Digital remodulation and digital remodulating method for binary frequency shift keying signal

Abstract

A digital remodulating method of a binary frequency shift key-controlled signal includes converting design of band-pass filter to be design of low-pass filter, not requiring to design various band-pass filters for binary frequency shift key-controlled signal with different central frequency but only requiring to design a type of low-pass filter for binary frequency shift key-controlled signal with the same transmission bandwidth.

Description

technical field [0001] The invention relates to a binary frequency shift keying signal complex modulation complex demodulation method. Background technique [0002] (1). The modulation and demodulation of the traditional binary frequency shift keying (2FSK) signal is usually implemented by real signal processing. Since the frequency shift keying signal is a band-pass signal, for binary frequencies with the same transmission bandwidth but different center frequencies Shift keying signals need to design different band-pass filters (BPF), so it is more cumbersome to implement. [0003] (2). The digital demodulation of the traditional binary frequency shift keying signal generally adopts non-coherent differential demodulation, and there will be a fractional delay in the demodulation process, that is, the delay of the digital signal cannot be exactly the sampling period (sampling The integer multiple of the reciprocal of the rate), the integer multiple delay of the digital signa...

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Problems solved by technology

[0002] (1). The modulation and demodulation of the traditional binary frequency shift keying (2FSK) signal is usually implemented by real signal processing. Since the frequency shift keying signal is a band-pass signal, for binary frequencies with the same transmission bandwidth but different center frequencies Shift keying signal needs to design different band-pass filter (BPF), so it is more cumbersome to implement

[0003] (2). The digital demodulation of the traditional binary frequency shift keying signal generally adopts non-coherent differential demodulation, and there will be a fractional delay in the demodulation process, that is, the delay of the digital signal cannot be exactly the sampling period (sampling The integer multiple of the reciprocal of the rate), the integer multiple delay of the digital signal is very easy to realize, to complete the fractional multiple delay, it must be realized with a single-zero finite impulse response filter (FIR), for different centers The frequency needs to design different single-zero FIR filters. The calculation of the coefficients of this filter is very cumbersome, and the signal processing algorithm is very complicated.

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