JP2016046548A - Communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To successfully prevent interference between antennas due to the wrap-around of radio waves.SOLUTION: A communication device (10) comprises: antennas (2a, 2b); variable band filter units (4a, 4b) capable of changing an elimination band; transmission/reception circuits (5a, 5b); a transmission/reception frequency setting unit (11) for setting a use frequency band to the transmission/reception circuits (5a, 5b); and an elimination frequency setting unit (12) for controlling the filter units (4a, 4b) to eliminate the use frequency band of the particular transmission/reception circuits (5b, 5a).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a communication device, and more particularly, to a communication device including a plurality of antennas.

  Conventionally, in a communication apparatus having a plurality of antennas, such as a communication apparatus that relays a radio signal between a base station and a slave unit, each antenna has directivity, and the null points are directed toward each other. Isolation between them is ensured. For example, in the technique described in Patent Document 1, a receiving antenna and a transmitting antenna having strong directivity in the base station direction are juxtaposed in a direction orthogonal to the base station direction, thereby reducing the coupling between the antennas. doing.

Japanese Patent Laid-Open No. 8-298485 (published on November 12, 1996)

  However, in the prior art, when the directivity of the antenna is insufficient, a radio wave wraps around from the transmitting antenna to the receiving antenna, which may cause interference between the antennas. In particular, this problem becomes conspicuous when the frequency bands used for transmission and reception are close to each other, such as when transmission and reception are performed by channels set in frequency bands used in the same communication system.

  In the technique described in Patent Document 1, a reception antenna and a transmission antenna are provided with a pand filter that transmits a carrier wave. However, according to the unique knowledge of the present inventors, it is difficult for the bandpass filter to successfully block the above-described interference between antennas due to the wraparound of radio waves. This is because if the transmission band of the band-pass filter is wide, the sneak path of the radio wave in the frequency band used for transmission is insufficient, and if the transmission band of the band-pass filter is narrow, the frequency band used for reception is switched. This is because there is a problem that it becomes difficult to cope with the problem.

  The present invention has been made in view of the above problems, and a main object of the present invention is to provide a technique for successfully preventing interference between antennas due to wraparound of radio waves.

  In order to solve the above-described problem, a communication apparatus according to an aspect of the present invention includes first and second transmission / reception units that process signals transmitted and received by the first and second antennas and the first and second antennas, respectively. The first and second band elimination filter units, which are interposed between the first antenna and the first transmission / reception unit and between the second antenna and the second transmission / reception unit, respectively, and whose removal band is variable, And setting means for setting different used frequency bands in the second transmitting / receiving unit, the first band removing filter unit removing the used frequency band of the second transmitting / receiving unit, and the second band removing filter unit using the first transmitting / receiving unit. Control means for controlling the first and second band filter units is provided so as to remove the frequency band.

  According to one embodiment of the present invention, there is an effect that interference between antennas due to wraparound of radio waves can be successfully prevented.

It is a block diagram which shows the structure of the communication apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the structural example of the variable band filter part which concerns on Embodiment 1 of this invention. In Embodiment 1 of this invention, it is a graph which shows an example of the frequency characteristic of the high frequency signal which one transmission / reception circuit output, and an example of the frequency characteristic when the said high frequency signal is input into the other transmission / reception circuit. . It is a block diagram which shows the structure of the communication apparatus which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the communication apparatus which concerns on Embodiment 3 of this invention.

Embodiment 1
Hereinafter, embodiments of the present invention will be described in detail. However, the configuration described in this embodiment is merely an illustrative example, and is not intended to limit the scope of the present invention only to that unless otherwise specified.

  In the following embodiments, a case where the communication apparatus according to the present invention is realized as a wireless relay apparatus will be described, but the present invention is not limited to this. The present invention can be applied to a communication apparatus generally including two or more sets of radio blocks including an antenna, a variable filter, and a radio circuit. More preferably, each radio block is set within a band used for the same communication system. In addition, the present invention can be applied to general communication apparatuses that perform communication using different channels (frequency bands used). More preferably, each wireless block is stored in the same casing.

