JP6616890B2 - Receiving system - Google Patents

Description

  The present invention relates to a technique for diversity reception of a signal of a plurality of channels in a radio reception apparatus.

  For example, in a broadcasting system, video information captured by a camera or microphone of a mobile station and collected audio information are wirelessly transmitted to the base station device, and the base station device transmits the video / audio information to the broadcast station. The video / audio information is wirelessly transmitted as a broadcast signal to a general home. In the broadcasting industry in Japan, a base station device that relays video / audio information from a mobile station to a broadcast station is called a portable video / audio transmission device (hereinafter referred to as FPU: Field Pick-up Unit).

  FIG. 5 is a configuration diagram of a transmission / reception system according to the background art, and shows, for example, a system configuration of an FPU having a diversity function. For example, in an FPU used for a marathon relay, etc., video material shot with a relay station camera, which is a mobile station, is transmitted to a base station installed on a high place such as a mountain top or a rooftop of a building while moving the relay car. And transmitted from the base station to the broadcasting station. The relay vehicle is a transmission side, and includes a transmission control unit 11, an IF cable 12, a transmission high-frequency unit 13, and a transmission antenna 14. The base station is a receiving side, and includes receiving antennas 16a and 16b, a receiving high-frequency unit 17, an IF cable 18, and a receiving control unit 19.

  The captured video is compressed by a video encoder or the like and input to the transmission control unit 11. The transmission control unit 11 performs modulation processing such as OFDM (Orthogonal Frequency Division Multiplexing), and inputs the IF modulation signal to the transmission high frequency unit 13 via the IF cable 12. IF means Intermediate Frequency. The transmission high-frequency unit 13 converts the IF frequency to an RF (Radio Frequency) frequency, and transmits it as a radio wave via the transmission antenna 14. The transmitted radio wave is received by the receiving antennas 16 a and 16 b through the propagation path 15.

  The receiving antennas 16a and 16b have strong directivities, and must always be directed toward the transmitting antenna 14 as a transmission source during transmission. However, in a mobile transmission system such as an FPU, the characteristics of the propagation path 15 change from moment to moment, and the amplitude and phase of the received signals that reach the receiving antennas 16a and 16b vary greatly. Therefore, a reception diversity system that realizes high reception performance is often used. In reception diversity, a plurality of reception antennas arranged at spatially separated positions are provided for one transmission signal, and characteristics can be improved by combining signals received by the respective antennas.

  FIG. 6 is a diagram illustrating the relationship between the antenna correlation and the diversity effect. In the reception diversity as described above, as shown in FIG. 6, the lower the correlation between the antennas, the greater the improvement due to the diversity, and the improvement effect of 4 to 5 dB is obtained. On the other hand, if the characteristics between the antennas are completely the same (antenna correlation = 1), the improvement is only 3 dB due to the non-correlation of thermal noise, and the improvement is low. This inter-antenna correlation is lowered by increasing the spatial distance between the receiving antennas.

  In the configuration of FIG. 5, signals received by the first receiving antenna 16a and the second receiving antenna 16b and received by the respective receiving antennas are input to the receiving high-frequency unit 17 and have two different IF frequencies. Converted to a signal. In ARIB STD B-57, which is an FPU standard, 130 MHz and 190 MHz are listed as desirable IF frequencies. These IF signals are superimposed and input to the reception control unit 19 via the IF cable 18. The reception control unit 19 combines and demodulates each IF signal by a diversity method such as maximum ratio combining. Thereafter, the video / audio information is obtained by outputting to the video decoder through error correction processing.

  Patent Document 1 below describes the application of diversity reception to the OFDM system.

JP 2008-118710 A

  As described above, in order to keep the correlation between antennas low, it is important to increase the distance between the antennas. However, in reality, when a plurality of antennas are provided in the housing of one reception high-frequency unit 17, there is a problem that the distance between the antennas is narrowed because the antenna installation range is limited.

  It is possible to increase the distance between the antennas by connecting the housing and the antenna with a cable. However, when the frequency is in the order of GHz, there is a lot of loss in the cable. Loss may cancel out. In addition, although it is possible to prevent cable loss by providing an LNA immediately after the receiving antenna, there is a drawback in that the system scale increases, such as an LNA installation mechanism and power supply to the LNA. In this specification, LNA means Low Noise Amplifier.

  By the way, in a big event such as a marathon relay, it is necessary to perform transmission using a plurality of relay vehicles, and an operation using a plurality of FPU systems is performed. FIG. 7 is a configuration diagram of a transmission / reception system using two channels according to the background art, and shows an example using two FPU systems. In FIG. 7, two-channel relaying is performed by transmitting FPU 1-1, transmitting antenna 1-2, transmitting FPU 2-1, transmitting antenna 2-2, receiving FPUs 20, 30, and four receiving antennas 21a, 21b, 31a, 31b. It shows an example of operation using.

  In this way, assuming that the number of FPU systems is N, in the reception diversity system that combines two signals, 2N reception antennas are required. In FPU operation, the receiving antennas 21a, 21b, 31a, 31b are often installed on the top of a mountain, on the roof of a building, or on a steel tower so that the receiving height is as high as possible so as to realize stable reception. This required diversity is very inoperable. In addition, there are many places where it is difficult to transport equipment, and the burden due to the increase in equipment is large. For this reason, compromise is made in that the antenna correlation becomes high, and efforts are made to improve operability by installing two receiving antennas in close proximity to the housings of the receiving FPUs 20 and 30.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a technique capable of improving the characteristics of reception diversity while avoiding an increase in reception facilities.

A typical configuration of the receiving system of the present invention for solving the above-described problems is as follows. That is,
A receiving system including first and second receiving devices,
Each of the first and second receiving apparatuses includes first transmission data, includes a first frequency signal having a carrier frequency corresponding to the first channel, second transmission data, and second A receiving antenna that receives a second frequency signal having a carrier frequency corresponding to the channel, a receiving high-frequency unit, and a receiving control unit;
The reception high-frequency unit of the first and second reception devices is
The first frequency signal and the second frequency signal received by the reception antenna, the first intermediate frequency signal including the first transmission data and having a center frequency corresponding to the first channel; and An intermediate frequency signal generation unit that converts the second transmission data into a second intermediate frequency signal having a center frequency corresponding to the second channel ;
A synthesis unit that synthesizes the first intermediate frequency signal and the second intermediate frequency signal and generates a synthesized signal ;
The reception control unit of the first receiving device is:
A first separation unit for separating the synthesized signal synthesized by the synthesis unit of the first receiving device into the first intermediate frequency signal and the second intermediate frequency signal;
A first diversity combining unit,
The reception control unit of the second receiving device is
A second separation unit for separating the synthesized signal synthesized by the synthesis unit of the second receiver into the first intermediate frequency signal and the second intermediate frequency signal;
A second diversity combining unit,
The first diversity combining unit receives the first intermediate frequency signal separated by the first separation unit and the first intermediate frequency signal separated by the second separation unit, and receives the first intermediate frequency signal. Generating a first diversity combined signal including transmission data;
The second diversity combining unit receives the second intermediate frequency signal separated by the second separation unit and the second intermediate frequency signal separated by the first separation unit, and inputs the second intermediate frequency signal. Generating a second diversity combined signal including transmission data;
The first transmission data is transmission data transmitted from the first mobile station through the first channel, and the second transmission data is a second mobile station different from the first mobile station. The receiving system is transmission data transmitted through the second channel .

  According to the above configuration, it is possible to improve reception diversity characteristics while avoiding an increase in reception facilities.

It is a block diagram of the transmission / reception system which concerns on 1st Example of this invention. It is a figure which shows the mixer and spectrum of BPF which concern on 1st Example of this invention. It is a block diagram of the transmission / reception system which concerns on 2nd Example of this invention. It is a block diagram of the transmission / reception system which concerns on 3rd Example of this invention. It is a block diagram of the transmission / reception system which concerns on background art. It is a figure which shows the relationship between an antenna correlation and a diversity effect. It is a block diagram of the transmission / reception system using 2 channels which concerns on background art.

An embodiment of the present invention will be described.
In the embodiment of the present invention, when constructing a diversity transmission / reception system using a plurality of frequency channels, the reception antenna is shared by a plurality of channels, thereby reducing the system scale and expanding the antenna interval. This reduces antenna correlation and improves diversity performance.

