CN100518155C - Carrier redactor - Google Patents
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- CN100518155C CN100518155C CNB2004100931279A CN200410093127A CN100518155C CN 100518155 C CN100518155 C CN 100518155C CN B2004100931279 A CNB2004100931279 A CN B2004100931279A CN 200410093127 A CN200410093127 A CN 200410093127A CN 100518155 C CN100518155 C CN 100518155C
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Abstract
The invention relates to a carrier reductor. Wherein, correcting distorted phase component led by carrier and Ghost in output signal of feedforward filter, and calculating output signal of feedback filter to avoid distorted phase component and reduce used bit number and prevent hardware number increasing as Tab number increasing.
Description
Technical field
The present invention relates to the carrier redactor of digital playing apparatus, particularly, eliminate the frequency shift (FS) (Frequency offset) and the phase jitter (Phase Jitter) of carrier wave, operation is the passband digital demodulation signal carrier redactor of the digital demodulation function of baseband digital signal.
Background technology
Now, be divided into the integrated system structure that digital broadcast reception technique trend integrated digital that multiple media (radio frequency, wired, satellite) develops is play.
Particularly, be example with the transmission system of HDTV (High-Definition Television), the data with above high bit rate of about 20Mb/s (Bit Rate) by limited frequency band 6MHz transmission, therefore, are needed channel efficiency modulating/demodulating mode preferably.In addition, in order effectively to transmit at noise, service efficiency good channel coding/decoding method, channel equalization (Channel Equalizer) gimmick of symbol/carrier restoring method, multipath (Multi-path) and the Doppler effect non-abnormality characteristics of compensate for channel such as (Doppler) of needs use and reduction symbol and carrier wave.
Comprehensive " many media digital broadcasting receiver " roughly is divided into following 3 kinds of method of reseptances.
1, radio frequency is play receive mode:
Vestigial sideband (VSB:Vestigial Side Band, monolateral band, the Advanced Television standard committee: ATSC, U.S.'s standard)
Orthogonal frequency-division multiplexer (OFDM:Orthogonal Frequency DivisionMultiplexing, double-side band, European standard)
2, cable TV receive mode:
Quadrature amplitude modulation (QAM:Quadrature Amplitude Modulation, double-side band)
3. satellite television receive mode
Orthogonal PSK (QPSK:Quadrature Phase Shift Keying, double-side band)
These 3 kinds of receive modes are constituted with the technology of multiple different factors such as simulation acceptance division, signal Synchronization mode, channel equalization mode, matched filter (Match Filter), channel-decoding mode.
But after, be necessary the function that selection can be shared from the technology of these factors, " the multimedia digital broadcast receiver " that is optimized exploitation.
Generally, " multimedia digital broadcast receiver " constitutes as shown in Figure 1.
The integral body that Fig. 1 plays receiver for existing multimedia digital constitutes schematic diagram, by received RF signal, be converted to the simulation acceptance division 101 of intermediate-freuqncy signal (Intermediate Frequency), utilize A/D (analog/digital) converter section, the digital demodulation portion 102 of the digital signal of demodulation conversion constitutes.
In the above-mentioned simulation acceptance division 101, receive the 50-860MHz radiofrequency signal, be converted to intermediate-freuqncy signal, and be the conversion of signals of this conversion digital signal, be transferred to digital demodulation portion 102 by A/D converter section 101h by tuner 101b.
Described simulation acceptance division 101 comprises: the tuner 101b that the 50-860MHz radiofrequency signal that receives by antenna 101a is converted to 44MHz the 1st intermediate-freuqncy signal; Filter the SAW (Surface Acoustic Wave) filter 101c of above-mentioned tuner 101b output signal; Generate to generate the 1st oscillator 101d of the frequency of oscillation that is used to take place the 2nd intermediate-freuqncy signal; The signal that above-mentioned SAW (Surface Acoustic Wave) filter 101c is filtered carries out down converted with the frequency of oscillation that the 1st oscillator 101d generates, and is converted to the frequency mixer 101e of the 2nd intermediate-freuqncy signal; Compensation is by the automatic gain control amplification 101f of portion of the 2nd intermediate-freuqncy signal gain of above-mentioned frequency mixer 101e output; Generate the 2nd oscillator 101g of sampling frequency; According to the sampling frequency that the 2nd oscillator 101g generates, be the conversion of signals of the above-mentioned automatic gain control amplification 101f of portion amplification the A/D converter section 101h of digital signal.
