JP6080173B2 - Signal processing apparatus, receiving apparatus, CATV head end, and CATV system - Google Patents

Description

  The present invention relates to a signal processing device, a receiving device, a CATV head end, and a CATV system.

  For example, a CATV head end provided in a CATV station is required to prevent the transmission signal from being stopped to the maximum extent. Therefore, the receiving apparatus used in the CATV head end employs a redundant configuration of the receiving system. For example, in the case of a receiving device that receives an aerial transmission wave and retransmits a signal, an operation is performed that includes a working antenna and a spare antenna, and monitors the signal level of the signal received by these antennas to switch the antenna. (See Patent Document 1).

JP 2011-155328 A

  However, when switching the receiving system by monitoring the overall signal level at the input stage of the receiving device, such as the received signal from the antenna, abnormalities in the received signal cannot be detected properly, and the transmission from the receiving device is stopped. Or, unnecessary switching of the reception system may occur. This is because the received signal input to the receiving apparatus is a mixture of signals of a plurality of channels and includes a plurality of signals having different frequencies.

  For example, when switching the reception system by monitoring the signal level at the input stage of the receiving device, even if the signal level in some frequency regions falls below the allowable range due to fading, etc. If the signal level of the entire signal does not drop below the threshold value, the receiving system cannot be switched, and the channel whose signal level has fallen stops. On the other hand, if the signal level in some frequency regions decreases due to normal reasons such as maintenance on the transmitting side, the signal level of the entire received signal is also affected and decreases below the threshold value. Switching will occur.

  The present invention has been made in view of the above, and an object of the present invention is to provide a signal processing device, a receiving device, a CATV head end, and a CATV system capable of appropriately switching a receiving system.

  In order to solve the above-described problems and achieve the object, a signal processing apparatus according to the present invention includes a first down-converter that converts an input high-frequency signal into an intermediate frequency signal, and a signal of a desired channel from the intermediate frequency signal. A working system unit having a first IF unit for extracting the first IF unit and a first detection unit for outputting a first detection voltage provided in a subsequent stage of the first IF unit, and the input high-frequency signal as an intermediate frequency signal A second down converter for converting to a second IF section, a second IF section for extracting the signal of the desired channel from the intermediate frequency signal, and a second IF section that is provided after the second IF section and outputs a second detected voltage. And whether to output a signal from the active system or a signal from the standby system based on the first detection voltage and the second detection voltage. Determination unit , Characterized in that it comprises a switching unit for switching the route on the working line or the preliminary system in accordance with the determination.

  In the signal processing device according to the present invention, in the above invention, the first detection voltage is fed back to at least one of the first down converter and the first IF unit, Based on the voltage, automatic gain control of the amplifier provided in the working system unit is performed, and the second detection voltage is fed back to at least one of the second down converter and the second IF unit. The automatic gain control of the amplifier provided in the standby system unit is performed based on the second detection voltage.

  In the signal processing device according to the present invention, in the above invention, the determination unit includes a first comparison unit that compares a signal level in a subsequent stage of the first IF unit and a threshold for the working system, and the second Switching for the switching unit based on a comparison result between the second comparison unit that compares the signal level in the subsequent stage of the IF unit and the threshold for the standby system, and the first comparison unit and the second comparison unit And a switching control unit that performs control.

  In the signal processing apparatus according to the present invention, in the above invention, an up-converter unit that converts an intermediate frequency signal output from the active system unit or the standby system unit into a high-frequency signal and outputs the high-frequency signal to the outside is provided in the switching unit. It is provided in the latter stage.

  The signal processing apparatus according to the present invention includes a first down converter that converts an input high-frequency signal into an intermediate frequency signal, a first IF unit that extracts a signal of a desired channel from the intermediate frequency signal, and the first Active section having a first detector for outputting a first detection voltage provided after the IF section, a second down converter for converting an inputted high frequency signal into an intermediate frequency signal, and the intermediate frequency A standby system unit including a second IF unit that extracts a signal of the desired channel from a signal and a second detection unit that is provided at a subsequent stage of the second IF unit and outputs a second detection voltage; An up-converter unit that converts the intermediate frequency signal output from either the active system unit or the standby system unit into a high-frequency signal and outputs the high-frequency signal; and the high-frequency signal output from the up-converter unit And a branch section for branching a part, and a part of the high-frequency signal branched by the branch portion is input to the other of said working line section or the preliminary system unit.

  The signal processing apparatus according to the present invention includes a first down converter that converts an input high-frequency signal into an intermediate frequency signal, a first IF unit that extracts a signal of a desired channel from the intermediate frequency signal, and the first Active section having a first detector for outputting a first detection voltage provided after the IF section, a second down converter for converting an inputted high frequency signal into an intermediate frequency signal, and the intermediate frequency A standby system unit including a second IF unit that extracts a signal of the desired channel from a signal and a second detection unit that is provided at a subsequent stage of the second IF unit and outputs a second detection voltage; An up-converter unit that converts the intermediate frequency signal output from either the active system unit or the standby system unit into a high-frequency signal and outputs the high-frequency signal; and the high-frequency signal output from the up-converter unit A branching unit that branches the signal, a distribution unit that distributes the high-frequency signal branched by the branching unit to the first high-frequency signal and the second high-frequency signal, and the first high-frequency signal and the high-frequency signal input from the outside A first input switching unit that selects one of the signals and outputs the selected signal to the active system unit, and selects one of the second high-frequency signal and a high-frequency signal input from the outside to select the spare A second input switching unit that outputs to the system unit, an intermediate frequency signal that is input from the active system unit, and an intermediate frequency signal that is input from the backup system unit are selected and output to the up-converter And at least one of the first input switching unit and the second input switching unit inputs a high-frequency signal input from the outside to the active system unit or the standby system unit. Feature To.

  The signal processing apparatus according to the present invention is the signal processing apparatus according to the first aspect, wherein the first input switching unit, the second input switching unit, and the second detection unit are based on the first detection voltage and the second detection voltage. It further comprises a determination unit that controls the switching unit.

  In addition, a receiving device according to the present invention includes a plurality of the above signal processing devices, a first distribution unit that distributes a signal of the working system to an input terminal of each of the working system units of each of the signal processing devices, and the signal processing device A second distribution unit that distributes the signal of the standby system to the input terminal of each of the standby system unit, and a mixing unit that mixes the signal output from each output terminal of the signal processing device. And

  In the reception device according to the present invention, the signal input to the first distribution unit and the signal input to the second distribution unit are signals transmitted from different transmitting stations in the above invention. It is characterized by being configured.

  In the receiving apparatus according to the present invention, the signal input to the first distribution unit and the signal input to the second distribution unit are signals transmitted from the same transmitting station. It is comprised so that it may be.

  In the receiving apparatus according to the present invention, the signal input to the first distribution unit and the signal input to the second distribution unit are transmitted from different transmitting stations in the above invention. It is characterized by including a signal.

  According to another aspect of the present invention, there is provided a CATV headend including the above-described receiving device and a transmission device that transmits a signal output from the receiving device.

  The CATV system according to the present invention includes a CATV head end, a signal transmission path for transmitting a signal transmitted from the CATV head end, and a subscriber home apparatus for receiving a signal transmitted through the signal transmission path. It is characterized by providing.

  The signal processing device, the receiving device, the CATV head end, and the CATV system according to the present invention have an effect that the receiving system can be appropriately switched.

FIG. 1 is a diagram showing a schematic configuration of a CATV system according to the first embodiment of the present invention. FIG. 2 is a diagram illustrating a schematic configuration of the signal processing device and the reception device according to the first embodiment of the present invention. FIG. 3 is a block diagram illustrating the function of the determination unit. FIG. 4 is a determination table for switching control. FIG. 5 is a schematic circuit diagram illustrating a hardware configuration example of the determination unit. FIG. 6 is a diagram illustrating an application example in which the active system and the standby system each include a plurality of antennas. FIG. 7 is a diagram illustrating an application example in the case where a BS / CS antenna is provided in the active system and the standby system. FIG. 8 is a diagram showing a schematic configuration of a signal processing device and a receiving device according to the second embodiment of the present invention. FIG. 9 is a block diagram illustrating the function of the determination unit. FIG. 10 is a diagram showing a schematic configuration of a signal processing device and a receiving device according to the third embodiment of the present invention. FIG. 11 is a block diagram illustrating the function of the determination unit. FIG. 12 is a diagram illustrating a signal path pattern by switching the switch, the first input switch, and the second input switch. FIG. 13 is a diagram schematically showing a signal path in the pattern 1. FIG. 14 is a diagram schematically showing a signal path in the pattern 2. FIG. 15 is a diagram schematically showing a signal path in the pattern 3. FIG. 16 is a diagram schematically illustrating a signal path in the pattern 4. FIG. 17 is a flowchart showing a signal path switching algorithm. FIG. 18 is a diagram illustrating a schematic configuration of a signal processing device and a reception device as a comparative example.

