JP4674185B2 - booster - Google Patents

Description

  The present invention relates to a booster used in a GPS signal transmission system that enables reception of a GPS signal even within a radio wave blocking body in which the GPS signal is difficult to arrive inside.

  An example of the system described above is disclosed in Patent Document 1. In the technique disclosed in this document 1, a GPS signal received by one GPS signal antenna and a BS broadcast signal are combined and transmitted to a transmission path. It is divided into a BS broadcast signal and a GPS signal by a distributor provided in the transmission path. The BS signal is supplied from the distributor to the BS tuner. A terminal is provided to receive the GPS signal from the distributor, and the GPS signal output from the terminal is supplied to the transmitter and transmitted.

JP 2005-244625 A

  Using the technology disclosed in Patent Document 1, for example, if a GPS signal antenna is installed on the roof of a building and a transmitter is installed inside the building, GPS signals can be received even in buildings where radio waves are unlikely to arrive. can do. Therefore, by receiving the GPS signal using the GPS receiver in the building, the user of the GPS receiver can know the position of the building. By the way, it may be desirable to amplify the BS broadcast signal transmitted through the transmission path before supplying it to the BS tuner. Moreover, when transmitting a GPS signal, it may be desirable to maintain the level at a predetermined level. These points are not considered in Patent Document 1.

  An object of this invention is to provide the booster which can amplify a broadcast signal and a GPS signal to an appropriate level by one unit.

  A booster according to one aspect of the present invention includes a demultiplexing unit provided in a transmission path through which a combined signal of a GPS signal received by a GPS receiving antenna and a broadcast signal received by a broadcast receiving antenna is transmitted. Yes. The demultiplexing means is preferably provided in the transmission path. The demultiplexing means demultiplexes the GPS signal and the broadcast signal. The demultiplexed broadcast signal is amplified by the broadcast signal amplification means and supplied to the reception means connection terminal. The demultiplexed GPS signal is amplified by the GPS signal amplifying means and supplied to the GPS signal retransmission antenna. The GPS signal amplification means is automatically gain-controlled so that the transmission output from the GPS signal retransmission antenna is at a predetermined level.

  In the booster configured as described above, since the broadcast signal is amplified by the broadcast signal amplifying means and supplied to the receiving means connection terminal, a broadcast signal of an appropriate level is supplied to the receiving means. Furthermore, since the GPS signal is amplified by the GPS signal amplifying means controlled automatically and supplied to the GPS signal retransmission antenna, the GPS signal can be retransmitted at a required level.

  The booster according to another aspect of the present invention includes a demultiplexing unit provided in the transmission line. The transmission path includes a radio frequency blocker, for example, a frequency-converted GPS signal obtained by frequency-converting GPS signals received by a plurality of GPS receiving antennas provided at different positions outside buildings, subways, and underground shopping streets to different frequencies. A combined signal obtained by combining the broadcast signal received by the broadcast receiving antenna is transmitted. This transmission path is laid to a position in the radio wave blocking body corresponding to each GPS receiving antenna. At each of these positions, a plurality of GPS signal retransmission antennas are installed. At these positions, the demultiplexing means re-frequency-converts the frequency-converted GPS signal corresponding to the GPS signal received by the GPS receiving antenna corresponding to the position among the frequency-converted GPS signals in the synthesized signal. The re-frequency converted GPS signal and the broadcast signal are demultiplexed. The demultiplexed broadcast signal is amplified by the broadcast signal amplification means and supplied to the reception means connection terminal. The demultiplexed re-frequency converted GPS signal is amplified by the GPS signal amplifying means and supplied to the corresponding GPS signal retransmission antenna. The GPS signal amplifying means is automatically gain-controlled so that the transmission output from the corresponding GPS signal retransmission antenna becomes a predetermined level.

  GPS signals received by GPS receiving antennas provided at a plurality of positions outside the radio wave blocking body are retransmitted by retransmission antennas corresponding to the GPS receiving antennas in the radio wave blocking body. At the time of this re-transmission, the booster according to another aspect of the present invention transmits the re-transmission credit GPS signal with automatic gain control so that the transmission output from the GPS signal re-transmission antenna becomes a predetermined level. Further, the broadcast signal is also amplified to an appropriate level and supplied to the receiving means.

