JP4697505B2 - Signal processing apparatus and method, and digital broadcast signal distribution system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a signal processing apparatus and method, and a digital broadcast signal distribution system, and more particularly to a signal processing apparatus and method suitable for use in the case of listening to a digital broadcast signal, and a digital broadcast signal distribution system.
[0002]
[Prior art]
In apartments like condominiums, only one parabolic antenna for receiving broadcast signals such as BS (Broadcasting Satellite) broadcasts and CS (Communications Satellite) broadcasts is provided on the rooftop, etc., and the received broadcast signals are distributed to each individual unit. There is something to do (so-called “listening”).
[0003]
FIG. 1 shows an example of the configuration of a conventional system for co-listening to satellite broadcasting. In the system, as shown in FIG. 2, the antenna 2 receives BS broadcast waves of 11.71398 GHz to 12.00950 GHz and CS broadcast waves of 12.250 GHz to 12.7465 GHz (hereinafter referred to as RF (Radio Frequency) signals). To LNB (Low Noise Block) 3. The LNB 3 converts the RF signal supplied from the antenna 2 into an IF (Intermediate Frequency) signal in a frequency band as shown in FIG. 3 and outputs the IF signal to the distributor 5-1. The distributors 5-1 to 5-3 distribute the input IF signal and output it to the subsequent stage. The amplifiers 6-1 to 6-6 amplify the input IF signal and output it to the subsequent stage.
[0004]
For example, the individual dwelling unit 1-1 is distributed with the IF signal distributed by the distributor 5-1, amplified by the amplifier 6-1, distributed by the distributor 5-2, and amplified by the amplifier 6-2. . The IF signal distributed to the individual dwelling unit 1-1 is distributed by the distributor 7-1 and supplied to the BS tuner built-in television receiver (BS TV) 8-1 and the set top box (STB) 9-1. Is done.
[0005]
Similarly, the IF signal in which distribution and amplification are repeated is also distributed to the individual dwelling units 1-2 to 1-4.
[0006]
For example, when the antenna 2 has a popular diameter (35 cm to 40 cm), the C / N (Carrier to Noise ratio) of the IF signal output by the LNB 3 is about 15 dB to 20 dB in fine weather. Further, a device that receives BS digital broadcasting such as the set top box 9-1 requires an IF signal having a C / N of about 9 dB or more in order to stably display an image.
[0007]
[Problems to be solved by the invention]
As described above, since the distribution and amplification are repeated for the IF signals distributed to the individual dwelling units 1-1 to 1-4, the C / N is deteriorated as compared with the stage where the LNB 3 outputs. ing. Further, the C / N of the IF signal also deteriorates due to a reception failure due to weather deterioration such as rainfall. Therefore, there has been a problem that a situation in which the C / N of the IF signal supplied to the set top box 9-1 or the like is deteriorated from a required value and a stable image cannot be displayed may occur.
[0008]
The present invention has been made in view of such a situation, and when the distribution and amplification are repeated with respect to the IF signal corresponding to the broadcast wave, the C / N thereof should not be less than the required value. With the goal.
[0009]
[Means for Solving the Problems]
The signal processing apparatus according to the present invention extracts and demodulates channel signals respectively corresponding to a plurality of transponders constituting a satellite from a digital broadcast signal transmitted via the satellite, so that video and audio of one or more contents can be obtained. Data stream generation means for generating an encoded data stream that has been encoded, and restoration by restoring the channel signal by digitally encoding and modulating the generated encoded data stream and converting it to the same frequency as the channel signal A signal corresponding to a digital broadcast signal by multiplexing a plurality of modulation means respectively corresponding to the transponders and a plurality of restored channel signals output by the plurality of modulation means operating in parallel. Multiplexing means for regenerating the data.
[0010]
The signal processing method of the present invention extracts and demodulates channel signals respectively corresponding to a plurality of transponders constituting the satellite from the digital broadcast signal transmitted via the satellite by the data stream generating means of the modulating means , A data stream generating step for generating an encoded data stream in which video and audio of one or more contents are encoded, and the encoded data stream generated by the restoring means of the modulating means is digitally encoded and modulated; A restoration step for restoring the channel signal by converting to the same frequency as the signal, and a plurality of restored channel signals outputted by the multiplexing means operating in parallel by the multiplexing means are multiplexed. A multiplexing step for regenerating a signal corresponding to a digital broadcast signal; Including.
