JP2000332578A - Receiver for digital broadcast - Google Patents

Abstract

PROBLEM TO BE SOLVED: To search for all channels in a short time by making a channel search according to the priority order given in the order of more number of channels which are previously broadcasted among digital broadcasts digitally and previously modulated by multiple digital modulation systems for one selected channel. SOLUTION: A microcomputer 15 for control controls the whole and a front- end part 13 digitally demodulates >=2 kinds of digital modulated signal; and an MPEG decoding part 14 generates an MPEG image and a channel selecting means 16 selects a desirable channel. An all-channel search means 17 gives priority order to a search for all the channels at the time of presetting and a channel data nonvolatile storage means 18 stores the frequencies of selected channel. A channel selection order determining means 19 gives priority order the channels in the order of digital modulation systems of more broadcast channels among digital broadcasts which are already delivered. Consequently, a correct channel can be selected in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital broadcasting receiver.

[0002]

2. Description of the Related Art A conventional digital broadcast receiver transmits only one digital broadcast modulated by one type of digital modulation method in one broadcast system. It consisted of a front-end unit that could demodulate the system. For this reason, when performing a channel selection search on all channels at the time of presetting, a channel selection is performed in such a manner that a front end unit capable of demodulating one type of digital demodulation method is selected for one channel selection channel.

[0003]

However, when digital broadcasting modulated by two or more types of digital modulation systems is transmitted by one broadcasting system, the digital broadcasting receiver uses two or more types of digital demodulation systems. It is composed of a front end unit that can demodulate. Therefore, when a channel is selected and searched at the time of presetting, it is necessary to select a front end unit capable of demodulating two or more types of digital demodulation methods for one selected channel. The tuning device has a problem that it takes a long time to select a correct channel.

[0004]

In order to solve the above-mentioned problems, a digital broadcast receiver according to the present invention, when performing a channel selection search at the time of presetting, sets two types of channels in advance for one channel selection. Of the digital broadcasts digitally modulated by the above digital modulation method, priorities are assigned in descending order of the number of channels to be broadcast, and a search is performed in that order so that the station can be correctly selected in a short time. It is characterized by doing.

According to the present invention, it is possible to provide a digital broadcasting receiver which can select and search all channels in a short time at the time of presetting in a broadcasting system which may be digitally modulated by two or more types of digital modulation methods.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a broadcast system in which two or more types of digital broadcasts are mixed, when all channels are selected and searched at the time of presetting, one channel is selected. Digital broadcast receivers that can be tuned in a short time by prioritizing the digital modulation schemes with the largest number of broadcast channels among the digital broadcasts that have been broadcast in advance, and searching in that order. This has the effect that all channels can be selected and searched in a short time at the time of presetting.

According to a second aspect of the present invention, there is provided an input terminal for inputting a digitally modulated signal, a front end unit for identifying two or more types of digital broadcasts, digitally demodulating them, and confirming digital demodulation synchronization, and digitally demodulated. MPEG decoder for converting the received signal into image data, a control microcomputer for controlling a digital broadcast receiver, a channel selecting means for selecting a desired channel, and the number of broadcast channels among digital broadcasts broadcasted in advance Channel selection order determining means for assigning the priority of channel selection in the order of the most frequently used digital modulation method, all channel selection search means for assigning a priority and selecting and searching all channels, and a channel for storing frequency data of all channels This is a digital broadcast receiver equipped with nonvolatile data storage means. It has the effect that the tuning can search tunnel.

According to a third aspect of the present invention, there is provided a digital broadcast receiver according to the second aspect, wherein the synchronization confirmation of the front end portion is determined by a control voltage of a voltage controlled crystal oscillator. This has the effect that the channel can be selected and searched in a short time.

According to a fourth aspect of the present invention, there is provided the digital broadcast receiver according to the second aspect, wherein the synchronization confirmation of the front end section is determined based on the bit error rate information of the error correction section. Has the effect that all channels can be selected and searched in a short time at the time of presetting.

According to a fifth aspect of the present invention, there is provided a channel selection order determining means for prioritizing channel selections in the order of shorter synchronization establishment time among two or more types of digital broadcasts broadcast in advance. This is a digital broadcasting receiver, and has the effect of selecting and searching all channels in a short time at the time of presetting.