At this moment, multimedia digital is play in the constituent element of receiver, and simulation acceptance division 101 is irrelevant with demodulation mode, has structure as shown in Figure 1.
On the contrary, digital demodulation portion 102 has various ways according to demodulation mode (VSB, OFDM, QAM, QPSK, ETC), mainly comprises: the symbol reductor; Matched filter; Phase separator; Carrier redactor; Channel equalizer; Channel decoder.
The symbol reductor utilizes resampler, receives the time feedback of current sign, carry out interpolation with the direction of error between the digital signal that reduces above-mentioned A/D converter section 101h output and signal after, export to matched filter.
The symbol reductor carries out the A/D conversion with fixed frequency to analogue data, finish the whole digitized process of the time reduction of all symbol ranks at resampler, therefore, need not other analog element except A/D converter, it is fairly simple to embody this process, and can eliminate the noise of element.
Matched filter filters the signal that above-mentioned symbol reductor carries out sign synchronization output, makes the signal to noise ratio (SNR:Signal to Noise Ratio) of character position reach maximum, adjusts.With the receiving filter is example, in theory, can not realize having the receiving filter of right angle band characteristics and infinitely-great time delay.The testing process that has in the system of these characteristics is quite responsive to small time.So, can avoid influence between the symbol (symbol) in the correct sampling time, if but a point tolerance is arranged, the intersymbol interference phenomenon just takes place.Therefore, for the realization system, need some redundancy bandwidth (Excess Bandwidth).In order to solve problem as mentioned above, use matched filter.
Phase splitter is exported to carrier redactor after the output of above-mentioned matched filter is divided into I signal and Q signal.
When carrier redactor is then eliminated because of the tuner 101a of simulation acceptance division 101 and carrier frequency shift that frequency mixer 101d causes and phase jitter, be the passband digital demodulation signal digital demodulation function of baseband digital signal.
In digital transmission systems such as HDTV (High-Definition Television), the interference that transmission signals causes because of the distortion that generates by multi-path channel or because of NTSC (NTSC system) signal, because of the distortion that transmission and receiving system cause makes the recipient cause that the position detects an error.Particularly, propagate the initiation intersymbol interference, become the main cause that error is detected in the position by the signal of multipath.To this, use channel equalizer to eliminate intersymbol interference.
Transmission system is used the symbol mode of multiple rectification error according to channel circumstance.
Channel circumstance has multiple noises such as burst noise and scattered noise, countermeasure as this noise, channel-decoding portion utilizes RS symbol mode and grid modulation symbol mode, eliminate in the signal that the intersymbol interference of above-mentioned channel equalizer is eliminated, after being present in the burst noise and scattered noise in the channel, the synchronizing signal of inserting during from baseband signal reduction transmission, and utilize above-mentioned synchronizing signal, the data that reduction receives, i.e. transmission symbol.
The carrier redactor that describes in detail in the above-mentioned digital broadcast receiving equipment part is as follows.
The factors such as double image that interference, transmission and the receiving system that double image that the carrier redactor that is used for the HDTV (High-Definition Television) transmission system generates by multi-path channel because of transmission signals or NTSC signal cause causes, the position occurs the recipient and detect error, particularly pass through the signal of multipath and propagate the such function of execution, i.e. compensation causes the main cause of the position detection error of intersymbol interference (ISI:Inter SymbolInterference).
Fig. 2 is the formation schematic diagram that the digital broadcasting receiver of carrier redactor is set, and constitutes with pre-treatment (Pri processing) portion 100 of carrier redactor 200, carrier redactor 200 front ends, the reprocessing portion (Post processing) 300 of carrier redactor 200 rear ends.
Above-mentioned pre-treatment portion 100 is converted to baseband digital signal to passband (Pass Band) digital signal, exports to carrier redactor 200.
Fig. 3 is the structural representation of the carrier redactor 200 of prior art, is made up of feedforward filter 201, feedback filter 202, adder 203 and phase compensator 204.
The present input signal y that above-mentioned feedforward filter 201 receives in above-mentioned pre-treatment portion 100
n=y '
ne
J Φ nElimination from before the error of input, feedback filter 202 from before existing guess value-decision signal of generating of the symbol of detection, i.e. a
n=a '
ne
J Φ nMiddle elimination may generate the part of intersymbol interference.