  Hereinafter, a signal processing device, a receiving device, a CATV head end, and a CATV system according to embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments described below. Moreover, in each drawing, the same code | symbol is attached | subjected suitably to the same or corresponding element. Furthermore, it should be noted that the drawings are schematic, and dimensional relationships between elements may differ from actual ones. Even between the drawings, there are cases in which portions having different dimensional relationships and ratios are included.

(Comparative example)
In order to clarify the effects of the signal processing device, the receiving device, the CATV head end, and the CATV system according to the embodiment of the present invention, the signal processing device, the receiving device, the CATV head end, and the CATV system to which the present invention is not applied will be described. To do. FIG. 18 is a diagram illustrating a schematic configuration of a signal processing device and a reception device as a comparative example.

  A receiving apparatus 500 shown in FIG. 18 is an apparatus provided in the head end of the CATV system in the CATV station in the CATV system. As illustrated in FIG. 18, the receiving device 500 includes an input system switching unit 510, a distributor 520, signal processing devices 530-1 to 530-n, and a mixer 540. Here, n is an integer of 2 or more.

  As shown in FIG. 18, the receiving apparatus 500 employs a redundant configuration in which the working antenna 10 and the spare antenna 20 are provided in the receiving system. A high-frequency signal (hereinafter referred to as an RF signal) input from the active antenna 10 and the standby antenna 20 is amplified by the amplifier 11 and the amplifier 21 provided in the respective transmission paths and is input to the input system switching unit 510. Have been entered. The input system switching unit 510 is a device for switching the signal path between the active system and the standby system based on the signal level of the RF signal input from the active antenna 10 and the standby antenna 20.

  As illustrated in FIG. 18, the input system switching unit 510 includes branching units 511 and 512, detectors 513 and 514, a determination unit 515, and a switching unit 516. The branching device 511 branches the RF signal input from the working antenna 10, and the detector 513 detects the signal level of the RF signal branched by the branching device 511. Similarly, the branching device 512 branches the RF signal input from the standby antenna 20, and the detector 514 detects the signal level of the RF signal branched by the branching device 512. The determination unit 515 performs switching control in the switch 516 based on the signal levels of the active system and the standby system detected by the detectors 513 and 514. The distributor 520 distributes the RF signal of the working system or the RF signal of the standby system switched from the working system by the switch 516 to the signal processing devices 530-1, ..., 530-n.

  The signal processing devices 530-1,..., 530-n are so-called signal processors, and have a function of retransmitting after extracting a signal of a desired channel from an input signal. In the configuration example illustrated in FIG. 18, the signal processing device 530-1 includes a down converter 531, an IF unit 532, a branching unit 533, an upconverter 534, and a detector 535. Since the signal processing devices 530-2,..., 530-n have the same configuration as the signal processing device 530-1, the description thereof is omitted here.

  The down converter 531 converts the RF signal input to the signal processing device 530-1 into an intermediate frequency and outputs an intermediate frequency signal (hereinafter referred to as an IF signal) to the IF unit 532. The IF unit 532 includes an out-of-band removal filter therein, and extracts a signal of a desired channel from the input IF signal. The IF signal extracted from only the signal of the desired channel by the IF unit 532 is branched by the branching device 533, one of which is input to the up-converter 534 and the other is input to the detector 535. The up-converter 534 converts the input IF signal into an RF signal and outputs it to the mixer 540. On the other hand, the detector 535 detects the signal level of the IF signal and performs feedback for so-called automatic gain control (AGC) that adjusts the gains of the amplifiers provided in the down converter 531 and the IF unit 532.

  Finally, the RF signals output from the signal processing devices 530-1,..., 530-n are mixed by the mixer 540 and transmitted to the subsequent transmission device.

  In the comparative example of the signal processing device, the receiving device, and the CATV head end and CATV system using the signal processing device configured as described above, the signal level of the entire signal input from the active antenna 10 or the standby antenna 20 is monitored. Based on this, the receiving system is switched.

  However, in the configuration of this comparative example, it is impossible to detect reception abnormality of only some channels from reception signals including signals of a plurality of channels. Therefore, with the configuration of this comparative example, it is not possible to realize appropriate switching of the reception system for each channel.

  Therefore, as described below, the signal processing device, the receiving device, the CATV head end, and the CATV system according to the embodiment of the present invention detect reception abnormality of only some channels from the received signals including signals of a plurality of channels. The receiving system can be switched.

(First embodiment)
FIG. 1 is a diagram showing a schematic configuration of a CATV system according to the first embodiment of the present invention. A CATV system 1 shown in FIG. 1 includes a CATV head end 3 provided in a CATV station 2, a signal transmission path 4, and a subscriber home device 6 provided in the subscriber home 5. The CATV head end 3 includes a working antenna 10, a spare antenna 20, a receiving device 100, and a transmission device 200.

  In the CATV system 1 of the first embodiment of the present invention, the working system RF signal transmitted from the transmitting station 7 is received by the working antenna 10, and the standby system RF signal transmitted from the transmitting station 8 is received by the standby antenna 20. Receive at. Further, each signal transmitted from the working antenna 10 and the standby antenna 20 is received by the receiving apparatus 100, and either one of the working system or the standby system is output from the receiving apparatus 100, and the signal transmission path 4 is transmitted. To the subscriber home device 6 provided in the subscriber home 5.

  FIG. 2 is a diagram illustrating a schematic configuration of the signal processing device and the reception device according to the first embodiment of the present invention. As shown in FIG. 2, the receiving apparatus 100 includes a first distributor 121, a second distributor 122, signal processing apparatuses 130-1 to 130-n, and a mixer 140. . Note that n is an integer of 2 or more. As can be seen by comparing FIG. 18 and FIG. 2, the receiving device 100 according to the first embodiment of the present invention does not have a configuration corresponding to the input system switching unit 510 in the comparative example.

  The first distributor 121 and the second distributor 122 are devices for distributing the RF signals of the working system and the standby system to the signal processing devices 130-1,..., 130-n, respectively. In the configuration example shown in FIG. 2, the RF signal from the active antenna 10 is input to the first distributor 121, and the RF signal from the standby antenna 20 is input to the second distributor 122. However, as will be shown in a later application example, the signals input to the first distributor 121 and the second distributor 122 are not limited to the received signals from the antennas. The CATV system of the present embodiment is not limited to the method of acquiring the received signal, but includes the receiving device 100 in the CATV head end 3 and retransmits the received signal to the subscriber home device 6 such as the image receiving device of each subscriber. Any CATV system can be used. In this configuration example, the RF signals input from the active antenna 10 and the standby antenna 20 are amplified by the amplifier 11 and the amplifier 21 provided in the transmission path in the middle of each, and each of the first distributors 121 is amplified. And is input to the second distributor 122.

  The signal processing devices 130-1,..., 130-n are so-called signal processors, and are two systems of signals input to the input terminal of the working system section 130-1A and the input terminal of the standby system section 130-1B. After extracting a signal of a desired channel from each, a function of selecting a signal of one desired channel and retransmitting it from an output terminal is provided. Therefore, the two input terminals of the working system section 130-1A and the standby system section 130-1B are connected to the first distributor 121 and the second distributor 122, respectively, and the output terminal of the signal processing apparatus 130-1 Is connected to the mixer 140.

  The signal processing devices 130-1,..., 130-n described here can be used as, for example, an FM signal processor, an OFDM signal processor, a BS-IF signal processor, or a CS-IF signal processor. Since the configuration of the signal processing device 130-1 is a representative example, description of the configuration of the signal processing devices 130-2,..., 130-n is omitted below.

  As shown in FIG. 2, the signal processing device 130-1 includes a first down converter 131a, a second down converter 131b, a first IF unit 132a, a second IF unit 132b, and a first branching unit 133a. And a second branching device 133b, a first detector 135a, a second detector 135b, a determination unit 136, a switch 137, and an upconverter 134. The signal processing device 130-1 includes an active system section 130-1A and a standby system section 130-1B, and includes a first down converter 131a, a first IF section 132a, a first branching device 133a, and a first The detector 135a belongs to the working system section 130-1A, and the second down converter 131b, the second IF section 132b, the second branching device 133b, and the second detector 135b are connected to the standby system section 130-1B. belong to. The signal output from the working system section 130-1A and the signal output from the standby system section 130-1B are switched by the switch 137, and after passing through the up-converter 134, are output terminals of the signal processing apparatus 130-1. To.

