JP2020065254A - Transmitter and receiver - Google Patents

Abstract

To improve TMCC transmission characteristics in a transmission path environment with large time fluctuations.SOLUTION: A transmitter for a digital broadcasting system that performs transmission with a signal structure in which a predetermined band is composed of a plurality of segments in a frequency direction and a frame is composed of a plurality of symbols in a time direction includes a TMCC signal modulator that performs differential modulation on a TMCC signals arranged on each TMCC carrier of the plurality of segments. The TMCC signal modulator uses a predetermined signal arranged in a carrier different from the TMCC carrier as a differential reference to perform differential modulation on the TMCC signal in the frequency direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a transmitter and a receiver for a digital broadcasting system.

  ISDB-T (Integrated Services Digital Broadcasting-Terrestrial), which is the current terrestrial digital broadcasting, is capable of hierarchical transmission by simultaneously transmitting a plurality of layers having different transmission parameters. Transmission control information such as transmission parameters of each layer is transmitted by a TMCC (Transmission and Multiplexing Configuration Control) signal (for example, refer to Non-Patent Document 1). The same TMCC signal is transmitted by a plurality of TMCC carriers of a plurality of segments, and by performing signal combining on the receiving side, a diversity effect can be obtained and the receiving performance can be improved.

  In recent years, research on next-generation terrestrial digital broadcasting (hereinafter, referred to as “next-generation terrestrial broadcasting”) has been advanced toward the advancement of broadcasting services. Next-generation terrestrial broadcasting is a method that can inherit the segment structure of an OFDM (Orthogonal Frequency Division Multiplexing) signal, which is a feature of ISDB-T, and can multiplex a fixed reception service and a mobile reception service into one modulated wave. . Further, by using an error correction code different from ISDB-T and a new signal structure, frequency utilization efficiency is high and flexible transmission parameter setting can be performed according to the service.

  Since this transmission parameter information is transmitted as a TMCC signal, the receiving device needs to demodulate the TMCC signal before the data signal in order to obtain the transmission parameter information. Therefore, the transmission characteristic of the TMCC signal is required to be higher than that of the data signal.

  Further, in ISDB-T, carrier modulation is performed by applying DBPSK (Differential Binary Phase-Shift Keying) to TMCC signals arranged in respective TMCC carriers of a plurality of segments. DBPSK is a type of differential modulation that adds information to the phase difference between two symbols. As shown in FIG. 1, in the carrier modulation method in ISDB-T TMCC signal transmission, when carrier modulation is performed on the n-th (n ≧ 2) symbol of the TMCC carrier, the (n−1) -th symbol of this TMCC carrier is used. The differential modulation is performed using the symbol of as the differential reference.

"Transmission system of terrestrial digital television broadcasting" standard, ARIB STD-B31, General Incorporated Association

  In the carrier modulation method in the TMCC signal transmission of ISDB-T, the receiving apparatus performs demodulation based on the phase difference between two symbols, assuming that the transmission path responses of two symbols continuous in the time direction are the same. For this reason, in an environment in which the transmission path changes over time, such as a mobile reception environment, fluctuations in the transmission path response between two symbols lead to an increase in error rate, which causes deterioration of reception characteristics.

  In particular, in next-generation terrestrial broadcasting, it is assumed that FFT (Fast Fourier Transform) size is larger than ISDB-T and a parameter having a long symbol length can be set. When such a parameter is used, the influence of the deterioration of the reception characteristics due to the time variation of the transmission path becomes more remarkable due to the expansion of the symbol length.

  Therefore, it is an object of the present invention to provide a transmitting device and a receiving device capable of improving the TMCC transmission characteristics in a transmission path environment with large time fluctuations.

  A transmission device according to a first feature is a transmission device for a digital broadcasting system that performs transmission by a signal structure in which a predetermined band includes a plurality of segments in a frequency direction and a frame includes a plurality of symbols in a time direction. , A TMCC signal modulator that differentially modulates a TMCC signal arranged in each TMCC carrier of the plurality of segments, the TMCC signal modulator being arranged in a carrier different from the TMCC carrier. The gist is to perform differential modulation in the frequency direction on the TMCC signal by using the signal as a differential reference.