At this moment, the input signal y of pre-treatment portion 100
n=y '
ne
J Φ nTo be distorted to dependent phase e by carrier phase and dual imaging phase place
J Φ nThe state of size is input to feedforward filter 201, decision signal a
n=a '
ne
J Φ nAlso to distort to e
J Φ nState, be input to feedback filter 202.
Closing of the output signal of the above-mentioned feedforward filter 201 of above-mentioned adder 203 calculating and the output signal of feedback filter 202 exported to phase compensator 204.
That is operation Z,
n* (e
J Φ n)
*Calculate.
Because of Z
n=Z '
ne
J Φ n, aforementioned calculation result is Z '
ne
J Φ n* (e
J Φ n)
*=Z '
n, eliminate the distortion of phase place.
That is the output signal r of above-mentioned phase tracker 204a,
n=Z
ne
-j Φ n=Z '
nCorrect the distortion of phase place, have correct astrology, the output signal of such phase tracker 204a will output to reprocessing portion 300.
Judge that astrology phase compensator 204b is multiplied by the compensation position phase e of judgement astrology/phase compensation/error maker 404c output
J Φ nWith judgement astrology a '
n, generate input signal y with feedforward filter 201
n=y '
ne
J Φ nDecision signal a with identical distortion
n=a '
ne
J Φ n, offer feedback filter 402.
In addition, judge the output signal r of astrology/phase compensation/error maker 404c from phase tracker 204a output
n=Z
ne
-j Φ nGenerate and judge astrology a '
n, a compensation position phase e
J Φ nAnd error guess value e (n).
Above-mentioned judgement astrology a '
nBe not have the composition that phase place is distorted, be input to and judge astrology phase compensator 204b.
Compensation position phase e
J Φ nBe to be input to above-mentioned phase tracker 204a, carry out conjugation and handle, and be multiplied by the output signal Z of adder 203
n=Z '
ne
J Φ n, generate output signal r
n=Z
ne
-j Φ n
In addition, above-mentioned compensation position phase e
J Φ nAlso be input to phase compensator 204b,, be multiplied by above-mentioned judgement astrology a ' at phase compensator 204b
n, generate decision signal a
n=a '
ne
-j Φ n
In addition, error guess value e (n) is input to above-mentioned feedforward filter 201 and feedback filter 202, compensates the input signal y that present feedforward filter 201 receives
n=y '
ne
J Φ nError, eliminate the decision signal a be input to feedback filter 202
n=a '
ne
-j Φ nInitiation symbol (symbol) between the part disturbed.
Such carrier redactor makes the input signal a of feedback filter 202
n=a '
ne
-j Φ nHas input signal y with feedforward filter 201
n=y '
ne
J Φ nSame phase, by phase compensator 203, correct the input signal phase place of feedback filter 202, the certain dual imaging seizures/following function with carrier frequency-phase, dual imaging phase-independent can be provided, and have the strong point that elimination dual imaging ability is provided.
But above-mentioned prior art carrier redactor has following problem:
The input signal y of carrier redactor
n=y '
ne
J Φ nWith because of carrier phase and dual imaging phase place, generate the e that is equivalent to
J Φ nThe state of phase place is input to feedforward filter 201; Be input to the decision signal a of above-mentioned feedback filter 202
n=a '
ne
J Φ nAlso be equivalent to e with distortion
J Φ nState, be input to feedback filter 202.In addition, calculate the output signal Z of the adder of closing 203 of above-mentioned feedforward filter 201 and feedback filter 202
n=Z '
ne
J Φ nAlso keep to distort and be equivalent to e
J Φ nState, with compensation position e mutually
J Φ nConjugate be multiplied by the output signal Z of adder 203
n=Z '
ne
J Φ nAfter, corrected the phase place that causes because of carrier wave and dual imaging by phase tracker 204a and distort.
In order to reduce residual carrier phase and the simultaneous baseband signal of dual imaging phase place, make the decision signal phase place that is input to feedback filter 202 identical with the input signal phase place of feedforward filter 201, what realize this function is exactly phase compensator 204.
That is,, be multiplied by the judgement astrology a ' that does not have phase place to distort at phase compensator 204
nWith compensation position e mutually
J Φ n, it is exported to feedback filter 202, make the decision signal a that is input to feedback filter 202 with this
n=a '
ne
-j Φ nHas same phase with the input signal astrology of feedforward filter 201.