(First embodiment)
First, the 1st Example in embodiment of this invention is demonstrated using FIG. FIG. 1 is a configuration diagram of a transmission / reception system according to the first embodiment, showing an example of performing 2-channel FPU transmission. As described above, the operation using a plurality of channels is performed in the marathon relay etc., but FIG. 1 describes the operation of two channels for easy understanding. An operation example of three channels or more will be described in another embodiment.

  As shown in FIG. 1, the signal (ch1) transmitted from the transmission FPU 1-1 of the first system reaches the reception antenna 101 of the first system and the reception antenna 201 of the second system. Similarly, the signal (ch2) transmitted from the transmission FPU 2-1 of the second system also reaches the reception antenna 101 and the reception antenna 201. Although the detailed configuration will be described later, the first main point of the present embodiment is that the system scale is obtained by receiving the two-channel signals ch1 and ch2 using the two antennas 101 and 201. It is in reducing.

  In addition, since the housing of the reception high-frequency unit 100 to which the reception antenna 101 is connected is different from the housing of the reception high-frequency unit 200 to which the reception antenna 201 is connected, a long cable is used between the reception antenna and the reception high-frequency unit. It is possible to install a wide space between the receiving antennas 101 and 201 without any problem. As a second main point of the present embodiment, this makes it possible to widen the antenna interval, reduce the antenna correlation, and effectively operate the reception diversity.

  As described above, in the embodiment of the present invention, it is possible to achieve both reduction in system scale and improvement in diversity performance. The detailed configuration of the first embodiment will be described below.

  As shown in FIG. 1, this transmission / reception system includes a first system FPU transmission apparatus and a second system FPU transmission apparatus. The FPU transmission apparatus of the first system includes a first transmission FPU1-1 and a first reception FPU as a reception apparatus. The FPU transmission apparatus of the second system includes a second transmission FPU2-1 and a second reception FPU as a reception apparatus. The first transmission FPU1-1 and the second transmission FPU2-1 each include a transmission control unit 11 and a transmission high-frequency unit 13 as in the background art.

  The first transmission FPU 1-1 wirelessly transmits transmission data of a channel (hereinafter also referred to as ch) 1 from the transmission antenna 1-2 using a carrier wave of ch1. Let f1 be the center frequency of the ch1 carrier. The second transmission FPU 2-1 wirelessly transmits the transmission data of ch2 from the transmission antenna 2-2 using the carrier wave of ch2. Let f2 be the center frequency of the carrier wave of ch2. f1 and f2 are different from each other, and the transmission data of ch1 and the transmission data of ch2 are different from each other.

  As illustrated in FIG. 1, the ch1 carrier and the ch2 carrier are received by the reception antenna 101 of the first reception FPU and the reception antenna 201 of the second reception FPU, respectively. In FIG. 1, the ch1 carrier 31 a and the ch2 carrier 32 a are received by the receiving antenna 101, and the ch1 carrier 31 b and the ch2 carrier 32 b are received by the receiving antenna 201.

  As described above, the receiving antenna 101 has a frequency signal including transmission data (ch1) for the receiving device (first receiving FPU) and a frequency signal including transmission data (ch2) for another receiving device (second receiving FPU). Receive. The reception antenna 201 receives a frequency signal including transmission data (ch2) for the reception device (second reception FPU) and a frequency signal including transmission data (ch1) for another reception device (first reception FPU).

  The first reception FPU is a reception device that includes the first reception high-frequency unit 100 and the first reception control unit 110. The first reception high-frequency unit 100 includes a reception antenna 101, an LNA 102, an intermediate frequency signal generation unit 103, and an IF (intermediate frequency signal) synthesis unit 105. The first reception control unit 110 includes an IF (intermediate frequency signal) separation unit 111, a diversity combining unit 112, and an error correction unit 113. An LNA (Low Noise Amplifier) is an amplifier having a small NF (Noise Figure) and may not be provided, but it is desirable to provide it as much as possible. IF is an intermediate frequency or an intermediate frequency signal as described above.

  The intermediate frequency signal generation unit 103 includes a mixer 103a, a mixer 103b, a BPF 104a, and a BPF 104b. The mixer is a frequency converter that converts a high frequency of an input signal into a lower frequency and outputs the converted signal. Specifically, for example, when a signal having a frequency f1 is input, a signal from a local oscillator (not shown) having a predetermined frequency f0 is multiplied and a frequency signal corresponding to the difference between the two signals is output.

  In the first embodiment, a high frequency carrier wave (for example, near 1.2 GHz) received by the receiving antenna 101 and amplified by the LNA 102 is converted to an intermediate frequency having a center frequency of about 130 MHz by the mixer 103a, and the center frequency is converted by the mixer 103b. Is converted to an intermediate frequency of about 190 MHz. The carrier wave includes the ch1 carrier wave (frequency f1) transmitted from the first transmission FPU1-1 and the ch2 carrier wave (frequency f2) transmitted from the second transmission FPU2-1.

  The BPF 104a is a band-pass filter having a pass band corresponding to a bandwidth of approximately one channel centered on about 130 MHz, and a frequency other than the transmission data of ch1 with respect to an intermediate frequency signal near 130 MHz output from the mixer 103a. The signal is suppressed and only the transmission data (ch1-1) of ch1 is passed. The BPF 104b suppresses the frequency signal other than the ch2 transmission data with respect to the intermediate frequency signal near 190 MHz output from the mixer 103b, and passes only the ch2 transmission data (ch2-1).

  Thus, the intermediate frequency signal generation unit 103 receives the carrier signal received by the reception antenna 101 and amplified by the LNA 102, that is, the carrier signal including the transmission data (ch1) for the first reception FPU and the transmission data for the other reception FPUs. The high frequency of the carrier wave signal including (ch2) is converted to an intermediate frequency, and an intermediate frequency signal including transmission data for the first reception FPU and an intermediate frequency signal including transmission data for another reception FPU are generated. In the example of FIG. 1, an intermediate frequency signal including ch1-1 and an intermediate frequency signal including ch2-1 are generated.

  The IF synthesizing unit 105 is a synthesizing unit that synthesizes, that is, adds (superimposes) a plurality of (two in the example of FIG. 1) inputted intermediate frequency signals to generate one intermediate frequency synthesized signal. In the example of FIG. 1, the intermediate frequency signal including ch1-1 and the intermediate frequency signal including ch2-1 are combined to generate a combined signal.

  The IF separation unit 111 is a separation unit that separates the intermediate frequency synthesized signal generated by the IF synthesis unit 105 into a plurality of intermediate frequency signals before being synthesized by the IF synthesis unit 105. In the example of FIG. 1, the intermediate frequency synthesized signal generated by the IF synthesizing unit 105 is discriminated by frequency and separated into an intermediate frequency signal including ch1-1 and an intermediate frequency signal including ch2-1. As described above, the intermediate frequency signal including ch1-1 is approximately 130 MHz, and the intermediate frequency signal including ch2-1 is approximately 190 MHz.

  The diversity combining unit 112 is an intermediate frequency signal separated by the IF separation unit 111 and includes an intermediate frequency signal (about 130 MHz) including transmission data of the channel (ch1-1 in the example of FIG. 1) and other receptions. The intermediate frequency signal separated by the IF separation unit 211 of the device (second receiving FPU in the example of FIG. 1) and including the transmission data of the channel (ch1-2 in the example of FIG. 1) (about 190 MHz) is input and diversity combining is performed to demodulate the signal.

  As an example, diversity combining section 112 combines (maximum ratio combining diversity) so as to maximize the SNR (signal-to-noise power ratio), as is well known.

  Thus, diversity combining section 112 separates the intermediate frequency signal including transmission data (ch1) for the receiving apparatus separated by the separating section of the receiving apparatus (first receiving FPU) and the other receiving apparatuses (second receiving FPU). An intermediate frequency signal separated by the separation unit and including transmission data (ch1) for the receiving device is input, and a diversity combined signal including transmission data (ch1) for the receiving device is generated.

  The error correction unit 113 corrects a transmission error with respect to the signal subjected to diversity combining by the diversity combining unit 112 and outputs a ch1 video signal.

  The second reception FPU is a reception device that includes the second reception high-frequency unit 200 and the second reception control unit 210. The second reception high-frequency unit 200 includes a reception antenna 201, an LNA 202, an intermediate frequency signal generation unit 203, and an IF synthesis unit 205. The second reception control unit 210 includes an IF separation unit 211, a diversity combining unit 212, and an error correction unit 213. The intermediate frequency signal generation unit 203 includes a mixer 203a, a mixer 203b, a BPF 204a, and a BPF 204b.

