DE112010005148B4 - Digital broadcast receiver and delay profile generation method - Google Patents

Abstract

A digital broadcast receiver for receiving an orthogonal frequency division multiplex signal, the digital broadcast receiver comprising: a Fourier transform unit (2) for performing a Fourier transform on the received orthogonal frequency division multiplex signal on a per transmission unit basis; a subcarrier power calculating unit (9) for calculating subcarrier power data from data which the Fourier transform unit (2) obtains by performing the Fourier transform on the received orthogonal frequency division multiplex signal; a first inverse Fourier transform unit (10a) for performing an inverse Fourier transform on the sub-carrier power data calculated by the sub-carrier power calculation unit (9) to generate a first delay profile; a pilot signal extraction unit for extracting a pilot signal from the data which the Fourier transform unit (2) obtains by performing the Fourier transform on the received orthogonal frequency division multiplex signal; a dividing unit (5) for dividing the pilot signal extracted by the pilot signal extraction unit (3) by a known value to calculate transmission line characteristic data for the pilot signal provided on a per transmission unit basis; a time direction interpolation unit (6) for interpolating intermediate data in a time direction between the transmission line characteristic data all calculated for the pilot signal provided on a per transmission unit basis by the dividing unit (5); a second inverse Fourier transform unit (10b) for performing an inverse Fourier transform on the transmission line characteristic data into which the intermediate data is interpolated in the time direction by the time direction interpolation unit (6) to generate a second delay profile; and ...

Description

FIELD OF THE INVENTION

The present invention relates to a digital broadcast receiver and a delay profile generating method of receiving a digital broadcast wave using an OFDM (Orthogonal Frequency Division Multiplexing) method.

BACKGROUND OF THE INVENTION

In an OFDM system, information to be transmitted is assigned to a plurality of subcarriers and digital modulation is performed on each of the subcarriers. For example, a QPSK (Quadrature Phase Shift Encrypt) method, a QAM (Quadrature Amplitude Modulation) method, and a Multi-value PSK (Phase Shift Encryption) method may be provided as a digital modulation method.

Further, a known signal is multiplexed in a specific subcarrier, and a receiving side demodulates the subcarrier using this known signal.

On the other hand, the subcarrier in which the known signal is multiplexed is orthogonally transformed via an inverse Fourier transform process, and is sent after the frequency of the subcarrier is converted to a desired transmission frequency. Each transmission unit on which this inverse Fourier transform process is performed is referred to as a symbol.

A copy of the rearmost part of the signal on which the inverse Fourier transform process is performed is generated and the copy is added to the head of each symbol. The added part is called a wake interval. Even if there is an incoming wave having a delay time equal to or shorter than the guard interval length, the receiving side can reproduce the signal without any interference between symbols.

An ISDB-T method, which is a digital terrestrial broadcasting method used in Japan, and taking a DVB-T method used in Europe as examples, the known signal which is preliminarily inserted in the transmission signal, a scattered pilot signal SP (ab now called an SP signal). This SP signal is periodically inserted into the transmission signal.

The receiving side previously has the value of each SP signal which is periodically inserted in the transmission signal as a known SP signal, and can the variation amount in the amplitude of each SP signal and the variation amount in the phase of each SP signal (which from now estimating conduction characteristic) by dividing each received SP signal by the known SP signal (hereinafter referred to as transmission line estimation).

Furthermore, the receiving side can determine a delay profile showing the intensity of the received signal for each arrival time by performing an inverse Fourier transform on the value of these line characteristics. In this case, the delay profile determined from the transmission line attribute values is referred to as an SP base delay profile.

As another method for determining a delay profile, there is a method that uses a power spectrum of the received signal (see, for example, Patent Reference 1). According to this method, the value of the received signal is squared in a frequency domain, and an inverse Fourier transform is performed on the square after that square is converted into an electric power dimension value, so that a delay profile is determined. In this case, this delay profile is referred to as an electrical power base delay profile.

When the effective symbol length is expressed as Ts, the electric power base delay profile has a maximum delay time interval of Ts / 2 during which incoming waves can be detected, and the length of this delay time interval is longer than that of a delay time interval of ± Ts / 6 of the SP. base delay profile.

However, it is a problem that the electric power base delay profile only provides the relative time difference between an advanced wave and a delayed wave for a main wave, and therefore the discrimination between an advanced wave and a delayed wave can not be made. Another problem is that if there are a plurality of incoming waves, cross-modulation occurs due to interference between incoming waves and an incoming wave, which does not originally exist, appears on the delay profile.

On the other hand, Patent Reference 2 discloses an OFDM wave delay profile measuring apparatus which has a combination of a delay profile equivalent to such an SP base delay profile as mentioned above and based on a transfer function method and method Delay profile equivalent to such electric power base delay profile as mentioned above and used based on a power spectrum method. By using the two delay profiles, this device can measure the length of a maximum delay time interval during which delayed waves can be measured, a temporal resolution at which delayed waves can be measured, a level at which delayed waves can be measured, the accuracy of the delayed one Eliminate wave levels and a false impulse response in a method of measuring the delay profiles.

However, it is a problem that because an incoming wave appearing only on the delay profile (SP base delay profile) is outputted as a measurement result based on the transfer function method, it is the same as it is at the time of a moving one Object in which the receiver is mounted, moves at high speed, occurring, incoming pseudo-wave can not be deleted.

An OFDM receiver described in Patent Reference 3 prevents erroneous control at the time when a moving object in which the receiver is mounted travels at a high speed by causing an incoming pseudo-wave to occur at the time when the moving object is moved at a high speed, evaluated.

However, there is a problem that the time interval during which incoming waves can be detected is limited to ± Ts / 6, there is a possibility that erroneous control for an incoming wave having a long delay time is performed.

Furthermore, the receiver described in Patent Reference 3 has no function of outputting a correct delay profile by not displaying an incoming pseudo-wave.

The present invention has been made to solve the above-mentioned problems, and it is therefore an object of the present invention to provide a digital broadcast receiver and a delay profile generation method capable of providing a delay profile without error, to erroneous control and to improve the reception capabilities even in an environment in which a moving object in which the digital broadcast receiver is mounted moves at a high speed, and even if an incoming wave having an input time which is not in the Period falls during which incoming waves can be detected, appears on an SP base delay profile.

Documents of the prior art

• Patent Reference 1: JP 2005 268831 A
• Patent Reference 2: JP 2006 93760 A
• Patent Reference 3: JP 2008 72224 A

SUMMARY OF THE INVENTION

According to the present invention, there is provided a digital broadcasting receiver including: a Fourier transform unit for performing a Fourier transform on the received orthogonal frequency division multiplexed signal on a per transmission unit basis; a subcarrier power calculating unit for calculating subcarrier power data from data which the Fourier transform unit obtains by performing the Fourier transform on the received orthogonal frequency divider multiplexed signal; a first inverse Fourier transform unit for performing an inverse Fourier transform on the subcarrier power data calculated by the subcarrier power calculating unit to generate a first delay profile; a pilot signal extracting unit for extracting a pilot signal from the data which the Fourier transform unit obtains by performing the Fourier transform on the received orthogonal frequency division multiplexed signal; a divider unit for dividing the pilot signal extracted by the pilot signal extraction unit by a known value to calculate transmission line characteristic data for the pilot signal provided on a per-transmission unit basis; a time direction interpolation unit for interpolating intermediate data in a time direction between the transmission line characteristic data, all of which are calculated by the divider unit for the pilot signal provided on a per transmission unit basis; a second inverse Fourier transform unit for performing an inverse Fourier transform on the transmission line characteristic data into which the intermediate data is interpolated in the time direction by the time direction interpolation unit to generate a second delay profile; and a delay profile synthesis unit for offsetting a detection time of each incoming wave of the first delay profile generated by the first inverse Fourier transform unit such that an arrival time of a main wave of the first delay profile matches a main wave of the second delay profile generated by the second inverse Fourier transform unit , and also leaves intact any value contained in the second delay profile , and corresponds to an arrival time corresponding to a value equal to or greater than a predetermined threshold in the first delay profile in which the detection time of each incoming wave is offset, and to replace each of the times in the second delay profile and an arrival time having a value smaller than that, value corresponding to the threshold by a value that is not handled as an incoming wave to output the second delay profile as a delay profile of the received orthogonal frequency division multiplexed signal.

The digital broadcasting receiver according to the present invention can provide a delay profile containing no error as a delay profile of the received orthogonal frequency division multiplexed signal to prevent erroneous control, and improve its reception capability even in an environment where a moving object, in the digital broadcast receiver itself is mounted, moving at a high speed, and even if an incoming wave having an arrival time which does not fall within a detection period in which incoming waves are detected appears in the second delay profile (an SP base delay profile ).

