Radio repeater

Abstract

To provide a radio repeater that solves the problem of upsizing by combining a system configuration of two systems into one system in an intermediate frequency band.SOLUTION: A radio repeater includes a first unit, a second unit, and one cable connecting the first unit and the second unit. The first unit includes N donor antennas, from a first donor antenna to an Nth donor antenna, that communicate with a base station, where N is an integer equal to or greater than 2, a first connection section connected to an analog cable, and N donor-side frequency conversion sections from a donor-side first frequency conversion section to a donor-side Nth frequency conversion section. The second unit includes N service antennas, from a first service antenna to an Nth service antenna, that communicate with a communication terminal, a second connection section connected to the analog cable, and N service-side frequency conversion sections from a service-side first frequency conversion section to a service-side Nth frequency conversion section.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a wireless repeater, and more particularly to a simple configuration of a wireless repeater for a millimeter-wave band mobile communication system such as the 28 GHz band used in the 5G standard.

Background Art

[0002] When the frequency used for communication increases in standards such as 5G, the directivity of radio waves increases, and it becomes difficult to communicate by radio waves when there are buildings or the like between the base station and the communication terminal. For this reason, wireless repeaters are often used. A wireless repeater is composed of a donor unit that transmits and receives with a base station (BS) and a service unit that transmits with a terminal (UE). For example, it is used when a direct wireless link between the base station and the terminal cannot be formed due to obstacles or the like (Patent Document 1). FIG. 4 of Cited Document 1 shows an example of the configuration of a wireless repeater. In a wireless repeater, in the case of analog wiring, from the viewpoint of reducing feeder loss of a coaxial cable, it is dropped to an intermediate frequency band lower than the radio frequency by frequency conversion and connected. (Patent Document 1). A wireless repeater has a donor unit, a service unit, and a coaxial cable connecting the two. Wireless repeaters for 5G millimeter-wave band mobile communication systems etc. support MIMO. In such a wireless repeater, both the BS / UEs use two antennas for MIMO communication and form two-path wireless links in the same frequency band (fRF). For MIMO communication, two antennas, that is, two paths are required in the wireless repeater as well. Especially when using analog cables such as coaxial cables, if configured as such, two cables are required, resulting in poor installability. If it is digital, the cables can be combined into one, but a digital processing unit is required for each of the donor unit and the service unit, increasing the size of the wireless repeater structure, which also leads to deteriorated installability in this case. In a wireless repeater for a 5G millimeter-wave band mobile communication system or the like, a synchronization function is also utilized. In the 5G and millimeter-wave bands, transmission and reception switching is performed using TDD (Time Division Duplex). Therefore, between the BS / UEs, the transmission and reception switching timing is synchronized using the synchronization signal defined in 5G communication. For synchronization, a so-called synchronization module that demodulates the 5G signal and extracts the synchronization signal is required even in the wireless repeater. This synchronization function is implemented in the intermediate frequency band. However, when wiring the two systems separately, a synchronization module is required for each system, leading to an increase in the size of the device. Here, the transmitted wave from the BS side is such that the synchronization signal can be confirmed in both or either of the two systems. In these wireless repeaters, the two systems are wired separately. For example, in the wireless repeater in the 5G standard, for compatibility with MIMO, as shown in FIGS. 1 and 2, a two-system configuration is used.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a two-system configuration, although only one local signal and intermediate frequency are required, two coaxial cables are needed for the two systems, and two synchronization modules are required. Therefore, including the demodulator, it leads to high cost and an increase in the size of the device. In particular, for minimizing the size of the apparatus, it is advantageous to wire analogously between donor service units. However, two coaxial cables are required, resulting in deteriorated installability. Also, for TDD synchronization of a wireless repeater, it is performed by demodulating a 5G synchronization signal from a base station. Since it is not known from the repeater side which system can acquire the synchronization signal, two sets of synchronization modules are required, leading to an increase in the size of the apparatus. For example, even in the case of a wireless repeater in the 5G standard that supports MIMO, the problem of size increase is solved by combining two system configurations into one in the intermediate frequency band. Also, for example, even in the case of a wireless repeater in the 5G standard that supports MIMO, the problem of size increase is solved by making the local signal switchable by the synchronization signal. Furthermore, even in a configuration where the transmission / reception switching timing is synchronized using a synchronization signal, such as in the case of performing transmission / reception switching by TDD in the millimeter wave band of the 5G standard, the problem that a synchronization module is required for each system when wiring the two systems separately is solved by a configuration that satisfies the above functions with one synchronization module. Other objects of the present invention will also be described in the embodiments for carrying out the invention.

