Wireless terminal device, wireless communication system, and wireless communication method

Abstract

To improve the suppression effect of the interference between frequency channels.SOLUTION: A wireless terminal device sends and receives signals to / from a base station via a plurality of wireless relay devices. The wireless terminal device includes a modulation / demodulation section, an antenna, a beam control section that controls antenna beams directed at each of the plurality of wireless relay devices, and a frequency allocation section that allocates a frequency channel to be used by each of the plurality of wireless relay devices based on the difference in beam direction between the antenna beams directed at each of the plurality of wireless relay devices.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wireless terminal device, a wireless communication system, and a wireless communication method. [Background technology]

[0002] Conventionally, wireless communication receivers have used high-frequency (RF: Radio Frequency) band-pass filters (BPF: Band-Pass Filters) to suppress interference signals from outside the desired band, so that images (folded signals) of signals on frequency channels other than the main wave generated by down-conversion and out-of-band signals do not become interference signals when superimposed on the main wave, thereby avoiding spurious responses and nonlinear distortion in the receiver (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-277480 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional receivers, signals of frequency channels other than the main wave are attenuated by a BPF with a steep cutoff characteristic in the frequency band used. However, in recent wireless communication systems that use multiple frequency channels in higher frequency bands, it has been difficult to sufficiently attenuate signals of frequency channels other than the main wave using only a BPF.

[0005] The present invention has been made in consideration of the above circumstances, and its object is to improve the effect of suppressing interference between frequency channels. [Means for solving the problem]

[0006] One aspect of the present invention is a wireless terminal device that transmits and receives signals to and from a base station via a plurality of wireless relay devices, an RF unit provided corresponding to each of the plurality of wireless relay devices, which performs up-conversion and down-conversion between a radio signal in a first radio frequency band used in wireless transmission between the wireless terminal device and each wireless relay device and a baseband signal; and an RF unit provided corresponding to each of the plurality of wireless relay devices, which performs one-to-one wireless transmission of a radio signal in the first radio frequency band between each corresponding wireless relay device. a beam control unit for controlling an antenna beam directed to each of the plurality of wireless relay devices; and a beam control unit for controlling a beam direction of each of the plurality of wireless relay devices based on a beam direction difference between the antenna beams directed to each of the plurality of wireless relay devices. of the first radio frequency band The frequency channel is the RF units corresponding to the plurality of wireless relay devices, and a frequency allocation unit that allocates the frequency. One aspect of the present invention is A wireless terminal device that transmits and receives signals to and from a base station via a plurality of wireless relay devices includes: a beam control unit that controls an antenna beam directed to each of the plurality of wireless relay devices; and a frequency allocation unit that allocates a frequency channel to be used by each of the plurality of wireless relay devices based on a beam direction difference between the antenna beams directed to each of the plurality of wireless relay devices, The frequency allocation unit is a wireless terminal device that allocates frequency channels with greater frequency separation to combinations of wireless relay devices having smaller beam direction differences among the combinations of wireless relay devices in the plurality of wireless relay devices. One aspect of the present invention is A wireless terminal device that transmits and receives signals to and from a base station via a plurality of wireless relay devices includes: a beam control unit that controls an antenna beam directed to each of the plurality of wireless relay devices; and a frequency allocation unit that allocates a frequency channel to be used by each of the plurality of wireless relay devices based on a beam direction difference between the antenna beams directed to each of the plurality of wireless relay devices, The frequency allocation unit From the beam center direction of the antenna directivity characteristic Beam direction difference The direction is shifted by The wireless terminal device acquires antenna gain, and assigns frequency channels with greater frequency distances to combinations of wireless relay devices among the plurality of wireless relay devices that have larger antenna gains. One aspect of the present invention is A wireless terminal device that transmits and receives signals to and from a base station via a plurality of wireless relay devices includes: a beam control unit that controls an antenna beam directed to each of the plurality of wireless relay devices; and a frequency allocation unit that allocates a frequency channel to be used by each of the plurality of wireless relay devices based on a beam direction difference between the antenna beams directed to each of the plurality of wireless relay devices, The frequency allocation unit From the beam center direction of the antenna directivity characteristic Beam direction difference The direction is shifted by The wireless terminal device acquires antenna gain, and assigns frequency channels to be used by each of the plurality of wireless relay devices based on the antenna gain and the filter attenuation between frequency channels of a bandpass filter used for received signals of the wireless terminal device, so as to maximize the effect of suppressing interference between frequency channels.