BRIEF DESCRIPTION OF THE FIGURES

1 Fig. 12 is a view showing an arrangement pattern of SP signals in a transmission signal;

2 Fig. 12 is a view showing the result of estimating the line characteristics of SP signals interpolated in a time direction;

3 Fig. 12 is a view showing the result of estimating the line characteristics of SP signals interpolated in the time direction and in the frequency direction;

4 Fig. 13 is a view showing an example of an SP basic delay profile;

5 Fig. 12 is a view showing the result of estimating conduction characteristics including errors using interpolation in the time direction;

6 Fig. 10 is a view showing an SP base delay profile and an incoming pseudo wave occurring in this SP base delay profile;

7 Fig. 12 is a view showing an example of a problem caused by a delayed wave appearing in an SP base delay profile and having a delay time that does not fall within a detection period;

8th Fig. 10 is a view showing an example of an electric power base delay profile;

9 Fig. 10 is a block diagram showing the structure of a digital broadcasting receiver according to Embodiment 1 of the present invention;

10 FIG. 10 is a flowchart showing a flow of operation of a delay profile synthesis unit according to Embodiment 1; FIG.

11 Fig. 12 is an explanatory drawing explaining a process of synthesizing delay profiles according to Embodiment 1;

12 FIG. 10 is a flowchart showing a flow of the operation of a delay profile synthesis unit according to Embodiment 2; FIG.

13 FIG. 4 is an explanatory drawing explaining a process of synthesizing delay profiles according to Embodiment 3; FIG.

14 Fig. 10 is a block diagram showing the structure of a digital broadcasting receiver according to Embodiment 4 of the present invention; and

15 Fig. 10 is a block diagram showing the structure of a digital broadcasting receiver according to Embodiment 5 of the present invention.

EMBODIMENTS OF THE INVENTION

In order to explain this invention in more detail, the preferred embodiments of the present invention will be described with reference to the accompanying drawings.

Embodiment 1

First, SP signals which are inserted into a transmission signal according to an OFDM method, an SP base delay profile and an electric power base delay profile will be explained.

1 FIG. 16 is a view showing a layout pattern of the SP signals in the transmission signal, wherein each black circle symbol shown in FIG 1 shows an SP signal and each white circle symbol shows a signal such as data. As in 1 12, the SP signals are scattered in a time direction at intervals of four symbols and in a frequency direction at intervals of twelve carriers, and are arranged while SP signals in FIG mutually adjacent symbols in time direction are shifted from one another by three carriers in such a way that SP signals in a symbol inserted in the frequency direction have the same positions in the frequency direction every four symbols. The receiving side divides each SP signal received thereby by a known SP signal to estimate the line characteristics of each SP signal.

2 FIG. 13 is a view showing the result of estimating the line characteristics of SP signals determined by the interpolation in the time direction. Each in 2 The black circle symbol shown shows an estimate of the line characteristics of an SP signal, each black triangle symbol shows an estimated value of the line characteristics obtained by interpolation in the time direction, and each white circle symbol shows a signal such as data.

Furthermore is 3 10 is a view showing the result of estimating the line characteristics of SP signals obtained by interpolation in both the time direction and the frequency direction. Each in 3 black circle symbol shown is an estimate of the line characteristics of an SP signal, each black triangle symbol shows an estimate of the line characteristics obtained by the interpolation in time direction, and each black square symbol shows an estimated value of the line characteristics obtained by interpolation is determined in the frequency direction.

After interpolating the estimated values of the line characteristics of SP signals in time direction, as in 2 shown, it allows further interpolation in the frequency direction, as in 3 shown to provide the line characteristics for all subcarriers.

By performing interpolation in the time direction between the estimated values of the line characteristics of SP signals dispersed at intervals of twelve carriers in the frequency direction, as shown in FIG 2 For example, estimated values of the line characteristics at intervals of three carriers in the frequency direction are scattered. As a result, a period during which the line characteristics can be estimated increases from Ts / 12 to Ts / 3 in length, and even in an environment where there is a large difference between arrival times of incoming waves, the line characteristics be correctly estimated as long as the arrival times of incoming waves fall within the extended period.

4 Fig. 13 is a view showing an example of an SP basic delay profile. By performing an inverse Fourier transform on the above-mentioned transmission line characteristic values, the receiver determines a delay profile (SP base delay profile) showing the intensity for each arrival time of the reception signal, as in FIG 4 shown. As in 4 In the case of broadcast using an OFDM signal, the main wave of the received signal is a highest level input wave of the plurality of input waves included in the received signal. Furthermore, a delayed wave and an advanced wave (in 4 not shown) of the main shaft due to a multipath included in the reception signal, coupling loop interference occurring in retransmission, etc. When a moving object (eg, a vehicle) in which the receiver is mounted moves at a high speed, The received signal received by the receiver varies in line characteristic for each symbol under the influence of Doppler variations.

5 FIG. 12 is a view showing the result of estimating the line characteristics including errors occurring in the interpolation in the time direction, each in FIG 5 The black circle symbol shown indicates an estimate of the line characteristics of an SP signal, each cross shows an estimated value of the line characteristics including an error occurring in the interpolation in the time direction, and each white circle symbol shows a signal such as data. When a maximum frequency (also referred to as the maximum Doppler frequency) of variations in line characteristics due to Doppler variations exceeds 1 / ((Ts + Tg) / 8) (Hz), where Ts is the effective symbol length and Tg is the guard interval length representing the high frequency end of the Is range of frequencies in which the interpolation can be performed in time direction, the line characteristics include errors as in 5 and the receiver becomes unable to correctly perform the interpolation in the time direction. The above-mentioned equation showing the maximum frequency which is the high-frequency end of the range of frequencies in which the interpolation can be performed is derived from the same sampling theorem and the fact that SP signals are interpolated every four symbols.

6 is a view showing an SP base delay profile. When an SP basic delay profile is determined from the result, an estimation of a line characteristic in which the interpolation in the time direction is incorrectly performed as in FIG 5 shown due to a high speed movement of the moving object in which the receiver is mounted, For example, input waves that did not originally exist can be detected as input pseudowaves in the delay profile within a period of ± Ts / 6 during the input waves, as in FIG 6 shown. As a result, if the receiver performs erroneous control according to the detection of these incoming pseudo-waves, its receiving ability becomes worse.

Further, when the SP base delay profile has an input wave with a delay time that does not fall within the period of ± Ts / 6, which is the detection period during which input waves are detected, the following malfunctions occur.

7 FIG. 12 is a view showing an example of the malfunctions caused by a delayed wave occurring in the SP basic delay profile and having a delay time later than the detection period during which the input waves are detected. As in 7 When an input wave with a delay time that does not fall within the period of ± Ts / 6 exists, the input wave is convolved with its original delay time and appears in the SP base delay profile as an alias falling within the detection period. Therefore, the input shaft, which is originally a delayed wave, looks like an advanced wave with respect to the main shaft, and the discrimination between an advanced wave and a delayed wave is difficult to hit.

On the other hand, although an electric power base delay profile provides a period of time up to ± Ts / 2, during which input waves can be detected, only the relative time difference between a delayed wave and an advanced wave with respect to the main wave is detected. Therefore, as in 8th As shown, no distinction can be made between an advanced wave and a delayed wave in an electric power base delay profile. Further, when there are a plurality of input waves, cross-modulation occurs in an electric power-base delay profile due to interference between input waves, and an input wave, which does not originally exist, appears on the delay profile.

Because the method disclosed by Patent Reference 1 uses an electric power-base delay profile, the above-mentioned problems occur in methods. Further, while the apparatus disclosed in Patent Reference 2 uses a combination of an SP basic delay profile and an electric power base delay profile, the apparatus provides an input wave appearing only in the SP basic delay profile as a detection result as it is. Therefore, the device can not eliminate incoming pseudo-waves in the SP base delay profile that occur when a moving object in which the device is mounted moves at a high speed. In addition, while the receiver described by Patent Reference 3 prevents the erroneous control by evaluating incoming pseudo-waves that occur when a moving object in which the receiver is mounted moves at a high speed, the time period during which the input shafts are detected are limited to ± Ts / 6, and there is a possibility that erroneous control is performed for an input shaft having a long delay time.