According to a sixth aspect of the present invention, in the digital broadcast receiver according to the fifth aspect, the synchronization confirmation of the front end portion is determined based on a control voltage of a voltage controlled crystal oscillator. This has the effect that all channels can be selected and searched in a short time at the time of presetting.

According to a seventh aspect of the present invention, there is provided the digital broadcast receiver according to the fifth aspect, wherein the synchronization confirmation of the front end section is determined based on the bit error rate information of the error correction section. Has the effect that all channels can be selected and searched in a short time at the time of presetting.

According to an eighth aspect of the present invention, in a broadcasting system in which two or more types of digital broadcasting are mixed, the broadcasting station transmits channel allocation information of digital broadcasting to a user or stores channel allocation information as an initial value. Every
According to the information, a digital broadcast television receiver capable of selecting a channel in a short time so as to select and search all the channels at the time of presetting has an effect of being able to select and search all channels in a short time at the time of presetting. .

According to a ninth aspect of the present invention, there is provided an input terminal for inputting a digitally modulated signal, a front end unit for identifying two or more types of digital broadcasts, digitally demodulating them, and confirming digital demodulation synchronization, and digitally demodulated. MPEG decoder for converting the received signal into image data, a control microcomputer for controlling a digital broadcast receiver, a channel selecting means for selecting a desired channel, and selecting and searching all channels with priorities. All channel selection search means,
The present invention is a digital broadcasting receiver comprising a channel arrangement information storage means for storing channel arrangement information sent from a broadcast station or as an initial value, and a channel data nonvolatile storage means for storing frequency data of all channels. Has the effect that all channels can be selected and searched in a short time at the time of presetting.

According to a tenth aspect of the present invention, there is provided the digital broadcast receiver according to the ninth aspect, wherein the synchronization confirmation of the front end portion is determined by a control voltage of a voltage controlled crystal oscillator. This has the effect that the channel can be selected and searched in a short time.

According to an eleventh aspect of the present invention, there is provided the digital broadcast receiver according to the ninth aspect, wherein the synchronization confirmation of the front end unit is determined based on the bit error rate information of the error correction unit. Has the effect that all channels can be selected and searched in a short time at the time of presetting.

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1, 3, 4, and 5. FIG.

FIG. 1 is a block diagram of a digital broadcasting receiver. An input terminal 11 to which two or more types of transmitted digitally modulated signals are input, and a digitally demodulated received digitally modulated signal to correct errors in a transmission path. A front end unit 13 for correction, an MPEG decoding unit 14 for generating an MPEG image from the output of the front end unit 13, a control microcomputer 15 for controlling the entire digital broadcast receiver, and a tuning unit 16 for selecting a desired channel. Channel selection means 17 for prioritizing the order of channel selection search of all channels at the time of presetting; channel data non-volatile storage means 18 for storing frequency data of channels for which channel selection has been completed; Channel priority in the digital modulation format with the largest number of broadcast channels It is constituted by the channel selection order determining means 19 to give a position.

FIG. 3 is a detailed block diagram of the front end unit 13. The switch circuits 31 and 35 identify two types of digital modulation signals and switch the demodulation path.
A tuner A32 and a tuner B36 for selecting a desired channel, an AD converter A33 and an AD converter B37 for converting an analog signal into a digital signal,
It is composed of a digital demodulation unit + error correction unit A34 and a digital demodulation unit + error correction unit B38 for digitally demodulating a received digital modulation signal and correcting errors in the transmission path.

FIG. 4 is a detailed block diagram of the tuning tuner A32 and the tuning tuner B36. The block diagram of the tuning tuner A32 or the tuning tuner B36 is shown in FIG. An automatic gain control circuit 41 for controlling the power amount suitable for the system, a tuning filter 42 for extracting a signal of a tuning frequency of a desired channel, a mixer 43, and a phase lock loop (PLL) for oscillating the frequency of the desired channel. ) Synchronous circuit 44
, An intermediate frequency band-pass filter 45, and an automatic gain control control 46.