  As described above, according to the present invention, it is possible to amplify broadcast signals and GPS signals to an appropriate level while using a single booster, and to reduce costs.

  As shown in FIGS. 1A to 1C, the GPS signal transmission system according to the first embodiment of the present invention is a radio wave blocking body that is difficult to receive radio waves directly inside, for example, the outside of a building 2, such as a rooftop. A plurality of, for example, eight GPS receiving antennas 4a to 4h are arranged in 2R. These GPS receiving antennas 4a to 4h are arranged at different positions. GPS retransmission antennas 6a to 6h are arranged on the ceiling of each floor in the building 2, respectively. These GPS retransmission antennas 6a to 6h are arranged at positions corresponding to the GPS reception antennas 4a to 4h, respectively. That is, each GPS retransmission antenna 6a is disposed at the same latitude and longitude position as the GPS reception antenna 4a, and each GPS retransmission antenna 6b is disposed at the same latitude and longitude position as the GPS reception antenna 6b. The same applies to the other GPS retransmission antennas 6c to 6h.

  When the GPS signals received by the GPS receiving antennas 4a to 4h are transmitted from the corresponding GPS retransmission antennas 6a to 6h, for example, the GPS signals received by the GPS receiving antenna 4a are transmitted from the GPS retransmission antennas 6a,. -When the GPS signal received by the GPS antenna 4h is retransmitted from each GPS retransmission antenna 6h, the GPS receiver (not shown) carrying person at each floor of the building 2 can select one of the GPS retransmission antennas 6a to 6h. Depending on whether the GPS signal being retransmitted is received, it is possible to know in which position of the building 2 the carrier is located.

  However, the GPS signals received by the GPS receiving antennas 4a to 4h have the same frequency, for example, 1.57542 GHz, as shown in FIG. Therefore, even if the GPS signals received by the GPS receiving antennas 4a to 4h are simply transmitted to the GPS retransmission antennas 6a to 6h and retransmitted from the retransmission antennas 6a to 6h, You cannot know the location. If each GPS receiving antenna 4a to 4h and each GPS retransmission antenna 6a to 6h are connected by individual transmission paths, the received signal of the GPS receiving antenna 4a is sent from the GPS retransmission antenna 6a to the GPS receiving antenna 4h. Since the received signal is reliably retransmitted from the GPS retransmission antenna 6h, the above problem is solved. However, the work of laying eight transmission lines separately on each floor is very troublesome.

  Therefore, each GPS signal received by each of the GPS receiving antennas 4a to 4h is converted into a frequency-converted GPS signal having a different frequency, for example, a GPS-converted signal as shown in FIG. It transmits through the transmission line. Each of the GPS retransmission antennas 6a to 6h selects a GPS conversion signal corresponding to itself, re-frequency converts this to the same frequency as the original GPS signal, and retransmits it.

  Therefore, in the head device shown in FIG. 3, each of the GPS receiving antennas 4a to 4h is provided with first frequency conversion means, for example, down converters 8a to 8h, and the GPS signals received by the corresponding GPS receiving antennas are converted into GPS converted signals. Frequency conversion. The respective GPS conversion signals from the down converters 8a to 8h are synthesized by a synthesizing means, for example, a synthesizer 10, and transmitted to one transmission line 12 constituted by, for example, a coaxial cable.

  As the transmission line 12, a transmission line used in the television joint reception system is used. This eliminates the need to install a transmission line separately from the transmission line for the television joint reception system. Accordingly, the broadcast signal, for example, the UHF television broadcast signal received by the UHF television broadcast receiving antenna 14, the VHF television broadcast signal received by the VHF television broadcast receiving antenna 16, and the BS satellite broadcast receiving antenna 18 is received. The satellite broadcast intermediate frequency signal that has been frequency-converted is mixed by the mixer 20 and further amplified by the amplifier 22 is also mixed by the mixer 24 into the transmission line 12.