To solve these problems, a digital broadcast receiver according to Embodiment 1 of the present invention uses an electric power base delay profile to cancel an error signal included in an SP base delay profile, and newly generates a delay profile by taking advantage of the effects of both delay profiles in a so-called composite effect from the SP base delay profile by canceling the error signal. In this way, even in an environment in which a moving object in which the receiver is mounted moves at a high speed, and even if an input shaft with a delay time that does not fall within the detection period exists, the digital one Broadcast receivers perform the receive operation correctly without causing errors in the newly generated delay profile and without performing any erroneous control using a conventional delay profile. The details of the receiving operation are explained below.

9 Fig. 10 is a block diagram showing the structure of the digital broadcasting receiver according to Embodiment 1 of the present invention. The digital radio receiver 1 According to Embodiment 1, a digital broadcast wave is received using an OFDM method. As in 9 shown is the digital radio receiver 1 with a Fourier transformation unit 2 , a pilot signal extraction unit 3 , a known signal generation unit 4 , a divider unit 5 , a time direction interpolation unit 6 , a frequency direction interpolation unit 7 an equalizer unit 8th a sub-carrier power calculation unit 9 , a first inverse Fourier transform unit 10a , a second inverse Fourier transform unit 10b and a delay profile synthesis unit 11 Mistake.

The Fourier transformation unit 2 is a component for extracting a time domain signal (a signal on a per transmission unit basis) from the received signal during a symbol period and performing a Fourier transform on the time domain signal to generate a frequency domain signal. Specifically, the Fourier transform unit performs 2 a fast Fourier transform (FFT) on the time domain signal. By performing this Fourier transform on the time domain signal, the Fourier transform unit converts the received time domain signal into signals from subcarriers which are carrier units of the frequency domain signal.

The pilot signal extraction unit 3 is a component for extracting the SP signal inserted in the predetermined sub-carrier position from that by the Fourier transform unit 2 detected signal of each subcarrier. The signal generation unit 4 is a component for generating a known SP signal value corresponding to the predetermined sub-carrier position from which the SP signal is received by the pilot signal extraction unit 3 is extracted. An SP signal of the known value has the value of the SP signal at the time of transmission, and will be referred to as a known SP signal from now on. The divider unit 5 is a component for dividing the value of the value by the pilot signal extraction unit 3 extracted SP signal by the known SP signal value corresponding to the extracted SP signal to determine a transmission line characteristic value.

Because SP signals are inserted into the OFDM signal in such a manner that the SP signals are spread at intervals of 12 carriers, the digital broadcast receiver must perform an interpolation process to determine the line characteristics of all subcarriers. Because the SP signals are arranged in the OFDM signal in the time direction in such a manner that the SP signals are spaced at intervals of four symbols, the receiver first performs an interpolation process in the time direction. The time direction interpolation unit 6 is a component for interpolating intermediate values in the time direction between the transmission line characteristic values provided by the divider unit 5 and performs a time direction interpolation process using linear interpolation, FIR (finite impulse response) filters for a plurality of symbols, or the like. By performing the interpolation process in the time direction, the time direction interpolation unit provides all three carriers with a line characteristic signal in the frequency direction, as in FIG 2 shown.

The frequency direction interpolation unit 7 is a component for performing a frequency direction interpolation process on the time direction interpolation unit 6 determined line characteristic signals using linear interpolation, FIR filter for a plurality of symbols or the like. By performing this frequency direction interpolation process, as in 3 2, the frequency direction interpolation unit determines the line characteristics for all subcarriers. The equalizer unit 8th is a component for dividing the signal each by the Fourier transform unit 2 detected subcarrier by the transmission line characteristic value of each subcarrier, by the frequency direction interpolation unit 7 has been determined to compensate for the signals of the subcarriers of the received signal. A signal reproduction unit is behind the equalizer unit 8th arranged. This signal reproducing unit reproduces the original transmission data from the result of the output by the equalizer unit 8th determined adjustment.

The subcarrier performance calculation unit 9 is a component for calculating electric subcarrier power from the signal of each subcarrier transmitted through the Fourier transform unit 2 has been determined. The first inverse Fourier transformation unit 10a is a component for generating an electric power base delay profile (first delay profile) from the result of the subcarrier power calculation unit 9 performed calculation. The second inverse Fourier transformation unit 10b is a component for generating an SP base delay profile (a second delay profile) by using the result that the second inverse Fourier transform unit is performed by performing an inverse Fourier transform on the signal passing through the time direction interpolation unit 6 determined line characteristic signals determined.

The delay profile synthesis unit 11 is a component for receiving the electric power base delay profile from the first inverse Fourier transform unit 10a and also for receiving the SP base delay profile from the second inverse Fourier transform unit 10b , The delay profile synthesis unit 11 leaves each value included in the SP base delay profile intact and corresponding to an arrival time having a value equal to or greater than a threshold in the electric power base delay profile and replaces each of other values contained in the SP base delay profile with a minimum value to produce a new delay profile ,

In general, a transmission signal transmitted from a transmitting station is reflected and attenuated before being transmitted by the receiver or transmitting signals are simultaneously transmitted from a plurality of transmitting stations to the receiver, so that a plurality of input waves, which are so-called multi-path signals, reach the receiver. Data showing the arrival times and intensities (D / U ratio) of the input waves contained in the multipath signals are called a delay profile.

In this delay profile, the highest intensity input shaft is called the main shaft, and an input shaft reaching the receiver later than the main shaft is called a delayed wave, and an input shaft reaching the receiver earlier than the main shaft is called an advanced shaft ,

Next, the operation of the digital broadcast receiver will be explained.

First, the sub-carrier power calculation unit squared 9 each of the I-axis (real axis) and q-axis (imaginary number axis) values of the signal (complex signal) in the frequency domain of each subcarrier, which is passed through the Fourier transform unit 2 is determined, and adds the square of the I-axis value and the square of the Q-axis value. The subcarrier power calculating unit then outputs this addition result to the first inverse Fourier transform unit 10a as an I-axis value for an inverse Fourier transform performed by the first inverse Fourier transform unit, and also gives zero to the first inverse Fourier transform unit 10a as a Q-axis value for the inverse Fourier transform.

The first inverse Fourier transformation unit 10a performs an inverse Fourier transform on the inputs and squares each of the inverse Fourier transformed I-axis and Q-axis values thereby and outputs the addition result to the delay profile synthesis unit 11 as an electrical power base delay profile (a first delay profile).

The electric power-base delay profile is characterized in that a main shaft is centered, its time period during which input waves can be detected ranges from zero to Ts / 2, and a delayed wave and an advanced wave appear symmetrical with respect to the main wave. The electrical power base delay profile determined by the first inverse Fourier transform unit may be used after smoothing.

The second inverse Fourier transformation unit 10b performs an inverse Fourier transform on the output (a complex signal) of the time direction interpolation unit 6 and squares each of the output inverse Fourier transformed I-axis and Q-axis values and adds the square of the I-axis value and the square of the Q-axis value. The second inverse Fourier transform unit then outputs the addition result to the delay profile synthesis unit 11 as an SP base delay profile (a second delay profile). The central position of the period during which input waves can be detected in the SP base delay profile is referred to as a demodulation reference point. That is, in the SP base delay profile, input waves can be centered detected within a time period with a time length of ± Ts / 6 and demodulation reference point. The SP base delay profile determined by the second inverse Fourier transform unit may be used after smoothing.

Further, the order in which all the data appears in the electric power base and SP basic delay profiles is referred to as an index, and each index corresponds to an arrival time.

10 FIG. 12 is a flowchart showing an operation of the deceleration profile synthesis unit according to Embodiment 1 and FIG 11 Fig. 12 is an explanatory drawing explaining a process of synthesizing the delay profiles. Referring to 11 the process of generating a new delay profile according to 10 be explained.

The delay profile synthesis unit 11 detects the index of the main wave in the SP base delay profile (step ST1). Since the main wave has the largest value in the delay profile, the delay profile synthesis unit detects the index corresponding to the largest of the values of all data of the SP base delay profile as the index of the main wave.

The delay profile synthesis unit 11 then calculates a main-wave offset equivalent to the difference between the index of the main wave of the SP basic delay profile and the index of the center (demodulation reference point) of the SP basic delay profile (step ST2). α representing the difference between the index of the center (demodulation reference point) of the SP base delay profile represented by a dashed line in FIG 11 (a) is shown, and the index of the main shaft is, the main shaft misalignment. Therefore, the delay profile synthesis unit subtracts 11 the index of the center (demodulation reference point) of the SP base delay profile from the index of the main wave of the SP base delay profile to calculate the subtraction result of the main-wave offset α. As in 11 (b) As shown, the main shaft is securely centered in the electric power base delay profile.

