CN101252557A - Method and apparatus for receiving broadcast signal - Google Patents

Method and apparatus for receiving broadcast signal Download PDF

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Publication number
CN101252557A
CN101252557A CNA2008100856562A CN200810085656A CN101252557A CN 101252557 A CN101252557 A CN 101252557A CN A2008100856562 A CNA2008100856562 A CN A2008100856562A CN 200810085656 A CN200810085656 A CN 200810085656A CN 101252557 A CN101252557 A CN 101252557A
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China
Prior art keywords
signal
frequency
pilot
frame
rotation
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CNA2008100856562A
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Chinese (zh)
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CN101252557B (en
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金泰皓
崔恒硕
李锡范
洪永珍
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LG Electronics Inc
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LG Electronics Inc
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/38—Demodulator circuits; Receiver circuits
    • H04L27/3818—Demodulator circuits; Receiver circuits using coherent demodulation, i.e. using one or more nominally phase synchronous carriers
    • H04L27/3836—Demodulator circuits; Receiver circuits using coherent demodulation, i.e. using one or more nominally phase synchronous carriers in which the carrier is recovered using the received modulated signal or the received IF signal, e.g. by detecting a pilot or by frequency multiplication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/76—Pilot transmitters or receivers for control of transmission or for equalising
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2649—Demodulators
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/36—Modulator circuits; Transmitter circuits
    • H04L27/361—Modulation using a single or unspecified number of carriers, e.g. with separate stages of phase and amplitude modulation

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Circuits Of Receivers In General (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

The invention relates to an apparatus and method for receiving broadcasting signal. The apparatus comprises a first calculator, a DC remover and a second calculator. The first calculator is used for rotating the received signal in frequency domain; the DC remover is used for removing DC component in the signal rotating through frequency; and the second calculator performs frequency rotation to the signal removing DC, enabling the signal removing DC to recover to the original location in the frequency domain.

Description

The method of receiving broadcast signal and the device of receiving broadcast signal
The application requires the priority of the korean patent application 10-2007-0017941 of submission on February 22nd, 2007, incorporates its full content at this into by reference.
Technical field
The present invention relates to be used for the method and apparatus of receiving broadcast signal, relate more specifically to be used for removing the method and apparatus of double pilot from the broadcast singal of emission.
Background technology
Set up China Digital TV broadcasting ground standard in China, it generally is called as digital multimedia/television broadcasting one ground (DMB-T) scheme.The DMB-T scheme can optionally be used signal modulation scheme that is called as Domain Synchronous OFDM (TDS-OFDM) or the single-carrier modulation scheme that transmits via single carrier.
Will the signal of modulation of the transmitting terminal of TDS-OFDM system and emission with Cyclic Prefix OFDM (CP-OFDM) scheme in identical mode be applied to inverse discrete Fourier transformer inverse-discrete (IDFT) scheme, make and transmit above-mentioned signal via a plurality of subcarriers.The sort signal transmission plan is called as multi carrier modulation scheme.
Can also be according to emission (Tx) signal that uses in the above-mentioned single-carrier modulation scheme transmission DMB-T scheme.In other words, the Tx signal multiplexing of DMB-T scheme in first signal and the secondary signal by the single-carrier modulation scheme modulation by the multi carrier modulation scheme modulation, is transmitted into the destination then.
Via the single-carrier modulation scheme of the desired signal of single carrier transmission optionally combined frames make up data, and with double pilot be inserted into constructed data ± 0.5 symbol-rate position.Therefore, the receiver that is used for receiving broadcast signal must use the pilot signal that is inserted into reception (Rx) broadcast singal to come broadcast singal is carried out demodulation, and is necessary for the broadcast singal after the user provides demodulation.
Yet if receiver receives the signal by two kinds of modulation scheme emissions, it must use each modulation scheme to handle received signal.In this case, if receiver is not removed the pilot signal that is included in the frame, then pilot signal other signal in being included in frame is processed, makes beyond thought problem took place in the processing time of broadcast singal.
