CN1398092A - Frequency-shift keying/Gauss frequency-shift keying signal receiver and its receiving method - Google Patents
Frequency-shift keying/Gauss frequency-shift keying signal receiver and its receiving method Download PDFInfo
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- CN1398092A CN1398092A CN 01120623 CN01120623A CN1398092A CN 1398092 A CN1398092 A CN 1398092A CN 01120623 CN01120623 CN 01120623 CN 01120623 A CN01120623 A CN 01120623A CN 1398092 A CN1398092 A CN 1398092A
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Abstract
This invention relates to a FSK/GFSK signal receiver and its receiving method containing: a FDK/GFSK signal modem receiving transmission signal by an antenna to generate medium frequency (basic frequency) after amplification and filter; an analog digital converter receiving the above mentioned medium (basic) frequencies and convert them to digital signal; a digit frequency distinguisher receiving the above digital signal and generating distinguished signals; a digital band pass filter to filter the HF and DC component of the distinguishing signals to generate modem signals and a quasi-position judgement device receiving modem signal and generating received signals.
Description
Technical field
The present invention relates to the auto frequency offset compensation device, particularly utilize digital filter to come filtering frequency displacement key system (Frequency Shift Keying, FSK)/Gauss frequency-shift keying (GaussianFrequency Shift Keying, GFSK) a kind of frequency-shift keying/Gauss frequency-shift keying (FSK/GFSK) signal receiver and the method for reseptance thereof of the dc voltage that is caused because of frequency offseting value (frequencyoffset) in the demodulator.
Background technology
Because the restriction of size, cost etc., under many occasions, frequency synthesizer (synthesizer), quartz (controlled) oscillator (quartz oscil1ator) or other devices with pinpoint accuracy frequency of oscillation can't be used for producing radio frequency (radio frequency).Therefore, general radio frequency (radio unit) is controlled the frequency shift (FS) of carrying out between transmitting terminal (transmission side) and the receiving terminal (receptionside) (frequency offset) with automatic frequency.
Figure 1 shows that the calcspar of the receiver of general reception FSK/GFSK signal.As shown in the drawing, this receiver 10 comprises an antenna 11, a signal demodulator (signal demodulator) 12, one frequency discriminator (Frequency Discriminator) 13 and one data output unit 14.Signal demodulator 12 is the signal that antenna 11 is received to be filtered amplify, and comprises a band pass filter 121 (band-pass filter), one first amplifier (Amplifier) 122, a mixer (Mixer) 123, an oscillator 124, one second amplifier 125 and an amplitude limiter (Limiter) 126.Antenna 11 receives from the radio-frequency (RF) signal of transmitting terminal (figure does not show) emission, passes to signal demodulator 12 after the generation received signal.Signal demodulator 12 extracts (extract) required frequency range and amplifies back output from received signal.Utilize frequency discriminator 13 to demodulate the signal of being received at last, and via output unit 14 output restituted signals.Yet, in this communication system,, and cause the output unit erroneous judgement because the skew (offset) of carrier wave (carrier) frequency of transmission end and receiving terminal can cause the output signal of frequency discriminator to comprise a direct current deviant.
General FSK/GFSK receiver output unit 14 is the accurate position of direct current that analog low pass filter that employing is made up of resistance 142 and electric capacity 144 is obtained frequency discriminator 13 output signals, again via the output signal of comparator 15 comparison frequency discriminators 13 with accurate of this direct current the generation restituted signal.The output signal of frequency discriminator 13 is charged via buffer 141 and 142 pairs of electric capacity of resistance 144, and by the 143 control charging intervals of control switch, with the accurate position of the direct current of obtaining frequency discriminator 13.Then, control switch 143 is opened (Turn off), utilize voltage that electric capacity 144 the preserved accurate position foundation of device 15 as a comparison, so as to producing correct restituted signal.
But, have several problems can influence the correctness of restituted signal in the above-mentioned output unit 14.At first, the accuracy of the accurate position of the switching time of control switch 143 and obtained direct current has very big influence.The secondth, the size of resistance and electric capacity must be assessed individually according to designed system.The 3rd, diverter switch 143 must be controlled by back level control unit (figure does not show), increases manufacturing cost.
Summary of the invention
Because the problems referred to above the objective of the invention is to propose to utilize the digital filtering unit to filter a kind of frequency-shift keying/Gauss frequency-shift keying (FSK/GFSK) signal receiver and the method for reseptance thereof of the direct current composition that frequency offseting value caused.