The delay profile synthesis unit 11 then sets each index in the electric power base delay profile (step ST3). At this time, the delay profile synthesis unit offsets each index of the electric power base delay profile by the main wave offset α to change the index of all the data. Thereby, the delay profile synthesis unit causes the index of the main wave of the SP basic delay profile to match that of the main electric power base delay profile wave, as in FIG 11 (c) shown.

The delay profile synthesis unit 11 in step ST3 reads the values contained in the electric power base delay profile in which the indices are offset in units of an index (step ST4) and compares each value read thereby with a predetermined threshold value to determine if the read value is smaller than the threshold value or not (step ST5). At this time, if the read value is equal to or greater than the threshold (if NO in step ST5), the delay profile synthesis unit does not perform any process on the SP basic delay profile data corresponding to the arrival time (index) of this read value, but switches a process of step ST7.

On the other hand, if the read value is smaller than the threshold value (if YES in step ST5), the delay profile synthesis unit replaces 11 the data of the SP basic delay profile corresponding to the arrival time (index) having this read-in value is zero (or a minimum value which is not handled as input shaft data) (step ST6).

There is a case where a delay time in the SP basic delay profile does not uniquely match any delay time in the electric power base delay profile, depending on the number of points in the inverse Fourier transform. In that case, the delay profile synthesis unit selects the value of the delay time (index) closest to the read-in value and replaces this value with zero or the above-mentioned minimum value. Further, if no value corresponding to the delay time exists in the SP base delay profile, the delay profile synthesis unit does not execute a process. This is because, while the delay time range (detection period) is from 0 to Ts / 2 in the electric power base delay profile, the delay time range is that of -Ts / 6 to + Ts / 6 in the SP base delay profile.

Each time the above-mentioned process is performed, the delay profile synthesis unit determines 11 Whether or not the process is to be performed on all indices of the electric power base delay profile (step ST7). If the process in all electric power base delay profile indices is not completed (if NO in step ST7), the delay profile synthesis unit returns to the process of step ST4 and reads in the value corresponding to the next index of the electric power base delay profile and repeats Processes of steps ST4 to ST7.

On the other hand, if the process has been completed on all indices of the electric power-base delay profile (if YES in step ST7), the delay profile synthesis unit gives 11 the SP base delay profile, in which each of the values corresponding to the smaller values than the threshold in the electric power base delay profile is replaced by zero or the minimum value, as a synthesis delay profile in which the advantageous effects of both delay profiles are combined into a so-called composite effect , out.

More specifically, even in a case where an incoming pseudo wave is included in an original SP base delay profile, the receiver removes the incoming pseudowell in the SP base delay profile using the advantage of the electric power base delay profile on which no incoming pseudo waves appear capable of having a delay profile as in 11 (d) shown as a synthetic delay profile and to prevent any incoming pseudo waves from appearing on the delay profiles.

Furthermore, although the distinction between an advanced wave and a delayed wave in the electric power-base delay profile can not be made, the distinction between an advanced wave and a delayed wave in the synthesized delay profile can be made by using the SP base delay profile in which the distinction between an advanced wave and a delayed wave can be made as in 11 (d) shown.

Further, when there are a plurality of incoming waves, although the electric power-base delay profile has the disadvantage that cross-modulation occurs therein and an incoming wave that does not originally exist, appears in it, no incoming wave that does not originally exist appears in the synthetic delay profile. As mentioned above, the digital broadcasting receiver according to Embodiment 1 can correctly determine a delay profile as compared with conventional technologies.

As mentioned above, the digital broadcasting receiver according to Embodiment 1 includes the Fourier transform unit 2 for performing a Fourier transform on the received OFDM signal on a per-transmission unit basis; the sub-carrier power calculation unit 9 for calculating sub-carrier power data from data representing the Fourier transform unit 2 by performing the Fourier transform on the received OFDM signal; the first inverse Fourier transform unit 10a performing an inverse Fourier transform on the subcarrier power data to produce a power base electrical delay profile; the pilot signal extraction unit 3 for extracting a pilot signal from the data representing the Fourier transform unit 2 by performing the Fourier transform on the received OFDM signal; the divider unit 5 for dividing the pilot signal by a known value to calculate transmission line characteristic data for the pilot signal provided on a per transmission unit basis; the time direction interpolation unit 6 for interpolating intermediate data in a time direction between the transmission line characteristic data, which are all calculated for the pilot signal provided on a per transmission unit basis; the second inverse Fourier transform unit 10b for performing an inverse Fourier transform on the transmission line characteristic data into which the intermediate data is interpolated in time direction to generate an SP base delay profile; and the delay profile synthesis unit 11 for offsetting the detection time of each incoming wave of the electric power base delay profile in such a way that the arrival time of the main wave of the electric power base delay profile matches a main wave of the SP base delay profile and also leaves intact any value that is present in the SP base Delay profile, and corresponds to an arrival time corresponding to a value equal to or greater than a predetermined threshold in the electric power base delay profile in which the detection time of each incoming wave is offset, and to replace each included in the SP base delay profile and an arrival time a value less than the threshold corresponding value by a value that is not handled as an incoming wave (zero or a minimum value that is not handled as an incoming wave), the SP base delay profile as a delay profile of the received OFDM -Signal s spend.

Thus, by removing the incoming pseudo-wave in the SP base delay profile by using the electric power base delay profile, the digital broadcast receiver can determine a delay profile that provides a beneficial effect in which the beneficial effects of both the electric power base delay profile and the SP Base delay profiles are combined. Further, even in an environment in which a moving object in which the digital broadcast receiver is mounted moves at high speed, the digital broadcast receiver detects a delay profile with correct arrival times and correct electric power.

Embodiment 2

A digital broadcasting receiver according to this Embodiment 2 has the same fundamental structure as that according to the above-mentioned Embodiment 1, while a method for generating a synthetic delay profile according to this Embodiment 2 differs from that according to Embodiment 1.

While the structure of the digital broadcasting receiver according to Embodiment 2 is described with reference to the embodiment 1 mentioned above 9 will be explained, details of a process for generating a synthesized delay profile according to Embodiment 2 will be explained.

12 FIG. 10 is a flowchart showing an operation flow of a deceleration profile synthesis unit according to Embodiment 2 of the present invention. FIG. The process of generating a new delay profile will be explained according to this flowchart.

The delay profile synthesis unit 11 detects the index of a main wave of an SP base delay profile (step ST1a). Since the main wave has the largest value in the delay profile, the delay profile synthesis unit detects the index corresponding to the largest of the values of all the data from the SP basic delay profile as the index of the main wave.

The delay profile synthesis unit 11 then calculates a main-wave offset equivalent to the difference between the index of the main wave of the SP basic delay profile and the index of the center (demodulation reference point) of the SP basic delay profile (step ST2a). At this point, the delay profile subtracts synthesis unit 11 the index of the center (demodulation reference point) of the SP base delay profile from the index of the main wave of the SP base delay profile to calculate the subtraction result as the main-wave displacement α.

Then, the delay profile synthesis unit displaces 11 every index in the electric power base delay profile (step ST3a). At this time, the delay profile synthesis unit offsets each index in an electric power base delay profile by the main shaft offset α to change the index of all data to cause the index of the main wave of the SP base delay profile to that of the main shaft of the electric power base delay profile to fit.

The delay profile synthesis unit 11 in step ST3a reads the values included in the electric power base delay profile in which the indexes are offset in units of an index (step ST4a) and multiplies each value thus read by the value contained in the SP base delay profile according to the arrival time (index) of that read value (Step ST5a).

There is a case where a delay time in the SP basic delay profile does not uniquely match any delay time in the electric power base delay profile, depending on the number of points in the inverse Fourier transform. In this case, the delay profile synthesis unit selects the value of the delay time (index) closest to the read-in value and multiplies that value by the value included in the SP base delay profile corresponding to the time delay having this read-in value.

Furthermore, if there is no value corresponding to the delay time in the SP basic delay profile, the delay profile synthesizing unit does not execute a process. This is because, while the delay time range (detection period) is from zero to Ts / 2 in the electric power base delay profile, the delay time range is that of -Ts / 6 to + Ts / 6 in the SP base delay profile.

Each time the above-mentioned process is performed, the delay profile synthesis unit determines 11 Whether or not the process is to be performed on all indices of the electric power base delay profile (step ST6a). If the process is not completed in all indices of the electric power base delay profile (if NO in step ST6a), the delay profile synthesis unit returns to the process of step ST4a and reads in the value corresponding to the next index of the electric power base delay profile and repeats Processes of steps ST4a to ST6a.

