JP4425267B2 - Digital terrestrial broadcast retransmission equipment - Google Patents

Description

  The present invention relates to a terrestrial digital broadcast retransmission apparatus, and more particularly to a retransmission apparatus that receives a segment of a partial reception unit of terrestrial digital television broadcast or a terrestrial digital audio broadcast and retransmits the received signal.

  Japanese terrestrial digital television broadcasting adopts an OFDM (Orthogonal Frequency Division Multiplex) modulation system called ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) system, and has 13 segments (total bandwidth) of 6 segments (total bandwidth). Broadcast data.

  A television set in a home receives these 13 segments at once by a fixed antenna, but in broadcasting for mobile / mobile objects such as mobile phones and PDAs (Personal Digital Assistants) So-called partial reception is performed, in which only one central segment is received.

  Here, it is necessary for the mobile / mobile broadcasting segment to be able to be received well in the shade of an outdoor building, in a building, in an underground mall, etc. For this purpose, the segment of the partial receiver is retransmitted. A transmission device is required.

  Conventionally, the following four methods are known as retransmission methods for terrestrial digital broadcasting. That is, the first retransmission method is realized by a single frequency network that transmits signals having the same contents from a plurality of transmitting stations or relay stations using the same frequency when retransmitting all 13 segments. (See, for example, Patent Documents 1, 2, and 3). The second retransmission method is realized by a two-frequency network that performs frequency conversion on the received signal received by the relay station and transmits at a frequency different from the received frequency when retransmitting all 13 segments. Yes (see Non-Patent Document 1, for example).

  The third retransmission method is to construct a network that performs only partial reception, extract only the partial reception unit with a filter, and retransmit only the partial reception unit (for example, see Patent Document 4). reference). In the fourth retransmission method, by constructing a network that performs only partial reception, only a partial reception unit is extracted by a filter, Fourier transform is performed, and a plurality of segments are concatenated and retransmitted by frequency domain processing. (For example, refer to Patent Document 5).

JP-A-10-75262 JP-A-10-75263 JP-A-10-28105 JP 2005-341195 A JP 2006-109283 A Aiichiro Totake et al., “Digital Terrestrial Broadcasting Using OFDM-Examination of Dual Frequency Broadcasting”, Proceedings of the Annual Conference of the Television Society of Japan, pages 277-278

  In the first and second retransmission methods described above, in the case of digital terrestrial television broadcasting, transmission data of the entire 13 segments is retransmitted using a bandwidth of 6 MHz per channel. However, with this re-transmission method, even when re-sending to a portable / mobile object such as an outdoor building, inside a building, or underground mall, only one segment of the partial receiving unit needs to be re-transmitted. First, the entire 6 MHz signal bandwidth of 13 segments per channel must be retransmitted. For example, when retransmission is performed for 8 channels using two frequencies, it is necessary to secure a band with a channel width of 48 MHz (6 MHz × 8 channels) for 8 channels. In this case, there is a problem that it is difficult to secure such a band because the current domestic transmission allocation frequency is crowded.

  In the third retransmission method described above, only the partial receiving unit is extracted and retransmitted. However, since the band to be retransmitted is 6 MHz per channel, the band of 48 MHz is eventually obtained in the case of 8 channels. There is a problem similar to the first and second retransmission methods described above in that it is necessary. In addition, there is a problem that the characteristics of fixed reception near the retransmission point may be deteriorated.

  In addition, the fourth retransmission method described above is to retransmit by concatenating a plurality of segments. However, since processing in the frequency domain is required, Fourier transform and inverse Fourier transform are performed. There has been a problem that the delay time from reception of a signal to retransmission is increased and the circuit scale is also increased.

  Therefore, the present invention has been made to solve such a problem, and the purpose of the present invention is to realize a reduction in the delay time and a reduction in size in a terrestrial digital broadcast retransmitting device without assigning unnecessary frequencies. Another object of the present invention is to provide a broadcast re-transmission device for portable / mobile objects.

  In order to solve the above-mentioned problem, the digital terrestrial broadcast retransmission apparatus according to the present invention extracts only the terrestrial digital broadcast wave partial reception unit with a filter, and performs digital processing in the time domain only to generate a plurality of digital terrestrial broadcast wave parts. The receiving unit is connected to each adjacent segment and retransmitted as one terrestrial digital broadcast wave. As a result, retransmission can be performed with a small bandwidth without performing Fourier transform or inverse Fourier transform.

  That is, the terrestrial digital broadcast retransmission apparatus according to the present invention receives a plurality of terrestrial digital broadcasts composed of a plurality of segments, extracts one segment from each of these terrestrial digital broadcast waves, and connects the extracted segments. In a digital terrestrial broadcast retransmission apparatus that retransmits digital terrestrial broadcast waves, the tuner unit includes a plurality of tuner units, a plurality of digital processing units corresponding to the tuner units, an addition unit, and a retransmission unit, respectively. Is selected by one of a plurality of received terrestrial digital broadcast waves, and is converted by the reception conversion means for converting an RF band signal of the broadcast wave into an IF band signal and the reception conversion means. AD conversion means for converting the IF signal into a digital IF signal, and the digital data converted by the AD conversion means Quadrature demodulation means for performing quadrature demodulation on the IF signal and outputting an equivalent baseband signal, and the digital processing section extracts one segment from the equivalent baseband signal output by the quadrature demodulation means of the tuner section Filter means; and segment placement means for frequency-converting an equivalent baseband signal of one segment extracted by the filter means to a position for connecting a plurality of segments, and the adder unit Means for adding and synthesizing the equivalent baseband signals of each one of the segments frequency-converted by the segment arrangement means of the digital processing unit, and the retransmitting unit adds the equivalent baseband signal synthesized by the adding unit. Quadrature modulation means for performing quadrature modulation and outputting a digital IF signal, and the quadrature modulation means DA converter means for converting the digital IF signal output from the analog IF signal, and the analog IF signal converted by the DA converter means into an RF band signal for re-transmission as a terrestrial digital broadcast wave, Transmission conversion means for amplifying the converted signal.

  As described above, according to the present invention, in a terrestrial digital broadcast retransmitting apparatus, it is possible to realize a retransmitting apparatus that has a short delay time and can be miniaturized without performing unnecessary frequency allocation.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
The embodiment of the present invention will be described by taking as an example a retransmission apparatus that receives and retransmits terrestrial digital television broadcasts.

  FIG. 2 is a diagram showing the configuration and numbers of ISDB-T segment. In the ISDB-T system, about 5600 subcarriers constituting an OFDM signal are divided into 13 groups, and each of them is referred to as a segment. Segments are distinguished by segment numbers of 0 to 12, and the segment with segment number 0 is a segment of a partial receiving unit, and broadcast data for mobile / mobile objects is allocated. These 13 segments correspond to one channel, and the bandwidth is 6 MHz. A broadcaster is assigned one channel with a bandwidth of 6 MHz composed of 13 segments, and each broadcaster broadcasts an ISDB-T OFDM signal in the assigned one channel.