  In the first embodiment, a high frequency (for example, near 1.2 GHz) carrier wave received by the receiving antenna 201 and amplified by the LNA 202 is converted into an intermediate frequency having a center frequency of about 130 MHz by the mixer 203a, and is around 190 MHz by the mixer 203b. Is converted to an intermediate frequency. This carrier wave includes a carrier wave (frequency f1) transmitted from the first transmission FPU1-1 and a carrier wave (frequency f2) transmitted from the second transmission FPU2-1.

  The BPF 204a suppresses the frequency signal other than the ch2 transmission data with respect to the intermediate frequency signal near 130 MHz output from the mixer 203a, and allows only the ch2 transmission data (ch2-2) to pass. The BPF 204b suppresses the frequency signal other than the transmission data of ch1 with respect to the intermediate frequency signal near 190 MHz output from the mixer 203b, and passes only the transmission data (ch1-2) of ch1.

  Thus, the intermediate frequency signal generator 203 receives the carrier signal received by the receiving antenna 201 and amplified by the LNA 202, that is, the carrier signal including the transmission data (ch2) for the second reception FPU, and the transmission data for the other reception FPUs. The high frequency of the carrier wave signal including (ch1) is converted into an intermediate frequency, and the intermediate frequency signal including the second reception FPU (ch2-2 in the example of FIG. 1) and the transmission data (FIG. 1) In the example, an intermediate frequency signal including ch1-2) is generated.

  The IF synthesis unit 205 is a synthesis unit that synthesizes a plurality of (two in the example of FIG. 1) input intermediate frequency signals to generate one intermediate frequency synthesis signal. In the example of FIG. 1, the intermediate frequency signal including ch2-2 and the intermediate frequency signal including ch1-2 are combined to generate a combined signal.

  The IF separation unit 211 is a separation unit that separates the intermediate frequency synthesized signal generated by the IF synthesis unit 205 into a plurality of intermediate frequency signals before being synthesized by the IF synthesis unit 205. In the example of FIG. 1, the intermediate frequency synthesized signal generated by the IF synthesizing unit 205 is discriminated by frequency and separated into an intermediate frequency signal including ch2-2 and an intermediate frequency signal including ch1-2. As described above, the intermediate frequency signal including ch2-2 is approximately 130 MHz, and the intermediate frequency signal including ch1-2 is approximately 190 MHz.

  The diversity combining unit 212 is an intermediate frequency signal separated by the IF separation unit 211 and includes an intermediate frequency signal (about 130 MHz) including transmission data (ch2-2 in the example of FIG. 1) of the channel and other receptions. The intermediate frequency signal separated by the IF separation unit 111 of the device (first reception FPU in the example of FIG. 1) and including the transmission data of the channel (ch2-1 in the example of FIG. 1) (about 190 MHz) is input and diversity combining is performed to demodulate the signal. As an example, the diversity combining unit 212 performs maximum ratio combining diversity in the same manner as the diversity combining unit 112.

  Thus, diversity combining section 212 separates the intermediate frequency signal including the transmission data (ch2) for the receiving apparatus separated by the separating section of the receiving apparatus (second receiving FPU) and the other receiving apparatuses (first receiving FPU). An intermediate frequency signal separated by the separation unit and including transmission data (ch2) for the receiving device is input, and a diversity combined signal including transmission data (ch2) for the receiving device is generated.

  The error correction unit 213 corrects a transmission error with respect to the signal subjected to diversity combining by the diversity combining unit 212 and outputs a ch2 video signal.

  Next, based on the received signals received by the receiving antennas 101 and 201, the operation until the ch1 transmission data is acquired by the first system receiving apparatus and the ch2 transmission data is acquired by the second system receiving apparatus will be described. The transmission data of ch1 and the transmission data of ch2 are, for example, video signals.

  The receiving antennas 101 and 201 are antennas having directivity, and should be directed to the transmitting antenna 1-2 and the transmitting antenna 2-2, respectively, but when a plurality of relay vehicles approaching each other are in the distance, A plurality of relay vehicles may be captured by one reception beam. In this embodiment, when a relay car runs on a straight road, a reception site is installed on the extension line so that transmission data from a plurality of transmission FPUs can be simultaneously received by one antenna as much as possible. It shall be.

  A received signal received by the receiving antenna 101 is input to the LNA 102 and amplified. A received signal received by the receiving antenna 201 is input to the LNA 202 and amplified. At this time, it is desirable that the difference between the frequencies of the respective channels (ch1 and ch2) is relatively narrow with respect to the carrier frequency (the ratio band is small). This is because the respective channels need to be accommodated in the effective bandwidths of the receiving antennas 101 and 201 and the LNAs 102 and 202. Under these conditions, the LNAs 102 and 202 can simultaneously amplify the reached two-channel signals. Note that this does not prevent the receiving antennas 101 and 201 and the receiving high-frequency units 100 and 200 from being configured to share 1.2 GHz / 2.3 GHz.

  The signal amplified by the LNA 102 is branched and input to the mixers 103a and 103b. With these mixers, the RF frequency of the carrier wave is converted to an IF frequency. At this time, as described above, the mixers 103a and 103b perform conversion to different IF frequencies. Specifically, the RF frequency is converted to 130 MHz in the mixer 103a and 190 MHz in the mixer 103b as recommended in the ARIB standard of the FPU described above.

  The IF signal converted to the IF frequency (130 MHz) by the mixer 103a suppresses the signal outside the ch1 band by the BPF 104a and extracts only the ch1 signal (ch1-1) which is the main signal. The IF signal converted to the IF frequency (190 MHz) by the mixer 103b suppresses the signal outside the ch2 band by the BPF 104b, and extracts only the ch2 signal (ch2-1) as the main signal.

  Similarly, the signal amplified by the LNA 202 is branched and input to the mixers 203a and 203b. With these mixers, the RF frequency of the carrier wave is converted to an IF frequency. Specifically, the RF frequency is converted to 130 MHz in the mixer 203a and 190 MHz in the mixer 203b.

  The IF signal converted to the IF frequency (130 MHz) by the mixer 203a suppresses the signal outside the ch2 band by the BPF 204a and extracts only the ch2 signal (ch2-2) which is the main signal. The IF signal converted to the IF frequency (190 MHz) by the mixer 203b suppresses the signal outside the ch1 band by the BPF 204b and extracts only the ch1 signal (ch1-2) which is the main signal.

FIG. 2 is a diagram illustrating channel selection by the mixer and the BPF according to the first embodiment of the present invention.
As shown in FIG. 2, the received signal received by the first receiving antenna 101 includes the ch1 and ch2 frequencies, but only the ch1 signal (ch1-1) is extracted by the mixer 103a and the BPF 104a. Only the ch2 signal (ch2-1) is extracted by the mixer 103b and the BPF 104b.

  Similarly, the received signal received by the second receiving antenna 201 includes the ch1 and ch2 frequencies, but only the ch1 signal (ch1-2) is extracted by the mixer 203b and the BPF 204b. Only the ch2 signal (ch2-2) is extracted by the BPF 204a.

  Thereafter, the two IF signals (ch1-1 and ch2-1) in the first system are combined by the IF combiner 105 and transmitted to the IF separator 111 via the IF cable 106. The two IF signals (ch1-2 and ch2-2) of the second system are combined by the IF combining unit 205 and transmitted to the IF separation unit 211 via the IF cable 206. By using the configuration of the IF combining unit, it is possible to transmit two IF signals of each system using one IF cable. For example, a coaxial cable is used as the IF cable.

  In this example, the combined signal is transmitted from the IF combining unit (105, 205) to the IF separating unit (111, 211) using an IF cable, but the combined signal is transmitted wirelessly without using a cable. It is also possible to transmit from the IF synthesis unit to the IF separation unit. Moreover, it is not restricted to a coaxial cable, You may transmit with an optical cable using analog modulation.

  In the IF separation unit 111 of the first system, the IF signal synthesized by the IF synthesis unit 105 is separated again into two IF signals, that is, the IF signals before being synthesized by the IF synthesis unit 105 (ch1-1 and ch2). -1). Similarly, in the second system IF separation unit 211, the IF signal synthesized by the IF synthesis unit 205 is separated again into two IF signals, that is, the IF signal (ch1- 2 and ch2-2).

