JP2008236664A - Transmission apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission apparatus which transmits signals from transmitting-side devices 71, 72 to receiving-side devices 73, 74 which performs efficient transmission even if characteristics of desire/undesire (D/U) at the receiving-side device are deteriorated. <P>SOLUTION: At a receiving-side device, a receiving means receives a signal transmitted from a transmitting-side device, a quality detecting means detects reception quality on the basis of the signal received by the receiving means, and a quality information transmitting means transmits, to the transmitting-side device, the information of the reception quality detected by the quality detecting means. At the transmitting-side device, a quality information receiving means receives the information of the reception quality transmitted from the receiving-side device, a data transmitting means includes a function for transmitting a signal to the receiving-side device, and transmits the signal with a narrowed transmission band when the data transmitting means determines that D/U is low based on the information of the reception quality received by the quality information receiving means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transmission apparatus that transmits a signal from a transmission-side apparatus to a reception-side apparatus, and in particular, efficient transmission even when a D / U (Desire / Undesire) characteristic in the reception-side apparatus deteriorates. The present invention relates to a transmission apparatus that performs

  For example, in a broadcasting system such as digital television, a transmission device that transmits video and audio signals such as a program and its material from a transmission-side device to a reception-side device is used. In such a transmission apparatus, for example, an OFDM (Orthogonal Frequency Division Multiplexing) modulation method often used in mobile transmission is used.

FIG. 4 shows a configuration example of a reception high-frequency unit (RH) provided in the reception-side device of the transmission device.
For convenience of explanation, in FIG. 4, the same reference numerals are given to components that are substantially the same as those shown in FIG. There is no intention to limit it to unnecessary.
Further, the configuration and operation of the reception high-frequency unit shown in FIG. 4 is roughly the same as that shown in FIG. 1 except that it does not have the configuration and operation related to the telephone line 14 shown in FIG. Since it is the same, detailed description is abbreviate | omitted here.

However, in the conventional OFDM modulated wave transmission apparatus as shown in FIG. 4, in order to improve the D / U characteristics, the characteristics depend on the characteristics of the SAW filter 22 of the reception high-frequency section which is the reception HEAD section. However, when D / U became extremely bad, it could not be avoided.
For example, in broadcasting stations, only 2 to 4 channels (CH) for transmitting radio waves are usually given, and there is a strong demand to avoid losing one channel for D / U.

  The present invention has been made in view of such conventional circumstances, and even when a signal is transmitted from a transmission-side device to a reception-side device, even when the D / U characteristics of the reception-side device deteriorate. An object of the present invention is to provide a transmission apparatus capable of performing efficient transmission.

In order to achieve the above object, in the present invention, a transmission apparatus that transmits a signal from a transmission apparatus to a reception apparatus has the following configuration.
In other words, in the receiving device, the receiving means receives the signal transmitted from the transmitting device. The quality detection means detects the reception quality based on the signal received by the reception means. The quality information transmitting means transmits the reception quality information detected by the quality detecting means to the transmitting apparatus.
In the transmission-side apparatus, the quality information receiving means receives the reception quality information transmitted from the reception-side apparatus. The data transmission means has a function of transmitting a signal to the reception-side apparatus, and the D / U is low (bad) based on the reception quality information received by the quality information reception means. If it is determined, the signal is transmitted with the transmission band narrowed.

  Accordingly, when a signal is transmitted from the transmission side device to the reception side device, information on reception quality in the reception side device is notified to the transmission side device, and the transmission side device transmits D based on the reception quality information. When it is determined that / U is low, the transmission band used for signal transmission is narrowed. For example, efficient transmission can be performed even when the D / U characteristics of the receiving device deteriorate. Can do.

Here, the transmission device may be applied to various devices, for example, can be applied to a transmission device in a broadcasting system.
In addition, as communication for transmitting a signal from a transmission-side device to a reception-side device, for example, wireless communication may be used, or wired communication may be used.
In addition, as communication for transmitting reception quality information from a reception-side device to a transmission-side device, for example, wireless communication may be used, or wired communication may be used.

In addition, for example, a data signal may be used as the signal to be referred to when the reception quality is detected based on the signal received from the transmission side device in the reception side device, or A signal may be used.
Various reception quality may be used. For example, a D / U value, a reception electric field value, or the like may be used.

In addition, as a method of determining that the D / U is low based on the reception quality information in the receiving device in the transmitting device, for example, the D / U value is less than or equal to the threshold value set in advance. (Or less than a threshold value), it is possible to use a method for determining that the D / U is low.
In addition, various modes may be used as a mode for controlling the transmission band used for signal transmission in the transmission-side apparatus. For example, control is performed based on preset conditions (contents of control method). Such an embodiment can be used.

