CN107707321A - Stereo fm receiver and two-channel separation method - Google Patents
Stereo fm receiver and two-channel separation method Download PDFInfo
- Publication number
- CN107707321A CN107707321A CN201610641283.7A CN201610641283A CN107707321A CN 107707321 A CN107707321 A CN 107707321A CN 201610641283 A CN201610641283 A CN 201610641283A CN 107707321 A CN107707321 A CN 107707321A
- Authority
- CN
- China
- Prior art keywords
- signal
- stereo
- receiver
- difference
- amplitude
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04H—BROADCAST COMMUNICATION
- H04H40/00—Arrangements specially adapted for receiving broadcast information
- H04H40/18—Arrangements characterised by circuits or components specially adapted for receiving
- H04H40/27—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95
- H04H40/36—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95 specially adapted for stereophonic broadcast receiving
- H04H40/45—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95 specially adapted for stereophonic broadcast receiving for FM stereophonic broadcast systems receiving
- H04H40/63—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95 specially adapted for stereophonic broadcast receiving for FM stereophonic broadcast systems receiving for separation improvements or adjustments
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Stereo-Broadcasting Methods (AREA)
- Noise Elimination (AREA)
Abstract
The present invention relates to a kind of stereo fm receiver and two-channel sharing method.The stereo fm receiver includes a fm demodulation unit, for receiving a reception signal, and produces a demodulated signal according to the reception signal；One frequency dividing de-multiplexer, for producing one and signal, a difference signal and a pilot tone amplitude signal according to the demodulated signal；A pair of channel separation unit, for according to difference signal should be weakened with signal and one, producing a left channel output signal and a right channel output signal；And one reduction unit, for weakening the difference signal according to the pilot tone amplitude signal or a signal to noise ratio, to produce the reduction difference signal.
Description
Technical field
The present invention relates to a kind of stereo fm receiver and two-channel separation method is referred to, espespecially one kind can lift left and right
The stereo fm receiver and two-channel separation method of sound channel isolation.
Background technology
Stereo fm (Stereo-Phonic Frequency Modulation) system has been widely used in daily
In life.In general, stereo fm receiver utilizes a pilot signal (Pilot Signal), by a left channel signals and
One right-channel signals are separated from a demodulated signal.In fact, the signal quality of pilot signal may because external environment because
Element and seem faint, or overall signal to noise ratio (Signal to Noise Ratio, SNR) seems not because of external environment factor
It is good, cause stereo fm receiver stereophonic signal can not be moved into fundamental frequency frequency range exactly, and there are a frequency departure
(Frequency Offset), therefore stereo fm receiver can not accurately isolate left channel signals and R channel letter
Number, and reduce left and right acoustic channels isolation.
Therefore, the influence caused by frequency departure how is reduced, further lifting left and right acoustic channels isolation also just turns into industry
One of target that boundary is made great efforts.
The content of the invention
Therefore, the main object of the present invention is that providing a kind of stereo fm for lifting left and right acoustic channels isolation connects
Device and two-channel separation method are received, the shortcomings that to improve known technology.
The present invention discloses a kind of stereo fm (Stereo-Phonic FM) receiver, includes a fm demodulation list
Member, for receiving a reception signal, and a demodulated signal is produced according to the reception signal；One frequency dividing de-multiplexer, for basis
The demodulated signal produces one and signal, a difference signal (Difference Signal) and a pilot tone amplitude signal, wherein should and
Signal is relevant to a left channel signals and a right-channel signals sum, and the difference signal is relevant to the left channel signals and the R channel
The difference of signal；A pair of channel separation unit, should be with signal and a reduction difference signal (Weakened Difference for basis
Signal), a left channel output signal and a right channel output signal are produced；And one reduction unit, be coupled to the frequency dividing solution
Between multiplexer and the two-channel separative element, for weakening (Weaken) difference signal, to produce the reduction difference signal.
The present invention discloses another two-channel separation method, is connect applied to a stereo fm (Stereo-Phonic FM)
Receive device, the two-channel separation method include from the one of stereo fm receiver frequency dividing de-multiplexer receive one and signal,
One difference signal (Difference Signal) and a pilot tone amplitude signal, wherein it should be relevant to a left channel signals with signal
With a right-channel signals sum, the difference signal is relevant to the difference of the left channel signals and the right-channel signals；Shaken according to the pilot tone
Width signal or a signal to noise ratio, (Weaken) difference signal is weakened, to produce a reduction difference signal (Weakened Difference
Signal)；And according to this and signal and the reduction difference signal, produce a left channel output signal and R channel output letter
Number.