Here, above-mentioned judgement astrology a '
nSignal magnitude 5 (bit) are generally only arranged.If but with judge astrology a '
nBe multiplied by compensation position phase e
J Φ n, be performance compensation position phase e
J Φ n, the position size just is increased to 12.
That is the decision signal a of feedback filter 202 inputs,
n=a '
ne
-j Φ nBe increased to 12, and therefore cause such problem, when realizing, make the input signal of feedback filter 202 use figure place to increase with hardware.Therefore, cause feedback filter 202 to use tabs (TAB) number to increase and the rapid increase of hardware number occurs.
Summary of the invention
The present invention addresses the above problem just, its purpose is, a kind of carrier redactor is provided, can keep the seizure/following function that causes because of carrier frequency-phase and dual imaging phase error of existing carrier redactor support to ISI/ dual imaging channel, and the input signal of minimizing feedback filter uses figure place, and tab (TAB) number of avoiding using because of feedback filter increases the rapid problem that increases of the hardware cost that causes.
To achieve these goals, carrier redactor of the present invention is characterized in that, comprises following part: the feedforward filter of eliminating the error guess value that detects in the former signal from the input signal that comprises the distortion that phase place causes; Eliminate phase place in the guess value of present input signal and distort the feedback filter of eliminating interference between symbol (symbol) in the judgement astrology of composition; Eliminating the phase place of above-mentioned feedforward filter output signal distorts, it is added in the output signal of above-mentioned feedback filter, export to the outside, and generate above-mentioned judgement astrology and error guess value, above-mentioned judgement astrology is offered above-mentioned feedback filter from this external output signal; The error guess value is offered the phase compensator of above-mentioned feedforward filter and feedback filter.
Above-mentioned feedback filter is to eliminate the error guess value that receives from above-mentioned phase compensator from above-mentioned judgement astrology, eliminates with this that to disturb between symbol (symbol) be characteristics.
Above-mentioned phase compensator is to comprise following part: eliminate the phase tracker that phase place is distorted from the output signal of above-mentioned feedforward filter; With the output signal of above-mentioned phase tracker and the output signal addition of above-mentioned feedback filter, and export to outside adder; From above-mentioned adder output signal, generate and to be used for the compensation position phase that phase place that the compensating feedforward filter output signal has is distorted, the judgement astrology of above-mentioned judgement astrology and error guess value/compensation phase/error maker.
Above-mentioned phase tracker is the above-mentioned judgement astrology/compensation position of compensation position phase/error maker output to be carried out conjugation mutually handle, and makes its conjugate that is multiplied by compensation position phase and the output signal of above-mentioned feedforward filter constitute characteristics.
Above-mentioned judgement astrology/compensation position phase/error maker comprises following part: the output signal symbol that extracts above-mentioned adder, generate above-mentioned judgement astrology the symbol extraction device, above-mentioned judgement astrology carried out conjugation handle, and be multiplied by the conjugate of judging astrology and the output signal of adder, generate above-mentioned compensation position phase compensation position phase maker, cut above-mentioned judgement astrology from above-mentioned adder output signal, generate the error maker of above-mentioned error guess value.
Above-mentioned symbol extraction device is to constitute characteristics with flow restricter (Limiter).
Of the present invention constituting by phase tracker 503a, eliminated after the signal phase distortion of feedforward filter 501 receptions, makes its signal that adds that this phase place of elimination is distorted and the output signal of feedback filter 502.
So with the frequency plot and the dual imaging phase-independent of carrier wave, for certain dual imaging seizure/following function is provided, the output signal of feedback filter 502 should have identical astrology with the output signal of above-mentioned phase tracker 503a.That is, the output signal of feedback filter 502 should not have the distortion composition that phase place causes.
Therefore, be input to the signal determining astrology a of feedback filter 502
nIt also should be the correct astrology that does not have phase place to distort.
Because of above-mentioned judgement astrology a
nBe not have the signal that phase place is distorted, can ignore phase place and distort composition that its size only has 5 bits, astrology a is judged in input
nThe input signal of feedback filter 502 use figure place also to reach 5 bits to get final product.
This is input signal use figure place (12 bit) minimizing 7 bit numbers than existing feedback filter, as shown in Figure 7, when realizing with hardware, have such effect, the hardware increment rate that can cause the increase of the use tab (TAB) of feedback filter number is reduced to below half.