FIG. 5 shows a digital demodulation unit + error correction unit A3.
4, a digital demodulation unit 51 for performing a digital demodulation operation and outputting a digital demodulation signal for determining whether or not the front end unit 13 operates normally; It comprises an error correction section 52 for correcting a path error, an oscillator 53 for producing a system clock of the digital demodulation section 51, and a voltage-controlled crystal oscillator control means 54 for controlling the oscillator 53.

The operation of the present invention will be described below.

At the time of presetting, the channel selection order is determined in advance by the channel selection order determining means 19 in the order of the digital modulation method having the largest number of broadcast channels among the digital broadcasts being broadcast. For example, the digital modulation method A is
When the number of channels is larger than that of the digital modulation system B, the digital modulation system A is given higher priority, and the information on the channel selection order of all the channels is sent to the all channel search means 18 and the information of all receivable channels is sent. Are sequentially transmitted to the channel selecting means 16. The tuning means 16 receiving the information performs the following operations in order.

The information of the selected channel is transmitted to the channel selecting means 1
6 to the control microcomputer 15. The control microcomputer 15 transmits the frequency information of each channel to the front end unit 13 in order. In the front end section 13, FIG.
As shown in (1), the switch circuit 31 first sets a digital modulation method having a high priority to a system capable of digital demodulation. Assuming that the digital modulation system having a higher priority is the modulation system A, first, the switch circuits 31 and 35 are set to the system on the A side, and in the tuning tuner A, as shown in FIG. A tuning operation is started based on the transmitted frequency information. The digital modulation signal received from the input terminal 11 is controlled by the automatic gain control circuit 41 to a power amount suitable for a digital demodulation system at a subsequent stage.

Thereafter, a signal of a desired frequency of the desired signal is extracted by the tuning filter 42. The extracted desired signal is mixed with the tuning frequency oscillated by the PLL oscillation circuit 44 by the mixer 43 and down-converted into the IF signal band. The down-converted desired signal passes through an intermediate frequency band-pass filter 45, and the desired signal is shaped. And
The signal is A / D-converted by an AD converter A33 and input to a digital demodulation unit + error correction unit A34 at a subsequent stage. If the received signal is of the modulation system A, the voltage-controlled crystal oscillator control means 54 and the oscillator 53 that generate the system clock of the digital demodulation unit operate normally, and the digital demodulation unit 51 performs the digital demodulation correctly. The error in the transmission path is corrected by the error correction unit 52.

When the front end section 13 is operating normally, the digital demodulation section synchronizing signal
At this time, it is determined that the front-end unit 13 has normally completed the operation, and information on the normal completion of the channel selection operation is sent to the control microcomputer 15, whereby the channel selection operation is completed. If the received signal is in a modulation scheme called B instead of A, information that the tuning operation has not been completed is sent from the front end unit 13 to the control microcomputer 15. In this case, the control microcomputer 15 is switched to a system for demodulating another demodulation method B, and the same operation as described above is performed.

When the channel selection operation is completed, a transport stream signal of a desired channel is sent from the front end unit 13 to the MPEG decoding unit 14, and the MPEG decoding unit 14 converts the transport stream signal into an MPEG image and outputs it to the outside.

Such an operation is performed for all the channels, and the correct channel data of each channel is stored in the channel data nonvolatile storage means 18.
When the channel is selected next time, the channel data is selected from the channel data nonvolatile storage means 18.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 1, 3, 4, and 6. FIG. 1, 3, and 4 show the configuration described in the first embodiment.

FIG. 6 shows a digital demodulation unit + error correction unit A3.
4 or a digital demodulation unit + error correction unit B38, a digital demodulation unit 51 for performing a digital demodulation operation, an error correction unit 52 for correcting an error in a transmission path, and an oscillator 53 for generating a system clock of the digital demodulation unit 51 , A voltage-controlled crystal oscillator control means 54 for controlling the oscillator 53 and outputting a control signal of the voltage-controlled crystal oscillator for determining whether the front end unit 13 operates normally.

The operation of the present invention will be described below.