[0011]
The digital broadcast signal distribution system according to the present invention extracts and demodulates channel signals respectively corresponding to a plurality of transponders constituting the satellite from the digital broadcast signal transmitted through the satellite, thereby obtaining one or more content videos. And a data stream generating means for generating an encoded data stream in which audio is encoded, and the generated encoded data stream is digitally encoded and modulated, converted to the same frequency as the channel signal, and A plurality of modulation means each corresponding to a transponder, and a plurality of restored channel signals output by operating the plurality of modulation means in parallel. A multiplexing method for regenerating a signal corresponding to the digital broadcast signal. And a distributor for distributing the signal corresponding to the digital broadcast signal output from the signal processing device.
[0012]
In the signal processing apparatus and method according to the present invention, channel signals respectively corresponding to a plurality of transponders constituting a satellite are extracted from a digital broadcast signal transmitted via the satellite and demodulated, whereby one or more contents are recorded. An encoded data stream in which video and audio are encoded is generated, the generated encoded data stream is digitally encoded and modulated, converted to the same frequency as the channel signal, and the channel signal is restored. The restored channel signal is overlapped to regenerate a signal corresponding to the digital broadcast signal.
[0013]
In the digital broadcast signal distribution system of the present invention, channel signals respectively corresponding to a plurality of transponders constituting the satellite are extracted from the digital broadcast signal transmitted via the satellite and demodulated, so that one or more contents can be transmitted. An encoded data stream in which video and audio are encoded is generated, the generated encoded data stream is digitally encoded and modulated, converted to the same frequency as the channel signal, and the channel signal is restored. The restored channel signal is overlapped to regenerate a signal corresponding to the digital broadcast signal. Further, a signal corresponding to the digital broadcast signal is distributed.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
A satellite broadcasting common listening system to which the present invention is applied will be described with reference to FIG. This satellite broadcast co-listening system is a system for co-listening to satellite broadcasts, and in particular, suppresses the deterioration of C / N of BS digital broadcasts. This satellite broadcast hearing system is configured by adding a satellite digital broadcast hearing apparatus 21 between the LNB 3 and the distributor 5-1 in the conventional system shown in FIG. The other components are the same as those in the system of FIG.
[0015]
The satellite digital broadcast hearing aid device 21 uses the BS digital signal among the IF signals (1035.98 MHz to 1331.50 MHz corresponding to the BS broadcast shown in FIG. 3 and 1214.322 MHz to 2068.50 MHz corresponding to the CS broadcast) input from the LNB 3. Four channels of IF signals corresponding to broadcast channels CH1, CH3, CH13, and CH15, respectively (the bandwidth of each channel is 34.5 MHz, and the center frequency is 1049.48 MHz, 1087.84 MHz, 1279.64 MHz, or 1318.00 MHz, respectively) The MPEG (Moving Picture Experts Group) 2 transport stream (hereinafter referred to as TS) corresponding to each channel is restored, and the C / N modulated by the restored TS is improved. The IF signal is output to the distributor 5-1.
[0016]
Here, terms such as channel CH1 correspond to each transponder of the broadcasting satellite.
[0017]
FIG. 5 shows an example of the detailed configuration of the satellite digital broadcast common sound apparatus 21. The distributor 31 distributes the IF signal corresponding to the BS broadcast wave input from the LNB 3 to the CH1 remodulator 32, the CH3 remodulator 35, the CH13 remodulator 38, and the CH15 remodulator 41. To do.
[0018]
The front end unit 33 of the CH1 remodulation unit 32 extracts and demodulates the frequency component corresponding to the channel CH1 from the input IF signal, and outputs the TS corresponding to the obtained channel CH1 to the modulation unit 34. The modulation unit 34 modulates the IF signal with the TS input from the front end unit 33 and outputs the IF signal to the multiplexing unit 44.
