JP3796899B2 - Transmission / reception method, transmission method, reception method, and reception apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
This invention is a sending and receiving process as a radio wave of a plurality of different channels can be received at the same time, transmission method, a receiving method and a receiving apparatus.
[0002]
[Prior art]
Currently, satellite broadcasting, in which radio waves transmitted from broadcasting stations are received via communication satellites or broadcasting satellites, is becoming popular. In such satellite broadcasting, audio and video signals are digitized into data streams. This data stream is divided and packed into packets. A sequence of packets is called a transport stream. The transport stream is modulated in a predetermined frequency band and transmitted to a communication satellite or a broadcast satellite (hereinafter collectively referred to as “satellite”).
[0003]
A plurality of repeaters called transponders are mounted on the satellite. Each transponder covers a different frequency band. Accordingly, a single satellite can simultaneously relay a plurality of broadcasts having different frequency bands. The above-mentioned transmission radio wave is relayed by a transponder having a corresponding frequency band and received by a receiver.
[0004]
In receiving satellite broadcasts, an IRD (Integrated Receiver Decoder) is used to achieve conditional access to the broadcasts. This IRD is composed of a tuner that specifies a receiving transponder, a demodulator, a descrambler that unscrambles, a demultiplexer that specifies a packet to be separated, an image decoder, an audio decoder, and the like. Control supply.
[0005]
[Problems to be solved by the invention]
Conventionally, when two broadcasts relayed by one satellite and transmitted in different frequency bands are simultaneously received, two tuners are used to demodulate broadcast radio waves in the two different frequency bands. There was a problem that it was necessary to provide.
[0006]
Accordingly, an object of the present invention is to provide different such sending and receiving method can receive simultaneously on one tuner airwaves of a frequency band, transmitting method, a receiving method and a receiving device.
[0007]
[Means for Solving the Problems]
The present invention, in order to solve the problems described above, in the transmission method for simultaneously transmitting and modulating the carriers of different frequencies from each other by a plurality of data streams, each of the plurality of data streams at predetermined time intervals simultaneously supplied A step of compressing the time axis in units of delimiters and time intervals, a step of generating a delimiter signal indicating each delimited position of the plurality of data streams, and a plurality of data streams obtained by the compression step a retransmission step of repeating the corresponding output within a predetermined time interval units, a modulation step of modulating a carrier of different frequencies at the output corresponding to each of the plurality of data streams obtained by the retransmission step, delimiting signal Sending the delimiter signal obtained by the step of generating A transmission method and a sending step of sending an output corresponding to each of the plurality of data streams obtained by modulating the steps at the same time.
[0008]
In order to solve the above-described problem, the present invention modulates carriers of different frequencies with a plurality of data streams and transmits them simultaneously, receives and demodulates the transmitted signals, and restores the plurality of data streams. In the transmission / reception method, a compression step of dividing each of a plurality of data streams supplied simultaneously at a predetermined time interval and compressing the time axis in units of time intervals, and a break indicating each divided position of the plurality of data streams steps and, a retransmission of repeating an output corresponding to each within a predetermined time interval units of the plurality of data streams more obtained compression step, a plurality of data streams obtained by the step of retransmitting of generating a signal step modulation for modulating the different frequencies of the carrier at the output corresponding to each of the , Transmits the delimiter signal obtained by the step of generating a delimiting signal, and transmitting step of transmitting an output corresponding to each time of the plurality of data streams obtained by steps of modulation, it is transmitted by the transmission step Receive the signal transmitted in the carrier switching step and the transmission step in which the carrier of the frequency corresponding to the carrier of a different frequency is cyclically switched in synchronization with the received signal delimiter signal and the transmission step. demodulates the received signal based on the carrier obtained in step a carrier switch, and the step of intermittently obtained Ru demodulates the output of the different data streams of the plurality of data streams, intermittently by steps of demodulating the resulting output in synchronization with the carrier switch to the plurality of data streams A step of output switching that switches cyclically to a plurality of output destinations that response, a transmitting and receiving method characterized by comprising the elongation step of each extension time axis of the plurality of output obtained by the step of switching.