  One IF signal (ch1-1) separated by the IF separation unit 111 is input to the diversity combining unit 112 of the first system. The other IF signal (ch2-1) is input to diversity combining section 212 in the second system. Similarly, one IF signal (ch2-2) separated by the IF separation unit 211 is input to the second diversity combining unit 212, and the other IF signal (ch1-2) is the first diversity. Input to the combining unit 112.

  In this way, by passing one IF signal crossing between the two systems and passing the signals, the diversity combining unit 112 of the first system aggregates the signals of ch1 received by the receiving antennas 101 and 201. The diversity combining unit 212 in the eye collects the ch2 signals received by the receiving antennas 101 and 201.

  At this time, the IF signal (ch2-1) is transferred from the IF separating unit 111 to the diversity combining unit 212, and the IF signal (ch1-2) is transferred from the IF separating unit 211 to the diversity combining unit 112, for example, using a coaxial cable. However, the present invention is not limited to the coaxial cable, and an optical cable or the like may be used.

  The distance between the first reception high-frequency unit 100 where the reception antenna 101 is installed and the second reception high-frequency unit 200 where the reception antenna 201 is installed is set large (for example, several meters or more) in order to enhance the diversity effect. The distance between the first reception control unit 110 in which the diversity combining unit 112 is accommodated and the second reception control unit 210 in which the diversity combining unit 212 is accommodated may be close to each other.

  In other words, the IF signal is transmitted to the other receiving device (IF separating unit 211) than the length of the first cable (106, 206) for transmitting the combined signal from the IF combining unit of the receiving device to the IF separating unit of the receiving device. The length of the second cable transmitted from the receiver to the receiver (diversity combining unit 112) can be shortened. Therefore, the IF signal can be easily transmitted from another receiving apparatus to the receiving apparatus.

  Diversity combining sections 112 and 212 respectively combine two aggregated IF signals using a diversity combining method such as maximum ratio combining that maximizes the combined SNR. Transmission errors of the diversity combined signals are reduced by the error correction units 113 and 213, respectively, and the ch1 video signal is output from the error correction unit 113 and the ch2 video signal is output from the error correction unit 213.

  In the first embodiment, the diversity combining sections 112 and 212 are configured such that the intermediate frequencies of the two input signals are different from each other. However, it is also possible to configure so that signals having the same intermediate frequency are combined. is there. In this case, in the second reception high-frequency unit 200, the BPF 204a passes only the transmission data (ch1-2) of ch1 to the intermediate frequency signal near 130 MHz output from the mixer 203a, and the BPF 204b Only the ch2 transmission data (ch2-2) is allowed to pass through the output intermediate frequency signal near 190 MHz.

  Alternatively, when the arrangement of ch1 and ch2 at a high frequency is fixed, the mixer 103b and the mixer 203b are omitted, and the first reception high-frequency unit 100 outputs the BPF 104a to the intermediate frequency signal around 130 MHz output from the mixer 103a. Passes only the transmission data (ch1-1) of ch1, and the BPF 104b allows only the transmission data (ch2-1) of ch2 to pass. In the second reception high-frequency unit 200, the vicinity of 130 MHz output from the mixer 203a is passed. For the intermediate frequency signal, the BPF 204a may pass only the ch1 transmission data (ch1-2), and the BPF 204b may pass only the ch2 transmission data (ch2-2).

  In the first embodiment, diversity combining is performed by both the first reception control unit 110 and the second reception control unit 210. However, either the first reception control unit 110 or the second reception control unit 210 is used. It is also possible to configure so that diversity combining is performed only on one side. For example, diversity combining is performed only by the first reception control unit 110, and the diversity reception unit 210 is not provided in the second reception control unit 210, and the output (ch2-2) of the IF separation unit 211 is input to the error correction unit 113. , Ch2 video signal. Even in this case, the diversity effect is produced in the video signal of ch1. This method can be used, for example, when the radio wave from the transmission FPU 2-1 is continuously good.

According to the first embodiment, at least the following effects can be obtained.
(A1) In a reception system including a plurality of reception devices, each of the plurality of reception devices receives a first frequency signal including first transmission data for the reception device and second transmission data for other reception devices. A receiving antenna that receives the second frequency signal, a first intermediate frequency signal that includes the first transmission data based on the first frequency signal and the second frequency signal, and a second that includes the second transmission data. An intermediate frequency signal generating unit that generates two intermediate frequency signals, a combining unit that combines the first intermediate frequency signal and the second intermediate frequency signal to generate a combined signal, and the combined signal as the first intermediate frequency signal A separation unit that separates into a second intermediate frequency signal, a first intermediate frequency signal separated by a separation unit of the reception device, and a third transmission data that is separated by a separation unit of another reception device and includes first transmission data Intermediate frequency signal And a diversity combining unit that generates a diversity combined signal including the first transmission data, and thereby reducing the number of antennas (that is, system equipment) and widening the antenna interval. Antenna correlation can be reduced and diversity performance can be improved.
(A2) a first cable that transmits the combined signal from the combining unit of the receiving device to the separating unit of the receiving device, and a second cable that transmits the third intermediate frequency signal from another receiving device to the receiving device. Since the second cable is configured to be shorter than the first cable, the interval between the reception antennas of different systems can be increased, and the interval between the diversity combining units of different systems can be reduced. be able to.
(A3) Since the frequency of the input signal of the diversity combining unit is configured to vary greatly, it is easy to perform diversity combining.

(Second embodiment)
Next, a second example of the embodiment of the present invention will be described with reference to FIG. FIG. 3 is a block diagram of a transmission / reception system according to the second embodiment, showing an example of performing 3-channel FPU transmission. 3, the same components as those in FIG. 1 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the second embodiment, the configuration of three channels will be described. However, it is possible to realize four or more channels by the same extension.

  As shown in FIG. 3, in the second embodiment, a total of three channels of transmission signals (ch1, ch2, ch3) are transmitted from the three transmission FPUs 1-1, 2-1 and 3-1. Similar to the first transmission FPU1-1 and the second transmission FPU2-1, the third transmission FPU3-1 includes a transmission control unit 11 and a transmission high-frequency unit 13, respectively.

  In the first embodiment, the two-channel received signal is passed between the housings of the two systems of reception control units. However, in the second embodiment, the three-channel received signal is transferred to the three systems. Are transferred in a ring shape between the housings of the reception control unit.

  Specifically, the first system receiving antenna 301 receives at least ch1 and ch2 signals, the second system receiving antenna 401 receives at least ch2 and ch3 signals, and the third system receiving antenna 501 at least. The ch3 and ch1 signals are received. Of course, each antenna may receive all the ch1, ch1, and ch3 signals simultaneously. Then, the ch2 signal received by the first system is transferred to the second system, the ch3 signal received by the second system is transferred to the third system, and the ch1 signal received by the third system is transferred to the first system. .

  As illustrated in FIG. 3, the transmission / reception system includes a first system FPU transmission device, a second system FPU transmission device, and a third system FPU transmission device. The FPU transmission apparatus of the first system includes a first transmission FPU1-1 and a first reception FPU. The FPU transmission apparatus of the second system includes a second transmission FPU2-1 and a second reception FPU. The third-system FPU transmission device includes a third transmission FPU 3-1 and a third reception FPU.

  As described in the first embodiment, the first transmission FPU 1-1 wirelessly transmits the transmission data of ch1 from the transmission antenna 1-2 using the carrier wave (f1) of ch1, and the second transmission FPU2-1 , Ch2 transmission data is wirelessly transmitted from the transmission antenna 2-2 using the ch2 carrier wave (f2). The third transmission FPU 3-1 wirelessly transmits the transmission data of ch3 from the transmission antenna 3-2 using the carrier wave of ch3. Let f3 be the center frequency of the carrier wave of ch3. f3 is different from f1 and f2, and the transmission data of ch3 is different from the transmission data of ch1 and the transmission data of ch2.

  As shown in FIG. 3, the ch1 carrier 31a and the ch2 carrier 32a are received by the reception antenna 301 of the first reception FPU, and the ch2 carrier 32b and the ch3 carrier 33b are received by the reception antenna 401 of the second reception FPU. The ch3 carrier 33c and the ch1 carrier 31c are received by the reception antenna 501 of the third reception FPU.

  The first reception FPU includes a first reception high-frequency unit 300 and a first reception control unit 310. The first reception high-frequency unit 300 includes a reception antenna 301, an LNA 302, an intermediate frequency signal generation unit 303, and an IF synthesis unit 305. The intermediate frequency signal generation unit 303 includes a mixer 303a, a mixer 303b, a BPF 304a, and a BPF 304b. The configuration of the first reception high-frequency unit 300 is the same as the configuration of the first reception high-frequency unit 100 of the first embodiment. The LNA 302 has the same function as the LNA 102 of the first embodiment.