[0007] One aspect of the present invention is a wireless communication system comprising any of the above-mentioned wireless terminal devices and a plurality of wireless relay devices, in which the wireless terminal device and each of the plurality of wireless relay devices communicate wirelessly using frequency channels assigned by the wireless terminal device to each of the plurality of wireless relay devices.

[0008] One aspect of the present invention is a wireless communication method in which a wireless terminal device transmits and receives signals to and from a base station via a plurality of wireless relay devices, the method comprising:an RF step in which the wireless terminal device is provided corresponding to each of the plurality of wireless relay devices, and performs up-conversion and down-conversion between a radio signal of a first radio frequency band used in wireless transmission between the wireless terminal device and each wireless relay device and a baseband signal; and an RF step in which the wireless terminal device is provided corresponding to each of the plurality of wireless relay devices, and performs one-to-one wireless transmission between the wireless terminal device and each corresponding wireless relay device using a radio signal of the first radio frequency band. a beam control step of controlling an antenna beam directed toward each of the wireless relay devices; The wireless terminal device Based on the beam direction difference between the antenna beams directed to each of the plurality of wireless relay devices, of the first radio frequency band The frequency channel is The RF steps corresponding to each of the plurality of wireless relay devices and a frequency allocation step of allocating a frequency. One aspect of the present invention is a wireless communication method in which a wireless terminal device transmits and receives signals to and from a base station via multiple wireless relay devices, the method including: a beam control step in which the wireless terminal device controls an antenna beam to be directed toward each of the multiple wireless relay devices; and a frequency allocation step in which the wireless terminal device assigns a frequency channel to be used by each of the multiple wireless relay devices based on a beam direction difference between the antenna beams directed toward each of the multiple wireless relay devices, wherein the frequency allocation step assigns frequency channels with greater frequency differences to combinations of wireless relay devices in the multiple wireless relay devices that have smaller beam direction differences. One aspect of the present invention is a wireless communication method in which a wireless terminal device transmits and receives signals to and from a base station via a plurality of wireless relay devices, the method including: a beam control step in which the wireless terminal device controls an antenna beam to be directed toward each of the plurality of wireless relay devices; and a frequency allocation step in which the wireless terminal device assigns a frequency channel to be used by each of the plurality of wireless relay devices based on a beam direction difference between the antenna beams directed toward each of the plurality of wireless relay devices, wherein the frequency allocation step obtains an antenna gain in a direction shifted by the beam direction difference from the beam center direction of the antenna directivity characteristic with respect to the beam center direction of the antenna directivity characteristic, and assigns frequency channels with greater frequency differences to combinations of wireless relay devices among the plurality of wireless relay devices that have greater antenna gain. One aspect of the present invention is a wireless communication method in which a wireless terminal device transmits and receives signals to and from a base station via multiple wireless relay devices, the wireless terminal device including: a beam control step in which the wireless terminal device controls an antenna beam to be directed toward each of the multiple wireless relay devices; and a frequency allocation step in which the wireless terminal device assigns a frequency channel to be used by each of the multiple wireless relay devices based on a beam direction difference between the antenna beams directed toward each of the multiple wireless relay devices, wherein the frequency allocation step obtains an antenna gain in a direction shifted by the beam direction difference from the beam center direction of the antenna directivity characteristic with respect to the beam center direction of the antenna directivity characteristic, and assigns a frequency channel to be used by each of the multiple wireless relay devices based on the antenna gain and the filter attenuation between frequency channels of a bandpass filter used for signals received by the wireless terminal device so as to maximize the effect of suppressing interference between frequency channels. [Effects of the Invention]

