JP2004048200A - Wireless relay apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless relay apparatus that reduces a passing loss of a delay unit and promotes downsizing and weight reduction of the delay unit. <P>SOLUTION: One delay unit 7 is adopted for delay units having been respectively provided to a downlink main line system and an uplink main line system to provide a fixed delay of one chip or over of a spread code in the code division multiple access system. The downlink main line system and the uplink main line system share the delay unit 7, and the amount of delay of a delay unit 12a of a downlink suppression system and the amount of delay of a delay unit 12b of an uplink suppression system are separately selected. The delay units 12a, 12b are separately provided to the uplink and downlink suppression systems. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a radio relay apparatus used for a mobile communication system, particularly for eliminating a dead zone between a base station and a mobile station or expanding a cover area.
[0002]
[Prior art]
Conventionally, in mobile communication systems and the like, there are places where radio waves are relatively difficult to reach between base stations and mobile stations, such as in mountainous areas, in plains, in buildings or in tunnels. In this case, a wireless relay device is used. In addition, the wireless relay device is used for expanding the area of the wireless zone.
[0003]
As this wireless relay device, there is an RF repeater device that relays a received signal as it is, that is, a high-frequency signal using a code division multiple access system or a code division multiplex system. This RF repeater is a device that is cost-effective because it relays high-frequency signals as they are.
[0004]
FIG. 3 is a diagram illustrating a schematic configuration of a mobile communication system using a wireless relay device that covers a dead zone. In FIG. 3, the base station 100 and the mobile station 101 cannot perform direct communication because the mobile station 101 is located in the dead zone 103. The wireless relay device 200 relays communication between the base station 100 and the mobile station 101. The radio relay apparatus 200, the downstream signal _{f D} from the base station 100 received by antenna 201a, amplifies the downstream signal _{f D} is transmitted from the antenna 201b to the mobile station 101. On the other hand, the uplink signal _{f U} from the mobile station 101 is received by the antenna 201b, is transmitted from antenna 201a amplifies the uplink signal _{f U} to the base station 100.
[0005]
Here, the wireless relay device 200 as the RF repeater device is installed so that the isolation between the antennas 201a and 201b is higher than the repeater gain in order to amplify and radiate a high-frequency signal of the same frequency as it is. However, due to restrictions on the installation of the RF repeater device, such as the inability to sufficiently separate the transmitting and receiving antennas, isolation between the transmitting and receiving antennas may not be sufficiently obtained. If the repeater gain is higher than the isolation between them, a problem of oscillation occurs.
[0006]
For this reason, as shown in FIG. 4, the wireless relay apparatus 200 is provided with an interference suppression circuit 220 for suppressing the sneak signals Sa and Sb. FIG. 4 is a block diagram illustrating a detailed configuration of the wireless relay device 200. In FIG. 4, the radio relay apparatus 200 is an RF repeater apparatus, and a downlink reception signal from the base station 100 is received by an antenna 201a, passed through a circulator 202a, and becomes a directional coupler 203a as a downlink main line signal _SD. Is input to The directional coupler 203a is combined with the downstream suppression system signal S _DX which is a interference suppression signal described later, canceling the echo signal Sa component of the downlink main line system in the signal S _D.
[0007]
The downstream main line signal _SD is then input to the low noise amplifier 204a, amplified, and input to the delay unit 206a via the directional coupler 205a. The delay unit 206a gives a delay of one chip or more, for example, 750 nsec or more in a 800 MHz band wideband code division multiple access system. Furthermore, the downstream main line system signal S _D is power-amplified by the power amplifier 207a, branches a part of the downstream main line system signal S _D via the directional coupler 208a as a downlink suppression system signal S _DX. The downlink main line signal _SD radiates the downlink main line signal _SD from the antenna 201b via the circulator 202b, and a part of the signal flows to the antenna 201a as a loop signal Sa.