  The first reception control unit 310 includes an IF separation unit 311, a diversity combining unit 312, and an error correction unit 313. The configuration of the first reception control unit 310 is also substantially the same as the configuration of the first reception control unit 110 of the first embodiment, but the input of the diversity combining unit 312 is not (ch1-2) from the second system, Only the point (ch1-3) from the third system is different from the first embodiment.

  The second reception FPU includes a second reception high-frequency unit 400 and a second reception control unit 410. The second reception high-frequency unit 400 includes a reception antenna 401, an LNA 402, an intermediate frequency signal generation unit 403, and an IF synthesis unit 405. The intermediate frequency signal generation unit 403 includes a mixer 403a, a mixer 403b, a BPF 404a, and a BPF 404b. The LNA 402 has the same function as the LNA 102 of the first embodiment.

  The configuration of the second reception high-frequency unit 400 is substantially the same as the configuration of the first reception high-frequency unit 300, but the reception antenna 401 receives the ch2 carrier 32b (frequency f2) and the ch3 carrier 33b (frequency f3). Then, one mixer (mixer 403a) converts the frequency to an intermediate frequency signal around 130 MHz, and one BPF (BPF 404a) passes only the transmission data (ch2-2) of ch2, and the other mixer (mixer 403b). The difference is that the frequency is converted into an intermediate frequency signal in the vicinity of 190 MHz, and only the transmission data (ch3-2) of ch3 is passed through the other BPF (BPF 404b).

  The second reception control unit 410 includes an IF separation unit 411, a diversity combining unit 412, and an error correction unit 413. The configuration of the second reception control unit 410 is substantially the same as the configuration of the first reception control unit 310, but one of the outputs (ch2-2) of the IF separation unit 411 is supplied to the diversity combining unit 412 and the IF separation is performed. The other point (ch3-2) of the output of the unit 411 is different from the first reception control unit 310 in that it is supplied to the diversity combining unit 512 of the third system.

  The third reception FPU includes a third reception high-frequency unit 500 and a third reception control unit 510. The third reception high-frequency unit 500 includes a reception antenna 501, an LNA 502, an intermediate frequency signal generation unit 503, and an IF synthesis unit 505. The intermediate frequency signal generation unit 503 includes a mixer 503a, a mixer 503b, a BPF 504a, and a BPF 504b. The LNA 502 has the same function as the LNA 102 of the first embodiment.

  The configuration of the third reception high-frequency unit 500 is substantially the same as the configuration of the first reception high-frequency unit 300. However, the reception antenna 501 receives the ch3 carrier 33c (frequency f3) and the ch1 carrier 31c (frequency f1). Then, one mixer (mixer 503a) converts the frequency to an intermediate frequency signal around 130 MHz, and one BPF (BPF 504a) passes only the transmission data (ch3-3) of ch3 and the other mixer (mixer 503b). Thus, the frequency is converted into an intermediate frequency signal in the vicinity of 190 MHz, and the other BPF (BPF 504b) passes only the transmission data (ch1-3) of ch1.

  The third reception control unit 510 includes an IF separation unit 511, a diversity combining unit 512, and an error correction unit 513. The configuration of the third reception control unit 510 is substantially the same as the configuration of the first reception control unit 310, but one of the outputs (ch3-3) of the IF separation unit 511 is supplied to the diversity combining unit 512, and IF separation is performed. The other (ch1-3) of the output of the unit 511 is different from the first reception control unit 310 in that it is supplied to the diversity combining unit 312 of the first system.

  Next, based on the received signals received by the receiving antennas 301, 401, 501, the first system receiving device transmits the ch1 transmission data, the second system receiving device receives the ch2 transmission data, and the third system receiving device uses the ch3 transmission data. The operation until the transmission data is acquired will be described.

  A received signal received by the receiving antenna 301 is input to the LNA 302 and amplified. A received signal received by the receiving antenna 401 is input to the LNA 402 and amplified. A received signal received by the receiving antenna 501 is input to the LNA 502 and amplified.

  The signal amplified by the LNA 302 is input to the mixers 303a and 303b, and the RF frequency of the carrier wave is converted to an IF frequency. Specifically, the RF frequency is converted to 130 MHz in the mixer 303a and 190 MHz in the mixer 303b.

  Only the ch1 signal (ch1-1) is extracted by the BPF 304a from the IF signal converted to the IF frequency (130 MHz) by the mixer 303a. Only the ch2 signal (ch2-1) is extracted by the BPF 304b from the IF signal converted to the IF frequency (190 MHz) by the mixer 303b.

  Similarly, the signal amplified by the LNA 402 is input to the mixers 403a and 403b, and the RF frequency is converted to 130 MHz by the mixer 403a and 190 MHz by the mixer 403b. Then, only the ch2 signal (ch2-2) is extracted by the BPF 404a from the IF signal converted to the IF frequency (130 MHz) by the mixer 403a. Only the ch3 signal (ch3-2) is extracted by the BPF 404b from the IF signal converted to the IF frequency (190 MHz) by the mixer 403b.

  Similarly, the signals amplified by the LNA 502 are input to the mixers 503a and 503b, and the RF frequency is converted to 130 MHz by the mixer 503a and 190 MHz by the mixer 503b. Then, only the ch3 signal (ch3-3) is extracted by the BPF 504a from the IF signal converted to the IF frequency (130 MHz) by the mixer 503a. Only the ch1 signal (ch1-3) is extracted by the BPF 504b from the IF signal converted to the IF frequency (190 MHz) by the mixer 503b.

  Thereafter, the two IF signals (ch1-1 and ch2-1) in the first system are combined by the IF combiner 305 and sent to the IF separator 311 via the IF cable 306. The two IF signals (ch2-2 and ch3-2) in the second system are combined by the IF combining unit 405 and sent to the IF separation unit 411 through the IF cable 406. Two IF signals (ch3-3 and ch1-3) of the third system are combined by the IF combining unit 505 and sent to the IF separation unit 511 by the IF cable 506.

  In the first system IF separation unit 311, the IF signal synthesized by the IF synthesis unit 305 is separated into IF signals (ch 1-1 and ch 2-1) before being synthesized by the IF synthesis unit 305. Similarly, in the second system IF separation unit 411, the IF signal synthesized by the IF synthesis unit 405 is separated into IF signals (ch2-2 and ch3-2) before being synthesized by the IF synthesis unit 405. . In the third system IF separation unit 511, the IF signal synthesized by the IF synthesis unit 505 is separated into IF signals (ch3-3 and ch1-3) before being synthesized by the IF synthesis unit 505.

  The first IF signal (ch1-1) separated by the IF separation unit 311 is input to the first diversity combining unit 312. The second IF signal (ch2-1) separated by the IF separation unit 311 is input to the diversity combining unit 412 of the second system.

  Similarly, the first IF signal (ch2-2) separated by the IF separation unit 411 is input to the diversity combining unit 412 of the second system, and the second IF signal (ch3-2) is supplied to the three systems. The data is input to the eye diversity combining unit 512.

  Similarly, the first IF signal (ch3-3) separated by the IF separation unit 511 is input to the diversity combining unit 512 of the third system, and the second IF signal (ch1-3) is 1 This is input to the diversity combining unit 312 of the system.

  At this time, the IF signal (ch2-1) is transferred from the IF separation unit 311 to the diversity combining unit 412, the IF signal (ch3-2) is transferred from the IF separation unit 411 to the diversity combining unit 512, and the IF separation unit 511 The IF signal (ch1-3) is transferred to the diversity combining unit 312 using a coaxial cable.

  Diversity combining sections 312, 412, and 512 respectively combine two aggregated IF signals using a diversity combining method such as maximum ratio combining that maximizes the combined SNR. The diversity combined signal is reduced in transmission errors by the error correction units 313, 413, and 513. The error correction unit 313 receives the ch1 video signal, the error correction unit 413 receives the ch2 video signal, and the error correction unit 513 receives the transmission error. The video signal of ch3 is output.

  Thus, since the first reception FPU receives diversity of the ch1 signal, the ch1 signal received by its own reception antenna 301 and the ch1 signal received by the reception antenna 501 and passed through the third reception FPU are aggregated. The video signal of ch1 is acquired as the output of the first reception FPU.

