WO2008023539A1 - Récepteur, circuit intégré et procédé de réception - Google Patents
Récepteur, circuit intégré et procédé de réception Download PDFInfo
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- WO2008023539A1 WO2008023539A1 PCT/JP2007/064896 JP2007064896W WO2008023539A1 WO 2008023539 A1 WO2008023539 A1 WO 2008023539A1 JP 2007064896 W JP2007064896 W JP 2007064896W WO 2008023539 A1 WO2008023539 A1 WO 2008023539A1
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- 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
- H04L25/0202—Channel estimation
- H04L25/0222—Estimation of channel variability, e.g. coherence bandwidth, coherence time, fading frequency
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/30—Monitoring; Testing of propagation channels
- H04B17/309—Measuring or estimating channel quality parameters
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0045—Arrangements at the receiver end
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0045—Arrangements at the receiver end
- H04L1/0047—Decoding adapted to other signal detection operation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0045—Arrangements at the receiver end
- H04L1/0054—Maximum-likelihood or sequential decoding, e.g. Viterbi, Fano, ZJ algorithms
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- 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
- H04L25/0202—Channel estimation
- H04L25/0224—Channel estimation using sounding signals
- H04L25/0228—Channel estimation using sounding signals with direct estimation from sounding signals
- H04L25/023—Channel estimation using sounding signals with direct estimation from sounding signals with extension to other symbols
- H04L25/0232—Channel estimation using sounding signals with direct estimation from sounding signals with extension to other symbols by interpolation between sounding signals
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
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- 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
- H04L25/03159—Arrangements for removing intersymbol interference operating in the frequency domain
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2647—Arrangements specific to the receiver only
- H04L27/2655—Synchronisation arrangements
- H04L27/2657—Carrier synchronisation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/003—Arrangements for allocating sub-channels of the transmission path
- H04L5/0048—Allocation of pilot signals, i.e. of signals known to the receiver
Definitions
- Receiving device integrated circuit, and receiving method
- the present invention relates to an equalization technique for compensating for propagation distortion in mobile reception such as terrestrial digital television broadcasting.
- Digital terrestrial television broadcasting systems include, for example, Japanese ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) 1 -European DVB-T (Digital Video Broadcasting-Terrestrial) systems. Is one of the multi-carrier transmission systems, and adopts 3 ⁇ 4> OFDM (Orthogonal Frequency Division Multiplexing) fe;
- OFDM Orthogonal Frequency Division Multiplexing
- the transmitter is BPSK (Binary Phase Shift Keying) modulated with a known amplitude and phase on the receiving side called a distributed pilot signal (hereinafter referred to as SP signal).
- SP signal a distributed pilot signal
- a pilot signal is transmitted periodically.
- the receiving device sequentially estimates the channel characteristics by monitoring the amplitude and phase of the SP signal contained in the received signal, and equalizes the received signal using the estimated channel characteristics.
- the vertical axis represents the time in symbol units, and the horizontal axis represents the frequency in carrier units.
- the black circle is the SP signal, and the white circle is the data modulation signal modulated by the transmission data.
- the SP signal is arranged for every 12 carriers in one symbol, shifted by 3 carriers for each symbol, and arranged and transmitted so as to circulate in 4 symbols.
- FIG. 17 shows a configuration of a conventional receiving apparatus that receives digital terrestrial television broadcasting using the OFDM transmission method.
- a broadcast wave emitted from a broadcasting station is received by the antenna 101 via a transmission path. Then, tuner 102 selects a desired broadcast wave from a plurality of broadcast waves received by antenna 101, and converts the selected broadcast wave into a predetermined frequency band.
- AFC (Automatic Frequency Control) unit 103 receives a signal input from tuner 102.
- the frequency error that occurs when the broadcast wave is selected is removed from the signal, and the received signal from which the frequency error has been removed is output to the subsequent circuit section.
- the configuration of the AFC unit 103 is disclosed in Patent Document 1, for example.
- Symbol synchronization section 104 estimates the symbol timing based on the received signal input from AFC section 103.
- Fourier transform section 105 performs a Fourier transform on the received signal input from AFC section 103 according to the symbol timing estimated by symbol synchronization section 104.
- Equalization section 106 estimates the transmission path characteristics based on the received signal input from Fourier transform section 105, and equalizes the received signal based on the estimated transmission path characteristics.
- FIG. 18 shows a configuration of the equalization unit 106 of FIG.
- the configuration of the equalization unit 106 in FIG. 17 is the configuration disclosed in Patent Document 2.
- the received signal after the Fourier transform by the Fourier transform unit 105 is supplied to each of the SP signal extraction unit 151 and the division unit 153.
- the SP signal extraction unit 151 extracts the SP signal from the received signal and uses the extracted SP signal to estimate the transmission path characteristic at the position where the SP signal is arranged (hereinafter referred to as the SP signal position). Determine.
- the transmission path estimation unit 152 estimates transmission path characteristics at a position where the data modulation signal is arranged (hereinafter referred to as data modulation signal position) based on the transmission path characteristics at the SP signal position.
- the division unit 153 equalizes the data modulation signal by dividing the data modulation signal by the transmission path characteristic estimated by the transmission path estimation unit 152.
- transmission path estimation section 152 performs symbol interpolation filter 152a that performs symbol direction interpolation processing and carrier direction interpolation processing. And a carrier interpolation filter 152b for performing.
- the Doppler frequency estimation unit 154 observes the time variation of the transmission path characteristics estimated by the SP signal extraction unit 151, and estimates the speed of the fluctuation of the transmission path characteristics, that is, the Doppler frequency.
- the interpolation filter selection unit 156 selects a filter coefficient stored in a filter coefficient ROM (Read Only memory) 155 in accordance with the Doppler frequency estimated by the Doppler frequency estimation unit 154.
- the symbol interpolation filter 152 a is a finale selected by the interpolation filter selection unit 152.
- the pass bandwidth of the frequency transfer characteristic of the filter is changed by the data coefficient, and interpolation processing in the symbol direction is performed.
- the symbol interpolation filter 152a can more effectively remove noise included in the transmission path characteristics estimated by the SP signal extraction unit 151 as the pass bandwidth is narrower.
- the lower the moving speed of the receiving apparatus the narrower the frequency bandwidth occupied by fluctuations in transmission path characteristics caused by Doppler fluctuations! /. Therefore, the lower the moving speed of the receiving apparatus, the lower the pass bandwidth of the symbol interpolation filter 152a. Can be narrowed.
- the equalizer 106 effectively removes noise included in the transmission path characteristics by adjusting the pass bandwidth of the frequency transfer characteristics according to the moving speed of the receiving apparatus.
- the channel characteristics estimated by SP signal extraction section 151 can be obtained only at intervals of 4 symbols in the symbol direction. For this reason, if the symbol period is T seconds, the passing bandwidth of the symbol interpolation filter 152a cannot be increased to more than 1 / (4T) Hertz from the complex signal sampling theorem! /.
- Patent Document 1 Japanese Patent No. 3074103
- Patent Document 2 Japanese Patent Publication No. 2005-286636
- Fig. 19 shows that in a surface fuzzing environment where a specular wave (also called a direct wave or a standing wave) and a scattered wave are received simultaneously, the specular wave arrives from the front in the direction of travel, and the specular wave shifts to the Doppler frequency. This is the case. It is assumed that scattered waves are coming uniformly from all directions.
- a specular wave also called a direct wave or a standing wave
- the vertical axis represents the spectral density (dB), and in FIG. 19 (d), the vertical axis represents the gain (dB).
- Fig. 19 (a) shows the temporal variation of the transmission path characteristics in the rice fading environment when the specular wave arrives from the front in the traveling direction, expressed as the equivalent low-band spectral density.
- S represents the specular wave component
- D in the ellipse
- Scattered wave component D is distributed up to + f, where f is the maximum Doppler frequency.
- the specular wave component S coming from the front in the direction is frequency shifted to + f.
- FIG. 19 (b) shows the time variation of the transmission path characteristics observed in the received signal output from the AFC unit 103 in terms of spectral density.
- the AFC unit 103 regards the Doppler frequency shift of the specular wave component S as the frequency error of the received signal and removes the frequency error of the received signal. Take control.
- the spectral density of the transmission path characteristics observed in the received signal output from the AFC unit 103 is frequency-shifted so that the specular wave component S is in the vicinity of direct current (frequency is 0).
- the A FC unit 103 virtually shifts the frequency of the transmission path characteristics related to the received signal.
- FIG. 19 (c) shows the time variation of the transmission path characteristics observed by the SP signal included in the received signal when the output of the AFC unit 103 is input to the equalizing unit 106 via the Fourier transform unit 105. It is expressed in petal density.
- FIG. 19D shows the frequency transfer characteristic of the symbol interpolation filter 152a.
- the symbol interpolation filter 152a applies power to the received signal output by the AFC unit 103 shown in FIG. 19 (b) by filtering the transmission path characteristics observed at the SP signal position shown in FIG. 19 (c). Estimate transmission path characteristics.
- Fig. 19 (e) shows the component of the desired channel characteristics among the channel characteristics observed at the SP signal position shown in Fig. 19 (c) (reception output from the AFC unit 103 shown in Fig. 19 (b)).
- the transmission path characteristics obtained by filtering the transmission path characteristics of the signal with the symbol interpolation filter 152a are represented by spectral density.
- FIG. 19 (f) shows a component blocked by filtering a desired channel characteristic component among the channel characteristics observed at the SP signal position shown in FIG. 19 (c) by the symbol interpolation filter 152a. Is represented by spectral density.
