JP2009302651A - Equalizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an equalizer capable of operating continuously even if a fault occurs at a cooling device. <P>SOLUTION: When the equalizer is activated, an IF signal is outputted from a distribution portion 10 via a switching portion 30. If a supervisory signal indicative that equalization processing is effective is transmitted from an equalization portion 50 after the activation, the IF signal is outputted from a digital/analogue conversion portion 80 via the switching portion 30. When malfunctions occur at both cooling devices 90-1 and 90-2 and an alarm signal is generated while the equalization processing is effective, the switching portion 30 is switched so that the IF signal from the distribution portion 10 may be outputted. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an equalization apparatus that suppresses multipath and multipath fading in a relay apparatus that relays a broadcast wave signal using, for example, an OFDM (Orthogonal Frequency Division Multiplexing) modulation scheme.

  In the terrestrial digital broadcasting system, for the purpose of expanding the broadcasting service area and resolving difficult viewing areas, a large number of relay devices are distributed in a predetermined area, and broadcast wave signals based on the OFDM modulation system are relayed in multiple stages at each relay device. The method is adopted. This relay device is provided with an equalization device that can equalize broadcast wave signals in order to suppress multipath, multipath fading, and the like (see, for example, Patent Documents 1 and 2).

  By the way, the said equalization apparatus is provided with the cooling device, the inside of an equalization apparatus is cooled with this cooling device, and the temperature rise in an apparatus by operation | movement of an equalization apparatus is suppressed. Then, the temperature in the apparatus is monitored, and when the monitored temperature exceeds the threshold value, the equalization process is stopped because a failure has occurred in the cooling apparatus.

However, in the conventional equalization apparatus as described above, the operation of the equalization apparatus is stopped when the cooling apparatus breaks down, which hinders the relay of the broadcast wave signal.
Japanese Patent Laid-Open No. 2001-333342 Japanese Patent Laid-Open No. 11-69246

  As described above, in the conventional equalization apparatus, if an abnormality occurs in the cooling apparatus, the operation of the equalization apparatus is stopped, which hinders the relay of the broadcast wave signal.

  The present invention has been made under the circumstances described above, and an object of the present invention is to provide an equalization apparatus that can be continuously operated even when an abnormality occurs in the cooling apparatus.

  In order to achieve the above object, an equalizing apparatus according to the present invention distributes a broadcast wave signal in an intermediate frequency band to two systems, and outputs a first and a second broadcast wave signal; An orthogonal demodulator that orthogonally demodulates a broadcast wave signal, and an equalizer that performs equalization processing on the orthogonal demodulated signal.If the equalization processing is valid, an effective signal is output. An equalization unit that outputs an invalid signal, an orthogonal modulation unit that orthogonally modulates the equalized signal to obtain a third broadcast wave signal, the second broadcast wave signal, and the third broadcast wave signal A switching unit that selectively derives one of them, and at least the equalization unit is cooled, and a cooling unit that outputs a first alarm signal when an abnormality occurs in the cooling function And receiving the valid signal, the switching unit receives the third broadcast wave signal. A first control that causes the switching unit to select the second broadcast wave signal upon receipt of the invalid signal, and the switching unit selects the third broadcast wave signal. A control unit that performs a second control that causes the switching unit to select the second broadcast wave signal when the first alarm signal is received.

  In the equalization apparatus having the above configuration, even if the equalization processing is effective, when the cooling unit fails, the switching unit is switched to output the broadcast wave signal from the distribution unit, and the input signal is directly I am trying to output. As a result, even when the cooling means is out of order, the equalization apparatus is continuously operated.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where abnormality arises in a cooling device, the equalization apparatus which can be operated continuously can be provided.

  Hereinafter, embodiments of an equalization apparatus according to the present invention will be described in detail with reference to the drawings. In the following description, it is an equalizer used in a relay device that relays an OFDM modulation broadcast wave signal transmitted from a base station, and the received broadcast wave signal is transmitted to the equalizer. It is assumed that it is converted into a signal and given.

  FIG. 1 is a block diagram showing a functional configuration of the equalization apparatus. In FIG. 1, the IF signal is distributed into two systems by a distribution unit 10, one of which is supplied to an analog-digital (A / D) conversion unit 20 and the other is supplied to a switching unit 30.

  The IF signal is converted into a digital signal by the analog-digital conversion unit 20, is orthogonally demodulated by the orthogonal demodulation unit 40, becomes a baseband OFDM modulated wave, and is supplied to the equalization unit 50.