  Similarly, in the second reception FPU, since the ch2 signal is diversity-received, the ch2 signal received by its own reception antenna 401 and the ch2 signal received by the reception antenna 301 and passed through the first reception FPU are aggregated. Then, the ch2 video signal is acquired as the output of the second reception FPU.

  Similarly, in the third reception FPU, since the ch3 signal is diversity-received, the ch3 signal received by its own reception antenna 501 and the ch3 signal received by the reception antenna 401 and passed through the second reception FPU are aggregated. Then, the ch3 video signal is acquired as the output of the third reception FPU.

  In this manner, by passing the IF signal in a ring shape between the housings of the three systems of reception control units, it is possible to realize the reception diversity processing of three channels with the three reception antennas.

  In the second embodiment, as in the first embodiment, the diversity combining units 312, 412 and 512 are configured such that the intermediate frequencies of the respective input signals are different. As described in the first embodiment, however. It is also possible to configure each intermediate frequency to be substantially the same.

  Further, in the second embodiment, the first reception control unit 310, the second reception control unit 410, and the third reception control unit 510 are configured to perform diversity combining. One or two of the reception control unit 410 and the third reception control unit 510 may be configured to perform diversity combining. For example, diversity combining is performed only by the first reception control unit 310 and the second reception control unit 410, and only the output (ch3-3) of the IF separation unit 511 is input to the error correction unit 513 in the third reception control unit 510. , Ch3 video signal. Even in this case, the diversity effect is produced in the video signals of ch1 and ch2.

According to the second embodiment, in addition to the effects of the first embodiment, there are at least the following effects.
(B1) Since the number of diversity combinations is smaller than the number of channels and the number of receiving antennas, the equipment of the receiving apparatus can be reduced.

(Third embodiment)
Next, a third example of the embodiment of the present invention will be described with reference to FIG. FIG. 4 is a configuration diagram of a transmission / reception system according to the third embodiment. The third embodiment is a generalized configuration of the first embodiment. In a transmission / reception system that performs transmission of X channels (X is an integer) that are close in frequency, N (N is an integer) receive antennas are used. Used to perform M (M is an integer and M ≦ N) synthesis diversity. The diversity combining number M needs to be equal to or less than the number N of receiving antennas, and the relationship of M ≦ N is essential.

  FIG. 4 is an example where X = M = N = 3. This is a system that receives diversity transmission signals of X = 3 channels, and includes N = 3 reception antennas. Each reception high-frequency unit (600, 700, 800) includes a mixer with a diversity combination number M = 3 (for example, in the reception high-frequency unit 600, mixers 603a, 603b, and 603c), and generates three IF signals. In each reception control unit (610, 710, 810), the IF signal is again separated into three and passed between the reception control units, so that each diversity combining unit (612, 712, 812) has M = By combining the three IF signals and diversity combining such as maximum ratio combining, it is possible to realize a reception performance higher than the number of combining M = 2 described in the first embodiment.

  Hereinafter, the configuration of the third embodiment will be described in detail. 4, the same components as those in FIG. 3 of the second embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 4, the transmission / reception system includes a first system FPU transmission device, a second system FPU transmission device, and a third system FPU transmission device. The FPU transmission apparatus of the first system includes a first transmission FPU1-1 and a first reception FPU. The FPU transmission apparatus of the second system includes a second transmission FPU2-1 and a second reception FPU. The third-system FPU transmission device includes a third transmission FPU 3-1 and a third reception FPU.

  As described in the second embodiment, the first transmission FPU 1-1 wirelessly transmits the transmission data of ch1 from the transmission antenna 1-2 using the carrier wave (f1) of ch1, and the second transmission FPU2-1 , The transmission data of ch2 is wirelessly transmitted from the transmission antenna 2-2 using the carrier wave (f2) of ch2, and the third transmission FPU 3-1 uses the carrier wave (f3) of ch3, Radio transmission is performed from the transmission antenna 3-2.

  As shown in FIG. 4, the ch1 carrier, the ch2 carrier, and the ch3 carrier are received by the reception antenna 601 of the first reception FPU, the reception antenna 701 of the second reception FPU, and the reception antenna 801 of the third reception FPU. Received respectively. In FIG. 4, the ch1 carrier 31a, the ch2 carrier 32a, and the ch3 carrier 33a are received by the receiving antenna 601, and the ch1 carrier 31b, the ch2 carrier 32b, and the ch3 carrier 33b are received by the receiving antenna 701. A state where the ch1 carrier 31c, the ch2 carrier 32c, and the ch3 carrier 33c are received by the reception antenna 801 is shown.

  The first reception FPU includes a first reception high-frequency unit 600 and a first reception control unit 610. The first reception high-frequency unit 600 includes a reception antenna 601, an LNA 602, an intermediate frequency signal generation unit 603, and an IF synthesis unit 605. The first reception control unit 610 includes an IF separation unit 611, a diversity combining unit 612, and an error correction unit 613. The LNA 602 has the same function as the LNA 102 of the first embodiment.

  The intermediate frequency signal generation unit 603 includes a mixer 603a, a mixer 603b, a mixer 603c, a BPF 604a, a BPF 604b, and a BPF 604c.

  The mixer 603a converts the high frequency amplified by the LNA 602 into an intermediate frequency near 130 MHz, and the BPF 604a suppresses frequency signals other than the ch1 transmission data with respect to the intermediate frequency signal near 130 MHz, and the ch1 transmission data. Pass only (ch1-1).

  The mixer 603b converts the high frequency amplified by the LNA 602 into an intermediate frequency near 190 MHz, and the BPF 604b suppresses frequency signals other than the transmission data of ch2 with respect to the intermediate frequency signal near 190 MHz, and transmits the transmission data of ch2. Pass only (ch2-1).

  The mixer 603c converts the high frequency amplified by the LNA 602 into an intermediate frequency near 250 MHz, and the BPF 604c suppresses the frequency signal other than the ch3 transmission data with respect to the intermediate frequency signal near 250 MHz, and transmits the ch3 transmission data. Pass only (ch3-1).

  The IF synthesis unit 605 synthesizes a plurality of (three in the example of FIG. 4) intermediate frequency signals that are input to generate one intermediate frequency synthesis signal. In the example of FIG. 4, an intermediate frequency signal including ch1-1, an intermediate frequency signal including ch2-1, and an intermediate frequency signal including ch3-1 are synthesized.

  The IF separation unit 611 separates the intermediate frequency synthesized signal generated by the IF synthesis unit 605 into a plurality of intermediate frequency signals before being synthesized by the IF synthesis unit 605. In the example of FIG. 4, the intermediate frequency synthesized signal generated by the IF synthesizing unit 605 is discriminated by frequency, and includes an intermediate frequency signal including ch1-1, an intermediate frequency signal including ch2-1, and ch3-1. Separated into an intermediate frequency signal. As described above, the intermediate frequency signal including ch1-1 is approximately 130 MHz, the intermediate frequency signal including ch2-1 is approximately 190 MHz, and the intermediate frequency signal including ch3-1 is approximately 250 MHz.

  Diversity combining section 612 includes an intermediate frequency signal including transmission data (ch1-1) of the channel (ch1 in the example of FIG. 4) separated by IF separating section 611, and another receiving apparatus (in the example of FIG. Diversity combining by inputting an intermediate frequency signal separated by an IF separator of (2 reception FPU and 3rd reception FPU) and including transmission data (ch1-2, ch1-3) of the channel To demodulate the signal.

  The error correction unit 613 corrects a transmission error with respect to the signal subjected to diversity combining by the diversity combining unit 612 and outputs a ch1 video signal.

  The second reception FPU includes a second reception high frequency unit 700 and a second reception control unit 710. The second reception high-frequency unit 700 includes a reception antenna 701, an LNA 702, an intermediate frequency signal generation unit 703, and an IF synthesis unit 705. The second reception control unit 710 includes an IF separation unit 711, a diversity combining unit 712, and an error correction unit 713. The LNA 702 has the same function as the LNA 102 of the first embodiment.

  The intermediate frequency signal generation unit 703 includes a mixer 703a, a mixer 703b, a mixer 703c, a BPF 704a, a BPF 704b, and a BPF 704c.

  The mixer 703a converts the high frequency amplified by the LNA 702 into an intermediate frequency near 190 MHz, and the BPF 704a suppresses the frequency signal other than the transmission data of ch1 with respect to the intermediate frequency signal near 190 MHz, and the transmission data of ch1 Pass only (ch1-2).