<Device configuration and overview>
First, the configuration of the communication apparatus according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a communication device 10 according to the present embodiment. The communication device 10 is a relay station that communicates with a base station and a child device, and is a device that relays wireless communication between the base station and another base station and between the base station and the child device. The communication device 10 includes a control unit 1, a channel A transmission / reception block (radio block) 6, and a channel B transmission / reception block (radio block) 7 in the same housing.

  The channel A transmission / reception block 6 includes an antenna 2a (first antenna), a matching circuit 3a, a variable band filter unit 4a (first band removal filter), and a transmission / reception circuit 5a (first transmission / reception unit). The antenna 2a transmits and receives radio signals to and from the base station or the slave unit. The matching circuit 3a matches the impedance of the antenna 2a with an impedance suitable for the frequency band used by the connected transmission / reception circuit 5a.

  The variable band filter unit 4a is a band elimination filter that is interposed between the matching circuit 3a and the transmission / reception circuit 5a and that removes a signal in the removal band and allows a signal in other frequency bands to be transmitted. is there. A configuration example of the variable band filter unit 4a will be described with reference to FIG. FIG. 2 is a diagram illustrating a configuration example of the variable band filter unit 4a according to the present embodiment.

  As shown in FIG. 2A, the variable band filter unit 4a may be configured by a variable notch filter element. Further, as shown in FIG. 2B, the variable band filter unit 4a may be constituted by a resonance circuit in which a variable capacitor and a coil are connected in parallel. Further, as shown in FIG. 2C, the variable band filter unit 4a includes a plurality of notch filter elements for removing signals in different frequency bands, and is switched to the notch filter element used at that time by a switch. You may comprise as follows.

The transmission / reception circuit 5a is configured as a communication module, for example, and is a circuit that performs processing (A / D conversion, D / A conversion, modulation / demodulation, multiplexing / separation, etc.) of a high-frequency signal transmitted and received by the antenna 2a. The transmission / reception circuit 5a performs transmission processing and reception processing of a high-frequency signal belonging to the use frequency band (channel A) set in the transmission / reception circuit 5a.

  The channel B transmission / reception block 7 includes an antenna 2b (second antenna), a matching circuit 3b, a variable band filter unit 4b (second band removal filter unit), and a transmission / reception circuit 5b (second transmission / reception unit). The function of each component is the same as the function of the corresponding component of the channel A transmission / reception block 6 described above, and a description thereof will be omitted.

<Frequency setting process>
As shown in FIG. 1, the control unit 1 includes a transmission / reception frequency setting unit 11 (setting unit) and a removal frequency setting unit 12 (control unit) as functional blocks. The transmission / reception frequency setting unit 11 determines different frequency bands fA and fB, sets the frequency band fA as a use frequency band (channel A) used by the transmission / reception circuit 5a, and uses the frequency band fB by the transmission / reception circuit 5b. To be used as a frequency band (channel B) to be used. In other words, the transmission / reception frequency setting unit 11 assigns the frequency band fA and frequency band fB within the frequency band fBand used in the communication system used by the communication device 10 to the channel A transmission / reception block 6 and the channel B transmission / reception block 7, respectively. Assign.

  The removal frequency setting unit 12 sets the transmission / reception circuits (transmission / reception circuit 5b for the variable band filter unit 4a and transmission / reception circuit 5a for the variable band filter unit 4b) belonging to different radio blocks for each of the variable band filter units 4a and 4b. Control to remove the used frequency band. In the present embodiment, the removal frequency setting unit 12 sets the frequency band fA set by the transmission / reception frequency setting unit 11 in the transmission / reception circuit 5a as the removal band of the variable band filter unit 4b. The transmission / reception frequency setting unit 11 sets the frequency band fB set in the transmission / reception circuit 5b as the removal frequency band of the variable band filter unit 4a.