For reaching above-mentioned purpose, a kind of frequency-shift keying/Gauss frequency-shift keying of the present invention (FSK/GFSK) signal receiver comprises: a FSK/GFSK signal demodulator is the transmission signal that reception is received from antenna, and amplifies and filtration back generation intermediate frequency (fundamental frequency) signal; One analog-digital converter receives intermediate frequency (fundamental frequency) signal of FSK/GFSK signal demodulator, and converts digital signal to; One digital frequency discriminator receives the digital signal of analog-digital converter, and produces distinguishing signal; One digital band-pass filter, the radio-frequency component and the flip-flop of filtering distinguishing signal, and produce restituted signal; And, surely the position determining device, the receiving demodulation signal also produces received signal.And digital band-pass filter can be connected in series with digital high-pass filter by wave digital lowpass filter and form.Therefore, frequency-shift keying/Gauss frequency-shift keying of the present invention (FSK/GFSK) signal receiver, utilize digital filter circuit that the dc offset of distinguishing signal is filtered, produce a demodulation signal that not influenced by frequency shift (FS) flip-flop, make the accurate position determining device of back level not need the accurate position of direct current of basis signal can correctly judge restituted signal.
Description of drawings
Fig. 1 receives the calcspar of FSK/GFSK signal receiver for prior art;
Fig. 2 is the calcspar of FSK/GFSK signal receiver of the present invention;
Fig. 3 is the embodiment of the part unit of Fig. 2;
Fig. 4 is among Fig. 3, and the output signal of low pass filter is not passed through the waveform of the signal B of digital filter circuit;
Fig. 5 is among Fig. 3, and the output signal of low pass filter is through the waveform of the signal A of digital filter circuit;
Fig. 6 is the flow chart of FSK/GFSK signal receiver of the present invention.
Component parameters symbol description among the figure:
12 signal demodulators
The 20FSK/GFSK signal receiver
21 analog-digital converters
22 digital frequency discriminators
23 finite impulse response (FIR) wave digital lowpass filters
24 infinite impulse response digital filter circuits
A 25 accurate determining device
Embodiment
Describe frequency-shift keying/Gauss frequency-shift keying of the present invention (FSK/GFSK) signal receiver in detail below with reference to accompanying drawing.
Figure 2 shows that the calcspar of FSK/GFSK signal receiver of the present invention.As shown in the drawing, FSK/GFSK signal receiver 20 of the present invention is similar with general FSK/GFSK signal receiver (with reference to figure 1), all comprises antenna 11 and signal demodulator 12.And the framework of these unit and function and general signal receiver (with reference to figure 1) are similar, in this no longer repeat specification.
Except said units, FSK/GFSK signal receiver 20 of the present invention also comprises an analog-digital converter (Analog/Digital Converter, ADC) 21, one digital frequency discriminator (DigitalFrequency Discriminator), 22, one finite impulse response (FIR) wave digital lowpass filter (FiniteImpulse Response Digital Low Pass Filter) 23, one infinite impulse response digital filter (Infinite Impulse Response Digital Filter) 24, and position determining device (slicer) 25 surely.Analog-digital converter 21 receives the signal of signal demodulator 12 and converts this signal to digital signal DS.After this digital signal DS identifies the signal of required frequency via digital frequency discriminator 22, allow desired low-frequency signal pass through, produce first restituted signal by wave digital lowpass filter 23.Then, utilize to produce after the infinite impulse response digital filter 24 filtering flip-flops and do not have second restituted signal of flip-flop.This second restituted signal converts received signal to via accurate position determining device 25.Because second restituted signal that infinite impulse response digital filter 24 produces is not had flip-flop, so an accurate position determining device 25 only needs a comparator 251 to get final product, and the restituted signal of being exported can not be subjected to the influence of direct current offset value and judges by accident.