  FIG. 3 is a diagram showing an example in which each one-segment part of 8 channels is connected as a configuration example of the reception channel and the transmission channel in the digital terrestrial broadcast retransmission apparatus. As shown in FIG. 3, one of the eight channels (UHF13, 14, 15, 16, 17, 18, 19, 20ch) is assigned to a plurality of broadcasters. To do. The terrestrial digital broadcast re-transmission apparatus receives the plurality of terrestrial digital broadcast waves, extracts the partial reception unit of segment number 0 from each terrestrial digital broadcast wave, connects the partial reception units, and connects the signals. Is a device that transmits a free RF signal, for example, UHF53ch, as a retransmission signal.

  Hereinafter, the terrestrial digital broadcast retransmission apparatus will be described in detail with reference to Examples 1 to 10. The digital terrestrial broadcast retransmission apparatus according to the first embodiment receives digital terrestrial television broadcasts without performing Fourier transform for each channel system, and retransmits the extracted partial reception units connected to each other. The digital terrestrial broadcast retransmission apparatus according to the second embodiment performs reception processing without performing Fourier transform for each system as in the first embodiment, but adds a GI (Guard Interval) to each extracted partial reception unit. The data is retransmitted after changing. The digital terrestrial broadcast retransmission apparatus according to the third embodiment retransmits the extracted partial reception units at the same symbol timing. The digital terrestrial broadcast retransmission apparatus according to the fourth embodiment retransmits each extracted partial reception unit in accordance with each symbol timing and SP (Scattered Pilot) pattern. The terrestrial digital broadcast re-transmission apparatus according to the fifth embodiment re-transmits the extracted partial reception units at the same frame timing. The terrestrial digital broadcast retransmission apparatus according to the embodiments 6 to 10 adds a TS (Transport Stream) signal independently generated separately from the terrestrial digital television broadcast and transmits it together with the terrestrial digital television broadcast. Each of the methods of Examples 1 to 5 is used.

  First, Example 1 will be described. FIG. 1 is a block diagram showing a configuration (Example 1) of a digital terrestrial broadcast retransmission apparatus according to an embodiment of the present invention. The retransmission apparatus 1 includes a receiving antenna unit 100, N tuner units 200 (200-1, 200-2,..., 200-N), and N digital processing units 311 (311-1, 311- 2,..., 311 -N), an adder circuit 400, a retransmitting unit 500, and a transmitting antenna unit 600. The tuner unit 200 and the digital processing unit 311 are configured by N systems, and each system is configured by the same circuit. Therefore, only one system will be described below. The tuner unit 200 includes a reception conversion circuit 201, an AD conversion circuit 202, and an orthogonal demodulation circuit 203. The digital processing unit 311 includes an LPF (Low Pass Filter) circuit 301 and a segment arrangement circuit 302, and retransmits. The unit 500 includes an orthogonal modulation circuit 501, a DA conversion circuit 502, and a transmission conversion circuit 503. Note that N ≦ 13 (the same applies hereinafter).

  The terrestrial digital broadcast received by the receiving antenna unit 100 is distributed to the number of terrestrial digital broadcast waves (N waves) by a distributor (not shown). When the tuner unit 200 inputs an RF signal that is a distributed terrestrial digital broadcast, the reception conversion circuit 201 of the tuner unit 200 uses the input RF signal once as an intermediate frequency (for example, 57 MHz used in a home receiver). ), And after passing through a SAW (Surface Acoustic Wave) filter, the frequency is converted again to a low frequency (for example, 4 MHz which is half of the FFT (Fast Fourier Transform) frequency). As a result, only channels preset for each system are selected.

  The AD conversion circuit 202 receives the signal frequency-converted by the reception conversion circuit 201 and performs A / D conversion into a digital signal at a sampling frequency (for example, 16 MHz which is twice the FFT frequency). The quadrature demodulation circuit 203 receives the digital signal A / D converted by the AD conversion circuit 202, performs quadrature demodulation, and converts it into an equivalent baseband signal.

  The LPF circuit 301 of the digital processing unit 311 receives the equivalent baseband signal converted by the quadrature demodulation circuit 203 and extracts only the signal of the one-segment part (partial reception unit) by filtering. The segment placement circuit 302 receives the one-segment signal extracted by the LPF circuit 301 and performs frequency conversion into a segment to be placed when it is connected to one equivalent baseband signal.

  The adder circuit 400 inputs the equivalent baseband signal of the one-segment part digitally processed by the N systems of digital processing units 311 and adds and synthesizes these equivalent baseband signals.

  The quadrature modulation circuit 501 of the retransmitting unit 500 receives the equivalent baseband signal added and synthesized by the adder circuit 400, and performs quadrature modulation to convert it. The DA conversion circuit 502 inputs the digital signal converted by the quadrature modulation circuit 501 and uses the same sampling frequency as that of the AD conversion circuit 202 (for example, 16 MHz which is four times 4 MHz) to convert the input digital signal to D / D. A conversion is performed to generate a low-frequency (for example, 4 MHz) signal. The transmission conversion circuit 503 inputs the low frequency signal D / A converted by the DA conversion circuit 502, converts the frequency to an intermediate frequency (for example, IF signal frequency 37.15 MHz), and then retransmits the signal. The frequency is converted again to an RF signal and amplified to a desired transmission power. The RF signal thus frequency-converted and amplified by the transmission conversion circuit 503 is retransmitted via the transmission antenna unit 600.

  As described above, according to the terrestrial digital broadcast retransmitting apparatus 1 according to the first embodiment, only a partial reception unit that is a service broadcast for mobile / mobile terrestrial digital broadcasts is extracted with a filter, and Fourier transform and inverse Fourier transform are performed. Instead, only by digital processing in the time domain, a plurality of terrestrial digital broadcast wave partial reception units are connected to adjacent segments and retransmitted as one RF signal. Thereby, it can retransmit with less bandwidth (1 channel = 6 MHz), without assigning a useless frequency toward receiving apparatuses, such as an outdoor building shadow, the inside of a building, and an underground mall. Further, it is not necessary to perform Fourier transform and inverse Fourier transform on the main line data to be retransmitted, and these circuits are unnecessary, so that the delay time is short and a simple miniaturization can be realized.

  Next, Example 2 will be described. The second embodiment eliminates frequency component errors caused by jitter included in the local frequency when the reception conversion circuit 201 performs frequency conversion, prevents inter-carrier interference in the adder circuit 400, and prevents the LPF circuit 301. This is to remove signal distortion caused by the filtering process.

  FIG. 4 is a block diagram showing the configuration (Example 2) of the digital terrestrial broadcast retransmission apparatus according to the embodiment of the present invention. The retransmission apparatus 2 includes a reception antenna unit 100 (not shown), N tuner units 200, N digital processing units 312, an adder circuit 400, a retransmission unit 500, and a transmission antenna unit 600 (not shown). ). Since the digital processing unit 312 includes N systems, and each system includes the same circuit, only one system will be described below. The digital processing unit 312 includes an LPF circuit 301, a frequency error correction circuit 303, a symbol synchronization detection circuit 304, a GI replacement circuit 305, and a segment arrangement circuit 302. Comparing the retransmission apparatus 1 according to the first embodiment shown in FIG. 1 and the retransmission apparatus 2, both apparatuses include a reception antenna unit 100, a tuner unit 200, an adder circuit 400, a retransmission unit 500, and a transmission antenna unit 600. However, in addition to the configuration of the digital processing unit 311 of the retransmission apparatus 1, the digital processing unit 312 of the retransmission apparatus 2 includes a frequency error correction circuit 303, a symbol synchronization detection circuit 304, and a GI. The difference is that a replacement circuit 305 is provided. In the following, in FIG. 4, the same reference numerals as those in FIG.