- the transmission path characteristics output from the symbol interpolation filter 152a are It can be seen that the desired transmission line characteristic power is a transmission line characteristic lacking low frequency components.
- Fig. 19 (g) shows the component of the channel characteristic due to aliasing among the channel characteristics observed at the SP signal position shown in Fig. 19 (c) (the SP signal shown in Fig. 19 (c)).
- the channel characteristics obtained by filtering the channel characteristics component (excluding the desired channel characteristics shown in Fig. 19 (b) from the observed channel characteristics) with the symbol interpolation filter 152a are expressed in terms of spectral density. It is a representation.
- FIG. 19 (f) and FIG. 19 (g) are errors in interpolation by the symbol interpolation filter 152a, causing errors in the estimation of the transmission path characteristics in the transmission path estimation unit 152, and in the equalization unit 106. This causes a demodulation error.
- the power fading wave described in the example of the rice fading environment is a multipath propagation environment including a specular wave, and the SFN (Single Frequency Network) environment utilizing the multipath tolerance of the OFDM transmission method.
- the automatic frequency control unit 103 has a relatively high power arrival.
- the same problem as in the rice fading environment occurs when frequency control is performed by regarding the wave Doppler frequency shift as the frequency error of the received signal.
- an object of the present invention is to provide a receiving device, an integrated circuit, and a receiving method that improve the reception quality by more accurately estimating the time variation of the transmission path characteristics.
- the receiving apparatus of the present invention includes a transmission path characteristic calculating unit that calculates a transmission path characteristic for a pilot signal based on a pilot signal included in the received signal, and the transmission path characteristic calculation.
- the transmission line characteristics calculated by the filter unit are subjected to at least one of interpolation and band limitation by filtering, and the frequency transfer characteristic of the filter process can be shifted in frequency, and the transmission processed by the filter unit Based on road characteristics
- An equalization unit that equalizes the received signal, and a filter control unit that determines a shift amount for frequency shifting the frequency transfer characteristic of the filter unit and controls the frequency transfer characteristic of the filter unit.
- the filter control unit observes a transmission path characteristic for the first signal included in the received signal, determines a shift amount of the frequency transfer characteristic of the filter unit based on an observation result, and The filter unit shifts the frequency transfer characteristic of the filter processing based on the shift amount determined by the filter control unit.
- the integrated circuit of the present invention includes a transmission line characteristic calculation unit that calculates transmission line characteristics for the pilot signal based on a pilot signal included in the received signal, and a transmission line calculated by the transmission line characteristic calculation unit.
- the filter processing is performed at least one of interpolation and band limitation by filtering! /, The frequency transfer characteristics of the filter processing can be shifted in frequency, and the transmission path characteristics processed by the filter section. ! /,
- An equalization unit that equalizes the received signal, and a filter control unit that determines a shift amount for frequency shifting the frequency transfer characteristic of the filter unit and controls the frequency transfer characteristic of the filter unit.
- the filter control unit observes a transmission path characteristic with respect to the first signal included in the received signal, and based on the observation result! /, The amount of shift of the frequency transfer characteristic of the filter unit Determined, the filter unit, the frequency shift the frequency transfer characteristics of the filter based on the shift amount determined by the filter control unit.
- the reception method of the present invention is capable of frequency-shifting the transmission line characteristic calculation procedure for calculating the transmission line characteristic for the pilot signal based on the pilot signal included in the reception signal and the frequency transfer characteristic of the filter processing.
- a filter procedure for performing at least one of interpolation and band limitation on the transmission line characteristic calculated in the transmission line characteristic calculation procedure by a filter unit by filtering, and on the transmission line characteristic processed by the filter procedure An equalization procedure for equalizing the received signal, and a filter control procedure for determining a shift amount for frequency shifting the frequency transfer characteristic of the filter unit and controlling the frequency transfer characteristic of the filter unit, and
- the filter control procedure observes the transmission path characteristics for the first signal included in the received signal, and based on the observation result!
- the shift amount of the frequency transfer characteristic of the filter unit is determined, and the filter unit shifts the frequency transfer characteristic of the filter processing based on the shift amount determined by the filter control procedure.
- the frequency transfer characteristic is f (f)
- the frequency shift of the frequency transfer characteristic f (f) is ⁇ f
- the frequency transfer characteristic f (f) is the shift amount ⁇ f and the frequency transfer after the frequency shift.
- the characteristic is g (f)
- the relationship f (f) g (f + ⁇ f) is satisfied.
- the filter control unit observes the transmission path characteristic for the first signal, and based on the observation result, determines the frequency transfer characteristic of the filter unit. Shift the frequency. As a result, the ratio of the desired transmission path characteristic component of the transmission path characteristics calculated by the transmission path characteristic calculation section to the filter section is increased, and other than the desired transmission path characteristic component. It becomes possible to reduce the rate at which the component passes through the filter section, and it is possible to more accurately estimate the time variation of the transmission path characteristics.
- the pilot signal is inserted into the received signal for each M (M is an integer of 2 or more) symbols and transmitted, and the first signal is N (N is less than M and is 1 or more).
- An integer) symbol is inserted and transmitted, and the filter control unit calculates a transmission line characteristic for the first signal based on the first signal, and the first transmission line
- the first filter unit that performs the filtering process on the transmission path characteristic calculated by the characteristic calculating unit while sequentially shifting the frequency transfer characteristic of the filter process and the output signal of the first filter unit are observed, and based on the observation result
- a shift amount determining unit that determines the shift amount of the frequency transfer characteristic of the filter unit may be provided.
- the shift amount determination unit calculates a power value of an output signal of the first filter unit, and outputs a calculation result as an output signal; and the power value calculation unit And detecting the maximum value of the output signal, and based on the shift amount of the frequency transfer characteristic of the first filter unit when the output signal of the power value calculation unit reaches the maximum value, the filter unit A maximum value detecting unit that determines a shift amount of the frequency transfer characteristic.
- the shift amount determination unit includes a difference between an output signal of the first transmission path characteristic calculation unit and a signal obtained by filtering the output signal by the first filter unit. And a difference calculation unit that outputs a difference result as an output signal, and the difference The power value of the output signal of the minute calculation unit is calculated, and the power value calculation unit that outputs the calculation result as an output signal, and the output signal of the power value calculation unit is observed to detect the minimum value of the output signal, and the A minimum value detection unit that determines a shift amount of the frequency transfer characteristic of the filter unit based on a shift amount of the frequency transfer characteristic of the first filter unit when the output signal of the power value calculation unit becomes a minimum value; You may make it prepare.
- the frequency transfer characteristic of the filter unit is obtained by using the transmission line characteristic in which the aliasing component appears at an interval larger than the interval in which the aliasing component related to the transmission line characteristic calculated by the transmission line characteristic calculation unit appears.
- the shift amount for frequency shift is determined. Therefore, it is possible to determine the shift amount for frequency shifting the frequency transfer characteristics of the filter unit without including an aliasing component, and it is possible to determine the shift amount more appropriately.
- the first signal may be inserted every symbol.
- the first signal may be a continuous pilot signal in the DVB-T system.
- the first signal may be a TMCC signal in the ISDB-T system or a TPS signal in the DVB-T system.
- the transmission path characteristic calculation unit includes a decoding unit that decodes the TMCC signal or the TPS signal, and a retransmission unit that performs DBPSK modulation on the control information transmitted by the T MCC signal or the TPS signal based on a decoding result by the decoding unit.
- the TMCC signal or TPS signal inserted into the received signal and transmitted, and the TMCC signal or TPS signal obtained by DBPSK modulation by the re-modulation unit, the TMCC signal or the TPS signal And a calculation unit for calculating transmission path characteristics for the TPS signal.
- the filter unit can change a pass bandwidth of the frequency transfer characteristic, and the filter control unit observes a transmission line characteristic with respect to the first signal. Based on the pass bandwidth determined by the filter control unit, the filter unit determines the pass bandwidth of the frequency transfer characteristic of the filter unit based on the pass bandwidth determined by the filter control unit. The bandwidth may be changed.
- the desired transmission line characteristic is maintained while maintaining a high ratio of the component of the desired transmission line characteristic of the transmission line characteristic calculated by the transmission line characteristic calculation unit passing through the filter unit. It is possible to more appropriately control the pass band width of the filter unit in which the ratio of components other than the above component to pass through the filter unit is further lowered.
- the receiving apparatus of the present invention is based on an automatic frequency control unit that shifts the frequency of the received signal in order to remove a frequency error that occurs in the received signal, and a pilot signal included in the received signal that has been frequency shifted by the automatic frequency control unit.
- a transmission line characteristic calculation unit for calculating the transmission line characteristic for the pilot signal, and a filter for performing at least one of interpolation and band limitation by filtering the transmission line characteristic calculated by the transmission line characteristic calculation unit Based on the transmission path characteristics processed by the filter unit, and an equalizer unit for equalizing the received signal, and the shift amount by which the automatic frequency control unit shifts the frequency of the received signal is determined.
- a control unit that controls a frequency shift of the received signal of the automatic frequency control unit, wherein the control unit is a transmission path for the first signal included in the received signal.
- the automatic frequency control unit determines the shift amount of the received signal of the automatic frequency control unit based on the observation result, and the automatic frequency control unit determines the shift amount based on the shift amount determined by the control unit.
- the received signal is frequency shifted.
- the integrated circuit of the present invention includes an automatic frequency control unit that shifts the frequency of the received signal in order to remove a frequency error generated in the received signal, and a pilot included in the received signal that is frequency-shifted by the automatic frequency control unit.