  The equalization unit 50 performs multipath equalization processing and symbol determination processing on the input OFDM modulated wave. At this time, the equalization unit 50 demodulates the OFDM modulation wave and performs equalization processing by obtaining the frame synchronization of the information signal on the time axis obtained after the demodulation. Here, when the frame synchronization of the information signal is taken and the equalization processing of the input OFDM modulated wave can be performed effectively, the equalization unit 50 monitors that the equalization function is effective. The control unit 60 is notified of the signal. If the frame synchronization cannot be achieved and the equalization process cannot be effectively performed, a monitoring signal indicating that the equalization function is invalid is notified to the control unit 60.

  The OFDM modulated wave equalized by the equalization unit 50 is orthogonally modulated by the orthogonal modulation unit 70, converted into an IF signal by the digital-analog (D / A) conversion unit 80, and supplied to the switching unit 30. In the present embodiment, the quadrature demodulation unit 40, the quadrature modulation unit 70, and the equalization unit 50 are realized by an FPGA (Field Programmable Gate Array) and mounted on the equalization apparatus.

  The switching unit 30 receives the IF signal distributed by the distribution unit 10 and the IF signal from the digital-analog conversion unit 80, and selectively derives one of them.

  The cooling devices 90-1 and 90-2 are devices that perform cooling processing of FGPA, and are duplexed. The cooling devices 90-1 and 90-2 output an alarm signal to the control unit 60 when an abnormality occurs in the cooling function.

  The abnormality detection unit 100 detects an abnormality in the analog-digital conversion unit 20, the quadrature demodulation unit 40, the quadrature modulation unit 70, the digital-analog conversion unit 80, etc. of the equalizer, and outputs an alarm signal to the control unit 60. For example, in the digital-analog conversion unit 80, the abnormality here means that an abnormality occurs in the clock signal at the time of signal conversion.

  The receiving unit 110 receives an equalization function on / off signal from an external device (not shown), and supplies the received equalization function on / off signal to the control unit 60.

  When the control unit 60 receives a monitoring signal indicating that the equalization processing is valid from the equalization unit 50, the control unit 60 performs switching control so that the switching unit 30 selects the IF signal from the digital-analog conversion unit 80, and the equalization processing is performed. When a monitoring signal indicating invalidity is received, switching control is performed so that the switching unit 30 selects the IF signal from the distribution unit 10. Further, when the control unit 60 receives the alarm signal from both the cooling devices 90-1 and 90-2 while the switching unit 30 derives the IF signal from the digital-analog conversion unit 80, the control unit 60 The switching control is performed so that 30 selects the IF signal from the distribution unit 10. When an alarm signal is received from only one of the cooling devices 90-1 and 90-2, the switching control of the switching unit 30 is not performed and the equalization process is continued. Further, when the control unit 60 receives an alarm signal from the abnormality detection unit 100, the control unit 60 performs switching control so that the switching unit 30 selects the IF signal from the distribution unit 10. Furthermore, when receiving the equalization function off signal from the external device, the control unit 60 performs switching control so that the switching unit 30 selects the IF signal from the distribution unit 10.

  In addition, when the control unit 60 receives alarm signals from both the cooling devices 90-1 and 90-2 and performs switching control of the switching unit 30, the quadrature demodulation unit 40 and the quadrature modulation unit that serve as heat sources. 70 and control to reset the FPGA on which the equalization unit 50 is mounted.

  FIG. 2 is a diagram illustrating mode switching by the control unit 60 according to an embodiment of the present invention. Here, the mode in which the switching unit 30 derives the IF signal from the distribution unit 10 is referred to as a bypass mode, and the mode in which the switching unit 30 derives the IF signal from the digital-analog conversion unit 80 is referred to as an equalization mode.

  At the time of starting the equalization apparatus, the equalization function in the equalization unit 50 is invalid, and the switching unit 30 is controlled to enter the bypass mode (state 1 in FIG. 2). The control unit 60 may receive an alarm signal from the cooling devices 90-1 and 90-2, an alarm signal from the abnormality detection unit 100, and an equalization function on / off signal from an external device in the bypass mode at startup. The mode is not switched.

  After the apparatus is activated, the control unit 60 receives a monitoring signal indicating that the equalization function is effective from the equalization unit 50, and when there is no alarm signal from the cooling devices 90-1 and 90-2 and the abnormality detection unit 100, The switching unit 30 is controlled to switch the mode to the equalization mode (state 2 in FIG. 2). When an equalization function off signal is received in this state, the mode is switched to the bypass mode (state 3 in FIG. 2).