  In the first feature, the predetermined signal is a signal arranged in an adjacent carrier adjacent to the TMCC carrier, and the TMCC signal modulator uses a symbol of the predetermined signal as a differential reference in a frequency direction. It is desirable to perform differential modulation in the frequency direction on the symbol of the TMCC signal adjacent to the symbol of the predetermined signal.

  In the first feature, it is preferable that the predetermined signal is a signal different from the data signal and is a signal transmitted at a higher power level than the data signal.

  In the first feature, the power boost ratio of the TMCC signal to the data signal is preferably equal to the power boost ratio of the predetermined signal to the data signal.

  In the first feature, the predetermined signal is preferably an LLch (Low Latency Channel) signal.

  In the first feature, the predetermined band is a partial reception band for mobile reception, and the TMCC signal modulation unit uses the symbols of the predetermined signal as a differential reference within the partial reception band to generate the TMCC signal. It is desirable to apply differential modulation in the frequency direction to the signal.

  A receiving device according to a second feature is a receiving device for a digital broadcasting system that performs transmission by a signal structure in which a predetermined band includes a plurality of segments in a frequency direction and a frame includes a plurality of symbols in a time direction. , A TMCC signal demodulation unit that performs differential demodulation on the TMCC signal arranged in each TMCC carrier of the plurality of segments, and the TMCC signal demodulation unit is arranged in a predetermined carrier different from the TMCC carrier. The gist is to perform differential demodulation in the frequency direction on the TMCC signal using the signal as a differential reference.

  In the second feature, a synchronization processing unit that performs at least frequency synchronization with a signal received from a transmission device is provided, and the predetermined signal is a signal arranged in an adjacent carrier adjacent to the TMCC carrier. And the predetermined signal is transmitted at a power level higher than that of the data signal, and the TMCC signal demodulation unit targets all carriers included in the predetermined band for each symbol and frequency between adjacent carriers. Direction differential demodulation, and the synchronization processing unit correlates the result of adding the differential demodulation result obtained for each symbol for each carrier with the carrier arrangement of the TMCC signal and the predetermined signal. Therefore, it is desirable to detect the frequency error in carrier frequency interval units.

  According to the present invention, it is possible to provide a transmitting device and a receiving device capable of improving the TMCC transmission characteristics in a transmission path environment with large time fluctuations.

It is a figure which shows the carrier modulation method in TMCC signal transmission of ISDB-T. It is a figure for explaining the digital broadcasting system concerning an embodiment. It is a figure which shows the transmitter which concerns on embodiment. It is a figure which shows the carrier modulation method in TMCC signal transmission which concerns on embodiment. It is a figure which shows the receiver which concerns on embodiment. It is a figure which shows an example of the effect of embodiment.

  Embodiments will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

<Digital broadcasting system>
First, the digital broadcasting system according to this embodiment will be described. The digital broadcasting system according to the present embodiment is a broadcasting system compatible with next-generation terrestrial broadcasting. FIG. 2 is a diagram for explaining the digital broadcasting system according to the present embodiment.

(1) Signal Structure The occupied bandwidth of the digital broadcasting system according to this embodiment is, for example, 5.83 MHz or 5.57 MHz. 5.83 MHz is a bandwidth expanded by about 4.7% from ISDB-T, and can increase the transmission capacity. On the other hand, 5.57 MHz has the same bandwidth as ISDB-T.

  Regarding the number of segments, the bandwidth per segment is narrowed to increase from 13 segments of ISDB-T to a maximum of 35 segments, so that the bandwidth can be flexibly allocated to each layer. Further, the transmission parameters such as the modulation multi-level number and the coding rate are more enhanced than those of ISDB-T so that the transmission capacity and the transmission resistance can be set more finely according to the service.