Means for Solving the Problems

[0005] The wireless repeater according to claim 1 of the present invention includes a first unit, a second unit, and one cable connecting the first unit and the second unit, wherein the first unit has, with N being an integer of 2 or more, N donor antennas from a first donor antenna to an Nth donor antenna for communicating with a base station, a first connection part connected to the cable, and N donor-side frequency conversion parts from a donor-side first frequency conversion part to a donor-side Nth frequency conversion part. The N donor-side frequency converters from the donor-side first frequency converter to the donor-side Nth frequency converter each convert a signal of frequency fRF received by the corresponding donor antenna among the N donor antennas from the first donor antenna to the Nth donor antenna into an intermediate signal, which is an analog signal, from the first intermediate signal to the Nth intermediate signal using their respective local signals. The local signals and the intermediate signals have different frequencies for each donor-side frequency converter. The second unit includes N service antennas from the first service antenna to the Nth service antenna that communicate with a communication terminal, a second connection part connected to an analog cable, and N service-side frequency converters from the service-side first frequency converter to the service-side Nth frequency converter. The N service-side frequency converters from the service-side first frequency converter to the service-side Nth frequency converter each convert a signal of frequency fRF received by the corresponding service antenna among the N service antennas from the first service antenna to the Nth service antenna into an intermediate signal, which is an analog signal, from the first intermediate signal to the Nth intermediate signal using their respective local signals. The local signals and the intermediate signals have different frequencies for each service-side frequency converter. The cable passes an intermediate signal, which is an analog signal. The wireless repeater is such that the intermediate signals from the first intermediate signal to the Nth intermediate signal are transmitted in a superimposed manner in one cable. The wireless repeater according to claim 2 of the present invention includes a donor-side combining distributor connected between the donor antenna and the cable, and is the wireless repeater according to claim 1, including a service-side combining distributor connected between the service antenna and the cable. The wireless repeater according to claim 3 of the present invention A donor-side filter connected between the donor antenna and the cable, and The wireless repeater according to claim 1, comprising a service-side filter connected between the service antenna and the cable. The wireless repeater according to claim 4 of the present invention A donor-side combined distributor connected between the donor antenna and the cable, and A service-side combined distributor connected between the service antenna and the cable, A donor-side filter connected between the donor antenna and the cable, and The wireless repeater according to claim 1, comprising a service-side filter connected between the service antenna and the cable. The wireless repeater according to claim 5 of the present invention The donor-side combined distributor and the donor-side filter are integrally configured as a donor-side multiplexer, The wireless repeater according to claim 4, wherein the service-side combined distributor and the service-side filter are integrally configured as a service-side multiplexer. The wireless repeater according to claim 6 of the present invention From the first intermediate signal to the Nth intermediate signal, each has a predetermined bandwidth, The wireless repeater according to claim 1, wherein the band of the Nth intermediate signal is separated from the band of the first intermediate signal by a predetermined band from an adjacent band. The wireless repeater according to claim 7 of the present invention Further comprising a synchronization signal acquisition unit, a donor-side local signal switching unit, and a service-side local signal switching unit, The first unit includes a first demodulator and a first synchronization module connected to the first connection part side, The second unit includes a second demodulator and a second synchronization module connected to the second connection part side, The synchronization signal acquisition unit Based on the result of demodulation in the first demodulator, the donor-side local signal switching unit switches the donor-side local signal to obtain a synchronization signal, or The wireless repeater according to any one of claims 1 to 6, wherein based on the result of demodulation in the second demodulator, the service-side local signal switching unit switches the service-side local signal to obtain a synchronization signal. The wireless repeater according to claim 8 of the present invention The donor-side local signal switching unit and the service-side local signal switching unit each further include a donor-side switching transceiver and a service-side switching transceiver. When one of the donor-side local signal switching unit and the service-side local signal switching unit switches the local signal, a local signal switching signal is transmitted to the other through the donor-side switching transceiver and the service-side switching transceiver. The wireless repeater according to claim 7, wherein the other of the donor-side local signal switching unit and the service-side local signal switching unit selects the frequency of the local signal. With the above configuration, the present invention can transmit two systems with one coaxial cable by sharing the transmission path in the intermediate frequency band, thus realizing simplification of the arrangement. Also, with the above configuration, the present invention can achieve 5G synchronization with a single synchronization module, so it is smaller in size compared to conventional devices. Also, by appropriately switching the local signal, the SN during demodulation can be improved, and stable and efficient synchronization can be realized. Furthermore, with the above configuration, the present invention can not only reduce costs by reducing the number of components, but also achieve miniaturization and performance improvement. Other effects of the present invention will also be described in the mode for carrying out the invention.