  The first down converter 131a converts the RF signal input to the working system section 130-1A into an intermediate frequency, and outputs the converted IF signal to the first IF section 132a. The first IF unit 132a includes an out-of-band removal filter and the like inside, and extracts a signal of a desired channel from the input IF signal. The out-of-band removal filter is configured by, for example, a surface acoustic wave filter or a band-pass filter, and extracts only a signal having a predetermined frequency included in a narrow band. Note that a typical method of using a filter is configured to extract only a single frequency. However, in a case where a plurality of frequencies are bundled to form one channel, the out-of-band removal filter can be used for a plurality of frequencies. This does not exclude the configuration for extracting the signal.

  The IF signal obtained by extracting only the signal of the desired channel by the first IF unit 132a is branched by the first branching unit 133a, one is input to the switch 137, and the other is input to the first detector 135a. The The first detector 135a detects the signal level of the IF signal and outputs a first detection voltage. The first detection voltage is fed back to the AGC loop that automatically controls the gain of the amplifier provided in the first down converter 131a or the first IF unit 132a, and is input to the determination unit 136.

  Thus, in the working system section 130-1A, it is preferable to perform automatic gain control using the first detection voltage used in the determination section 136, since the circuit configuration can be simplified.

  Similarly, the second down converter 131b converts the RF signal input to the standby system unit 130-1B into an intermediate frequency, and outputs the converted IF signal to the second IF unit 132b. The second IF unit 132b includes an out-of-band removal filter and the like similar to the above, and extracts a signal of a desired channel from the input IF signal. Here, the desired channel of the first IF unit 132a and the desired channel of the second IF unit 132b are the same channel. The IF signal obtained by extracting only the signal of the desired channel by the second IF unit 132b is branched by the second branching device 133b, one is input to the switch 137, and the other is input to the second detector 135b. The The second detector 135b detects the signal level of the IF signal and outputs a second detection voltage. The second detection voltage is fed back to the AGC loop that automatically controls the gain of the amplifier provided in the second down converter 131b or the second IF unit 132b, and is input to the determination unit 136.

  As described above, the standby system unit 130-1B is also preferable because the circuit configuration can be simplified by performing the automatic gain control using the second detection voltage used in the determination unit 136.

  With the configuration described above, the determination unit 136 includes the signal level of the IF signal in the working system unit 130-1A detected by the first detector 135a and the standby system unit 130 detected by the second detector 135b. The signal level of the IF signal at -1B is input. Here, the signal level detected by the first detector 135a is the signal level of the IF signal obtained by extracting only the signal of the desired channel by the first IF unit 132a, and is detected by the second detector 135b. The signal level is the signal level of the IF signal obtained by extracting only the signal of the desired channel by the second IF unit 132b. The first detector 135a and the second detector 135b are incorporated in an AGC loop that automatically controls the gain of the amplifiers provided in the working system section 130-1A and the standby system section 130-1B, respectively. Therefore, the signal level detected by the first detector 135a and the second detector 135b is the signal level after the automatic gain control is performed. The determination unit 136 performs switching control of the switch 137 based on the signal levels detected by the first detector 135a and the second detector 135b. A specific example of the determination method in the determination unit 136 will be described in detail later.

  Based on the control signal from the determination unit 136, the switch 137 outputs the IF signal from the first branching device 133a to the upconverter 134 or outputs the IF signal from the second branching device 133b to the upconverter 134. Switch whether to do.

  The up-converter 134 converts the IF signal output from the switch 137 into an RF signal. Note that the RF signal converted by the up-converter 134 may have the same frequency as the RF signal input to the signal processing device 130-1 or a different frequency. The RF signals output from the signal processing devices 130-1,..., 130-n are mixed by the mixer 140 and transmitted to the subsequent transmission device 200.

  Here, the function and configuration of the determination unit 136 will be described in more detail.

  FIG. 3 is a block diagram illustrating the function of the determination unit 136. As shown in FIG. 3, the determination unit 136 includes a first comparison unit 136a, a second comparison unit 136b, a threshold setting unit 136c, and a switch control unit 136d.

  The first comparison unit 136a compares the signal level detected by the first detector 135a with the threshold value for the working system, and determines whether the signal level of the working system is High or Low with respect to the threshold value. It is configured to make a determination. Similarly, the second comparison unit 136b compares the signal level detected by the second detector 135b with the threshold value for the standby system, and the signal level of the standby system is High or Low with respect to the threshold value. It is configured to determine whether there is any. The threshold value setting unit 136c is a means for setting a threshold value for the working system and a threshold value for the standby system. The threshold value for the active system and the threshold value for the standby system may be set to the same value, but may be set to different values independently. The threshold value for the working system and the threshold value for the standby system set by the threshold setting unit 136c correspond to the signal level of the IF signal after only the signal of the desired channel is extracted by the first IF unit 132a and the second IF unit 132b. Since it is a threshold, it is a threshold for each channel.

  The switch control unit 136d is configured to perform switching control of the switch 137 based on the output of the first comparison unit 136a and the output of the second comparison unit 136b. As described above, the switch 137 is configured to receive the IF signal of the working system and the IF signal of the protection system and output either the IF signal of the working system or the IF signal of the protection system. . The switching control performed by the switch controller 136d is performed based on, for example, a determination table as shown in FIG.

  As shown in FIG. 4, when the signal level of the working system is High and the signal level of the standby system is High, the switch controller 136d causes the switch 137 to output the IF signal of the working system. The switch 137 is controlled. Similarly, when the signal level of the working system is High and the signal level of the standby system is Low, the switch controller 136d sets the switch 137 so that the switch 137 outputs the IF signal of the working system. Control. On the other hand, when the signal level of the active system is Low and the signal level of the standby system is High, the switch controller 136d controls the switch 137 so that the switch 137 outputs the IF signal of the standby system. To do. Further, when the signal level of the working system is Low and the signal level of the standby system is Low, the switch controller 136d controls the switch 137 so that the switch 137 outputs the IF signal of the working system. To do.

  Note that the switching control algorithm described above is merely an example, and can be appropriately changed according to the operation policy of the signal processing apparatus, the receiving apparatus, and the receiving station using the CATV system of the present embodiment. For example, when the signal level of the working system is Low and the signal level of the standby system is Low, the switch controller 136d controls the switch 137 so that the switch 137 outputs the IF signal of the standby system. It is good also as operation to do. In addition, when the signal level of the active system is Low and the signal level of the standby system is Low, it is determined that the broadcast has ended on that channel, and the control is automatically switched to the control at the end of the broadcast. May be. Furthermore, when the signal level of the working system is Low and the signal level of the standby system is Low, it may be possible to separately perform control or the like so as to issue a warning signal to the operator.

  FIG. 5 is a schematic circuit diagram illustrating a hardware configuration example of the determination unit 136. The schematic circuit diagram shown in FIG. 5 shows an example of a circuit configuration for realizing the function of the determination unit 136 described above.

  As illustrated in FIG. 5, the determination unit 136 includes a first comparator 1361, a second comparator 1362, a first variable power supply 1363, a second variable power supply 1364, an arithmetic unit (CPU) 1365, and a memory 1366. And.

As shown in FIG. 5, the first detection voltage V ₁ detected by the first detector 135 a is input to the − terminal of the first comparator 1361, and the + terminal of the first comparator 1361 is input. Is _supplied with the first reference voltage V _ref1 set by the first variable power source 1363. The first reference voltage V _ref1 is a voltage used as a threshold for the current system, and is set by the CPU 1365 and an external setting input unit. The first comparator 1361, the first detection voltages _{V 1} and compares the first reference voltage _{V ref1,} the direction of the first detection voltages _{V 1} first reference voltage a voltage higher than _{V ref1} in some cases, it outputs a High signal (i.e. a predetermined positive voltage), when towards the first detection voltage _{V 1} is a voltage lower than the reference voltage _{V ref1,} and outputs a low signal (i.e. zero voltage).

Similarly, the second comparator 1362 - The terminal, the second detection voltage _{V 2} in which the second detector 135b detects are inputted to the + terminal of the second comparator 1362, the second The second reference voltage V _ref2 set by the variable power supply 1364 is input. The second reference voltage V _ref2 is a voltage used as a threshold for the standby system, and is set by the CPU 1365 and an external setting input unit. Second comparator 1362, the second and the detection voltage _{V 2} is compared with the second reference voltage _{V ref2,} towards the second detection voltage _{V 2} is the second reference voltage _{V ref2} voltage higher than in some cases, and outputs a High signal when the second towards the second detection voltage _{V 2} is a voltage lower than the reference voltage _{V ref2,} it outputs a low signal.

  The CPU 1365 outputs a control signal to the switch 137 based on the output of the first comparator 1361 and the output of the second comparator 1362. The control signal output by the CPU 1365 is output based on, for example, the determination table shown in FIG. The memory 1366 is a storage device that stores a determination table referred to by the CPU 1365.

  In FIG. 5, the CPU 1365 and the memory 1366 are described as being configured in the determination unit 136. However, the circuit configuration is not limited to the configuration illustrated in FIG. 5. For example, the CPU 1365 and the memory 1366 may be provided outside the signal processing device 130-1, and may be configured to be shared with other signal processing devices 130-2, ..., 130-n.