  When the control unit 60 receives an alarm signal from both the cooling devices 90-1 and 90-2 in the equalization mode after the device is started, the control unit 60 switches the mode to the bypass mode (state 4 in FIG. 2). Further, when the control unit 60 receives an alarm signal from the abnormality detection unit 100 in the equalization mode, the control unit 60 switches the mode to the bypass mode (state 5 in FIG. 2). Further, when receiving a monitoring signal indicating that the equalization function is invalid from the equalization unit 50 in the equalization mode, the control unit 60 switches the mode to the bypass mode (state 6 in FIG. 2).

  As described above, the equalization apparatus according to the above embodiment is in the bypass mode when the equalization apparatus is activated, and after the activation, the equalization unit 50 issues a monitoring signal indicating that the equalization processing is effective. Then, the switching unit 30 is switched to switch to the equalization mode. In the equalization mode, when both the cooling devices 90-1 and 90-2 fail and generate an alarm signal, the mode is switched to the bypass mode. As a result, even when both the cooling devices 90-1 and 90-2 fail, the equalization device can directly fold and output the input IF signal without stopping the operation itself. Become. In the bypass mode, since the cooling devices 90-1 and 90-2 are not used, the failed cooling devices 90-1 and 90-2 can be maintained during that time.

  Further, when the equalization apparatus receives an alarm signal from the abnormality detection unit 100 in the equalization mode, the mode is switched to the bypass mode. Thereby, even if an abnormality occurs in each component of the equalizer, the equalizer can output the IF signal in the bypass mode. In the bypass mode, since components other than the distribution unit 10 and the switching unit 30 are not used, it is possible to maintain a failed component during that time.

  Therefore, since the equalization apparatus according to the present invention can be continuously operated even when an abnormality occurs in the cooling apparatus, the relay apparatus including the equalization apparatus continuously transmits the broadcast wave signal. Can be relayed.

  The present invention is not limited to the above embodiment. For example, although the equalization apparatus provided in the relay apparatus has been described, the present invention is not limited to the relay apparatus, and can be similarly implemented even when provided in the reception apparatus, for example.

  Moreover, although the case where a clock synchronization cannot be taken is mentioned as an example where an equalization process becomes invalid, the factor which an equalization process becomes invalid is not necessarily limited to this.

  Furthermore, the present invention can be embodied by modifying the constituent elements without departing from the spirit of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment.

It is a block diagram which shows the function structure of the equalization apparatus which concerns on one Embodiment of this invention. It is a figure which shows the switching of the mode by the control part of FIG.

Explanation of symbols

10 ... Distributing unit 20 ... A / D
30 ... Switching unit 40 ... Quadrature demodulation unit 50 ... Equalization unit 60 ... Control unit 70 ... Quadrature modulation unit 80 ... D / A
90-1, 90-2 ... Cooling device 100 ... Abnormality detection unit 110 ... Reception unit

Claims (4)

A distribution unit that distributes the broadcast wave signal of the intermediate frequency band to two systems and outputs the first and second broadcast wave signals;
An orthogonal demodulator for orthogonally demodulating the first broadcast wave signal;
Equalizing the orthogonal demodulated signal, if the equalization processing is valid, outputs an effective signal, and if invalid, an equalization unit that outputs an invalid signal;
An orthogonal modulation unit that orthogonally modulates the equalized signal to form a third broadcast wave signal;
A switching unit that receives the second broadcast wave signal and the third broadcast wave signal and selectively derives one of them;
A cooling means for cooling at least the equalization section, and when an abnormality occurs in the cooling function, a cooling means for outputting a first alarm signal;
Receiving the valid signal, causing the switching unit to select the third broadcast wave signal; receiving the invalid signal, causing the switching unit to select the second broadcast wave signal; and the switching unit When the first broadcast wave signal is selected, the control unit performs a second control that causes the switching unit to select the second broadcast wave signal when the first warning signal is received. An equalizing apparatus comprising: An abnormality detection unit that detects an abnormality in at least one of the quadrature demodulation unit, the equalization unit, and the quadrature modulation unit, and transmits a second alarm signal;
The equalization apparatus according to claim 1, wherein the control unit causes the switching unit to select the second broadcast wave signal when receiving the second alarm signal. When the equalization function off signal is given externally,
The equalization apparatus according to claim 1, wherein the control unit causes the switching unit to select the second broadcast wave signal according to the equalization function off signal. The quadrature demodulation unit, the quadrature modulation unit, and the equalization unit are formed by an FPGA (Field Programmable Gate Array),
The equalization apparatus according to claim 1, wherein the cooling unit cools the FPGA.

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