[0008]
Are downlink suppression system signal S _DX is branched from the directional coupler 208a, is input to the delay unit 210a via a directional coupler 209a, wraparound delay amount corresponding to the delay difference of the signals Sa and the downstream suppression system signal S _DX Is added. Thereafter, the downstream suppression system signal _{S DX} is input to the variable phase shifter 211a and variable attenuator 212a. Here, part of a part from the directional coupler 205a of the downstream main line system signal S _D and the directional coupler 209a of the downstream suppression system signal S _DX is input to the digital signal processing unit C2a. The digital signal processing unit C2a the downstream suppression system signal S _DX is, so as to obtain echo signal Sa and the same amplitude and opposite phase, the attenuation amount of phase shift and attenuator 212a of the phase shifter 211a variably adjusted. Thus, the downstream suppression system signal S _DX to cancel the echo signal Sa is generated, is output to the directional coupler 203a, interference suppression of echo signal Sa is performed. Note that the upward main line system signal S _U received from the antenna 201b is also generated uplink suppression system signal S _UX, interference suppression by the upstream suppression system signal S _UX runs.
[0009]
[Problems to be solved by the invention]
Here, in the above-described conventional wireless relay device, when the delay units 206a and 206b provide a delay of 750 nsec or more, for example, by a coaxial cable, a length of 100 m or more is required. For example, in the case of a coaxial cable having a delay of 5 μsec / km, a delay of 750 nsec is obtained at 150 m. The delay using the coaxial cable has a problem that the storage space becomes enormous and it is not possible to promote the reduction in size and weight of the wireless relay device. For this reason, it is conceivable to obtain a delay of 750 nsec by using the SAW filter, but there is a problem that the passage loss increases.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to provide a wireless relay apparatus which can reduce the passing loss of a delay unit and can promote a reduction in size and weight in order to solve the above-described problems of the related art.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem and achieve the object, a wireless relay device according to claim 1 amplifies a transmission signal having the same frequency as a first reception signal received from a first antenna by a first amplification unit. A first relay means for transmitting from the second antenna, and a transmission signal having the same frequency as the second reception signal received from the second antenna, amplified by the second amplifying means and transmitted from the first antenna. Second relaying means, first interference suppressing means for suppressing interference by a first loop-back signal from the second antenna to the first antenna, and a second antenna from the first antenna to the second antenna. And a second interference suppressor for suppressing interference caused by a second loop-back signal to the wireless communication apparatus, wherein the first and second amplifying means include one chip of a spread code in a code division multiple access system. A chip delay unit for providing the above-described delay amount and shared by the first and second amplifying units, wherein the first and second interference suppressing units are configured to provide a part of the signal delayed by the chip delay unit. A delay amount corresponding to a delay difference between the first and second interference suppression signals extracted as described above and the first and second wraparound signals is assigned to the first and second interference suppression signals, respectively. The phase and amplitude of the first and second interference suppression signals are controlled so that the first and second wraparound signals can be canceled, respectively.
[0012]
According to the invention of claim 1, the first and second amplifying means share a chip delay means for giving a delay amount of one or more chips of a spread code in a code division multiple access system, and the wireless relay apparatus Can be reduced in size and weight.
[0013]
Also, in the wireless relay device according to claim 2, in the above invention, the first and second interference suppressing means are each provided as a part of a signal delayed by the chip delay means. A delay amount corresponding to a delay difference between the interference suppression signal of the first and second and the first and second wraparound signals is added to the first and second interference suppression signals, and the first and second interference suppression means share the delay amount. A delay means for performing the operation.
[0014]
According to the second aspect of the present invention, the first and second interference suppression means pay attention to the fact that the delay amounts of the first and second wraparound signals are substantially the same, and the first and second interference suppression means The delay means for providing a delay amount corresponding to the delay difference between the interference suppression signal and the first and second wraparound signals is shared, and the size and weight of the wireless relay device can be further reduced.
