WO2008062622A1 - Dispositif d'égalisation de forme d'onde - Google Patents
Dispositif d'égalisation de forme d'onde Download PDFInfo
- Publication number
- WO2008062622A1 WO2008062622A1 PCT/JP2007/070457 JP2007070457W WO2008062622A1 WO 2008062622 A1 WO2008062622 A1 WO 2008062622A1 JP 2007070457 W JP2007070457 W JP 2007070457W WO 2008062622 A1 WO2008062622 A1 WO 2008062622A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- waveform equalizer
- tap
- filter
- tap coefficients
- step size
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/04—Control of transmission; Equalising
- H04B3/14—Control of transmission; Equalising characterised by the equalising network used
- H04B3/142—Control of transmission; Equalising characterised by the equalising network used using echo-equalisers, e.g. transversal
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/14—Picture signal circuitry for video frequency region
- H04N5/21—Circuitry for suppressing or minimising disturbance, e.g. moiré or halo
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/005—Control of transmission; Equalising
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L25/03012—Arrangements for removing intersymbol interference operating in the time domain
- H04L25/03019—Arrangements for removing intersymbol interference operating in the time domain adaptive, i.e. capable of adjustment during data reception
- H04L25/03038—Arrangements for removing intersymbol interference operating in the time domain adaptive, i.e. capable of adjustment during data reception with a non-recursive structure
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L25/03012—Arrangements for removing intersymbol interference operating in the time domain
- H04L25/03019—Arrangements for removing intersymbol interference operating in the time domain adaptive, i.e. capable of adjustment during data reception
- H04L25/03057—Arrangements for removing intersymbol interference operating in the time domain adaptive, i.e. capable of adjustment during data reception with a recursive structure
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/02—Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation
- H04L27/06—Demodulator circuits; Receiver circuits
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/0335—Arrangements for removing intersymbol interference characterised by the type of transmission
- H04L2025/03375—Passband transmission
- H04L2025/03382—Single of vestigal sideband
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/03433—Arrangements for removing intersymbol interference characterised by equaliser structure
- H04L2025/03439—Fixed structures
- H04L2025/03445—Time domain
- H04L2025/03471—Tapped delay lines
- H04L2025/03484—Tapped delay lines time-recursive
- H04L2025/03503—Tapped delay lines time-recursive as a combination of feedback and prediction filters
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/03592—Adaptation methods
- H04L2025/03598—Algorithms
- H04L2025/03681—Control of adaptation
- H04L2025/03687—Control of adaptation of step size
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/03592—Adaptation methods
- H04L2025/03598—Algorithms
- H04L2025/03681—Control of adaptation
- H04L2025/037—Detection of convergence state
Definitions
- the present invention relates to a waveform equalizer that removes multipath interference in a receiver for digital broadcasting or digital wireless communication.
- a receiver for digital broadcasting and digital wireless communication is equipped with a waveform equalizer for removing multipath interference.
- Multipath interference means that multiple transmitted waves with different paths arrive at the receiver, and the original received! / Interference wave (ghost) that interferes with the main wave is observed.
- the waveform equalizer restores the main wave that has received such interference.
- the previous ghost is a transmitted wave that reaches the receiver earlier in time than the main wave.
- the post-ghost is a transmission wave that reaches the receiver later in time than the main wave.
- a waveform equalizer is used to compare the FIR (finite impulse response) and IIR (infinite impulse response).
- FIR finite impulse response
- IIR infinite impulse response
- Patent Document 1 JP 2005-39687 A
- the FIR tap coefficient may misconverge depending on the ghost included in the input signal.
- the tap coefficient of the FIR filter misconverges due to the influence of the ghost after suppression by the IIR filter, which deteriorates the waveform equalization performance.
- a waveform equalization apparatus is a waveform equalization apparatus that performs waveform equalization on an input signal and outputs the result as an output signal, between the input signal and a plurality of tap coefficients.
- a FIR (finite impulse response) filter that performs a convolution operation at, an IIR (infinite impulse response) filter that performs a convolution operation between the output signal and a plurality of tap coefficients, an operation result of the FIR filter, and the IIR filter
- An addition unit that adds the calculation result and outputs the result as the output signal, an error detection unit that detects and outputs an error of the output signal, and tap coefficients of the FIR filter and the IIR filter
- a tap coefficient updating unit for updating based on.