  When the digital processing unit 312 inputs the equivalent baseband signal of the channel selected by the tuner unit 200, the LPF circuit 301 extracts only the signal of the one-segment part (partial reception unit) by filtering. The output of the LPF circuit 301 is divided into two, one is input to the frequency error correction circuit 303 and the other is input to the symbol synchronization detection circuit 304.

  The symbol synchronization detection circuit 304 receives the one-segment signal extracted by the LPF circuit 301, detects the frequency error amount of the one-segment signal and the head position of the symbol, and sends the frequency error amount to the frequency error correction circuit 303. The symbol head position information is output to the GI replacement circuit 305.

  An example of detecting symbol synchronization is shown below. In general, an OFDM symbol is composed of a guard period and an effective symbol period, and a signal in the guard period is cyclically copied from a part after the effective symbol. The symbol synchronization detection circuit 304 obtains a guard correlation using this configuration, and detects the frequency error amount and the symbol head position. Specifically, an input signal (a signal composed of a guard period and an effective symbol period) and a signal obtained by delaying the input signal by an effective symbol period are multiplied by these signals to shift the guard period width. By obtaining the average, the guard correlation of both signals is obtained. Then, a point where the obtained guard correlation value has a peak is detected as a symbol boundary (ie, the head position of the symbol). Also, the correlation (Sii) between the I-axis data of the input signal (equivalent baseband signal) and the I-axis data delayed by the effective symbol period, and the I-axis data of the input signal and the effective symbol period are delayed by the effective symbol period. Correlation (Siq) with Q-axis data is obtained, and the frequency error amount is detected based on these correlation values. For details of the detection method of the symbol head position and the frequency error amount, see “Takashi Seki et al.,“ Examination of a new frequency synchronization method using a guard period in OFDM ”, Television Society Technical Report, August 24, 1995. Refer to “day”.

  The frequency error correction circuit 303 receives the one-segment signal from the LPF circuit 301, receives the frequency error amount from the symbol synchronization detection circuit 304, and uses the input frequency error amount as the frequency error in the input one-seg signal. To correct. In the reception conversion circuit 201, since the local frequency used for frequency conversion includes jitter, an error occurs in the frequency component. In the addition circuit 400, when combining the signals of the one-segment parts of the respective channels May cause interference. This frequency error correction circuit 303 can prevent inter-carrier interference caused by a frequency component error at the time of frequency conversion.

  The GI replacement circuit 305 receives the one-segment signal corrected from the frequency error correction circuit 303, receives the symbol head position information from the symbol synchronization detection circuit 304, and inputs the input symbol to the input one-seg signal. A signal of 1 symbol length is extracted with reference to the head position information, and the GI is replaced.

  FIG. 5 is a diagram for explaining the processing of the GI replacement circuit 305. The GI replacement circuit 305 uses the fact that the signal of the guard period among the OFDM symbols composed of the guard period and the effective symbol period is copied to the rear part of the effective symbol, The distortion at the beginning of the signal of 1 symbol length is removed by the following processing. First, the GI replacement circuit 305 identifies a symbol head position based on the input symbol head position information (1), and extracts a signal of an effective symbol length from the position of GI / 2 as a starting point (2). . Then, the signals from the head of the extracted effective symbol length signal to the position of GI / 2 are rearranged and rearranged (3), and the rear part of the rearranged signal according to the preset GI ratio Is added as a GI to the head (4). In this way, a new one-symbol signal is obtained. In the LPF circuit 301, there is a possibility that distortion will occur at the beginning and the back of one symbol length due to the filter processing. With this GI reassignment circuit 305, signal distortion caused by the filter processing can be removed.

  Returning to FIG. 4, the segment arrangement circuit 302 receives the signal of the one-segment part whose GI has been replaced by the GI replacement circuit 305, and converts the frequency into a segment that is arranged when it is connected to one equivalent baseband signal I do.

  As described above, according to the terrestrial digital broadcast retransmission apparatus 2 according to the second embodiment, the same effects as those of the first embodiment can be obtained. Further, the frequency error correction circuit 303 can eliminate frequency component errors caused by jitter included in the local frequency when the reception conversion circuit 201 performs frequency conversion, and can prevent inter-carrier interference in the addition circuit 400. . Further, the GI replacement circuit 305 can remove distortion at the beginning and the rear of the 1-symbol length of the signal generated by the filter processing of the LPF circuit 301. As a result, in the receiving device that receives the retransmission signal from the retransmission device 2, the accuracy of symbol synchronization is improved, the frequency error correction amount is accurate, and deterioration in the retransmission device 2 can be reduced.

  Next, Example 3 will be described. The third embodiment eliminates frequency component errors caused by jitter included in the local frequency when the reception conversion circuit 201 performs frequency conversion, prevents inter-carrier interference in the adder circuit 400, and eliminates one segment of each system. This retransmits the partial signals in accordance with the symbol timing.

  FIG. 6 is a block diagram showing the configuration (Example 3) of the digital terrestrial broadcast retransmission apparatus according to the embodiment of the present invention. The retransmission apparatus 3 includes a reception antenna unit 100 (not shown), N tuner units 200, N digital processing units 313, a delay time adjustment circuit 307-3, an addition circuit 400, a retransmission unit 500, and The transmitting antenna unit 600 (not shown) is configured. Since the digital processing unit 313 is configured by N systems, and each system is configured by the same circuit, only one system will be described below. The digital processing unit 313 includes an LPF circuit 301, a frequency error correction circuit 303, a symbol synchronization detection circuit 304, a digital delay circuit 306, and a segment arrangement circuit 302. Comparing the retransmission apparatus 2 of the second embodiment shown in FIG. 4 with the retransmission apparatus 3, the reception antenna unit 100, the tuner unit 200, the addition circuit 400, the retransmission unit 500, and the transmission antenna unit 600 are both used in both apparatuses. However, the digital processing unit 313 of the retransmission apparatus 3 has a different configuration from the digital processing unit 312 of the retransmission apparatus 2, and the retransmission apparatus 3 further adjusts the delay time. The difference is that a circuit 307-3 is provided. In FIG. 6, the same reference numerals as those in FIG. 4 are given to portions common to FIG. 4, and detailed description thereof is omitted.

  The symbol synchronization detection circuit 304 receives the one-segment signal extracted by the LPF circuit 301, detects the frequency error amount of the signal of the one-segment portion and the head position of the symbol by guard correlation, and corrects the frequency error amount to the frequency error. The signal is output to the circuit 303, and the symbol head position information is output to the delay time adjustment circuit 307-3.

  The delay time adjustment circuit 307-3 inputs the symbol head position information from the symbol synchronization detection circuit 304 of the digital processing units 313-1 to 313-1 of each system, and uses the reception timing of any equivalent baseband signal as a reference. Thus, the delay time of each system is calculated so that the symbol head timings of the equivalent baseband signals of each system match.