Brief description of the drawings
Fig. 1 is the block diagram of the stereo fm receiver of the embodiment of the present invention one.
Fig. 2 is the block diagram that the embodiment of the present invention one weakens unit.
Fig. 3 is the block diagram that the embodiment of the present invention one weakens unit.
Fig. 4 is the schematic diagram of a demodulated signal frequency spectrum.
Fig. 5 is the block diagram that the embodiment of the present invention one divides de-multiplexer.
Fig. 6 is the block diagram of the signal-to-noise ratio computation unit of the embodiment of the present invention one.
Fig. 7 is the block diagram of the fm demodulation unit of the embodiment of the present invention one.
Fig. 8 is the flow chart of a pair of channel separation method of the embodiment of the present invention.
Symbol description
10 stereo fm receivers
100 fm demodulation units
102 frequency dividing de-multiplexers
104 two-channel separative elements
106th, 206,306 reduction unit
108 signal-to-noise ratio computation units
260th, 360 decision package
500 low pass filters
502 bandpass filters
504 mixers
506 low pass filters
508 pilot filters
510 frequency multipliers
512 amplitude units
600th, 608 wave filter
602 subtrators
604 noise energy ratio units
606 magnitude units
610 compare value cell
700 rf filterings and amplifying unit
702 radio frequency mixers
704 intermediate frequency filterings and amplifying unit
706 intermediate frequency mixers
708 demodulating units
80 two-channel separation methods
800~808 steps
A amplitude signals
ApilotPilot tone amplitude signal
AestAmplitude estimated value
C_wkn weakening coefficients
C_sw switch controlling signals
M demodulated signals
nestNoise estimated value
MP multipliers
LO_1, LO_2 oscillator signal
LUT corresponding tables
L_out left channel output signals
R_BPF bandpass filtering results
R_MX smear results
R_out right channel output signals
R reception signals
SNR signal to noise ratio
SW is switched
yIFIntermediate-freuqncy signal
yRFRadiofrequency signal
And signal (L+R)
(L-R) difference signal
(L-R) difference signal ' is weakened
|nest| noise magnitude value
|nave| noise average
Embodiment
Fig. 1 is refer to, Fig. 1 is the block diagram of the stereo fm receiver 10 of the embodiment of the present invention one.Stereo fm connects
Receive device 10 and include a fm demodulation unit 100, one frequency dividing de-multiplexer 102, the reduction unit of a pair of channel separation unit 104, one
106 and a signal-to-noise ratio computation unit 108.Fm demodulation unit 100 receives a reception signal r, and is produced according to reception signal r
An one demodulated signal m and amplitude signal A；Divide de-multiplexer 102 and receive demodulated signal m, and one is produced according to demodulated signal m
With signal (L+R), a difference signal (Difference Signal) (L-R) and a pilot tone amplitude signal Apilot.Signal to noise ratio meter
Calculate unit 108 and receive amplitude signal A, and a signal to noise ratio snr is produced according to amplitude signal A.Wherein, and signal (L+R) is solid
Sound fremodyne 10 receives and is relevant to a left channel signals L and a right-channel signals R sums, and difference signal (L-R) is
Stereo fm receiver 10 receives and is relevant to left channel signals L and right-channel signals R difference.In addition, amplitude signal A systems
Corresponding to a reception signal r amplitude, and pilot tone amplitude signal ApilotCorresponding to a pilot signal (Pilot in demodulated signal m
Signal)xpAn amplitude.
Reduction unit 106 is coupled between frequency dividing de-multiplexer 102 and two-channel separative element 104, for receiving poor letter
Number (L-R), and the energy/amplitude of (Weaken) difference signal (L-R) is weakened, and then produce a reduction difference signal (Weakened
Difference Signal) (L-R) '.Two-channel separative element 104 satisfies basis and signal (L+R) and reduction difference signal
(L-R) an a left channel output signal L_out and right channel output signal R_out, wherein left channel output signal L_ ', are produced
Out is represented by L_out=(L+R)+(L-R) ', and right channel output signal R_out be represented by R_out=(L+R)-
(L-R) '.