Fig. 3 is shown as the embodiment of the part unit of Fig. 2.The frequency of Shu Ru intermediate frequency (Inter-medium frequency) signal IF is 1MHz in this embodiment, and has the frequency offseting value of a 150KHz.Symbol unit's speed (symbol rate) of this signal is 1Mbps, and the sample rate of analog-digital converter 21 (sampling rate) fs=32MHz.In addition, the transfer function of finite impulse response (FIR) wave digital lowpass filter 23 is h (z)=h
0+ h
1z
-1+ ... + h
63z
-63, and be 0-0.2MHz by frequency band (pass-band), stop frequency band (stop-band) and be more than the 2M.The prior art that is designed to Digital Signal Processing (Digital Signal Processing) field of the coefficient of h (z) function, method for designing can be with reference to pertinent literatures, or use relevant computer software Aided Design (MATLAB for example
RSignal Processing Toolbox).The Gauss of this finite impulse response (FIR) wave digital lowpass filter 23 (Gaussian) BT Product is 0.5 simultaneously.In addition, the transfer function of infinite impulse response digital filter 24 is
Because the frequency response of digital filter
Can learn that (g (z) is when z=1 and z=-1) its frequency response when frequency f=0Hz and f=16MHz of this digital filter is all 0.Since first restituted signal of this filter of input in the finite impulse response (FIR) wave digital lowpass filter 23 of previous stage with the frequency content filtering more than the 2MHZ, so the actual functional capability of infinite impulse response digital filter 24 is the flip-flop filtering with first restituted signal.In addition, also commutative its sequencing of infinite impulse response digital filter 24 of above-mentioned finite impulse response (FIR) wave digital lowpass filter 23 and filtering flip-flop.Or use the prior art of Digital Signal Processing to design wave digital lowpass filter and the digital high-pass filter that a suitable band pass filter replaces two serial connections, so as to radio-frequency component and the flip-flop in the while filtering distinguishing signal.
Fig. 4 is among Fig. 3 embodiment, the output signal of finite impulse response (FIR) wave digital lowpass filter 23 is not passed through the waveform of the signal B of infinite impulse response digital filter circuit 24, Fig. 5 is among Fig. 3 embodiment, and the output signal of finite impulse response (FIR) wave digital lowpass filter 23 is through the waveform of the signal A of infinite impulse response digital filter circuit 24.Waveform as shown in Figure 4, the output signal of finite impulse response (FIR) wave digital lowpass filter 23 is owing to being subjected to the influence of a 150KHz frequency shift (FS), so produced the dc offset voltage (DC offset) of about 0.4V.The offset voltage of this 0.4V can cause output unit (accurate position determining device 25) erroneous judgement.But, waveform as shown in Figure 5, the output signal of finite impulse response (FIR) wave digital lowpass filter 23 through infinite impulse response digital filter circuit 24 after, cancellation of DC offset voltage.So accurate position determining device 25 can not produce erroneous judgement.
Fig. 6 shows the flow chart of frequency-shift keying/Gauss frequency-shift keying of the present invention (FSK/GFSK) signal method of reseptance.As shown in the drawing, method of reseptance of the present invention roughly is divided into five steps.Below respectively according to the action of this each step of flowchart text:
Step S600: beginning.
Step H602: the signal receiving step receives the transmission signal of receiving from antenna, and amplifies and filtration back generation intermediate frequency (fundamental frequency) signal.
Step S604: the signal switch process converts intermediate frequency (fundamental frequency) signal to digital signal.
Step S606: the signal frequency is differentiated step, the frequency of discriminating digit signal, and produce distinguishing signal.
Step S608: signal filtrating step, filter the radio-frequency component and the low-frequency component of distinguishing signal, and produce restituted signal.
Step S610: judge accurate position step, judge the accurate position of restituted signal and produce received signal.
Step S612: finish.
In step S608, the inventive method is to utilize a band pass filter that the radio-frequency component and the flip-flop of distinguishing signal are filtered.Therefore, the restituted signal that is produced will can not comprise flip-flop, so in the step of the accurate position of the judgement of step S610, can use the accurate position determining device as comparator etc. correctly to produce received signal.And as mentioned above, band pass filter can be connected in series an infinite impulse response digital filter by a finite impulse response (FIR) wave digital lowpass filter and constituted.
Though more than with embodiment the present invention is described, therefore do not limit scope of the present invention, only otherwise break away from main idea of the present invention, the sector person can carry out various distortion or change.