Summary of the invention
The purpose of this invention is to provide a kind of method and apparatus that is used for receiving broadcast signal, make described method and apparatus can from receive (Rx) broadcast singal, remove or extract double pilot.
For realizing these purposes and other advantage, according to purpose of the present invention, as specifically implement and on broad sense, describe herein, the device that is used for receiving broadcast signal comprises: the receiver that is used for receiving broadcast signal, be used for the broadcast singal that receives is carried out the demodulator of demodulation, be used for the restituted signal of demodulator is carried out balanced equalizer, be used for the error correction unit that the error of transmission of balanced broadcast singal that equalizer is generated is proofreaied and correct, and pilot tone remover, this pilot tone remover is used for the output signal to receiver, the signal that comprises in the frame of any one in the equalizing signal that restituted signal that demodulator generates and equalizer generate carries out the frequency domain rotation, removes pilot signal thus from frame.
The pilot tone remover can comprise first calculator that is used for collecting mail number in frequency domain inward turning switching, be used for from frequency postrotational signal removes the DC remover of direct current (DC) composition and is used for second calculator that the signal after removing DC is carried out the frequency rotation, makes the signal of having removed DC return to residing home position in the frequency domain.
Described received signal can comprise the double pilot signal, and first calculator carries out frequency rotation to the double pilot signal, makes the double pilot signal be positioned at the DC position.
Described DC remover can be a high pass filter.
Described device can also comprise pilot extractor, and the signal that its frame that is used for rotation broadcast singal in frequency domain comprises extracts pilot signal thus from frame.
In another aspect of this invention, the method that is used for receiving broadcast signal comprises: the broadcast singal that receiving broadcast signal and output receive, the broadcast singal that receives is carried out demodulation, broadcast singal after the demodulation is carried out equilibrium, error of transmission to the broadcast singal after the equilibrium is proofreaied and correct, and receive broadcast singal that broadcast singal, output receive and the broadcast singal that receives is carried out the signal exported in arbitrary step of demodulation, and remove the pilot signal that comprises in the frame of the postrotational signal of frequency in frequency domain inward turning switching.
Description of drawings
Accompanying drawing helps to understand better the present invention, and constitutes the application's a part, and accompanying drawing has shown embodiments of the invention, and explains principle of the present invention with specification.Wherein:
Fig. 1 is the block diagram of explanation based on the sender unit of DMB-T scheme;
Fig. 2 is the block diagram of the frame processor that comprises in the sender unit of explanation based on the DMB-T scheme;
Fig. 3 is the structural representation of explanation by the signal frame of DMB-T scheme emission;
Fig. 4 is the block diagram that explanation is used for the device of receiving broadcast signal;
Fig. 5 is the block diagram of explanation pilot extractor and pilot tone remover;
Fig. 6 to 10 shows before removing the frequency spectrum that forms before or after the pilot tone and extracting pilot tone and other frequency spectrum that forms afterwards;
Figure 11 shows the frequency characteristic that pilot tone is removed filter;
Figure 12 shows the frequency characteristic of pilot extraction filter;
Figure 13 to 17 shows each position of pilot tone remover and pilot extractor;
Figure 18 is that the explanation pilot tone is removed the flow chart of handling; And
Figure 19 is the flow chart that the explanation pilot extraction is handled.
Embodiment
Now will be in detail with reference to the preferred embodiments of the present invention, the example is shown in the drawings.
Fig. 1 is the block diagram of explanation based on the sender unit of DMB-T scheme.For the device that is used for receiving broadcast signal is described easily, after this will device that launch broadcast singal according to the DMB-T scheme be described with reference to figure 1.For convenience of description, after this will be called the DMB-T sender unit according to the said apparatus of DMB-T scheme emission broadcast singal.
With reference to figure 1, the DMB-T sender unit comprises that channel encoder 110, system information maker 120, first multiplexer 130, frame head maker 140, frame processor 150, frame form unit 160, filter cell 170 and transmitter unit 180.