[0009] According to the present invention, it is possible to obtain an effect of improving the effect of suppressing interference between frequency channels. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a block diagram illustrating an example of the configuration of a wireless communication system according to an embodiment. [Figure 2] FIG. 10 is a diagram illustrating an example of orientation direction information according to an embodiment. [Figure 3] 1 is a flowchart showing an example of a procedure of a first example of a frequency channel allocation method according to an embodiment. [Figure 4] FIG. 1 is a diagram illustrating a frequency channel allocation method according to an embodiment. [Figure 5] FIG. 1 is a diagram illustrating a frequency channel allocation method according to an embodiment. [Figure 6] FIG. 1 is a diagram illustrating a frequency channel allocation method according to an embodiment. [Figure 7] 10 is a flowchart showing an example of a procedure of a second example of a frequency channel allocation method according to an embodiment. [Figure 8] FIG. 1 is a diagram illustrating a frequency channel allocation method according to an embodiment. [Figure 9] FIG. 1 is a diagram illustrating a frequency channel allocation method according to an embodiment. [Figure 10] FIG. 1 is a diagram illustrating a frequency channel allocation method according to an embodiment. [Figure 11] 10 is a flowchart illustrating an example of a procedure of a third example of a frequency channel allocation method according to an embodiment. [Figure 12] FIG. 1 is a diagram illustrating a frequency channel allocation method according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a block diagram showing an example of the configuration of a wireless communication system according to an embodiment. In the wireless communication system 1 shown in Fig. 1, the radio frequency used on the base station side differs from the radio frequency used on the terminal side, with a wireless relay device (repeater) 200 as the boundary. In the example of Fig. 1, the radio frequency used on the base station side is in the millimeter wave band. On the other hand, the radio frequency used on the terminal side is a frequency (high frequency band) higher than the millimeter wave band. The high frequency band is, for example, the terahertz band.

[0012] In the wireless communication system 1, a wireless terminal device (terminal) UE transmits and receives signals to and from a base station BS via a plurality of repeaters 200. In the example of Fig. 1, the terminal UE transmits and receives signals to and from a base station BS via four repeaters (#1, #2, #3, #4) 200. Note that the number of repeaters 200 is not limited to four.

[0013] Furthermore, the terminal UE may simultaneously transmit and receive signals to and from the base station BS via multiple repeaters 200, or may transmit and receive signals to and from the base station BS via multiple repeaters 200 at different times for each of the multiple repeaters 200.

[0014] The base station BS includes an antenna (base station antenna) that transmits and receives electromagnetic waves (carrier waves) that transmit signals to and from the terminal UE. In the example of Fig. 1, the carrier waves are millimeter waves. The repeater 200 transmits and receives the carrier waves by directing its antenna beam toward the base station antenna.

[0015] 1 shows only one base station BS, but when MIMO using spatial multiplexing is applied, multiple base stations BS exist, and the terminal UE transmits and receives signals to and from the multiple base stations BS via multiple repeaters 200. For example, when the millimeter wave band is the frequency band used, the MIMO method using spatial multiplexing can be applied.

[0016] 1 illustrates a base station BS, an antenna site equipped with a base station antenna provided separately from the base station BS may be used instead. In this case, the repeater 200 transmits and receives carrier waves by directing its own antenna beam toward the antenna site.

[0017] The duplexing method of the wireless communication system 1 may be a TDD (Time Division Duplex) method or an FDD (Frequency Division Duplex) method.

[0018] 1, the terminal UE includes a modulation / demodulation unit 101, RF units 102, 103, 104, and 105, beam control units 106, 107, 108, and 109, a frequency allocation unit 110, and antennas 111, 112, 113, and 114. The repeater 200 includes a terminal-side antenna 201, a frequency conversion type wireless repeater unit 202, and a base station-side antenna 203.

[0019] In the terminal UE, in order to communicate with the base station BS via each repeater (#1, #2, #3, #4) 200, a modulation / demodulation unit 101 outputs a modulated signal to be transmitted as an uplink signal (uplink signal) from the terminal UE to the base station BS to RF units 102, 103, 104, 105 corresponding to each repeater (#1, #2, #3, #4) 200. Furthermore, with regard to a downlink signal (downlink signal) from the base station BS to the terminal UE, the modulation / demodulation unit 101 inputs a downlink signal received from the base station BS via each repeater (#1, #2, #3, #4) 200 from the RF units 102, 103, 104, 105 corresponding to each repeater (#1, #2, #3, #4) 200.