  As the error correction code, an LDPC code and a BCH code, which have a higher error correction capability than ISDB-T, are used. The FFT size can be selected from three types of 8k, 16k, and 32k. If the FFT size is increased, the symbol length can be increased. Therefore, if the physical guard interval lengths are the same, the ratio of the guard interval length to the symbol length is reduced, and the transmission efficiency is improved.

  Further, in the digital broadcasting system according to the present embodiment, the central 9 segments of all 35 segments are set as the band for partially receiving (hereinafter, referred to as “partial receiving band”). The partial reception band is used for transmitting an A layer data signal for mobile reception. Bands other than the partial reception band are called non-partial reception bands. The bandwidth of the partial reception band has expanded to 3.5 times (bandwidth: 1.50 MHz) as compared to the one-segment (bandwidth: 0.43 MHz) of ISDB-T, and by expanding the bandwidth, We are trying to reduce the effects of frequency selective fading.

(2) TMCC Signal Transmission Information transmitted by the TMCC signal is transmission parameters such as occupied bandwidth, modulation scheme in each layer, and coding rate of error correction code. When demodulating / decoding a broadcast wave, the receiving device must obtain such information by the TMCC signal.

  In order to transmit the TMCC signal, a carrier for the TMCC signal (TMCC carrier) is assigned in the OFDM segment. The OFDM frame contains SP (Scattered Pilot) signals and LLch (Low Latency Channel) signals in addition to TMCC signals. The LLch signal corresponds to the AC (Auxiliary Channel) signal of ISDB-T.

  The TMCC signal and the LLch signal are transmitted at the boosted power level with respect to the average power of the data signal, and it is possible to obtain transmission resistance that is strong against errors. Also, by boosting, it plays a role as a pilot signal for frequency synchronization.

  Although the number of TMCC carriers differs depending on the FFT size, since the TMCC signal is transmitted in units of OFDM frames, the product of the number of symbols in an OFDM frame and the number of TMCC carriers in the digital broadcasting system according to the present embodiment is all. The FFT size of is 448 carrier symbols.

  When DBPSK, which is a type of differential modulation, is used as the carrier modulation method, 448 carrier symbols correspond to 448 bits. Of these, the first 40 bits of the OFDM frame are used as a signal for differential reference and frame synchronization, so the remaining 408 bits are assigned as transmission parameter information and parity bits.

  In ISDB-T, the same TMCC signal is transmitted in each segment, but in the digital broadcasting system according to the present embodiment, different TMCC signals are transmitted in the partial reception band and the non-partial reception band.

(3) TMCC Signal Transmission in Non-Partial Reception Band The TMCC signal includes system identification, partial reception flag, transmission parameter information of each layer, and the like, and the amount of information is 244 bits. All of this information is transmitted in the non-partial reception band. The 244 bits are divided into two and encoded with the shortened code (204, 122) of the difference set cyclic code (273, 191). Two encoded 204-bit coding blocks form a 408-bit TMCC signal.

  Since the same TMCC signal is transmitted in each segment of the non-partial reception band having 26 segments, the receiving apparatus can combine and receive 26 carrier symbols and enhance the reception resistance of the TMCC signal.

(4) TMCC signal transmission of partial reception band Since the partial reception band is 9 segments, the same transmission method as non-partial reception can only combine 9 carrier symbols. Therefore, the amount of information of the TMCC signal to be transmitted is reduced in order to improve the transmission characteristic within the limited number of segments.

  Since the partial reception band is a band for transmitting the A layer for mobile reception, the TMCC information bit is limited to only the information necessary for receiving the A layer, and is 122 bits which is half the total amount of information. There is. As the error correction code, the same difference set cyclic code (204, 122) as the non-partial reception band is used.

  By duplicating and concatenating the encoded 204-bit coded blocks, a 408-bit TMCC signal is formed. That is, in the partial reception band, the same TMCC signal can be transmitted twice within one segment.