[0019]
The front end unit 36 of the CH3 remodulation unit 35 extracts and demodulates the frequency component corresponding to the channel CH3 from the input IF signal, and outputs the TS corresponding to the obtained channel CH3 to the modulation unit 37. The modulation unit 37 modulates the IF signal with the TS input from the front end unit 36 and outputs the IF signal to the multiplexing unit 44.
[0020]
The front end unit 39 of the CH13 remodulation unit 38 extracts and demodulates a frequency component corresponding to the channel CH13 from the input IF signal, and outputs the TS corresponding to the obtained channel CH13 to the modulation unit 40. The modulation unit 40 modulates the IF signal with the TS input from the front end unit 39 and outputs the IF signal to the multiplexing unit 44.
[0021]
The front end unit 42 of the CH15 remodulation unit 41 extracts and demodulates the frequency component corresponding to the channel CH15 from the input IF signal, and outputs the TS corresponding to the obtained channel CH15 to the modulation unit 43. The modulation unit 43 modulates the IF signal with the TS input from the front end unit 42 and outputs the IF signal to the multiplexing unit 44.
[0022]
The multiplexing unit 44 includes an IF signal corresponding to the channel CH1 input from the modulation unit 34, an IF signal corresponding to the channel CH3 input from the modulation unit 37, and an IF signal corresponding to the channel CH13 input from the modulation unit 40. The IF signal corresponding to the channel CH15 input from the modulation unit 43 is multiplexed and output to the subsequent distributor 5-1.
[0023]
The control unit 45 controls the drive 46 to read a control program stored in the magnetic disk 47, the optical disk 48, the magneto-optical disk 49, or the semiconductor memory 50, and based on the read control program, the satellite digital The entire broadcast hearing apparatus 21 is controlled.
[0024]
FIG. 6 shows a configuration example of the front end unit 33. The tuner 51 extracts a frequency component corresponding to the channel CH1 from the input IF signal, and outputs the frequency component to the demodulator 52 as baseband signals I and Q. The demodulator 52 performs 8PSK (Phase Shift Keying) demodulation processing on the baseband signals I and Q input from the tuner 51, and then performs inner code decoding processing (Viterbi decoding processing), deinterleaving processing, descrambling processing, Outer code decoding processing (Reed-Solomon decoding processing) is performed, and the TS corresponding to the obtained channel CH 1 is output to the modulation unit 34.
[0025]
The front end portions 36, 39, and 42 are also configured in the same manner as the front end portion 33, and thus description thereof is omitted.
[0026]
FIG. 7 shows a configuration example of the modulation unit 34. The encoder 61 performs an outer encoding process, an energy spreading process, an interleaving process, and an inner encoding process (convolutional code) on the TS corresponding to the channel CH1 input from the demodulator 52 in synchronization with the clock signal CLK of the built-in oscillator. Baseband signals I and Q and the used clock signal CLK are output to the 8PSK modulator 62.
[0027]
The 8PSK modulation unit 62 performs a 8PSK modulation process on the baseband signals I and Q input from the encoder 61 in synchronization with the clock signal CLK input from the encoder 61, and maps them to the phases as shown in FIG. A carrier (1stIF signal) corresponding to CH1 is output to the frequency converter 63.
[0028]
The frequency converter 63 converts the carrier corresponding to the channel CH1 input from the 8PSK modulation unit 62 into an IF signal having a bandwidth of 34.5 MHz with a center frequency of 1049.48 MHz corresponding to the channel CH1 and outputs the IF signal to the multiplexing unit 44.
[0029]
The modulation units 37, 40, and 43 are also configured in the same manner as the modulation unit 34, and thus the description thereof is omitted.
[0030]
Next, the operation of the satellite digital broadcast common sound apparatus 21 will be described with reference to the flowchart of FIG.
[0031]
In step S1, the distributor 31 converts the IF signal corresponding to the BS broadcast wave input from the LNB 3 into a CH1 remodulation unit 32, a CH3 remodulation unit 35, a CH13 remodulation unit 38, and a CH15 remodulation. Distributed to the unit 41.
[0032]
In step S2, the tuner 51 of the front end unit 33 of the CH1 remodulation unit 32 extracts a frequency component corresponding to the channel CH1 from the input IF signal, and outputs the frequency component to the demodulation unit 52 as baseband signals I and Q. .