[0015]
Further, in the wireless relay device according to claim 3, in the above invention, the chip delay means or the delay means has a filter in the same frequency band as the first received signal and in the same frequency band as the second received signal. Are provided in the signal input section and the signal output section.
[0016]
According to the third aspect of the present invention, the chip delay unit and / or the delay unit provide the signal input unit and the signal output unit with the same frequency band as the first received signal and the same frequency band as the second received signal. Is provided so that the first received signal and the second received signal are distinguished sharply, so that the first and second received signals can be reliably relayed.
[0017]
Further, in the wireless relay device according to claim 4, in the above invention, the chip delay unit or the delay unit converts the input electric signal into an optical signal, and converts the output optical signal into an optical signal. It is characterized by comprising photoelectric conversion means for converting into an electric signal, and an optical fiber cable for delay connected between the electric light conversion means and the photoelectric conversion means.
[0018]
According to the fourth aspect of the present invention, the chip delay unit or the delay unit converts the input electric signal into an optical signal, and the opto-electric conversion unit converts the output optical signal into an electric signal. An optical fiber cable for delay is connected between these means, and the size and weight are further promoted as compared with the coaxial cable, and the number of expensive electro-optical conversion means and the number of parts of the opto-electric conversion means can be reduced. It is possible to reduce the size and weight and to reduce the cost.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
A wireless relay device and an interference suppression device according to the present invention will be described below with reference to the accompanying drawings.
[0020]
(Embodiment 1)
First, a first embodiment of the present invention will be described. FIG. 1 is a block diagram showing a configuration of the wireless relay device according to the first embodiment of the present invention. In this wireless relay device, the delay units 206a and 206b in the wireless relay device shown in FIG. 4 are combined into one delay unit, and are to be shared in uplink and downlink relay processing.
[0021]
In FIG. 1, this radio relay apparatus is used in a part of a mobile radio communication system adopting a wideband code division multiple access system, and includes an antenna 1a wirelessly connected to a base station (not shown), and a radio connection between a mobile station (not shown). An antenna 1b, circulators 2a and 2b respectively connected to the antennas 1a and 1b, a downstream main line connected between the circulators 2a and 2b for amplifying and relaying the downstream main line signal _SD , and an upstream main line and up main line system for amplifying relay processing system signals S _DX, and down suppressing system for performing interference suppression processing by the signal Sa wraparound downlink main line system signal S _D, interference suppression processing by the signal Sb sneak the upward main line system signal S _U , A digital signal processing unit Ca for controlling the downlink suppression system, and a digital signal processing unit Cb for controlling the uplink suppression system. I do.
[0022]
In the downstream main line system and the upstream main line system, directions in which the downstream main line signal S _D , the upstream main line signal S _U , the downstream suppression system signal S _DX , and the upstream suppression system signal S _UX are input from the circulators 2a and 2b and combined. Sexual couplers 3a and 3b, low-noise amplifiers 4a and 4b for low-noise amplification of output signals from directional couplers 3a and 3b, respectively, and a part of the low-noise-amplified signal is converted into digital signal processing units Ca and directional coupler 5a to output to the digital signal processing unit Cb, 5b and downlink principal line system signal S _D, the filter 6a that passes each signal band of the uplink main line system signals S _U, 6b and, downstream main line system signal S _D and upward main line system signal S _U a delayer 7 to impart commonly one chip or more delay respectively, pass down the main line system signal S _D, the signal band of the uplink main line system signal S _U respectively Filter 8a to, 8b and the filter 8a, the power amplifier 9a for each power amplifying a signal outputted from 8b, 9b and the power amplifier 9a, down main line system is output from 9b signal _{S D,} upward main line system signal _{S U} Directional couplers 10a and 10b which take out a part of the signals and output them to the downlink suppression system and the uplink suppression system, respectively, the downlink main line signal S _D and the uplink main line signal S _U output from the directional couplers 10a and 10b. Is output to the antennas 1b and 1a via the circulators 2b and 2a, respectively.