  With the circuit configuration as described above, the first comparison unit 136a illustrated in FIG. 3 is realized by the first comparator 1361 and the first variable power source 1363, and the second comparison unit 136b includes the second comparison unit 136b. This is realized by the comparator 1362 and the second variable power source 1364. Further, the threshold setting unit 136c and the switch controller 136d illustrated in FIG. 3 are realized by the CPU 1365 and the memory 1366.

  Here, the effects of the signal processing devices 130-1,..., 130-n and the receiving device 100 of the present embodiment described above will be summarized.

  The signal processing devices 130-1,..., 130-n of the present embodiment include the first detection voltage and the second detection voltage detected by the first detector 135a provided at the subsequent stage of the first IF unit 132a. Based on the second detection voltage detected by the second detector 135b provided at the subsequent stage of the IF unit 132b, a signal from the active system unit 130-1A is output or a signal from the standby system unit 130-1B Is included in the determination unit 136 for determining whether to output. Therefore, the signal processing devices 130-1,..., 130-n of the present embodiment can monitor reception abnormality of only a desired channel from reception signals including signals of a plurality of channels. The receiving system can be switched.

  Further, the signal processing devices 130-1,..., 130-n of the present embodiment are based on the detected voltage detected by the first detector 135a and the second detector 135b, and the active system unit 130-1A. In addition to determining whether to output a signal from the standby system unit 130-1B or to output a signal from the standby system unit 130-1B, the automatic gains of the amplifiers provided in the working system unit 130-1A and the standby system unit 130-1B, respectively Since the control is performed, not only the number of components is reduced, but also the determination of system switching can be made based on the signal level after the automatic gain control is performed. In other words, when the signal level at the input stage of the receiving apparatus 100 is monitored, path switching has been performed even when signal level fluctuations can be absorbed by signal level control of automatic gain control. In the signal processing devices 130-1,..., 130-n of the embodiment, absorption up to the control limit in automatic gain control is possible by signal level control of automatic gain control.

  In the receiving apparatus 100 of the present embodiment, when a signal input to the first distributor 121 and a signal input to the second distributor 122 are signals transmitted from different transmitting stations, one transmission is performed. It is possible to detect the stop of the signal transmitted from the station and switch the receiving system. In addition, in the receiving apparatus 100 of the present embodiment, when the signal input to the first distributor 121 and the signal input to the second distributor 122 are signals transmitted from the same transmitting station, Since the end of broadcasting can be detected, unnecessary switching of the receiving system is prevented.

  As can be seen from a comparison between FIG. 18 and FIG. 2, the receiving apparatus 100 according to the embodiment of the present invention does not have a configuration corresponding to the input system switching unit 510 in the comparative example. Therefore, the amplifier 11 and the amplifier 21 in FIG. 2 only have to perform loss compensation up to the distributor 121, and it is not necessary to compensate for loss generated in the input system switching unit 510 as in FIG. Therefore, the gain performance required in the amplifier 11 and the amplifier 21 in the configuration of FIG. 2 is relaxed compared to the case of the configuration of FIG.

  In the present embodiment, since the up converter 134 is provided in the subsequent stage of the switch 137, the up converter can be shared by the active system and the standby system, which is preferable.

(Application 1)
Here, an application example of the first embodiment of the present invention described above will be described. In the application examples described below, the configurations of the signal processing device and the receiving device are the same as those in the first embodiment described above, and therefore, the same reference numerals are used and description thereof is omitted.

  FIG. 6 is a diagram illustrating an application example in which the active system and the standby system each include a plurality of antennas. As shown in FIG. 6, in this application example, the first working antenna 30 and the second working antenna 40 are connected to the working system, and the first working antenna 50 and the second working antenna 40 are connected to the working system. An antenna 60 is connected.

  The RF signals output from the first working antenna 30 and the second working antenna 40 are amplified by the first preamplifier 31 and the second preamplifier 41, respectively, and then mixed by the mixer 32, so that the first distributor 121 is input. Similarly, the RF signals output from the first spare antenna 50 and the second spare antenna 60 are amplified by the third preamplifier 51 and the fourth preamplifier 61, respectively, and then mixed by the mixer 52. To the distributor 122.

  When the installation location of the first active antenna 30 and the second active antenna 40 and the installation location of the first standby antenna 50 and the second standby antenna 60 are separated from the receiving apparatus 100, the mixer 32 and the second It is preferable to provide an amplifier for compensating transmission loss between the first distributor 121 and between the mixer 52 and the second distributor 122. In the example shown in FIG. 6, the installation location of the first active antenna 30 and the second active antenna 40 is close to the receiving device 100, and the installation location of the first standby antenna 50 and the second standby antenna 60 is the receiving device. The amplifier 53 is provided only between the mixer 52 and the second distributor 122, assuming a case away from 100. That is, in the configuration shown in FIG. 6, the installation location of the first active antenna 30 and the second active antenna 40 is separated from the installation location of the first standby antenna 50 and the second standby antenna 60. Assumed.

  The first working antenna 30 and the second working antenna 40 are set to receive different radio waves from different transmitting stations. Similarly, the first spare antenna 50 and the second spare antenna 60 are set to receive different radio waves from different transmitting stations. On the other hand, the first working antenna 30 and the first spare antenna 50 receive the same content broadcast, and the second working antenna 40 and the second spare antenna 60 receive the same content broadcast. And

  When the signal processing devices 130-1,..., 130-n and the receiving device 100 according to the first embodiment of the present invention are applied to the above situation, a reception abnormality of only some channels is detected. Since it is possible to switch the reception system of only the channel, for example, even when an abnormality occurs in the first working antenna 30, only reception from the first working antenna 30 is performed as the first spare antenna. It is possible to switch to 50. For example, even when an abnormality occurs in the first preamplifier 31, only reception from the first working antenna 30 can be switched to the first spare antenna 50. In any case, since it is not necessary to switch the second working antenna 40, unnecessary antenna switching does not occur.

  Further, when the transmitting stations of the radio waves received by the first working antenna 30 and the first standby antenna 50 are different, the signal processing devices 130-1, ..., 130 according to the first embodiment of the present invention. -N and the receiving device 100 are applied, it is possible to detect reception abnormalities in only some channels and switch the receiving system for only those channels. Only reception from the active antenna 30 can be switched to the first spare antenna 50. On the other hand, if the wave is stopped for a valid reason such as maintenance instead of a failure at the transmitting station, reception from the first working antenna 30 is not switched to the first standby antenna 50, so unnecessary antenna switching is performed. It never happens. Even in this case, since it is not necessary to switch the second working antenna 40, unnecessary antenna switching does not occur.

(Application example 2)
FIG. 7 is a diagram illustrating an application example in the case where a BS / CS antenna is provided in the active system and the standby system. As shown in FIG. 7, in this application example, a working antenna 70 for BS / CS is connected to the working system, and a spare antenna 80 for BS / CS is connected to the spare system.

  The working antenna 70 and the standby antenna 80 are antennas for receiving satellite broadcasts transmitted from broadcast satellites and communication satellites. Since satellite broadcasting has a very high frequency, if the signals received by the working antenna 70 and the standby antenna 80 are directly transmitted through a coaxial cable, the attenuation is very large. Therefore, the working antenna 70 and the spare antenna 80 are provided with converters 71 and 81 called LNB (Low Noise Block), convert the frequency into a frequency that can be passed through the coaxial cable, and transmit the received signal to the receiving device 100. .

  Further, the working antenna 70 and the spare antenna 80 are arranged at a distance. Even if the radio waves received by the active antenna 70 and the standby antenna 80 are radio waves transmitted from the same station (broadcast satellite or communication satellite), they may be affected by weather conditions such as rainfall at the receiving point. This phenomenon is called rain attenuation. Therefore, it is preferable that the working antenna 70 and the spare antenna 80 are arranged at a distance so as not to have the same weather conditions as much as possible.

  In the example shown in FIG. 7, it is assumed that the spare antenna 80 is arranged at a distance from the receiving device 100. Therefore, an electrical / optical (E / O) converter 82, an optical fiber 83, and an optical / electrical (O / E) converter 84 are provided in the middle of the transmission path from the standby antenna 80 to the receiving apparatus 100, and transmission loss is achieved. The signal attenuation due to is reduced.

  When the signal processing devices 130-1,..., 130-n and the receiving device 100 according to the first embodiment of the present invention are applied to the above situation, a reception abnormality of only some channels is detected. Since it is possible to switch the receiving system only for the channel, for example, even when a reception abnormality occurs only in the CS broadcast due to rain attenuation, only the reception of the CS broadcast from the active antenna 70 is sent to the standby antenna 80. It is possible to switch. When the configuration as in the above-described comparative example is adopted, the antenna cannot be switched until the overall signal level of the BS broadcast and the CS broadcast is lowered. Also, in the above situation, reception of BS broadcasts in which no abnormality is detected is not switched, so that unnecessary antenna switching does not occur.