The present invention also relates to a receiving method for modulating a plurality of data streams with different frequency carriers and receiving and demodulating simultaneously transmitted signals to restore the plurality of data streams. Each of the streams is divided at a predetermined time interval, and the output corresponding to each of the plurality of data streams compressed in time axis in the time interval unit is repeated within the predetermined time interval unit, and each of the obtained plurality of data streams is repeated. At the same time, outputs corresponding to each of a plurality of data streams obtained by modulating carriers of different frequencies are transmitted at the same time, and a delimiter signal indicating a delimited position of each of the plurality of data streams is transmitted. Receive the signal transmitted by the transmitter, and synchronize with the delimiter signal of the received signal A carrier switching step for cyclically switching carriers of frequencies corresponding to carriers of different frequencies and a signal transmitted by the transmitter are received, and a received signal is demodulated based on the carrier obtained by the carrier switching step. A step of demodulating intermittently obtaining outputs of different data streams of the plurality of data streams, and a plurality of outputs corresponding to the plurality of data streams in synchronization with the carrier switching The output switching step of cyclically switching to the output destination and the expansion step of extending each of the plurality of outputs obtained by the switching step on the time axis is a receiving method.
Also, the present invention provides a receiving apparatus that modulates carriers of different frequencies with a plurality of data streams, receives and demodulates signals transmitted at the same time, and restores the plurality of data streams. Each of the streams is divided at a predetermined time interval, and the output corresponding to each of the plurality of data streams compressed in time axis in the time interval unit is repeated within the predetermined time interval unit, and each of the obtained plurality of data streams is repeated. At the same time, outputs corresponding to each of a plurality of data streams obtained by modulating carriers of different frequencies are transmitted at the same time, and a delimiter signal indicating a delimited position of each of the plurality of data streams is transmitted. Receives the signal transmitted by the transmitting device and synchronizes with the delimiter signal of the received signal Carrier switching means for cyclically switching carriers of frequencies corresponding to different frequency carriers, and a signal transmitted by the transmission device are received, and a received signal is demodulated based on the carrier obtained by the carrier switching means. Te, demodulating means for obtaining an output of the different data streams of the plurality of data streams intermittently, a plurality of output destinations corresponding to the plurality of data stream by intermittently obtained output synchronized with the carrier switching by the demodulation means An output switching means for cyclically switching to each other and an expansion means for extending each of a plurality of outputs obtained by the switching means with respect to the time axis.
[0009]
As described above, according to the present invention, each of a plurality of data streams is divided into predetermined time intervals, time axis compressed in a predetermined time interval unit, and the compressed data is repeated in a predetermined time interval unit. Each of a plurality of data streams is transmitted at a different carrier frequency. At the time of reception, the carrier frequency at the time of demodulation is switched based on a predetermined time interval of the received signal, and the demodulated output is switched cyclically for each different carrier frequency. Therefore, a plurality of channels having different carrier frequencies can be received simultaneously by a receiving apparatus having one tuner.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described. 1 and 2 show an example of a configuration of a transmission / reception system according to this embodiment. In transmitting apparatus 1 shown in FIG. 1, are signals of a plurality of channels modulated with different frequencies of the carrier with respect to each other with the plurality of data. These multi-channel signals are simultaneously transmitted to the communication path 30. These transmitted signals are received in parallel by the receiving device 2 shown in FIG. 2, and an output for each channel is obtained.
[0011]
In FIG. 1, a plurality of data streams (referred to as data streams P, Q, and R) are supplied as a baseband signal to the transmission apparatus 1. These data streams are separated at predetermined time intervals as shown in FIG. 3A. Each divided section is referred to as a segment slot. That is, the segment slot is switched at this predetermined time interval. The data stream P will be described. The data stream P is divided into segment slots, and data 1, data 2, data 3,... Supplied.
[0012]
In the compression circuit 10a, the supplied data stream P is compressed in the time axis direction by a predetermined method for each segment slot. As shown in FIG. 3B, since the data stream P is compressed for each segment slot, a blank portion is generated in the time axis direction in each segment slot. In this example, the data of each segment slot is compressed to 1/6 with respect to the time axis. The compression rate is not limited to 1/6, and other values can be selected. The output of the compression circuit 10a is supplied to the coding / retransmission circuit 11a.