110 pairs of armed signals of channel encoder (being the Tx signal) carry out chnnel coding, and the signal behind the delivery channel coding.Channel encoder 110 can use ISN, outer sign indicating number, the method that interweaves and symbol mapped method that the Tx signal is carried out chnnel coding.
System information maker 120 generates the Tx signal system information that comprises Tx signal structure or chnnel coding information, and the Tx signal system information of output generation.Can in system information, define various information, for example, interior code check, interlace mode or the modulation type of Tx signal.
130 pairs of channel encoded signal of first multiplexer and system information signal are carried out multiplexing, export the signal of multiplexing gained then.
The header signal that frame head maker 140 generates as the training signal of echo signal to be launched.The DMB-T scheme uses pseudo noise (PN) sequence as training signal.Frame head maker 130 can generate the PN sequence according to pre-defined rule.
Frame processor 150 receives output signal from first multiplexer 130, handle frame signal (by this frame signal transmission broadcast data), and the signal of gained is handled in output.Each signal segmentation that frame processor 150 comprises in can the frame with the Tx signal becomes to treat by first broadcast singal of single carrier emission and treats by a plurality of subcarriers (promptly, multi-subcarrier) Fa She second broadcast singal can be handled described first and second broadcast singals then.
Frame can comprise via first pattern of single carrier emission and second pattern of launching via multi-subcarrier.To describe with reference to figure 2 and be used to make the method for frame processor 150 according to the corresponding modes processing signals.
Frame forms unit 160 and can carry out multiplexingly to frame signal and frame synchronizing signal, and exports signal after multiplexing.Filter cell 170 can carry out filtering to the bandwidth that frame forms the output signal of unit 160, and the signal of output filtering gained.For example, filter cell 170 uses square root raised cosine (SRRC) filter to prevent inter symbol interference.
The output signal of transmitter unit 180 receiving filter unit 170 is carried out up-conversion to the received signal via radio frequency (RF) transport tape of frequency (fc), then the broadcast singal that generates thus of output.
Fig. 2 is the block diagram of the frame processor that comprises in the sender unit of explanation based on the DMB-T scheme.After this will be with reference to figure 2 descriptor frame body processors 150.
The decomposer 151 that comprises in the frame processor 150 decomposes armed broadcast singal according to each modulating mode, and the signal after decomposing is sent to the first mode treatment unit 155 and the second mode treatment unit 157.
The first mode treatment unit 155 can comprise pretreatment unit 155a and contrary FFT (IFFT) unit 155b.Pretreatment unit 155a carries out frequency interlacing to restituted signal in frequency domain.IFFT unit 155b carries out IFFT to the frequency domain Tx signal of pretreatment unit 155a output, and the signal of output IFFT gained.
The second mode treatment unit 157 can comprise pilot plug-in unit 157a, and it is inserted into pilot signal in the echo signal of transmitting via single carrier (C=1).
Second multiplexer 159 can carry out multiplexing to the output signal of the first and second mode treatment unit 155 and 157, and exports the signal after multiplexing.
Fig. 3 is the structural representation of explanation by the signal frame of DMB-T scheme emission.
With reference to figure 3, frame comprises frame synchronization part and frame.Frame comprises armed data, and frame is as the piece of using discrete Fourier transform (DFT) (DFT).Generally speaking, this piece comprises 3780 flow data units.
Frame synchronization partly comprises one or more PN sequences.The PN sequence that is used for the frame synchronization part can be used the sequence of using m=8 (wherein m=exponent number).If the value of m is 8 (m=8), then can generate 255 different sequences.Each sequence extends to preamble and postamble, makes it can be used for protection at interval.
Preamble and postamble are the cyclic extensions of the recurrence interval of PN sequence with realization PN sequence.
Preceding 115 PN among 255 PN of frame synchronization above-mentioned PN sequence partly are used as postamble, the back of adding 255 PN then to.Back 50 PN of above-mentioned PN sequence are used as preamble, the front of adding 255 PN then to.
