JP4955229B2 - Receiving terminal device and receiving system - Google Patents

Description

  The present invention relates to a receiving terminal apparatus mainly used for receiving digital broadcasts, and more specifically, enables the antenna direction to be accurately adjusted using the receiving terminal apparatus.

An example of a BS digital tuner will be described as a conventional receiving terminal device. First, the received signal is input to the channel selection unit. The channel selection unit amplifies the received signal with an RF amplifier, and then selects a signal in a predetermined frequency range by a filter circuit that selectively passes a predetermined band according to the channel selection channel. The selected received signal is level-adjusted in a variable attenuator whose amount of attenuation is varied by a control signal from an automatic gain control circuit, is input to an amplifying unit at a subsequent stage, is amplified to a predetermined level, and is then input to a mixer circuit .
The signal input to the mixer circuit is converted into a predetermined IF signal by a local oscillator. The IF signal converted by this mixer circuit becomes the IF signal of the channel selected through the narrow band filter means through which only the frequency of the desired channel of the IF signal passes, and this IF signal is IF amplified. After being amplified to a predetermined level in the circuit, it is supplied to a variable attenuator controlled by the automatic gain adjustment circuit, and a predetermined level is output.
Next, the IF signal of the selected channel set to a predetermined level in the variable attenuator is input to the demodulator. The demodulation unit is configured to detect the IF signal selected by the channel selection unit by a quadrature detection circuit to form an I signal and a Q signal, and to further demodulate the I signal and the Q signal by a PSK decoder. Has been.
Further, the tuner is provided with a signal processing unit, in which broadcast data such as a channel number and reception data such as a reception state are collected from the received signal, and each unit is controlled based on this data, For example, a display unit composed of a liquid crystal display device (LCD: Liquid Crystal Display, hereinafter referred to as LCD) or the like is controlled based on data obtained from the channel selection unit or the demodulation unit using a digital value or a display graph. It is configured as follows.
(For example, see Patent Document 1)

JP 2003-283940 A

By the way, since the conventional receiving terminal device can display the channel display and the reception level on the display unit provided in the receiving device, for example, if it is selected to display the reception level, the level display is viewed. However, the antenna direction can be adjusted.
By the way, adjustment of the antenna direction generally requires that the input level of the received signal be known in order to correctly point the antenna in the direction of arrival of the radio wave. In the case of digital broadcasting, not only the input signal but also the signal C / N and bit error rate (hereinafter referred to as BER) are related.
Therefore, using broadcast data including data such as a selected channel obtained in the channel selection unit and the demodulation unit, reception data including data that is a source of input level, C / N, BER, and the like, The display unit is configured to display with a display method corresponding to the received data. However, depending on the loop configuration of the AGC circuit in the channel selection unit and the demodulation unit and the data extraction method, the input level is high. If the antenna direction adjustment is performed in an area where the C / N is in a good state, the change in the received signal caused by moving the antenna is compressed, so that the change in the display displayed on the display unit is a slight variation. It can only be adjusted to the direction where the reception level is the highest or the quality of the received signal is optimal. There have been cases have.
Therefore, in this application, it was made to solve these problems.
An object of the present invention is to provide a receiving terminal device capable of accurately adjusting the direction of an antenna within an input level range.
The object is to provide a receiving terminal device capable of accurately adjusting the direction of the antenna even in a strong electric field region.
Another object is to provide a receiving system including a receiving terminal device capable of accurately adjusting the direction of an antenna in a receiving system for receiving digital broadcasting.

