CN110365615A - Carrier wave frequency deviation estimation device and carrier wave frequency deviation estimation method - Google Patents
Carrier wave frequency deviation estimation device and carrier wave frequency deviation estimation method Download PDFInfo
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- CN110365615A CN110365615A CN201810253255.7A CN201810253255A CN110365615A CN 110365615 A CN110365615 A CN 110365615A CN 201810253255 A CN201810253255 A CN 201810253255A CN 110365615 A CN110365615 A CN 110365615A
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- carrier wave
- frequency deviation
- wave frequency
- deviation estimation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
- H04L2027/0024—Carrier regulation at the receiver end
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
- H04L2027/0024—Carrier regulation at the receiver end
- H04L2027/0026—Correction of carrier offset
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
A kind of carrier wave frequency deviation estimation device includes an echo-cancellation unit, receives signal to one and carries out an Echo cancellation processing, to generate signal after an Echo cancellation；And a carrier wave frequency deviation estimation unit, a carrier wave frequency deviation estimation is carried out according to signal after the Echo cancellation, to generate a carrier wave frequency deviation estimation value.
Description
Technical field
The present invention is related to carrier wave frequency deviation estimation, especially related to a kind of elimination carrier wave frequency deviation estimation of echo in advance.
Background technique
The transmission end and receiving end of communication system are all each provided at least one source oscillation signal (such as quartz oscillation
Device), to provide frequency signal, as the reference of its circuit running.If receiving end is different from the frequency signal frequency of transmission end
When, referred to as carrier frequency shift (abbreviation carrier wave frequency deviation), may cause receiving end can not the letter that issues of correct interpretation transmission end
Number.In order to avoid the above problem, receiving end must first estimate carrier wave frequency deviation to compensate.
Fig. 1 is the block diagram of a known carrier wave frequency deviation estimation device.Carrier wave frequency deviation estimation device 100 includes biquadratic electricity
Road 110, a Fast Fourier Transform (fast Fourier transform, FFT) circuit 120, peak-peak frequency judgement
Circuit 130 and a division circuit 140.Firstly, 110 couples of reception signal R of biquadratic circuit impose biquadratic operation, to generate one or four
Power operation result R4, then, fast Fourier transform circuit 120 is to biquadratic operation result R4Carry out a fast Flourier change
It changes, to generate biquadratic operation result R4Frequency spectrum Z, as shown in Figure 2.Then, peak-peak decision circuitry 130 is from frequency spectrum Z
The peak-peak P found outMAX, and export peak-peak PMAXCorresponding crest frequency Ω, finally, division circuit 140 will
Crest frequency Ω is divided by four operation result as a carrier wave frequency deviation estimation value E.However, penetrating multi-path when receiving signal R
(multipath) it when being transferred to receiving end, receives in signal R and is often mixed with echo (echo), lead to the maximum peak of frequency spectrum Z
Value PMAXCorresponding crest frequency Ω substantially deviates four times of actual carrier frequency deviation, causes carrier wave frequency deviation estimation device 100 wrong
Estimate carrier wave frequency deviation.
Summary of the invention
Therefore, the object of the invention is that providing a kind of carrier wave frequency deviation estimation device for avoiding misestimating carrier wave frequency deviation and side
Method.
The invention discloses a kind of carrier wave frequency deviation estimation devices, include an echo-cancellation unit, receive signal to one and carry out one
Echo cancellation processing, to generate signal after an Echo cancellation；And a carrier wave frequency deviation estimation unit, according to believing after the Echo cancellation
Number carry out a carrier wave frequency deviation estimation, to generate a carrier wave frequency deviation estimation value.
The present invention separately discloses a kind of wave frequency deviation estimation method, carries out an Echo cancellation processing comprising receiving signal to one, with
Generate signal after an Echo cancellation；And a carrier wave frequency deviation estimation is carried out according to signal after the Echo cancellation, to generate a carrier wave
Frequency deviation estimated value.
Detailed description of the invention
Fig. 1 is the block diagram of a known carrier wave frequency deviation estimation device.
Fig. 2 is an example schematic of the frequency spectrum of biquadratic operation result.
Fig. 3 is the block diagram of one carrier wave frequency deviation estimation device of the embodiment of the present invention.
Fig. 4 is the flow chart of one carrier wave frequency deviation estimation method of the embodiment of the present invention.
Fig. 5 is the block diagram of one echo-cancellation unit of the embodiment of the present invention.
Fig. 6 is the flow chart of one method for echo cancellation of the embodiment of the present invention.
Fig. 7 is the block diagram of one carrier wave frequency deviation estimation unit of the embodiment of the present invention.