Description of drawings
Fig. 1 is the pie graph of existing many media digital broadcasting receiver.
Fig. 2 is that the digital broadcasting receiver that is provided with carrier redactor constitutes schematic diagram.
Fig. 3 is the pie graph of the carrier redactor 200 of prior art.
Fig. 4 is the pie graph of digital broadcasting receiver that is provided with the present invention's carrier redactor.
Fig. 5 is the detailed circuit pie graph of the phase compensator of Fig. 4.
Fig. 6 is a detailed circuit pie graph of judging astrology/phase compensation/error maker.
Fig. 7 is the chart with the several hardware size that change of feedback filter tab (TAB) for relatively more existing carrier redactor and carrier redactor of the present invention.
Accompanying drawing major part symbol description
501: feedforward filter 502: feedback filter
503: phase compensator 503a: phase tracker
503b: adder (Adder) 503c: judge astrology/phase correction/error maker
Embodiment
Other purpose of the present invention and characteristics can describe in detail by the embodiment that the reference accompanying drawing is carried out, and more are expressly understood.
Below with reference to accompanying drawings embodiments of the invention are elaborated.
Fig. 4 is the pie graph of digital broadcasting receiver that is provided with the present invention's carrier redactor, and Fig. 5 is the circuit pie graph of Fig. 4 phase compensator.
Digital broadcasting receiver of the present invention comprises following part as shown in Figure 4 and Figure 5: the pre-treatment portion 400 that the passband digital signal is converted to baseband digital signal; Receive the baseband digital signal that above-mentioned pre-treatment portion 400 generates, and by producing the interference that dual imaging or NTSC signal cause in the channel procedure, transmission and receiving system cause dual imaging, the recipient causes the position and detects error, particularly propagate to cause and disturb (ISI) between symbol (symbol), compensate the carrier redactor 500 that the error main cause is detected in this position by the signal of multipath; The reprocessing portion 600 of carrier redactor 500 rear ends.
At this moment, above-mentioned carrier redactor 500 is with feedforward filter 501 and feedback filter 502 and phase compensator 503 formations.
Above-mentioned feedforward filter 501 is the input signal y of handling part 400 in the past
n=y '
ne
J φ nElimination is from the error of input signal detection before this; Feedback filter 502 is from judging astrology a
nElimination causes the part of disturbing between symbol (symbol).
At this moment, the input signal y of pre-treatment portion 400
n=y '
ne
J φ nThe e that is equivalent to carrier phase and the generation of dual imaging phase place
J φ nState, be input to feedforward filter 501, be input to the judgement astrology a of feedback filter 502
nState there not to be phase place to distort is input to feedback filter 502.
So, the output signal-Z of above-mentioned feedforward filter 501
N1=f
ne
J φ nBe equivalent to e with distortion
J φ nState, be input to phase compensator 503; The output signal Z of feedback filter 502
N2=d
nBe input to phase compensator 503 with the state that does not have phase place to distort.
Above-mentioned phase compensator 504 receives the output signal Z of above-mentioned feedforward filter 501
N1=f
ne
J φ nOutput signal Z with feedback filter 502
N2=d
n, generate output signal r
n=f
n+ d
n, export to reprocessing portion 600, generate the judgement astrology a that does not have phase place to distort
n, offer above-mentioned feedback filter 502.
In addition, generate, offer above-mentioned feedforward filter 501 and feedback filter 502 for the error guess value e (n) that is input to carrier redactor 500 signals.
This phase compensator 504 as shown in Figure 5, by phase tracker 504a and adder 504b, judge astrology/compensation mutually/error maker 504c constitutes.
Above-mentioned phase tracker 504a is to judging the compensation position phase e of astrology/compensation position phase/error maker 404c output
J φ nCarry out conjugation and handle, and be multiplied by the output signal Z of above-mentioned feedforward filter 501
N1=f
ne
J φ n
Promptly carry out Z
N3=Z
N1* (e
J φ n)
*Calculate.
Because of Z
N1=f
ne
J φ n, the result is Z
N3=f
ne
J φ n* (e
J φ n)
*=f
n, the distortion that the output signal of phase tracker 504a causes because of phase place obtains correcting fully, exports correct astrology.