[0033]
In step S3, the demodulation unit 52 performs 8PSK demodulation processing on the baseband signals I and Q input from the tuner 51, performs inner code decoding processing in step S4, performs deinterleaving processing in step S5, In S6, descrambling is performed, and in step S7, outer code decoding is performed, and the TS corresponding to the obtained channel CH1 is output to the modulation unit 34.
[0034]
In step S8, the encoder 61 of the modulation unit 34 performs an outer coding process on the TS corresponding to the channel CH1 input from the demodulation unit 52 in synchronization with the clock signal CLK of the built-in oscillator. A spread process is performed, an interleave process is performed in step S 10, and an inner encoding process is performed in step S 11, and the obtained baseband signals I and Q are output to the 8PSK modulator 62.
[0035]
In step S <b> 12, the 8PSK modulation unit 62 performs 8PSK modulation processing on the baseband signals I and Q input from the encoder 61, and outputs the carrier (1st IF signal) corresponding to the obtained channel CH <b> 1 to the frequency converter 63. In step S13, the frequency converter 63 converts the carrier corresponding to the channel CH1 input from the 8PSK modulation unit 62 into an IF signal having a center frequency of 1049.48 MHz and a bandwidth of 34.5 MHz corresponding to the channel CH1. Output to.
[0036]
In steps S2 to S13, the CH3 remodulation unit 35, the CH13 remodulation unit 38, and the 15CH1 remodulation unit 41 also execute the same processing as the processing of the CH1 remodulation unit 32 described above. . Therefore, IF signals corresponding to the channels CH1, CH3, CH13, and CH15 are input to the multiplexing unit 44.
[0037]
In step S14, the multiplexing unit 44 multiplexes the IF signals respectively corresponding to the channels CH1, CH3, CH13, and CH15, and outputs the multiplexed signals to the subsequent distributor 5-1.
[0038]
As described above, in the satellite digital broadcast hearing apparatus 21, among the IF signals input from the LNB 3, four channels of IF signals respectively corresponding to the BS digital broadcast channels CH1, CH3, CH13, and CH15 are received. The TS corresponding to each channel is demodulated and the IF signal is modulated again by the restored TS, so that the C / N of the IF signal can be greatly improved.
[0039]
For example, the C / N of the IF signal that the LNB 3 supplies to the satellite digital broadcast common sound device 21 in a clear sky is 15 dB to 18 dB, but the IF supplied from the satellite digital broadcast common sound device 21 to the distributor 5-1 The C / N of the signal is about 50 dB.
[0040]
Therefore, it is possible to supply an IF signal that does not fall below the C / N (about 9 dB) required by the STB 9-1 or the like even if the distribution and amplification are repeated after the distributor 5-1.
[0041]
The present invention is not limited to BS digital broadcasting, but can be applied to all types of digital broadcasting in addition to CS digital broadcasting and terrestrial digital broadcasting.
[0042]
The series of processes described above can be executed by hardware, but can also be executed by software. When a series of processing is executed by software, a program constituting the software may execute various functions by installing a computer incorporated in dedicated hardware or various programs. For example, it is installed from a recording medium in a general-purpose personal computer or the like.
[0043]
As shown in FIG. 5, the recording medium is distributed to provide a program to the user separately from the computer, and includes a magnetic disk 47 (including a floppy disk) on which the program is recorded, an optical disk 48 (CD- ROM (Compact Disc-Read Only Memory), DVD (Digital Versatile Disc) is included), magneto-optical disc 49 (MD (Mini Disc) is included), or semiconductor memory 50, etc. It is configured by a ROM, a hard disk or the like on which a program is recorded, which is provided to the user in a state of being pre-installed in the computer.
[0044]
In the present specification, the step of describing the program recorded in the recording medium is not limited to the processing performed in time series according to the described order, but is not necessarily performed in time series, either in parallel or individually. The process to be executed is also included.
[0045]
Further, in this specification, the system represents the entire apparatus constituted by a plurality of apparatuses.