In contrast, when the process in all indices of the electric power base delay profile has been completed (if YES in step ST6a), the delay profile synthesis unit gives 11 the result of multiplying the value of each index of the electrical power base delay profile and that of the corresponding index of the SP base delay profile as a delay profile of the received OFDM signal.

Because the digital broadcast receiver prevents any incoming pseudo waves from appearing in the electric power base delay profile by generating a delay profile in this way, even if an incoming pseudo wave is included in the SP base delay profile, the digital broadcast receiver can adjust the level of the incoming pseudo wave through the multiplication process to reduce.

Furthermore, although the distinction between an advanced wave and a delayed wave in the electric power-base delay profile can not be made, the discrimination between an advanced wave and a delayed wave can be made by synthesizing the electric power base delay profile and the SP base delay profile.

Furthermore, if there are a plurality of incoming waves, although the electric power base delay profile has the disadvantage that cross-modulation occurs therein and an incoming wave that does not originally exist appears therein, synthesizing the electric power-base delay profile and the SP- Base delay profiles via the modification process reduce the level of the incoming wave because the incoming wave does not exist in the SP base delay profile.

As mentioned above, the digital broadcasting receiver according to Embodiment 2 can correctly determine a delay profile as compared with conventional technologies. Furthermore, the digital broadcasting receiver does not have to compare each value included in the electric power-base delay profile with the predetermined threshold, and to adjust the threshold, the structure of the digital broadcasting receiver can be simplified as compared with that according to the above-mentioned Embodiment 1.

As mentioned above, the digital broadcasting receiver according to Embodiment 2 includes: the Fourier transform unit 2 for performing a Fourier transform on the received OFDM signal on a per-transmission unit basis; the sub-carrier power calculation unit 9 for calculating sub-carrier power data from data representing the Fourier transform unit 2 by performing the Fourier transform on the received OFDM signal; the first inverse Fourier transform unit 10a performing an inverse Fourier transform on the subcarrier power data to produce a power base electrical delay profile; the pilot signal extraction unit 3 for extracting a pilot signal from the data representing the Fourier transform unit 2 by performing the Fourier transform on the received OFDM signal; the divider unit 5 for dividing the extracted pilot signal by a known value to calculate transmission line characteristic data for the pilot signal provided on a per transmission unit basis; the time direction interpolation unit 6 for interpolating intermediate data in a time direction between the transmission line characteristic data, which are all calculated for the pilot signal provided on a per transmission unit basis; the second inverse Fourier transform unit 10b for performing an inverse Fourier transform on the transmission line characteristic data into which the intermediate data is interpolated in time direction to generate an SP base delay profile; and the delay profile synthesis unit 11 for offsetting the detection time of each incoming wave of the electric power base delay profile in such a manner that the arrival time of the main wave of the electric power base delay profile matches that of the main wave of the SP base delay profile and multiplying values of arrival times of the electric power base delay profile, wherein the detection timing of each incoming wave is offset by respective values of respective arrival times of the SP base delay profile, respectively, to output a result of the multiplication as a delay profile of the received OFDM signal.

By thus synthesizing the values of the electric power base delay profile and those of the SP base delay profile, the digital broadcast receiver may cause the error signal contained in the electric power base delay profile and the error signal included in the SP base delay profile to cancel each other and detect a delay profile with correct arrival times. even if a moving object in which the digital broadcast receiver is mounted moves at high speed. Furthermore, because the digital broadcasting receiver does not need to have thresholds, the digital broadcasting receiver is simplified in structure as compared with that according to the above-mentioned Embodiment 1.

Embodiment 3

A digital broadcasting receiver according to this Embodiment 3 has the same fundamental structure as that according to the above-mentioned Embodiment 1, while a method for generating a synthetic delay profile according to this Embodiment 3 is different from that according to Embodiment 1.

While the structure of the digital broadcasting receiver according to Embodiment 3 is described with reference to the embodiment 1 mentioned above 9 will be explained, details of a process for generating a synthesized delay profile according to Embodiment 3 will be explained.

13 FIG. 4 is an explanatory drawing explaining the process of synthesizing delay profiles according to Embodiment 3 of the present invention. FIG. In the case of an SP base delay profile as described with reference to 7 In the above-mentioned embodiment 1, when the arrival time of an incoming wave does not fall within a period of ± Ts / 6 with respect to a demodulation reference point, an advanced wave is aliased to a delayed wave and a delayed wave becomes an advanced one Wave folded (aliased), and they appear in the delay profile. 13 (a) Fig. 10 shows a case where an advanced wave arriving earlier than the period of -Ts / 6 with respect to the demodulation reference point is aliased and then appears as a delayed wave in the delay profile.

In the case of an electric power base delay profile, although the time period during which the incoming wave can be detected has a length of up to Ts / 2, as in FIG 13 (c) On the other hand, only the relative time difference between a delayed wave and an advanced wave with respect to the main wave is determined. Therefore, the discrimination between an advanced wave and a delayed wave at incoming waves detected within the period of ± Ts / 2 with respect to the center (main wave) of the electric power base delay profile can not be made.

To solve this problem, the delay profile synthesis unit inserts 11 According to Embodiment 3, a copy of the contents of a part of the SP base delay profile within the detection period of ± Ts / 6 centered on the demodulation reference point, before and after the detection period of the original SP base delay profile, as shown in FIG 13 (b) to produce a delay profile (a third delay profile).

Because this delay profile matches part of the electric power base delay profile within the time period of ± Ts / 2 with respect to its center, the delay profile synthesis unit can generate a delay profile of the received OFDM signal using the same method as that described in the above Embodiment 1 or 2 is used.

More specifically, the delay profile synthesis unit performs a process of offsetting the electric power base delay profile part within the time period of ± Ts / 2 with respect to its center (causing each index of the main electric power base delay profile wave to those of the main wave of the SP Base delay profile), reads in the values contained in the electric power base delay profile in which the indices are offset, in units of an index, to compare each value read thereby with a predetermined threshold, and replaces each in the above-mentioned SP Base delay profile value corresponding to the index having an input value smaller than the threshold value by zero or a minimum value to generate a delay profile of the received OFDM signal as that according to the above-mentioned Embodiment 1.

Alternatively, the delay profile synthesis unit performs a process of offsetting the part of the electric power base delay profile within the period of ± Ts / 2 with respect to its center (causing each index of the main shaft of the electric power base delay profile to those of the main shaft the SP base delay profile), reads in the values contained in the electrical power base delay profile in which the indices are offset, in units of an index, and multiplies each value read thereby with the value contained in the SP base delay profile which corresponds to the time of arrival ( Index) corresponds to this read-in value to generate a delay profile of the received OFDM signal, as that according to the above-mentioned Embodiment 2.

Thus, by synthesizing the SP base delay profile and the electric power base delay profile in such a manner that the detection period of the SP base delay profile matches that of the electric power base delay profile, the digital broadcast receiver can correctly detect an incoming wave that is aliased and appears in the SP base delay profile, and whose arrival time does not fall within the period of ± Ts / 6. Another advantage is provided to be able to expand the maximum delay time in which incoming waves can be detected to ± Ts / 2.

As mentioned above, in the digital broadcast receiver according to this embodiment 3, the delay profile synthesis unit generates 11 a delay profile of the received OFDM signal using both the delay profile, in which the contents of a part of the SP base delay profile resulting from the second inverse Fourier transform 10BM within the detection period during which incoming waves are detected until before and after the above-mentioned detection period and an electric power base delay profile within the period of ± Ts / 2 with respect to its center.

In this way, the digital broadcast receiver provides the same advantage as that provided by the above-mentioned embodiment 1 or 2, and can also triple expand the maximum delay time in which incoming wave can be detected.

Embodiment 4

14 Fig. 10 is a block diagram showing the structure of a digital broadcasting receiver according to Embodiment 4 of the present invention. In the structure according to any one of Embodiments 1 to 3, the two inverse Fourier transform units which are the first inverse Fourier transform unit 10a and the second inverse Fourier transform unit 10b include, included. In contrast, the digital radio receiver 1b according to embodiment 4 only with an inverse Fourier transformation unit 10 provided, as in 14 shown. More specifically, a signal selection unit switches 12 between an output of a sub-carrier power calculation unit 9 and an output of a time direction interpolation unit 6 to get one of the outputs to the inverse Fourier transform unit 10 and the single inverse Fourier transform unit 10 performs the generation of both an electrical power base delay profile and an SP base delay profile. Furthermore, a storage unit 13 a storage unit for storing the data by the inverse Fourier transform unit 10 generated delay profiles and each in The delay profile stored in the memory unit is passed through a delay profile synthesis unit 11 read in as required. In 14 become the same components as those in 9 are shown with the same reference numerals, and the explanation of the components will be omitted below.