Specifically, weakening unit 106 can be according to pilot tone amplitude signal Apilot-Or signal to noise ratio snr produces a weakening coefficient
C_wkn, and difference signal (L-R) is multiplied by weakening coefficient c_wkn, to produce reduction difference signal (L-R) '.It refer to Fig. 2, Fig. 2
The block diagram of unit 206 is weakened for the embodiment of the present invention one.Reduction unit 206 is used for realizing reduction unit 106, and it determines comprising one
The multiplier MP of plan unit 260 and one, decision package 260 can receive pilot tone amplitude signal Apilot-And signal to noise ratio snr, it can root
According to pilot tone amplitude signal Apilot-Or signal to noise ratio snr, weakening coefficient c_wkn is produced, multiplier MP is used for multiplying difference signal (L-R)
With weakening coefficient c_wkn, to produce reduction difference signal (L-R) ', wherein reduction difference signal (L-R) ' is represented by (L-R) '
=c_wkn × (L-R), and weakening coefficient c_wkn value can be between 0 to 1.It is noted that the basis of decision package 260
Pilot tone amplitude signal Apilot-Or signal to noise ratio snr produces weakening coefficient c_wkn mode and unlimited, in an embodiment, when
Pilot tone amplitude signal Apilot-During less than a threshold value TH, it is 0 that decision package 260, which can produce weakening coefficient c_wkn, now left sound
Road output signal L_out and right channel output signal R_out are all and signal (L+R).In another embodiment, decision package
260 can produce weakening coefficient c_wkn according to signal to noise ratio snr, and specifically, decision package 260 can store a corresponding table LUT
(Look Up Table), the corresponding relation of signal to noise ratio snr and weakening coefficient c_wkn is stored in corresponding table LUT, when decision-making list
When member 260 receives signal to noise ratio snr, decision package 260 can find out the reduction corresponding to signal to noise ratio snr from corresponding table LUT
Coefficient c_wkn, and weakening coefficient c_wkn is exported to multiplier MP.The corresponding relation of signal to noise ratio snr and weakening coefficient c_wkn
Visible system demand or actual state and adjusted, and be not limited to specific corresponding relation, for example, refer to Table I, work as letter
Make an uproar when being more than 30dB than SNR, the exportable weakening coefficient c_wkn of decision package 260 is 0.707；When signal to noise ratio snr is less than 18dB
When, the exportable weakening coefficient c_wkn of decision package 260 is 0.054；When signal to noise ratio snr is between 30dB and 18dB, decision-making
The weakening coefficient c_wkn that unit 260 is exported can successively decrease and successively decrease with signal to noise ratio snr.
Table I
It is noted that reduction unit is not limited to realize in a manner of depicted in Fig. 2, it is please further refer to Fig. 3, Fig. 3
The embodiment of the present invention one weakens the block diagram of unit 306.It is similar with reduction unit 206 to weaken unit 306, therefore similar elements are continued to use
Same-sign, unlike reduction unit 206, reduction unit 306 additionally comprises a switch SW, as pilot tone amplitude signal Apilot-
During less than threshold value TH, the one switch controlling signal c_sw of a decision package 360 generation that reduction unit 306 is included to switch
For SW to disconnect (Cutoff), this time difference signal (L-R) can not be transferred to two-channel separative element 104, therefore L channel output letter
Number L_out and right channel output signal R_out is all and signal (L+R)；As pilot tone amplitude signal Apilot-More than threshold value TH
When, decision package 360 produces switch controlling signal c_sw and to switch SW for conducting (Conducted), decision package 360
Weakening coefficient c_wkn is produced according to signal to noise ratio snr, its function mode is similar with decision package 260, is not repeated separately in this.
In addition, signal composition and frequency spectrum on demodulated signal m, details are as follows.For three-dimensional tone display system, (
In the case of ignoring channel response and noise) the demodulated signal m function of time is represented by Wherein L (t) and R (t) represents left channel signals L and right sound respectively
The road signal R function of time, xp(t) it is pilot signal xpThe function of time, pilot signal xp(t) it is represented by Ap、fpAndPilot signal x is represented respectivelyp(t) amplitude, frequency and phase, L (t)+R (t) are represented
With the function of time of signal (L+R), L (t)-R (t) represents difference signal (L-R) function of time.In addition, demodulated signal m (t)
Frequency spectrum can be as shown in figure 4, in general, L (t)+R (t) frequency spectrum be located substantially at 0~15KHz, pilot signal xp(t) frequency
Spectrum is located substantially at 19KHz,Frequency spectrum be located substantially at 23KHz~53KHz.