  Furthermore, even in the situation where either BS broadcasting or CS broadcasting is stopped due to a valid reason such as maintenance of a broadcasting station or a broadcasting satellite or communication satellite entering the shadow of the moon or the earth, the first embodiment of the present invention is implemented. When the signal processing devices 130-1,..., 130-n and the receiving device 100 according to the embodiment are applied, it is possible to detect a reception abnormality of only a part of the channels and switch the receiving system of only the channels. As a result, unnecessary antenna switching does not occur. When the configuration as in the above-described comparative example is adopted, the stoppage of the BS broadcast or the CS broadcast may cause a decrease in the overall signal level, which may cause unnecessary antenna switching.

(Second Embodiment)
FIG. 8 is a diagram showing a schematic configuration of a signal processing device and a receiving device according to the second embodiment of the present invention. As illustrated in FIG. 8, the reception device 200 includes a distributor 221, signal processing devices 230-1 to 230-n, and a mixer 240. Note that n is an integer of 2 or more.

  The distributor 221 is a device for distributing the RF signal of the working system to each of the signal processing devices 230-1, ..., 230-n. In the configuration example shown in FIG. 8, the RF signal from the working antenna 10 is input to the distributor 221. However, as in the application example of the first embodiment, the signal input to the distributor 221 is not limited to the received signal from the antenna. The CATV system according to the present embodiment is not limited to the method of acquiring the received signal, but includes a receiving device 200 at the CATV head end and retransmits the received signal to a subscriber home device such as an image receiving device of each subscriber. Any system can be used. In this configuration example, the RF signal input from the working antenna 10 is amplified by the amplifier 11 provided in the transmission path on the way and input to the distributor 221.

  The signal processing devices 230-1,..., 230-n are so-called signal processors, and two systems of signals input to the input terminal of the working system section 230-1A and the input terminal of the standby system section 230-1B. After extracting a signal of a desired channel from each, a function of selecting a signal of one desired channel and retransmitting it from an output terminal is provided.

  The signal processing devices 230-1,..., 230-n described here can be used as, for example, an FM signal processor, an OFDM signal processor, a BS-IF signal processor, or a CS-IF signal processor. Since the configuration of the signal processing device 230-1 is a representative example, description of the configuration of the signal processing devices 230-2,..., 230-n will be omitted below.

  As shown in FIG. 8, the signal processing device 230-1 includes a first down converter 231a, a second down converter 231b, a first IF unit 232a, a second IF unit 232b, and a first branching device 233a. And a second branching device 233b, a first detector 235a, a second detector 235b, a determination unit 236, a switch 237, an upconverter 234, and a branching device 238. The signal processing device 230-1 includes an active system section 230-1A and a standby system section 230-1B, and includes a first down converter 231a, a first IF section 232a, a first branching device 233a, and a first The detector 235a belongs to the working system section 230-1A, and the second down converter 231b, the second IF section 232b, the second branching device 233b, and the second detector 235b are connected to the standby system section 230-1B. belong to.

  The signal output from the working system section 230-1A and the signal output from the standby system section 230-1B are switched by the switch 237, and after passing through the up converter 234, are output terminals of the signal processing device 230-1. To. Note that the switch 237 in the present embodiment is basically set to output the signal output from the working system section 230-1A to the up converter 234. A part of the RF signal output from the up-converter 234 is branched by the branching unit 238 and fed back as an input signal of the standby system unit 230-1B.

  The first down converter 231a converts the RF signal input to the working system section 230-1A into an intermediate frequency, and outputs the converted IF signal to the first IF section 232a. The first IF unit 232a includes an out-of-band removal filter and the like inside, and extracts a signal of a desired channel from the input IF signal. The out-of-band removal filter is configured by, for example, a surface acoustic wave filter or a bandpass filter, and extracts only a signal having a predetermined frequency included in a narrow band. Note that a typical method of using a filter is configured to extract only a single frequency. However, in a case where a plurality of frequencies are bundled to form one channel, the out-of-band removal filter can be used for a plurality of frequencies. This does not exclude the configuration for extracting the signal.

  The IF signal obtained by extracting only the signal of the desired channel by the first IF unit 232a is branched by the first branching device 233a, one is input to the switch 237, and the other is input to the first detector 235a. The The first detector 235a detects the signal level of the IF signal and outputs a first detection voltage. The first detection voltage is fed back to the AGC loop that automatically controls the gain of the amplifier provided in the first down converter 231a or the first IF unit 232a, and is input to the determination unit 236.

  Thus, in the working system section 230-1A, it is preferable to perform automatic gain control using the first detection voltage used in the determination section 236, because the circuit configuration can be simplified.

  Similarly, the second down converter 231b converts the RF signal input to the standby system section 230-1B into an intermediate frequency, and outputs the converted IF signal to the second IF section 232b. The second IF unit 232b includes an out-of-band removal filter or the like similar to that described above, and extracts a signal of a desired channel from the input IF signal. Here, the desired channel of the first IF unit 232a and the desired channel of the second IF unit 232b are the same channel.

  In the present embodiment, a part of the signal converted into the RF signal by the up-converter 234 is branched by the branching unit 238 and input to the standby system unit 230-1B. Therefore, the second down converter 231b performs frequency conversion so as to cancel the frequency conversion in the up converter 234. Since the frequency conversion in the up-converter 234 does not necessarily cancel out the frequency conversion in the first down-converter 231a, the frequency conversion amount in the first down-converter 231a and the second down-converter 231b is not necessarily the same. .

  The IF signal obtained by extracting only the signal of the desired channel by the second IF unit 232b is branched by the second branching device 233b, one is input to the switch 237, and the other is input to the second detector 235b. The As described above, the switch 237 in the present embodiment is basically set to output the signal output from the working system section 230-1A to the up converter 234. The second detector 235b detects the signal level of the IF signal and outputs a second detection voltage. The second detection voltage is fed back to the AGC loop that automatically controls the gain of the amplifier provided in the second down converter 231b or the second IF unit 232b, and is input to the determination unit 236.

  With the configuration described above, the determination unit 236 includes the signal level of the IF signal in the working system unit 230-1A detected by the first detector 235a and the standby system unit 230 detected by the second detector 235b. The signal level of the IF signal at -1B is input. Here, the signal level detected by the first detector 235a is the signal level of the IF signal in which only the signal of the desired channel is extracted by the first IF unit 232a, and the desired signal level in the RF signal input from the outside. The signal level of the channel. On the other hand, the signal level detected by the second detector 235b is the signal level of the IF signal obtained by extracting only the signal of the desired channel by the second IF unit 232b, and the desired channel in the RF signal output to the outside. The signal level is. That is, the determination unit 236 can monitor both the input signal and the output signal for the signal processing device 230-1.

  Here, the function of the determination unit 236 will be described in more detail. Note that the hardware configuration of the determination unit 236 is the same as that of the first embodiment, and thus the description thereof is omitted here.

  FIG. 9 is a block diagram illustrating the function of the determination unit 236. As shown in FIG. 9, the determination unit 236 includes a first comparison unit 236a, a second comparison unit 236b, a threshold setting unit 236c, and an abnormality determination unit 236d.

  The first comparison unit 236a compares the signal level detected by the first detector 235a with the threshold value for the working system, and determines whether the signal level of the input signal is High or Low with respect to the threshold value. It is configured to make a determination. Similarly, the second comparison unit 236b compares the signal level detected by the second detector 235b with the threshold value for the standby system, and the signal level of the output signal is high or low with respect to the threshold value. It is configured to determine whether there is any.

  The threshold setting unit 236c is a means for setting a threshold for the active system and a threshold for the standby system. The threshold value for the active system and the threshold value for the standby system may be different values. This is because the threshold for the working system is for monitoring the input signal, and the threshold for the standby system is the threshold for monitoring the output signal. The threshold setting unit 236c sets appropriate thresholds for the first detector 235a and the second comparison unit 236b.

  The abnormality determination unit 236d determines an abnormality in the input signal and the output signal based on the output of the first comparison unit 236a and the output of the second comparison unit 236b. When an abnormality is found in the input signal or the output signal, the abnormality determination unit 236d notifies the information to the outside, for example, and prompts an operator or the like to operate. In addition, when an abnormality is found only in the output signal, external notification may be made after trying to adjust the output level in the up-converter 234.

(Third embodiment)
FIG. 10 is a diagram showing a schematic configuration of a signal processing device and a receiving device according to the third embodiment of the present invention. As shown in FIG. 10, the receiving device 300 includes a first distributor 321, a second distributor 322, signal processing devices 330-1 to 330-n, and a mixer 340. . Note that n is an integer of 2 or more.