In order to solve the above problems, the invention of claim 1 receives at least a reception signal from an antenna that receives a digital broadcast signal and selects broadcast data (for example, a channel number) of the desired broadcast signal from the received signal. Received data including both of or one of C / N data and bit error rate data, and reception level data as a plurality of types of data indicating the reception status of the received signal in different systems while being demodulated by the station A channel selection / demodulation unit with an automatic gain adjustment circuit configured to output, a display unit for switching a plurality of types of contents, and the broadcast data and the reception data obtained from the channel selection / demodulation unit Is received and processed, and at least the control signals for the channel selection / demodulation unit and the display unit are generated and output from the data obtained thereby. In the receiving terminal apparatus having a signal processing unit configured urchin, a,
On the input side of the channel selection / demodulation unit, there is provided attenuation means that can selectively control whether or not the input signal is attenuated by a predetermined amount by the signal processing unit. Is configured to display, on the display unit, contents selected by the user of the receiving terminal device by operating a predetermined operation target among the contents indicated by the broadcast data and the received data. Further, when the signal processing unit displays the content of the reception level data, which is one of the received data , on the display unit, whether the value of the reception level data is greater than a reference value. by determining whether, if the value of the data of the reception level is determined to be greater than the reference value, the damping means, is passed through the input signal by the predetermined amount attenuation of the reception level data If the value is determined to be smaller than the reference value, the attenuation means, the input signal is passed through without the predetermined amount attenuation, whereas, the said content of the received data other than the data of the reception level When any of the contents of broadcast data is displayed on the display unit, the input signal is allowed to pass through the attenuation unit without being attenuated by the predetermined amount regardless of the value of the reception level data. , Is characterized.

According to a second aspect of the present invention, in the receiving terminal device according to the first aspect, the received data includes, as the plurality of types of data, the C / N data and the bit error rate in addition to the reception level data. It is characterized by including both of the data .
On the other hand, for example, the attenuating means includes an attenuator, a transmission line installed in parallel with the attenuator, and an input RF signal, either the attenuator installed in parallel or the transmission line. And a switching signal generation unit that generates a switching signal for path switching of the selection unit based on a control signal output from the signal processing unit. Can do.

According to a third aspect of the present invention, at least a receiving system for receiving a digital broadcast comprises the receiving terminal device according to the first or second aspect , and the receiving system is configured.

According to the first aspect of the present invention, since it is configured as described above, it is possible to adjust the direction of the antenna for receiving the digital broadcast by receiving predetermined reception data (this book displayed on the display unit provided in the digital tuner). In particular, the present invention can solve the problem in the case of using the reception status display such as numbers and display graphs corresponding to the reception level data) . The problem is that when the predetermined reception data obtained from the received data does not reach the predetermined level before the adjustment of the antenna direction, the reception state display is performed with respect to the change in the reception state due to the adjustment of the antenna direction. However, when the antenna direction is adjusted, the reception state improves, and when the predetermined reception data reaches a predetermined level, the change in the reception state of the reception signal caused by moving the antenna is displayed on the display unit. This is a problem that the received change in the reception status display appears only as a slight fluctuation, and it is difficult to make final fine adjustments.
That is, according to the invention described in claim 1, said display unit, of the received data indicating the reception state, a particularly when selecting display the contents of data of the received level, of the data of the reception level When the value is smaller (lower) than the reference value, the RF signal, which is the received signal from the antenna, passes through without being attenuated by the attenuation means, so that the display level changes as before (the reception level display changes greatly). In addition, when the value of the reception level data is larger (higher) than the reference value, the RF signal is automatically attenuated by a predetermined amount by the attenuation means and passes, and the channel selection is performed. -The received signal input to the demodulator can be lowered, and as a result, the change width of the reception status display displayed on the display unit is as large as when the received signal is low Is the direction adjustment of the antenna can be easily to a final fine fine adjustment.
In addition, if the contents of the reception level data are displayed on the display unit, these operations are automatically performed. Therefore, it is not necessary to perform special settings for the user who performs antenna adjustment. Even with this operation method, the optimum antenna direction can be adjusted.

And the antenna direction can be adjusted quickly and accurately.
Further, among a plurality of types of data included in the received data (data of a plurality of types shown in a different manner to receive status), the data outside the data than the reception level, and data C / N, the bit error rate data However, as described in claim 2 , it is preferable that both C / N data and bit error rate data are used.

According to the invention of claim 3 , at least in the receiving system for receiving digital broadcasting, the receiving system is provided with the receiving terminal device according to claim 1 or 2 .
It is possible to provide a receiving system in which the antenna direction can be easily and accurately adjusted using a digital tuner or a television receiver.

Hereinafter, an example of an embodiment embodying the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a digital tuner. FIG. 2 is a block diagram showing a specific example of the channel selection / demodulation unit constituting the digital tuner of the first embodiment according to the present application.