  Since the transmission path 12 of the joint reception system is used in this way, the frequency band of the GPS conversion signal is a frequency band that can be transmitted through the transmission path 12 of the joint reception system, for example, UHF television as shown in FIG. A vacant frequency band between the broadcast frequency band and the satellite broadcast intermediate frequency band is used. Moreover, since such a vacant frequency band is utilized, the frequency of each GPS conversion signal is comparatively close.

  As shown in FIG. 4, each broadcast signal and GPS conversion signal transmitted through the transmission path 12 are branched at each floor by a branching unit, for example, one branching unit 26, and retransmitted by a distributing unit, for example, eight distributing unit 28. The signals are distributed so as to correspond to the antennas 6a to 6h and supplied to second frequency conversion means, for example, up-converters 30a to 30h, corresponding to the GPS retransmission antennas 6a to 6h, respectively. The up-converter 30a corresponds to the retransmission antenna 6a, and the up-converter 30h corresponds to the retransmission antenna 6h. The up-converters 30a to 30h correspond to each of the supplied GPS conversion signals, for example, the amplifier converter 30a has a GPS corresponding to the GPS signal received by the GPS receiving antenna 4a among the supplied GPS conversion signals. Select the converted signal and reconvert back to the original GPS signal. This reconverted GPS signal is referred to as a reconverted GPS signal. Each of the up converters 30a to 30h allows each broadcast signal to pass through.

  The reconverted GPS signals and broadcast signals from each of the up-converters 30a to 30h are amplified by boosters 32a to 32h, respectively, and the reconverted GPS signals are retransmitted from the corresponding GPS retransmission antenna. For example, the reconverted GPS signal from the up-converter 30a is amplified by the booster 32 and then retransmitted from the retransmission antenna 6a. Each broadcast signal is output from the booster 32 and supplied to receiving means, for example, a television receiver or a BS tuner.

  In each of the down converters 8a to 8h, as shown in FIGS. 5 and 6, the GPS signal input from the input terminal 32 is amplified by, for example, three-stage amplifiers 34a to 34c. Filters that extract GPS signals, for example, SAW filters 36a and 36b, are inserted between the amplifiers 34a to 34c, and unnecessary signals are removed. The output signal of the final stage amplifier 34 c is supplied to the mixer 38. A local oscillation signal is also supplied to the mixer 38. The mixer 38 frequency-converts the input GPS signal into a predetermined GPS conversion signal by using a local oscillation signal, and after unnecessary signals are removed by a filter, for example, a band pass filter 40, the level adjuster 42 is turned on. Amplified by amplifiers 44 and 46 provided between them and output from an output terminal 48.

  In order to perform frequency conversion in the mixer 38, a local oscillation signal is required. In order to generate the local oscillation signal, a so-called PLL oscillation circuit is used as the local oscillation means. That is, a voltage-controlled oscillator 50 that generates a local oscillation signal, a frequency divider 52 that divides the local oscillation signal by 1 / n, and a frequency-divided signal from the frequency divider 52 is divided by a frequency divider 54. A PLL circuit 56 for controlling the oscillation frequency of the voltage controlled oscillator 50 so as to match the signal is provided. The frequency divider 54 divides the reference signal by 1 / N. When the frequency division number n of the frequency divider 52 is appropriately selected, the voltage-controlled oscillator 50 generates a required local oscillation signal.

  By the way, in the PLL oscillation circuit, a reference signal is required as a frequency reference for generating a local oscillation signal. However, if a reference signal generated individually by each of the down converters 8a to 8h is used, the down converters 8a to 8h There is a possibility that deviation occurs in each reference signal. Since the frequencies of the GPS conversion signals of the down converters 8a to 8h are close to each other, in the worst case, the frequencies of these GPS conversion signals may partially overlap. In order to avoid this, all the down converters 8a to 8h need to use a common reference signal.

  Therefore, in this embodiment, as shown in FIG. 5, a reference oscillator 58 for generating a reference signal is provided only in the down converter 8a, and the reference signal is passed through a filter that passes only the reference signal, for example, the bandpass filter 60, After amplification by the amplifier 62, the signal is combined with the GPS conversion signal by a combining means, for example, a combiner 64, and supplied to the output terminal 48.