- a transmission line characteristic calculation unit for calculating a transmission line characteristic for the pilot signal based on the signal, and at least one of interpolation and band limitation by filtering the transmission line characteristic calculated by the transmission line characteristic calculation unit. Based on the transmission path characteristics processed by the filter unit!
- An equalization unit that equalizes the signal, and a control unit that determines a shift amount by which the automatic frequency control unit shifts the frequency of the received signal and controls the frequency shift of the received signal of the automatic frequency control unit,
- the control unit observes transmission path characteristics with respect to the first signal included in the received signal, determines a shift amount of the received signal of the automatic frequency control unit based on the observation result, and determines the automatic frequency.
- the control unit frequency shifts the reception signal based on the shift amount determined by the control unit.
- the reception method of the present invention includes an automatic frequency control procedure in which the automatic frequency control unit shifts the frequency of the received signal in order to remove a frequency error generated in the received signal, and the frequency shift is performed in the automatic frequency control procedure.
- the transmission path characteristic calculation procedure for calculating the transmission path characteristic for the pilot signal, and the transmission path characteristic calculated by the transmission path characteristic calculation unit are interpolated and banded by filtering.
- a filter procedure for performing at least one of the restrictions processing; an equalization procedure for equalizing the received signal based on transmission path characteristics processed in the filter procedure; and the automatic frequency control unit A control procedure for determining a shift amount to be frequency shifted and controlling a frequency shift of a reception signal of the automatic frequency control unit.
- the transmission path characteristic for the first signal included in the received signal is observed, the shift amount of the received signal of the automatic frequency control unit is determined based on the observation result, and the automatic frequency control unit performs the control procedure. ! /, Based on the shift amount determined by! /, Frequency shift the received signal
- the transmission path characteristic with respect to the first signal is observed, and the automatic frequency control unit shifts the received signal based on the observation result.
- the shift amount is controlled.
- the ratio of the component of the desired transmission path characteristic among the transmission path characteristics calculated based on the pilot signal is increased, and the component other than the component of the desired transmission path characteristic is increased.
- FIG. 1 is a configuration diagram of a receiving device according to a first embodiment.
- FIG. 2 is a configuration diagram of the AFC unit in FIG.
- FIG. 3 is a schematic diagram showing a signal arrangement of distributed pilot signals and continuous pilot signals in the DVB-T system.
- FIG. 4 is a configuration diagram of the configuration of the equalization unit in FIG.
- FIG. 5 is a configuration diagram of the symbol interpolation filter of FIG.
- FIG. 6 is a configuration diagram of the filter control unit in FIG.
- FIG. 7 is a diagram for explaining the operation of the filter control unit of FIG.
- FIG. 8 is a diagram for explaining the operation of the receiving apparatus according to the first embodiment.
- FIG. 9 is a configuration diagram of a filter control unit according to the second embodiment.
- FIG. 10 is a diagram for explaining the operation of the filter control unit in FIG. 9.
- FIG. 11 Schematic diagram showing the signal arrangement of distributed pilot signals and TMCC signals in ISDB-T system.
- FIG. 12 is a configuration diagram of a filter control unit of a third embodiment.
- FIG. 13 is a configuration diagram of a filter control unit according to a fourth embodiment.
- FIG. 14 is a configuration diagram of a receiving device according to a fifth embodiment.
- FIG. 15 is a diagram for explaining the advantages of controlling the frequency shift and pass bandwidth of the frequency transfer characteristic of the symbol interpolation filter.
- FIG. 16 is a schematic diagram showing the signal arrangement of distributed pilot signals in the ISDB-T system and DBV-T system.
- FIG. 17 is a configuration diagram of a conventional receiving apparatus.
- FIG. 18 is a block diagram of the equalization unit in FIG.
- FIG. 19 is a diagram for explaining the operation of a conventional receiving apparatus.
- Minimum value detector 61 TMCC signal extractor
- FIG. 1 is a configuration diagram of a receiving device 1 according to the present embodiment, which is a configuration example of a receiving device that receives terrestrial digital television broadcasting using the OFDM transmission method.
- the receiving apparatus 1 includes an antenna 2, a tuner 3, an AFC unit 4, a symbol synchronization unit 5, a Fourier transform unit 6, an equalization unit 7, an error correction unit 8, and a video / audio decoding unit. 9, a display unit 10, and a speech power 11.
- the antenna 2 receives a broadcast wave emitted from a broadcast station (not shown) via the transmission path, and outputs the received broadcast wave to the tuner 3.
- the tuner 3 selects a desired broadcast wave from a plurality of broadcast waves received by the antenna 2, converts the selected broadcast wave to a predetermined frequency band, and converts the selected broadcast wave into a predetermined frequency band obtained by the conversion. Outputs frequency band received signal to AFC section 4.
- the AFC unit 4 removes the frequency error generated when the broadcast wave is selected from the received signal input from the tuner 3, and outputs the received signal from which the frequency error has been removed to the symbol synchronization unit 5 and the Fourier transform unit 6, respectively. . Details of the AFC unit 4 will be described later with reference to FIG.
- the symbol synchronization unit 5 estimates symbol timing based on the received signal input from the AFC unit 4 and notifies the estimated symbol timing to the Fourier transform unit 6.
- the Fourier transform unit 6 converts the received signal input from the AFC unit 4 into a received signal in the frequency domain by performing Fourier transform on the received signal input from the AFC unit 4 according to the symbol timing notified by the symbol synchronizing unit 5. .
- the Fourier transform unit 6 then outputs the received signal in the frequency domain obtained by the Fourier transform to the equalization unit 7.
- the equalization unit 7 performs transmission based on the received signal in the frequency domain input from the Fourier transform unit 6.
- the transmission path characteristic is estimated, and the received signal is equalized and demodulated based on the estimated transmission path characteristic. Then, the equalization unit 7 outputs the demodulated reception signal to the error correction unit 8. Details of the equalization unit 7 will be described later with reference to FIG.
- the error correction unit 8 performs error correction processing on the demodulated reception signal input from the equalization unit 7 and outputs the reception signal subjected to error correction processing to the video / audio decoding unit 9.
- the video / audio decoding unit 9 performs a decoding process on the received signal subjected to the error correction process input from the error correction unit 8, and displays the decoded data obtained by the decoding process as video data. 10 or output to the speaker 11 as audio data.
- the display unit 10 performs video display based on the decoded data input from the video / audio decoding unit 9, and the speaker 11 performs audio output based on the decoded data input from the video / audio decoding unit 9.
- FIG. 2 is a block diagram of the AFC unit 4 in FIG.
- the AFC unit 4 includes a frequency oscillation unit 15, a multiplication unit 16, a delay unit 17, a correlation unit 18, and a frequency error detection unit 19.
- the frequency oscillating unit 15 oscillates a complex sine wave whose oscillation frequency is controlled by the frequency error detecting unit 19, and outputs the oscillated complex sine wave to the multiplying unit 16.
- the multiplier 16 multiplies the received signal input from the tuner 3 by the complex sine wave input from the frequency oscillating unit 15, and uses the received signal obtained by the multiplication in each of the symbol synchronization unit 5 and the Fourier transform unit 6. And output to each of the delay unit 17 and the correlation unit 18
- Delay section 17 delays the reception signal input from multiplication section 16 by a time corresponding to the symbol length of the effective symbol, and outputs the delayed signal to correlation section 18.
- the correlation unit 18 performs a correlation calculation between the reception signal input from the multiplication unit 16 and the reception signal input from the delay unit 17 and outputs the calculation result to the frequency error detection unit 19.
- the reception signal input from the delay unit 17 is a signal obtained by delaying the reception signal input from the multiplication unit 16 by a time corresponding to the symbol length of the effective symbol.
- the correlation unit 18 performs a correlation operation between a part of the effective symbols (a part of the signal transmitted in the guard interval) and the signal transmitted in the guard interval.
- the frequency error detector 19 divides the correlation phase angle input from the correlator 18 by the time corresponding to the symbol length of the effective symbol to obtain the frequency error.
- 19 is a frequency oscillation unit that reduces the frequency error based on the obtained frequency error.
- FIG. Fig. 3 is a schematic diagram showing the signal arrangement of SP and CP signals in the DVB-T system.
- the vertical axis represents the time in symbol units
- the horizontal axis represents the frequency in carrier units.
- the black circle is the SP signal
- the double circle is the CP signal
- the white circle is the data modulation signal modulated by the transmission data.
- the SP signal and the CP signal are transmitted to the transmitting side with a predetermined amplitude and a predetermined phase, respectively.
- This signal is a SK (Binary Phase Shift Keying) modulated signal, and a predetermined amplitude and a predetermined phase are known on the receiving side.
- SK Binary Phase Shift Keying
- the SP signal is arranged for every 12 carriers in one symbol, shifted by 3 carriers for each symbol, and arranged and transmitted so as to circulate in 4 symbols.
- the CP signal is transmitted with each symbol arranged on a predetermined carrier. Since the CP signal is allocated to the carrier where the SP signal is allocated, some CP signals (one CP signal per four symbols) also serve as the SP signal.
- FIG. 4 is a block diagram of the equalization unit 7 in FIG.
- the equalization unit 7 includes an SP signal extraction unit 21, an SP signal generation unit 22, a transmission path characteristic calculation unit 23, a simponorene inter-final finalizer 24, a carrier inter-phase interpolating finalizer 25, and a division unit 26. And the Finoletta Wholesale Department 27.