  Within the partial reception band, the TMCC signal for partial reception is transmitted using all nine segments regardless of the number of segments in the A layer. Therefore, the receiving device can combine and receive 18 carrier symbols and can enhance the reception resistance of the TMCC signal.

<Transmitting device>
Next, the transmission device according to the present embodiment will be described. In the following, the TMCC signal transmission in the partial reception band will be mainly described. FIG. 3 is a diagram showing the transmission device 1 according to the present embodiment. The transmitter 1 includes a data signal and a control signal in an OFDM frame for transmission. The control signal includes an LLch signal, a TMCC signal, and an SP signal.

  As illustrated in FIG. 3, the transmission device 1 includes an LLch signal generation unit 11, an LLch signal modulation unit 12, a TMCC signal generation unit 13, a TMCC signal modulation unit 14, an SP signal generation unit 15, and an SP signal modulation. It includes a unit 16, an OFDM frame configuration unit 17, and a transmission unit 18.

  The LLch signal generation unit 11 generates an LLch signal and outputs the generated LLch signal to the LLch signal modulation unit 12. The LLch signal corresponds to the AC signal of ISDB-T, and includes additional information regarding broadcasting (for example, additional information regarding transmission control and earthquake motion warning information). Further, the LLch signal is set so that the transmission delay is smaller than that of the data signal.

  The LLch signal modulation unit 12 performs carrier modulation by differential modulation on the LLch signal input from the LLch signal generation unit 11, and outputs the LLch signal after carrier modulation to the OFDM frame configuration unit 17.

  The LLch signal modulator 12 uses DBPSK, which is a type of differential modulation, as a carrier modulation method. The LLch signal modulator 12 may use DQPSK (Differential Quadrature Phase Shift Keying), which is a type of differential modulation, as a carrier modulation method.

  The TMCC signal generation unit 13 generates a TMCC signal and outputs the generated TMCC signal to the TMCC signal modulation unit 14. The information included in the TMCC signal is transmission parameters such as occupied bandwidth, modulation scheme in each layer, and coding rate of error correction code.

  An error correction coding unit (not shown) may be provided between the TMCC signal generation unit 13 and the TMCC signal modulation unit 14. The error correction coding unit performs error correction coding on the TMCC signal input from the TMCC signal generation unit 13, and outputs the TMCC signal after the error correction coding to the TMCC signal modulation unit 14.

  The TMCC signal modulation unit 14 performs carrier modulation by differential modulation on the input TMCC signal, and outputs the carrier-modulated TMCC signal to the OFDM frame configuration unit 17.

  The TMCC signal modulator 14 uses DBPSK, which is a type of differential modulation, as a carrier modulation method. The TMCC signal modulator 14 may use DQPSK, which is a type of differential modulation, as the carrier modulation method.

  As a carrier modulation method for the LLch signal and the TMCC signal, it is desirable to use DBPSK or DQPSK that is envelope modulation, and it is desirable to use the same carrier modulation method for the LLch signal and the TMCC signal. However, the LLch signal and the TMCC signal may use different carrier modulation methods.

  The TMCC signal modulator 14 differentially modulates the TMCC signals arranged in the respective TMCC carriers of the plurality of segments forming the partial reception band (predetermined band). FIG. 4 is a diagram showing a carrier modulation method in TMCC signal transmission according to this embodiment.

  As shown in FIG. 4, the TMCC signal modulator 14 performs differential modulation in the frequency direction on the TMCC signal using a predetermined signal arranged in a carrier different from the TMCC carrier as a differential reference. By performing the carrier modulation of the TMCC signal in the frequency (carrier) direction instead of the time (symbol) direction, it is possible to reduce the influence of the deterioration of the reception characteristic even in an environment where the time variation of the transmission path occurs such as a mobile reception environment. .

  In the present embodiment, the predetermined signal used as the differential reference is the LLch signal. When the LLch signal is used as the differential reference, the carrier arrangement is such that the carrier for the LLch signal (LLch carrier) and the TMCC carrier are adjacent to each other.