On dividing the details of de-multiplexer 102, Fig. 5 is refer to, Fig. 5 is that the embodiment of the present invention divides de-multiplexer 102
Block diagram.It is low comprising a low pass filter 500, a bandpass filter 502, a mixer 504, one to divide de-multiplexer 102
Bandpass filter 506, a pilot filter 508, a frequency multiplier 510 and an amplitude unit 512.Low pass filter 500 is used for will
Filtered out positioned at 0KHz~15KHz sum signal L (t)+R (t) from signal m (t), to obtain and signal (L+R).In addition, pilot tone
Wave filter 508 is used for positioned at 19KHz pilot signal xp(t) filtered out from signal m (t), to obtain pilot signal xp, amplitude
Unit 512 receives pilot signal xp, and produce and correspond to pilot signal xpPilot tone amplitude signal Apilot, wherein amplitude unit
512 drill using a CORDIC (Coordinate Rotation Digital Computer, CORDIC)
Algorithm comes according to pilot signal xpObtain pilot tone amplitude signal Apilot, and not limited to this.In addition, bandpass filter 502 is used for inciting somebody to action
23KHz~53KHz signalFiltered out from signal m (t), and produce a bandpass filtering knot
Fruit R_BPF.In addition, divide de-multiplexer 102 and produce vibration pilot signal x using frequency multiplier 510pA frequency-doubled signal
(being located substantially at 38KHz)；Bandpass filtering result R_BPF is multiplied with frequency-doubled signal using mixer 504, to produce a smear knot
Fruit R_MX；The high-frequency components in smear result R_MX are filtered out using low pass filter 506, to obtain difference signal (L-R).Change
Sentence is talked about, and mixer 504 and low pass filter 506 willA fundamental frequency frequency range is moved to, and is taken
Obtain difference signal (L-R).
In addition, the details on signal-to-noise ratio computation unit 108, refer to Fig. 6, Fig. 6 is signal to noise ratio meter of the embodiment of the present invention
Calculate the block diagram of unit 108.Signal-to-noise ratio computation unit 108 includes a wave filter 600, a subtrator 602 and a noise energy
Amount is than unit 604.Wave filter 600 is a low pass filter, for receiving amplitude signal A, and carries out a low pass to amplitude signal A
Filtering/average calculating operation, it can filter out the high-frequency noise composition in amplitude signal A, to produce an amplitude estimated value Aest.Subtraction list
Member 602 is used for amplitude signal A subtracting amplitude estimated value Aest, to produce a noise estimated value nest.Noise energy ratio unit 604
A magnitude unit 606 can be included, a wave filter 608 and one is used for noise estimated value than value cell 610, magnitude unit 606
nestTaken amount level (Magnitude) computing is carried out, to obtain a noise magnitude value | nest|, wave filter 608 is also a low pass filtered
Ripple device, for noise magnitude value | nest| one LPF/average calculating operation is carried out, to obtain a noise average | nave|, than
Value cell 610 receives amplitude estimated value AestAnd noise average | nave|, to calculate signal to noise ratio snr, wherein signal to noise ratio snr can table
It is shown as SNR=| Aest|2/|nave|2.Consequently, it is possible to signal-to-noise ratio computation unit 108 exports the signal to noise ratio snr calculated to weak
Change unit 106, reduction unit 106 can produce weakening coefficient c_wkn according to signal to noise ratio snr.
In addition, the details on fm demodulation unit 100, refer to Fig. 7, Fig. 7 is fm demodulation list of the embodiment of the present invention
The block diagram of member 100.Fm demodulation unit 100 can be a superhet (Superheterodyne Receiver), its
Mixed comprising a rf filtering and amplifying unit 700, a radio frequency mixer 702, an intermediate frequency filtering and amplifying unit 704, an intermediate frequency
The demodulating unit 708 of ripple device 706 and one.Rf filtering and amplifying unit 700 are used for reception signal r in a radio frequency (Radio
Frequency) the signal composition of frequency range filters out from reception signal r comes, and amplifies the signal composition of radio frequency band, to produce one
Radiofrequency signal yRF.Radio frequency mixer 702 will be in radio frequency using one first oscillator signal LO_1 with intermediate frequency filtering and amplifying unit 704
The radiofrequency signal y of frequency rangeRFAn intermediate frequency (Intermediate Frequency) frequency range is moved to, to produce an intermediate-freuqncy signal yIF.Separately
Outside, intermediate frequency mixer 706 utilizes one second oscillator signal LO_2 by the intermediate-freuqncy signal y of intermediate-frequency bandIFA fundamental frequency frequency range is moved to,
Demodulating unit 708 can produce demodulated signal m and amplitude signal A according to this.