[0020] The RF units 102, 103, 104, and 105 perform up-conversion and down-conversion between the baseband signal input from the modem unit 101 and a high-frequency signal in a high frequency band used in wireless transmission between the terminal UE and each repeater (#1, #2, #3, #4) 200. When the TDD system is used as the duplex system, the RF units 102, 103, 104, and 105 switch between a transmission circuit for uplink signals and a reception circuit for downlink signals.

[0021] Beam control units 106, 107, 108, and 109 control the antenna beams to be directed toward the four repeaters (#1, #2, #3, and #4) 200. To perform one-to-one wireless transmission in the high frequency band with the corresponding repeaters (#1, #2, #3, and #4) 200, the beam control units 106, 107, 108, and 109 direct antenna beams BM1, BM2, BM3, and BM4 of the antennas 111, 112, 113, and 114 toward the corresponding repeaters (#1, #2, #3, and #4) 200.

[0022] The frequency allocation unit 110 allocates frequency channels to be used by each of the four repeaters (#1, #2, #3, #4) 200 based on the beam direction difference between the antenna beams directed toward each of the four repeaters (#1, #2, #3, #4) 200. The frequency allocation unit 110 acquires directivity information “φ1, θ1”, “φ2, θ2”, “φ3, θ3”, and “φ4, θ4” of the antenna beams BM1, BM2, BM3, and BM4 of the antennas 111, 112, 113, and 114 from the beam control units 106, 107, 108, and 109.

[0023] 2 is a diagram illustrating an example of directivity direction information according to this embodiment. As shown in FIG. 2 as an example, the directivity direction information "φ1, θ1," "φ2, θ2," "φ3, θ3," and "φ4, θ4" may be expressed as a counterclockwise angle in the horizontal direction, with the front direction of the antennas 111, 112, 113, and 114 being 0°, and θ as a vertical angle, with the direction directly above the antennas 111, 112, 113, and 114 being 0°. The front direction and the direction directly above the antennas 111, 112, 113, and 114 may be the same for all of the antennas 111, 112, 113, and 114, or may be different for each of the antennas 111, 112, 113, and 114.

[0024] 2, and the front and upward directions of the antennas are the same for all of the antennas 111, 112, 113, and 114. If the front and upward directions of the antennas are different for each of the antennas 111, 112, 113, and 114, the directivity information "φ1, θ1", "φ2, θ2", "φ3, θ3", and "φ4, θ4" may use φ and θ converted based on the front and upward directions of any of the antennas 111, 112, 113, and 114.

[0025] The frequency allocation unit 110 determines a frequency channel in the high frequency band to be used between the terminal UE and each of the repeaters (#1, #2, #3, #4) 200. Based on the determined frequency channel, the frequency allocation unit 110 sets frequencies for upconversion and downconversion between the terminal UE and each of the repeaters (#1, #2, #3, #4) 200 and the RF units 102, 103, 104, 105.

[0026] The terminal UE notifies each repeater (#1, #2, #3, #4) 200 of the frequency channel determined by the frequency allocation unit 110. In each repeater (#1, #2, #3, #4) 200, the frequency conversion type radio repeater unit 202 sets the frequency channel notified from the terminal UE as the frequency channel to be used in the high frequency band.

[0027] The frequency channel may be notified from the terminal UE to each of the repeaters (#1, #2, #3, #4) 200 by any method, and the notification method is not limited thereto. For example, in the wireless communication system 1, frequency channel information indicating the frequency channel may be wirelessly transmitted from the terminal UE to each of the repeaters (#1, #2, #3, #4) 200 by utilizing a guard band of the band of the wireless transmission channel of the uplink signal. For example, the frequency channel information may be wirelessly transmitted from the terminal UE to each of the repeaters (#1, #2, #3, #4) 200 by short-range wireless communication between the terminal UE and each of the repeaters (#1, #2, #3, #4) 200. For example, "Bluetooth (registered trademark)" or "Wi-Fi (registered trademark)" may be used as the short-range wireless communication method.