  The reference signal and the GPS conversion signal are supplied to the combiner 10 as shown in FIG. The synthesizer 10 has a two divider 64, and one of the divided signals is supplied to the bidirectional divider 68 via the branching filter 66 and is supplied to each of the down converters 8b to 8h.

  In each of the down converters 8b to 8h, as shown in FIG. 6, the reference signal and the GPS conversion signal supplied from the distributor 68 to the output terminal 48 are supplied from the branch terminal of the one branching device 70 to the amplifier 72 via the output terminal. And a reference signal is extracted by a filter, for example, a band pass filter 74, and supplied to the frequency divider 54. Therefore, the down converters 8a to 8h commonly use the reference signal of the reference oscillator 58 of the down converter 8a. Therefore, the frequencies of the GPS conversion signals from the respective down converters 8a to 8h do not overlap and maintain a predetermined frequency relationship.

  The GPS conversion signals from the down converters 8b to 8h are supplied from the branch terminals of the distributor 68 and the branching unit 66 shown in FIG. It is combined with a GPS conversion signal and a reference signal from a certain down converter 8 a and supplied to the combiner 24. That is, the reference signal is transmitted to the transmission path 12 together with the GPS conversion signals of the down converters 8a to 8h. Therefore, in this embodiment, the reference signal is selected to have a frequency lower than the VHF television broadcast frequency band, for example, as shown in FIG.

  As shown in FIG. 8, in each of the up-converters 30 a to 30 h, each GPS conversion signal, reference signal, and each broadcast signal are supplied to the input terminal 78, and these are supplied to the 2-distributor 80.

  One distribution output of the two distributor 80 is supplied to the one branching device 82, and the output is supplied to a filter, for example, a bandpass filter 84, that extracts a corresponding one-wave GPS conversion signal among the GPS conversion signals. The For example, the up-converter 30a extracts a GPS conversion signal obtained by frequency-converting the GPS signal received by the GPS receiving antenna 4a by the down-converter 8a. The one-wave GPS conversion signal extracted from the bandpass filter 84 is supplied to the amplifier 88 via the level adjuster 86, amplified there, and supplied to the mixer 90.

  On the other hand, the branch output of the single branching device 82 is supplied to a filter for extracting a reference signal, for example, a bandpass filter 92. The reference signal extracted by the band pass filter 92 is amplified by the amplifier 94, supplied to the frequency divider 96 of the local oscillating means, and divided by 1 / N. This frequency-divided signal is supplied to the PLL circuit 98, and the PLL circuit 98 controls the oscillation frequency of the voltage controlled oscillator 100 that generates the local oscillation signal. This control is performed so that the frequency-divided signal of the frequency divider 102 that divides the local oscillation signal by 1 / n1 matches the frequency-divided signal of the frequency divider 96. By appropriately selecting the frequency division number n1 of the frequency divider 102, the local oscillation signal is converted to a frequency required to re-frequency-convert the GPS conversion signal supplied to the mixer 90 to the same frequency as the original GPS signal. Frequency can be maintained. Moreover, in each of the up-converters 30a to 30h, since the reference signal generated by the down-converter 8a and used by the other down-converters 8b to 8h is used, the frequency of each re-frequency converted GPS signal is It becomes completely the same as the original GPS signal.

  The reconverted GPS signal output from the mixer 90 is amplified by an amplifier 108 having filters for removing unnecessary signals, for example, SAW filters 104 and 106 on the input side and the output side. The output signal of the SAW filter 106 at the subsequent stage is branched by the one branching device 110, the branch output is supplied to the detection circuit 112, the level is detected, and the level adjuster 86 outputs the level so that this level becomes a predetermined value. The level is adjusted. That is, automatic gain control is performed.