- the received signal after the Fourier transform by the Fourier transform unit 6 is supplied to each of the division unit 26, the SP signal extraction unit 21, and the filter control unit 27.
- the SP signal extraction unit 21 extracts the SP signal (including the CP signal that also serves as the SP signal) from the Fourier-transformed received signal input from the Fourier transform unit 6, and transmits the extracted SP signal to the transmission path characteristics. Output to calculation unit 23.
- the SP signal generation unit 22 generates a signal having the same amplitude and phase as the SP signal obtained by modulation on the transmission side by using a logic circuit or the like, and outputs the generated signal to the transmission path characteristic calculation unit 23.
- Transmission path characteristic calculation unit 23 divides the SP signal input from SP signal extraction unit 21 by the signal input from SP signal generation unit 22, and outputs the division result to symbol interpolation filter 24. .
- the division result is the transmission path characteristic at the position (SP signal position) where the SP signal extracted by the SP signal extraction unit 21 is arranged.
- the symbol interpolation filter 24 is a filter having a structure in which the frequency transfer characteristic representing the relationship between the frequency and the transfer characteristic can be frequency-shifted, and the amount of shift by which the frequency transfer characteristic is frequency-shifted is controlled by the filter control unit 27.
- the symbol interpolation filter 24 estimates the transmission path characteristic at the position (data modulation signal position) where the data modulation signal of the carrier where the SP signal is arranged. , Interpolation in the symbol direction is performed using the transmission path characteristics at the SP signal position.
- a configuration example of the symbol interpolation filter 24 will be described later with reference to FIG.
- the carrier interpolation filter 25 performs interpolation processing in the carrier direction using the acquired transmission path characteristics for each symbol in order to estimate the transmission path characteristics at the data modulation signal position of carriers other than the carrier on which the SP signal is arranged. .
- the division unit 26 equalizes the data modulation signal by dividing the data modulation signal in the reception signal input from the Fourier transform unit 6 by the transmission path characteristic at the position where the data modulation signal is arranged.
- the demodulated data modulation signal is output to the error correction unit 8.
- the filter control unit 27 extracts the received signal power CP signal after the Fourier transform input from the Fourier transform unit 6 and observes the temporal variation of the transmission path characteristics in the carrier on which the CP signal is arranged. The filter control unit 27 then performs a symbol interpolation filter based on the observation result. A shift amount for frequency shifting the frequency transfer characteristic of the filter 24 is determined, and a frequency control signal for notifying the symbol interpolation filter 24 of the determined shift amount is output to the symbol interpolation filter 24.
- the symbol interpolation filter 24 receives the frequency control signal from the filter control unit 27 and shifts the frequency transfer characteristic based on the shift amount indicated by the frequency control signal. In this way, the filter control unit 27 controls the frequency shift of the frequency transfer characteristic of the symbol interpolation filter 24. Details of the filter control unit 27 will be described later with reference to FIG.
- FIG. 5 is a configuration diagram of the symbol interpolation filter 24 of FIG. 4, and is an example in which the symbol interpolation filter 24 is configured by a (2k + 1) tap FIR (Finite Impulse Response) type filter. K is a positive integer.
- the symbol interpolation filter 24 includes 2k delay units 31... 31 31 31 .. 3 k + l — 1 0 1
- phase rotation part 33 33 ... 33 33 33 ... 33 and calorie calculation part 34 k k + l -1 0 1 k
- the data input to the symbol interpolation filter 24 is delayed by 1 symbol,..., (K 1) symbol, k symbol, (k + l) symbol,.
- Multiplier 32 32 ... 32 32 32 ... 32 are respectively input data.
- Rotating part 33 33 ⁇ ⁇ ⁇ 33 33 33 ⁇ ⁇ ⁇ Output to 33.
- Phase rotator 33 33 33 33 33 33 is input respectively
- a frequency control signal indicating the value of ⁇ is input from the filter control unit 27 to the symbol interpolation filter 24, and the phase rotation unit 33 33 33 33 33 33 33
- ⁇ ⁇ 33 is set to the value of ⁇ indicated by the frequency control signal.
- the addition unit 34 is input from the phase rotation unit 33 33 ⁇ 33 33 33 ⁇ 33
- the symbol interpolation filter 24 described above has a configuration in which a phase rotation unit 33 33 ⁇ 33 33 33 ⁇ 33 is added to a general digital filter.
- the frequency transfer characteristic of the symbol interpolation filter 24 when the value of ⁇ is 0 is determined. However, if the symbol period is leap seconds, the SP signal is arranged once every four symbols in the symbol direction, so the pass bandwidth in the frequency transfer characteristic of the symbol interpolation filter 24 is 1 / (4 ⁇ ) hertz at maximum. Up to. The coefficient, b, so that the pass bandwidth in the frequency transfer characteristic of the symbol interpolation filter 24 is 1 / (4 ⁇ ) hertz or less.
- the shift amount by which the frequency transfer characteristic of the symbol interpolation filter 24 is frequency-shifted is determined by ⁇ and the symbol period. For example, if the frequency control signal input from the filter control unit 27 indicates ⁇ radians, and the symbol period is T seconds,
- phase rotation does not occur in phase rotation unit 33, the output of multiplication unit 32 is directly added.
- the symbol interpolation filter 24 may be configured to input to the arithmetic unit 34.
- FIG. 6 is a block diagram of the filter control unit 27 of FIG. [0066]
- the filter control unit 27 includes a CP signal extraction unit 41, a CP signal generation unit 42, a transmission path characteristic calculation unit 43, a filter setting unit 44, a symbol filter 45, a power value calculation unit 46, a maximum And a value detection unit 47.
- the received signal after the Fourier transform by the Fourier transform unit 6 is supplied to the CP signal extraction unit 41.
- the CP signal extraction unit 41 extracts the received signal force CP signal after Fourier transform input from the Fourier transform unit 6, and outputs the extracted CP signal to the transmission path characteristic calculation unit 43.
- the CP signal generation unit 42 generates a signal having the same amplitude and the same phase as the CP signal obtained by modulation on the transmission side by a logic circuit or the like, and outputs the generated signal to the transmission path characteristic calculation unit 43.
- the transmission path characteristic calculation unit 43 divides the CP signal input from the CP signal extraction unit 41 by the signal input from the CP signal generation unit 42 and outputs the division result to the symbol filter 45.
- the division result is a transmission path characteristic at a position where the CP signal extracted by the CP signal extraction unit 41 is arranged (hereinafter referred to as a CP signal position).
- the filter setting unit 44 outputs filter setting information indicating the value of ⁇ corresponding to the shift amount for frequency shifting the frequency transfer characteristic of the symbol filter 45 to the symbol filter 45 and the maximum value detection unit 47. However, the filter setting unit 44 outputs the filter setting information to the symbol filter 45 and the maximum value detection unit 47 while sequentially changing the value of ⁇ indicated by the filter setting information.
- the symbol filter 45 is a filter capable of realizing the same frequency transfer characteristic as the frequency transfer characteristic of the symbol interpolation filter 24.
- the symbol filter 45 has a structure in which the frequency transfer characteristic can be shifted in frequency. This is set by the S-filter setting unit 44 for shifting the frequency.
- the symbol filter 45 of the present embodiment is a filter having the same structure as the symbol interpolation filter 24.
- the coefficients b, b, "', b, b, b,"', b of the symbol filter 45 are k k + 1-1 0 1 k
- the middle rotation of the simpono refinole 45, 33, 33, 33, 33, 33, 33, ... , 33 is set to the value indicated by the filter setting information input from the filter setting unit 44 k
- the symbol filter 45 filters the transmission line characteristic input from the transmission line characteristic calculation unit 43 and outputs the power value calculation unit 46.
- the transmission line characteristic calculation unit 43 calculates the transmission line characteristic for the CP signal that appears for each symbol
- the symbol filter 45 receives data indicating each symbol and the transmission line characteristic.
- the power value calculation unit 46 calculates the power value of the output signal of the symbol filter 45 (filtering result of the symbol filter 45) and outputs the calculation result to the maximum value detection unit 47.
- Maximum value detection unit 47 observes the output signal of power value calculation unit 46 (the power value calculated by power value calculation unit 46) and detects the maximum value of the output signal. Then, the maximum value detection unit 47 converts the frequency control signal indicating the value of ⁇ indicated by the filter setting information input from the filter setting unit 44 when the output signal of the power value calculation unit 46 is the maximum value to the symbol interpolation filter. 24 output.
- the symbol interpolation filter 24 receives the frequency control signal input from the maximum value detection unit 47 in the filter control unit 27 and sets the value of ⁇ of each phase rotation unit in the symbol interpolation filter 24 to a value indicated by the frequency control signal. Thus, the frequency transfer characteristic is shifted in frequency. Then, the symbol interpolation filter 24 filters the transmission line characteristic input from the transmission line characteristic calculation unit 23 based on the frequency transfer characteristic after the frequency shift and outputs the carrier interpolation filter 25.
- FIG. 7 is a diagram for explaining the operation of the filter control unit 27 of FIG.
- the horizontal axis represents the frequency normalized by the symbol frequency f.
- the vertical axis represents the spectral density (dB)
- the vertical axis represents the gain (dB ).
- Fig. 7 (a) shows the time variation of the transmission path characteristics observed by the CP signal in terms of spectral density, that is, the transmission input from the transmission path characteristics calculation unit 43 to the symbol filter 45. It represents the spectral density of the road characteristics. However, since the CP signal is transmitted every symbol, the aliasing component appears at the symbol frequency f interval, and only the portion corresponding to the symbol frequency f is shown! /, And the aliasing component appears in FIG. 7 (a)! / Cunning Les.