[0028] In the repeater (#1, #2, #3, #4) 200, the frequency conversion type wireless repeater unit 202 converts the uplink signal in the high frequency band received by the terminal side antenna 201 to the operating frequency in the millimeter wave band, and transmits it to the base station BS from the base station side antenna 203. In addition, the frequency conversion type wireless repeater unit 202 converts the downlink signal in the millimeter wave band received by the base station side antenna 203 to a frequency channel set in the high frequency band, and transmits it from the terminal side antenna 201 to the terminal UE.

[0029] Next, a frequency channel allocation method according to this embodiment will be described by way of example.

[0030] The frequency allocation unit 110 of the terminal UE allocates frequency channels to be used between the terminal UE and each of the repeaters (#1, #2, #3, #4) 200.

[0031] In the following explanation, for convenience of explanation, the beam directions of the antenna beams BM1, BM2, BM3, and BM4 of the antennas 111, 112, 113, and 114 will be explained as two-dimensional, but the same can be applied even if the beam directions are three-dimensional using φ and θ by using the relative directional difference between each beam direction. Furthermore, the four repeaters (#1, #2, #3, and #4) 200 will sometimes be referred to as repeater #1, repeater #2, repeater #3, and repeater #4, respectively.

[0032] (Example 1 of frequency channel allocation method) A first example of the frequency channel allocation method according to this embodiment will be described with reference to Figures 3 to 6. Figure 3 is a flowchart showing an example of the procedure of the first example of the frequency channel allocation method according to this embodiment.

[0033] In example 1 of the frequency channel allocation method, the frequency allocation unit 110 allocates frequency channels with greater frequency separation to combinations of repeaters 200 among four repeaters (#1, #2, #3, #4) 200 with smaller beam direction differences.

[0034] (Step S101) In the terminal UE, the frequency allocation unit 110 acquires beam directions "φn, n=1, 2, 3, 4" of antenna beams BM1, BM2, BM3, BM4 to each repeater (#1, #2, #3, #4) 200 from the beam control units 106, 107, 108, 109. Here, as an example for explanation, as shown in Fig. 4, the beam direction φ1 for repeater #1 is "0°", the beam direction φ2 for repeater #2 is "-30°", the beam direction φ3 for repeater #3 is "-50°", and the beam direction φ4 for repeater #4 is "60°".

[0035] (Step S102) The frequency allocation unit 110 calculates the beam direction difference between the repeaters 200 for each combination of four repeaters (#1, #2, #3, #4) 200. As an example for illustrative purposes, as shown in FIG. 4, the beam direction difference between repeater #1 and repeater #2 is "Δφ1,2 = φ1 - φ2 = 30°," the beam direction difference between repeater #2 and repeater #3 is "Δφ2,3 = φ2 - φ3 = 20°," the beam direction difference between repeater #1 and repeater #3 is "Δφ1,3 = φ1 - φ2 = 50°," the beam direction difference between repeater #4 and repeater #1 is "Δφ4,1 = φ4 - φ1 = 60°," and so on. FIG. 5 shows the beam direction differences between the repeaters 200.

[0036] (Step S103) The frequency allocation unit 110 sorts the beam direction differences in ascending order. Here, as an example for illustrative purposes, the sorting results are Δφ2,3 "20°", Δφ1,2 "30°", Δφ1,3 "50°", Δφ4,1 "60°", ... The frequency allocation unit 110 allocates frequency channels with greater frequency distances in the order of the sorting results. As a result, the smaller the beam direction difference between the combinations of repeaters 200, the more frequency channels with greater frequency distances are allocated to them.