Brief Description of the Drawings

[0006]

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Embodiments for Carrying Out the Invention

[0007] FIG. 3, FIG. 4, and FIG. 5 show a configuration example of the wireless repeater 1 in an embodiment of the present invention. In the following example, in some parts, for ease of understanding, an example in which there are two donor antennas 101, 102,,, 10N and two service antennas 201, 202,,, 20N, that is, two systems, will be described, but the same applies to cases where N is 2 or more.

[0008] The wireless repeater 1 includes a first unit 100, a second unit, and one cable 300 connecting the first unit 100 and the second unit. The first unit 100 includes N donor antennas 101, 102,..., 10N where N is an integer of 2 or more, a first connection part 110 connected to the analog cable 300, and N donor-side frequency conversion parts 111, 112,..., 11N from the donor-side first frequency conversion part to the donor-side Nth frequency conversion part. In this embodiment, N is 2.

[0009] The N donor antennas 101, 102,..., 10N are donor antennas 101, 102,..., 10N from the first donor antenna 101, 102,..., 10N to the Nth donor antenna 101, 102,..., 10N that communicate with the base station. The N donor-side frequency conversion parts 111, 112,..., 11N from the donor-side first frequency conversion part to the donor-side Nth frequency conversion part each convert a signal of frequency fRF received by the corresponding donor antenna 101, 102,..., 10N among the N donor antennas 101, 102,..., 10N from the first donor antenna 101, 102,..., 10N to the Nth donor antenna 101, 102,..., 10N into an intermediate signal, which is an analog signal, from the first intermediate signal to the Nth intermediate signal by their respective local signals. Here, the local signals and the intermediate signals have different frequencies for each of the donor-side frequency conversion parts 111, 112,..., 11N.

[0010] The second unit includes N service antennas 201, 202,..., 20N, a second connection part connected to the analog cable 300, and N service-side frequency conversion parts 211, 212,..., 21N from the service-side first frequency conversion part to the service-side Nth frequency conversion part. The N service antennas 201, 202,..., 20N are service antennas 201, 202,..., 20N from the first service antenna 201, 202,..., 20N to the Nth service antenna 201, 202,..., 20N that communicate with the communication terminal.

[0011] The N service-side frequency converters 211, 212, …, 21N from the service-side first frequency converter to the service-side Nth frequency converter each convert a signal of frequency fRF received by the corresponding service antenna among the N service antennas 201, 202, …, 20N from the first service antenna 201, 202, …, 20N to the Nth service antenna 201, 202, …, 20N into an intermediate signal, which is an analog signal, from the first intermediate signal to the Nth intermediate signal using their respective local signals. The local signals and the intermediate signals have different frequencies for each of the service-side frequency converters 211, 212, …, 21N.

[0012] The cable 300 passes the intermediate signal, which is an analog signal, and is a cable 300 that appropriately passes the analog signal. In the configuration as in this embodiment, there is no digital processing unit for the intermediate signal, and thus the digital processing unit is not required. The intermediate signals from the first intermediate signal to the Nth intermediate signal are transmitted in a superimposed manner in one cable 300.