In addition, as an example of the content of how to control the transmission band, when OFDM modulation is used, the number of carriers is based on the value of the received electric field in the receiving device and the amount of transmission data in the transmitting device. Further, it is possible to use the content of the control method that changes the setting of the modulation mode. Specifically, when the D / U is poor, the number of carriers is reduced while the modulation mode is changed to a higher transmission rate.
Further, for example, a plurality of ranges are provided for the D / U value, the contents of the control method are set for each range, and the control method contents corresponding to the range to which the D / U value belongs are set. It is also possible to use a mode in which the transmission band is controlled using the.

  As described above, according to the transmission apparatus according to the present invention, when a signal is transmitted from a transmission-side apparatus to a reception-side apparatus, the transmission-side apparatus performs D / D based on the reception quality information in the reception-side apparatus. When U is determined to be low, the transmission band used for signal transmission is narrowed. For example, efficient transmission can be performed even when the D / U characteristics in the receiving apparatus deteriorate. it can.

Embodiments according to the present invention will be described with reference to the drawings.
FIG. 3 shows a configuration example of a transmission apparatus according to an embodiment of the present invention.
The transmission apparatus of this example includes a transmission control unit (TC) 71 and a transmission high-frequency unit (TH) 72 as a transmission-side apparatus, and a reception high-frequency unit (RH) 73 and a reception control unit ( RC) 74, and a micro line 81 and a LAN (Local Area Network) line 82 are provided between the transmission side apparatus and the reception side apparatus.

An example of schematic operation performed in the transmission apparatus of this example is shown.
In the transmission side device, the transmission control unit 71 digitally modulates data to be transmitted by, for example, an OFDM modulation method, and the transmission high-frequency unit 72 transmits the modulated signal to the micro line 81.
In the reception side device, the reception high frequency unit 73 receives a signal from the transmission side device via the micro line 81, and the reception control unit 74 demodulates the reception signal.

  Also, in this example, the reception high-frequency unit 73 acquires reception quality information related to, for example, D / U, and transmits the information from the reception-side device to the transmission control unit 71 via the LAN line 82, thereby performing transmission control. The unit 71 switches the number of carriers used for transmission and the modulation mode based on the information.

This will be described in more detail below.
FIG. 1 shows a configuration example of the reception high-frequency unit (RH) 73 of this example.
The reception high-frequency unit 73 of this example includes a low noise amplifier (LNA) 1, an attenuator (PIN ATT) 2, a local oscillator 3, a mixer (MIX) 4, a low-pass filter (LPF) 5, an amplifier 21 and a SAW unit 6 having a SAW (Surface Acoustic Wave) filter 22, an IF (Intermediate Frequency) unit 7 having an attenuator 23 and an amplifier 24, a detection circuit 8 configured using a diode 31 and a capacitor 32, A detection circuit 9 including a diode 33 and a capacitor 34, a comparator 10, a comparator 41 and a CPU (Central Processing Unit) 11 having a ROM (Read Only Memory) 42, a switch (SW) 12, and a display Vessel 13 , It is equipped with a telephone line (TEL line) 14.

Here, in the SAW unit 6, the amplifier 21 and the SAW filter 22 are connected in series.
In the IF unit 7, the attenuator 23 and the amplifier 24 are connected in series, and a part of the output from the amplifier 24 is fed back to the attenuator 23 so that the attenuation rate of the attenuator 23 is variably controlled.
In each of the detection circuits 8 and 9, diodes 31 and 33 are provided in the signal line, and capacitors 32 and 34 are provided between the output-side points of the diodes 31 and 33 and the ground.

An example of the operation performed in the reception high-frequency unit 73 of this example is shown.
A signal transmitted from the transmission side device via the micro line 81 is received and input to the LNA 1.
The LNA 1 amplifies the input signal and outputs it to the attenuator 2.
The attenuator 2 has an attenuation rate controlled according to the input signal from the comparator 10, attenuates the signal input from the LNA 1, and outputs the attenuated signal to the mixer 4.
The local oscillator 3 oscillates a signal having a predetermined frequency (local signal) and outputs it to the mixer 4.

The mixer 4 multiplies (mixes) the signal input from the attenuator 2 and the signal input from the local oscillator 3 to perform frequency conversion, and outputs the resulting signal to the LPF 5.
The LPF 5 filters the signal input from the mixer 4 and outputs the filtered signal to the SAW unit 6 and the diode 31.