If protection is 1/9 at interval, then adds preamble and postamble the front-end and back-end of 255 PN to, thereby constructed the frame synchronization part of forming by 420 data units.In other words, 420 data units make them be used to the frame synchronization part corresponding to 1/9 of 3780 data units of frame piece.The individual data frame comprises frame synchronization part of being made up of 420 data units and the frame of being made up of 3780 data units.
The structure of above-mentioned Frame can change at interval according to protection, and the number of the data unit that comprises in each frame also can change when needed.
And, distribute 1/4 or 1/9 value at interval can for protection.In addition, distribute 1/6 value at interval also can for protection.Therefore, protecting length at interval to form method according to system changes.
Under the situation of single carrier emission mode, double pilot is inserted in the data of frame, and the data transmission that comprises double pilot that is generated is gone out.These data of having inserted pilot tone can be represented by following formula 1:
[formula 1]
y(n)＝x(n)+Pcos(nπ+π) n＝0～3779
Wherein, y (n) is the data of frame, and x (n) is armed coded data, and Pcos (n π+π) is the pilot signal that comprises in the data.
Be used in the method for frame data insertion pilot signal as follows.The data of adding " P (1+j0) " (that is, " P ") to the n=odd number, and the data of will " P (1+j0) " (i.e. " P ") adding the n=even number to.
Fig. 4 is the block diagram that explanation is used for the device of receiving broadcast signal.
With reference to figure 4, the device that is used for receiving broadcast signal comprises tuner 410, frequency filter 420, gain controller 430, analog to digital (A/D) transducer 440, demodulator 450, equalizer 460 and error correction unit 470.For ease of describing and understanding the present invention better, after this tuner 410, frequency filter 420, gain controller 430, A/D converter 440 are called receiver.
Receiver can carry out tuning to the signal of the predetermined frequency band in the broadcast singal, and can export the harmonic ringing with the form configuration of digital signal.
Tuner 410 is selected the signal of predetermined frequency area from the broadcast singal that receives, export selected signal then.
Frequency filter 420 only makes the signal in the desired frequency band pass through, and the other parts outside the desired frequency signal are decayed.Can use surface acoustic wave (SAW) filter as said frequencies filter 420.
Gain controller 430 can be kept the predetermined gain level of signal to be exported.Gain controller 430 uses automatic gain control (AGC) automatically to regulate gain.
A/D converter 440 uses digital signal to simulate the Rx signals sampling, and the signal of output sampling gained.
450 pairs of Rx signals of demodulator carry out demodulation, and the Rx signal after the output demodulation.The channel distortion of 460 pairs of Rx signals of equalizer compensates, and the signal that obtains after the output compensation.
Error correction unit 470 receiving demodulations and balanced data, and carry out error correction to receiving data.Use forward error correction (FEC) as above-mentioned error correcting method.
The pilot tone that is inserted in the single carrier emission mode in the data must be removed from data before arriving error correction unit 470.
Fig. 5 is the block diagram of explanation pilot extractor and pilot tone remover.
With reference to figure 5, pilot tone remover 550 comprises first calculator 510, direct current (DC) remover 520 and second calculator 530.Pilot extractor 560 comprises first calculator 510 and direct current (DC) extractor 540.
After this will describe pilot extractor 560 in detail.
First calculator 510 multiplies each other Rx signal and cos (n π).First calculator 510 alternately multiplies each other Rx signal and " 1 " or " 1 ".For example, the coefficient of cosine function " n " value can be set to alternately repeat the particular value of " 0 " and " 1 ".
The signal of supposing formula 1 expression enters first calculator 510, and " P " and " P " alternately repeats in pilot signal.If value and the pilot signal of cos (n π) multiply each other, then the pilot signal that is generated has the DC composition, and wherein " P " and " P " repeats.