[0023]
Downstream suppression system and the up suppression system output, a directional coupler 10a, the downstream suppression signal S _DX branched from _10b, a portion of the respective digital signal processor unit Ca, a digital signal processor Cb upstream suppression system signal S _UX Directional couplers 11a, 11b, and wrap-around signals Sa, Sb and downlink suppression-system signal S _DX , and downlink suppression-system signal S _DX , from downlink coupler-system signals S _DX and uplink suppression-system signal S _UX from directional couplers 11a, 11b, respectively. signal S _UX delayer 12a delaying delayed corresponding to the delay difference, 12b and a digital signal processor Ca, under the control of the digital signal processing unit Cb, a downlink suppression system signal S _DX, upstream suppression system signal phase shifter 13a to the variable phase the phase of S _UX, and 13b, the downstream suppression system signal _{S DX,} attenuators 14a to the variable attenuation of the amplitude of the uplink suppression system signal _{S UX,} and 14b And a variable adjusted downlink suppression system signal S _DX, upstream suppression system signal S _UX Each directional coupler 3a, is output to 3b.
[0024]
As described above, this wireless relay device is an RF repeater device, amplifies the received downlink signal as a high-frequency signal without performing regenerative relay, and radiates and outputs the amplified downstream signal. The frequency of the down main line system signal S _D and the upward main line system signal S _U is different. Also, the frequency of the downlink signal received by the antenna 1a is the same as the frequency of the downlink signal transmitted by the antenna 1b, and the frequency of the uplink signal received by the antenna 1b is the same as the frequency of the uplink signal transmitted by the antenna 1a. is there.
[0025]
Here, the digital signal processor Ca, Cb are directional couplers 5a, the down main line system signal _{S D} from 5b, upward main line system signal _{S U} and the directional coupler 11a, the downstream suppression system signal _{S DX} from 11b performs correlation calculation between the up suppression system signal S _UX, so the correlation value is output from this correlation operation is reduced, attenuators 14a, 14b and the phase shifter 13a, and 13b is variably controlled. This correlation operation is performed in order to know the amplitude value and phase value of the wraparound signal Sa that fluctuated in the propagation space.
[0026]
The reason why the delay of one chip or more is provided in the delay unit 7 is that when this delay is not provided, the correlation value between the wraparound signals Sa and Sb and the received desired signal increases, and only the wraparound signals Sa and Sb are provided. Can no longer be canceled. That is, by giving a delay of one chip or more, the correlation between the desired signal and the loop-back signal is eliminated, and only the interference signal component in the received signal is canceled.
[0027]
The delay unit 7 includes an electro-optical converter 21 that converts an electric signal into an optical signal, an opto-electric converter 22 that converts an optical signal into an electric signal, and a circuit between the electro-optical converter 21 and the opto-electric converter 22. And an optical fiber cable 23 for providing the above-described delay amount of one chip or more. The delay unit 12a includes an electro-optical converter 24 that converts an electric signal into an optical signal, an opto-electric converter 25 that converts an optical signal into an electric signal, and the electro-optical converter 24 and the opto-electric converter 25. And an optical fiber cable 26 for providing an amount of wraparound delay of the wraparound signal Sa. Further, the delay unit 12b includes an electro-optical converter 27 that converts an electric signal to an optical signal, an opto-electric converter 28 that converts an optical signal to an electric signal, and an electro-optical converter 27 and an opto-electric converter 28. And an optical fiber cable 29 for providing an amount of wraparound delay of the wraparound signal Sb.