Claims (11)
1. a frequency-shift keying/Gauss frequency-shift keying (FSK/GFSK) signal receiver, it is characterized in that: it comprises:
One receives the transmission signal received from antenna and through amplifying and filter the FSK/GFSK signal demodulator of back generation intermediate frequency (fundamental frequency) signal;
One receives intermediate frequency (fundamental frequency) signal of aforementioned FSK/GFSK signal demodulator and converts the analog-digital converter of digital signal to;
One receives the digital signal of aforementioned analog-digital converter and produces the digital frequency discriminator of distinguishing signal;
One filters the radio-frequency component and the low-frequency component of aforementioned distinguishing signal and produces the digital band-pass filter of restituted signal; And,
One receives aforementioned restituted signal and produces the accurate position determining device of received signal.
2. frequency-shift keying/Gauss frequency-shift keying according to claim 1 (FSK/GFSK) signal receiver is characterized in that: wherein aforementioned digital band-pass filter comprises the wave digital lowpass filter and the digital high-pass filter of serial connection.
3. frequency-shift keying/Gauss frequency-shift keying according to claim 2 (FSK/GFSK) signal receiver is characterized in that: wherein aforementioned wave digital lowpass filter is a finite impulse response (FIR) wave digital lowpass filter.
4. frequency-shift keying/Gauss frequency-shift keying according to claim 2 (FSK/GFSK) signal receiver is characterized in that: wherein aforementioned digital high-pass filter is an infinite impulse response digital filter.
5. a frequency-shift keying/Gauss frequency-shift keying (FSK/GFSK) signal receiver, it is characterized in that: it comprises:
One receives the transmission signal received from antenna and through amplifying and filter the FSK/GFSK signal demodulator of back generation intermediate frequency (fundamental frequency) signal;
One receives intermediate frequency (fundamental frequency) signal of aforementioned FSK/GFSK signal demodulator and converts the analog-digital converter of digital signal to;
One receives the digital signal of aforementioned analog-digital converter and produces the digital frequency discriminator of distinguishing signal;
One filters the radio-frequency component of aforementioned distinguishing signal and produces the wave digital lowpass filter of first restituted signal;
One filters the flip-flop of aforementioned first restituted signal and produces the digital high-pass filter of second restituted signal; And,
One receives aforementioned second restituted signal and produces the accurate position determining device of received signal.
6. frequency-shift keying/Gauss frequency-shift keying according to claim 5 (FSK/GFSK) signal receiver is characterized in that: aforementioned wave digital lowpass filter is a finite impulse response (FIR) wave digital lowpass filter.
7. frequency-shift keying/Gauss frequency-shift keying according to claim 5 (FSK/GFSK) signal receiver is characterized in that: aforementioned digital high-pass filter is an infinite impulse response digital filter.
8. a frequency-shift keying/Gauss frequency-shift keying (FSK/GFSK) signal receiver, it is characterized in that: it comprises:
One receives the transmission signal received from antenna and through amplifying and filter the FSK/GFSK signal demodulator of back generation intermediate frequency signal;
One receives the intermediate frequency signal of aforementioned FSK/GFSK signal demodulator and converts the analog-digital converter of digital signal to;
One receives the digital signal of aforementioned analog-digital converter and produces the digital frequency discriminator of distinguishing signal;
One filters the flip-flop of aforementioned distinguishing signal and produces the digital high-pass filter of first restituted signal;
One filters the radio-frequency component of aforementioned first restituted signal and produces the wave digital lowpass filter of second restituted signal; And
One receives aforementioned second restituted signal and produces the accurate position determining device of received signal.
9. frequency-shift keying/Gauss frequency-shift keying according to claim 8 (FSK/GFSK) signal receiver is characterized in that: aforementioned wave digital lowpass filter is a finite impulse response (FIR) wave digital lowpass filter.
10. frequency-shift keying/Gauss frequency-shift keying according to claim 8 (FSK/GFSK) signal receiver is characterized in that: aforementioned digital high-pass filter is an infinite impulse response digital filter.
