping-pong counter in the shaped FSK square wave period to acquire a count value Q of each square wave period, identification, synchronization, conversion and error detection for the FSK signals are conducted in a demodulation module of a state machine according to the count value Q, the digital signal 1 or 0 is output, and then the demodulation for the FSK signals is achieved. The counter is used for counting, demodulation is conducted in the state machine according to the count value Q, and hardware can be easily integrated with an FPGA logic circuit and the like, so that the system integration level is improved.

Description

technical field [0001] The invention belongs to the technical field of FSK (frequency shift keying), and more specifically relates to an FSK digital demodulator. Background technique [0002] FSK is the abbreviation of Frequency-shift keying (Frequency-shift keying), which is a modulation and demodulation method that uses different frequencies to represent different information symbols. Because of its relatively simple implementation, good anti-interference performance and transmission speed, it has been widely used in communication. For example, in fixed telephone communication, network cable communication, optical fiber communication and other wireless communication fields. [0003] The commonly used FSK is binary FSK, which uses two frequencies to represent digital signals '0' and '1' respectively. FSK is divided into phase continuous and phase discontinuous from the phase. [0004] Currently, there are various methods for demodulating the phase-continuous binary FSK, ...

Claims

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Application Information

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IPC IPC(8): H04L27/14
Inventor 詹惠琴古军王帅宋洋马良常威
Owner UNIV OF ELECTRONIC SCI & TECH OF CHINA
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