Above-mentioned adder 503b is with the output signal Z of phase tracker 503a
N3=f
nOutput signal Z with feedback filter 502
N2=d
nAddition is output signal r
n=f
n+ d
nExport to reprocessing portion 600.
At this moment, the output signal Z of above-mentioned phase tracker 503a
N3=f
nOutput signal Z with above-mentioned feedback filter 502
N2=d
nAll not having phase place and distort, is the signal with correct astrology, therefore, and output signal r
nDo not have phase place yet and distort, show correct astrology.
In addition, above-mentioned judgement astrology/compensation position phase/error maker 503c is from the output signal r of adder 503b
nGenerate and judge astrology a
nWith compensation position e mutually
J φ nAnd error guess value e (n).
Judge astrology a
nBe signal, be input to above-mentioned feedback filter 502, eliminate by feedback filter 502 and cause the part of disturbing between symbol (symbol) with distortion that phase place causes.
Compensation position phase e
J φ nBe input to phase tracker 503a, carry out conjugation and handle, and be multiplied by the output signal Z of feedforward filter
N1=f
ne
J φ n, generate Z
N3=f
ne
J φ n* (e
-j φ n)
*=f
n
In addition, error guess value e (n) is input to above-mentioned feedforward filter 501 and feedback filter 502, in the past the input signal y of handling part 400 receptions
n=y '
ne
J φ nCompensating error, and from judging astrology a
nElimination causes the part of disturbing between symbol (symbol).
After such carrier redactor is eliminated the signal phase distortion of feedforward filter 501 receptions by phase tracker 503a, the signal of phase place distortion and the output signal addition of feedback filter 502 will be eliminated, therefore, the output signal of feedback filter 502 is different with the output signal of feedforward filter 501, should not have phase place and distort.
The signal composition that is input to feedback filter 502 is judged astrology a
nCan not there be phase place to distort, should has correct astrology.
The judgement astrology a that does not have phase place to distort
nSize with 5 bits.So, be input to and judge astrology a
nThe use figure place of input signal of feedback filter 502 also get final product with regard to 5 bits.
This is that input signal than feedback filter 502 before this uses figure place 12 bits to reduce the numerical value of 7 bits, input signal use figure place minimizing because of feedback filter 502, when realizing, will reduce the hardware increment rate of using tab (TAB) to increase with feedback filter with hardware.
Fig. 6 is a detailed circuit pie graph of judging astrology/compensation position phase/error maker.
As shown in Figure 6, judge that astrology/compensation position phase/error maker 503c constitutes with following part: the output astrology r that extracts adder 503b output
n=f
n+ d
nSymbol, to judge astrology a
nThe symbol extraction device 701 of output, the output signal of above-mentioned symbol extraction device 701 is carried out conjugation handle, and its input signal with symbol extraction device 701 is multiplied by, and generate a compensation phase-e
j φ nCompensation position phase maker 702, deduct the output signal of symbol extraction device 701, the error maker 703 of output error guess value e (n) from the input signal of above-mentioned symbol extraction device 701.
The judgement astrology a of above-mentioned symbol extraction device 701 outputs
nNot having phase place and distort, is the signal with correct astrology (Constellation), will be input to feedback filter 502.
At this moment, above-mentioned symbol extraction device 701 should constitute with flow restricter.
Above-mentioned compensation position generates the compensation position phase e of instrument 702 outputs mutually
J φ nCarry out conjugation with phase tracker 503a and handle, and be multiplied by the signal Z of feedforward filter 501 inputs
N1=f
ne
J φ n
Promptly carry out Z
N1* (e
J φ n)
*Calculating.
Because of Z
N1=f
ne
J φ n, phase tracker 503a exports f
ne
J φ n* (e
J φ n)
*=f
nSignal.
In addition, the error guess value e (n) of above-mentioned error maker 703 outputs is input to above-mentioned feedforward filter 701 and feedback filter 702, and at the error amount that feedforward filter 701 is inferred according to input signal compensation now, feedback filter 702 is according to judging astrology a
nThe error amount that compensation is inferred.
Fig. 7 is the schematic diagram for the hardware size of feedback filter tab (TAB) number of carrier redactor and carrier redactor of the present invention more before this.
According to chart, when the tab of feedback filter (TAB) number was identical, the present invention can reduce the hardware size more than 2 times than prior art.
By above-mentioned description, the related work personnel can carry out various change and modification fully in the scope that does not depart from this invention technological thought.