[0013] The meaning of "transmitted in a superimposed manner" in the claims and this description includes a configuration in which there are time zones where they are not superimposed depending on the signal timing, and means that signal processing can be performed without problems even when transmitted in a superimposed manner. The local signals and the intermediate signals do not have to be fixed. That is, they may be integrally configured and have different frequencies for each of the superimposed signals.

[0014] In this embodiment, the signals in the high-frequency band fRF of the two sets of antennas, namely the donor antennas 101, 102, …, 10N and the service antennas 201, 202, …, 20N, are each frequency-converted to another intermediate frequency band with frequencies fIF1 and fIF2 using local signals with frequencies fLO1 and fLO2. Here, fIF1 is smaller than fIF2. Signals in the intermediate frequency band with frequencies fIF1 and fIF2 are superimposed on a single transmission line by an intermediate frequency diplexer in the intermediate frequency band, enabling wiring between donor service units using a single coaxial cable 300. The cable 300 may be a digital cable 300 or wireless communication, but may also be an analog cable 300 such as the coaxial cable 300 as in this embodiment. If it is an analog cable 300, components such as an analog-digital converter are not required, the circuit configuration becomes simple, and the entire device can be miniaturized.

[0015] Figure 6 shows a configuration example of the wireless repeater 1 in an embodiment of the present invention. In this embodiment, the wireless repeater 1 includes a donor-side combining distributor 121 connected between the donor antennas 101, 102,..., 10N and the cable 300, and a service-side combining distributor 221 connected between the service antennas 201, 202,..., 20N and the cable 300.

[0016] Figure 7 shows a configuration example of the wireless repeater 1 in an embodiment of the present invention. In this embodiment, the wireless repeater 1 includes a donor-side filter 122 connected between the donor antennas 101, 102,..., 10N and the cable 300, and a service-side filter 222 connected between the service antennas 201, 202,..., 20N and the cable 300.

[0017] Figure 8 shows a configuration example of the wireless repeater 1 in an embodiment of the present invention. In this embodiment, the wireless repeater 1 includes a donor-side combining distributor 121 connected between the donor antennas 101, 102,..., 10N and the cable 300, a service-side combining distributor 221 connected between the service antennas 201, 202,..., 20N and the cable 300, a donor-side filter 122 connected between the donor antennas 101, 102,..., 10N and the cable 300, and a service-side filter 222 connected between the service antennas 201, 202,..., 20N and the cable 300.

[0018] FIG. 9 shows a configuration example of the wireless repeater 1 in an embodiment of the present invention. In this embodiment, the wireless repeater 1, the donor-side combining distributor 121 and the donor-side filter 122 are integrally configured as the donor-side multiplexer 120. The service-side combining distributor 221 and the service-side filter 222 are integrally configured as the service-side multiplexer 220. In the case of two antennas, it becomes a diplexer in this embodiment. The "multiplexer" in the claims and this description includes a diplexer.

[0019] In an embodiment of the present invention, the first unit 100 includes a first demodulator 131 and a first synchronization module 132 connected to the first connection part 110 side. The first synchronization module 132 switches the donor-side frequency conversion parts 111, 112 and the local signal based on the demodulation result in the first demodulator 131. In an embodiment of the present invention, the second unit includes a second demodulator 231 and a second synchronization module 232 connected to the second connection part side. The second synchronization module 232 switches the service-side frequency conversion parts 211, 212 and the local signal based on the demodulation result in the second demodulator 231.

[0020] FIG. 10 shows a configuration example of the wireless repeater 1 in an embodiment of the present invention. In this embodiment, the first unit 100 includes a first demodulator 131 and a first synchronization module 132 connected to the first connection part 110 side. Also, the second unit includes a second demodulator 231 and a second synchronization module 232 connected to the second connection part side. The wireless repeater 1 in this embodiment further includes synchronization signal acquisition parts 133, 233, a donor-side local signal switching part 134, and a service-side local signal switching part 234.