[0013]
The coding / retransmission circuit 11a includes a coding unit and a retransmission unit. The supplied compressed data is first encoded in the coding unit. For this encoding, for example, MPEG (Moving Picture Experts Group) 2 system is used. The compressed data encoded by the coding unit is supplied to the retransmission unit, is repeated a predetermined number of times for each segment slot, and is output from the coding / retransmission circuit 11a. FIG. 3C schematically shows this output signal. Thus, the compressed data corresponding to each segment slot is repeated. From the transmission side, this means that the same compressed data is retransmitted multiple times. For example, as shown in FIG. 3C, the compressed data 1 obtained by compressing the data 1 is repeated in the segment slot designated as data 1 in FIG. 3A. The number of repetitions is preferably determined in accordance with the compression rate of the compression circuit 10a. In this example in which the compression ratio is 1/6, the number of repetitions is six.
[0014]
Hereinafter, a section between the compressed data is referred to as a compression slot. The division of the compression slot corresponds to the division of the segment slot in the signal source from the viewpoint of data.
[0015]
The output of the coding / retransmission circuit 11a is supplied to the modulation circuit 12a. The modulation circuit 11a, modulates the carrier frequency fc ₁ in the supplied data, and outputs. The output of the modulation circuit 11a is a signal of the channel Ch1. The signal of the channel Ch1 is supplied to the multiplexer (MUX) 13.
[0016]
On the other hand, the data streams Q and R are processed in the same manner as the data stream P. That is, as shown in FIG. 4A, the data stream Q is divided into segment slots and supplied to the compression circuit 10b. The output (FIG. 4B) of the compression circuit 10b is supplied to the coding / retransmission circuit 11b, encoded by a predetermined method, and the compressed data is repeated for each segment slot. That is, as shown in FIG. 4A, data A, B, C,... Is time-compressed and repeated for each segment slot, and the compressed data corresponding to each segment slot is repeated as shown in FIG. Are repeatedly arranged to form a compression slot. The output of the coding / retransmission circuit 11b is supplied to a modulation circuit 12b for modulating a carrier frequency fc _2. The compressed data modulated by the modulation circuit 12b is converted to a channel Ch2 signal and supplied to the multiplexer 13.
[0017]
The processing for the data stream R is the same as that for the streams P and Q described above. As shown in FIG. 5A, the data stream R is made into data a, b, c,... For each segment slot, and is made into data as shown in FIG. 5B by the compression circuit 10c, and the coding / retransmission circuit 11c. The compressed data is repeated to form a compressed slot as shown in FIG. 5C. The output of the coding / retransmission circuit 11c is supplied to the modulation circuit 12c, modulates a carrier of frequency fc _3, it is a signal of the channel Ch3 is supplied to the multiplexer 13.
[0018]
Note that the encoding in the coding / retransmission circuits 11a, 11b, and 1c is not limited to the same method. For example, the circuits 11a and 11b can perform encoding using MPEG2 and MPEG1, respectively, and the circuit 11c can perform no encoding. This encoding information is supplied to the multiplexer 13 although its path is omitted in FIG.
[0019]
Although not shown, the multiplexer 13 has a transmission circuit, and the signals of the channels Ch1, Ch2, and Ch3 respectively supplied from the modulation circuits 12a, 12b, and 12c are transmitted at the respective carrier frequencies by the transmission circuit. , Transmitted to the communication path 30. It is preferable that the signals of each channel are synchronized with each other in the segment slots because the processing on the receiving side is simplified.
[0020]
When transmitting, if a predetermined marker, for example, a predetermined pulse signal or a non-signal state signal (level 0 signal for a predetermined period, etc.) is added corresponding to the switching position of the compression slot, the receiving side Is preferable because it makes it easier to detect switching of compression slots. In addition, at the time of transmission, encoding information by the coding / retransmission circuits 11a, 11b, and 11c is added to the corresponding signals, so that various encoding methods can be supported on the receiving side. preferable.
[0021]
The communication path 30 is, for example, via a communication satellite or a broadcast satellite, and transmitted signals are transmitted by transponders corresponding to the respective carrier frequencies. Of course, it is possible to transmit on different channels of the same transponder. Further, the communication path 30 may be a terrestrial wave, and a wired one is also applicable.
[0022]
The signal transmitted via the communication path 30 is received by the receiving device 2 shown in FIG. When the signal is transmitted by radio waves, it is received by an antenna (not shown). Further, when transmitted by wire, it is received by a modem or a predetermined interface (not shown).