It is noted that work as pilot signal xpBad (the i.e. pilot tone amplitude signal A of signal qualitypilot-Less than threshold value
TH when) or signal to noise ratio snr is bad, signalFundamental frequency frequency range can not be moved to exactly, and
It there are a frequency departure.In this case, the present invention is using unit 106 is weakened, in pilot signal xpSignal quality it is bad
Or signal to noise ratio snr it is bad when, in time reduction (or even resistance but) difference signal (L-R), poor to reduce (having frequency departure)
The influence of signal (L-R) pair and signal (L+R), further lift left and right acoustic channels isolation.It is verified by experiments, stereo fm
Receiver 10 can reach 40.6dB left and right acoustic channels isolation, and known stereo fm receiver is only capable of the left and right for reaching 20dB
Sound channel isolation.In other words, stereo fm receiver 10 can reach preferable left and right acoustic channels isolation.
Those skilled in the art, which work as, knows that functional unit/circuit in Fig. 1 to Fig. 3 and Fig. 5 to Fig. 7 can be by digit circuit
Implementation is realized or carried out to (such as RTL circuits) or a digital signal processor (Digital Signal Processor, DSP),
Repeated no more in this.
On the details of operation of stereo fm receiver 10, a pair of channel separation flow can be further summarized as.It please join
Fig. 8 is examined, Fig. 8 is the flow chart of a pair of channel separation of embodiment of the present invention method 80.Two-channel separation method 80 can be by stereo
Fremodyne 10 performs, and two-channel separation method 80 comprises the steps of：
Step 800：Fm demodulation unit 100 produces demodulated signal m according to reception signal r.
Step 802：Divide de-multiplexer 102 according to demodulated signal m produce and signal (L+R), difference signal (L-R) and
Pilot tone amplitude signal Apilot。
Step 804：Unit 106 is weakened according to pilot tone amplitude signal Apilot-Or signal to noise ratio snr, produce weakening coefficient c_
wkn。
Step 806：Difference signal (L-R) is multiplied by weakening coefficient c_wkn by reduction unit 106, to produce reduction difference signal
(L-R) '.
Step 808：The basis of two-channel separative element 104 and signal (L+R) and reduction difference signal (L-R) ', produce left
Channel output signal L_out and right channel output signal R_out.
On the details of operation of two-channel separation method 80, foregoing relevant paragraph is refer to, is not repeated separately in this.
From the foregoing, the present invention can in pilot signal signal quality it is bad or when signal to noise ratio is bad, it is in time weak
Change difference signal, reduce the influence for the difference signal for having frequency departure, further lift left and right acoustic channels isolation.
The foregoing is only presently preferred embodiments of the present invention, all equivalent changes done according to scope of the present invention patent with
Modification, it should all belong to the covering scope of the present invention.
Claims (13)
1. a kind of stereo fm receiver, includes：
One fm demodulation unit, for receiving a reception signal, and a demodulated signal is produced according to the reception signal；
One frequency dividing de-multiplexer, for producing one and signal, a difference signal and a pilot tone amplitude signal according to the demodulated signal,
Wherein should and signal be relevant to a left channel signals and a right-channel signals sum, the difference signal be relevant to the left channel signals and
The difference of the right-channel signals；
A pair of channel separation unit, for according to difference signal should be weakened with signal and one, producing a left channel output signal and one
Right channel output signal；And
One reduction unit, is coupled between the frequency dividing de-multiplexer and the two-channel separative element, for according to the pilot tone amplitude
Signal or a signal to noise ratio, (Weaken) difference signal is weakened, to produce the reduction difference signal.
2. stereo fm receiver as claimed in claim 1, it is characterised in that the reduction unit includes a switch, coupling
It is connected between the frequency dividing de-multiplexer and the two-channel separative element, wherein when the pilot tone amplitude signal is less than a threshold value,
The reduction unit controls this to switch off.
3. stereo fm receiver as claimed in claim 1, it is characterised in that the reduction unit includes：
One decision package, for according to the pilot tone amplitude signal or the signal to noise ratio, producing a weakening coefficient；And
One multiplier, for the difference signal is multiplied by into the weakening coefficient, to produce the reduction difference signal.