  FIG. 3 shows an example of frequency characteristics of the high-frequency signal output from the transmission / reception circuit 5a (transmission unit) (broken line) and an example of frequency characteristics when the high-frequency signal is input to the transmission / reception circuit 5b (reception unit) (solid line). It is a graph which shows and.

  As indicated by the broken line in FIG. 3, the high-frequency signal output from the transmission / reception circuit 5a includes a component of channel B (frequency band fB). Therefore, when the high-frequency signal output from the transmission / reception circuit 5a wraps around the transmission / reception circuit 5b via the antenna 2a and the antenna 2b, the noise floor in the signal processed by the transmission / reception circuit 5b increases, and the signal processed by the transmission / reception circuit 5b increases. C / N deteriorates.

  Here, in the present embodiment, the frequency band fB is removed from the high frequency signal output from the transmission / reception circuit 5a by the variable band filter unit 4a. The high frequency signal received by the antenna 2b is removed from the frequency band fA by the variable band filter unit 4b. Therefore, the reception level of the high-frequency signal derived from the transmission / reception circuit 5a that wraps around the transmission / reception circuit 5b is reduced in the frequency bands fA and fB, as indicated by the solid line in FIG. Thereby, the noise floor in the signal processed by the transmission / reception circuit 5b can be reduced, and the C / N of the signal processed by the transmission / reception circuit 5b can be improved.

As described above, according to the present embodiment, the variable band filter unit 4a of the channel A transmission / reception block 6 reduces the transmission level of the channel B in the transmission signal (the bottom level of the transmission signal) and the channel B of the reception signal. The reception level (strong input level of the high frequency signal that wraps around from the channel B transmission / reception block 7) can be lowered. Further, the variable band filter unit 4b of the channel B transmission / reception block 7 reduces the transmission level of the channel A in the transmission signal (base level of the transmission signal) and also receives the reception level of the channel A in the reception signal (from the channel A transmission / reception block 6). The strong input level of the high-frequency signal that wraps around can be reduced.

  As a result, it is possible to reduce both the strong input level (the used frequency band of the other radio block) and the bottom level (the used frequency band of the own radio block) of the reception signal that wraps around from the other radio block. That is, interference between antennas can be reduced.

  In the related art using a bandpass filter, if the transmission band of the bandpass filter is wide, blocking of the wraparound of radio waves in the frequency band used for transmission is insufficient, and if the transmission band of the bandpass filter is narrow Therefore, there arises a problem that it becomes difficult to cope with switching of the used frequency band for reception. On the other hand, according to the present embodiment, it is possible to ensure isolation between antennas and to cut off a sneak signal flexibly by using a steep band elimination filter whose removal band is variable, and a frequency used for reception. It becomes easy to respond to the change of belt.

  Further, according to the present embodiment, even if the directivity of each antenna is broad, the variable band filter units 4a and 4b compensate for the degradation of the isolation between the antennas due to the broad directivity of each antenna. Since the C / N ratio can be ensured, the directivity of each antenna can be broadened, and the degree of freedom of arrangement of communication devices increases.

  In particular, the intra-station interference of the radio relay station affects the power that can be transmitted, and is thus directly connected to the distance between base stations. For this reason, in the conventional example, interference is reduced by reducing directivity. However, in the case of a small wireless relay station, for example, it is necessary for efficient station arrangement to wait for a three-dimensional degree of freedom of arrangement. According to the present embodiment, since it is possible to reduce interference between antennas without reducing directivity, the degree of freedom of station arrangement can be increased.

  The channel A transmission / reception block 6 may be dedicated for transmission, and the channel B transmission / reception block 7 may be dedicated for reception. In other words, the transmission / reception unit 5a may process at least the transmission signal, and the transmission / reception unit 5b may process at least the reception signal. Even with such a configuration, it is possible to suppress interference between antennas due to wraparound of radio waves from the antenna 2a to the antenna 2b.