[0023]
The received signal is supplied to the demodulation circuit 21 and is also supplied to the slot detection circuit 20. The slot detection circuit 20 detects the switching of the compression slot from the received signal. This compression slot switching position corresponds to a break for each compression slot. This detection result is supplied to the channel changer 23. A carrier having a frequency fc_var is supplied from the channel changer 23 to the demodulation circuit 21. The frequency fc_var is cyclically switched to the frequencies fc ₁ , fc ₂ , and fc ₃ every time the compression slot is switched based on the detection result of the slot detection circuit 20.
[0024]
As an example of the detection method by the slot detection circuit 20, the slot detection circuit 20 has a simple tuner whose tuning frequency is fixed at a frequency fc ₁ corresponding to, for example, the channel Ch1, and is added to the supplied signal. The marker indicating the switching of the compression slot is detected.
[0025]
The demodulating circuit 21 has a tuner unit that receives signals with a predetermined tuning frequency and a demodulating unit that demodulates received signals (not shown), and receives and demodulates signals. The demodulation circuit 21 performs demodulation using the carrier (carrier frequency fc_var) supplied from the channel changer 23. As a result, in the demodulation circuit 21, the carrier frequency is cyclically switched for each compression slot, and reception and demodulation are performed in units of compression slots for each channel Ch1, Ch2, and Ch3.
[0026]
Actually, since a certain amount of time is required for the circuit to be stabilized as the carrier frequency is switched, a signal is lost. Therefore, the signals of the channels Ch1, Ch2, and Ch3 are intermittently received in order in units of compression slots. For example, compressed slots indicated by circles in FIGS. 3C, 4C, and 5C are received. Each received signal is demodulated and output.
[0027]
FIG. 6 schematically shows the output of the demodulation circuit 21. As shown in the figure, compressed data 1, blank, compressed data A, blank, compressed data a, blank, compressed data 2, blank, compressed data B,..., So that each channel Ch1, Ch2, and Ch3 Are output from the demodulation circuit 21 intermittently in order in units of compression slots.
[0028]
The output of the demodulation circuit 21 is supplied to the multipurpose decoder 22. The slot detection circuit 20 described above also detects encoded information added to the received signal. This encoded information is supplied to the multipurpose decoder 22 via the channel changer 23. The multipurpose decoder 22 has various decoding processes, and decodes the output of the demodulation circuit 21 by a corresponding method based on the supplied encoded information.
[0029]
The output of the multipurpose decoder 22 is supplied to the demultiplexer 24. The demultiplexer 24 is configured as a switch circuit having three output terminals 24a, 24b, and 24c, for example, as shown in FIG. This switch circuit is switched based on the detection result of the switching of the compression slot detected by the slot detection circuit 20 and supplied via the channel changer 23 described above. In this demultiplexer 24, the compression slots distributed to the respective channels Ch1, Ch2, and Ch3 are supplied to time axis expansion / output processing circuits 25a, 25b, and 25c, respectively.
[0030]
The time axis extension / output processing circuits 25a, 25b, and 25c include a time axis extension unit and an output processing unit. In the time axis expansion unit, time axis expansion corresponding to the time axis compression performed by the compression circuits 10a, 10b, and 10c of the transmission apparatus 1 is performed. The signals of the channels Ch1, Ch2, and Ch3 are expanded in time axis in the circuits 25a, 25b, and 25c, respectively, and returned to the baseband signal. These signals are subjected to predetermined signal processing and output as channel Ch1 output, channel Ch2 output, and channel Ch3 output, respectively.
[0031]
As described above, by using the present invention, a single tuner can receive a large number of channels having different carrier frequencies in parallel. Therefore, for example, a so-called picture-in-picture (hereinafter referred to as “PinP”) in which a sub-screen which is another video area can be displayed in the main screen and two screens of the main screen and the sub-screen are displayed in one screen. Technology) or a so-called picture-and-picture (hereinafter abbreviated as “P & P”) in which a single screen is divided into left and right to be divided into a main screen and a sub-screen to display different images. The present invention can be applied to this.
[0032]
Conventionally, in a television receiver to which this PinP is applied, for example, two tuners are provided, and videos of different channels are projected on the main screen and the sub-screen. By using such a television receiver, the user displays the channel that he / she currently selects on the main screen, and displays other channels on the sub screen, and simultaneously watches the main screen and the sub screen. be able to. Also in a television receiver to which P & P is applied, conventionally, for example, two tuners are provided, and images of different channels are projected on these main screen and sub-screen.