- the tap coefficient updating unit updates the tap coefficient of the IIR filter with a step size for updating the tap coefficient of the FIR filter from when the operation of the waveform equalizer starts until a predetermined condition is satisfied. Make it smaller than the step size required.
- the step size for updating the tap coefficient of the FIR filter is set to update the tap coefficient of the IIR filter until the predetermined condition is satisfied from the start of the operation of the waveform equalizer. Since it is smaller than the step size, the tap coefficient of the IIR filter can converge faster than the tap coefficient of the FIR filter. Therefore, it is possible to prevent the tap coefficients of the FIR filter from converging incorrectly due to the ghost effect suppressed by the IIR filter.
- the step size is appropriately controlled when updating the tap coefficients of the FIR filter and the IIR filter, it is possible to prevent the tap coefficients of the FIR filter from converging to an incorrect value. it can. Since a relatively simple circuit is used, the waveform equalization performance of the waveform equalization apparatus can be improved without significantly increasing the circuit area.
- FIG. 1 is a block diagram showing a configuration of a waveform equalizing apparatus according to an embodiment of the present invention.
- FIG. 2 is a block diagram illustrating a configuration example of the FIR filter of FIG.
- FIG. 3 is a block diagram showing a configuration example of the IIR filter of FIG.
- FIG. 4 is a block diagram showing a configuration example of a tap coefficient updating unit in FIG.
- FIG. 5 is a block diagram showing a configuration example of a step size control unit in FIG.
- FIG. 6 is a block diagram showing a configuration of a modification of the step size control unit in FIG.
- FIG. 7 is a block diagram showing a configuration of another modification of the step size control unit in FIG.
- FIG. 1 is a block diagram showing a configuration of a waveform equalizer according to an embodiment of the present invention.
- the waveform equalization apparatus 1 includes an FIR filter 10, an IIR filter 20, an adder 32, an error detection unit 34, and a tap coefficient update unit 40.
- This waveform equalizer is used, for example, in an ATSC (Advanced 1 elevision Systems Committee) VSB ⁇ vestigial-sideband receiver.
- the waveform equalization apparatus in FIG. 1 receives an input signal IS including a main wave and an interference wave (ghost). This waveform equalizer restores the main wave from the input signal IS and outputs the obtained result as the output signal ES.
- the FIR filter 10 delays the input signal IS and obtains a plurality of tap values that have received different delays by a predetermined time.
- the FIR filter 10 performs a convolution operation between the input signal IS and a plurality of tap coefficients respectively corresponding to these tap values using the plurality of tap values, and the result is used as an adder 32 as a signal FO. Output to.
- the IIR filters 20 delay the output signal ES of the waveform equalizer in FIG. A plurality of tap values having different delays for each time are obtained.
- the IIR filter 20 performs a convolution operation between the output signal ES and a plurality of tap coefficients respectively corresponding to these tap values using the plurality of tap values, and the result is used as an adder 3 as a signal IO. Output to 2.
- the adder 32 adds the signal FO and the signal IO, and outputs the result as an output signal ES.
- the error detector 34 detects an error ER between the output signal ES and a desired signal and outputs the error ER to the tap coefficient update unit 40.
- the tap coefficient updating unit 40 updates the tap coefficients of the FIR filter 10 and the IIR filter 20 according to the error ER.
- Delay devices 12B to 12N the outputs of 12N are tap values FTP2, FTP 3,..., FTPn, respectively.
- Tap values FTP;! To FTPn correspond to tap coefficients FC1, FC2, ..., FCn, respectively.
- the delay T is equal to the symbol period of the input signal IS.
- FIG. 3 is a block diagram illustrating a configuration example of the IIR filter 20 of FIG.
- the IIR filter 20 includes m ⁇ l delay units 22B, 22C,..., 221,..., 22M and m multipliers 24 A, 24B,. ..., 24M and Calorie calculator 26.
- IIR Finale 20 also taps
- the configuration is almost the same as the FIR filter 10 in FIG. 1 except that the number and tap coefficients are different.
- the outputs of the delay devices 22B to 22M are tap values ITP2, ITP3, ..., ITPm, respectively.
- Tap values ITP;! To ITPm are associated with tap coefficients IC1, IC1,..., ICm, respectively.
- tap coefficients FC;! To FCn are set to FC
- tap values FTP;! To FTPn are set to FTP
- tap coefficients IC;! To ICm are set to IC
- tap values ITP;! To ITPm are set.