Next, the operation of the digital broadcasting receiver will be explained.

The signal selection unit 12 selects each of the subcarrier power calculation unit outputs 9 and the time direction interpolation unit 6 which are obtained from the identical signal received by the receiver, and both of them are applied to the inverse Fourier transform unit 10 one.

The inverse Fourier transformation unit 10 performs an inverse Fourier transform on each of the output signals of the sub-carrier power calculation unit 9 and the time direction interpolation unit 6 through it via the signal selection unit 12 and squares each of the I-axis and Q-axis values of the result of the inverse Fourier transform of each output signal and adds the square of the I-axis value and that of the Q-axis value. The inverse Fourier transform unit then stores the addition results in the memory unit 13 as an electric power base delay profile and an SP base delay profile.

At this time, the inverse Fourier transform unit 10 generate a profile in which a copy of the content of a part of the SP base delay profile within a detection period during which incoming waves are detected is inserted in time sequence before and after the detection period, as shown in Embodiment 3, and stores the profile in the memory unit 13 ,

The delay profile synthesis unit 11 generates a delay profile of the received OFDM signal using the electrical power base delay profile and the SP base delay profile stored in the memory unit 13 are stored by the same method as that shown in any one of Embodiments 1 to 3.

As mentioned above, the digital broadcasting receiver according to Embodiment 4 includes: a Fourier transform unit 2 for performing a Fourier transform on the received OFDM signal on a per-transmission unit basis; the sub-carrier power calculation unit 9 for calculating sub-carrier power data from data representing the Fourier transform unit 2 by performing the Fourier transform on the received OFDM signal; a pilot signal extraction unit 3 for extracting a pilot signal from the data representing the Fourier transform unit 2 by performing the Fourier transform on the received OFDM signal; a divider unit 5 for dividing the pilot signal by a known value to calculate transmission line characteristic data for the pilot signal provided on a per transmission unit basis; the time direction interpolation unit 6 for interpolating intermediate data in a time direction between the transmission line characteristic data, which are all calculated for the pilot signal provided on a per transmission unit basis; the signal selection unit 12 for switching between the output data from the sub-carrier power calculating unit 9 and those from the time direction interpolation unit 6 to select one of them; the inverse Fourier transform unit 10 for performing an inverse Fourier transform on the signal selection unit 12 selected output data; and the storage unit 13 for storing both the electrical power base delay profile, the inverse Fourier transform unit 10 by performing the inverse Fourier transform on the output data from the sub-carrier power calculating unit 9 as well as the SP base delay profile, which is the inverse Fourier transform unit 10 by performing the inverse Fourier transform on the output data from the time direction interpolation unit 6 generated, and the delay profile synthesis unit 11 generates and outputs a delay profile of the received OFDM signal using both the electrical power base delay profile and the SP base delay profile which the delay profile synthesis unit retrieves from the memory unit 13 reads. Because the digital broadcasting receiver is constructed as above, the number of inverse Fourier transforming units included in the digital broadcasting receiver can be reduced from two to one, and therefore the circuit of the digital broadcasting receiver can be reduced in size.

Embodiment 5

15 Fig. 10 is a block diagram showing the structure of a digital broadcasting receiver according to Embodiment 5 of the present invention. The digital radio receiver 1C according to Embodiment 5 includes a Fourier transform time generation unit 14 in addition to the structural components according to the above-mentioned embodiment 4. The Fourier transform time generation unit 14 is a component for generating an optimal Fourier transform time (a time at which the digital broadcast receiver starts a Fourier transform) according to an output (a synthetic delay profile) of a delay profile synthesis unit 11 , The generated Fourier transform time is from the Fourier transform time generation unit 14 a Fourier transform unit 2 communicated. For example, if an incoming wave having an arrival time that does not fall within a guard interval appears in a delay profile, the Fourier transform time generation unit changes 14 the Fourier transform time in such a way that the arrival time falls within the guard interval. Accordingly, the digital broadcast receiver can improve its receiving ability. The delay profile synthesis unit 11 generates a synthetic delay profile according to the same method as that shown in any of the above-mentioned Embodiments 1 to 3.

Further, according to Embodiment 5, a time direction interpolation unit determines 6 and a frequency direction interpolation unit 7 their corresponding optimal interpolation coefficients from the output (synthetic delay profile) of the delay profile synthesis unit 11 , For example, if an incoming wave falling within a band exceeding that of the interpolation coefficient appears in the delay profile, each of the interpolation units changes the interpolation coefficient in such a manner that the incoming wave falls within the band of the interpolation coefficient.

The digital broadcasting receiver according to Embodiment 5 can control the Fourier transform time with the above-mentioned Fourier transform time generation unit 14 , the control of the interpolation coefficient with the time direction interpolation unit 6 and / or the control of the interpolation coefficient with the frequency direction interpolation unit 7 or may combine some or all of these control operations.

As mentioned above, because the digital broadcasting receiver according to Embodiment 5, the Fourier transform time generation unit 14 for determining the timing of starting the Fourier transform (start time) from that by the delay profile synthesis unit 11 generated synthetic delay profile, the digital broadcast receiver can correctly determine the time of starting the Fourier transform, using the correct delay profile, by the delay profile synthesis unit 11 is generated and contains no error signals.

Furthermore, because the time direction interpolation unit 6 or the frequency direction interpolation unit 7 their interpolation coefficients from that through the delay profile synthesis unit 11 determined synthetic delay profile, the digital broadcast receiver can determine an optimal interpolation coefficient using the correct delay profile, the delay profile synthesis unit 11 is generated and contains no error signals.

By performing the control operation using the delay profile synthesis result without error in this manner, the digital broadcast receiver can avoid erroneous control even when a moving object in which the receiver is mounted moves at a high speed and even in an environment, in which an incoming wave with a long delay time reaches the receiver, whereby it is able to improve its reception capabilities.

Further, although in Embodiment 5, the example in which the digital broadcasting receiver is the Fourier transform time generation unit 14 In addition to the structural components according to Embodiment 4, the concept of Embodiment 5 may be applied to the digital broadcast receiver according to any one of Embodiments 1 to 3, and the digital broadcast receiver may be constructed in such a manner as to control the Fourier broadcasting. Transformation time with the Fourier transformation time generation unit 14 , the control of the interpolation coefficient with the time direction interpolation unit 6 and / or the control of the interpolation coefficient with the frequency direction interpolation unit 7 or may perform a combination of some or all of the control operations.

INDUSTRIAL APPLICABILITY

Because the digital broadcasting receiver according to the present invention can provide a delay profile containing no errors and can perform correct reception without causing erroneous control even in an environment where a moving object in which the digital broadcasting receiver itself is mounted, is moving at a high speed, and even if an incoming wave having an arrival time that does not fall within a period in which incoming waves can be detected appears in the SP base delay profile, the digital broadcasting receiver according to the present invention is for use as a digital vehicle radio receiver suitable.

Claims (24)