[0033]
A television receiver having one tuner by broadcasting a television broadcast based on the configuration of the transmission device 1 according to this embodiment and applying the configuration of the reception device 2 to the television receiver. Thus, the above-described PinP and P & P functions can be realized.
[0034]
Further, in the transmission apparatus 1, the data stream P is different from each of the channels Ch1, Ch2, and Ch3, such as audio data, the data stream Q is video data, and the data stream R is binary data such as program data. Different types of data can be transmitted. The transmitted data is separated and output by the demultiplexer 24. The audio data of the channel Ch1 is subjected to predetermined processing by the time axis expansion / output processing circuit 25a and is reproduced by, for example, a speaker. Similarly, the video data of channel Ch2 is supplied to a display device or the like, and a video is projected. The binary data of channel Ch3 is written in a recording medium such as a hard disk.
[0035]
In the above description, the data stream is time-axis compressed for each segment slot and retransmitted in order, but this is not limited to this example. In the transmission of a data stream that does not have real-time characteristics and the time series is not particularly problematic, for example, the transmission of program data, time axis compression and expansion are not necessarily essential. Further, in this case, an operation for rearranging data at the output stage is possible. Therefore, even if several segments are collected together and retransmitted in one repetition cycle, data can be restored on the receiving side.
[0036]
In the above description, the coding / retransmission circuit 11a is arranged in the subsequent stage of the compression circuit 10a in the transmission apparatus 1 and the encoding is performed after the time axis compression. However, this is not limited to this example. . For example, in the data stream P, the coding / retransmission circuit 11a is separated into the coding circuit 11a ′ and the retransmission circuit 11a ″, the compression circuit 10a is provided at the subsequent stage of the coding circuit 11a ′, and the retransmission circuit 11a ″ is provided at the subsequent stage. It may be. The data stream P is supplied to the coding circuit 11a ′ and is first encoded.
[0037]
In this case, the configuration is changed correspondingly in the receiving apparatus 2, and the time axis expansion / output processing circuit 25 a is separated into the time axis expansion circuit 25 a ′ and the output processing circuit 25 ″, and instead of the multipurpose decoder 22. A time axis expansion circuit 25a ′ is arranged, and the multipurpose decoder 22 is connected to the output terminal 24a of the demultiplexer 24, and the output of the decoder 22 is supplied to the output processing circuit 25 ″.
[0038]
【The invention's effect】
As described above, according to the present invention, in the transmission apparatus, the data stream is time-axis compressed for each segment slot at each of a plurality of carrier frequencies, and the same data is repeatedly retransmitted. In the receiving apparatus 2, the receiving channel is switched corresponding to the segment slot that is time-axis compressed and transmitted. Therefore, there is an effect that a single tuner can receive a plurality of channels having different carrier frequencies in parallel.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating an example of a configuration of a transmission device according to an embodiment.
FIG. 2 is a block diagram showing an example of a configuration of a receiving device according to the embodiment.
FIG. 3 is a schematic diagram schematically illustrating an example of data handled by a transmission device and a reception device.
FIG. 4 is a schematic diagram schematically illustrating an example of data handled by a transmission device and a reception device.
FIG. 5 is a schematic diagram schematically illustrating an example of data handled by a transmission device and a reception device.
FIG. 6 is a schematic diagram schematically showing an output of a demodulation circuit.