  The mixer 703b converts the high frequency amplified by the LNA 702 into an intermediate frequency near 250 MHz, and the BPF 704b suppresses the frequency signal other than the ch2 transmission data with respect to the intermediate frequency signal near 250 MHz, and the ch2 transmission data Pass only (ch2-2).

  The mixer 703c converts the high frequency amplified by the LNA 702 into an intermediate frequency near 130 MHz, and the BPF 704c suppresses the frequency signal other than the ch3 transmission data with respect to the intermediate frequency signal near 130 MHz, and transmits the ch3 transmission data. Pass only (ch3-2).

  The IF combining unit 705 combines a plurality of input intermediate frequency signals (three in the example of FIG. 4) to generate one intermediate frequency combined signal. In the example of FIG. 4, an intermediate frequency signal including ch1-2, an intermediate frequency signal including ch2-2, and an intermediate frequency signal including ch3-2 are synthesized.

  The IF separation unit 711 separates the intermediate frequency synthesized signal generated by the IF synthesis unit 705 into a plurality of intermediate frequency signals before being synthesized by the IF synthesis unit 705. In the example of FIG. 4, the intermediate frequency synthesized signal generated by the IF synthesizing unit 705 is discriminated by frequency, and includes an intermediate frequency signal including ch1-2, an intermediate frequency signal including ch2-2, and ch3-2. Separated into an intermediate frequency signal. As described above, the intermediate frequency signal including ch1-2 is approximately 190 MHz, the intermediate frequency signal including ch2-2 is approximately 250 MHz, and the intermediate frequency signal including ch3-2 is approximately 130 MHz.

  The diversity combining unit 712 includes an intermediate frequency signal (ch2-2) including transmission data of the channel (ch2 in the example of FIG. 4) separated by the IF separation unit 711, and another receiving device (in the example of FIG. Diversity combining by inputting intermediate frequency signals (ch2-1, ch2-3) including the transmission data of the channel, which are intermediate frequency signals separated by the IF separation unit of the first reception FPU and the third reception FPU) To demodulate the signal.

  The error correction unit 713 corrects a transmission error with respect to the signal subjected to diversity combining by the diversity combining unit 712, and outputs a ch2 video signal.

  The third reception FPU includes a third reception high frequency unit 800 and a third reception control unit 810. The third reception high-frequency unit 800 includes a reception antenna 801, an LNA 802, an intermediate frequency signal generation unit 803, and an IF synthesis unit 805. The third reception control unit 810 includes an IF separation unit 811, a diversity combining unit 812, and an error correction unit 813. The LNA 802 has the same function as the LNA 102 of the first embodiment.

  The intermediate frequency signal generation unit 803 includes a mixer 803a, a mixer 803b, a mixer 803c, a BPF 804a, a BPF 804b, and a BPF 804c.

  The mixer 803a converts the high frequency amplified by the LNA 802 into an intermediate frequency near 250 MHz, and the BPF 804a suppresses the frequency signal other than the ch1 transmission data with respect to the intermediate frequency signal near 250 MHz, and the ch1 transmission data Pass only (ch1-3).

  The mixer 803b converts the high frequency amplified by the LNA 802 into an intermediate frequency near 130 MHz, and the BPF 804b suppresses the frequency signal other than the ch2 transmission data with respect to the intermediate frequency signal near 130 MHz, and the ch2 transmission data Pass only (ch2-3).

  The mixer 803c converts the high frequency amplified by the LNA 802 into an intermediate frequency near 190 MHz, and the BPF 804c suppresses the frequency signal other than the transmission data of ch3 with respect to the intermediate frequency signal near 190 MHz, and the transmission data of ch3 Pass only (ch3-3).

  The IF synthesis unit 805 synthesizes a plurality of input (three in the example of FIG. 4) intermediate frequency signals to generate one intermediate frequency synthesis signal. In the example of FIG. 4, the intermediate frequency signal including ch1-3, the intermediate frequency signal including ch2-3, and the intermediate frequency signal including ch3-3 are synthesized.

  The IF separation unit 811 separates the intermediate frequency synthesized signal generated by the IF synthesis unit 805 into a plurality of intermediate frequency signals before being synthesized by the IF synthesis unit 805. In the example of FIG. 4, the intermediate frequency synthesized signal generated by the IF synthesizing unit 805 is discriminated by frequency, and includes an intermediate frequency signal including ch1-3, an intermediate frequency signal including ch2-3, and ch3-3. Separated into an intermediate frequency signal. As described above, the intermediate frequency signal including ch1-3 is approximately 250 MHz, the intermediate frequency signal including ch2-3 is approximately 130 MHz, and the intermediate frequency signal including ch3-3 is approximately 190 MHz.

  Diversity combining section 812 includes an intermediate frequency signal including transmission data (ch3-3) of the channel (ch3 in the example of FIG. 4) separated by IF separating section 811 and the other receiving apparatus (in the example of FIG. Diversity combining by inputting an intermediate frequency signal separated by the IF separator of (1 reception FPU and 2 reception FPU) and including the transmission data (ch3-1, ch3-2) of the channel To demodulate the signal.

  The error correction unit 813 corrects a transmission error for the signal subjected to diversity combining by the diversity combining unit 812 and outputs a ch3 video signal.

  Next, based on the received signals received by the receiving antennas 601, 701, and 801, ch1 transmission data is received by the first system receiver, ch2 transmission data is received by the second system receiver, and ch3 is received by the third system receiver. The operation until the transmission data is acquired will be described.

  A received signal received by the receiving antenna 601 is input to the LNA 602 and amplified. A received signal received by the receiving antenna 701 is input to the LNA 702 and amplified. A received signal received by the receiving antenna 801 is input to the LNA 802 and amplified.

  The signal amplified by the LNA 602 is input to the mixers 603a, 603b, and 603c, and the RF frequency of the carrier wave is converted to an IF frequency. Specifically, the RF frequency is converted to 130 MHz in the mixer 603a, 190 MHz in the mixer 603b, and 250 MHz in the mixer 603c.

  Only the ch1 signal (ch1-1) is extracted by the BPF 604a from the IF signal converted to the IF frequency (130 MHz) by the mixer 603a. Only the ch2 signal (ch2-1) is extracted by the BPF 604b from the IF signal converted to the IF frequency (190 MHz) by the mixer 603b. Only the ch3 signal (ch3-1) is extracted by the BPF 604c from the IF signal converted to the IF frequency (250 MHz) by the mixer 603c.

  Similarly, the signals amplified by the LNA 702 are input to the mixers 703a, 703b, and 703c, and the RF frequency is converted to 190 MHz by the mixer 703a, 250 MHz by the mixer 703b, and 130 MHz by the mixer 703c. Then, only the ch1 signal (ch1-2) is extracted by the BPF 704a from the IF signal converted to the IF frequency (190 MHz) by the mixer 703a. Only the ch2 signal (ch2-2) is extracted by the BPF 704b from the IF signal converted to the IF frequency (250 MHz) by the mixer 703b. Only the ch3 signal (ch3-2) is extracted by the BPF 704c from the IF signal converted to the IF frequency (130 MHz) by the mixer 703c.

  Similarly, the signal amplified by the LNA 802 is input to the mixers 803a, 803b, and 803c, and the RF frequency is converted to 250 MHz by the mixer 803a, 130 MHz by the mixer 803b, and 190 MHz by the mixer 803c. Then, only the ch1 signal (ch1-3) is extracted by the BPF 804a from the IF signal converted to the IF frequency (250 MHz) by the mixer 803a. Only the ch2 signal (ch2-3) is extracted by the BPF 804b from the IF signal converted to the IF frequency (130 MHz) by the mixer 803b. Only the ch3 signal (ch3-3) is extracted by the BPF 804c from the IF signal converted to the IF frequency (190 MHz) by the mixer 803c.

  Thereafter, the three IF signals (ch1-1, ch2-1, and ch3-1) of the first system are combined by the IF combiner 605 and sent to the IF separator 611 via the IF cable 606. The three IF signals (ch1-2, ch2-2, and ch3-2) in the second system are combined by the IF combining unit 705 and sent to the IF separation unit 711 through the IF cable 706. Three IF signals (ch1-3, ch2-3, and ch3-3) of the third system are combined by the IF combiner 805 and sent to the IF separator 811 via the IF cable 806.