[Embodiment 2]
Next, the communication device 10a according to the second embodiment of the present invention will be described. The communication device 10a according to the second embodiment of the present invention further includes a transmission / reception determination unit (processing determination unit) 13 that determines whether each of the transmission / reception circuits 5a and 5b processes a signal. When it is determined that only one of the transmission / reception circuits 5a and 5b is processing a signal, the removal frequency setting unit 12 sets the removal band of the band removal filter unit connected to the one transmission / reception unit, The communication device 10 according to the first embodiment is different from the communication device 10 according to the first embodiment in that it is moved to a frequency band that is a predetermined value or more away from the use frequency band of the one transmission / reception unit.

  Note that a frequency band that is more than a predetermined value away from the use frequency band of one transmission / reception unit means that the center frequency of the frequency band is a channel that is transmitting / receiving with respect to the center frequency of the use frequency band of one transmission / reception unit. This indicates that the bandwidth (fA, fB) or more is separated.

  More preferably, the removal frequency setting unit 12 sets the removal band to (i) the band edge farther from the use frequency band of the frequency band fBand used in the communication system used by the communication device 10a, or ( ii) Move out of band.

The configuration of the communication device 10a according to the present embodiment will be described with reference to FIG. FIG.
It is a block diagram which shows the structure of the communication apparatus 10a which concerns on this embodiment. As illustrated in FIG. 4, the communication device 10 a includes a control unit 1 a in which a transmission / reception determination unit 13 is added to the configuration of the communication device 10 in FIG. 1.

  The transmission / reception determination unit 13 of the control unit 1a determines whether the transmission / reception circuits 5a and 5b are processing transmission / reception signals, and outputs the determination result to the removal frequency setting unit 12. Next, processing of the removal frequency setting unit 12 according to the determination result regarding the transmission / reception circuit 5b of the channel B will be described.

  Based on the determination result, the removal frequency setting unit 12 uses the frequency band fA set in the transmission / reception circuit 5a when the transmission / reception circuit 5a processes the transmission / reception signal and the transmission / reception circuit 5b does not process the transmission / reception signal. A band separated by a predetermined value or more is set as a removal band in the variable band filter unit 4a. Further, the removal frequency setting unit 12 determines that the frequency set in the transmission / reception circuit 5b when the transmission / reception circuit 5a is not processing the transmission / reception signal and the transmission / reception circuit 5b is processing the transmission / reception signal based on the determination result. A band away from the band fB by a predetermined value or more is set as a removal band in the variable band filter unit 4b.

  When one of the transmission / reception circuits 5a and 5b is not processing a signal, it is not necessary to consider the influence of the signal from the other transmission / reception circuit on the one transmission / reception circuit. Therefore, the frequency band removed by the variable band filter unit connected to the other transmission / reception circuit is moved to a frequency band that is more than a predetermined value away from the use frequency band of the other transmission / reception circuit. Accordingly, the band elimination filter connected to the other transmission / reception circuit can transmit almost all signals in the use frequency band of the other transmission / reception circuit, thereby reducing transmission loss and reducing the C / The N ratio can be ensured.

(Modification)
The transmission / reception determination unit (quality determination means) 13 determines whether or not the C / N ratio of the transmission / reception circuits 5a and 5b satisfies a standard (whether or not it is a predetermined value or more), that is, whether or not the communication quality is good. The determination result may be output to the removal frequency setting unit 12.

  In this case, if the communication quality in the transmission / reception circuit 5a does not satisfy the predetermined standard and the communication quality in the transmission / reception circuit 5b satisfies the predetermined standard, the removal frequency setting unit 12 sets the transmission / reception circuit 5a. A band that is a predetermined value or more away from the frequency band fA that has been set is set as a removal band in the variable band filter unit 4a. Further, the removal frequency setting unit 12 determines that the communication frequency in the transmission / reception circuit 5a satisfies a predetermined standard and the frequency set in the transmission / reception circuit 5b when the communication quality in the transmission / reception circuit 5b does not satisfy the predetermined standard. A band away from the band fB by a predetermined value or more is set as a removal band in the variable band filter unit 4b.