From the viewpoint based on the signal of the Rx of first calculator 510 of frequency, if the value of cos (n π) and above-mentioned Rx signal multiplication, then the signal that is generated is based on the DC position (f=0) of frequency domain and rotate.
DC remover 520 is removed the DC composition from the output signal of first calculator 510.Because from the output signal of first calculator 510, removed the DC composition, therefore can from the Rx signal, remove pilot component by DC remover 520.
For example, DC remover 520 can use high pass filter to realize.DC remover 520 can realize that the enough little frequency removal zone of size is only to remove pilot signal from output signal.
For example, infinite impulse response (IIR) filter can be used as above-mentioned high pass filter.Above-mentioned filter makes current output valve be subjected to the influence of previous output valve.The fundamental formular of above-mentioned filter can be represented by following formula 2:
[formula 2]
y ( n ) = - Σ k = 1 N a k y ( n - k ) + Σ k = 1 N b k x ( n - k )
Wherein " x (n) " is the input value of above-mentioned filter, " y (n) " is the output valve of above-mentioned filter, the above-mentioned filter of " y (n-k) " expression depends on previous output valve, and " n " is the exponent number of above-mentioned filter, and " ak " or " bk " is the exponent number of above-mentioned filter.
Under the situation of the iir filter coefficient of regulating formula 2, can form various filters.Therefore, if regulate exponent number and the coefficient shown in the formula 2, then can form high pass filter with desired characteristic.
Second calculator 530 receives the signal of removing behind the DC from DC remover 520, and the signal and the cos (n π) that will remove behind the DC multiply each other.The value of the cos (n π) that is multiplied each other by second calculator 530 equals the value that multiplied each other by first calculator 510.In other words, from the viewpoint of frequency, second calculator 530 returns to the home position with the rotating signal of first calculator 510.
Based on the angle of frequency from the Rx signal of second calculator 530, if with first calculator 510 in identical mode with value and the above-mentioned Rx signal multiplication of cos (n π), then the signal that is generated is based on the DC position (f=0) of frequency domain and rotate.
The rotating signal of second calculator 530 equals the output signal (that is the signal that, does not have pilot component) of DC remover 520.
To describe pilot extractor 560 in detail below.Pilot extractor 560 comprises first extractor 510 and DC extractor 540.
First calculator 510 multiplies each other input signal and cos (n π), and rotating signal, makes pilot tone be positioned at the DC position by signal rotation.
DC extractor 540 extracts the DC composition from the rotating signal of first calculator 510.Low pass filter can be used as above-mentioned DC extractor 540.DC extractor 540 realize the enough little frequency of sizes by the zone from rotating signal, only to extract pilot signal.
Pilot component is positioned at DC position (f=0) by 510 rotations of first calculator, makes DC extractor 540 to become to assign to obtain pilot component by extract the DC position from postrotational signal.
Infinite impulse response (IIR) filter can be used as low pass filter.Above-mentioned filter makes current output valve be subjected to the influence of previous output valve, and its fundamental formular equals formula 2.
If regulate the exponent number and the coefficient of formula 2, then can form low pass filter with desired characteristic.
Fig. 6 to 10 shows before removing pilot tone and the frequency spectrum that forms afterwards and before extracting pilot tone and other frequency spectrum that forms afterwards.
Fig. 6 to 10 shows the frequency spectrum of (a)～(e) position among Fig. 5 respectively.
Fig. 6 shows the frequency spectrum of input signal of the position " (a) " of Fig. 5.Suppose that this input signal is the data-signal of the frame with pilot tone as shown in Equation 1.
If " n " of above-mentioned input signal is 0, " y (0) " is by y (0)=x (0)+Pcos (π) expression, i.e. y (0)=x (0)-P.For ease of describing, suppose that the frequency spectrum of above-mentioned input signal equals Fig. 6.
Above-mentioned signal is imposed on first calculator 510, multiply each other with cos (n π) then.For example,, " n " is set to odd number, and the pilot tone of above-mentioned input signal is expressed as " P " if " n " is " 1 ".