The tuning operation is performed in substantially the same manner as in the first embodiment. However, it is determined that the front-end section 13 has normally operated when the voltage-controlled crystal oscillator control means 54 is operating within an appropriate range. The operation is regarded as an operation, and a tuning operation is performed.

(Embodiment 3) Hereinafter, a third embodiment of the present invention will be described with reference to FIGS. 1, 3, 4, and 7. FIG. 1, 3, and 4 are the same as the configurations described in the first embodiment.

FIG. 7 shows a digital demodulation unit + error correction unit A3.
4 or a digital demodulation unit + error correction unit B38 for performing a digital demodulation operation and a digital demodulation unit 51 for correcting an error in a transmission path and determining whether or not the front end unit 13 operates normally. It comprises an error correction section 52 for outputting bit error rate information, an oscillator 53 for producing a system clock of the digital demodulation section 51, and a voltage-controlled crystal oscillator control means 54 for controlling the oscillator 53.

The operation of the present invention will be described below.

The channel selection operation is performed in substantially the same manner as in the first embodiment. However, it is determined that the front end unit 13 has normally operated when the bit error rate information of the error correction unit indicates zero. A channel selection operation is performed using a method that is regarded as a normal operation.

(Embodiment 4) Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG. 1, FIG. 3, FIG. 4, and FIG. The configuration is the same as in the first embodiment.

The operation of the present invention will be described below.

The channel selection operation is performed in substantially the same manner as in the first embodiment, but the priority of the channel selection order by the channel selection order determination means 19 is changed according to the digital modulation system having a large number of broadcast channels in the digital broadcast being broadcast. A method of prioritizing the tuning in order is performed, and the tuning operation is performed. For example, if the digital modulation method A has a shorter synchronization establishment time than the digital modulation method B, the digital modulation method A is given higher priority,
A tuning operation similar to that of the first embodiment is performed.

(Embodiment 5) Hereinafter, a fifth embodiment of the present invention will be described with reference to FIG. 1, FIG. 3, FIG. 4, and FIG. The configuration is the same as that of the second embodiment.

The operation of the present invention will be described below.

The channel selection operation is substantially the same as that of the fourth embodiment. However, it is determined that the front end unit 13 has normally operated when the voltage control crystal oscillator control means 54 is operating within an appropriate range. The operation is regarded as an operation, and a tuning operation is performed.

(Embodiment 6) Hereinafter, a sixth embodiment of the present invention will be described with reference to FIGS. 1, 3, 4, and 7. FIG. The configuration is the same as that of the third embodiment.

The operation of the present invention will be described below.

A channel selection operation substantially similar to that of the fourth embodiment is performed. However, it is determined that the front end unit 13 has normally operated when the bit error rate of the error correction unit indicates zero. A channel selection operation is performed using a method that is regarded as a normal operation.

(Embodiment 7) Hereinafter, a seventh embodiment of the present invention will be described with reference to FIGS. 2, 3, 4, and 5. FIG.

FIG. 2 is a block diagram of a digital broadcast receiver. An input terminal 11 to which two or more types of transmitted digitally modulated signals are inputted, and a digitally demodulated received digitally modulated signal are subjected to digital demodulation so that errors in a transmission path can be detected. A front end unit 13 for correction, an MPEG decoding unit 14 for generating an MPEG image from the output of the front end unit 13, a control microcomputer 15 for controlling the entire digital broadcast receiver, and a tuning unit 16 for selecting a desired channel. And an all-channel tuning means 17 for prioritizing the order of the tuning search of all channels at the time of presetting; a channel data non-volatile storage means 18 for storing frequency data of a channel whose tuning has been completed; Channel arrangement information storage means 21 for storing the transmitted channel arrangement information
It is constituted by.

FIGS. 3, 4, and 5 have the same configuration as that described in the first embodiment.

The operation of the present invention will be described below.
At the time of presetting, first, the channel arrangement storage means 21 storing information on the digital modulation method of each channel transmitted from the broadcasting station or set as an initial value is transmitted to the control microcomputer 15. Thereafter, the all channel search means 17 transmits information on all receivable channels to the tuning means 16 in order. The tuning means 16 receiving the information performs the following operations in order.