4. stereo fm receiver as claimed in claim 3, it is characterised in that when the pilot tone amplitude signal is less than a threshold
During value, the reduction unit produces the weakening coefficient as 0.
5. stereo fm receiver as claimed in claim 3, it is characterised in that the weakening coefficient successively decrease with the signal to noise ratio and
Successively decrease.
6. stereo fm receiver as claimed in claim 3 a, it is characterised in that correspondence is stored in the decision package
Table, the corresponding table store the corresponding relation of the signal to noise ratio and the weakening coefficient.
7. stereo fm receiver as claimed in claim 1, it is characterised in that also comprising a signal-to-noise ratio computation unit, coupling
The fm demodulation unit is connected to, for an amplitude signal according to caused by the fm demodulation unit, calculates the signal to noise ratio, the letter
Make an uproar and include than computing unit：
One wave filter, for receiving the amplitude signal and producing an amplitude estimated value；
One subtrator, for the amplitude signal is subtracted into the amplitude estimated value, to produce a noise estimated value；And
One noise energy ratio unit, for according to the amplitude estimated value and the noise estimated value, calculating the signal to noise ratio.
8. stereo fm receiver as claimed in claim 1, it is characterised in that the fm demodulation unit includes a superhet
Receiver.
9. stereo fm receiver as claimed in claim 1, it is characterised in that the frequency dividing de-multiplexer includes：
One first low pass filter, for receiving the demodulated signal and producing this and signal；
One frequency multiplier, for producing a frequency-doubled signal according to an oscillator signal；
One bandpass filter, for receiving the demodulated signal and producing a bandpass filtering result；
One mixer, for producing a smear result according to the frequency-doubled signal and the bandpass filtering result；
One second low pass filter, for receiving the smear result and producing the difference signal；And
One amplitude unit, for producing the pilot tone amplitude signal according to the pilot signal.
10. a kind of two-channel separation method, applied to a stereo fm receiver, the two-channel separation method includes：
One and signal, a difference signal and pilot tone amplitude letter are received from a frequency dividing de-multiplexer of the stereo fm receiver
Number, wherein it is somebody's turn to do and signal is relevant to a left channel signals and a right-channel signals sum, the difference signal is relevant to L channel letter
Number and the right-channel signals difference；
According to the pilot tone amplitude signal or a signal to noise ratio, the difference signal is weakened, to produce a reduction difference signal；And
According to this and signal and the reduction difference signal, a left channel output signal and a right channel output signal are produced.
11. two-channel separation method as claimed in claim 10, it is characterised in that according to the pilot tone amplitude signal or the noise
Than weakening the difference signal, being included with producing the step of the reduction difference signal：
According to the pilot tone amplitude signal or the signal to noise ratio, a weakening coefficient is produced；And
The difference signal is multiplied by the weakening coefficient, to produce the reduction difference signal.
12. two-channel separation method as claimed in claim 11, it is characterised in that also include：
When the pilot tone amplitude signal is less than a threshold value, the weakening coefficient is produced as 0.