[0028]
Here, the first embodiment to the delay device 7 which is a characteristic, different frequencies f _D, and the downward main line system signal S _D and the upward main line system signal S _U is f _U is input, the same one chip or more delay but is applied, for input and output distributing them downstream main line system input filter of the signal S _D, the filter 6a as an output filter, 8a are provided respectively, upward main line system signal S _U of the input filter, output filter Are provided as filters 6b and 8b, respectively. As a result, the delay units conventionally provided in the downstream main line system and the upstream main line system can be shared as one delay unit 7. Possible because this sharing includes a loop signal Sa, Sb and the delay amount is irrelevant, and the down main line system signal S _D and the upward main line system signal S _U is because it there is more than one chip delay. This sharing promotes reduction in size and weight of the entire wireless relay device. The above-described delay unit 7 may be a coaxial cable because the storage space is reduced to half, but it is preferable to use the optical fiber cable 23 from the viewpoint of promoting reduction in size and weight. Although the delay units 12a and 12b are separately provided, a coaxial cable may be used in place of the optical fiber cable if the amount of wraparound delay is small. Further, a SAW filter may be used. In the case of a coaxial cable, for example, it may be about several tens of meters.
[0029]
In the above-described first embodiment, the digital signal processing units Ca and Cb are provided separately. However, the present invention is not limited thereto, and the digital signal processing units Ca and Cb may be shared as one digital signal processing unit.
[0030]
In the first embodiment, since the delay units respectively provided in the downstream main line system and the upstream main line system are shared as one delay unit 7, the reduction in size and weight is promoted, and the use of an optical fiber cable is particularly preferable. Thus, the passage loss can be reduced, and the reduction in size and weight can be further promoted.
[0031]
(Embodiment 2)
Next, a second embodiment of the present invention will be described. In the first embodiment described above, only the delay units of the downlink main line system and the uplink main line system are shared, but in the second embodiment, the delay units of the downlink suppression system and the uplink suppression system are also shared. Things.
[0032]
FIG. 2 is a block diagram showing a configuration of the wireless relay device according to the second embodiment of the present invention. This wireless relay apparatus is provided with one delay unit 12 instead of the delay units 12a and 12b shown in FIG. 1, and further corresponds to each frequency band of the downlink suppression system signal _SDX and the uplink suppression system signal _SUX . An input filter and an output filter for distribution are provided before and after the delay unit 12 as filters 40a and 41a and filters 40b and 41b, respectively. Other configurations are the same as those of the first embodiment, and the same components are denoted by the same reference numerals.
[0033]
Here, the delay units 12 need to be provided corresponding to the delay amounts of the wraparound signals Sa and Sb, respectively, and although the wraparound signals Sa and Sb themselves have different frequency bands, the arrangement relationship of the antennas 1a and 1b is the same. Therefore, the wraparound delay amounts are almost the same. As a result, the delay units 12a and 12b are shared as one delay unit 12.
[0034]
In the second embodiment, not only each delay unit of the downstream main line system and the upstream main line system is shared as one delay unit 7, but also each delay unit of the downstream suppression system and the upstream suppression system is used as one delay unit. Since they are shared, the size and weight of the wireless relay device can be further promoted.
[0035]
In each of the first and second embodiments, the multipaths of the sneak signals Sa and Sb are not taken into consideration. However, a number of suppression system circuits corresponding to the number of multipaths are provided. It is also possible to combine each interference suppression signal from the circuit with a signal of the downstream main line or a signal of the upstream main line via a combiner that combines the interference suppression signals to cancel the wraparound signal of each multipath. In this case, in many cases, the delay amounts of the delay units of the downlink suppression system and the uplink suppression system are almost the same in each multipath. Therefore, the delay units of the downlink suppression system and the uplink suppression system are shared as one delay unit. You may do so.
[0036]
【The invention's effect】
As described above, according to the first aspect of the present invention, the first and second amplifying means commonly apply a delay amount of one or more chips of a spread code in a code division multiple access system. And the wireless relay device can be reduced in size and weight.
[0037]
According to the second aspect of the present invention, the first and second interference suppressing means pay attention to the fact that the delay amounts of the first and second wraparound signals are substantially the same, and In this case, the delay means for commonly providing the delay amount corresponding to the delay difference between the second interference suppression signal and the first and second loop-back signals is shared, thereby further reducing the size and weight of the wireless relay apparatus. It has the effect of being able to do it.