  When the communication quality of one of the transmission / reception circuits 5a and 5b is sufficiently high, it is not necessary to consider the influence of the signal from the other transmission / reception circuit on the one transmission / reception circuit. Therefore, the frequency band removed by the variable band filter unit connected to the other transmission / reception circuit is moved to a frequency band that is more than a predetermined value away from the use frequency band of the other transmission / reception circuit. Accordingly, the band elimination filter connected to the other transmission / reception circuit can transmit almost all signals in the use frequency band of the other transmission / reception circuit, thereby reducing transmission loss and reducing the C / The N ratio can be ensured.

[Embodiment 3]
Next, a communication device 10b according to Embodiment 3 of the present invention will be described. The communication device 10b according to the third embodiment of the present invention includes a transmission / reception determination unit 13 that determines whether each of the transmission / reception circuits 5a and 5b processes a signal, and a transmission / reception determination unit 13 that includes the transmission / reception circuits 5a and 5b. When it is determined that only one of the transmission / reception circuits is processing a signal, the apparatus further includes a bypass path setting unit that bypasses the corresponding band removal filter unit and connects the corresponding transmission / reception circuit to the corresponding antenna. This is different from the first embodiment.

  The configuration of the communication device 10b according to the present embodiment will be described with reference to FIG. FIG. 5 is a block diagram illustrating a configuration of the communication device 10b according to the present embodiment. As illustrated in FIG. 5, the communication device 10 b includes a transmission / reception determination unit (processing determination unit, quality determination unit) 13 and a bypass path setting unit 14 (bypass control unit) in addition to the configuration of the communication device 10 in FIG. 1. The control unit 1a, the variable band filter unit 4c added with the filter path 41c and the bypass path 42c (first band elimination filter unit), and the variable band filter unit 4d added with the filter path 41d and the bypass path 42d ( A second band elimination filter unit).

  The transmission / reception determination unit 13 of the control unit 1b determines whether the transmission / reception circuits 5a and 5b are processing transmission / reception signals, and outputs the determination result to the removal frequency setting unit 12 and the bypass path setting unit 14. The transmission / reception determination unit 13 determines whether or not the C / N ratio of the transmission / reception circuits 5a and 5b is equal to or higher than a predetermined value, that is, whether or not the communication quality is good, and the determination result is used as the removal frequency setting unit 12. And may be output to the bypass path setting unit 14.

  The processing of the removal frequency setting unit 12 according to the determination result is the same as in the first embodiment.

  Based on the determination result, the bypass path setting unit 14 determines whether the transmission / reception circuit 5a is processing the transmission / reception signal and the transmission / reception circuit 5b is not processing the transmission / reception signal. Instruct to switch from 41c to bypass path 42c. The matching circuit 3a and the transmission / reception circuit 5a may be directly connected by bypassing the variable band filter unit 4c itself. In addition, the bypass path setting unit 14 determines that the variable band filter unit 4d indicates that the transmission / reception circuit 5a does not process the transmission / reception signal and the transmission / reception circuit 5b processes the transmission / reception signal based on the determination result. The switch path 41d is instructed to switch to the bypass path 42d. The matching circuit 3b and the transmission / reception circuit 5b may be directly connected by bypassing the variable band filter unit 4d itself.

  When one of the transmitting / receiving circuits 5a and 5b is not processing a signal, it is not necessary to consider the influence of the signal from the other transmitting / receiving circuit on the one transmitting / receiving circuit. In view of this, the other transmission / reception circuit can be connected to the antenna by bypassing the corresponding variable band filter section, thereby reducing the transmission loss and ensuring the C / N ratio of the signal.

(Modification)
The transmission / reception determination unit (quality determination means) 13 determines whether or not the C / N ratio of the transmission / reception circuits 5a and 5b satisfies a standard (whether or not it is a predetermined value or more), that is, whether or not the communication quality is good. The determination result may be output to the removal frequency setting unit 12.