A digital broadcast receiver for receiving an orthogonal frequency divider multiplex signal, the digital broadcast receiver comprising: a Fourier transform unit ( 2 ) for performing a Fourier transform on the received orthogonal frequency division multiplexed signal on a per-transmission unit basis; a sub-carrier power calculation unit ( 9 ) for calculating sub-carrier power data from data representing the Fourier transform unit ( 2 ) is determined by performing the Fourier transform on the received orthogonal frequency divider multiplex signal; a first inverse Fourier transformation unit ( 10a ) for performing an inverse Fourier transformation on the subcarrier power calculation unit ( 9 ) calculate sub-carrier power data to produce a first deceleration profile; a pilot signal extraction unit for extracting a pilot signal from the data which the Fourier transformation unit ( 2 ) is determined by performing the Fourier transform on the received orthogonal frequency division multiplexed signal; a divider unit ( 5 ) for sharing by the pilot signal extraction unit ( 3 ) extracted pilot signal by a known value to calculate transmission line characteristic data for the pilot signal provided on a per transmission unit basis; a time direction interpolation unit ( 6 ) for interpolating intermediate data in a time direction between the transmission line characteristic data, all of which for the pilot signal provided on a per transmission unit basis by the divider unit (13). 5 ) be calculated; a second inverse Fourier transformation unit ( 10b ) for performing an inverse Fourier transform on the transmission line characteristic data into which the intermediate data in the time direction by the time direction interpolation unit (FIG. 6 ) are interpolated to produce a second delay profile; and a delay profile synthesis unit ( 11 ) for offsetting a detection time of each incoming wave by the first inverse Fourier transform unit ( 10a ) in such a way that an arrival time of a main wave of the first delay profile to a main wave of the second inverse Fourier transformation unit ( 10b ) and also leaves intact any value contained in the second delay profile corresponding to an arrival time equal to or greater than a predetermined threshold in the first delay profile in which the detection time of each incoming wave is offset; and for replacing each value included in the second delay profile and an arrival time with a value less than the threshold value by a value that is not handled as an incoming wave to output the second delay profile as a delay profile of the received orthogonal frequency divisional multiplex signal. The digital broadcast receiver of claim 1, wherein the digital broadcast receiver generates a third delay profile in which a copy of the content of a portion of the second delay profile within a detection period during which incoming waves are selected, the second delay profile being determined by the second inverse Fourier transform unit. 10b ) is inserted in front of and behind a part of the second delay profile within the detection period, and the delay profile synthesis unit ( 11 ) the detection time of each incoming wave of the first delay profile generated by the first inverse Fourier transformation unit ( 10a ) is offset in such a manner that the arrival time of the main wave of the first delay profile matches with that of a main wave of the third delay profile, instead of the second delay profile, and also leaves each arrival time included in the third delay profile equal to or greater than a value the predetermined threshold in the first delay profile, in which the detection time of each incoming wave is offset, corresponding value intact and replaces each value included in the third delay profile and an arrival time with a value smaller than the threshold by the value that is not handled as an incoming wave to output the third delay profile as the delay profile of the received orthogonal frequency divider multiplex signal. A digital broadcasting receiver according to claim 1, wherein said digital broadcasting receiver comprises a Fourier transform time generation unit ( 14 ) for determining a time at which the Fourier transformation unit ( 2 ) Performs the Fourier transform according to the content of the delay profile synthesis unit ( 11 ) generated delay profile includes. A digital broadcasting receiver according to claim 1, wherein the time direction interpolation unit ( 6 ) an interpolation coefficient in the interpolation in the time direction of the intermediate data between the transmission line characteristic data in accordance with the content of the delay profile synthesis unit ( 11 ) determined delay profile. A digital broadcasting receiver according to claim 1, wherein the digital broadcasting receiver is a Frequency direction interpolation unit ( 7 ) for interpolating intermediate data in a frequency direction between the transmission line characteristic data into which the intermediate data in the time direction by the time direction interpolation unit (14) 6 ), and the frequency direction interpolation unit ( 7 ) an interpolation coefficient in the interpolation in the frequency direction of the intermediate data between the transmission line characteristic data in accordance with the content of the delay profile synthesis unit ( 11 ) determined delay profile. A digital broadcast receiver for receiving an orthogonal frequency divider multiplex signal, the digital broadcast receiver comprising: a Fourier transform unit ( 2 ) for performing a Fourier transform on the received orthogonal frequency division multiplexed signal on a per-transmission unit basis; a sub-carrier power calculation unit ( 9 ) for calculating sub-carrier power data from data representing the Fourier transform unit ( 2 ) is determined by performing the Fourier transform on the received orthogonal frequency divider multiplex signal; a first inverse Fourier transformation unit ( 10a ) for performing an inverse Fourier transformation on the subcarrier power calculation unit ( 9 ) calculate sub-carrier power data to produce a first deceleration profile; a pilot signal extraction unit ( 3 ) for extracting a pilot signal from the data which the Fourier transformation unit ( 2 ) is determined by performing the Fourier transform on the received orthogonal frequency division multiplexed signal; a divider unit ( 5 ) for sharing by the pilot signal extraction unit ( 3 ) extracted pilot signal by a known value to calculate transmission line characteristic data for the pilot signal provided on a per transmission unit basis; a time direction interpolation unit ( 6 ) for interpolating intermediate data in a time direction between the transmission line characteristic data, all of which for the pilot signal provided on a per transmission unit basis by the divider unit (13). 5 ) be calculated; a second inverse Fourier transformation unit ( 10b ) for performing an inverse Fourier transform on the transmission line characteristic data into which the intermediate data in the time direction by the time direction interpolation unit (FIG. 6 ) are interpolated to produce a second delay profile; and a delay profile synthesis unit ( 11 ) for offsetting a detection time of each incoming wave by the first inverse Fourier transform unit ( 10a ) in such a way that an arrival time of a main wave of the first delay profile to a main wave of the second inverse Fourier transformation unit ( 10b ) and multiplying values of arrival times of the first delay profile by respectively offsetting the detection time of each incoming wave by values of respective arrival times of the second delay profile to output a result of the multiplication as a delay profile of the received orthogonal frequency divider multiplex signal , A digital broadcast receiver according to claim 6, wherein the digital broadcast receiver generates a third delay profile in which a copy of the content of a portion of the second delay profile within a detection period during which incoming waves are selected, the second delay profile being determined by the second inverse Fourier transform unit. 10b ) is inserted in front of and behind a part of the second delay profile within the detection period, and the delay profile synthesis unit ( 11 ) the detection time of each incoming wave of the first delay profile generated by the first inverse Fourier transformation unit ( 10a ) is offset in such a manner that the arrival time of the main wave of the first delay profile matches that of a main wave of the third delay profile, instead of the second delay profile, and also the values of arrival times of the first delay profile in which the detection time of each incoming wave is offset is respectively multiplied by values of respective arrival times of the third delay profile to output a result of the multiplication as the delay profile of the received orthogonal frequency divider multiplex signal. A digital broadcasting receiver according to claim 6, wherein the digital broadcasting receiver comprises a Fourier transform time generation unit ( 14 ) for determining a time at which the Fourier transformation unit ( 2 ) Performs the Fourier transform according to the content of the delay profile synthesis unit ( 11 ) generated delay profile includes. A digital broadcasting receiver according to claim 6, wherein the time direction interpolation unit ( 6 ) an interpolation coefficient in the interpolation in the time direction of the intermediate data between the transmission line characteristic data in accordance with the content of the delay profile synthesis unit ( 11 ) determined delay profile. A digital broadcast receiver according to claim 6, wherein said digital broadcast receiver is a frequency direction interpolation unit ( 7 ) for interpolating intermediate data in a frequency direction between the transmission line characteristic data into which the intermediate data in the time direction by the time direction interpolation unit (14) 6 ), and the frequency direction interpolation unit ( 7 ) an interpolation coefficient in the interpolation in the frequency direction of the intermediate data between the transmission line characteristic data in accordance with the content of the delay profile synthesis unit ( 11 ) determined delay profile. A digital broadcast receiver according to claim 1, further comprising: a signal selection unit ( 12 ) for providing the output data of the sub-carrier power calculating unit ( 9 ) and the output data of the time direction interpolation unit ( 6 ) the first and second Fourier transformation units ( 10a . 10b ); and a storage unit ( 13 ) for storing both the first delay profile and that of the first and second inverse Fourier transformation units ( 10a . 10b ) detected second delay profile, wherein the delay profile synthesis unit ( 11 ) is adapted to output the delay profile of the received orthogonal frequency division multiplexed signal by the use of the first delay profile and the second delay profile, both of which are from the memory unit ( 13 ), and wherein the first and second inverse Fourier transformation units ( 10a . 