First, an embodiment of the present application will be described with reference to FIGS. In the embodiment of the present application, a digital tuner for receiving BS digital broadcasting will be described. However, the present invention is not particularly limited to this embodiment, and it goes without saying that a digital tuner for terrestrial digital broadcasting may be used.
Reference numeral 1 denotes a digital tuner. A received signal received by a digital antenna (not shown) and transmitted via a coaxial cable or the like is supplied to the channel selection / demodulation unit 100 of the digital tuner 1. The supplied received signal is amplified to a predetermined level while a predetermined frequency range is selected by the channel selection unit 10 in accordance with the channel selection channel. The received signal in the predetermined frequency range selectively extracted by the channel selection unit 10 is subjected to quadrature two-phase detection by the I / Q quadrature detection unit 20 to form an I signal and a Q signal, and the two-axis signal is Output after being amplified to a predetermined level.
I and Q signals output from the I / Q quadrature detection section 20, the transport stream signal demodulated is input to the PSK decode unit 40 for signal demodulation (hereinafter referred to as TS signal.) The output To do.

In the demultiplexing unit 50, the TS signal is separated for each purpose, and if it is a video / audio TS signal, it is sent to the MPEG decoding unit 52, and the data broadcasting TS signal is sent to the signal processing unit 2.
In the MPEG decoding unit 52, the video / audio is decoded from the TS signal input from the demultiplexing unit 50 and output as a video signal and an audio signal.
The image superimposing unit 55 superimposes information such as the data broadcast processed by the signal processing unit 2 on the video signal.
Further, the signal processing unit 2 performs not only control such as AGC control and channel selection of the channel selection / demodulation unit 100, but also broadcasts included in the received signal from the I / Q quadrature detection unit 20, the PSK decoding unit 40, and the like. It is configured to obtain and process information from data (for example, channel number) and received data (for example, reception level, C / N, bit error rate), and to output such information as a predetermined signal as appropriate. .
Reference numeral 3 denotes a display unit for displaying the broadcast data obtained by each unit and the received data indicating the reception state of the received signal by a control signal from the signal processing unit 2.
The display contents of the display unit 3 are, for example, displayed on the channel of the received signal or displayed on the reception level of the received signal by operating the operation unit 4 provided in the digital tuner 1 or a remote controller (not shown). Or can be selectively switched.

Next, description will be given using a specific configuration example of the channel selection / demodulation unit 100.
The received signal is input to the tuning unit 10. The input received signal is composed of, for example, a capacitor and a coil, and the IF band signal (950 to 2150 MHz) transmitted from the BS · 110 ° CS digital antenna is used as a pass band, and a higher frequency and UHF band than the IF band signal. The signal is input to the selection unit 12 after passing through the filter unit 11 including, for example, a bandpass filter having a lower frequency band as a stop band. The selection unit 12 is configured to selectively output the RF signal that has passed through the filter means 11 via any path of the attenuator 13 and the transmission line 14 installed in parallel to the attenuator 13. For example, the high-frequency relays 12-1 and 12-2 and high-frequency switches using diodes are used. Next, the RF signal output from the selection unit 12 is amplified to a predetermined level in an RF amplifier circuit 15 including, for example, a transistor as a high frequency amplifier.

The level of the amplified received signal is adjusted by the variable attenuator 16. The variable attenuator 16 includes, for example, a high-frequency diode controlled by a control signal from an automatic gain control (Automatic Gain Control: AGC) circuit 6.
In the embodiment of the present application, the level of the received signal is detected based on the I signal and the Q signal input to the PSK decoding unit 40, and the detection signal corresponding to the level of the received signal is detected as the PSK decoding unit 40. By feeding back to the AGC circuit 6, the RF signal level of each part and the IF signal level after detection are optimally adjusted.

The level-adjusted received signal is selectively output as a received signal in a predetermined frequency range in the filter means 17 that can change the frequency range that passes in accordance with the channel selected by the digital tuner 1. The
The filter means 17 is composed of a tunable bandpass filter composed of, for example, a capacitor, a coil, and a PIN diode. The received signal in the predetermined frequency range selected by the filter means 17 is arranged next. Input to the I / Q quadrature detection unit 20.
Reference numeral 18 denotes an RF amplifier circuit, which is appropriately disposed as necessary.