- the power value of the output signal of the symbol filter 45 is obtained by shifting the frequency transfer characteristic whose pass bandwidth is, for example, the maximum 1 / (4 T) hertz allowed based on the sampling theorem of complex signals.
- the maximum value can be detected without including aliasing components.
- the filter setting unit 44 shifts the frequency transfer characteristic of the symbol filter 45 by a frequency shift (hereinafter referred to as the frequency shift amount of the frequency transfer characteristic).
- the symbol filter 45 sets the value of ⁇ of each phase rotation unit in the symbol filter 45 to 2 / f (radian) indicated by the filter setting information. Set and shift frequency transfer characteristics by frequency f.
- the transmission path characteristic whose spectral density is shown in Fig. 7 (a) is filtered by the symbol filter 45 whose frequency transfer characteristic is shown in Fig. 7 (b-1).
- the spectral density of the transmission line characteristics filtered by the symbol filter 45 is as shown in Fig. 7 (c-1).
- the power value calculation unit 46 calculates the power value of the output signal of the symbol filter 45, that is, the power value of the transmission path characteristic whose spectral density is shown in FIG. 7 (c-1), and detects the calculated power value as the maximum value. Output to part 47.
- the maximum value detection unit 47 internally holds the value of ⁇ (2 ⁇ ⁇ / f) indicated by the filter setting information input from the filter setting unit 44 as ⁇ , and
- the power value input from the force value calculator 46 is stored internally as P.
- the filter setting unit 44 sets filter setting information in which the frequency shift amount of the frequency transfer characteristic of the symbol filter 45 is set to f, and 2 / f (radian) is the value of ⁇ . Shin
- the symbol filter 45 follows the filter setting information input from the filter setting unit 44.
- the value of ⁇ of each phase rotation unit in the symbol filter 45 is set to 2 / f (radian) indicated by the filter setting information, and the frequency transfer characteristic is frequency-shifted by the frequency f.
- the transmission path characteristic whose spectral density is shown in Fig. 7 (a) is filtered by the symbol filter 45 whose frequency transfer characteristic is shown in Fig. 7 (b-2).
- the spectral density of the transmission line characteristics filtered by the symbol filter 45 is as shown in Fig. 7 (c-2).
- the power value calculation unit 46 calculates the power value of the output signal of the symbol filter 45, that is, the power value of the transmission path characteristic whose spectral density is shown in Fig. 7 (c-2), and detects the calculated power value as the maximum value. Output to part 47.
- the maximum value detection unit 47 compares the power value input from the power value calculation unit 46 with the internally stored P value.
- the maximum value detection unit 47 inputs from the power value calculation unit 46.
- Maximum value detector 47 is a filter setting
- the power value input from the power value calculation unit 46 is held internally as P.
- the filter setting unit 44 sets filter setting information in which the frequency shift amount of the frequency transfer characteristic of the symbol filter 45 is set to f, and 2 / f (radian) is the value of ⁇ . Shin
- the symbol filter 45 sets the value of ⁇ of each phase rotation unit in the symbol filter 45 to 2 / f (radian) indicated by the filter setting information, Frequency transfer characteristic is shifted by frequency f.
- the transmission path characteristics whose spectral density is shown in Fig. 7 (a) are filtered by the symbol filter 45 whose frequency transfer characteristics are shown in Fig. 7 (b-3).
- the spectral density of the transmission line characteristics filtered by the symbol filter 45 is as shown in Fig. 7 (c-3).
- the power value calculation unit 46 calculates the power value of the output signal of the symbol filter 45, that is, the power value of the transmission path characteristic whose spectral density is shown in FIG. 7 (c-3), and detects the calculated power value as the maximum value. Output to part 47.
- the maximum value detection unit 47 is input from the power value calculation unit 46. Power value and the P value held internally.
- the maximum value detector 47 sets the value of ⁇ to 2
- the maximum value detection unit 47 sets the frequency control max 1 s indicating 2 ⁇ f / f indicated by ⁇ as the value of ⁇ .
- the control signal is output to the symbol interpolation filter 24.
- the symbol interpolation filter 24 sets the value of ⁇ of each phase rotation unit in the symbol interpolation filter 24 to 2 / f indicated by the frequency control signal. Symbol interpolation filter 24 frequency
- F is the three types of force S, and the number of frequency shifts is not limited to the above.
- FIG. 8 is a diagram for explaining the operation of the receiving apparatus 1.
- FIG. 8 shows a case where the specular wave arrives from the front in the traveling direction and the specular wave is accompanied by a Doppler frequency shift in a rice fading environment where the specular wave and the scattered wave are received simultaneously. . It is assumed that the scattered wave is coming uniformly from all directions.
- the vertical axis represents the spectral density (dB), and in FIG. 8 (d), the vertical axis represents the gain (dB).
- Fig. 8 (a) shows the temporal fluctuation of the transmission path characteristics in the rice fading environment when the specular wave arrives from the front in the traveling direction, with the spectral density of the equivalent low band.
- S is the specular wave component
- D in the ellipse
- the scattered wave component D is distributed up to + f, where the maximum Doppler frequency is f. How to proceed
- the specular wave component S coming from the front is shifted in frequency to + f.
- the direction of travel is shifted in frequency to + f.
- the specular wave component coming from behind is frequency shifted to -f.
- FIG. 8 (b) shows the time variation of the transmission path characteristics observed in the received signal output from the AFC unit 4 in terms of spectral density.
- Received power of specular wave component S compared to scattered wave component D
- the AFC unit 4 regards the Doppler frequency shift of the specular wave component S as the frequency error of the received signal, and performs frequency control for removing the frequency error of the received signal.
- the spectral density of the transmission path characteristics observed in the received signal output from the AFC unit 4 is frequency-shifted so that the specular wave component S is close to direct current (frequency is 0).
- the AFC unit 4 virtually shifts the frequency of the transmission path characteristics related to the received signal.
- Fig. 8 (c) shows the spectral density of the time variation of the transmission path characteristics observed by the SP signal included in the received signal input from the AFC unit 4 to the equalizing unit 7 via the Fourier transform unit 6. It is a representation.
- FIG. 8D shows the frequency transfer characteristic of the symbol interpolation filter 24 in which the frequency shift amount of the frequency transfer characteristic is controlled by the processing of the filter control unit 27 described with reference to FIG.
- the symbol interpolation filter 24 filters the transmission path characteristics observed at the SP signal position shown in Fig. 8 (c), so that the transmission path characteristics applied to the received signal output by the AFC unit 4 shown in Fig. 8 (b). Is estimated.
- Fig. 8 (e) shows the component of the desired channel characteristics among the channel characteristics observed at the SP signal position shown in Fig. 8 (c) (the AFC section 4 shown in Fig. 8 (b)).
- the transmission path characteristics obtained by filtering the transmission path characteristics of the received signal output by the symbol interpolation filter 24 are expressed in terms of spectral density.
- Fig. 8 (f) shows the components blocked by filtering the desired channel characteristics component of the channel characteristics observed at the SP signal position shown in Fig. 8 (c) by the symbol interpolation filter 24. It is expressed in spectral density. From FIGS. 8 (e) and (f) and FIGS. 19 (e) and (f) of the conventional example, it can be seen that the components missing from the desired transmission line characteristics are small compared to the conventional example.
- Fig. 8 (g) shows the component of the channel characteristic due to aliasing among the channel characteristics observed at the SP signal position shown in Fig. 8 (c) (SP signal shown in Fig. 8 (c)).
- the desired transmission path characteristics shown in Fig. 8 (b) are removed from the observed transmission path characteristics !, and the transmission path characteristics obtained by filtering with the symbol interpolation filter 24 are filtered. It is expressed in spectral density.
- symbol compensation is achieved compared to the conventional example. It can be seen that the aliasing component output from the inter-filter 24 is small.
- the component force S in Figs. 8 (f) and 8 (g) is smaller than that in the conventional example, so that the error in estimating the channel characteristics at the data modulation signal position is reduced, etc. It is possible to reduce demodulation errors in the conversion unit 7.
- a propagation environment that receives multiple specular waves simultaneously such as a multipath propagation environment in which the reflected wave includes a specular wave, and an SFN (Single Frequency Network) environment that uses the multipath tolerance of the OFDM transmission method.
- a multipath propagation environment in which the reflected wave includes a specular wave and an SFN (Single Frequency Network) environment that uses the multipath tolerance of the OFDM transmission method.
- SFN Single Frequency Network
- the filter control unit 27a that controls the frequency shift of the frequency transfer characteristic of the symbol interpolation filter 24 is different from the filter control unit 27 of the first embodiment. This is substantially the same as the embodiment.
- FIG. 9 is a configuration diagram of the filter control unit 27a of the present embodiment.
- components having substantially the same functions as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description of the first embodiment is provided. The explanation is omitted because it is applicable.
- the filter control unit 27a includes a CP signal extraction unit 41, a CP signal generation unit 42, a transmission path characteristic calculation unit 43, a filter setting unit 44, a symbol filter 45, a delay unit 51, and a difference calculation.
- the delay unit 51 includes the time until the output signal of the transmission path characteristic calculation unit 43 is input to the difference calculation unit 52 via the symbol filter 45 and the time until the output signal is input to the difference calculation unit 52 via the delay unit 51.
- the signal input from the transmission path characteristic calculation unit 43 is delayed and output to the difference calculation unit 52 so that the time is equal.