  On the other hand, the other distribution output of the distributor 80 is supplied to a filter that extracts each broadcast signal, for example, the bandpass filter 114. Each broadcast signal from the bandpass filter 114 is amplified by the amplifier 116, and then synthesized by the synthesizer 118 with the output of the one branching unit 110 (reconverted GPS signal), supplied to the output terminal 120, and boosters 32a to 32h. Are supplied to the corresponding ones.

  The output signals of the up-converters 30a to 30h, that is, the reconverted GPS signals and the broadcast signals are supplied to the input terminals 122 of the boosters 32a to 32h and are divided into two by the two distributors 124, as shown in FIG. . One distribution output of the two distributor 124 is supplied to a filter that extracts each broadcast signal, for example, a band-pass filter 126. Each broadcast signal output from the band-pass filter 126 is amplified by a plurality of stages, for example, three stages of amplifiers 128a to 128c, and supplied from the output terminal 130 to receiving means such as a BS tuner and a television receiver. Since the broadcast signals are amplified by the amplifiers 128a to 128c in this way, even if the broadcast signals are attenuated during transmission, the broadcast signals are supplied to the BS tuner and the television receiver at appropriate levels. .

  The other distribution output of the two distributor 124 is supplied to a filter that extracts a reconverted GPS signal, for example, a bandpass filter 132. The reconverted GPS signal extracted by the bandpass filter 132 is supplied to the input side of the three-stage amplifiers 136a, 136b, and 136c having a level adjuster 134 on the way and amplified. A part of the output of the intermediate-stage amplifier 136b among the three-stage amplifiers 136a to 136c is branched by the one-branch unit 138, and the branch output is supplied to the detector 140. In the detector 140, the level of the branch output is detected, and the level adjuster 134 is adjusted by the output signal of the detector 140 so that this level becomes a predetermined level. That is, automatic gain control is performed. The output signal of the final stage amplifier 136c is supplied to the corresponding one of the retransmission antennas 6a to 6h via the output terminal 142.

  The booster 32a to 32h and the up-converter 30a to 30h thus perform automatic level adjustment of the reconverted GPS signal because the transmission output from the GPS retransmission antennas 6a to 6h is determined by the Radio Law Enforcement Rules. This is because it can be used as a weak radio wave below the output power without a license.

  The band pass filters 126 and 132 function as a demultiplexing unit that demultiplexes the broadcast signal and the GPS signal.

  A second embodiment of the present invention is shown in FIG. In this embodiment, the trunk line of the transmission line is the optical transmission line 12a. Therefore, the broadcast signals, the GPS conversion signals, and the reference signals from the head device 142 including the down converters 8a to 8h, the combiner 10, the mixers 20, 24, and the amplifier 22 shown in FIG. For example, it is converted into an optical signal by the optical transmitter 144 and transmitted to the optical transmission line 12a. The optical signal is branched by the optical branching units 26a, 26a,... At the positions corresponding to the respective floors of the optical transmission line 12a. The branched optical signal is converted into an electrical signal, that is, each broadcast signal, each GPS converted signal, and a reference signal by an optical-electric conversion means, for example, an optical receiver 146, 146.・ ・ Supplied to Hereinafter, the same processing as in the first embodiment is performed.

  In this way, each broadcast signal, each GPS conversion signal, and reference signal are converted into optical signals, and these optical signals are transmitted to each floor by the optical transmission path 12a, so long-distance transmission of high-rise buildings and the like becomes possible. In addition, reliability is improved.