The SAW unit 6 amplifies the signal input from the LPF 5 by the amplifier 21, filters it by the SAW filter 22, and outputs it to the IF unit 7 and the diode 33.
Here, the SAW filter 22 passes the desired signal (Desired signal) included in the received signal to be filtered, and removes the undesired signal (Undesired signal) such as interference included in the received signal without passing it. It has the following characteristics. Note that this characteristic is not always an ideal characteristic in an actual circuit.
The IF unit 7 attenuates the signal input from the SAW unit 6 by the attenuator 23, amplifies the signal by the amplifier 24, and outputs the resultant signal to the reception control unit 74. Here, a part of the output from the amplifier 24 is fed back to control the attenuation rate of the attenuator 23.

The detection circuit 8 configured using the diode 31 detects a signal input from the LPF 5 and outputs a signal of the detection result (in this example, information on the voltage level of the signal input from the LPF 5) to the comparator 10 and Output to the CPU 11. Here, the signal from the LPF 5 includes a desired signal and an undesired signal.
The detection circuit 9 configured using the diode 33 detects the signal input from the SAW unit 6 and detects the detection result signal (in this example, information on the voltage level of the signal input from the SAW unit 6). Is output to the CPU 11. Here, the signal from the SAW unit 6 includes the desired signal (assuming that the undesired signal is ideally removed).

The comparator 10 compares the voltage level input from the detection circuit 8 (diode 31) with a predetermined voltage level that has been set, and a signal representing the comparison result (in this example, a voltage level signal) is attenuator 2. And output to the CPU 11. In the attenuator 2, the attenuation rate is controlled by this signal.
The comparator 41 of the CPU 11 includes a voltage level signal (2) from the detection circuit 9 (diode 33), a voltage level signal (3) from the detection circuit 8 (diode 31), and a voltage level signal from the comparator 10. The signal (4) is input, for example, a value related to the reception quality is calculated based on the information (2), (3), (4) and information such as an arithmetic expression stored in the ROM 42, and the calculation result Is output to the display 13 and the telephone line 14.

Here, in this example, the main channel signal is used as the desired signal, and the adjacent channel signal is used as the undesired signal.
In this example, as a value relating to reception quality, an input reception electric field value (BL value) and a D / U value representing a difference between a desired signal (main channel signal) and an undesired signal (adjacent channel signal) are used. Yes.

  In the reception high-frequency unit of this example, for example, when it is determined that there is an adjacent channel signal, the main channel signal and the adjacent channel signal are obtained from the information (4) of the signal obtained by adding the main channel signal and the adjacent channel signal. The difference information {(3)-(2)} is subtracted, the input received electric field value and the D / U value are calculated, and these calculation results can be displayed.

For example, the switch 12 outputs a signal for switching a value to be displayed among the input received electric field value (BL value) and the D / U value to the CPU 11 in accordance with an operation performed by an operator (person).
The comparator 41 of the CPU 11 calculates a value to be displayed according to the signal input from the switch 12. Information on the calculation result is output to the display 13 and the telephone line 14.
The display 13 displays and outputs information on the value input from the comparator 41 of the CPU 11 (in this example, the input received electric field value (BL value) or D / U value) on a screen or the like.
The telephone line 14 is connected to the reception control unit 74 and receives information on the values (in this example, the input reception electric field value (BL value) and D / U value) input from the comparator 41 of the CPU 11. 74 is transmitted and output.

As described above, the reception high-frequency unit of this example not only uses the input reception electric field value (BL value) and the D / U value for display on the meter, but also transmits data of these values to the reception control unit 74.
The reception control unit 74 transmits the input reception electric field value (BL value) data and the D / U value data received from the reception high-frequency unit 73 to the transmission control unit 71 via the LAN line 82.

FIG. 2 shows a configuration example of the transmission control unit (TC) 71 of this example.
The transmission control unit (TC) 71 of this example includes a data conversion unit 51, a digital modulation board 52, a CPU 53 having a LAN board 61, a carrier number changeover switch 54, and a modulation mode changeover switch 55.

An example of the operation performed in the transmission control unit 71 of this example is shown.
The data conversion unit 51 outputs data to be transmitted to the digital modulation board 52 and outputs information specifying the amount of data to be transmitted to the CPU 53.
The digital modulation board 52 digitally modulates the data input from the data conversion unit 51 by, for example, an OFDM modulation method, and outputs the modulation signal (for example, a 130 MHz signal) to the transmission high frequency unit 72.

Here, in the modulation performed by the digital modulation substrate 52, the number of carriers is switched by a signal from the carrier number switch 54, and the modulation mode is switched by a signal from the modulation mode switch 55.
Specifically, the number of carriers in the OFDM modulation scheme and the modulation mode used for each carrier can be switched.