- the difference calculation unit 52 receives an input signal (symbol filter) input from the symbol filter 45.
- the power value calculation unit 46 a calculates the power value of the output signal of the difference calculation unit 52 (difference value calculated by the difference calculation unit 52), and outputs the calculation result to the minimum value detection unit 53.
- the minimum value detection unit 53 observes the output signal of the power value calculation unit 46a (the power value calculated by the power value calculation unit 46a) and detects the minimum value of the output signal. Then, the minimum value detecting unit 53 symbolically interpolates the frequency control signal indicating the value of ⁇ indicated by the filter setting information input from the filter setting unit 44 when the output signal of the power value calculating unit 46a is the minimum value. Output to filter 24.
- the symbol interpolation filter 24 receives the frequency control signal input from the minimum value detection unit 53 in the filter control unit 27a, and sets the value of ⁇ of each phase rotation unit in the symbol interpolation filter 24 to a value indicated by the frequency control signal. Thus, the frequency transfer characteristic is frequency shifted. Then, the symbol interpolation filter 24 filters the transmission line characteristic input from the transmission line characteristic calculation unit 23 based on the frequency transfer characteristic after the frequency shift, and outputs the filtered characteristic to the carrier interpolation filter 25.
- FIG. 10 is a diagram for explaining the operation of the filter control unit 27a of FIG.
- the horizontal axis represents the frequency normalized by the symbol frequency f.
- the vertical axis represents the spectral density (dB)
- the vertical axis represents the gain (dB).
- Fig. 10 (a) shows the time variation of the transmission path characteristics observed by the CP signal in terms of spectral density, that is, the transmission path characteristics input from the transmission path characteristics calculation unit 43 to the symbol filter 45. It represents the spectral density. However, the ability of CP signals to be transmitted every symbol, aliasing components appear at symbol frequency f intervals, and only the equivalent of symbol frequency f is shown in Fig. 10 (a), where aliasing components appear! / Cunning Les.
- the filter setting unit 44 should set the shift amount (frequency shift amount of the frequency transfer characteristic) for shifting the frequency transfer characteristic of the symbol filter 45 to f 2 ⁇ ⁇ / f (r
- the filter setting information is the symbol filter 45 and the minimum value detector 5 Output to each of 3.
- the symbol filter 45 indicates the value of ⁇ of each phase rotation unit in the symbol filter 45 according to the filter setting information input from the filter setting unit 44.
- the transmission path characteristics whose spectral density is shown in Fig. 10 (a) are filtered by the symbol filter 45 whose frequency transfer characteristics are shown in Fig. 10 (b-1).
- the spectral density of the transmission path characteristics filtered by the symbol filter 45 is as shown in Fig. 10 (c-1).
- the difference calculation unit 52 receives the input signal from the symbol filter 45 (Fig. 10 (c-1)).
- the difference between the signal related to the transmission path characteristics indicating the spectral density) and the input signal from the delay unit 51 (the signal having the same spectral density as that shown in FIG. 10A) is calculated, and the calculation result is output. It is output to the power value calculation unit 46a as a force signal.
- the spectral density of the output signal of the difference calculation unit 52 is as shown in Fig. 10 (d-1).
- the power value calculation unit 46a calculates the power value of the output signal of the difference calculation unit 52, that is, the power value of the signal whose spectral density is shown in Fig. 10 (d-1), and minimizes the calculated power value. Output to the value detector 53.
- the minimum value detection unit 53 internally holds the value of ⁇ (2 ⁇ ⁇ / f) indicated by the filter setting information input from the filter setting unit 44 as ⁇ and
- the power value input from calculation unit 46a is stored internally as P.
- the filter setting unit 44 sets the frequency shift amount of the frequency transfer characteristic of the symbol filter 45 to f, and sets filter setting information with 2 / f (radian) as the value of ⁇ . Shin
- the symbol filter 45 sets the value of ⁇ of each phase rotation unit in the symbol filter 45 to 2 / f (radian) indicated by the filter setting information, Frequency transfer characteristic is shifted by frequency f.
- the transmission path characteristics whose spectral density is shown in Fig. 10 (a) are filtered by the symbol filter 45 whose frequency transfer characteristics are shown in Fig. 10 (b-2).
- the difference calculation unit 52 shown in Fig. 10 (c-2) shows the spectral density of the input signal from the symbol filter 45 (Fig. 10 (c-2)).
- Output to calculation unit 46a The spectral density of the output signal of the difference calculation unit 52 is as shown in Fig. 10 (d-2).
- the power value calculation unit 46a calculates the power value of the output signal of the difference calculation unit 52, that is, the power value of the signal whose spectral density is shown in Fig. 10 (d-2), and minimizes the calculated power value. Output to the value detector 53. Then, the minimum value detection unit 53 compares the power value input from the power value calculation unit 46a with the internally stored P value. Here, the minimum value detection unit 53 inputs the power value from the power value calculation unit 46a.
- Minimum value detection unit 53 is filter setting unit 4 mm
- ⁇ value (2 ⁇ ⁇ / f) indicated by the filter setting information input from 4 is stored internally as ⁇
- the power value input from the power value calculation unit 46a is internally held as P.
- the filter setting unit 44 sets the frequency shift amount of the frequency transfer characteristic of the symbol filter 45 to f, and sets filter setting information with 2 / f (radian) as the value of ⁇ . Shin
- the symbol filter 45 sets the value of ⁇ of each phase rotation unit in the symbol filter 45 to 2 / f (radian) indicated by the filter setting information, Frequency transfer characteristic is shifted by frequency f.
- the transmission path characteristics whose spectral density is shown in Fig. 10 (a) are filtered by the symbol filter 45 whose frequency transfer characteristics are shown in Fig. 10 (b-3).
- the spectral density of the transmission path characteristics filtered by the symbol filter 45 is as shown in Fig. 10 (c-3).
- the difference calculation unit 52 receives the input signal from the symbol filter 45 (Fig. 10 (c-3)).
- the difference between the signal related to the transmission path characteristics indicating the spectral density) and the input signal from the delay unit 51 (the signal having the same spectral density as that shown in FIG. 10A) is calculated, and the calculation result is output. It is output to the power value calculation unit 46a as a force signal.
- the spectral density of the output signal of the difference calculation unit 52 is as shown in Fig. 10 (d-3).
- the power value calculation unit 46a calculates the power value of the output signal of the difference calculation unit 52, that is, the power value of the signal whose spectral density is shown in Fig. 10 (d-3), and minimizes the calculated power value. Output to the value detector 53. Then, the minimum value detection unit 53 compares the power value input from the power value calculation unit 46a with the internally stored P value. Here, the minimum value detection unit 53 inputs the power value from the power value calculation unit 46a.
- the minimum value detection unit 53 sets the value of ⁇ to 2 ⁇ ⁇ min min 1
- the minimum value detection unit 53 performs frequency control indicating 2 ⁇ f / f indicated by ⁇ as the value of ⁇ .
- the control signal is output to the symbol interpolation filter 24.
- the symbol interpolation filter 24 sets the value of ⁇ of each phase rotation unit in the symbol interpolation filter 24 to 2 / f indicated by the frequency control signal. Symbol interpolation filter 24 frequency
- F is the three types of force S, and the number of frequency shifts is not limited to the above.
- the filter control unit 27b that controls the frequency shift of the frequency transfer characteristic of the symbol interpolation filter 24 is different from the filter control unit 27 of the first embodiment. This is substantially the same as the embodiment.
- the filter control unit 27 of the first embodiment calculates the transmission path characteristics of each symbol using the CP signal included in the received signal after the Fourier transform, and uses the calculated transmission path characteristics to determine the symbol Controls the frequency shift of the frequency transfer characteristic of the interpolation filter 24.
- the filter control unit 27b of the present embodiment calculates the transmission path characteristics of each symbol by using a rare OrcC (Transmission and Multiplexing Configuration Control) signal as the received signal after Fourier transform.
- the frequency shift of the frequency transfer characteristic of the symbol interpolation filter 24 is controlled using the calculated transmission line characteristic.
- FIG. 11 is a schematic diagram showing the signal arrangement of SP signals and TMCC signals in the ISDB-T system.
- the vertical axis represents the time in symbol units
- the horizontal axis represents the frequency in carrier units.
- the black circles are SP signals
- the triple circles are TMCC signals
- the white circles are data modulation signals modulated by transmission data.
- the SP signal is a signal BPSK-modulated with a predetermined amplitude and a predetermined phase on the transmission side, and the predetermined amplitude and the predetermined phase are known on the reception side.
- the SP signal is arranged for every 12 carriers in one symbol, shifted by 3 carriers for each symbol, and arranged and transmitted so as to circulate in 4 symbols.
- the TMCC signal is a signal that is DBPSK (Differential Binary Phase Shift Keying) modulated between symbols by control information such as transmission parameters.
- the TMCC signal is arranged for each symbol on a plurality of carriers different from the carrier on which the SP signal is arranged, and all the TMCC signals arranged in a plurality of carriers in one simponore transmit the same control information.
- FIG. 12 is a configuration diagram of the filter control unit 27b of the present embodiment.
- components having substantially the same functions as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description of the first embodiment is provided. The explanation is omitted because it is applicable.
- the filter control unit 27b includes a TMCC signal extraction unit 61, a TMCC decoding unit 62, a TMCC remodulation unit 63, a transmission path characteristic calculation unit 64, a filter setting unit 44, a symbol filter 45, and a power value.
- a calculation unit 46 and a maximum value detection unit 47 are included.