10b ) by a common single transformation unit ( 10 ) are executed. The digital broadcast receiver of claim 11, wherein the digital broadcast receiver generates a third delay profile in which a copy of the content of a portion of the second delay profile within a detection period during which incoming waves are selected, the second delay profile being determined by the inverse Fourier transform unit. 10 ) is inserted in front of and behind a part of the second delay profile within the detection period, and the delay profile synthesis unit ( 11 ) offset the detection time of each incoming wave of the first delay profile in such a way that the arrival time of the main wave of the first delay profile matches that of a main wave of the third delay profile, instead of the second delay profile, and also includes each arrival time included in the third delay profile a value equal to or greater than the predetermined threshold in the first delay profile in which the detection time of each incoming wave is offset remains intact and replaces each value included in the third delay profile and corresponding to an arrival time smaller than the threshold by the value that is not is handled as an incoming wave to output the third delay profile as the delay profile of the received orthogonal frequency divider multiplex signal. A digital broadcasting receiver according to claim 11, wherein the digital broadcasting receiver comprises a Fourier transform time generation unit ( 14 ) for determining a time at which the Fourier transformation unit ( 2 ) Performs the Fourier transform according to the content of the delay profile synthesis unit ( 11 ) generated delay profile includes. A digital broadcasting receiver according to claim 11, wherein the time direction interpolation unit ( 6 ) an interpolation coefficient in the interpolation in the time direction of the intermediate data between the transmission line characteristic data in accordance with the content of the delay profile synthesis unit ( 11 ) determined delay profile. The digital broadcasting receiver according to claim 11, wherein the digital broadcasting receiver is a frequency direction interpolation unit ( 7 ) for interpolating intermediate data in a frequency direction between the transmission line characteristic data into which the intermediate data in the time direction by the time direction interpolation unit (14) 6 ), and the frequency direction interpolation unit ( 7 ) an interpolation coefficient in the interpolation in the frequency direction of the intermediate data between the transmission line characteristic data in accordance with the content of the delay profile synthesis unit ( 11 ) determined delay profile. A digital broadcast receiver according to claim 6, further comprising: a signal selection unit ( 12 ) for providing the output data of the sub-carrier power calculating unit ( 9 ) and the output data of the time direction interpolation unit ( 6 ) the first and second Fourier transformation units ( 10a . 10b ); and a storage unit ( 13 ) for storing both the first delay profile and that of the first and second inverse Fourier transformation units ( 10a . 10b ) detected second delay profile, wherein the delay profile synthesis unit ( 11 ) is adapted to output the delay profile of the received orthogonal frequency division multiplexed signal by the use of the first delay profile and the second Delay profiles, both of which are from the memory unit ( 13 ), and wherein the first and second inverse Fourier transformation units ( 10a . 10b ) by a common single transformation unit ( 10 ) are executed. The digital broadcast receiver of claim 16, wherein the digital broadcast receiver generates a third delay profile in which a copy of the content of a portion of the second delay profile is detected within a detection period during which incoming waves are selected, the second delay profile being determined by the inverse Fourier transform unit. 10 ) is inserted in front of and behind the part of the second delay profile within the detection period, and the delay profile synthesis unit ( 11 ) offset the detection time of each incoming wave of the first delay profile in such a way that the arrival time of the main wave of the first delay profile matches that of a main wave of the third delay profile, instead of the second delay profile, and also the values of the arrival times of the first delay profile in which the Detection time of each incoming wave is multiplied by values of respective arrival times of the third delay profile to output a result of the multiplication as the delay profile of the received orthogonal frequency divider multiplex signal. The digital broadcasting receiver according to claim 16, wherein the digital broadcasting receiver includes a Fourier transform time generation unit for determining a time at which the Fourier transform unit starts performing the Fourier transform according to the content of the delay profile generated by the delay profile synthesis unit. The digital broadcasting receiver according to claim 16, wherein the time direction interpolating unit determines an interpolation coefficient in the interpolation in the time direction of the intermediate data between the transmission line characteristic data according to the content of the delay profile generated by the delay profile synthesizing unit. The digital broadcasting receiver according to claim 16, wherein the digital broadcasting receiver includes a frequency direction interpolating unit for interpolating intermediate data in a frequency direction between the transmission line characteristic data in which the intermediate data is interpolated by the time direction interpolation unit in the time direction, and the frequency direction interpolating unit has an interpolation coefficient in the interpolation in the frequency direction of the intermediate data between the transmission line characteristic data in accordance with the content of the delay profile generated by the delay profile synthesis unit. A delay profile generation method for generating a delay profile for a reception signal of a digital broadcasting receiver for receiving an orthogonal frequency division multiplexed signal, the method comprising the steps of: Performing an inverse Fourier transform on subcarrier performance data calculated from data obtained by performing a Fourier transform on a received orthogonal frequency divider multiplexed signal on a per unit of transmission basis to produce a first delay profile; Interpolating intermediate data in a time direction between transmission line characteristic data for pilot signals, all provided on a per transmission unit basis, wherein all transmission line characteristic data are obtained by dividing one of the data obtained by performing the Fourier transform on the received orthogonal frequency divisional multiplex signal , extracted pilot signal on a per transmission unit basis by a known value and performing an inverse Fourier transform on the transmission line characteristic data in which the intermediate data is interpolated in the time direction are determined to generate a second delay profile; Offsetting a detection time of each incoming wave of the first delay profile in such a manner that an arrival time of a main wave of the first delay profile matches that of a main wave of the second delay profile; and leaving intact each value contained in the second delay profile and an arrival time having a value equal to or greater than a predetermined threshold in the first delay profile in which the detection time of each incoming wave is offset, and replacing each in the second delay profile and one Arrival time having a value smaller than the threshold corresponding value by a value that is not handled as an incoming wave to output the second delay profile as a delay profile of the received orthogonal frequency divider multiplex signal. A delay profile generation method for generating a delay profile for a reception signal of a digital broadcasting receiver for receiving an orthogonal frequency divisional multiplex signal, the method comprising the steps of: performing an inverse Fourier transform on subcarrier performance data calculated from data obtained by performing a Fourier Transform on a received orthogonal frequency divider multiplex signal on a per transmission unit basis to generate a first delay profile; Interpolating intermediate data in a time direction between transmission line characteristic data for pilot signals, all provided on a per transmission unit basis, wherein all transmission line characteristic data are obtained by dividing one of the data obtained by performing the Fourier transform on the received orthogonal frequency divisional multiplex signal , extracted pilot signal on a per transmission unit basis by a known value and performing an inverse Fourier transform on the transmission line characteristic data in which the intermediate data is interpolated in the time direction are determined to generate a second delay profile; Offsetting a detection time of each incoming wave of the first delay profile generated by the first inverse Fourier transformation unit ( 10a ) in such a manner that an arrival time of a main wave of the first delay profile matches that of a main wave of a third delay profile in which a copy of contents of a part of the second delay profile is detected within a detection period during which incoming waves are detected is inserted behind the part of the second delay profile within the detection period; and leaving intact each value included in the third delay profile and an arrival time having a value equal to or greater than a predetermined threshold in the first delay profile in which the detection time of each incoming wave is offset, and replacing each in the third delay profile and one Arrival time having a value smaller than the threshold corresponding value by a value that is not handled as an incoming wave to output the second delay profile as a delay profile of the received orthogonal frequency divider multiplex signal. A delay profile generation method for generating a delay profile for a reception signal of a digital broadcasting receiver for receiving an orthogonal frequency divisional multiplex signal, the method comprising the steps of: performing an inverse Fourier transform on subcarrier performance data calculated from data obtained by performing a Fourier Transform on a received orthogonal frequency divider multiplex signal on a per transmission unit basis to generate a first delay profile; Interpolating intermediate data in a time direction between transmission line characteristic data for pilot signals, all provided on a per transmission unit basis, wherein all transmission line characteristic data are obtained by dividing one of the data obtained by performing the Fourier transform on the received orthogonal frequency divisional multiplex signal , extracted pilot signal on a per transmission unit basis by a known value and performing an inverse Fourier transform on the transmission line characteristic data in which the intermediate data is interpolated in the time direction are determined to generate a second delay profile; Offsetting a detection time of each incoming wave of the first delay profile in such a manner that an arrival time of a main wave of the first delay profile matches that of a main wave of the second delay profile; and multiplying values of arrival times of the first delay profile in which the detection time of each incoming wave is offset with values of corresponding arrival times of the second delay profile to output a result of the multiplication as a delay profile of the received orthogonal frequency divider multiplex signal. A delay profile generation method for generating a delay profile for a reception signal of a digital broadcasting receiver for receiving an orthogonal frequency division multiplexed signal, the method comprising the steps of: Performing an inverse Fourier transform on subcarrier performance data calculated from data obtained by performing a Fourier transform on a received orthogonal frequency divider multiplexed signal on a per unit of transmission basis to produce a first delay profile; Interpolating intermediate data in a time direction between transmission line characteristic data for pilot signals, all provided on a per transmission unit basis, wherein all transmission line characteristic data are obtained by dividing one of the data obtained by performing the Fourier transform on the received orthogonal frequency divisional multiplex signal , extracted pilot signal on a per transmission unit basis by a known value and performing an inverse Fourier transform on the transmission line characteristic data in which the intermediate data is interpolated in the time direction are determined to generate a second delay profile; Setting a detection time of each incoming wave of the first delay profile such that an arrival time of a main wave of the first delay profile matches that of a main wave of a third delay profile in which a copy of the content of a part of the second delay profile within a detection period during which incoming waves is detected is inserted, before and behind a part of the second delay profile within the detection period; and Multiplying values of arrival times of the first delay profile in which the detection time of each incoming wave is offset with values of corresponding arrival times of the third delay profile to output a result of the multiplication as a delay profile of the received orthogonal frequency divider multiplex signal.

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