  In the IF separation unit 611 of the first system, the IF signal synthesized by the IF synthesis unit 605 is separated into IF signals (ch1-1, ch2-1, and ch3-1) before being synthesized by the IF synthesis unit 605. The Similarly, in the second system IF separation unit 711, the IF signal synthesized by the IF synthesis unit 705 is the IF signal before being synthesized by the IF synthesis unit 705 (ch1-2, ch2-2, and ch3-2). Separated. In the third-system IF separation unit 811, the IF signal synthesized by the IF synthesis unit 805 is separated into IF signals (ch 1-3, ch 2-3, and ch 3-3) before being synthesized by the IF synthesis unit 805. The

  The first IF signal (ch1-1) separated by the IF separation unit 611 is input to the first diversity combining unit 612. The second IF signal (ch2-1) separated by the IF separation unit 611 is input to the second diversity combining unit 712. The third IF signal (ch3-1) separated by the IF separation unit 611 is input to the diversity combining unit 812 of the third system.

  Similarly, the first IF signal (ch1-2) separated by the IF separation unit 711 is input to the first diversity combining unit 612, and the second IF signal (ch2-2) is two systems. The third IF signal (ch 3-2) input to the third diversity combining unit 712 is input to the third diversity combining unit 812.

  Similarly, the first IF signal (ch1-3) separated by the IF separation unit 811 is input to the first diversity combining unit 612, and the second IF signal (ch2-3) is 2 The third IF signal (ch3-3) is input to the diversity combining unit 712 of the system, and is input to the diversity combining unit 812 of the third system.

  At this time, the IF signal (ch2-1) is transferred from the IF separating unit 611 to the diversity combining unit 712, the IF signal (ch3-1) is transferred to the diversity combining unit 812, and the IF separating unit 711 to the diversity combining unit 612. IF signal (ch1-2) delivery, IF signal (ch3-2) delivery to diversity combining unit 812, IF signal (ch2-3) delivery from IF separating unit 811 to diversity combining unit 712, and diversity combining The IF signal (ch1-3) is transferred to the unit 612 using a coaxial cable.

  Diversity combining sections 612, 712, and 812 respectively combine the aggregated three IF signals using a diversity combining method such as maximum ratio combining that maximizes the combined SNR. The diversity combined signal is reduced in transmission errors by the error correction units 613, 713, and 813. From the error correction unit 613, the ch1 video signal, from the error correction unit 713, the ch2 video signal, and from the error correction unit 813 The video signal of ch3 is output.

  In FIG. 4, an example in which X (number of channels) = M (diversity combining number) = N (number of receiving antennas) = 3 has been described, but it is possible to set X = N = 4 or more. When N = 4 or more, the diversity combining number M may be configured to be smaller than the channel number X. Even in this case, it is possible to realize higher reception performance than the background art. Note that the case of X = N = 3 and M = 2 is as shown in the second embodiment.

  Further, in the third embodiment, as in the first embodiment, the diversity combining sections 612, 712, and 812 are configured such that the frequencies of the respective input signals are greatly different. However, as described in the first embodiment, It is also possible to configure so that the frequencies of the respective input signals are substantially the same.

  In the third embodiment, the first reception control unit 610, the second reception control unit 710, and the third reception control unit 810 are configured to perform diversity combining. However, the first reception control unit 610 and the second reception control unit 810 are configured to perform diversity combining. One or two of the reception control unit 710 and the third reception control unit 810 may be configured to perform diversity combining. For example, only the first reception control unit 610 and the second reception control unit 710 perform diversity combining, and the third reception control unit 810 inputs only the output (ch3-3) of the IF separation unit 811 to the error correction unit 813. , Ch3 video signal. Even in this case, the diversity effect is produced in the video signals of ch1 and ch2.

According to the third embodiment, in addition to the effects of the first embodiment, there are at least the following effects.
(C1) Since the receiving system is configured with the number of channels X = diversity combining number M = the number of receiving antennas N = 3 or more, the diversity performance is improved as compared with the second embodiment in which the number of M is reduced compared to X = N. Can be improved.

  As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to each above-mentioned embodiment, A various change is possible in the range which does not deviate from the summary.

  In the above embodiment, the case of FPU transmission has been described. However, the present invention is not limited to FPU transmission, and can be applied to other than FPU transmission.

Further, the present invention can be understood not only as an apparatus, system, or method for executing the processing according to the present invention, but also as a program for realizing such a method or system, a recording medium for recording the program, or the like. it can.
Further, the present invention may be configured such that the CPU performs control by executing a control program stored in a memory, or may be configured as a hardware circuit.

  1-1 ... 1st transmission FPU, 1-2 ... transmission antenna, 2-1 ... 2nd transmission FPU, 2-2 ... transmission antenna, 3-1 ... transmission FPU, 3-2 ... transmission antenna, 11 ... transmission control , 12 ... IF cable, 13 ... transmission high frequency part, 14 ... transmission antenna, 15 ... propagation path, 16a, 16b ... reception antenna, 17 ... reception high frequency part, 18 ... IF cable, 19 ... reception control part, 20 ... reception FPU, 21a, 21b ... receiving antenna, 30 ... receiving FPU, 31a, 31b ... receiving antenna, 100 ... first receiving high frequency unit, 101 ... receiving antenna, 102 ... LNA, 103 ... intermediate frequency signal generating unit, 103a, 103b ... Mixer, 104a, 104b ... BPF, 105 ... IF synthesis unit (synthesis unit), 106 ... IF cable, 110 ... first reception control unit, 111 ... IF separation unit (separation unit), 1 DESCRIPTION OF SYMBOLS 12 ... Diversity synthetic | combination part, 113 ... Error correction part, 200 ... 2nd receiving high frequency part, 201 ... Reception antenna, 202 ... LNA, 203 ... Intermediate frequency signal generation part, 203a, 203b ... Mixer, 204a, 204b ... BPF, 205 ... IF combining section, 206 ... IF cable, 210 ... second reception control section, 211 ... IF separating section, 212 ... diversity combining section, 213 ... error correcting section.

Claims (3)

A receiving system including first and second receiving devices,
Each of the first and second receiving apparatuses includes first transmission data, includes a first frequency signal having a carrier frequency corresponding to the first channel, second transmission data, and second A receiving antenna that receives a second frequency signal having a carrier frequency corresponding to the channel, a receiving high-frequency unit, and a receiving control unit;
The reception high-frequency unit of the first and second reception devices is
The first frequency signal and the second frequency signal received by the reception antenna, the first intermediate frequency signal including the first transmission data and having a center frequency corresponding to the first channel; and An intermediate frequency signal generation unit that converts the second transmission data into a second intermediate frequency signal having a center frequency corresponding to the second channel ;
A synthesis unit that synthesizes the first intermediate frequency signal and the second intermediate frequency signal and generates a synthesized signal ;
The reception control unit of the first receiving device is:
A first separation unit that separates the synthesized signal synthesized by the synthesis unit of the first receiving device into the first intermediate frequency signal and the second intermediate frequency signal;
A first diversity combining unit,
The reception control unit of the second receiving device is
A second separation unit for separating the synthesized signal synthesized by the synthesis unit of the second receiver into the first intermediate frequency signal and the second intermediate frequency signal;
A second diversity combining unit,
The first diversity combining unit receives the first intermediate frequency signal separated by the first separation unit and the first intermediate frequency signal separated by the second separation unit, and receives the first intermediate frequency signal. Generating a first diversity combined signal including transmission data;
The second diversity combining unit receives the second intermediate frequency signal separated by the second separation unit and the second intermediate frequency signal separated by the first separation unit, and inputs the second intermediate frequency signal. Generating a second diversity combined signal including transmission data;
The first transmission data is transmission data transmitted from the first mobile station through the first channel, and the second transmission data is a second mobile station different from the first mobile station. The receiving system is transmission data transmitted through the second channel . The receiving system according to claim 1,
A first cable for transmitting the combined signal from the combining unit of the first receiving device to the first separating unit;
A second cable for transmitting the second intermediate frequency signal separated by the first separation unit from the first separation unit to the second diversity combining unit;
A third cable for transmitting the combined signal from the combining unit of the second receiving device to the second separating unit;
A fourth cable for transmitting the first intermediate frequency signal separated from the second separation unit by the second separation unit to the first diversity combining unit;
The receiving system, wherein the second cable is shorter than the first cable, and the fourth cable is shorter than the third cable . The receiving system according to claim 1,
The case of the reception high-frequency unit to which the reception antenna of the first reception device is connected is different from the case of the reception high-frequency unit to which the reception antenna of the second reception device is connected. And receiving system.

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