- the received signal after the Fourier transform by the Fourier transform unit 6 is supplied to the TMCC signal extraction unit 61.
- the TMCC signal extraction unit 61 extracts the received signal power TMCC signal after the Fourier transform input from the Fourier transform unit 6, and sends the extracted TMCC signal to the TMCC decoding unit 62 and the transmission path characteristic calculation unit 64, respectively. Output.
- the TMCC decoding unit 62 decodes the control information transmitted by the TMCC signal based on the TMCC signal input from the TMCC signal extraction unit 61, and outputs the control information to the TMCC remodulation unit 63.
- the TMCC decoding unit 62 is based on a plurality of decoded control information in one symbol! / Determine the majority of the transmitted control information and specify the transmitted control information. Thereby, the decoding accuracy of the control information is improved.
- TMCC remodulator 63 performs DB PSK modulation based on the control information input from TMCC decoder 62, estimates the modulation phase of the TMCC signal on the transmission side, and transmits the signal obtained by DBPSK modulation Output to the road characteristic calculation unit 64.
- the transmission path characteristic calculation unit 64 divides the TMCC signal input from the TMCC signal extraction unit 61 by the signal input from the TMCC remodulation unit 63 corresponding to the TMCC signal, and outputs the division result to the symbol filter 45. .
- the division result is the transmission path characteristic at the position where the TMCC signal extracted by the TMCC signal extraction unit 61 is arranged.
- the transmission path characteristics of each symbol are estimated and estimated by the processes of the TMCC signal extraction section 61, the TMCC decoding section 62, the TMCC re-modulation section 63, and the transmission path characteristics calculation section 64.
- the transmission line characteristics are output by the symbol filter 45.
- the frequency shift amount of the frequency transfer characteristic is set by the filter setting unit 44.
- the transmission path characteristic output from transmission path characteristic calculation section 64 is filtered by symbol filter 45 and input to power value calculation section 46.
- the power value calculation unit 46 calculates the power value of the signal after filtering by the simpo filter 45, and outputs the calculated power value to the maximum value detection unit 47.
- the processing of each unit of the filter setting unit 44, the symbol filter 45, and the power value calculation unit 46 is performed with respect to a plurality of frequency shift amounts of the frequency transfer characteristics of the symbol filter 45.
- Maximum value detector 47 observes the output signal of power value calculator 46 (the power value calculated by power value calculator 46) and detects the maximum value of the output signal. The maximum value detection unit 47 then outputs a frequency control signal indicating the value of ⁇ indicated by the filter setting information input from the filter setting unit 44 to the symbol interpolation filter 24 when the output signal has the maximum value.
- ⁇ Fourth embodiment >>
- the filter control unit 27c that controls the frequency shift of the frequency transfer characteristic of the symbol interpolation filter 24 is different from the filter control unit 27a of the second embodiment. Is substantially the same as in the second embodiment.
- the filter control unit 27a calculates the transmission path characteristics of each symbol using the CP signal included in the received signal after the Fourier transform, and uses the calculated transmission path characteristics to convert the symbol interpolation filter 24a. Controls the frequency shift of the frequency transfer characteristic of the.
- the filter control unit 27c of the present embodiment calculates the transmission path characteristics of each symbol using the TMCC signal included in the received signal after the Fourier transform, and uses the calculated transmission path characteristics.
- the frequency shift of the symbol interpolation filter 24 is controlled.
- FIG. 13 is a configuration diagram of the filter control unit 27c of the present embodiment.
- components having substantially the same functions as those in the first to third embodiments are denoted by the same reference numerals as those in the first to third embodiments, and the first Since the description of the third embodiment can be applied, the description thereof is omitted.
- the filter control unit 27c includes a TMCC signal extraction unit 61, a TMCC decoding unit 62, a TMCC remodulation unit 63, a transmission path characteristic calculation unit 64, a filter setting unit 44, a symbol filter 45, and a delay unit. 51, a difference calculation unit 52, a power value calculation unit 46a, and a minimum value detection unit 53.
- the transmission path characteristics of each symbol are estimated and estimated by the processes of the TMCC signal extraction section 61, the TMCC decoding section 62, the TMCC re-modulation section 63, and the transmission path characteristics calculation section 64.
- the transmission path characteristics are output to the symbol filter 45.
- the frequency shift amount of the frequency transfer characteristic is set by the filter setting unit 44.
- the transmission line characteristic output from the transmission line characteristic calculation unit 64 is filtered by the symbol filter 45 and input to the difference calculation unit 52, and is delayed by the delay unit 51 and input to the difference calculation unit 52.
- the difference calculation unit 52 receives the signal from the symbol filter 45.
- the difference between the input signal and the input signal from the delay unit 51 is calculated, and the calculation result is output as an output signal to the power value calculation unit 46a.
- the power value calculation unit 46 a calculates the power value of the output signal of the difference calculation unit 52 and outputs the calculated power value to the minimum value detection unit 53.
- the processes of the filter setting unit 44, the symbol filter 45, the delay unit 51, the difference calculation unit 52, and the power value calculation unit 46a are performed for a plurality of frequency shift amounts of the frequency transfer characteristics of the symbol filter 45.
- the minimum value detection unit 53 observes the output signal of the power value calculation unit 46a (the power value calculated by the power value calculation unit 46a) and detects the minimum value of the output signal. Then, the minimum value detection unit 53 outputs a frequency control signal indicating the value of ⁇ indicated by the filter setting information input from the filter setting unit 44 to the symbol interpolation filter 24 when the output signal is minimum.
- ⁇ Fifth embodiment >>
- the shift amount by which the frequency transfer characteristic of the symbol interpolation filter is frequency-shifted is controlled.
- the AFC unit 4a controls the shift amount by which the received signal is frequency-shifted.
- FIG. 14 is a configuration diagram of the receiving device la according to the present embodiment, and is a configuration example of a receiving device that receives terrestrial digital television broadcasting using the OFDM transmission scheme.
- components having substantially the same functions as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description of the first embodiment can be applied. Therefore, the explanation is omitted.
- the receiving device la includes an antenna 2, a tuner 3, an AFC unit 4a, a symbol synchronization unit 5, a family conversion unit 6, an equalization unit 7a, an error correction unit 8, and a video / audio decoding unit.
- Unit 9 display unit 10, speaker 11, and AFC control unit 12.
- the AFC unit 4a removes the frequency error generated when the broadcast wave is selected from the received signal input from the tuner 3, and outputs the received signal from which the frequency error has been removed to the symbol synchronization unit 5 and the Fourier transform unit 6, respectively. .
- the AFC unit 4a is a frequency control input from the AFC control unit 12.
- the received signal input from tuner 3 is frequency shifted based on the value indicated by the control signal.
- Equalizing section 7a estimates the transmission path characteristics based on the received signal input from Fourier transform section 6, and equalizes and demodulates the received signals based on the estimated transmission path characteristics. Then, the equalizing unit 7a outputs the demodulated received signal to the error correcting unit 8.
- the equalization unit 7a can be realized, for example, by a configuration in which the filter control unit 27 is removed from the equalization unit 7 whose configuration is shown in FIG.
- the AFC control unit 12 includes a CP signal extraction unit 41, a CP signal generation unit 42, a transmission path characteristic calculation unit 43, a filter setting unit 44, a symbol filter 45, a power value calculation unit 46, and a maximum value detection unit. 47.
- the maximum value detection unit 47 outputs the frequency control signal to the AFC unit 4a instead of outputting to the symbol interpolation filter 24.
- the maximum value detection unit 47 outputs the frequency control signal to the AFC unit 4a instead of outputting it to the symbol interpolation filter 24, the CP signal extraction unit 41, the CP signal generation unit 42, and the transmission path characteristic calculation
- Each unit of the unit 43, the filter setting unit 44, the symbol filter 45, the power value calculation unit 46, and the maximum value detection unit 47 performs substantially the same processing as in the first embodiment.
- the present invention is not limited to the above-described embodiment.
- the following may be used.
- the configuration of the symbol interpolation filter 24 and the symbol filter 45 may be a filter configuration method such as a polyphase filter that is not limited to the configuration illustrated in FIG.
- symbol interpolation filter 24 is Since the transmission line characteristics are once every four symbols, it is necessary to use a four-phase polyphase filter.
- the power that the symbol interpolation filter 24 and the symbol filter 45 have the same structure is used.
- the symbol filter 45 is not limited to this.
- the symbol filter 45 transmits the same frequency as the symbol interpolation filter 24. What is necessary is just to be able to implement
- the filter controllers 27b and 27c are transmitted by the ISDB-T system. Power using signals
- a TPS (Transmission Parameter Signaling) signal transmitted in DVB-T format may be used for IJ.
- the TPS signal is a signal that is differentially BPSK-modulated between symbols by control information such as transmission parameters.
- the TPS signal is arranged for each symbol on a plurality of carriers different from the carrier on which the SP signal is arranged, and the TMCC signals arranged on the plurality of carriers in one symbol all have the same control information.
- the transmission path characteristics are estimated from the received signal, and the frequency shift of the frequency transfer characteristics of the symbol interpolation filter 24 is controlled using the estimated transmission path characteristics. If possible, the present invention is applicable.
- the TMCC decoding unit 62 makes a majority decision on the control information transmitted by the TMCC signal based on a plurality of decoded control information in one symbol, For example, the following may be used as the force S for specifying the control information transmitted by the TMCC signal.
- the TMCC decoding unit 62 combines TMCC signals arranged on a plurality of carriers in one symbol, and decodes the TMCC signal using the combined TMCC signal.