Fig. 8 is the block diagram of one coefficient generating unit of the embodiment of the present invention.
Fig. 9 is the flow chart of one coefficient production method of the embodiment of the present invention.
Symbol description
100,30 carrier wave frequency deviation estimation device
110,342 biquadratic circuit
120 fast Fourier transform circuits
130,346 peak-peak frequency decision circuitry
140,348 division circuit
32 echo-cancellation units
34 carrier wave frequency deviation estimation units
322 shift registers
324 multiplication units
325 coefficient generating units
326 summer
328 subtracters
322-1~322-N buffer
324-1~324-N multiplier
344 frequency spectrum generation circuits
3252 conjugate units
3254 multiplication units
3256 addition units
3252-1~3252-N conjugator
3254-1~3254-N multiplier
3256-1~3256-N adder
40,60,90 method
R receives signal
RecSignal after Echo cancellation
R4、Rec 4Biquadratic operation result
Z、ZecFrequency spectrum
PMAXPeak-peak
Ω crest frequency
E carrier wave frequency deviation estimation value
ri,ri-1,ri-2,…,ri-NSymbol
w1~wNCoefficient
S product summation
rselSelected symbol
r*i-1,r*i-2,…,r*i-NIt is conjugated symbol
a1~aNCoefficient adjustment value
w1'~wN' coefficient after update
Specific embodiment
Fig. 3 is the block diagram of one carrier wave frequency deviation estimation device 30 of the embodiment of the present invention, and carrier wave frequency deviation estimation device 30 includes
One echo-cancellation unit 32 and a carrier wave frequency deviation estimation unit 34.Fig. 4 is one carrier wave frequency deviation estimation method 40 of the embodiment of the present invention
Flow chart, firstly, echo-cancellation unit 32 to one receive signal R carry out an Echo cancellation processing, to generate an Echo cancellation
Signal Rec (step S410) afterwards；Then, carrier wave frequency deviation estimation unit 34 carries out a carrier frequency according to signal Rec after Echo cancellation
Estimation partially, to generate a carrier wave frequency deviation estimation value E (step S420).
Referring to Fig. 5, Fig. 5 is the block diagram of one echo-cancellation unit 32 of the embodiment of the present invention, in this embodiment, echo
Eliminating unit 32 is for a prewhitening filter (whitening filter), and so the present invention is not limited thereto.Echo-cancellation unit
32 include a shift register 322 (shift register), a multiplication unit 324, a coefficient generating unit 325, one aggregation
Device 326 and a subtracter 328.Fig. 6 is the flow chart of one method for echo cancellation 60 of the embodiment of the present invention.Firstly, shift LD
The storage of device 322 receives multiple symbols (symbols) (step S610) of signal R, for example, shift register 322 includes slow
Storage 322-1~322-N, storage receives signal R respectivelyecSymbol ri-1,ri-2,…,ri-N；Then, multiplication unit 324 includes
Multiplier 324-1~324-N, the symbol r that will be stored in buffer 322-1~322-Ni-1,ri-2,…,ri-NIt is multiplied by respectively and is
Number w1~wN, to obtain product (ri-1*w1),(ri-2*w2),…,(ri-N*wN) (step S620), wherein coefficient w1~wNIt is by being
Number generates unit 325 and is provided, in one embodiment, coefficient w1~wNIt can be a preset value, such as 0, or generated by coefficient single
Member 325 is according to signal R after Echo cancellationecWith the symbol r being stored in shift register 322i-1,ri-2,…,ri-NIt generates；So
Afterwards, above-mentioned multiple product additions are obtained a product summation S (step S630) by summer 326.Finally, subtracter 328 will receive
The selected symbol r of the one of signal RselProduct summation S is subtracted, to generate signal R after Echo cancellationecIn a symbol (step
It S640), can be an adder in 328 implementation of subtracter.
In one embodiment, subtracter 328 is coupled to buffer RN, the selected symbol rselTo be stored in buffer RNSymbol
First ri-N, it is symbol ri-1~ri-NIn the symbol that is received earliest, to eliminate the back echo (Post- in the reception signal
echo).In another embodiment, subtracter 328 is coupled to shift register R1Input terminal, the selected symbol rselIt is next
A symbol ri, to eliminate the pre-echo (Pre-echo) in the reception signal.