Fig. 7 shows the frequency spectrum of signal of the position " (b) " of Fig. 5.
The signal of Fig. 7 is imposed on DC remover 520, make DC remover 520 from the signal of Fig. 7, remove the DC composition.The output signal of DC remover 520 is corresponding to the signal of the position " (c) " of Fig. 5, and figure 8 illustrates its frequency spectrum.
The signal of Fig. 8 is imposed on second calculator 530, multiply each other with cos (n π) then.In the mode identical with first calculator 510, " n " of second calculator 530 be " 1 " (n=1).The output signal of second calculator 530 is corresponding to the signal of the position " (d) " of Fig. 5, and figure 9 illustrates its frequency spectrum.
Extracting under the situation of pilot tone, the signal of Fig. 7 is being imposed on DC extractor 540.DC extractor 540 only extracts the DC composition from received signal, and exports the result who is extracted.
The output signal of DC extractor 540 is corresponding to the signal of the position " (e) " of Fig. 5, and figure 10 illustrates its frequency spectrum.
Figure 11 shows the frequency characteristic that pilot tone is removed filter.Figure 12 shows the frequency characteristic of pilot extraction filter.
Pilot tone shown in Figure 11 is removed the pilot tone that filter is removed the DC composition.It is to be positioned near the narrow zone of DC composition that the frequency of above-mentioned filter is removed the zone, and frequency is removed the gain of other frequency field outside the zone near " 1 ".
The filter of Figure 11 uses the iir filter of formula 2 to realize.Under the situation of the filter of Figure 11, " n " be " 2 " (n=2), " a0 " is 1.00000000000000 (a0=1.00000000000000), " a1 " is-2.00000000000000 (a1=-2.00000000000000), " a2 " is 1.00000000000000 (a2=1.00000000000000), " b0 " is 1.00000000000000 (b0=1.00000000000000), " b1 " is 1.99995557117063 (b1=1.99995557117063), and " b2 " is 0.99995557215756 (b2=0.99995557215756).
Pilot extraction filter shown in Figure 12 extracts the pilot tone of DC composition.The frequency of above-mentioned filter is near the narrow zone that is positioned at the DC composition by the zone, and the gain of frequency by other frequency field outside the zone is near " 0 ".
The filter of Figure 12 uses the iir filter of formula 2 to realize.Under the situation of the filter of Figure 12, " n " be " 2 " (n=2), " a0 " is 1.00000000000000 (a0=1.00000000000000), " a1 " is 2.00000000000000 (a1=2.00000000000000), " a2 " is 1.00000000000000 (a2=1.00000000000000), " b0 " is 1.00000000000000 (b0=1.00000000000000), " b1 " is-1.99995557117063 (b1=-1.99995557117063), and " b2 " is 0.99995557215756 (b2=0.99995557215756).
Only be used for illustrative purpose, disclose each coefficient that above-mentioned pilot tone is removed filter and pilot extraction filter, and the filter with above-mentioned characteristic is not limited only to above-mentioned numerical value, also can be set to other value where necessary.
Figure 13 to 17 shows each position according to pilot tone remover of the present invention and pilot extractor.
If receiver carries out channel estimating and channel equalization, then can use protection at interval the PN sequence or be included in pilot tone in the frame.
Can change the use of above-mentioned pilot tone according to receiving position or hardware configuration method.Therefore, the use of pilot extractor or pilot tone remover and position are variable.Yet above-mentioned pilot tone was removed before the Rx signal enters error correction unit.Figure 13 to 17 shows pilot extractor and the pilot tone remover may residing all places.
If demodulator 450 and equalizer 460 do not use the pilot tone that comprises in the frame, then do not use pilot extractor 560.
In this case, only use pilot tone remover 550.As shown in figure 13, pilot tone remover 550 can be positioned at before the demodulator 450.As shown in figure 15, pilot tone remover 550 can be positioned at before the equalizer 460, or as shown in figure 17, it can also be positioned at before the error correction unit 470.