In this case, when the communication quality in the transmission / reception circuit 5a does not satisfy the predetermined standard and the communication quality in the transmission / reception circuit 5b satisfies the predetermined standard based on the determination result, the bypass path setting unit 14 determines the variable band filter unit 4c. To switch from the filter path 41c to the bypass path 42c. The matching circuit 3a and the transmission / reception circuit 5a may be directly connected by bypassing the variable band filter unit 4c itself. From the determination result, the bypass path setting unit 14 determines that the communication quality in the transmission / reception circuit 5a satisfies a predetermined standard and the communication quality in the transmission / reception circuit 5b does not satisfy the predetermined standard, the variable path filter unit 4d Instruct to switch from the filter path 41d to the bypass path 42d. The matching circuit 3b and the transmission / reception circuit 5b may be directly connected by bypassing the variable band filter unit 4d itself.

  When the communication quality of one of the transmission / reception circuits 5a and 5b is sufficiently high, it is not necessary to consider the influence of the signal from the other transmission / reception circuit on the one transmission / reception circuit. In view of this, the other transmission / reception circuit can be connected to the antenna by bypassing the corresponding variable band filter section, thereby reducing the transmission loss and ensuring the C / N ratio of the signal.

[Example of software implementation]
1, 4 and 5 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be implemented by a CPU (Central Processing).
Unit) and may be realized by software.

  In the latter case, the control unit 1 includes a CPU that executes instructions of a program that is software that implements each function, a ROM (Read Only Memory) in which the program and various data are recorded so as to be readable by a computer (or CPU), or A storage device (these are referred to as “recording media”), a RAM (Random Access Memory) for expanding the program, and the like are provided. And the objective of this invention is achieved when a computer (or CPU) reads the said program from the said recording medium and runs it. As the recording medium, a “non-temporary tangible medium” such as a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. The program may be supplied to the computer via an arbitrary transmission medium (such as a communication network or a broadcast wave) that can transmit the program. The present invention can also be realized in the form of a data signal embedded in a carrier wave in which the program is embodied by electronic transmission.

[Summary]
The communication apparatus according to the first aspect of the present invention includes a first transmission / reception unit (transmission / reception unit) that processes signals transmitted / received by the first and second antennas (antennas 2a and 2b) and the first and second antennas, respectively. Circuit 5a, 5b), the first and second band removal which are interposed between the first antenna and the first transmission / reception unit and between the second antenna and the second transmission / reception unit, respectively, and whose removal band is variable. Filter unit (variable band filter units 4a to 4d), setting means (transmission / reception frequency setting unit 11) for setting different use frequency bands in the first and second transmission / reception units, and the first band removal filter unit are the second transmission / reception units Control means (removal frequency setting unit 12) for controlling the first and second band removal filter units so that the second band removal filter unit removes the use frequency band of the first transmission / reception unit. Is provided.

According to the above configuration, (i) the signal transmitted from the first transmission / reception unit and radiated from the first antenna has the frequency band used by the second transmission / reception unit reduced by the first band elimination filter unit, ii) Since the signal received by the second antenna is input to the second receiving unit in a state where the use frequency band of the first transmitting / receiving unit is reduced by the second band elimination filter unit, (iii) the first and second Reduces the strong input level in the operating frequency band of the first transmitting / receiving unit and the base level in the operating frequency band of the second transmitting / receiving unit in the signal derived from the first transmitting / receiving unit that enters the second transmitting / receiving unit through the antenna. can do. Similarly, (i) the signal transmitted from the second transmitting / receiving unit and radiated from the second antenna has the frequency band used by the first transmitting / receiving unit reduced by the second band elimination filter unit, and (ii) the first Since the signal received by the antenna is input to the first receiving unit with the use frequency band of the second transmitting / receiving unit reduced by the first band removing filter unit, (iii) wraps around the first and second antennas. The strong input level in the used frequency band of the second transmitting / receiving unit and the base level in the used frequency band of the first transmitting / receiving unit in the signal derived from the second transmitting / receiving unit input to the first transmitting / receiving unit can be reduced. . Thereby, it is possible to successfully prevent interference between antennas due to wraparound of radio waves.