  The distributor 321 is a device for distributing the RF signal of the working system to each of the signal processing devices 330-1, ..., 330-n. In the configuration example shown in FIG. 10, the RF signal from the active antenna 10 is input to the first distributor 321, and the RF signal from the standby antenna 20 is input to the second distributor 322. However, as in the application example of the first embodiment, the signals input to the first distributor 321 and the second distributor 322 are not limited to signals received from the antenna. The CATV system of the present embodiment is not limited to the method of acquiring the received signal, but includes a receiving device 300 at the CATV head end, and retransmits the received signal to the subscriber home device such as the image receiving device of each subscriber. Any system can be used. In this configuration example, the RF signals input from the active antenna 10 and the standby antenna 20 are amplified by the amplifier 11 provided in the transmission path on the way, and are respectively the first distributor 321 and the second distributor. 322 is input.

  The signal processing devices 330-1,..., 330-n are so-called signal processors, and are two systems of signals input to the input terminal of the working system section 330-1A and the input terminal of the standby system section 330-1B. After extracting a signal of a desired channel from each, a function of selecting a signal of one desired channel and retransmitting it from an output terminal is provided.

  The signal processing devices 330-1,..., 330-n described here can be used as, for example, an FM signal processor, an OFDM signal processor, a BS-IF signal processor, a CS-IF signal processor, or the like. is there. The configuration of the signal processing device 330-1 is taken as a representative example, and the description of the configuration of the signal processing devices 330-2,.

  As shown in FIG. 10, the signal processing device 330-1 includes a first input switch 339a, a second input switch 339b, a first down converter 331a, a second down converter 331b, and a first IF. Unit 332a, second IF unit 332b, first branching device 333a, second branching device 333b, first detector 335a, second detector 335b, determination unit 336, switch 337, upconverter 334, A branching device 338a and a distributor 338b are provided. The signal processing device 330-1 includes an active system unit 330-1A and a standby system unit 330-1B, and includes a first down converter 331a, a first IF unit 332a, a first branching device 333a, and a first branching unit 333a. The detector 335a belongs to the working system section 330-1A, and the second down converter 331b, the second IF section 332b, the second branching device 333b, and the second detector 335b are connected to the standby system section 330-1B. belong to.

  The signal output from the active system section 330-1A and the signal output from the standby system section 330-1B are switched by a switch 337, and after passing through the up converter 334, are output terminals of the signal processing device 330-1. To. A part of the RF signal output from the up-converter 334 is branched by the branching device 338a and the distributor 338b, and is fed back to the first input switching device 339a and the second input switching device 339b.

  The first down-converter 331a converts the RF signal input from the first input switch 339a to the working system unit 330-1A into an intermediate frequency, and outputs the converted IF signal to the first IF unit 332a. . The first IF unit 332a includes an out-of-band removal filter and the like inside, and extracts a signal of a desired channel from the input IF signal. The out-of-band removal filter is configured by, for example, a surface acoustic wave filter or a bandpass filter, and extracts only a signal having a predetermined frequency included in a narrow band. Note that a typical method of using a filter is configured to extract only a single frequency. However, in a case where a plurality of frequencies are bundled to form one channel, the out-of-band removal filter can be used for a plurality of frequencies. This does not exclude the configuration for extracting the signal.

  The IF signal obtained by extracting only the signal of the desired channel by the first IF unit 332a is branched by the first branching device 333a, one is input to the switch 337, and the other is input to the first detector 335a. The The first detector 335a detects the signal level of the IF signal and outputs a first detection voltage. The first detection voltage is fed back to the AGC loop that automatically controls the gain of the amplifier provided in the first down converter 331a or the first IF unit 332a, and is input to the determination unit 336.

  Thus, in the working system section 330-1A, it is preferable to perform automatic gain control using the first detection voltage used in the determination section 336, since the circuit configuration can be simplified.

  Similarly, the second down converter 331b converts the RF signal input from the second input switch 339b to the standby system unit 330-1B into an intermediate frequency, and converts the converted IF signal to the second IF unit 332b. Output to. The second IF unit 332b includes an out-of-band removal filter and the like similar to the above, and extracts a signal of a desired channel from the input IF signal. Here, the desired channel of the first IF unit 332a and the desired channel of the second IF unit 332b are the same channel.

  The IF signal obtained by extracting only the signal of the desired channel by the second IF unit 332b is branched by the second branching device 333b, one is input to the switch 337, and the other is input to the second detector 335b. The The second detector 335b detects the signal level of the IF signal and outputs a second detection voltage. The second detection power is fed back to the AGC loop that automatically controls the gain of the amplifier provided in the second down converter 331b or the second IF unit 332b, and is input to the determination unit 336.

  As described above, the standby system unit 330-1B is also preferable because the circuit configuration can be simplified by performing the automatic gain control using the second detection voltage used in the determination unit 336.

  In the present embodiment, a part of the signal converted into the RF signal by the up-converter 334 is branched by the branching device 338a and the distributor 338b, and the first input switching device 339a and the second input switching device 339b Has been returned to. Depending on the switching state of the first input switch 339a and the second input switch 339b, the RF signal frequency-converted by the up converter 334 is input to the first down converter 331a and the second down converter 331b. The Therefore, when the RF signal frequency-converted by the up-converter 334 is input to the first down-converter 331a, the first down-converter 331a performs frequency conversion so as to cancel the conversion in the up-converter 334, and the up-converter When the RF signal frequency-converted in 334 is input to the second down converter 331b, the second down converter 331b performs frequency conversion so as to cancel the conversion in the up converter 334.

  Here, the frequency conversion in the up-converter 334 does not necessarily cancel out the frequency conversion in the first down-converter 331a and the second down-converter 331b. Therefore, depending on the switching state of the first input switch 339a and the second input switch 339b, the frequency conversion amounts in the first down converter 331a and the second down converter 331b are not necessarily the same. On the other hand, depending on the switching state of the first input switch 339a and the second input switch 339b, the frequency conversion amounts in the first down converter 331a and the second down converter 331b are the same. Accordingly, the frequency conversion amount in the first down converter 331a and the second down converter 331b can be made variable in conjunction with the switching state of the first input switch 339a and the second input switch 339b. Has been.

  With the configuration described above, the determination unit 336 includes the signal level of the IF signal in the working system unit 330-1A detected by the first detector 335a and the standby system unit 330 detected by the second detector 335b. The signal level of the IF signal at -1B is input. Here, the signal level detected by the first detector 335a depends on the switching state of the first input switch 339a, and the signal level of the desired channel in the RF signal for the working system and the RF signal output to the outside. The signal level of the desired channel is switched between two types. The signal level detected by the second detector 335b depends on the signal level of the desired channel in the RF signal for the standby system and the RF signal output to the outside depending on the switching state of the second input switch 339b. The signal level of the desired channel is switched in two ways. Therefore, the determination unit 336 can monitor three signals, that is, an input signal for the working system, an input signal for the standby system, and an output signal.

  Here, the function of the determination unit 336 will be described in more detail. Note that the hardware configuration of the determination unit 336 is the same as that of the first embodiment, and thus the description thereof is omitted here.

  FIG. 11 is a block diagram illustrating the function of the determination unit 336. As shown in FIG. 11, the determination unit 336 includes a first comparison unit 336a, a second comparison unit 336b, a threshold setting unit 336c, and a switch control unit 336d.

  The first comparison unit 336a compares the signal level detected by the first detector 335a with the threshold value for the working system, and the signal level of the working system or the signal level of the output signal is High with respect to the threshold value. Or Low. Similarly, the second comparison unit 336b compares the signal level detected by the second detector 335b with the threshold for the standby system, and the signal level of the standby system or the signal level of the output signal is compared with the threshold. It is configured to determine whether it is High or Low.

  The threshold setting unit 336c is means for setting a threshold for the active system and a threshold for the standby system. The threshold for the active system and the threshold for the standby system may be different depending on the switching state of the first input switch 339a and the second input switch 339b. As described above, the signal level detected by the first detector 335a is output to the outside with the signal level of the desired channel in the RF signal for the working system, depending on the switching state of the first input switch 339a. The signal level of the desired channel in the RF signal is switched in two ways, and the signal level detected by the second detector 335b depends on the switching state of the second input switch 339b in the RF signal for the standby system. This is because the signal level of the desired channel and the signal level of the desired channel in the RF signal output to the outside are switched in two ways. Therefore, the threshold setting unit 336c can be configured to change the threshold for the working system and the threshold for the standby system according to the switching state of the first input switch 339a and the second input switch 339b. .

  Based on the output of the first comparison unit 336a and the output of the second comparison unit 336b, the switch control unit 336d determines whether the switch 337, the first input switch 339a, and the second input switch 339b Perform switching control. That is, the switch control unit 336d dynamically selects the optimum input signal and output signal based on the results of monitoring the three signals of the input signal for the working system, the input signal for the standby system, and the output signal. To do. An example of an algorithm for switching control performed by the switch controller 336d will be described in detail later.