[0046]
【The invention's effect】
As described above, according to the signal processing apparatus and method of the present invention, distributable, when repeated amplification, it is possible to produce a digital broadcast signal does not become less than or equal to the value that C / N is required .
[0047]
Further, according to the digital broadcast signal distribution system of the present invention, it is possible to supply the digital broadcast signal of not high C / N.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration example of a conventional system for listening to satellite broadcasting.
FIG. 2 is a diagram illustrating a frequency band of an RF signal.
FIG. 3 is a diagram illustrating a frequency band of an IF signal.
FIG. 4 is a block diagram showing a configuration example of a satellite broadcast common listening system to which the present invention is applied.
FIG. 5 is a block diagram showing a detailed configuration example of the satellite broadcast common sound apparatus 21;
6 is a block diagram illustrating a configuration example of a front end unit 33. FIG.
7 is a block diagram illustrating a configuration example of a modulation unit 34. FIG.
FIG. 8 is a diagram for explaining 8PSK modulation processing;
FIG. 9 is a flowchart for explaining the operation of the satellite broadcast common sound apparatus 21;
[Explanation of symbols]
31 Distributor, 32 CH1 Remodulation Unit, 33 Front End Unit, 34 Modulation Unit, 35 CH3 Remodulation Unit, 36 Front End Unit, 37 Modulation Unit, 38 CH13 Remodulation Unit, 39 Front End Unit, 40 Modulation Part, 41 CH15 remodulation part, 42 front end part, 43 modulation part, 44 multiplexing part, 45 control part, 46 drive, 47 magnetic disk, 48 optical disk, 49 magneto-optical disk, 50 semiconductor memory

Claims (3)

Coding in which video and audio of one or more contents are encoded by extracting and demodulating channel signals respectively corresponding to a plurality of transponders constituting the satellite from a digital broadcast signal transmitted via the satellite Data stream generating means for generating a data stream;
A plurality of modulation means each corresponding to the transponder, comprising: a restoration means for digitally coding and modulating the generated encoded data stream, converting the modulated data stream to the same frequency as the channel signal, and restoring the channel signal; When,
Multiplexing means for multiplexing a plurality of restored channel signals output by the plurality of modulation means operating in parallel to regenerate a signal corresponding to the digital broadcast signal. . Coding in which video and audio of one or more contents are encoded by extracting and demodulating channel signals respectively corresponding to a plurality of transponders constituting the satellite from a digital broadcast signal transmitted via the satellite Data stream generating means for generating a data stream;
A plurality of modulation means each corresponding to the transponder, comprising: a restoration means for digitally coding and modulating the generated encoded data stream, converting the modulated data stream to the same frequency as the channel signal, and restoring the channel signal; When,
Multiplexing means for multiplexing a plurality of restored channel signals output by the plurality of modulation means operating in parallel to regenerate a signal corresponding to the digital broadcast signal. In the signal processing method of the apparatus,
By extracting and demodulating channel signals respectively corresponding to a plurality of transponders constituting the satellite from the digital broadcast signal transmitted via the satellite by the data stream generating means of the modulating means , one or more contents A data stream generating step for generating an encoded data stream in which video and audio of
A restoring step of restoring the channel signal by digitally encoding and modulating the generated encoded data stream by the restoration means of the modulation means , converting the modulated data stream to the same frequency as the channel signal;
Multiplexing step of multiplexing the plurality of restored channel signals output by the plurality of modulation units operating in parallel by the multiplexing unit, and regenerating a signal corresponding to the digital broadcast signal And a signal processing method. Coding in which video and audio of one or more contents are encoded by extracting and demodulating channel signals respectively corresponding to a plurality of transponders constituting the satellite from a digital broadcast signal transmitted via the satellite Data stream generating means for generating a data stream;
A plurality of modulation means each corresponding to the transponder, comprising: a restoration means for digitally coding and modulating the generated encoded data stream, converting the modulated data stream to the same frequency as the channel signal, and restoring the channel signal; When,
Multiplexing means for multiplexing a plurality of restored channel signals output by the plurality of modulation means operating in parallel to regenerate a signal corresponding to the digital broadcast signal. When,
And a distributor for distributing the signal corresponding to the digital broadcast signal output from the signal processing device.

Images