Therefore, the technical scope of this invention is not limited to the content on the specification, must determine its technical scope according to interest field.
Claims (6)
1, a kind of carrier redactor, its feature comprises:
From have the input signal that phase place distorts, eliminate from before the feedforward filter of error guess value of input;
Eliminate the feedback filter that causes the intersymbol interference part from judge astrology, described judgement astrology is that the guess value of the present input signal of front signal detection is from then on eliminated the signal that phase place is distorted composition;
The phase place of eliminating in the above-mentioned feedforward filter output signal is distorted, and with the output signal addition of above-mentioned feedback filter, export to the outside, and generate above-mentioned judgement astrology and error guess value from this external output signal, above-mentioned judgement astrology is offered above-mentioned feedback filter, and the error guess value is offered the phase compensator of above-mentioned feedforward filter and feedback filter.
2, carrier redactor as claimed in claim 1 is characterized by,
Above-mentioned feedback filter is eliminated the error guess value that above-mentioned phase compensator receives from above-mentioned judgement astrology, eliminates intersymbol interference with this.
3, carrier redactor as claimed in claim 1 is characterized by,
Above-mentioned phase compensator comprises:
From the output signal of above-mentioned feedforward filter, eliminate the phase tracker that phase place is distorted;
The output signal of above-mentioned phase tracker and the output signal of above-mentioned feedback filter are carried out addition, and it is exported to outside adder;
From above-mentioned adder output signal, generate judgement astrology/compensation position phase/error maker of a compensation position phase, above-mentioned judgement astrology and above-mentioned error guess value, described compensation position is to be used for phase place distortion that the compensating feedforward filter output signal has mutually.
4, carrier redactor as claimed in claim 3 is characterized by,
Above-mentioned phase tracker carries out conjugation mutually and handles judging the astrology/compensation position of compensation position phase/error maker output, and is multiplied by the conjugate of compensation position phase and the output signal of above-mentioned feedforward filter.
5, carrier redactor as claimed in claim 3 is characterized by,
Above-mentioned judgement astrology/compensation position phase/error maker comprises:
Extract the output signal symbol of above-mentioned adder, generate the symbol extraction device of above-mentioned judgement astrology;
Conjugation is handled above-mentioned judgement astrology, and will judge that the conjugate of astrology and the output signal of adder multiply each other, thereby generates the compensation position phase maker of above-mentioned compensation position phase;
Deduct above-mentioned judgement astrology from above-mentioned adder output signal, thereby generate the error maker of above-mentioned error guess value.
6, carrier redactor as claimed in claim 5 is characterized by,
Above-mentioned symbol extraction device is made of flow restricter.
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|---|---|---|---|
| CNB2004100931279A CN100518155C (en) | 2004-12-16 | 2004-12-16 | Carrier redactor |
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|---|---|---|---|
| CNB2004100931279A CN100518155C (en) | 2004-12-16 | 2004-12-16 | Carrier redactor |
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| CN103916352B (en) * | 2013-01-06 | 2017-06-16 | 晨星软件研发(深圳)有限公司 | Carrier frequency shift compensation device and method |
| CN107994954B (en) * | 2017-11-28 | 2020-07-31 | 中国电子科技集团公司第五十四研究所 | Orthogonal modulation signal generating device simulating Doppler change |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1464708A (en) * | 2002-06-03 | 2003-12-31 | 矽统科技股份有限公司 | Carrier recovery equipment of digital QAM receiver |
-
2004
- 2004-12-16 CN CNB2004100931279A patent/CN100518155C/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1464708A (en) * | 2002-06-03 | 2003-12-31 | 矽统科技股份有限公司 | Carrier recovery equipment of digital QAM receiver |
Non-Patent Citations (4)
| Title |
|---|
| QAM调制解调系统中载波恢复算法的研究. 刘剑波，牛亚青，王晖.广播与电视技术，第7期. 2002 |
| QAM调制解调系统中载波恢复算法的研究. 刘剑波，牛亚青，王晖.广播与电视技术，第7期. 2002 * |
| 相位处理载波恢复算法研究. 袁清升，刘文.信息与电子工程，第3期. 2003 |
| 相位处理载波恢复算法研究. 袁清升，刘文.信息与电子工程，第3期. 2003 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1791078A (en) | 2006-06-21 |
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