- FIG. 4 is a block diagram illustrating a configuration example of the tap coefficient updating unit 40 in FIG.
- the tap coefficient updating unit 40 includes multipliers 51, 52, 53, 54, integrators 55, 56, and a step size control unit 58.
- multipliers 51, 52, 53, 54, integrators 55, 56, and a step size control unit 58 are multipliers 51, 52, 53, 54, integrators 55, 56, and a step size control unit 58.
- LMS Least Mean Square
- the step size control unit 58 outputs the FIR step size SSF for updating the filter coefficient of the FIR filter 10 and the IIR step size SSI for updating the filter coefficient of the IIR filter 20.
- FIG. 5 is a block diagram illustrating a configuration example of the step size control unit 58 of FIG.
- the step size control unit 58 in FIG. 5 has a comparator 62 and a counter 64.
- the tap coefficient of the IIR filter 20 is made larger than the tap coefficient of the FIR filter 10. It can be converged quickly. Therefore, it is possible to prevent the tap coefficients of the FIR filter 10 from misconvergence due to the ghost effect suppressed by the IIR filter 20. As a result, the waveform equalization performance of the waveform equalizer can be improved.
- FIG. 6 is a block diagram showing a configuration of a modification of the step size control unit 58 of FIG.
- the step size control unit 258 in FIG. 6 has a comparator 262 and a differentiator 66.
- the differentiator 66 receives the tap coefficients IC ;! to ICm from the IIR filter 20, obtains the absolute values of the differential values for each of these tap coefficients, and further calculates the sum ADI of these absolute values. And output to the comparator 262.
- the comparator 262 compares the total ADI with the switching threshold value, and outputs the FIR step size SSF according to the result.
- Comparator 262 outputs 1/32 as FIR step size SSF and 1/8 as IIR step size SSI when total ADI is 0.05 or more. In addition, the comparator 262 If is smaller than 0.05, 1/8 is output as FIR step size SSF and IIR step size SSI.
- the tap coefficient of the IIR filter 20 converges faster than the tap coefficient of the FIR filter 10.
- the tap coefficient of the FIR filter 10 can be prevented from erroneously converging due to the influence of the ghost suppressed by the IIR filter 20.
- the convergence time of the tap coefficient of the FIR filter 10 can be shortened.
- FIG. 7 is a block diagram showing a configuration of another modification of the step size control unit 58 of FIG.
- the step size control unit 358 in FIG. 7 includes a comparator 362, a counter 64, and a differentiator 66.
- the counter 64 and the differentiator 66 are the same as those described with reference to FIGS. 5 and 6, respectively. That is, the counter 64 starts a count operation at the start of the operation of the waveform equalizer in FIG. 1, and measures an elapsed time from the start of the operation of the waveform equalizer.
- the differentiator 66 receives the tap coefficients IC;! To ICm from the II R filter 20, obtains the absolute value of the differential value for each of these tap coefficients, and further obtains the sum ADI of these absolute values to obtain the comparator 36. Output to 2.
- Comparator 362 increases the switching threshold when total ADI is equal to or greater than a predetermined value, and decreases the switching threshold when total ADI is smaller than the predetermined value.
- the other points are the same as the comparator 62.
- the tap coefficient of the IIR filter 20 converges faster than the tap coefficient of the FIR filter 10. It is possible to prevent the tap coefficients of the FIR filter 10 from misconvergence.
- FIR step size SSF IIR step size SSI, and each switching threshold shown in the above embodiment are merely examples, and may be other values.
- the FIR step size SSF may be 0! / ⁇ .
- the present invention can prevent the tap coefficient of the FIR filter from converging to an incorrect value, and thus is useful for a waveform equalizer and the like.