[0021] The first unit 100 includes a first demodulator 131 and a first synchronization module 132 connected to the first connection part 110 side. Also, the second unit includes a second demodulator 231 and a second synchronization module 232 connected to the second connection part side. Based on the demodulation result in the first demodulator 131, the synchronization signal acquisition unit 133 obtains a synchronization signal by switching the donor-side local signal by the donor-side local signal switching unit 134. Alternatively, based on the demodulation result in the second demodulator 231, the synchronization signal acquisition unit 233 obtains a synchronization signal by switching the service-side local signal by the service-side local signal switching unit 234.

[0022] FIG. 11 shows a configuration example of the wireless repeater 1 in an embodiment of the present invention. In this embodiment, the donor-side local signal switching unit 134 and the service-side local signal switching unit 234 further include a donor-side switching transceiver 135 and a service-side switching transceiver 235, respectively. When one of the donor-side local signal switching unit 134 and the service-side local signal switching unit 234 switches the local signal, a local signal switching signal is transmitted to the other via the donor-side switching transceiver 135 and the service-side switching transceiver 235, and the other of the donor-side local signal switching unit 134 and the service-side local signal switching unit 234 selects the frequency of the local signal.

[0023] In this way, in a unit different from the unit that performs the local signal switching control, the frequency information of the local signal of the unit that performs the switching control is received, and the frequency of the local signal is adjusted. The synchronization module obtains a synchronization signal by demodulating fIF1. Since only one synchronization module is required, it is small-sized and low-cost.

[0024] In an embodiment of the present invention, when there is an intermediate signal from which a synchronization signal cannot be obtained among the intermediate signals, the first synchronization module 132 and the second synchronization module 232 of the wireless repeater 1 perform switching control of the local signal and search for an intermediate frequency signal including the synchronization signal. That is, in this embodiment, when the synchronization signal can be obtained from both of the two systems, no special measures are required. When the synchronization signal can be obtained only from one side of the antennas 1 and 2, two local signals with frequencies fLO1 and fLO2 are switched, and the one from which the synchronization signal is obtained is set as fIF1.

[0025] FIG. 12 shows the frequency arrangement of the wireless repeater 1 in one embodiment of the present invention. In this embodiment, from the first intermediate signal to the Nth intermediate signal, each has a predetermined bandwidth D1. The band from the band of the first intermediate signal to the band of the Nth intermediate signal is separated from the adjacent band by a predetermined band D2.

[0026] In this embodiment, fRF = 28.0 GHz ± 200 MHz (400 MHz bandwidth), fIF1 = 3.0 GHz ± 200 MHz (400 MHz bandwidth), and fIF2 = 3.6 GHz ± 200 MHz (400 MHz bandwidth). The values of fLO1 and fLO2 are determined according to the specifications of the mixer. For example, the signals received from the donor antennas 101 and 102 and the signals received by the donor antennas 101 and 102 have different paths but the same frequency in the RF, that is, the high-frequency band where the antenna transmits and receives with the outside. On the other hand, in the IF, that is, the intermediate frequency band transmitted and received in the cable 300, the paths are the same and the frequencies are different.

[0027] FIG. 13 shows a configuration generalized to N systems where N is an integer of 2 or more. The local signal is switched so that the system from which the synchronization signal is obtained has the lowest frequency, and is also switched so that it has the lowest frequency for the band of the intermediate frequency band extracted by the synchronization module, whereby the same effect as in the case of two systems can be obtained even for N systems.

[0028] The present invention is not limited to the above embodiments, and it goes without saying that the present invention includes various embodiments without departing from the spirit of the present invention.

Explanation of Reference Numerals

[0029] 1 Wireless repeater 100 First unit 101, 102, 10N Donor antenna 110 First connection part 111, 112, 11N Donor - side frequency conversion part 120 Donor - side multiplexer 121 Donor - side combiner - splitter 122 Donor - side filter 131 First demodulator 132 First synchronization module 133 Synchronization signal acquisition part 134 Donor - side local signal switching part 135 Donor - side switching transceiver 200 Second unit 201, 202, 20N Service antenna 210 Second connection part 211, 212, 21N Service - side frequency conversion part 220 Service - side multiplexer 221 Service - side combiner - splitter 222 Service - side filter 231 Second demodulator 232 Second synchronization module 233 Synchronization signal acquisition part 234 Service - side local signal switching part 235 Service - side switching transceiver 300 Cable 401 Transmission front - end 402 Reception front - end 403 Multiplier 404 Band - pass filter BS Base station UE Terminal DU Donor unit SU Service unit D1 Predetermined bandwidth D2 Predetermined band segment