  The digital delay circuit 306 of each system receives the one-segment signal corrected by the frequency error correction circuit 303 and the delay time calculated by the delay time adjustment circuit 307-3 to correct the frequency error. Delay the signal by the delay time. Since the tuner processing by the tuner unit 200 and the digital processing by the digital processing unit 313 are performed for each system, there is a possibility that a deviation occurs in the symbol timing of each system. By this digital delay circuit 306 and delay time adjustment circuit 307-3, the symbol timing of the signal of the one-segment part of each system can be matched.

  The segment placement circuit 302 inputs the one-segment signal delayed by the digital delay circuit 306, and performs frequency conversion to a segment to be placed when it is connected to one equivalent baseband signal.

  As described above, according to the terrestrial digital broadcast retransmission apparatus 3 according to the third embodiment, the same effects as those of the first embodiment can be obtained. Further, the frequency error correction circuit 303 can eliminate frequency component errors caused by jitter included in the local frequency when the reception conversion circuit 201 performs frequency conversion, and can prevent inter-carrier interference in the addition circuit 400. .

  Further, the digital delay circuit 306 and the delay time adjustment circuit 307-3 can match the symbol timing of the signal of the one-segment part of each system. As a result, the symbol head positions of the equivalent baseband signals can be aligned, and therefore, when the adder circuit 400 is connected as one equivalent baseband signal, the symbol synchronization timings of all 13 segments can be retransmitted at the same timing. It becomes possible. As a result, in the receiver that receives the retransmission signal from the retransmission apparatus 3, the accuracy of symbol synchronization is improved, and the frequency error correction amount becomes accurate.

  Next, Example 4 will be described. The fourth embodiment eliminates frequency component errors caused by jitter included in the local frequency when the reception conversion circuit 201 performs frequency conversion, prevents inter-carrier interference in the adder circuit 400, and eliminates one-segment of each system. Retransmission is performed in accordance with the symbol timing so that the symbol head position and the SP pattern of the partial signal match.

  FIG. 7 is a block diagram showing the configuration (Example 4) of the digital terrestrial broadcast retransmission apparatus according to the embodiment of the present invention. The retransmission apparatus 4 includes a reception antenna unit 100 (not shown), N tuner units 200, N digital processing units 314, a delay time adjustment circuit 307-4, an addition circuit 400, a retransmission unit 500, and The transmitting antenna unit 600 (not shown) is configured. Since the digital processing unit 314 includes N systems, and each system includes the same circuit, only one system will be described below. The digital processing unit 314 includes an LPF circuit 301, a frequency error correction circuit 303, a symbol synchronization detection circuit 304, an FFT circuit 308, an SP pattern detection circuit 309, a digital delay circuit 306, and a segment arrangement circuit 302. Comparing the retransmission apparatus 3 according to the third embodiment shown in FIG. 6 with the retransmission apparatus 4, both apparatuses include a reception antenna unit 100, a tuner unit 200, an adder circuit 400, a retransmission unit 500, and a transmission antenna unit 600. The digital processing unit 314 of the retransmission apparatus 4 includes an FFT circuit 308 and an SP pattern detection circuit 309 in addition to the configuration of the digital processing unit 313 of the retransmission apparatus 3. The difference is that a delay time adjustment circuit 307-4 having a different configuration from the delay time adjustment circuit 307-3 of the retransmission apparatus 3 is provided. In the following, in FIG. 7, the same reference numerals as those in FIG.

  The symbol synchronization detection circuit 304 receives the one-segment signal extracted by the LPF circuit 301, detects the frequency error amount of the signal of the one-segment portion and the head position of the symbol by guard correlation, and corrects the frequency error amount to the frequency error. The signal is output to the circuit 303, and the symbol head position information is output to the delay time adjustment circuit 307-4. In addition, a timing signal indicating the start of an effective symbol period is generated for the one-segment part signal, and is output to the FFT circuit 308.

  The frequency error correction circuit 303 receives the one-segment signal from the LPF circuit 301, receives the frequency error amount from the symbol synchronization detection circuit 304, corrects the frequency error in the one-seg signal using the frequency error amount, The error-corrected one-segment signal is output to the digital delay circuit 306 and the FFT circuit 308.

  The FFT circuit 308 receives the frequency error corrected one-segment signal from the frequency error correction circuit 303, receives the effective symbol timing signal from the symbol synchronization detection circuit 304, and performs an effective signal in the time-domain one-segment portion by Fourier transform. The symbol signal is converted into a frequency domain signal.

  The SP pattern detection circuit 309 receives the signal of the one-segment part in the frequency domain from the FFT circuit 308 and detects which of the arrangement patterns (all four patterns) of the SP of the ISDB-T system.

  FIG. 8 is a pattern diagram showing the arrangement of SPs. As shown in FIG. 8, there are four SP patterns 1 to 4 in the SP pattern of the ISDB-T system. The SP pattern detection circuit 309 detects any one of the four SP patterns 1 to 4 with respect to the input one-segment signal in the frequency domain.

  The delay time adjustment circuit 307-4 inputs the symbol head position information from the symbol synchronization detection circuit 304 of each system digital processing unit 314-1 to 314-1N, and inputs the SP pattern information from the SP pattern detection circuit 309, respectively. The delay time of each system is calculated with reference to the reception timing of any equivalent baseband signal so that the symbol head positions and SP patterns of all equivalent baseband signals match.

  The digital delay circuit 306 of each system receives the one-segment signal corrected by the frequency error by the frequency error correction circuit 303, inputs the delay time calculated by the delay time adjustment circuit 307-4, and is corrected for the frequency error. Delay the signal by the delay time. Since the tuner processing by the tuner unit 200 and the digital processing by the digital processing unit 314 are performed for each system, there is a possibility that a deviation occurs in the symbol timing of each system. With this digital delay circuit 306 and delay time adjustment circuit 307-4, the symbol timing of the signal of the one-segment part of each system can be adjusted so that the head position of the symbol and the SP pattern match.

  The segment placement circuit 302 inputs the one-segment signal delayed by the digital delay circuit 306, and performs frequency conversion to a segment to be placed when it is connected to one equivalent baseband signal.

  As described above, according to the terrestrial digital broadcast retransmission apparatus 4 according to the fourth embodiment, the same effects as those of the first embodiment can be obtained. Further, the frequency error correction circuit 303 can eliminate frequency component errors caused by jitter included in the local frequency when the reception conversion circuit 201 performs frequency conversion, and can prevent inter-carrier interference in the addition circuit 400. .

  Furthermore, the symbol timing and SP pattern of the signal of the one-segment part of each system can be matched by the digital delay circuit 306 and the delay time adjustment circuit 307-4. As a result, when the adder circuit 400 is connected as one equivalent baseband signal, it is possible to retransmit the 13-segment symbol synchronization timings and the SP patterns. As a result, in the receiving device that receives the retransmission signal from the retransmitting device 4, the accuracy of symbol synchronization is improved, the frequency error correction amount is accurate, and the SP of the adjacent segment when performing equalization processing Can be used.

  Next, Example 5 will be described. The fifth embodiment eliminates frequency component errors caused by jitter included in the local frequency when the reception conversion circuit 201 performs frequency conversion, prevents inter-carrier interference in the adder circuit 400, and eliminates one-segment of each system. This is to retransmit the partial signal in accordance with the start position of the frame.