[0038]
According to the invention of claim 3, the chip delay means and / or the delay means have the same frequency band as the first reception signal and the same frequency band as the second reception signal in the signal input section and the signal output section. Since the filter in the frequency band is provided so as to distinguish the first received signal from the second received signal, there is an effect that the relay processing of the first and second received signals can be reliably performed. .
[0039]
According to the fourth aspect of the present invention, the chip delay unit or the delay unit converts the input electric signal into an optical signal, and converts the output optical signal into an electric signal. By connecting an optical fiber cable for delay between the electric conversion means and the coaxial cable, the size and weight can be further promoted and the number of expensive electro-optical conversion means and the number of parts of the opto-electric conversion means can be reduced. In addition, it is possible to further reduce the size and weight and to reduce the cost.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a wireless relay device according to a first embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of a wireless relay device according to a second embodiment of the present invention.
FIG. 3 is a diagram illustrating a schematic configuration of a mobile communication system in which a wireless relay device is used.
FIG. 4 is a block diagram illustrating a configuration of a conventional wireless relay device.
[Explanation of symbols]
1a, 1b Antennas 2a, 2b Circulators 3a, 3b, 5a, 5b, 10a, 10b, 11a, 11b Directional Couplers 4a, 4b Low Noise Amplifiers 6a, 6b, 8a, 8b, 40a, 40b, 41a, 41b Filter 7 , 12, 12a, 12b Delay devices 9a, 9b Power amplifiers 13a, 13b Phase shifters 14a, 14b Attenuators 21, 24, 27, 31 Electro-optical converters 22, 25, 28, 32 Opto-electric converters 23, 26, 29,33 Optical fiber cable _SD Down main line signal S _U Up main line signal S _DX Downstream suppression system signal _SUX Upstream suppression system signal Sa, Sb Sneak signal

Claims (4)

A first relay unit that amplifies a transmission signal having the same frequency as the first reception signal received from the first antenna by the first amplification unit and sends out the transmission signal from the second antenna, and receives the transmission signal from the second antenna; A second relay unit that amplifies a transmission signal having the same frequency as the second reception signal by the second amplification unit and transmits the amplified signal from the first antenna; and a first relay unit configured to transmit a first signal from the second antenna to the first antenna. Wireless communication apparatus comprising: a first interference suppressor for suppressing interference caused by a wraparound signal; and a second interference suppressor for suppressing interference by a second wraparound signal from the first antenna to the second antenna. In the relay device,
The first and second amplifying means include a chip delay means for giving a delay amount of one chip or more of a spread code in a code division multiple access system, and shared by the first and second amplifying means.
The first and second interference suppression units are configured to delay the first and second interference suppression signals extracted as a part of the signal delayed by the chip delay unit and the first and second wraparound signals, respectively. A delay amount corresponding to the difference is added to each of the first and second interference suppression signals, and the first and second interference suppression signals are canceled so that the first and second wraparound signals can be respectively canceled. A wireless relay device for controlling a phase and an amplitude. The first and second interference suppression means include:
The delay amounts corresponding to the delay difference between the first and second interference suppression signals and the first and second wraparound signals, respectively, extracted as a part of the signal delayed by the chip delay means, are defined as the first and second delay signals. The wireless relay device according to claim 1, further comprising a delay unit that is provided to the second interference suppression signal and shared by the first and second interference suppression units. The chip delay means or the delay means,
3. The wireless relay according to claim 1, wherein a filter having the same frequency band as the first received signal and a filter having the same frequency band as the second received signal are provided in the signal input unit and the signal output unit. 4. apparatus. The chip delay means and / or the delay means
Electro-optical conversion means for converting an input electric signal into an optical signal,
Photoelectric conversion means for converting the output optical signal into an electric signal,
An optical fiber cable for delay connected between the electro-optical converter and the opto-electric converter,
The wireless relay device according to any one of claims 1 to 3, further comprising:

Images