The information of the selected channel is transmitted to the channel selecting means 1
6 to the control microcomputer 15. The control microcomputer 15 transmits the frequency information of each channel to the front end unit 13 in order. At the same time, information of the digital modulation system of each channel is also transmitted. Front end unit 13
Then, as shown in FIG. 3, the switch circuit 31 is first set to a system capable of demodulating the digital modulation method based on the information sent from the control microcomputer 15.

Assuming that the information sent from the control microcomputer 15 is the digital modulation system A, the switch circuits 31 and 35 are set to the system on the A side, and the channel selection tuner A receives the information as shown in FIG. Then, the tuning operation is started based on the frequency information sent from the control microcomputer 15. The digital modulation signal received from the input terminal 11 is controlled by the automatic gain control circuit 41 to a power amount suitable for a digital demodulation system at a subsequent stage.

After that, a signal of a desired frequency of the selected signal is extracted by the tuning filter 42. The extracted desired signal is mixed with the tuning frequency oscillated by the PLL oscillation circuit 44 by the mixer 43 and down-converted into the IF signal band. The down-converted desired signal passes through an intermediate frequency band-pass filter 45, and the desired signal is shaped. And
The signal is A / D-converted by an AD converter A33 and input to a digital demodulation unit + error correction unit A34 at a subsequent stage. Then, the voltage-controlled crystal oscillator control means 54 and the oscillator 53 that generate the system clock of the digital demodulation section operate normally, the digital demodulation section 51 performs the digital demodulation correctly, and the error correction section 52 corrects the error of the transmission path. correct.

When the front end unit 13 is operating normally, the digital demodulation unit synchronizing signal is
At this time, it is determined that the front-end unit 13 has normally completed the operation, and information on the normal completion of the channel selection operation is sent to the control microcomputer 15, whereby the channel selection operation is completed.

When the channel selection operation is completed, a transport stream signal of a desired channel is transmitted from the front end unit 13 to the MPEG decoding unit 14, and is converted into an MPEG image by the MPEG decoding unit 14 and output to the outside.

The above operation is performed for all the channels, and the correct channel data of each channel is stored in the channel data nonvolatile storage means 18.
When the channel is selected next time, the channel data is selected from the channel data nonvolatile storage means 18.

Embodiment 8 Hereinafter, an eighth embodiment of the present invention will be described with reference to FIGS. 2, 3, 4, and 6. FIG. The configuration in FIG. 2 is the same as that described in the seventh embodiment. FIGS. 3, 4, and 6 are the same as those described in the second embodiment.

The operation of the present invention will be described below.

The tuning operation is performed in substantially the same manner as in the seventh embodiment. However, it is determined that the front-end unit 13 has operated normally if the voltage-controlled crystal oscillator control means 54 is operating within an appropriate range. The operation is regarded as an operation, and a tuning operation is performed.

Embodiment 9 Hereinafter, a ninth embodiment of the present invention will be described with reference to FIGS. 2, 3, 4, and 7. FIG. The configuration in FIG. 2 is the same as that described in the seventh embodiment. FIGS. 3, 4, and 7 are the same as those described in the third embodiment.

The operation of the present invention will be described below.

The channel selection operation is performed in substantially the same manner as in the seventh embodiment. However, it is determined that the front end unit 13 has normally operated when the bit error rate information of the error correction unit indicates zero. A channel selection operation is performed using a method that is regarded as a normal operation.

[0062]

As described above, in the digital broadcasting receiver of the present invention, when selecting and searching all channels at the time of presetting, the digital modulation is performed in advance by one or more digital modulation methods for one selected channel. Prioritized digital broadcasts are prioritized in descending order of the number of channels to be broadcast, and channel search is performed in that order. It is very practical.

[Brief description of the drawings]

FIG. 1 is a block diagram of a digital broadcast receiver according to one embodiment of the present invention.

FIG. 2 is a block diagram of a digital broadcast receiver according to one embodiment of the present invention;

FIG. 3 is a block diagram of a front end unit according to an embodiment of the present invention.

FIG. 4 is a block diagram of a tuner for tuning according to an embodiment of the present invention;

FIG. 5 is a block diagram of a digital demodulation unit and an error correction unit according to one embodiment of the present invention.