  FIG. 9 is a block diagram showing the configuration (Example 5) of the terrestrial digital broadcast retransmission apparatus according to the embodiment of the present invention. The retransmission apparatus 5 includes a reception antenna unit 100 (not shown), N tuner units 200, N digital processing units 315, a delay time adjustment circuit 307-5, an addition circuit 400, a retransmission unit 500, and The transmitting antenna unit 600 (not shown) is configured. Since the digital processing unit 315 is composed of N systems, and each system is composed of the same circuit, only one system will be described below. The digital processing unit 315 includes an LPF circuit 301, a frequency error correction circuit 303, a symbol synchronization detection circuit 304, an FFT circuit 308, a frame synchronization detection circuit 310, a digital delay circuit 306, and a segment arrangement circuit 302. When the retransmission apparatus 4 of the fourth embodiment shown in FIG. 7 is compared with the retransmission apparatus 5, both the reception antenna unit 100, the tuner unit 200, the adder circuit 400, the retransmission unit 500, and the transmission antenna unit 600 are both used. However, the digital processing unit 315 of the retransmission apparatus 5 includes a frame synchronization detection circuit 310 instead of the SP pattern detection circuit 309 in the digital processing unit 314 of the retransmission apparatus 4. The retransmission apparatus 5 is different in that it includes a delay time adjustment circuit 307-5 having a configuration different from that of the delay time adjustment circuit 307-4 of the retransmission apparatus 4. In the following, in FIG. 9, the same reference numerals as those in FIG.

  The frame synchronization detection circuit 310 receives the signal of the one-segment part of the frequency domain from the FFT circuit 308, detects the frame head position from the TMCC (Transmission and Multiplexing Configuration Control) signal included in the ISDB-T signal, and demodulates it. To do. Then, the detected frame head position information is output to the delay time adjustment circuit 307-5. Here, since frame information is added to the ISCC-T TMCC signal, the head position of the frame can be detected by monitoring the TMCC signal.

  The delay time adjustment circuit 307-5 receives symbol head position information from the symbol synchronization detection circuit 304 of each digital processing unit 315-1 to 31-N, and receives frame head position information from the frame synchronization detection circuit 310, respectively. The delay time of each system is calculated with reference to the reception timing of any equivalent baseband signal so that the symbol head position and the frame head position of all equivalent baseband signals coincide.

  The digital delay circuit 306 of each system receives the one-segment signal corrected by the frequency error correction circuit 303 and the delay time calculated by the delay time adjustment circuit 307-5 to correct the frequency error. Delay the signal by the delay time. Since the tuner processing by the tuner unit 200 and the digital processing by the digital processing unit 315 are performed for each system, there is a possibility that the frame timing of each system is shifted. By using the digital delay circuit 306 and the delay time adjustment circuit 307-5, the symbol timing of the signal of the one-segment part of each system can be adjusted so that the frame head positions coincide. In this case, when the frame head position matches, the symbol head position and the SP pattern also match.

  The segment placement circuit 302 inputs the one-segment signal delayed by the digital delay circuit 306, and performs frequency conversion to a segment to be placed when it is connected to one equivalent baseband signal.

  As described above, according to the terrestrial digital broadcast re-transmission device 5 according to the fifth embodiment, the same effects as those of the first embodiment can be obtained. Further, the frequency error correction circuit 303 can eliminate frequency component errors caused by jitter included in the local frequency when the reception conversion circuit 201 performs frequency conversion, and can prevent inter-carrier interference in the addition circuit 400. .

  Further, the frame start position of the signal of the one-segment part of each system can be adjusted by the digital delay circuit 306 and the delay time adjustment circuit 307-5. As a result, when the adder circuit 400 is connected as one equivalent baseband signal, the frame synchronization timings of all 13 segments can be aligned, and the symbol synchronization timings and SP patterns can also be retransmitted. As a result, in the receiving device that receives the retransmission signal from the retransmitting device 5, the accuracy of symbol synchronization is improved, the frequency error correction amount is accurate, and the SP of the adjacent segment when performing equalization processing Can be used.

  Next, Example 6 will be described. In the sixth embodiment, a TS signal uniquely generated separately from the terrestrial digital television broadcast is added using the method of the first embodiment and transmitted together with the terrestrial digital television broadcast. That is, the signals of N partial receiving units and M unique TS signals in the received N-wave terrestrial digital broadcasting are connected in one channel (band 6 MHz) and transmitted. N + M ≦ 13 (hereinafter the same).

  FIG. 10 is a block diagram showing the configuration (Example 6) of the terrestrial digital broadcast retransmission apparatus according to the embodiment of the present invention. The retransmission apparatus 6 includes a reception antenna unit 100, N tuner units 200, N digital processing units 311, M modulation units 721, an addition circuit 400, a retransmission unit 500, and a transmission antenna unit 600. Is done. In addition, since the modulation | alteration part 721 is comprised by M system | strain and each system | strain is comprised by the same circuit, only one system | strain is demonstrated below. The modulation unit 721 includes an OFDM modulation circuit 701, an OFDM framing processing circuit 702, an inverse Fourier transform circuit 703, a GI addition circuit 704, and a segment arrangement circuit 705. Comparing the retransmitting apparatus 1 of the first embodiment shown in FIG. 1 with this retransmitting apparatus 6, the receiving antenna unit 100, the tuner unit 200, the digital processing unit 311, the adding circuit 400, and the retransmitting unit 500 are both used. In addition to the configuration of the retransmission apparatus 1, the retransmission apparatus 6 is different in that it further includes M modulation sections 721. In FIG. 10, the same reference numerals as those in FIG. 1 are given to portions common to FIG. 1, and detailed description thereof is omitted.

  When an original TS (eg, MPEG (Moving Picture Experts Group) -TS) signal such as autonomous broadcasting, community broadcasting, commercial, and independent production is input to the modulation unit 721, the OFDM modulation circuit 701 of the modulation unit 721 inputs the original TS signal. An error correction code is added to QPSK (Quadrature Phase Shift Keying) modulation, 16QAM (Quadrature Amplitude Modulation) modulation, 64QAM modulation, and the like, and carrier modulation according to the rate and purpose is performed, and various interleaving processes are performed.

  The OFDM framing processing circuit 702 receives the signal modulated by the OFDM modulation circuit 701, adds a pilot carrier, an AC (Auxiliary Channel), and TMCC to the same arrangement as the partial reception unit of terrestrial digital broadcasting, and performs OFDM framing processing I do.

  The inverse Fourier transform circuit 703 receives the signal subjected to OFDM frame processing by the OFDM frame processing circuit 702 and performs inverse Fourier transform on the carrier data for one symbol of the signal into a time domain signal. The GI addition circuit 704 receives the time-domain signal that has been subjected to inverse Fourier transform by the inverse Fourier transform circuit 703, and performs GI addition according to a preset GI ratio. The segment arrangement circuit 705 inputs the signal to which the GI is added by the GI addition circuit 704 and performs frequency conversion into a segment to be arranged when it is connected to one equivalent baseband signal. The segment arrangement circuit 705 is functionally identical to the segment arrangement circuit 302.

  The adder circuit 400 inputs the equivalent baseband signal of the one-segment part digitally processed by the N-system digital processing unit 311 and inputs the equivalent baseband signal of the original TS signal modulated by the M-system modulation unit 721. Then, these equivalent baseband signals are added and synthesized.