The pilot tone that comprises in using frame comes desired signal is carried out under the situation of demodulation, and pilot tone remover 550 and pilot extractor 560 are positioned at (as shown in figure 14) before the demodulator 450.The pilot tone that comprises in using frame comes desired signal is carried out under the balanced situation, and pilot tone remover 550 and pilot extractor 560 are positioned at (as shown in figure 16) after the equalizer 460.
Figure 18 is that the explanation pilot tone is removed the flow chart of handling.
With reference to Figure 18, at step S910,550 rotations of pilot tone remover receive the frequency of (Rx) signal.By the said frequencies rotation of Rx signal, the double pilot that is included in the Rx signal is positioned at the DC position.
In step S912, remove the DC composition of said frequencies rotating signal.High pass filter can be used for removing the DC composition.High pass filter has the enough little frequency of size and removes the zone, makes it can only remove pilot tone.
At step S914, the signal of having removed DC is carried out the frequency rotation once more, make the signal that generates thus return to the home position.In this case, the rotation of the frequency of S914 is commonly referred to as the frequency derotation.The signal that recovers is the data-signal with pilot component.
Figure 19 is the flow chart that explanation is handled according to pilot extraction of the present invention.
With reference to Figure 19, at step S920, pilot extractor 560 rotations receive the frequency of (Rx) signal.By the above-mentioned rotation of Rx signal, the double pilot that is included in the Rx signal is positioned at the DC position.
In step S922, extract the DC composition of said frequencies rotating signal.Low pass filter can be used for extracting the DC component.Low pass filter has the enough little frequency of size by the zone, makes it can only extract pilot tone.
It should be noted that among the present invention that disclosed most of terms consider functions of the present invention and define, and can or use practice and differently determine according to those skilled in the art's intention.Therefore, be preferably based among the present invention disclosed full content and understand above-mentioned term.
As mentioned above, double pilot be removed or be extracted to the method and apparatus that is used for receiving broadcast signal according to the present invention can from the Rx broadcast singal.
To those skilled in the art, clearly, can make various modifications and variations and not depart from the spirit or scope of the present invention the present invention.Thereby the present invention is intended to cover the modifications and variations of the present invention in the scope that falls into claims and their equivalent.

Claims (15)

1. device that is used for receiving broadcast signal, this device comprises:
The receiver that is used for receiving broadcast signal;
Be used for the received signal of described receiver is carried out the demodulator of demodulation;
Be used for the restituted signal of described demodulator is carried out balanced equalizer;
Be used for the error correction unit that the error of transmission of balanced broadcast singal that described equalizer is generated is proofreaied and correct; And
The pilot tone remover, the signal that is used for comprising in any one the frame of equalizing signal that restituted signal that the output signal to described receiver, described demodulator generate and described equalizer generate carries out the frequency domain rotation, removes pilot signal thus from frame.
2. device according to claim 1, wherein said pilot tone remover comprises:
Be used for first calculator of collecting mail number in frequency domain inward turning switching;
Be used for removing the DC remover of direct current DC composition from the postrotational signal of frequency; And
Second calculator, it is used for the signal behind the removal DC is carried out the frequency rotation, makes that the signal behind the removal DC returns to residing home position in the frequency domain.
3. device according to claim 2, wherein:
Described received signal comprises the double pilot signal, and
Described first calculator carries out the frequency rotation to this double pilot signal, makes this double pilot signal be positioned at the DC position.
4. device according to claim 2, wherein said DC remover is a high pass filter.
5. device according to claim 1, this device further comprises:
Pilot extractor is used in frequency domain the signal that the frame of rotation broadcast singal comprises, and extracts pilot signal from frame thus.
6. device according to claim 5, wherein said pilot extractor comprises:
The 3rd calculator is used for broadcast singal is carried out the frequency rotation; And
The DC extractor is used for extracting direct current DC composition from the postrotational signal of frequency.