In this example, as the number of carriers, a mode in which (1/1) times the number of carriers (that is, n) is used with respect to a predetermined number n, and (2/3) times the number (that is, It is possible to switch between a mode using 2n / 3 carriers and a mode using (1/2) times the number of carriers (that is, n / 2).
In this example, as a modulation mode, it is possible to switch between a mode using 16QAM (Quadrature Amplitude Modulation), a mode using 32QAM, and a mode using 64QAM.

The CPU 53 receives and captures information regarding the reception quality transmitted from the reception control unit 74 via the LAN line 82 by the LAN board 61. In this example, input reception electric field value (BL value) data and D / U value data are used as information relating to reception quality.
Further, the CPU 53 inputs information for specifying the amount of data to be transmitted from the data conversion unit 51.
In the CPU 53, for example, a threshold (MIN value) relating to the D / U value is set and stored in advance in the internal memory, and the amount of data to be transmitted and the input received electric field value (BL value) are also stored. Accordingly, conditions for determining the number of carriers to be used and the modulation mode are set and stored.

  Then, the CPU 53 compares the D / U value notified from the reception control unit 74 with the threshold value stored in the internal memory, and the D / U value is equal to or less than the threshold value (or less than the threshold value). That is, if the D / U value is worse than the threshold value, the number of carriers and the modulation mode are reset based on the conditions stored in the internal memory in order to avoid the deterioration of the D / U value. .

The CPU 53 sets the number of carriers by controlling the carrier number changeover switch 54 and sets the modulation mode by controlling the modulation mode changeover switch 55.
The carrier number changeover switch 54 outputs a signal for setting (for example, switching) the number of carriers to the digital modulation board 52 in accordance with the control from the CPU 53.
The modulation mode changeover switch 55 outputs a signal for setting (for example, switching) the modulation mode to the digital modulation board 52 in accordance with control from the CPU 53.

  Here, in this example, the combination of the number of carriers and the modulation mode is switched as the modulation mode setting. Specifically, when the D / U value deteriorates, the number of carriers is reduced and the modulation mode is increased. Generally, in order to improve the D / U value, it is effective to reduce the number of carriers and narrow the transmission band. However, when the modulation mode is increased by reducing the number of carriers, the reception electric field is reduced. Can only be used when expensive. Therefore, in this example, the extent to which the number of carriers is reduced or the modulation mode is increased depends on the capacity of the signal to be transmitted (in this example, the amount of data to be transmitted) and the received electric field (in this example, the input received electric field value). (BL value)) and the condition is set.

Thus, in the transmission apparatus of this example, the reception high-frequency unit 73 sends the D / U value information and the BL value information to the reception control unit 74 via the telephone line 14, and the reception control unit 74 sends the information of these values. The data is sent to the transmission control unit 71 via the LAN line 82.
When the transmitting side (transmitter) determines that the D / U value is bad based on the current D / U value information and the BL value information sent from the receiving side (receiver), This is avoided by reducing the number of OFDM modulated wave carriers in the transmitter, that is, by narrowing the transmission band to reduce the influence of the adjacent channel (CH) and the like. In this case, if the number of carriers is reduced, the amount of data that can be transmitted is reduced. Therefore, the modulation mode needs to be set at a high rate, but the adjustment is made in consideration of the reception electric field. Specifically, control based on the reception electric field and the determination based on the amount of data being transmitted is performed to narrow the transmission band as much as possible and to avoid the deterioration of the D / U value.

  In this example, the transmission control unit 71 superimposes information on the number of carriers and the modulation mode set by the transmission control unit 71 on the transmitted signal (in this example, an OFDM modulated wave). On the receiving side, a mode for automatically setting the number of carriers and the modulation mode (AUTO mode) based on information contained in the received signal is set, so that the setting is automatically changed and reception processing is performed. Do.

  As described above, in the transmission apparatus of this example, when data is transmitted from the transmission side to the reception side by the digital method, if the D / U is poor, it is possible to avoid by narrowing the transmission band of its own channel. Do. The determination that the D / U is bad is made by sending the D / U value detected on the receiving side to the transmitting side. On the transmission side, when it is determined that the D / U value is bad, control is performed by determining how much the transmission band can be narrowed based on the received electric field and the amount of data to be transmitted.