13. two-channel separation method as claimed in claim 11, it is characterised in that the weakening coefficient successively decrease with the signal to noise ratio and
Successively decrease.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610641283.7A CN107707321A (en) | 2016-08-08 | 2016-08-08 | Stereo fm receiver and two-channel separation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610641283.7A CN107707321A (en) | 2016-08-08 | 2016-08-08 | Stereo fm receiver and two-channel separation method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107707321A true CN107707321A (en) | 2018-02-16 |
Family
ID=61169184
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610641283.7A Pending CN107707321A (en) | 2016-08-08 | 2016-08-08 | Stereo fm receiver and two-channel separation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107707321A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111478743A (en) * | 2020-04-20 | 2020-07-31 | 吉林省广播电视研究所(吉林省广播电视局科技信息中心) | Frequency modulation stereo frequency measurement decoding system |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4653095A (en) * | 1986-02-06 | 1987-03-24 | Kahn Leonard R | AM stereo receivers having platform motion protection |
| US5249233A (en) * | 1992-04-06 | 1993-09-28 | Ford Motor Company | Multipath noise minimizer for radio receiver |
| US20040190659A1 (en) * | 2003-03-28 | 2004-09-30 | Raghu Raj | Method and apparatus for signal noise control |
| CN101577851A (en) * | 2009-06-12 | 2009-11-11 | 东南大学 | Method for improving stereo crosstalk |
| US7822211B2 (en) * | 2006-07-12 | 2010-10-26 | Mediatek Inc. | Stereo decoding system capable of reducing the phase shift during the signal transforming |
| TW201136194A (en) * | 2010-04-13 | 2011-10-16 | Newport Media Inc | Pilot based adaptation for FM radio receiver |
| CN102237882A (en) * | 2010-05-06 | 2011-11-09 | 硅实验室公司 | Methods and systems for blending between stereo and mono in a FM receiver |
-
2016
- 2016-08-08 CN CN201610641283.7A patent/CN107707321A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4653095A (en) * | 1986-02-06 | 1987-03-24 | Kahn Leonard R | AM stereo receivers having platform motion protection |
| US5249233A (en) * | 1992-04-06 | 1993-09-28 | Ford Motor Company | Multipath noise minimizer for radio receiver |
| US20040190659A1 (en) * | 2003-03-28 | 2004-09-30 | Raghu Raj | Method and apparatus for signal noise control |
| US7822211B2 (en) * | 2006-07-12 | 2010-10-26 | Mediatek Inc. | Stereo decoding system capable of reducing the phase shift during the signal transforming |
| CN101577851A (en) * | 2009-06-12 | 2009-11-11 | 东南大学 | Method for improving stereo crosstalk |
| TW201136194A (en) * | 2010-04-13 | 2011-10-16 | Newport Media Inc | Pilot based adaptation for FM radio receiver |
| CN102223152A (en) * | 2010-04-13 | 2011-10-19 | 新港传播媒介公司 | Pilot based adaptation for FM radio receiver |
| CN102237882A (en) * | 2010-05-06 | 2011-11-09 | 硅实验室公司 | Methods and systems for blending between stereo and mono in a FM receiver |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111478743A (en) * | 2020-04-20 | 2020-07-31 | 吉林省广播电视研究所(吉林省广播电视局科技信息中心) | Frequency modulation stereo frequency measurement decoding system |
| CN111478743B (en) * | 2020-04-20 | 2021-06-22 | 吉林省广播电视研究所(吉林省广播电视局科技信息中心) | Frequency modulation stereo frequency measurement decoding system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4232862B2 (en) | Noise removal method and noise removal apparatus | |
| US7787630B2 (en) | FM stereo decoder incorporating Costas loop pilot to stereo component phase correction | |
| US20030157914A1 (en) | Radio receiver having an adaptive equalizer and method therefor | |
| US20020142746A1 (en) | Radio receiver having a dynamic bandwidth filter and method therefor | |
| CN104639190B (en) | The AFE(analog front end) system and its processing method of a kind of FM receiver | |
| JP4758592B2 (en) | Broadcast signal receiving apparatus and broadcast signal processing method | |
| US6957054B2 (en) | Radio receiver having a variable bandwidth IF filter and method therefor | |
| CN107040268A (en) | Receiver and communication system | |
| US7292694B2 (en) | Noise reduction in a stereo receiver | |
| JPH11330994A (en) | Measurement of signal quality using fm full-complex detector | |
| US20070213021A1 (en) | Frequency modulation radio receiver including a noise estimation unit | |
| CN107707321A (en) | Stereo fm receiver and two-channel separation method | |
| TWI617202B (en) | Stereo-Phonic FM Receiver and Separation Method for Dual Sound Channels | |
| CN105229928A (en) | The method estimated for signal quality and control and circuit | |
| CN102668387B (en) | The apparatus and method reduced for FM receiver noise and handheld communication devices | |
| CN104618276B (en) | Carrier frequency bias estimation and system in a kind of FM receiver | |
| CN100481896C (en) | Apparatus and method for processing a pilot signal | |
| US8774416B2 (en) | Receiver | |
| JP2004128930A (en) | Fm receiver, and device and method for eliminating noise of fm receiver | |
| JPH0716140B2 (en) | Automatic sound quality control circuit | |
| JP4245243B2 (en) | FM radio receiver signal processing circuit | |
| JPH0279530A (en) | Demodulation circuit for stereo composite signal | |
| JP2009021721A (en) | Fm tuner | |
| JP2005260589A (en) | Stereo demodulator circuit | |
| JP2005269146A (en) | Stereo demodulation circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20180216 |
|
| WD01 | Invention patent application deemed withdrawn after publication |