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/304,041 US8165192B2 (en) | 2006-11-22 | 2007-10-19 | Waveform equalizer |
JP2008545336A JP4994389B2 (ja) | 2006-11-22 | 2007-10-19 | 波形等化装置 |
EP07830191A EP2043280A1 (en) | 2006-11-22 | 2007-10-19 | Waveform equalizing device |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2006315690 | 2006-11-22 | ||
JP2006-315690 | 2006-11-22 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2008062622A1 true WO2008062622A1 (fr) | 2008-05-29 |
Family
ID=39429561
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2007/070457 WO2008062622A1 (fr) | 2006-11-22 | 2007-10-19 | Dispositif d'égalisation de forme d'onde |
Country Status (6)
Country | Link |
---|---|
US (1) | US8165192B2 (ja) |
EP (1) | EP2043280A1 (ja) |
JP (1) | JP4994389B2 (ja) |
KR (1) | KR20090010038A (ja) |
CN (1) | CN101490972A (ja) |
WO (1) | WO2008062622A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011217162A (ja) * | 2010-03-31 | 2011-10-27 | Fujitsu Ltd | 制御装置及び方法、並びに信号処理装置 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001508959A (ja) * | 1996-11-19 | 2001-07-03 | トムソン マルチメデイア ソシエテ アノニム | スパース適応型等化フィルタ |
JP2001267981A (ja) * | 2000-03-17 | 2001-09-28 | Nec Corp | 等化器 |
JP2005039687A (ja) | 2003-07-18 | 2005-02-10 | Matsushita Electric Ind Co Ltd | 波形等化装置 |
JP2005528854A (ja) * | 2002-06-04 | 2005-09-22 | クゥアルコム・インコーポレイテッド | 判定フィードバックイコライザと線形イコライザとを選択する受信機 |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5901075A (en) * | 1995-12-22 | 1999-05-04 | Lucent Technologies Inc. | Performance of an adaptive weight FIR filter having a timeshared tap weight processor |
JP3216704B2 (ja) * | 1997-08-01 | 2001-10-09 | 日本電気株式会社 | 適応アレイ装置 |
US6426972B1 (en) * | 1998-06-19 | 2002-07-30 | Nxtwave Communications | Reduced complexity equalizer for multi mode signaling |
US6490628B2 (en) * | 1998-09-25 | 2002-12-03 | Intel Corporation | Modem using a digital signal processor and a signal based command set |
US6661848B1 (en) * | 1998-09-25 | 2003-12-09 | Intel Corporation | Integrated audio and modem device |
US6711205B1 (en) * | 1998-09-25 | 2004-03-23 | Intel Corporation | Tone detector for use in a modem |
US6351781B1 (en) * | 1998-09-25 | 2002-02-26 | Intel Corporation | Code swapping techniques for a modem implemented on a digital signal processor |
GB9907354D0 (en) | 1999-03-30 | 1999-05-26 | Univ Bristol | Adaptive filter equalisation techniques |
US7050491B2 (en) * | 2001-10-15 | 2006-05-23 | Mcdonald James Douglas | Adaptive equalization of digital modulating signal recovered from amplitude-modulated signal subject to multipath |
-
2007
- 2007-10-19 KR KR1020087026498A patent/KR20090010038A/ko not_active Application Discontinuation
- 2007-10-19 JP JP2008545336A patent/JP4994389B2/ja not_active Expired - Fee Related
- 2007-10-19 US US12/304,041 patent/US8165192B2/en active Active
- 2007-10-19 EP EP07830191A patent/EP2043280A1/en not_active Withdrawn
- 2007-10-19 CN CNA2007800259902A patent/CN101490972A/zh active Pending
- 2007-10-19 WO PCT/JP2007/070457 patent/WO2008062622A1/ja active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001508959A (ja) * | 1996-11-19 | 2001-07-03 | トムソン マルチメデイア ソシエテ アノニム | スパース適応型等化フィルタ |
JP2001267981A (ja) * | 2000-03-17 | 2001-09-28 | Nec Corp | 等化器 |
JP2005528854A (ja) * | 2002-06-04 | 2005-09-22 | クゥアルコム・インコーポレイテッド | 判定フィードバックイコライザと線形イコライザとを選択する受信機 |
JP2005039687A (ja) | 2003-07-18 | 2005-02-10 | Matsushita Electric Ind Co Ltd | 波形等化装置 |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011217162A (ja) * | 2010-03-31 | 2011-10-27 | Fujitsu Ltd | 制御装置及び方法、並びに信号処理装置 |
Also Published As
Publication number | Publication date |
---|---|
US8165192B2 (en) | 2012-04-24 |
JPWO2008062622A1 (ja) | 2010-03-04 |
US20100013570A1 (en) | 2010-01-21 |
CN101490972A (zh) | 2009-07-22 |
EP2043280A1 (en) | 2009-04-01 |
JP4994389B2 (ja) | 2012-08-08 |
KR20090010038A (ko) | 2009-01-28 |
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