Referring to Fig. 7, Fig. 7 is the block diagram of one carrier wave frequency deviation estimation unit 34 of the embodiment of the present invention, in this embodiment,
Carrier wave frequency deviation estimation unit 34 is for a biquadratic carrier wave frequency deviation estimation device, and so the present invention is not limited thereto.Carrier wave frequency deviation estimation
Unit 34 includes a biquadratic circuit 342, a frequency spectrum generation circuit 344, a peak-peak frequency decision circuitry 346, a division
Circuit 348.Firstly, biquadratic circuit 342 from echo-cancellation unit 32 receive Echo cancellation after signal Rec, and to Echo cancellation after
Signal RecBiquadratic operation is imposed, to generate a biquadratic operation result Rec 4.Then, frequency spectrum generation circuit 344 transports biquadratic
Calculate result Rec 4A Fast Fourier Transform is carried out, to generate biquadratic operation result Rec 4Frequency spectrum Zec.Then, peak-peak is sentenced
Deenergizing 346 is from frequency spectrum ZecIn the peak-peak P that finds outMAX, and export peak-peak PMAXCorresponding crest frequency Ω.
Finally, division circuit 348 using crest frequency Ω divided by four operation result as a carrier wave frequency deviation estimation value E.
Next, coefficient producer 325 can be according to signal R after Echo cancellationecWith the symbol being stored in shift register 322
First ri-1,ri-2,…,ri-N, to update coefficient w1~wN.Referring to Fig. 8, Fig. 8 is one coefficient generating unit of the embodiment of the present invention
325 block diagram.Coefficient generating unit 325 includes a conjugate unit 3252, a multiplication unit 3254 and an addition unit
3256.Fig. 9 is the flow chart of one coefficient production method 90 of the embodiment of the present invention.Firstly, conjugate unit 3252 includes conjugator
3252-1~3252-N, respectively by symbol ri-1,ri-2,…,ri-NConjugation is taken, is conjugated symbol r* to generatei-1,r*i-2,…,r*i-N
(step S910)；Then, multiplication unit 3254 includes multiplier 3254-1~3254-N, will be conjugated symbol r* respectivelyi-1,r
*i-2,…,r*i-NIt is multiplied by signal R after Echo cancellationecWith a step-length (step size) (not shown), to generate coefficient adjustment value a1
~aN(step S920), wherein step-length is for adjusting adjusted value a1~aNSize, for example, 0.1, it is visual practical in implementation
Demand Design, specifically, the bigger adjusted value a of step-length1~aNIt is just bigger, every ordered coefficients w1~wNAdjustment amount it is just bigger；Most
Afterwards, addition unit 3256 includes adder 3256-1~3256-N, respectively by coefficient w1~wNIn addition coefficient adjustment a1~aN
Value, to generate coefficient w after update1'~wN' (step S930), for respectively with the symbol in updated shift register 322
ri,ri-1,…,ri-(N-1)It is multiplied, to generate signal R after Echo cancellationecIn next symbol.
It is treated as echo in conclusion first passing through echo-cancellation unit 32 and carrying out Echo cancellation due to receiving signal R and disappears
Except rear signal RecAfterwards, it enters back into carrier wave frequency deviation estimation unit 34 and carries out carrier wave frequency deviation estimation, this means, carrier wave frequency deviation estimation unit 34
Input signal be for signal R after Echo cancellationec, therefore can avoid frequency spectrum ZecPeak-peak PMAXCorresponding crest frequency
Ω causes carrier wave frequency deviation estimation unit 34 to misestimate carrier wave frequency deviation, changes sentence because echo substantially deviates four times of actual carrier frequency deviation
It talks about, the present invention, first to signal R progress Echo cancellation processing is received, can effectively promote carrier wave frequency deviation through echo-cancellation unit 32
The accuracy of estimating apparatus 30.
Claims (13)
1. a kind of carrier wave frequency deviation estimation device, includes:
One echo-cancellation unit receives signal to one and carries out an Echo cancellation processing, to generate signal after an Echo cancellation；And
One carrier wave frequency deviation estimation unit carries out a carrier wave frequency deviation estimation according to signal after the Echo cancellation, to generate a carrier frequency
Inclined estimated value.
2. carrier wave frequency deviation estimation device as described in claim 1, which is characterized in that the echo-cancellation unit is for albefaction filter
Wave device.
3. carrier wave frequency deviation estimation device as claimed in claim 2, which is characterized in that the prewhitening filter includes:
One shift register stores multiple symbols of the reception signal；
One first multiplication unit, by multiple symbol respectively multiplied by multiple coefficients, to generate multiple first products；
One sum unit, by multiple first product addition, to generate a product summation；And
One subtrator carries out an additive operation according to a selected symbol of the product summation and the reception signal, is somebody's turn to do with generating
Signal after Echo cancellation.