  The I / Q quadrature detection unit 20 includes at least a quadrature detection circuit 21 having mixers 21a and 21b, a broadband 90 ° phase shifter 30, and an oscillator 31 having local oscillators 31a and 31b having different oscillation frequencies. Each oscillation frequency is configured to have a predetermined oscillation frequency by an integrated PLL circuit 35, and has a good frequency characteristic in a wide frequency range of 950 to 2150 MHz as the reception signal. It is configured. The PLL circuit 35 is configured to be controlled by a control signal from the PSK decode unit 40 in the embodiment of the present application.

At least before SL I / Q quadrature detection section 20 in the present embodiment, an example in which the orthogonal detection circuit 21, a wideband 90 ° phase shifter 30, oscillator 31 is configured by an IC integrated on a single chip However, for example, amplifiers 26a and 26b for amplifying the baseband signal after I / Q signal detection shown in the figure to a predetermined level and low-pass filters 27a and 27b for limiting the band of the baseband signal are also combined. An IC chip may be formed.
Further, the PLL circuit 35 for controlling the oscillator 31 and the filter means 17 for receiving a control signal from the PLL circuit 35 and selecting a predetermined frequency range of a channel desired to be received from the received signal are controlled. Alternatively, the channel selection means 33 for controlling the oscillation frequency of the oscillator in accordance with the selection of the channel to be received may also be integrated into an IC chip.

Further, as described above, I and Q signals output from the I / Q quadrature detector 20 is input to the PSK decode unit 40 for signal demodulation is the T S signal is demodulated.

Next, the operation of the selection unit 12 will be described in detail. The selection unit 12 is provided with an attenuator 13 and a transmission line 14 installed in parallel with the attenuator 13. The selection unit 12 passes either the attenuator 13 or the transmission line 14. It is comprised so that selection output may be carried out. The switching control of the selection unit 12 is controlled by a switching signal from a switching signal generation unit 5 composed of a transistor or an operational amplifier. The switching signal generation unit 5 further controls the control signal output from the signal processing unit 2. Is controlled by.
In addition, although the example which provided the selection part 12, the path | route switching part which consists of the attenuator 13 and the transmission line 14 of this application in the input side of the channel selection part 10 was shown, for example, the said channel selection / demodulation part 100 is unitized. If it is, the path switching unit may be configured to be connected to the input of the module , and the arrangement position thereof is not limited to the embodiment.

The signal processing unit 2 compares the predetermined received data in the received data with predetermined reference data set in advance corresponding to the predetermined received data in the signal processing unit 2 to thereby generate the switching signal. A control signal (for example, an L signal and an H signal) for the unit 5 is generated, and the control signal can be selectively output based on the contents displayed on the display unit 2.

  That is, in the first embodiment of the present application, at least the contents corresponding to the predetermined reception data (for example, reception level) are displayed on the display unit 3 (by a display method such as digital display or graph display). If the signal processing unit 2 determines that the predetermined received data is larger than the predetermined reference data when selected using the unit 4 or a remote controller (not shown), the control signal output from the signal processing unit 2 is as described above. The switching signal generator 5 is configured to selectively control the selector 12 so as to be a path passing through the attenuator 13 based on the control signal of the H signal shown in FIG. If the unit 2 determines that the predetermined received data is smaller than the predetermined reference data, the control signal output from the signal processing unit 2 is the low signal control described above. Signal is output, said switching signal generating unit 5 based on this the selection unit 12 is configured to selectively control such that the path through the transmission line 14.

The contents corresponding to data other than the predetermined received data on the display unit 3 (e.g., channel number) when selecting to display, either the predetermined received data is greater than a predetermined reference data, small or, in Regardless, the control signal output from the signal processing unit 2 is always a low signal, and based on this, the switching signal generation unit 5 becomes a path through the transmission line 14 through the selection unit 12. It is configured to perform selection control.
The display unit 3 output from the signal processing unit 2 based on the determination result in the signal processing unit 2 so that the reception level display displayed on the display unit 3 does not become discontinuous due to turning on and off of the attenuator. By appropriately amplifying the control signal, the display may be continuous.
Further, in the above embodiment, in the attenuator 13 and the transmission line 14 and the selector 12 and the switching signal generating unit 5, and constitutes a damping means.