  As described above, according to the terrestrial digital broadcast retransmitting device 6 according to the sixth embodiment, the same effect as that of the first embodiment can be obtained, and a TS signal generated independently from the terrestrial digital television broadcast can be obtained. In addition, it can be transmitted together with digital terrestrial television broadcasting.

  Next, Example 7 will be described. In the seventh embodiment, by using the method of the second embodiment, the signals of N partial receiving units and M unique TS signals in the received N-wave terrestrial digital broadcasting are connected in one channel. To be sent.

  FIG. 11 is a block diagram showing the configuration (Example 7) of the digital terrestrial broadcast retransmission apparatus according to the embodiment of the present invention. The retransmission apparatus 7 includes a reception antenna unit 100, N tuner units 200, N digital processing units 312, M modulation units 721, an addition circuit 400, a retransmission unit 500, and a transmission antenna unit 600. Is done. When the retransmission apparatus 2 of the second embodiment shown in FIG. 2 is compared with the retransmission apparatus 7, the difference is that the retransmission apparatus 7 further includes a modulation unit 721 in addition to the configuration of the retransmission apparatus 2. To do. Further, when comparing the retransmission apparatus 6 of the sixth embodiment shown in FIG. 10 and the retransmission apparatus 7, the retransmission apparatus 7 is different from the digital processing section 311 of the retransmission apparatus 6 in the digital processing section 312. It differs in that it has.

  The receiving antenna unit 100, the tuner unit 200, the digital processing unit 312, the adding circuit 400, the retransmitting unit 500, and the transmitting antenna unit 600 are the same as those of the retransmitting apparatus 2 in the second embodiment, and thus description thereof is omitted. Further, since the modulation unit 721 is the same as that of the retransmission apparatus 6 in the sixth embodiment, description thereof is omitted.

  As described above, according to the terrestrial digital broadcast retransmitting apparatus 7 according to the seventh embodiment, the same effect as that of the second embodiment can be obtained, and a TS signal generated independently from the terrestrial digital television broadcast can be obtained. In addition, it can be transmitted together with digital terrestrial television broadcasting.

  Next, Example 8 will be described. In the eighth embodiment, by using the method of the third embodiment, the signals of N partial reception units and M unique TS signals in the received N-wave terrestrial digital broadcasting are connected in one channel. In particular, the signal of the partial receiving section of each system and the symbol timing in the unique TS signal are transmitted together.

  FIG. 12 is a block diagram showing the configuration (Example 8) of the digital terrestrial broadcast retransmission apparatus according to the embodiment of the present invention. The retransmission apparatus 8 includes a reception antenna unit 100, N tuner units 200, N digital processing units 313, M modulation units 723, a delay time adjustment circuit 307-8, an addition circuit 400, and a retransmission unit 500. , And a transmission antenna unit 600. In addition, since the modulation | alteration part 723 is comprised by M system | strain and each system | strain is comprised by the same circuit, only 1 system | strain is demonstrated below. The modulation unit 723 includes an OFDM modulation circuit 701, an OFDM framing processing circuit 702, an inverse Fourier transform circuit 703, a GI addition circuit 704, a digital delay circuit 706, and a segment arrangement circuit 705. Comparing the retransmission apparatus 3 according to the third embodiment shown in FIG. 3 and the retransmission apparatus 8, both the reception antenna unit 100, the tuner unit 200, the digital processing unit 313, the addition circuit 400, and the retransmission unit 500 are both used. However, the retransmission apparatus 8 is different from the delay time adjustment circuit 307-3 of the retransmission apparatus 3 in that the retransmission apparatus 8 includes M modulation sections 723. The difference is that a delay time adjusting circuit 307-8 having the configuration is provided. In the following, in FIG. 12, the same reference numerals as those in FIG. Further, the OFDM modulation circuit 701, the OFDM framing processing circuit 702, and the inverse Fourier transform circuit 703 of the modulation unit 723 are the same as those of the modulation unit 721 of the retransmission apparatus 6 shown in FIG. Omitted.

  The GI addition circuit 704 of the modulation unit 723 receives the time-domain signal that has been subjected to inverse Fourier transform by the inverse Fourier transform circuit 703, and adds GI according to a preset GI ratio. Further, the head position information of the symbol is output to the delay time adjustment circuit 307-8.

  The delay time adjustment circuit 307-8 receives the symbol head position information from the symbol synchronization detection circuit 304 of the digital processing units 313-1 to 31-N of each system, and adds the GI of the modulation units 723-1 to M of each system. The symbol head position information is input from the circuit 704, and the delay time of each system is set so that the symbol head timing of the equivalent baseband signal of each system matches with the reception timing of any equivalent baseband signal as a reference. Is calculated.

  The digital delay circuit 706 of each system in the modulation unit 723 receives the time domain signal to which the GI is added by the GI addition circuit 704, receives the delay time calculated by the delay time adjustment circuit 307-8, and receives the delay time. Delay by minutes.

  The segment arrangement circuit 705 receives the signal delayed by the digital delay circuit 706 and performs frequency conversion into a segment arranged when the signal is connected to one equivalent baseband signal.

  The adder circuit 400 inputs the equivalent baseband signal of the one-segment part digitally processed by the N-system digital processing unit 313 and inputs the equivalent baseband signal of the original TS signal modulated by the M-system modulation unit 723. Then, these equivalent baseband signals are added and synthesized.

  As described above, according to the terrestrial digital broadcast re-transmission device 8 according to the eighth embodiment, the same effect as that of the third embodiment can be obtained, and a TS signal generated independently of the terrestrial digital television broadcast can be obtained. In addition, it can be transmitted together with digital terrestrial television broadcasting.

  Moreover, the symbol timing of the signal of the one-segment part of each system | strain and the original TS signal can be match | combined. As a result, the symbol start positions of the equivalent baseband signals can be made uniform, so that when the adder circuit 400 connects them as one equivalent baseband signal, the symbol synchronization timing can be transmitted at the same timing.

  Next, Example 9 will be described. In the ninth embodiment, by using the method of the fourth embodiment, the signals of the N partial receiving units and the M unique TS signals in the received N-wave terrestrial digital broadcasting are connected in one channel. In particular, the signal of the partial receiving unit of each system and the symbol timing and SP pattern in the unique TS signal are transmitted together.

  FIG. 13 is a block diagram showing the configuration (Example 9) of the digital terrestrial broadcast retransmission apparatus according to the embodiment of the present invention. The retransmission apparatus 9 includes a reception antenna unit 100, N tuner units 200, N digital processing units 314, M modulation units 723, a delay time adjustment circuit 307-9, an addition circuit 400, and a retransmission unit 500. , And a transmission antenna unit 600. In addition, since the modulation | alteration part 723 is comprised by M system | strain and each system | strain is comprised by the same circuit, only 1 system | strain is demonstrated below. Comparing the retransmission apparatus 4 according to the fourth embodiment shown in FIG. 4 with the retransmission apparatus 9, both the reception antenna unit 100, the tuner unit 200, the digital processing unit 314, the addition circuit 400, and the retransmission unit 500 are both used. However, the retransmission apparatus 9 is different from the delay time adjustment circuit 307-4 of the retransmission apparatus 4 in that the retransmission apparatus 9 includes M modulation sections 723. The difference is that a delay time adjusting circuit 307-9 having the configuration is provided. Further, when comparing the retransmission apparatus 8 according to the eighth embodiment shown in FIG. 12 and the retransmission apparatus 9, the retransmission apparatus 9 includes the digital processing unit 313 and the delay time adjustment circuit 307-8 of the retransmission apparatus 8. Is different in that a digital processing unit 314 and a delay time adjustment circuit 307-9 having different configurations are provided. In FIG. 13, the same reference numerals as those in FIG. 4 are given to portions common to FIG. 4, and detailed description thereof will be omitted. Further, the OFDM modulation circuit 701, the OFDM framing processing circuit 702, and the inverse Fourier transform circuit 703 of the modulation unit 723 are the same as those of the modulation unit 723 of the retransmission apparatus 8 shown in FIG. Omitted.