  Further, when the switch control unit 336d cannot select the optimum input signal and output signal based on the output of the first comparison unit 336a and the output of the second comparison unit 336b, for example, the information is externally transmitted. To prompt the operator. Further, when an abnormality is found only in the output signal, it is possible to design so that external notification is performed after the adjustment of the output level in the up-converter 334 is attempted.

  Next, an example of a signal path pattern by switching the switch 337, the first input switch 339a, and the second input switch 339b will be described with reference to FIGS. FIG. 12 is a diagram showing signal path patterns by switching the switch 337, the first input switch 339a, and the second input switch 339b. FIGS. 13 to 16 show the signal paths in each pattern. It is the figure shown typically.

  In this example, as shown in FIG. 12, the signal processing device 330-1 according to the present embodiment is in accordance with the switching state of the input signals selected by the first input switch 339 a and the second input switch 339 b. , Patterns 1 to 4 have signal paths. Here, the switching state of the input signal in the first input switching unit 339a includes the RF IN1 side and the output side of the up-converter 334, and the switching state of the input signal in the second input switching unit 339b is RF IN2. And the up-converter 334 output side, and the switching state of the input signal in the switch 337 includes the active system section 330-1A output side and the standby system section 330-1B output side. RF IN1 and RF IN2 are input terminals for the working system and the standby system, respectively, as shown in FIGS.

  As shown in FIGS. 12 and 13, in the signal path of pattern 1, the first input switch 339a selects the input signal on the RF IN1 side, and the second input switch 339b is on the output side of the up converter 334. The input signal is selected, and the switch 337 selects the input signal on the output side of the working system section 330-1A.

  As a result, as shown in FIG. 13, the input signal for the working system input from the RF IN1 passes through the first input switch 339a and is input to the working system section 330-1A. In the working system section 330-1 </ b> A, the input signal for the working system is detected, and the detection result is input to the determination section 336. Thereafter, the input signal for the working system output from the working system unit 330-1A passes through the switch 337, is frequency-converted by the up-converter 334, and then is output from RF OUT.

  Further, part of the output signal output from the up-converter 334 is branched by the branching device 338a and the distributor 338b and input to the second input switching device 339b. The output signal input to the second input switch 339b passes through the second input switch 339b and is input to the standby system unit 330-1B. In backup system section 330-1 </ b> B, the output signal is detected, and the detection result is input to determination section 336.

  As can be seen from the signal path, in the signal path of pattern 1, the detection result of the working system input signal and the output signal is input to the determination unit 336. Therefore, in the signal path of pattern 1, the determination unit 336 can monitor an abnormality in the input signal and output signal for the working system.

  As shown in FIGS. 12 and 14, in the signal path of pattern 2, the first input switch 339a selects the input signal on the output side of the up-converter 334, and the second input switch 339b is on the RF IN2 side. The input signal is selected, and the switch 337 selects the input signal on the output side of the standby system unit 330-1B.

  As a result, as shown in FIG. 14, the input signal for the standby system input from RF IN2 passes through the second input switch 339b and is input to the standby system unit 330-1B. In standby system section 330-1 </ b> B, the input signal for the standby system is detected, and the detection result is input to determination section 336. Thereafter, the standby system input signal output from the standby system unit 330-1B passes through the switch 337, is frequency-converted by the up-converter 334, and is output from RF OUT.

  Further, part of the output signal output from the up-converter 334 is branched by the branching device 338a and the distributor 338b and input to the first input switching device 339a. The output signal input to the first input switch 339a passes through the first input switch 339a and is input to the working system section 330-1A. In working system section 330-1 </ b> A, the output signal is detected, and the detection result is input to determination section 336.

  As understood from the signal path, in the signal path of pattern 2, the detection result of the standby system input signal and the output signal is input to the determination unit 336. Therefore, in the signal path of pattern 2, the determination unit 336 can monitor an abnormality in the input signal and the output signal for the standby system.

  As shown in FIGS. 12 and 15, in the signal path of pattern 3, the first input switch 339a selects the input signal on the RF IN1 side, and the second input switch 339b is the input signal on the RF IN2 side. The switch 337 selects the input signal on the output side of the working system unit 330-1A.

  As a result, as shown in FIG. 15, the input signal for the working system input from RF IN1 passes through the first input switch 339a and is input to the working system section 330-1A. In the working system section 330-1 </ b> A, the input signal for the working system is detected, and the detection result is input to the determination section 336. Thereafter, the input signal for the working system output from the working system unit 330-1A passes through the switch 337, is frequency-converted by the up-converter 334, and then is output from RF OUT.

  On the other hand, the input signal for the standby system input from the RF IN2 passes through the second input switch 339b and is input to the standby system unit 330-1B. In standby system section 330-1 </ b> B, the input signal for the standby system is detected, and the detection result is input to determination section 336. Note that the input signal for the standby system output from the standby system unit 330-1B cannot pass through the switch 337, and therefore is not output from RF OUT in the signal path.

  As can be seen from the signal path, in the signal path of pattern 3, detection results of the active system input signal and the standby system input signal are input to the determination unit 336. Therefore, in the signal path of pattern 3, the determination unit 336 can monitor an abnormality in the input signal for the working system and the input signal for the standby system.

  12 and 16, in the signal path of pattern 4, the first input switch 339a selects the input signal on the RF IN1 side, and the second input switch 339b is the input signal on the RF IN2 side. The switch 337 selects the input signal on the output side of the standby system unit 330-1B.

  As a result, as shown in FIG. 16, the input signal for the standby system input from RF IN2 passes through the second input switch 339b and is input to the standby system unit 330-1B. In standby system section 330-1 </ b> B, the input signal for the standby system is detected, and the detection result is input to determination section 336. Thereafter, the standby system input signal output from the standby system unit 330-1B passes through the switch 337, is frequency-converted by the up-converter 334, and is output from RF OUT.

  On the other hand, the input signal for the working system input from the RF IN1 passes through the first input switch 339a and is input to the working system section 330-1A. In the working system section 330-1 </ b> A, the input signal for the working system is detected, and the detection result is input to the determination section 336. Note that the input signal for the working system output from the working system unit 330-1A cannot pass through the switch 337, and therefore is not output from RF OUT in the signal path.

  As can be seen from the signal path, in the signal path of pattern 4, detection results of the active system input signal and the standby system input signal are input to the determination unit 336. Therefore, in the signal path of pattern 4, the determination unit 336 can monitor an abnormality in the input signal for the working system and the input signal for the standby system.

  Next, an example of the signal path switching algorithm of the patterns 1 to 4 will be described with reference to FIG. FIG. 17 is a flowchart showing the signal path switching algorithm. Note that the algorithm shown in FIG. 17 is an example of signal path switching, and other algorithms can be used depending on the operation policy of the apparatus.

  As shown in FIG. 17, first, the switch controller 336d controls switching between the first input switch 339a, the second input switch 339b, and the switch 337, thereby realizing the signal path of pattern 1 ( Step S1). As described above, the signal path of pattern 1 is for monitoring an abnormality in the input signal and output signal for the working system.

  Next, in the state of the signal path of pattern 1, the determination unit 336 determines whether an abnormality has occurred in the input signal for the working system (step S2). When there is no abnormality in the input signal for the working system (step S2; No), the input signal for the working system is monitored with the signal path of the pattern 1 until the abnormality occurs in the input signal for the working system. Continue.

  When an abnormality has occurred in the input signal for the working system (step S2; Yes), the switch controller 336d switches the input signal of the second input switch 339b to the RF IN2 side, and the signal path of pattern 3 is changed. Realize (Step S3). As described above, the signal path of the pattern 3 is for monitoring an abnormality in the input signal for the working system and the input signal for the standby system.

  Next, in the state of the signal path of pattern 3, the determination unit 336 determines whether an abnormality has occurred in the input signal for the standby system (step S4). When an abnormality has occurred in the input signal for the standby system (step S4; Yes), since an abnormality has occurred in both the input signal for the active system and the input signal for the standby system, the switch controller 336d gives an external notification to prompt the operator's work (step S9), and ends the algorithm.

  On the other hand, when there is no abnormality in the input signal for the standby system (step S4; No), the switch controller 336d switches the input signal of the first input switch 339a to the output side of the up converter 334 and switches the switch. The input signal of the device 337 is switched to the output side of the standby system unit 330-1B to realize the signal path of pattern 2 (step S5). As described above, the signal path of pattern 2 is for monitoring an abnormality in the input signal and the output signal for the standby system.

  Thereafter, in the state of the signal path of pattern 2, the determination unit 336 determines whether an abnormality has occurred in the input signal for the standby system (step S6). When there is no abnormality in the input signal for the standby system (step S6; No), the input signal for the standby system is monitored with the signal path of the pattern 2 until the abnormality occurs in the input signal for the standby system. Continue.