Therefore, in the transmission apparatus of this example, the D / U may be extremely deteriorated depending on the operation in a broadcasting station, for example, but such a situation can be avoided and efficient transmission can be performed. .
For example, when the D / U value on the receiving side is poor, a method of avoiding by changing the channel of the transmission apparatus has a small number of channels given to the broadcasting station and cannot use other channels. Occasionally, the operation will be hindered. On the other hand, in the transmission apparatus of this example, there is a possibility that the operation may be limited, but it is considered that the operation cannot be performed at all. In this example, since the optimum number of carriers and modulation mode are automatically set based on the received electric field and the volume of input data, the operation is simple.

In the transmission apparatus of this example, the transmission-side apparatus is configured by the transmission control unit (TC) 71 and the transmission high-frequency unit (TH) 72, and the reception high-frequency unit (RH) 73 and the reception control unit (RC) 74. Thus, the receiving side apparatus is configured.
In the receiving apparatus of this example, the receiving high-frequency unit 73 includes a receiving means with a function of receiving signals from the transmitting apparatus using the reception processing systems 1 to 7, and the detection circuit 8, 9, the comparator 41 of the CPU 11 using the comparator 10 and the function of detecting the reception quality (in this example, the input received electric field value (BL value) and the D / U value) constitute a quality detection means. The quality information transmission means is configured by the function of transmitting the reception quality information from the comparator 41 to the transmission side device via the telephone line 14, the reception control unit 74, and the LAN line 82.
Further, in the transmission side apparatus of this example, in the transmission control unit 71, the quality information receiving means is configured by the function of the CPU 53 receiving the reception quality information transmitted from the reception side apparatus via the LAN board 61. When the data is transmitted by the data conversion unit 51 or the digital modulation board 52, the CPU 53 controls the carrier number change switch 54 and the modulation mode change switch 55 to control the number of carriers and the modulation mode. Has been.

Here, the configuration of the system and apparatus according to the present invention is not necessarily limited to the configuration described above, and various configurations may be used. The present invention can also be provided as, for example, a method or method for executing the processing according to the present invention, a program for realizing such a method or method, or a recording medium for recording the program. It is also possible to provide various systems and devices.
The application field of the present invention is not necessarily limited to the above-described fields, and the present invention can be applied to various fields.
In addition, as various processes performed in the system and apparatus according to the present invention, for example, the processor executes a control program stored in a ROM (Read Only Memory) in hardware resources including a processor and a memory. A controlled configuration may be used, and for example, each functional unit for executing the processing may be configured as an independent hardware circuit.
The present invention can also be understood as a computer-readable recording medium such as a floppy (registered trademark) disk or a CD (Compact Disc) -ROM storing the control program, and the program (itself). The processing according to the present invention can be performed by inputting the program from the recording medium to the computer and causing the processor to execute the program.

It is a figure which shows the structural example of the receiving high frequency part (RH) of the transmission apparatus which concerns on one Example of this invention. It is a figure which shows the structural example of the transmission control part (TC) of the transmission apparatus which concerns on one Example of this invention. It is a figure which shows the structural example of the transmission apparatus which concerns on one Example of this invention. It is a figure which shows the structural example of the receiving high frequency part (RH) of a transmission apparatus.

Explanation of symbols

  1 .... Low noise amplifier (LNA) 2 .... Attenuator (PIN ATT) 3 .... Local oscillator 4. Mixer (MIX) 5 .... Low pass filter (LPF) 6 .... SAW unit 7, IF unit 8, 9, Detection circuit 10, Comparator 11, 53 CPU 12, Switch (SW) 13, Display 14, Telephone line (TEL line) , 21, 24..Amplifier, 22..SAW filter, 23..Attenuator (ATT) 31, 33..Diode, 32, 34..Capacitor, 41..Comparator, 42..ROM, 51. · Data conversion unit · 52 · · Digital modulation board · · · · Carrier number changeover switch · · · · Modulation mode changeover switch · · · · 61 · · LAN board · · · · Transmission control Part (TC), 72..Transmission high frequency part (TH), 73..Reception high frequency part (RH), 74..Reception control part (RC), 81..Micro line, 82..LAN line,

Claims (1)

In a transmission device that transmits a signal from a transmission-side device to a reception-side device,
The receiving apparatus receives a signal transmitted from the transmitting apparatus;
Quality detection means for detecting reception quality based on the signal received by the reception means;
Quality information transmission means for transmitting the reception quality information detected by the quality detection means to the transmission side device,
The transmission-side apparatus receives quality information receiving means transmitted from the reception-side apparatus;
A signal having a function of transmitting a signal to the receiving side device, and narrowing the transmission band when it is determined that the D / U is low based on the reception quality information received by the quality information receiving means; A data transmission means for transmitting
A transmission apparatus characterized by that.

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