  Next, a specific configuration example of the channel selection / demodulation unit 110 of the second embodiment according to the present application will be described with reference to FIG. In this embodiment, the configuration of the attenuator provided on the input side of the channel selection unit 10 is different, and the other configuration is the same as that of the first embodiment. Therefore, in the following description, the first embodiment is different from the first embodiment. Similar components are given the same reference numerals unless otherwise specified, and detailed descriptions thereof are omitted.

The input received signal is composed of, for example, a capacitor and a coil, and the IF band signal (950 to 2150 MHz) transmitted from the BS · 110 ° CS digital antenna is used as a pass band, and a higher frequency and UHF band than the IF band signal. After passing through the filter means 11 comprising, for example, a bandpass filter having a lower frequency band as a stop band, it is input to the attenuation means. The attenuating means includes a variable attenuator 113 using a PIN diode, for example, and a switching signal generator 115 that generates a control voltage so that the attenuation amount of the variable attenuation register 113 has a binary value of a minimum value and a predetermined attenuation value. And the amount of attenuation of the variable attenuator 113 is switched based on a control signal output from the signal processing unit.
In the embodiment of the present application, the attenuation of the variable attenuator is configured to take a binary value. However, the variable attenuator is stepped and changed to three or more values (for example, 0, 10, 20 dB). You may control.

  That is, in the second embodiment of the present application, at least the content corresponding to the predetermined reception data (for example, reception level) is displayed on the display unit 3 (by a display method such as digital display or graph display). If the signal processing unit 2 determines that the predetermined received data is larger than the predetermined reference data when selected using the unit 4 or a remote controller (not shown), the control signal output from the signal processing unit 2 is as described above. The switching signal generator 115 is configured to selectively control the variable attenuation value 113 so that a predetermined attenuation amount (for example, 20 dB) is obtained based on the control signal of the H signal shown in FIG. If the unit 2 determines that the predetermined received data is smaller than the predetermined reference data, the control signal output from the signal processing unit 2 is Signal control signal is output, the switching signal generator 115 on the basis of which the variable attenuation SL 113, is configured to selectively control such that the minimum attenuation (e.g., 0 dB).

The contents corresponding to data other than the predetermined received data on the display unit 3 (e.g., channel number) when selecting to display, either the predetermined received data is greater than a predetermined reference data, small or, in Regardless, the control signal output from the signal processing unit 2 is always a low signal, and based on this, the switching signal generation unit 115 selects the attenuator 113 so as to have a minimum attenuation (for example, 0 dB). It is configured to control.
The variable attenuation notation 113 and the switching signal generation unit 115 in the second embodiment constitute the attenuation means described in claim 1.

As in the first and second embodiments described above, according to the digital tuner 1 of the present application, when the digital tuner 1 is used to adjust the antenna direction, the reception is performed before the antenna direction is adjusted. When the predetermined reception data obtained from the data does not reach the predetermined level, the reception level display changes greatly with respect to the change of the reception level accompanying the adjustment of the antenna direction, but as the antenna direction is adjusted, When the predetermined data received reception level is increased to reach about a predetermined level, relative to the level change of the received signal caused by moving the antenna, a change in the display unit to the displayed reception level (predetermined reception data), only In response to the problem that it becomes difficult to make fine adjustments in the final display, the display unit 3 has the predetermined value. When the content corresponding to the received data is selected and displayed, and the value of the predetermined received data is lower than the value of the predetermined reference data, the RF signal is placed in the normal state (attenuated by the attenuator of the attenuation unit). The display level of the display unit 3 changes as usual (the reception level display changes greatly), and when the value of the predetermined reception data becomes higher than the value of the predetermined reference data, The RF signal is automatically selected so as to pass through the attenuator, and the received signal input to the channel selection / demodulation unit can be lowered by a predetermined level. The width becomes as large as when the reception level is low, and the antenna direction adjustment can be easily made to the final fine adjustment.
In addition, when a display other than the predetermined received data (for example, bit error rate) is displayed (in other words, when data other than the predetermined received data is acquired / determined), the received signal can be detected as it is. By configuring so that the RF signal is input without going through the attenuator, the quality of the received signal input to the digital tuner can be correct information.