  The TMCC signal modulator 14 uses the symbols of the LLch signal arranged in the adjacent carrier adjacent to the TMCC carrier as a differential reference, and determines the frequency direction with respect to the symbol of the TMCC signal adjacent to the symbol of the LLch signal in the frequency direction. Differential modulation of. By using adjacent carriers as the differential reference, it is possible to reduce the influence of fluctuations in the transmission line response in the frequency direction.

  When the LLch signal is used as the differential reference, first, the LLch signal modulation section 12 performs differential modulation in the time direction on the LLch signal by the same method as the modulation method shown in FIG. Next, the TMCC signal modulator 14 performs differential modulation in the frequency direction on the symbols of the TMCC carriers adjacent in the frequency direction, using the LLch signal after the differential modulation as a differential reference.

  The differential reference LLch signal is boosted like the TMCC signal and is a signal transmitted at a higher power level than the data signal. Since the LLch signal has a strong transmission resistance against errors, it is possible to reduce the error rate of the TMCC signal by using such an LLch signal as a differential reference.

  Since differential modulation is performed with a pair of a LLch carrier symbol and a TMCC carrier symbol adjacent to the LLch carrier symbol, it is desirable that these two carriers have the same amplitude value (boost ratio). That is, the power boost ratio of the TMCC signal to the data signal is preferably equal to the power boost ratio of the LLch signal to the data signal. For example, both the boost ratios of the LLch signal and the TMCC signal may be set to 1.99. Also, the dynamic range can be suppressed by making the amplitude values (boost ratios) of these two carriers the same.

  The SP signal generation unit 15 generates an SP signal and outputs the generated SP signal to the SP signal modulation unit 16.

  The SP signal modulator 16 performs carrier modulation on the SP signal input from the SP signal generator 15 and outputs the carrier-modulated SP signal to the OFDM frame configuration unit 17.

  The OFDM frame configuration unit 17 receives the LLch signal input from the LLch signal modulation unit 12, the TMCC signal input from the TMCC signal modulation unit 14, and the SP signal input from the SP signal generation unit 15 together with the data signal. It is assigned to the OFDM frame and is output to the transmission unit 18.

  The transmission unit 18 transmits the OFDM frame input from the OFDM frame configuration unit 17.

<Receiver>
Next, the receiving apparatus according to this embodiment will be described. FIG. 5 is a diagram showing the receiving device 2 according to the present embodiment.

  As shown in FIG. 5, the receiving device 2 includes a receiving unit 21, a TMCC signal decoding unit 22, and a data signal decoding unit 23.

  The receiver 21 receives a signal (OFDM frame) transmitted from the transmitter 1. The reception unit 21 includes a synchronization processing unit 21a that performs each synchronization process (symbol synchronization, frequency synchronization, OFDM frame synchronization) and a TMCC signal demodulation unit 21b that performs differential demodulation in the frequency direction.

  Regarding the symbol synchronization, the synchronization processing unit 21a can estimate the leading position of the effective symbol from these correlations by utilizing the fact that the guard interval period of OFDM is the same as the latter half of the effective symbol. Further, the synchronization processing unit 21a can estimate the carrier frequency error in a narrow band (within the carrier frequency interval) from the phase of this correlation.

  Furthermore, in order to estimate the carrier frequency error of the wide band (carrier frequency interval unit) of the conventional method (ISDB-T etc.), the carrier which is assigned to the fixed carrier number of the TMCC signal or the LLch signal and is boosted is selected. We are using. The synchronization processing unit 21a can estimate the position of the boosted carrier by adding and averaging the powers of the signals of all OFDM carriers. Frequency error can be detected.

  In the present embodiment, wideband frequency synchronization can be performed as in the above-described conventional method, but wideband carrier frequency error is detected and wideband frequency synchronization is performed by the following method.