  In both the above embodiments, the number of GPS receiving antennas and GPS retransmitting antennas is eight, but can be arbitrarily changed as long as the number is two or more. In that case, the number of down-converters and up-converters is also increased or decreased according to the number of both antennas. In both the above-described embodiments, the frequency band of each GPS conversion signal is set between the UHF band and the frequency band of the satellite broadcast intermediate frequency signal. It can be a belt. In both the above-described embodiments, the transmission path of the television joint reception system is used as a transmission path for the GPS conversion signal. However, the present invention is not limited to this. For example, a transmission path dedicated to the GPS signal conversion signal is laid. It is also possible. In both the above embodiments, a building is used as a radio wave blocking body, but the building is not limited to this. For example, any area may be used as long as it is difficult to directly receive radio waves such as a subway premises, an underground mall, and a tunnel Can be used as a radio wave blocking body. In each of the above embodiments, the satellite broadcast intermediate frequency signal is included in the broadcast signal. Instead of or in addition to this, the satellite communication signal is received by the satellite communication reception antenna and converted into the satellite communication intermediate frequency signal. Can be used, and the independent broadcast signal in the joint reception system can also be included in the broadcast signal. In the above-described embodiment, the GPS signals received by the plurality of GPS receiving antennas are frequency converted and transmitted to the corresponding GPS retransmission antennas, where they are re-frequency converted to the original GPS signals. A GPS signal received by one GPS receiving antenna is transmitted along with a broadcast signal through a transmission line, a booster according to the present invention is installed at a position branched from the transmission line, the broadcast signal is amplified, and the television receiver or the like is installed. It can also be used when supplying and amplifying the GPS signal and supplying it to the GPS retransmission antenna.

It is a figure which shows arrangement | positioning of the GPS receiving antenna and GPS retransmission antenna of the GPS signal transmission system in which the booster of the 1st Embodiment of this invention is used. It is a figure which shows the frequency of each signal used with the GPS signal transmission system of FIG. It is a block diagram of the head apparatus of the GPS signal transmission system of FIG. It is a block diagram of each terminal of the GPS signal transmission system of FIG. It is a block diagram of the down converter 8a shown in FIG. FIG. 4 is a block diagram of down converters 8b to 8h shown in FIG. It is a block diagram of the combiner | synthesizer 10 shown in FIG. It is a block diagram of the down converters 30a thru | or 30h shown in FIG. It is a block diagram of the boosters 32a thru | or 32h shown in FIG. It is a block diagram of the GPS signal transmission system with which the booster of the 2nd Embodiment of this invention is used.

Explanation of symbols

2 Building (Radio wave blocking body)
4a to 4h GPS receiving antenna 6a to 6h GPS retransmission antenna 8a to 8h Down converter (first frequency converting means)
12 Transmission path 30a thru | or 30h Up converter (2nd frequency conversion means)
128a to 128c amplifier (broadcast signal amplification means)
136a to 136c Amplifier (GPS signal amplification means)
134 Level adjuster (automatic gain control means)
140 Detection circuit (automatic gain control means)

Claims (2)

A demultiplexer that is provided in a transmission path for transmitting a composite signal of the GPS signal received by the GPS receiving antenna and the broadcast signal received by the broadcast receiving antenna, and demultiplexes the GPS signal and the broadcast signal. Means,
Broadcast signal amplification means for amplifying the demultiplexed broadcast signal and supplying it to the reception means connection terminal;
GPS signal amplification means for amplifying the demultiplexed GPS signal and supplying it to a GPS signal retransmission antenna;
And the GPS signal amplifying means is a booster whose gain is automatically controlled so that the transmission output from the GPS signal retransmission antenna is at a predetermined level. A frequency-converted GPS signal obtained by frequency-converting GPS signals received by a plurality of GPS receiving antennas provided at different positions outside the radio wave blocking body to different frequencies, and a broadcast signal received by the broadcast receiving antenna Is transmitted to a plurality of GPS signal retransmission antennas installed corresponding to each of the GPS receiving antennas in the radio wave blocking body via the transmission path, and the combined signal is transmitted at these positions. Of the frequency-converted GPS signals in the signal, a re-frequency-converted GPS signal obtained by re-frequency-converting a frequency-converted GPS signal corresponding to the GPS signal received by the GPS receiving antenna corresponding to the position, and the broadcast signal And a demultiplexing means for demultiplexing,
Broadcast signal amplification means for amplifying the demultiplexed broadcast signal and supplying it to the reception means connection terminal;
GPS signal amplification means for amplifying the demultiplexed re-frequency converted GPS signal and supplying it to the corresponding GPS signal retransmission antenna;
And the GPS signal amplifying means is a booster whose gain is automatically controlled so that a transmission output from the corresponding GPS signal retransmission antenna becomes a predetermined level.

Images