- the TMCC decoding unit 62 selects a TMCC signal having good reception quality from among a plurality of TMCC signals in one symbol, decodes the TMC C signal using the selected TMCC signal, and transmits the control using the TMCC signal. Identify information.
- the TMCC decoding unit 62 decodes a TMCC signal of a predetermined carrier and specifies control information transmitted by the TMCC signal.
- the frequency transfer characteristics of the symbol interpolation filter 24 are This is the case where only the wave number shift is performed, but it is also possible to perform both the change of the pass bandwidth of the frequency transfer characteristic of the symbol interpolation filter 24 and the frequency shift of the frequency transfer characteristic. Can be realized.
- the filter control unit sequentially changes the pass bandwidth of the symbol filter 24 to a plurality of predetermined pass bandwidths, and obtains an optimum frequency shift amount for each pass bandwidth.
- the equalization unit 7 performs equalization processing on the combination of the pass bandwidth and frequency shift amount obtained above with the pass bandwidth and frequency shift amount of the symbol interpolation filter 24, and the received quality Select the combination of the best passband width and frequency shift amount.
- the reception quality is determined by, for example, observing the error from the modulation point of the demodulated signal obtained by the equalization unit 7 and the error rate of the input or output of the error correction unit 8.
- the filter control unit has a frequency shift amount range in which the power of the output signal of the symbol filter falls within a predetermined range with respect to the power of the output signal of the symbol filter obtained by the determined optimum frequency shift amount.
- the frequency shift range obtained above is in the range of f to f.
- the filter control unit controls the frequency shift amount of the frequency transfer characteristic of the symbol interpolation filter 24 based on the frequency abab shift amount, which is the average of f and f, and the symbol interpolation filter 24 based on the frequency difference between f and f.
- the filter control unit internally retains the plurality of Doppler frequencies in association with the Doppler frequency and the coefficient of the symbol interpolation filter 24 that determines the pass bandwidth.
- the filter control unit estimates the Doppler frequency using the SP signal, CP signal, TMCC signal or TPS signal in the received signal, and supplies the coefficient corresponding to the estimated Doppler frequency to the symbol interpolation finalizer 24 and the symbol filter 45. Set. Thereafter, the frequency shift amount of the frequency transfer characteristic of the symbol interpolation filter 24 is determined as described in the first to fourth embodiments, and based on the determined frequency shift amount! / Controls the frequency shift of the frequency transfer characteristics of the symbol interpolation filter 24.
- FIG. 15 is a diagram for explaining the effect of performing both the change of the pass bandwidth of the frequency transfer characteristic of the symbol interpolation filter 24 and the frequency shift.
- the horizontal axis represents the frequency normalized by the symbol frequency f.
- the vertical axis represents the spectral density (dB).
- the vertical axis represents the gain. (DB).
- the symbol frequency f is
- Fig. 15 (a) shows the time variation of the channel characteristics observed by the SP signal in terms of spectral density, that is, the channel characteristics input from the channel characteristics calculator 23 to the symbol interpolation filter 24. It represents the spectral density. Show the case where the spread of the spectral density is low and the moving speed of the receiver is low.
- FIG. 15 (b-1) shows the frequency transfer characteristic of the symbol interpolation filter 24 in which the frequency shift amount of the frequency transfer characteristic and the pass bandwidth of the frequency transfer characteristic are controlled by the processing of the filter control unit.
- Figure 15 (c-1) shows the transmission path characteristics observed at the SP signal position shown in Figure 15 (a).
- the transmission path characteristics obtained by filtering with the symbol interpolation filter 24 of the frequency transfer characteristics in 1) are represented by spectral density.
- FIG. 15 (b-2) shows the frequency transfer characteristic of the symbol interpolation filter 24 in which only the pass bandwidth of the frequency transfer characteristic is controlled as in the conventional example.
- the pass bandwidth of the frequency transfer characteristics in Fig. 15 (b-2) is the same as the pass bandwidth of the frequency transfer characteristics in Fig. 15 (b-1).
- Fig. 15 (c-2) the transmission path characteristics observed at the SP signal position shown in Fig. 15 (a) are filtered by the symbol interpolation filter 24 of the frequency transfer characteristics shown in Fig. 15 (b-2).
- the transmission line characteristics obtained in Fig. 1 are represented by spectral density.
- the transmission path characteristics output from the symbol interpolation filter 24 are missing the low-frequency component of the desired transmission path characteristics.
- Figure 15 (c-3) is obtained by filtering the transmission path characteristics observed at the SP signal position shown in Figure 15 (a) by the symbol interpolation filter 24 of the frequency transfer characteristics shown in Figure 15 (b-3).
- the transmission path characteristics are represented by spectral density.
- the pass bandwidth of the frequency transfer characteristic of the symbol interpolation filter 24 can be selected appropriately.
- the configuration of the AFC control unit of the fifth embodiment for example, the configuration of the filter control unit 27a of the second embodiment, the configuration of the filter control unit 27b of the third embodiment, or The configuration of the filter control unit 27c of the fourth embodiment can be used.
- the maximum value detection unit 47 of the filter control unit 27b outputs the frequency control signal to the AFC unit 4a instead of outputting it to the symbol interpolation filter 24.
- the minimum value detection unit 53 of the filter control units 27a and 27c outputs the frequency control signal to the AFC unit 4a instead of outputting to the symbol interpolation filter 24.
- the first to fourth AFC units 4 and the AFC unit 4a of the fifth embodiment are not limited to the configuration shown in FIG. 2, for example, the pilot signal in the received signal A configuration in which a frequency error generated when a broadcast wave is selected from the received signal based on the phase change may be removed.
- the receiving apparatus may be realized as an LS Large Scale Integration) that is typically an integrated circuit.
- Each circuit may be individually made into one chip, or may be made into one chip so as to include all or some of the circuits.
- the tuner 3 may be integrated on the same integrated circuit as other circuit units, or may be a separate integrated circuit.
- IC Integrated Circuit
- system LSI system LSI
- super LSI unoretra LSI, depending on the difference in power integration described as LSI.
- the method of circuit integration is not limited to LSIs. It may be realized with.
- FPGA Field Programmable Gate Array
- FPGA Field Programmable Gate Array
- the present invention relates to a receiving device that receives a signal of a multicarrier transmission system, for example, a terrestrial digital revision such as an ISDB-T system or a DVTB T system that employs an OFDM transmission system that is one of the multicarrier transmission systems. It can be applied to receivers that receive broadcasts.
- a multicarrier transmission system for example, a terrestrial digital revision such as an ISDB-T system or a DVTB T system that employs an OFDM transmission system that is one of the multicarrier transmission systems. It can be applied to receivers that receive broadcasts.
- the present invention can be applied to a receiving apparatus that receives a signal of a single carrier transmission system.
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- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Power Engineering (AREA)
- Quality & Reliability (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Artificial Intelligence (AREA)
- Circuits Of Receivers In General (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
- Channel Selection Circuits, Automatic Tuning Circuits (AREA)
- Noise Elimination (AREA)
Description
Claims
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JP2008530840A JP5020246B2 (ja) | 2006-08-21 | 2007-07-30 | 受信装置、集積回路及び受信方法 |
EP07791581.7A EP2056499B1 (en) | 2006-08-21 | 2007-07-30 | Receiver, integrated circuit, and reception method |
US12/307,783 US8275056B2 (en) | 2006-08-21 | 2007-07-30 | Receiver, integrated circuit, and reception method |
CN2007800270757A CN101496324B (zh) | 2006-08-21 | 2007-07-30 | 接收装置、集成电路及接收方法 |
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EP (1) | EP2056499B1 (ja) |
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WO2008129825A1 (ja) * | 2007-03-27 | 2008-10-30 | Panasonic Corporation | Ofdm受信装置、ofdm受信方法、ofdm受信回路、集積回路、及びプログラム |
WO2009125592A1 (ja) * | 2008-04-11 | 2009-10-15 | パナソニック株式会社 | 受信装置、集積回路、デジタルテレビ受像機、受信方法、及び受信プログラム |
JP2011234105A (ja) * | 2010-04-27 | 2011-11-17 | Sharp Corp | 受信装置、基地局装置、無線通信システム、伝搬路推定方法、制御プログラムおよび集積回路 |
EP2290857A4 (en) * | 2008-06-16 | 2016-05-11 | Panasonic Ip Corp America | RECEPTION DEVICE, INTEGRATED CIRCUIT, DIGITAL TELEVISION RECEIVER, RECEIVING METHOD, AND RECEIVING PROGRAM |
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WO2011042066A1 (en) * | 2009-10-09 | 2011-04-14 | Nokia Corporation | Symbol index identification employing scrambling sequences |
CN102281216B (zh) * | 2010-06-11 | 2014-05-07 | 联芯科技有限公司 | 正交频分复用系统中下行信道估计的方法和装置 |
US8432498B2 (en) * | 2010-10-20 | 2013-04-30 | Stmicroelectronics Asia Pacific Pte Ltd. | Automatic frequency selection for peaking |
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CN101496324A (zh) | 2009-07-29 |
EP2056499A4 (en) | 2016-03-02 |
JPWO2008023539A1 (ja) | 2010-01-07 |
US20090207956A1 (en) | 2009-08-20 |
EP2056499A1 (en) | 2009-05-06 |
JP5020246B2 (ja) | 2012-09-05 |
US8275056B2 (en) | 2012-09-25 |
CN101496324B (zh) | 2012-05-16 |
EP2056499B1 (en) | 2018-12-05 |
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