4. carrier wave frequency deviation estimation device as claimed in claim 3, which is characterized in that it further includes a coefficient and unit is provided, wherein
The coefficient provides unit and updates multiple coefficient according to signal after the Echo cancellation and multiple symbol, after generating multiple updates
Coefficient.
5. carrier wave frequency deviation estimation device as claimed in claim 3, which is characterized in that the coefficient provides unit and includes:
Multiple symbol is taken conjugation by one conjugate unit, to generate multiple conjugation symbols；
Multiple conjugation symbol is multiplied by signal and a step-length after the Echo cancellation by one second multiplication unit respectively, more to generate
A coefficient adjustment value；And
Multiple coefficient is added multiple coefficient adjustment value, to generate coefficient after multiple update by one addition unit respectively.
6. carrier wave frequency deviation estimation device as claimed in claim 3, which is characterized in that the selected symbol is in multiple symbol
The symbol being received earliest, to eliminate the back echo in the reception signal.
7. carrier wave frequency deviation estimation device as claimed in claim 3, which is characterized in that the selected symbol is for the reception signal
One next symbol, to eliminate the pre-echo in the reception signal.
8. a kind of carrier wave frequency deviation estimation method, includes:
Signal is received to one and carries out an Echo cancellation processing, to generate signal after an Echo cancellation；And
A carrier wave frequency deviation estimation is carried out according to signal after the Echo cancellation, to generate a carrier wave frequency deviation estimation value.
9. carrier wave frequency deviation estimation method as claimed in claim 8, which is characterized in that carry out the Echo cancellation to the reception signal
Processing includes: the step of signal after the Echo cancellation to generate
Store multiple symbols of the reception signal；
By multiple symbol respectively multiplied by multiple coefficients, to generate multiple first products；
By multiple first product addition, to generate a product summation；And
An additive operation is carried out according to a selected symbol of the product summation and the reception signal, to believe after generating the Echo cancellation
Number.
10. carrier wave frequency deviation estimation method as claimed in claim 9, which is characterized in that further include:
Multiple coefficient is updated according to signal after the Echo cancellation and multiple symbol, to generate coefficient after multiple updates.
11. carrier wave frequency deviation estimation method as claimed in claim 10, which is characterized in that according to signal after the Echo cancellation and be somebody's turn to do
Multiple symbols update multiple coefficient, include: the step of coefficient after multiple updates to generate
Multiple symbol is taken into conjugation, to generate multiple conjugation symbols；
The previous symbol of multiple conjugation is multiplied by signal and a step-length after the Echo cancellation respectively, to generate multiple coefficient adjustments
Value；And
Multiple coefficient is added into multiple coefficient adjustment value respectively, to generate coefficient after multiple update.
12. carrier wave frequency deviation estimation method as claimed in claim 9, which is characterized in that the selected symbol is for multiple symbol
In the symbol that is received earliest, to eliminate the back echo in the reception signal.
13. carrier wave frequency deviation estimation method as claimed in claim 9, which is characterized in that the selected symbol is for the reception signal
A next symbol, to eliminate the pre-echo in the reception signal.
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| WO1993017510A1 (en) * | 1992-02-19 | 1993-09-02 | Picturetel Corporation | Feedback level estimator between loudspeaker and microphone |
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| CN104123946A (en) * | 2006-07-31 | 2014-10-29 | 高通股份有限公司 | Systemand method for including identifier with packet associated with speech signal |
| CN106330801A (en) * | 2016-09-19 | 2017-01-11 | 东莞理工学院 | Adaptive convex combination interference cancellation method in ICS on-channel repeater |
| CN107086973A (en) * | 2016-02-16 | 2017-08-22 | 晨星半导体股份有限公司 | Carrier wave frequency deviation estimation device and carrier wave frequency deviation estimation method |
| US20170353201A1 (en) * | 2016-06-07 | 2017-12-07 | Mstar Semiconductor, Inc. | Echo Cancellation Circuit, Receiver Applied to Digital Communication System and Echo Cancellation Method |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1993017510A1 (en) * | 1992-02-19 | 1993-09-02 | Picturetel Corporation | Feedback level estimator between loudspeaker and microphone |
| CN104123946A (en) * | 2006-07-31 | 2014-10-29 | 高通股份有限公司 | Systemand method for including identifier with packet associated with speech signal |
| US20140219370A1 (en) * | 2013-02-06 | 2014-08-07 | Transpacific Ip Management Group Ltd. | Signal processing in a cooperative ofdm communication system |
| CN107086973A (en) * | 2016-02-16 | 2017-08-22 | 晨星半导体股份有限公司 | Carrier wave frequency deviation estimation device and carrier wave frequency deviation estimation method |
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Application publication date: 20191022 |