11. a frequency-shift keying/Gauss frequency-shift keying (FSK/GFSK) signal method of reseptance is characterized in that: comprise the following step:
Receive signal, receive the transmission signal of receiving from antenna, and produce intermediate frequency (fundamental frequency) signal through amplification and after filtering;
The signal conversion converts aforementioned intermediate frequency (fundamental frequency) signal to digital signal;
The signal frequency is differentiated, differentiates the frequency of aforementioned digital signal, and produces distinguishing signal;
Filtering signals filters the radio-frequency component and the low-frequency component of aforementioned distinguishing signal, and produces restituted signal; And
Judge accurate position, judge the accurate position of aforementioned restituted signal and produce received signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 01120623 CN1221114C (en) | 2001-07-17 | 2001-07-17 | Frequency-shift keying/Gauss frequency-shift keying signal receiver and its receiving method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 01120623 CN1221114C (en) | 2001-07-17 | 2001-07-17 | Frequency-shift keying/Gauss frequency-shift keying signal receiver and its receiving method |
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| Publication Number | Publication Date |
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| CN1398092A true CN1398092A (en) | 2003-02-19 |
| CN1221114C CN1221114C (en) | 2005-09-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 01120623 Expired - Lifetime CN1221114C (en) | 2001-07-17 | 2001-07-17 | Frequency-shift keying/Gauss frequency-shift keying signal receiver and its receiving method |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102386938A (en) * | 2010-09-02 | 2012-03-21 | 瑞昱半导体股份有限公司 | Receiving device of communication system |
| CN101047677B (en) * | 2006-03-31 | 2012-07-04 | 豪威国际控股有限公司 | Low complexity, high performance GFSK signal multi-bit demodulation method |
| CN102857175A (en) * | 2011-06-28 | 2013-01-02 | 联咏科技股份有限公司 | Frame structure supporting zero intermediate frequency/low intermediate frequency/intermediate frequency system and method |
| CN103095621A (en) * | 2012-11-27 | 2013-05-08 | 杭州师范大学 | High speed broadband Frequency Shift Keying (FSK) demodulator circuit |
| CN103152065A (en) * | 2011-12-06 | 2013-06-12 | 北京联拓恒芯科技发展有限公司 | Device and method for modulating signal intermediate frequency digitization receiving |
| US9008206B2 (en) | 2010-08-27 | 2015-04-14 | Realtek Semiconductor Corp. | Receiving apparatus with a single set of channels for processing plural sets of in-phase and quadrature phase signals |
| CN107578612A (en) * | 2016-07-05 | 2018-01-12 | 深圳市芯智科技有限公司 | A kind of 2.4G wireless remote-control systems and method based on drive recorder |
| CN108933748A (en) * | 2017-05-27 | 2018-12-04 | 无锡华润矽科微电子有限公司 | Realize the demodulation method and system of the FM signal of locking frequency variation |
-
2001
- 2001-07-17 CN CN 01120623 patent/CN1221114C/en not_active Expired - Lifetime
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101047677B (en) * | 2006-03-31 | 2012-07-04 | 豪威国际控股有限公司 | Low complexity, high performance GFSK signal multi-bit demodulation method |
| US9008206B2 (en) | 2010-08-27 | 2015-04-14 | Realtek Semiconductor Corp. | Receiving apparatus with a single set of channels for processing plural sets of in-phase and quadrature phase signals |
| CN102386938A (en) * | 2010-09-02 | 2012-03-21 | 瑞昱半导体股份有限公司 | Receiving device of communication system |
| CN102386938B (en) * | 2010-09-02 | 2014-03-05 | 瑞昱半导体股份有限公司 | Receiving device of communication system |
| CN102857175A (en) * | 2011-06-28 | 2013-01-02 | 联咏科技股份有限公司 | Frame structure supporting zero intermediate frequency/low intermediate frequency/intermediate frequency system and method |
| CN103152065A (en) * | 2011-12-06 | 2013-06-12 | 北京联拓恒芯科技发展有限公司 | Device and method for modulating signal intermediate frequency digitization receiving |
| CN103095621A (en) * | 2012-11-27 | 2013-05-08 | 杭州师范大学 | High speed broadband Frequency Shift Keying (FSK) demodulator circuit |
| CN107578612A (en) * | 2016-07-05 | 2018-01-12 | 深圳市芯智科技有限公司 | A kind of 2.4G wireless remote-control systems and method based on drive recorder |
| CN108933748A (en) * | 2017-05-27 | 2018-12-04 | 无锡华润矽科微电子有限公司 | Realize the demodulation method and system of the FM signal of locking frequency variation |
| CN108933748B (en) * | 2017-05-27 | 2020-12-18 | 无锡华润矽科微电子有限公司 | Method and system for demodulating frequency-modulated signal capable of locking frequency change |
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| Publication number | Publication date |
|---|---|
| CN1221114C (en) | 2005-09-28 |
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Granted publication date: 20050928 |