  The GI addition circuit 704 of the modulation unit 723 receives the time-domain signal that has been subjected to inverse Fourier transform by the inverse Fourier transform circuit 703, and adds GI according to a preset GI ratio. Also, the symbol head position information and the SP pattern information are output to the delay time adjustment circuit 307-9.

  The delay time adjustment circuit 307-9 receives the symbol head position information and the SP pattern information from the digital processing units 313-1 to 31-N of each system, respectively, and the GI addition circuit 704 of the modulation units 723-1 to M of each system. The symbol head position information and the SP pattern information are respectively input from the reception timing of any equivalent baseband signal, so that the symbol head timing and SP pattern of the equivalent baseband signal of each system match. Calculate the delay time of each system.

  The digital delay circuit 706 of each system in the modulation unit 723 receives the time domain signal to which the GI is added by the GI addition circuit 704, receives the delay time calculated by the delay time adjustment circuit 307-9, and receives the delay time. Delay by minutes.

  The segment arrangement circuit 705 receives the signal delayed by the digital delay circuit 706 and performs frequency conversion into a segment arranged when the signal is connected to one equivalent baseband signal.

  The adder circuit 400 inputs the equivalent baseband signal of the one-segment part digitally processed by the N-system digital processing unit 314 and inputs the equivalent baseband signal of the original TS signal modulated by the M-system modulation unit 723. Then, these equivalent baseband signals are added and synthesized.

  As described above, according to the terrestrial digital broadcast retransmitting device 9 according to the ninth embodiment, the same effect as that of the fourth embodiment can be obtained, and a TS signal generated independently from the terrestrial digital television broadcast can be obtained. In addition, it can be transmitted together with digital terrestrial television broadcasting.

  In addition, the symbol timing and SP pattern of the one-segment signal of each system and the unique TS signal can be matched. As a result, the symbol head position and SP pattern of each equivalent baseband signal can be aligned, so that when the adder circuit 400 is connected as one equivalent baseband signal, the timing of symbol synchronization is aligned and the SP pattern is aligned and transmitted. It becomes possible to do.

  Next, Example 10 will be described. The tenth embodiment uses the method of the fifth embodiment to connect N partial reception unit signals and M unique TS signals in the received N-wave digital terrestrial broadcasting into one channel. In particular, the transmission is performed by combining the signal of the partial receiving unit of each system and the frame head position in the unique TS signal.

  FIG. 14 is a block diagram showing the configuration (Example 10) of the digital terrestrial broadcast retransmission apparatus according to the embodiment of the present invention. The retransmission apparatus 10 includes a reception antenna unit 100, N tuner units 200, N digital processing units 315, M modulation units 723, a delay time adjustment circuit 307-10, an addition circuit 400, and a retransmission unit 500. , And a transmission antenna unit 600. In addition, since the modulation | alteration part 723 is comprised by M system | strain and each system | strain is comprised by the same circuit, only 1 system | strain is demonstrated below. Comparing the retransmission apparatus 5 according to the fifth embodiment shown in FIG. 5 and the retransmission apparatus 10, both apparatuses include the reception antenna unit 100, the tuner unit 200, the digital processing unit 315, the addition circuit 400, and the retransmission unit 500. However, the retransmission apparatus 9 is different from the delay time adjustment circuit 307-5 of the retransmission apparatus 5 in that the retransmission apparatus 9 includes M modulation sections 723. The difference is that a delay time adjusting circuit 307-10 having a configuration is provided. 13 is compared with the retransmission apparatus 10 of the ninth embodiment shown in FIG. 13, the retransmission apparatus 10 includes the digital processing unit 314 and the delay time adjustment circuit 307-9 of the retransmission apparatus 9. Is different in that a digital processing unit 315 and a delay time adjustment circuit 307-10 having different configurations are provided. In FIG. 14, the same reference numerals as those in FIG. 5 are given to portions common to FIG. 5, and detailed description thereof will be omitted. Further, the OFDM modulation circuit 701, the OFDM framing processing circuit 702, and the inverse Fourier transform circuit 703 of the modulation unit 723 are the same as those of the modulation unit 723 of the retransmission apparatus 9 shown in FIG. Omitted.

  The GI addition circuit 704 of the modulation unit 723 receives the time-domain signal that has been subjected to inverse Fourier transform by the inverse Fourier transform circuit 703, and adds GI according to a preset GI ratio. Further, the head position information of the frame is output to the delay time adjustment circuit 307-10.

  The delay time adjustment circuit 307-10 receives the head position information of the frame from the digital processing units 313-1 to 31-N of each system, and the head of the frame from the GI addition circuit 704 of the modulation units 723-1 to M of each system. Each position information is input, and the delay time of each system is calculated so that the frame head timing of the equivalent baseband signal of each system matches with the reception timing of any equivalent baseband signal as a reference.

  The digital delay circuit 706 of each system in the modulation unit 723 receives the time domain signal to which the GI is added by the GI addition circuit 704, receives the delay time calculated by the delay time adjustment circuit 307-10, and receives the delay time. Delay by minutes.

  The segment arrangement circuit 705 receives the signal delayed by the digital delay circuit 706 and performs frequency conversion into a segment arranged when the signal is connected to one equivalent baseband signal.

  The adder circuit 400 receives the equivalent baseband signal of the one-segment part digitally processed by the N digital processing units 315 and the equivalent baseband signal of the original TS signal modulated by the M modulation unit 723. Then, these equivalent baseband signals are added and synthesized.

  As described above, according to the terrestrial digital broadcast retransmitting apparatus 10 according to the tenth embodiment, the same effect as that of the fifth embodiment can be obtained, and a TS signal generated independently of the terrestrial digital television broadcast can be obtained. In addition, it can be transmitted together with digital terrestrial television broadcasting.

  In addition, it is possible to match the frame head position of the signal of the one-segment part of each system and the unique TS signal. As a result, the frame start positions of the equivalent baseband signals can be aligned. Therefore, when the adder circuit 400 is connected as one equivalent baseband signal, the frame synchronization timing is aligned, and the symbol synchronization timing and SP pattern are also adjusted. It is possible to re-send the data.

  The present invention has been described with reference to the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the technical idea thereof. For example, in the above-described embodiment, the receiving antenna unit 100 is configured by one antenna. However, the receiving antenna unit 100 is not necessarily limited to one, and may be configured by a plurality of antennas. In this case, each tuner unit 200 inputs digital terrestrial broadcasting received by any one of a plurality of antennas.