  In the communication device according to aspect 2 of the present invention, in the aspect 1, the processing determination unit (transmission / reception determination unit 13) that determines whether each of the first transmission / reception unit and the second transmission / reception unit processes the signal is provided. In addition, when the processing determination unit determines that only one of the first and second transmission / reception units processes the signal, the control unit is connected to the one transmission / reception unit. The removal band of the band removal filter unit may be moved to a frequency band that is a predetermined value or more away from the use frequency band of the one transmission / reception unit.

  According to said structure, when one transmission / reception part is not processing a signal among the 1st transmission / reception part and the 2nd transmission / reception part, the influence of the signal from the other transmission / reception part with respect to the said one transmission / reception part is affected. There is no need to consider. Therefore, the frequency band removed by the band elimination filter unit connected to the other transmission / reception unit is moved to a frequency band separated from the use frequency band of the other transmission / reception unit by a predetermined value or more. Accordingly, the band elimination filter connected to the other transmission / reception unit can transmit almost all signals in the used frequency band of the other transmission / reception unit, thereby reducing transmission loss and reducing the C / The N ratio can be ensured.

  The communication apparatus according to aspect 3 of the present invention is the communication apparatus according to aspect 1, in which the processing determination unit that determines whether each of the first and second transmission / reception units processes the signal, and the processing determination unit When it is determined that only one of the first and second transmission / reception units processes the signal, the one transmission / reception unit is connected to the corresponding antenna by bypassing the corresponding band elimination filter unit. A bypass control means (bypass path setting unit 14) may be further provided.

  According to said structure, when one transmission / reception part is not processing a signal among the 1st transmission / reception part and the 2nd transmission / reception part, the influence of the signal from the other transmission / reception part with respect to the said one transmission / reception part is affected. There is no need to consider. Therefore, the transmission / reception loss can be reduced and the C / N ratio of the signal can be secured by bypassing the band elimination filter unit and connecting the other transmission / reception unit to the antenna.

  A communication device according to aspect 4 of the present invention, in the above-described aspects 2 and 3, determines whether or not the communication quality of each of the first transmission / reception unit and the second transmission / reception unit satisfies a predetermined standard instead of the processing determination unit. A quality judging unit (transmission / reception judging unit 13) for judging, wherein the one of the transmitting / receiving units has a communication quality of only one of the first and second transmitting / receiving units among the first and second transmitting / receiving units; May be one of the transmission / reception units.

  According to said structure, when the communication quality of one transmission / reception part is high enough among the 1st transmission / reception part and the 2nd transmission / reception part, the influence of the signal from the other transmission / reception part with respect to the said one transmission / reception part is considered. do not have to. Therefore, the frequency band removed by the band elimination filter unit connected to the other transmission / reception unit is moved to a frequency band separated from the use frequency band of the other transmission / reception unit by a predetermined value or more. Accordingly, the band elimination filter connected to the other transmission / reception unit can transmit almost all signals in the used frequency band of the other transmission / reception unit, thereby reducing transmission loss and reducing the C / The N ratio can be ensured.

  Moreover, when the communication quality of one transmission / reception part is high enough among the 1st transmission / reception part and the 2nd transmission / reception part, it is not necessary to consider the influence of the signal from the other transmission / reception part with respect to the said one transmission / reception part. Therefore, the transmission / reception loss can be reduced and the C / N ratio of the signal can be secured by bypassing the band elimination filter unit and connecting the other transmission / reception unit to the antenna.