[Explanation of symbols]
10a, 10b, 10c ... compression circuit, 11a, 11b, 11c ... coding / retransmission circuit, 12a, 12b, 12c ... modulation circuit, 13 ... multiplexer, 20 ... slot detection circuit, 21 ... Demodulation circuit, 22 ... Multipurpose decoder, 23 ... Channel changer

Claims (4)

In a transmission / reception method for modulating carriers of different frequencies with a plurality of data streams and transmitting them simultaneously, receiving and demodulating the transmitted signals, and restoring the plurality of data streams,
A compression step of dividing each of a plurality of data streams supplied simultaneously at a predetermined time interval and compressing the time axis in units of the time interval;
Generating a delimiter signal indicating a delimited position of each of the plurality of data streams;
A retransmission step of repeating an output corresponding to each of the more obtained the plurality of data streams in step of the compression within the predetermined time interval units,
A modulation step of modulating a carrier frequency different from each other in the output corresponding to each of the plurality of data streams obtained by the step of the retransmission,
Transmitting the delimiter signal obtained by the step of generating the delimiter signal, and simultaneously transmitting an output corresponding to each of the plurality of data streams obtained by the modulation step;
A carrier switching step of receiving the transmitted signal in the transmission step and cyclically switching carriers of frequencies corresponding to the carriers of different frequencies in synchronization with the delimiter signal of the received signal; ,
Receiving the transmitted signal in the transmitting step, demodulating the received signal based on the carrier obtained in the carrier switching step , and outputting different data streams of the plurality of data streams a step of intermittently obtained Ru demodulate,
An output switching step of cyclically switching the output obtained intermittently by the demodulation step to a plurality of output destinations corresponding to the plurality of data streams in synchronization with the carrier switching;
A transmission / reception method comprising: a decompression step of decompressing each of a plurality of outputs obtained by the switching step . In a transmission method in which carriers of different frequencies are modulated with a plurality of data streams and transmitted simultaneously,
A compression step of dividing each of a plurality of data streams supplied simultaneously at a predetermined time interval and compressing the time axis in units of the time interval;
Generating a delimiter signal indicating a delimited position of each of the plurality of data streams;
A retransmission step of repeating an output corresponding to each of the plurality of data streams obtained by the compression step within the predetermined time interval unit;
A modulation step of modulating a carrier frequency different from each other in the output corresponding to each of the plurality of data streams obtained by the step of the retransmission,
It transmits the delimiter signal obtained by the step of generating the delimiting signal, that a transmitting step of transmitting an output corresponding to each of the plurality of data streams obtained by the step of the modulation at the same time A characteristic transmission method . In a receiving method for modulating a plurality of data streams with different frequencies and receiving and demodulating simultaneously transmitted signals, and restoring the plurality of data streams,
Each of the plurality of data streams supplied at the same time is divided at a predetermined time interval, and the output corresponding to each of the plurality of data streams obtained by time axis compression in the time interval unit is repeated within the predetermined time interval unit, Simultaneously transmitting outputs corresponding to the plurality of data streams obtained by modulating carriers of different frequencies with outputs corresponding to the plurality of data streams obtained, and The frequency corresponding to the carrier having the different frequency in synchronization with the delimiter signal of the received signal is received by the transmitting unit that transmits the delimiter signal indicating each demarcated position of the ream A carrier switching step for cyclically switching between carriers,
The transmission unit receives the transmitted signal, demodulates the received signal based on the carrier obtained by the carrier switching step, and outputs different data streams of the plurality of data streams. A step of demodulating intermittently;
An output switching step of cyclically switching the output obtained intermittently by the demodulation step to a plurality of output destinations corresponding to the plurality of data streams in synchronization with the carrier switching;
An expansion step for extending each of the plurality of outputs obtained by the switching step with respect to a time axis;
A receiving method comprising: In a receiving apparatus that modulates carriers of different frequencies with a plurality of data streams, receives and demodulates signals transmitted simultaneously, and restores the plurality of data streams,
Each of the plurality of data streams supplied at the same time is divided at a predetermined time interval, and the output corresponding to each of the plurality of data streams obtained by time axis compression in the time interval unit is repeated within the predetermined time interval unit, Simultaneously transmitting outputs corresponding to each of the plurality of data streams obtained by modulating carriers having different frequencies with outputs corresponding to the obtained data streams, and the plurality of data streams. Receiving a signal transmitted by a transmitting device that transmits a delimiter signal indicating each demarcated position of the signal, and synchronizing with the delimiter signal of the received signal and having a frequency corresponding to the carrier of the different frequency Carrier switching means for cyclically switching carriers;
The transmitting apparatus receives the transmitted signal, demodulates the received signal based on the carrier obtained by the carrier switching means, and intermittently outputs different data streams of the plurality of data streams. Demodulating means to obtain automatically,
Output switching means for cyclically switching the output obtained intermittently by the demodulation means to a plurality of output destinations corresponding to the plurality of data streams in synchronization with the carrier switching;
Elongating means for elongating the time axis of each of the plurality of outputs obtained by the switching means;
A receiving apparatus comprising:

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