Claims

1. comprising a first unit, a second unit, and one cable connecting the first unit and the second unit, where the first unit includes, with N being an integer of 2 or more, N donor antennas from a first donor antenna to an Nth donor antenna that communicate with a base station, a first connection part connected to the cable, and N donor-side frequency conversion parts from a first donor-side frequency conversion part to an Nth donor-side frequency conversion part, the N donor-side frequency conversion parts from the first donor-side frequency conversion part to the Nth donor-side frequency conversion part each convert a signal of frequency fRF received by a corresponding donor antenna among the N donor antennas from the first donor antenna to the Nth donor antenna into an intermediate signal, which is an analog signal, from a first intermediate signal to an Nth intermediate signal using a respective local signal, the local signals and the intermediate signals have different frequencies for each of the donor-side frequency conversion parts, the second unit includes, N service antennas from a first service antenna to an Nth service antenna that communicate with a communication terminal, a second connection part connected to the cable, and N service-side frequency conversion parts from a first service-side frequency conversion part to an Nth service-side frequency conversion part, the N service-side frequency conversion parts from the first service-side frequency conversion part to the Nth service-side frequency conversion part each convert a signal of frequency fRF received by a corresponding service antenna among the N service antennas from the first service antenna to the Nth service antenna into an intermediate signal, which is an analog signal, from a first intermediate signal to an Nth intermediate signal using a respective local signal, the local signals and the intermediate signals have different frequencies for each of the service-side frequency conversion parts, The cable passes an intermediate signal which is an analog signal, A wireless repeater in which intermediate signals from the first intermediate signal to the Nth intermediate signal are superimposed and transmitted in the one cable.

2. A donor-side combining distributor connected between the donor antenna and the cable, and The wireless repeater according to claim 1, comprising a service-side combining distributor connected between the service antenna and the cable.

3. A donor-side filter connected between the donor antenna and the cable, and The wireless repeater according to claim 1, comprising a service-side filter connected between the service antenna and the cable.

4. A donor-side combining distributor connected between the donor antenna and the cable, and A service-side combining distributor connected between the service antenna and the cable, A donor-side filter connected between the donor antenna and the cable, and The wireless repeater according to claim 1, comprising a service-side filter connected between the service antenna and the cable.

5. The donor-side combining distributor and the donor-side filter are integrally configured as a donor-side multiplexer, The wireless repeater according to claim 4, wherein the service-side combining distributor and the service-side filter are integrally configured as a service-side multiplexer.

6. From the first intermediate signal to the Nth intermediate signal, each has a predetermined bandwidth, The wireless repeater according to claim 1, wherein the bandwidths from the first intermediate signal to the Nth intermediate signal are separated from adjacent bandwidths by a predetermined bandwidth.

7. Further comprising a synchronization signal acquisition unit, a donor-side local signal switching unit, and a service-side local signal switching unit. The first unit includes a first demodulator and a first synchronization module connected to the first connection unit side. The second unit includes a second demodulator and a second synchronization module connected to the second connection unit side. The synchronization signal acquisition unit is as follows: Based on the demodulation result in the first demodulator, the donor-side local signal switching unit switches the donor-side local signal to obtain a synchronization signal, or Based on the demodulation result in the second demodulator, the service-side local signal switching unit switches the service-side local signal to obtain a synchronization signal. The wireless repeater according to any one of claims 1 to 6.

8. The donor-side local signal switching unit and the service-side local signal switching unit each further include a donor-side switching transceiver and a service-side switching transceiver. When one of the donor-side local signal switching unit and the service-side local signal switching unit switches the local signal, a local signal switching signal is transmitted to the other via the donor-side switching transceiver and the service-side switching transceiver. The other of the donor-side local signal switching unit and the service-side local signal switching unit selects the frequency of the local signal. The wireless repeater according to claim 7.

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