  If an abnormality has occurred in the input signal for the standby system (step S6; Yes), the switch controller 336d switches the input signal of the first input switch 339a to the RF IN1 side, and the signal path of the pattern 4 is changed. Realize (Step S7). As described above, the signal path of the pattern 4 is for monitoring an abnormality in the input signal for the working system and the input signal for the standby system.

  Next, in the state of the signal path of pattern 4, the determination unit 336 determines whether or not an abnormality has occurred in the input signal for the working system (step S8). If an abnormality has occurred in the input signal for the working system (step S8; Yes), an abnormality has occurred in both the input signal for the working system and the input signal for the standby system. 336d gives an external notification to prompt the operator's work (step S9), and ends the algorithm.

  On the other hand, when there is no abnormality in the input signal for the standby system (step S8; No), the switch controller 336d switches the input signal of the second input switch 339b to the output side of the up converter 334 and switches the switch. The input signal of the device 337 is switched to the output side of the working system section 330-1A, and the signal path of pattern 1 is returned (step S1).

  According to the signal path switching algorithm described above, even when an input signal for the active system or an input signal for the standby system is generated, the input signals can be switched to each other and a period during which switching determination is not required ( In pattern 1 and pattern 2), the output signal can be monitored. Therefore, for example, it is possible to detect an abnormality in the output signal due to, for example, a switch failure or an up-converter failure. Thereby, monitoring with higher certainty than monitoring only the input signal is realized.

  As described above, the signal processing devices 330-1,..., 330-n according to the present embodiment can monitor both the input signal for the working system and the input signal for the standby system, In addition, when the switching determination is not required, for example, in the period when the switching determination is not required, the output signal can be monitored. Furthermore, since the signal processing devices 330-1,..., 330-n according to the present embodiment include all the configurations of the first embodiment, only the desired channel is received from the received signals including the signals of a plurality of channels. Since reception abnormality can be monitored, switching of an appropriate reception system can be performed for each channel.

  Similarly, since the signal processing devices 330-1,..., 330-n according to the present embodiment include all the configurations of the first embodiment, signals that can be absorbed by signal level control of automatic gain control. It is possible to make a switching decision after absorbing the fluctuation of the level by the signal level control of the automatic gain control until the control limit in the automatic gain control.

  In addition, the receiving device 300 using the signal processing devices 330-1,..., 330-n according to the present embodiment also has the same effects as the receiving device 100 according to the first embodiment.

  In addition, in this embodiment, the structure which has only one among the 1st or 2nd input switching devices is also considered. For example, as a modification of the present embodiment, the input switch 339b is arranged in the previous stage of the standby system section, and a part of the RF signal output from the up converter 334 is branched by the branching device 338a, so that the second input switching is performed. A configuration for returning to the device 339b is also conceivable. By adopting such a configuration, for example, when the input signal of the second input switch 339b is switched to the RF IN2 side, the same effect as the receiving device 100 according to the first embodiment can be obtained. When the input signal of the second input switch 339b is switched to the output side of the up-converter 334, the same effect as that of the receiving device 200 according to the second embodiment can be obtained.

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above embodiments. What was comprised combining each component mentioned above suitably is also contained in this invention. Further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made.

100, 200, 300 Receivers 121, 321 First distributor 122, 322 Second distributor 130-1,..., 130-n, 230-1, ..., 230-n, 330-1 ,..., 330-n Signal processor 130-1A, 230-1A, 330-1A Working system section 130-1B, 230-1B, 330-1B Standby system section 131a, 231a, 331a First down converter 131b , 231b, 331b Second down converters 132a, 232a, 332a First IF units 132b, 232b, 332b Second IF units 133a, 233a, 333a First branch units 133b, 233b, 333b Second branch unit 134 , 234, 334 Upconverters 135a, 235a, 335a First detectors 135b, 235b, 335b Detector 136 determining unit 1361 first comparator 1362 second comparator 1363 first variable power supply 1364 second variable power supply 1365 CPU of
1366 Memory 136a First comparison unit 136b Second comparison unit 136c Threshold setting unit 136d Switch control unit 137, 237, 337 Switcher 140, 240, 340 Mixer 221 Distributor 238, 338a Branch unit 338b Distributor 339a First 1 input switch 339b second input switch 500 receiving device 510 input system switching unit 511, 512 branching device 513, 514 detector 515 determination unit 516 switching device 520 distributor 530-1, ..., 530-n Signal processor 531 Down converter 532 IF unit 533 Branch 534 Up converter 535 Detector 540 Mixer 10 Active antenna 11 Amplifier 20 Spare antenna 21 Amplifier 30 First active antenna 31 First preamplifier 32 Mixer 40 Second active Antenna 41 Second preamplifier 50 First Preliminary antenna 51 third preamplifier 52 mixer 53 amplifier 60 second preliminary antenna 61 fourth preamplifier 70 working antenna 71, 81 converter (LNB)
80 Spare antenna 82 E / O converter 83 Optical fiber 84 O / E converter 1 CATV system 2 CATV station 3 CATV head end 4 Signal transmission path 5 Subscriber home 6 Subscriber home equipment 7, 8 Transmitting station

Claims (9)

A first down converter that converts an input high frequency signal into an intermediate frequency signal, a first IF unit that extracts a signal of a desired channel from the intermediate frequency signal, and a first IF unit that is provided after the first IF unit. A working system unit having a first detection unit that outputs a detection voltage;
A second down converter for converting an input high frequency signal into an intermediate frequency signal, a second IF unit for extracting the signal of the desired channel from the intermediate frequency signal, and a second stage of the second IF unit; A standby system unit having a second detection unit that outputs the second detection voltage;
An up-converter unit that converts an intermediate frequency signal output from either the active system unit or the standby system unit into a high-frequency signal and outputs the high-frequency signal;
A branching part for branching a part of the high-frequency signal output by the up-converter part;
With
A part of the high-frequency signal branched by the branching unit is input to either the working system unit or the standby system unit. A first down converter that converts an input high frequency signal into an intermediate frequency signal, a first IF unit that extracts a signal of a desired channel from the intermediate frequency signal, and a first IF unit that is provided after the first IF unit. A working system unit having a first detection unit that outputs a detection voltage;
A second down converter for converting an input high frequency signal into an intermediate frequency signal, a second IF unit for extracting the signal of the desired channel from the intermediate frequency signal, and a second stage of the second IF unit; A standby system unit having a second detection unit that outputs the second detection voltage;
An up-converter unit that converts an intermediate frequency signal output from either the active system unit or the standby system unit into a high-frequency signal and outputs the high-frequency signal;
A branching part for branching a part of the high-frequency signal output by the up-converter part;
A distributing unit that distributes the high-frequency signal branched by the branching unit into a first high-frequency signal and a second high-frequency signal;
A first input switching unit that selects one of the first high-frequency signal and an externally input high-frequency signal and outputs the selected signal to the working system unit;
A second input switching unit that selects one of the second high-frequency signal and a high-frequency signal input from the outside and outputs the selected signal to the standby system unit;
A switching unit that selects one of the intermediate frequency signal input from the active system unit and the intermediate frequency signal input from the backup system unit and outputs the selected signal to the up-converter;
With
At least one of the first input switching unit and the second input switching unit inputs a high-frequency signal input from the outside to the working system unit or the standby system unit. A determination unit that controls the first input switching unit, the second input switching unit, and the switching unit based on the first detection voltage and the second detection voltage;
The signal processing apparatus according to claim 2 , further comprising: A plurality of the signal processing devices according to any one of claims 1 to 3 ,
A first distribution unit that distributes a signal of the working system to an input terminal of each of the working system units of each of the signal processing devices; and a signal of a backup system that is distributed to the input terminals of each of the standby system units of the signal processing device. A second distribution unit and a mixing unit for mixing signals output from the output terminals of the signal processing device;
A receiving apparatus comprising: A signal inputted to the first distribution unit, the and the second signal input to the distribution unit, according to claim 4, characterized in that it is configured to be a signal sent from different stations The receiving device described in 1. The signal input to the first distribution unit and the signal input to the second distribution unit are configured to be signals transmitted from the same transmitting station. 5. The receiving device according to 4 . The signal input to the first distribution unit and the signal input to the second distribution unit are configured to include signals transmitted from different transmitting stations, respectively. Item 5. The receiving device according to Item 4 . Claim 4 and receiving apparatus according to any one of the ~ 7, CATV headend, characterized in that it comprises a transmission device for transmitting a signal output from the receiving device. 9. A CATV head end according to claim 8 , a signal transmission path for transmitting a signal transmitted from the CATV head end, and a subscriber premises apparatus for receiving a signal transmitted via the signal transmission path. CATV system characterized by this.

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