  When the receiving unit 21 receives the signal, the positions of the LLch signal and the TMCC signal are unknown. Therefore, first, the TMCC signal demodulation unit 21b performs differential demodulation between adjacent carriers in the frequency direction for all carriers. Specifically, differential demodulation in the frequency direction is performed (total number of carriers + α) times per symbol. Here, α is the maximum value of the carrier frequency error in the detectable wide band (unit of carrier frequency interval).

  Next, the TMCC signal demodulation unit 21b performs differential demodulation between adjacent carriers for each symbol (each symbol number). Then, the synchronization processing unit 21a adds the result of the differential demodulation obtained for each symbol for each carrier (for each carrier number). As a result, the result of differential demodulation with the combination of the LLch signal and the TMCC signal has a larger power than other carriers. The synchronization processing unit 21a detects a wideband carrier frequency error by obtaining a correlation between the addition result for each carrier and the actual arrangement of the LLch signal and the TMCC signal, and obtains wideband frequency synchronization.

  In this way, by detecting the carrier frequency error based on the signal after the differential demodulation in the frequency direction, it becomes easier to find the peaks of the LLch signal and the TMCC signal as compared with the simple power addition as in the conventional method. .

  The reception unit 21 outputs the data signal extracted from the reception signal after the synchronization processing to the data signal decoding unit 23, and also outputs the TMCC signal demodulated by the TMCC signal demodulation unit 21b to the TMCC signal decoding unit 22.

  The TMCC signal decoding unit 22 performs error correction decoding on the TMCC signal input from the receiving unit 21, and outputs the TMCC signal after error correction decoding to the data signal decoding unit 23.

  The data signal decoding unit 23 demodulates and decodes the data signal based on the TMCC information (transmission parameter) included in the input TMCC signal, and outputs the decoded data signal.

<Action / effect>
The transmitter 1 and the receiver 2 according to the present embodiment perform differential modulation / demodulation in the frequency direction on the TMCC signal using the symbols of the LLch signal arranged on the LLch carrier adjacent to the TMCC carrier as a differential reference. . As described above, the carrier modulation / demodulation of the TMCC signal is performed not in the time (symbol) direction but in the frequency (carrier) direction, and the differential modulation is performed between the adjacent carriers within the same symbol time. Stay within one symbol time. Therefore, the TMCC transmission characteristics can be improved in a transmission path environment in which the time variation is large.

  FIG. 6 is a diagram showing an example of the effect of the present embodiment, and shows a case where differential modulation in the time direction is performed on the TMCC signal and a case where differential modulation in the frequency direction according to the present embodiment is performed. The required C / N with respect to the moving speed is shown in comparison.

  As shown in FIG. 6, when the differential reference in the time direction is applied to the TMCC signal, the required C / N rapidly increases from the moving speed of the middle of 50 km / s, while the present embodiment does not. In the case of performing the differential modulation in the frequency direction according to (1), the required C / N does not increase sharply up to around 160 km / s, and the speed tolerance is significantly improved.

<Other embodiments>
In the above embodiment, the TMCC signal transmission in the partial reception band has been mainly described. Different TMCC information is transmitted in the partial reception band and the non-partial reception band. In the partial reception band, only the transmission control information for decoding the A layer is transmitted, and in the non-partial reception band, the transmission control information of all the layers is transmitted. Therefore, for the non-partial reception band, TMCC signal transmission (that is, differential modulation in the time direction) similar to the conventional one may be used. In this case, since there is no limitation on the carrier modulation method of the LLch signal, 64QAM modulation or the like may be applied to the LLch signal. Alternatively, the method according to the above-described embodiment may be applied to the non-partial reception band.

  In the above-described embodiment, an example of performing differential modulation of the TMCC signal using the LLch signal as the differential reference has been described, but instead of using the LLch signal as the differential reference, a new signal for the differential reference is used. May be provided to perform differential modulation of the TMCC signal using the new signal as a differential reference. Alternatively, differential modulation of the TMCC signal may be performed using the SP signal as the differential reference.