When the digital tuner 1 is used to adjust the direction of the antenna, the signal processing unit 2 outputs at least a predetermined signal of the content displayed on the display unit 3 to output the image. If the video signal is output from the superimposing unit 55, the television receiver connected to the digital tuner 1 can also display a level, so that there is a receiving system capable of optimal antenna direction adjustment while watching the television. Can be provided.
In addition, if the digital tuner is set to the antenna direction adjustment mode, these operations are performed automatically. Therefore, there is no need for the user who performs the antenna adjustment, and the operation method as before is not necessary. Even so, it is possible to provide a receiving terminal device for digital broadcasting capable of optimal antenna direction adjustment.

  In the embodiment of the present application, the reception level is used as a criterion for determination. Specifically, the input level may be detected to determine the strength of the level, and switching control may be performed. It may be configured to perform switching control using a value calculated by a predetermined calculation method using a data such as a bit error rate, C / N, etc. of a received signal obtained from a provided demodulation IC or the like, The present invention is not particularly limited, and the configuration of each part can be changed as appropriate without departing from the spirit of the present invention.

It is a schematic block diagram of a digital tuner. It is a block diagram which shows the specific example of the channel selection / demodulation part which comprises the digital tuner which concerns on 1st Example of this application. It is a block diagram which shows the specific example of the channel selection / demodulation part which comprises the digital tuner which concerns on 2nd Example of this application.

DESCRIPTION OF SYMBOLS 1 ... Digital tuner, 2 ... Signal processing part, 3 ... Display part, 4 ... Operation part, 5 * 115 ... Switching signal production | generation part, 6 ... Automatic gain adjustment circuit (AGC circuit), 10 ... Channel selection part, 11 ... Filter means (Band-pass filter), 12 ... selection unit, 13.113 ... attenuator, 14 ... transmission line, 15 ... RF amplification unit, 16 ... variable attenuator, 17 ... filter means (tunable band-pass filter), 18 ... RF Amplifier, 20 ... I / Q quadrature detection unit, 21 ... Quadrature detection circuit, 21a / 21b ... Mixer, 26a / 26b ... Baseband signal amplifier, 27a / 27b ... Low pass filter, 30 ... Broadband 90 ° phase shifter, 31 ... Oscillator, 31a, 31b ... Local oscillator, 33 ... Channel selection means, 35 ... PLL circuit, 40 ... PSK decoding unit, 100/110 ... Channel selection / demodulation unit

Claims (3)

at least,
In response to receiving a received signal from an antenna that receives a digital broadcast signal, the broadcast data of the desired broadcast signal is selected and demodulated from the received signal, and at the same time, as a plurality of types of data indicating the reception status of the received signal in different ways , A channel selection / demodulation unit with an automatic gain adjustment circuit configured to output reception data including C / N data and / or bit error rate data and reception level data ;
A display for switching between multiple types of content;
Accepts and processes the broadcast data and the received data obtained from the channel selection / demodulation unit, and generates at least control signals for the channel selection / demodulation unit and the display unit from the data obtained thereby. And a signal processing unit configured to output,
In a receiving terminal device comprising:
The input side of the channel selection / demodulation unit is provided with attenuation means that can selectively control whether the input signal is attenuated by a predetermined amount by the signal processing unit,
The signal processor is
Of the contents indicated by the broadcast data and the received data, the contents selected by the user of the receiving terminal device by operating a predetermined operation target are displayed on the display unit,
Furthermore, the signal processing unit
When the content of the reception level data that is one of the reception data is displayed on the display unit, it is determined whether the value of the reception level data is greater than a reference value, and If it is determined that the reception level data value is greater than the reference value, the attenuation means passes the input signal after attenuation by the predetermined amount, and the reception level data value is smaller than the reference value. If it is determined that, the attenuation means allows the input signal to pass through without being attenuated by the predetermined amount, while either the content of the received data other than the data of the reception level or the content of the broadcast data. When the signal is displayed on the display unit, regardless of the value of the reception level data , the attenuation means allows the input signal to pass through without being attenuated by the predetermined amount.
A receiving terminal device. The received data includes both the C / N data and the bit error rate data in addition to the reception level data as the plurality of types of data.
The receiving terminal device according to claim 1. At least a receiving system for receiving digital broadcasting, comprising the receiving terminal device according to claim 1 or 2.

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