  In the above embodiment, the reception conversion circuit 201 of the tuner unit 200 converts the input signal to the intermediate frequency, passes the SAW filter, and then converts the frequency again to the low frequency as a reception method using the intermediate frequency. However, the present invention is not limited to this. For example, the Low-IF (low intermediate frequency) method that directly converts the input signal to a low intermediate frequency signal of about 0.5 to 1.0 MHz, the input signal is once converted to a high frequency (for example, 2 GHz) and passed through the SAW filter. Then, a double conversion method for converting to a low frequency (for example, 1 MHz) or a direct conversion method for directly converting an input signal into an equivalent baseband signal may be used. Refer to “Supervision by Mitsutoshi Hatori,“ 1Seg Broadcast Textbook ”, Impress R & D Co., Ltd.” for details on the reception method using the intermediate frequency.

  In the above embodiment, terrestrial digital broadcasting is targeted, but it can also be applied to terrestrial digital audio broadcasting.

It is a block diagram which shows the structure (Example 1) of the re-transmission apparatus of the terrestrial digital broadcasting by embodiment of this invention. It is a figure which shows the structure and number of a segment of an ISDB-T system. It is a figure which shows the structural example of a receiving channel and a transmission channel. It is a block diagram which shows the structure (Example 2) of the re-transmission apparatus of the terrestrial digital broadcasting by embodiment of this invention. It is a figure explaining the process of the GI replacement circuit of FIG. It is a block diagram which shows the structure (Example 3) of the re-transmission apparatus of the terrestrial digital broadcasting by embodiment of this invention. It is a block diagram which shows the structure (Example 4) of the re-transmission apparatus of the terrestrial digital broadcasting by embodiment of this invention. It is a pattern diagram which shows the arrangement | sequence of SP. It is a block diagram which shows the structure (Example 5) of the re-transmission apparatus of the terrestrial digital broadcasting by embodiment of this invention. It is a block diagram which shows the structure (Example 6) of the re-transmission apparatus of the terrestrial digital broadcasting by embodiment of this invention. It is a block diagram which shows the structure (Example 7) of the re-transmission apparatus of the terrestrial digital broadcasting by embodiment of this invention. It is a block diagram which shows the structure (Example 8) of the re-transmission apparatus of the terrestrial digital broadcasting by embodiment of this invention. It is a block diagram which shows the structure (Example 9) of the re-transmission apparatus of the terrestrial digital broadcasting by embodiment of this invention. It is a block diagram which shows the structure (Example 10) of the re-transmission apparatus of the terrestrial digital broadcasting by embodiment of this invention.

Explanation of symbols

1 to 10 Retransmission device 100 Reception antenna unit 200 Tuner unit 201 Reception conversion circuit 202 AD conversion circuit 203 Orthogonal demodulation circuit 301 LPF circuit 302, 705 Segment arrangement circuit 303 Frequency error correction circuit 304 Symbol synchronization detection circuit 305 GI replacement circuit 306 , 706 Digital delay circuit 307 Delay time adjustment circuit 308 FFT circuit 309 SP pattern detection circuit 310 Frame synchronization detection circuit 311 to 315 Digital processing unit 400 Addition circuit 500 Retransmission unit 501 Orthogonal modulation circuit 502 DA conversion circuit 503 Transmission conversion circuit 600 Transmission Antenna unit 701 OFDM modulation circuit 702 OFDM frame processing circuit 703 Inverse Fourier transform circuit 704 GI addition circuit 721, 723 Modulation unit

Claims (3)

Digital terrestrial broadcasts that receive multiple terrestrial digital broadcasts composed of multiple segments, extract one segment from each of these terrestrial digital broadcast waves, concatenate these extracted segments, and retransmit them as terrestrial digital broadcast waves. In the retransmission device:
A plurality of tuner units, a plurality of digital processing units respectively corresponding to the tuner unit, an addition unit, and a retransmission unit,
The tuner section is
Receiving conversion means for selecting one broadcast wave of the plurality of received terrestrial digital broadcast waves and converting an RF band signal of the broadcast wave into an IF band signal;
AD conversion means for converting the IF signal converted by the reception conversion means into a digital IF signal;
Quadrature demodulation means for performing quadrature demodulation on the digital IF signal converted by the AD conversion means and outputting an equivalent baseband signal;
The digital processing unit
Filter means for extracting one segment from the equivalent baseband signal output by the orthogonal demodulation means of the tuner section;
Symbol synchronization detection means for detecting symbol timing and frequency error amount for symbol synchronization including symbol head position information for the equivalent baseband signal of one segment extracted by the filter means;
A frequency error correction means for correcting a frequency error using an equivalent baseband signal of one segment extracted by the filter means and a frequency error amount detected by the symbol synchronization detection means;
One symbol length is extracted from the equivalent baseband signal by using the equivalent baseband signal of one segment whose frequency error is corrected by the frequency error correction means and the symbol timing detected by the symbol synchronization detection means. When the positions of half of the guard interval length from both ends of one symbol length are the first and second positions, and the positions of the guard interval length from both ends are the third and fourth positions, the first Guard interval changing means for changing a signal between the second position and the third position and a signal between the second position and the fourth position as a new guard interval;
Segment placement means for frequency-converting the equivalent baseband signal of one segment whose guard interval has been changed by the guard interval changing means within a predetermined bandwidth so as to connect a plurality of segments;
The adding unit is
Means for adding and synthesizing the equivalent baseband signals of the respective segments frequency-converted by the segment placement means of the plurality of digital processing units;
The retransmission unit
Quadrature modulation means for performing quadrature modulation on the equivalent baseband signal added and synthesized by the adder and outputting a digital IF signal;
DA conversion means for converting the digital IF signal output by the quadrature modulation means into an analog IF signal;
A transmission conversion means for converting the analog IF signal converted by the DA conversion means into an RF band signal for re-transmission as a terrestrial digital broadcast wave, and amplifying the converted signal; Transmitter device. The re-transmission apparatus according to claim 1 ,
Furthermore, a plurality of modulation units are provided,
The modulator is
OFDM modulation means for inputting an original TS signal and performing OFDM modulation;
OFDM framing means for applying OFDM framing to the signal modulated by the OFDM modulation means;
Inverse Fourier transform means for converting a signal in the OFDM domain by the OFDM framing means to a signal in the time domain from a signal in the frequency domain;
Guard interval adding means for adding a guard interval to the signal in the time domain converted by the inverse Fourier transform means;
Segment placement means for frequency-converting the signal to which the guard interval is added by the guard interval addition means (equivalent baseband signal of the unique TS signal) within a predetermined bandwidth so as to connect a plurality of segments;
The adding unit is
The equivalent baseband signal of each segment frequency-converted by the segment arrangement means of the plurality of digital processing units, and the equivalent baseband signal of each unique TS signal frequency-converted by the segment arrangement means of the plurality of modulation units A retransmission apparatus comprising means for adding and combining signals. The re-transmission apparatus according to claim 1 or 2 ,
The re-transmission apparatus characterized in that one segment extracted by the filter means of the digital processing unit is a segment of a partial reception unit for mobile / mobile broadcasting or a segment of terrestrial digital audio broadcasting.

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