7. device according to claim 6, wherein:
The frame of broadcast singal comprises the double pilot signal, and
Described the 3rd calculator carries out the frequency rotation to this double pilot signal, makes this double pilot signal be positioned at the DC position.
8. device according to claim 6, wherein said DC extractor is a low pass filter.
9. method that is used for receiving broadcast signal, this method comprises:
First step, the broadcast singal that receiving broadcast signal and output receive;
Second step is carried out demodulation to the broadcast singal that receives;
Third step carries out equilibrium to the broadcast singal after the demodulation;
The 4th step is proofreaied and correct the error of transmission of the broadcast singal after the equilibrium; And
The 5th step, the output signal of the above-mentioned arbitrary steps of rotation in frequency domain, and remove the pilot signal that comprises in the frame of the postrotational signal of frequency.
10. method according to claim 9, wherein said the 5th step comprises:
The output signal of any one in first, second and the third step of rotation in frequency domain;
From the postrotational signal of frequency, remove direct current DC composition; And
Signal behind the removal DC is carried out the frequency rotation, make that the signal behind the removal DC returns to residing home position in the frequency domain.
11. method according to claim 10, wherein said in frequency domain the step of rotating signal comprise:
Make that the output signal of any one comprises the double pilot signal in first, second and the third step; And
This double pilot signal frequency is rotated to the DC position.
12. method according to claim 10, the step of wherein said removal DC composition comprises:
Make the postrotational signal of frequency by high pass filter, thereby from the postrotational signal of frequency, remove the DC composition.
13. method according to claim 9, this method further comprises:
The signal that in frequency domain, comprises in the rotation frame, and from frame, extract pilot signal.
14. method according to claim 13, the step of wherein said extraction pilot signal comprises:
The signal that comprises in the frame is carried out the frequency rotation; And
From the postrotational signal of frequency, extract direct current DC composition.
15. method according to claim 14, wherein:
Postrotational signal, extract in the step of DC composition, extract the DC composition of the postrotational signal of frequency by low pass filter from frequency.
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CN101867446A (en) * 2009-04-15 2010-10-20 Lg电子株式会社 Transmit the method for receiving broadcast signal and transmit receiving broadcast signal equipment
CN101447837B (en) * 2008-12-26 2012-06-06 华为技术有限公司 Single-carrier signal detection method and device
CN109905524A (en) * 2017-12-11 2019-06-18 中国移动通信集团湖北有限公司 Telephone number recognition methods, device, computer equipment and computer storage medium

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JPH0624342B2 (en) * 1988-06-29 1994-03-30 日本電気株式会社 Uplink cross polarization compensator
WO2003001760A1 (en) 2001-06-22 2003-01-03 Thomson Licensing S.A. Method and system for compensation of a carrier frequency offset in an ofdm receiver
ATE459215T1 (en) 2002-11-19 2010-03-15 Nxp Bv RECIPIENT
KR100751098B1 (en) * 2006-02-16 2007-08-22 주식회사 팬택앤큐리텔 Method and apparatus of transmitting pilot symbols in orthogonal frequency division multiplexing based communication system, method and apparatus of receiving the pilot symbols

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CN101447837B (en) * 2008-12-26 2012-06-06 华为技术有限公司 Single-carrier signal detection method and device
CN101867446A (en) * 2009-04-15 2010-10-20 Lg电子株式会社 Transmit the method for receiving broadcast signal and transmit receiving broadcast signal equipment
CN101867446B (en) * 2009-04-15 2016-08-03 Lg电子株式会社 Transmit and receive the method for broadcast singal and transmit reception broadcast singal equipment
CN109905524A (en) * 2017-12-11 2019-06-18 中国移动通信集团湖北有限公司 Telephone number recognition methods, device, computer equipment and computer storage medium
CN109905524B (en) * 2017-12-11 2020-11-20 中国移动通信集团湖北有限公司 Telephone number identification method and device, computer equipment and computer storage medium

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