FIG. 6 is a block diagram of a digital demodulation unit + an error correction unit according to one embodiment of the present invention;

FIG. 7 is a block diagram of a digital demodulation unit + an error correction unit according to one embodiment of the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Input terminal 12 Digital broadcasting receiver 13 Front end unit 14 MPEG decoding unit 15 Control microcomputer 16 Channel selection unit 17 All channel search unit 18 Channel data nonvolatile storage unit 19 Channel selection order determination unit 21 Channel arrangement information storage unit 31 Switch circuit 32 Tuner A for channel selection 33 A / D converter A 34 Digital demodulation unit + error correction unit A 35 Switch circuit 36 Tuner B for channel selection 37 AD converter B 38 Digital demodulation unit + error correction unit B 41 Automatic gain control circuit 42 Station filter 43 Mixer 44 PLL circuit 45 Bandpass filter for intermediate frequency 46 Automatic gain control circuit control 51 Digital demodulation unit 52 Error correction unit 53 Voltage controlled crystal oscillator 54 Voltage controlled crystal oscillator control means

Claims (11)

[Claims] 1. In a broadcasting system in which two or more types of digital broadcasts are mixed, when all channels are selected and searched at the time of presetting, the number of broadcast channels of digital broadcasts broadcast in advance for one selected channel is determined. Prioritize in the order of the most frequently used digital modulation method,
A digital broadcast receiver that can select a station in a short time so that the station is searched in that order. 2. An input terminal for inputting a digital modulation signal, a front end unit for identifying two or more types of digital broadcasts, digitally demodulating them, and confirming digital demodulation synchronization;
MPE for converting digitally demodulated signals into image data
A G decoding unit, a control microcomputer for controlling a digital broadcast receiver, a channel selecting means for selecting a desired channel, and a digital modulation system having a large number of broadcast channels among digital broadcasts previously broadcast. A channel selection order determining unit for assigning station priorities; an all channel tuning search unit for assigning a priority to all channels; and a channel data nonvolatile storage unit for storing frequency data of all channels. Digital broadcast receiver. 3. The digital broadcasting receiver according to claim 2, wherein the synchronization confirmation of said front end unit is determined by a control voltage of a voltage controlled crystal oscillator. 4. The digital broadcast receiver according to claim 2, wherein the synchronization confirmation of said front-end section is determined based on bit error rate information of an error correction section. 5. The digital broadcasting receiver according to claim 2, further comprising a channel selection order determining means for prioritizing channel selection in ascending order of synchronization establishment time among two or more types of digital broadcasts broadcast in advance. 6. The digital broadcast receiver according to claim 5, wherein the confirmation of the synchronization of the front end unit is determined by a control voltage of a voltage controlled crystal oscillator. 7. The digital broadcast receiver according to claim 5, wherein the synchronization confirmation of said front-end unit is determined based on bit error rate information of an error correction unit. 8. In a broadcasting system in which two or more types of digital broadcasts are mixed, a broadcast station transmits digital broadcast channel arrangement information to a user, or stores channel arrangement information as an initial value, and uses the information to perform presetting. A digital broadcast television receiver that can select a channel in a short time so that all channels can be selected and searched. 9. An input terminal for inputting a digital modulation signal, a front end unit for identifying two or more types of digital broadcasts, digitally demodulating them, and confirming digital demodulation synchronization,
MPE for converting digitally demodulated signals into image data
A G decoding unit, a control microcomputer for controlling a digital broadcast receiver, a channel selecting means for selecting a desired channel, and an all-channel selecting search means for selecting and searching all channels with priorities; Digital broadcast receiver comprising channel arrangement information storage means for storing channel arrangement information sent from a broadcast station or as an initial value, and channel data nonvolatile storage means for storing frequency data of all channels 10. The digital broadcast receiver according to claim 9, wherein the confirmation of the synchronization of the front end unit is determined by a control voltage of a voltage controlled crystal oscillator. 11. The digital broadcast receiver according to claim 9, wherein the synchronization confirmation of said front-end unit is determined based on bit error rate information of an error correction unit.