A communication apparatus according to aspect 5 of the present invention includes a first antenna, a second antenna, a transmission unit that processes a signal transmitted by the first antenna, a reception unit that processes a signal received by the second antenna, a first antenna, The first and second band elimination filter units, the first and second transmission / reception units, which are interposed between the transmission unit and between the second antenna and the reception unit and whose removal band is variable, are connected to each other. Setting means for setting different use frequency bands, and the first band removal filter unit removes the use frequency band of the second transmission / reception unit, and the second band removal filter unit removes the use frequency band of the first transmission / reception unit. The control means for controlling the first and second band elimination filter units may be provided.

  According to the above configuration, (i) a signal output from the transmission unit and radiated from the first antenna has a use frequency band of the reception unit reduced by the first band removal filter unit, and (ii) a second Since the signal received by the antenna is input to the receiving unit in a state where the frequency band used by the transmitting unit is reduced by the second band elimination filter unit, (iii) wraps around the first and second antennas to the receiving unit. It is possible to reduce the strong input level in the use frequency band of the transmission unit and the base level in the use frequency band of the reception unit in the input signal derived from the transmission unit. Thereby, it is possible to successfully prevent interference between antennas due to wraparound of radio waves.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

  The present invention can be used for a communication device including two antennas.

1 Control unit 2a, 2b Antenna (first antenna, second antenna)
4a, 4b, 4c, 4d Variable band filter unit (first band removal filter unit, second band removal filter unit)
5a, 5b Transmission / reception circuit (transmission unit, reception unit, first transmission / reception unit, second transmission / reception unit)
10, 10a, 10b Communication device 11 Transmission / reception frequency setting unit (setting means)
12 Removal frequency setting section (control means)
13 Transmission / reception determination unit (processing determination means, quality determination means)
14 Bypass path setting unit (bypass control means)

Claims (5)

First and second antennas,
First and second transmission / reception units for processing signals transmitted and received by the first and second antennas, respectively;
A first and second band elimination filter unit that is interposed between the first antenna and the first transmission / reception unit and between the second antenna and the second transmission / reception unit, and whose removal band is variable;
Setting means for setting different use frequency bands in the first and second transmission / reception units, and the first band removal filter unit removes the use frequency band of the second transmission / reception unit, and the second band removal filter unit is the first transmission / reception unit. A communication device comprising control means for controlling the first and second band removal filter units so as to remove the used frequency band. Processing decision means for judging whether or not each of the first transmission / reception unit and the second transmission / reception unit processes the signal,
When the processing determination means determines that only one of the first and second transmission / reception units is processing the signal, the control means is a band elimination filter connected to the one transmission / reception unit. The communication apparatus according to claim 1, wherein a removal band of the first part is moved to a frequency band that is a predetermined value or more away from a use frequency band of the one transmission / reception part. Processing determination means for determining whether or not each of the first and second transmission / reception units processes the signal, and the processing determination means is configured such that only one of the first and second transmission / reception units transmits and receives the signal. 2. The apparatus according to claim 1, further comprising: a bypass control unit configured to connect the one transmitting / receiving unit to a corresponding antenna by bypassing the corresponding band elimination filter unit when it is determined that the one transmitting / receiving unit is processing. Communication equipment. In place of the processing determination unit, the first determination unit includes a quality determination unit that determines whether each communication quality of the first transmission / reception unit and the second transmission / reception unit satisfies a predetermined standard,
The one transmission / reception unit is the one transmission / reception unit when the quality determination unit determines that the communication quality of only one of the first and second transmission / reception units satisfies a predetermined standard. The communication apparatus according to claim 2 or 3, wherein First and second antennas,
A transmitter for processing a signal transmitted by the first antenna;
A receiver for processing a signal received by the second antenna;
First and second band elimination filter units that are interposed between the first antenna and the transmission unit and between the second antenna and the reception unit, respectively, and whose removal band is variable,
Setting means for setting different use frequency bands in the first and second transmission / reception units, and the first band removal filter unit removes the use frequency band of the second transmission / reception unit, and the second band removal filter unit is the first transmission / reception unit. A communication device comprising control means for controlling the first and second band removal filter units so as to remove the used frequency band.

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