  In the above-described embodiment, an example of applying the frequency-direction differential modulation to the TMCC signal has been described, but the frequency-direction differential modulation may be applied to the LLch signal. In this case, the differential reference may be the SP signal or the differential reference may be a new signal.

  In the above-mentioned embodiment, the arrangement of SP signal carriers (SP carriers) was not particularly mentioned. Since SP carriers are allocated at a predetermined carrier interval, a set of TMCC carrier and LLch carrier may be allocated within the predetermined carrier interval.

  A program that causes a computer to execute each process performed by the transmission device 1 and a program that causes a computer to perform each process performed by the reception device 2 may be provided. The program may be recorded on a computer-readable medium. A computer readable medium can be used to install the program on a computer. Here, the computer-readable medium in which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, but may be a recording medium such as a CD-ROM or a DVD-ROM.

  Further, the transmission device 1 may be configured as a semiconductor integrated circuit (chip set, SoC) by integrating functional units (circuits) that execute the processes performed by the transmission device 1. Similarly, the functional unit (circuit) that executes each process performed by the receiving device 2 may be integrated to configure the receiving device 2 as a semiconductor integrated circuit (chip set, SoC).

  Although the embodiments have been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the spirit of the invention.

1: Transmitting device 2: Receiving device 11: LLch signal generating unit 12: LLch signal modulating unit 13: TMCC signal generating unit 14: TMCC signal modulating unit 15: SP signal generating unit 16: SP signal modulating unit 17: OFDM frame configuration unit 18: transmitter 21: receiver 21a: synchronization processor 21b: TMCC signal demodulator 22: TMCC signal decoder 23: data signal decoder

Claims (5)

A transmitting device for a digital broadcasting system that performs transmission by a signal structure in which a predetermined band is composed of a plurality of segments in the frequency direction and a frame is composed of a plurality of symbols in the time direction,
A TMCC signal modulator for performing differential modulation on the TMCC signals arranged in each TMCC carrier of the plurality of segments,
The transmitter according to claim 1, wherein the TMCC signal modulator uses a predetermined signal arranged in a carrier different from the TMCC carrier as a differential reference to perform differential modulation in the frequency direction on the TMCC signal. The predetermined signal is a signal arranged in an adjacent carrier adjacent to the TMCC carrier,
The TMCC signal modulator uses the symbol of the predetermined signal as a differential reference and performs differential modulation in the frequency direction on the symbol of the TMCC signal adjacent to the symbol of the predetermined signal in the frequency direction. The transmitting device according to claim 1. The predetermined signal is a signal different from the data signal,
The transmitter according to claim 1 or 2, wherein the TMCC signal and the predetermined signal are transmitted at a higher power level than the data signal. A receiving device for a digital broadcasting system that performs transmission by a signal structure in which a predetermined band is composed of a plurality of segments in the frequency direction and a frame is composed of a plurality of symbols in the time direction,
A TMCC signal demodulation unit that performs differential demodulation on the TMCC signals arranged in each TMCC carrier of the plurality of segments,
The receiving device, wherein the TMCC signal demodulation unit performs differential demodulation in the frequency direction on the TMCC signal using a predetermined signal arranged on a carrier different from the TMCC carrier as a differential reference. Further comprising a synchronization processing unit that performs at least frequency synchronization with respect to the signal received from the transmission device,
The predetermined signal is a signal arranged in an adjacent carrier adjacent to the TMCC carrier,
The TMCC signal and the predetermined signal are transmitted at a higher power level than the data signal,
The TMCC signal demodulation unit performs differential demodulation in the frequency direction between adjacent carriers for each symbol for all carriers included in the predetermined band,
The synchronization processing unit correlates the result of adding the result of the differential demodulation obtained for each symbol for each carrier and the carrier arrangement of the TMCC signal and the predetermined signal to obtain a carrier frequency interval unit. The receiver according to claim 4, wherein a frequency error is detected.

Images