[0037] Here, as an example for illustrative purposes, the frequency channels in the high frequency band of the wireless communication system 1 are the four frequency channels "#Fa," "#Fb," "#Fc," and "#Fd" shown in FIG. 6. The frequency allocation unit 110 allocates the frequency channels "#Fa" and "#Fd" at both ends on the frequency axis to "(1) Repeater #2, Repeater #3," which has the smallest beam direction difference. For example, the frequency allocation unit 110 allocates frequency channel "#Fa" to repeater #2 and frequency channel "#Fd" to repeater #3. Next, the frequency allocation unit 110 allocates the frequency channel "#Fc," which is the farthest on the frequency axis from the frequency channel "#Fa" of repeater #2, out of the unallocated frequency channels "#Fb" and "#Fc," to repeater #1, which has the next smallest beam direction difference and to which no frequency channel is allocated. Next, the frequency allocation unit 110 skips the allocation process for "(3) Repeater #1, Repeater #3," which has the next smallest beam direction difference, because both have already been assigned frequency channels. Next, the frequency allocation unit 110 assigns the remaining frequency channel "#Fb" to repeater #4, which has the next smallest beam direction difference, among "(4) Repeater #1, Repeater #4," which has not yet been assigned a frequency channel.

[0038] (Example 2 of frequency channel allocation method) A second example of the frequency channel allocation method according to this embodiment will be described with reference to Figures 7 to 10. Figure 7 is a flowchart showing an example of the procedure of the second example of the frequency channel allocation method according to this embodiment.

[0039] In example 2 of the frequency channel allocation method, the frequency allocation unit 110 obtains the antenna gain corresponding to the beam direction difference, and assigns frequency channels with greater frequency distances to combinations of repeaters 200 among the four repeaters (#1, #2, #3, #4) 200 that have larger antenna gains.

[0040] Steps S201 and S202 in the procedure of Fig. 7 are the same as steps S101 and S102 in Fig. 3. Here, as an example for the purpose of explanation, steps S201 and S202 are used to determine the beam direction differences between the repeaters 200 shown in Fig. 5.

[0041] (Step S203) The frequency allocation unit 110 acquires the antenna gain in a direction shifted by the beam direction difference from the beam center direction of the antenna directivity characteristics. Here, as an example for explanation, the antenna directivity characteristics are shown in FIG. 8. Also, an example (excerpt) of antenna gain data corresponding to the antenna directivity characteristics of FIG. 8 is shown in FIG. 10. The terminal UE holds the antenna gain data exemplified in FIG. 10 in advance. For example, the frequency allocation unit 110 acquires the antenna gain "-0.87 [dB]" corresponding to the beam direction difference of "20°" between "(1) repeater #2 and repeater #3" from the antenna gain data of FIG. 10. The results of each antenna gain acquired in a similar manner are shown in FIG. 9. The antenna gain data may be a list of antenna gains as shown in FIG. 10, or may be a function for deriving the antenna gain.

[0042] (Step S204) The frequency allocation unit 110 sorts the results in descending order of antenna gain. Here, as an example for illustrative purposes, the sorting results are "(1) Repeater #2, Repeater #3: -0.87 [dB]", "(2) Repeater #1, Repeater #2: -5 [dB]", "(3) Repeater #1, Repeater #3: -12 [dB]", "(4) Repeater #1, Repeater #4: -15 [dB]", .... The frequency allocation unit 110 allocates frequency channels with greater frequency distances in the order of the sorting results. As a result, the greater the antenna gain of a combination of repeaters 200, the more frequency channels with greater frequency distances are allocated to them.

[0043] Here, as an example for illustrative purposes, the frequency channels in the high frequency band of the wireless communication system 1 are the four frequency channels "#Fa," "#Fb," "#Fc," and "#Fd" shown in FIG. 6. The frequency allocation unit 110 allocates the frequency channels "#Fa" and "#Fd" at both ends on the frequency axis to "(1) Repeater #2, Repeater #3" which has the largest antenna gain. For example, the frequency allocation unit 110 allocates frequency channel "#Fa" to repeater #2 and frequency channel "#Fd" to repeater #3. Next, the frequency allocation unit 110 allocates the frequency channel "#Fc" which is the furthest on the frequency axis from the frequency channel "#Fa" of repeater #2 out of the unallocated frequency channels "#Fb" and "#Fc" to repeater #1 which has the next largest antenna gain and to which no frequency channel is allocated. Next, the frequency allocation unit 110 skips the allocation process for "(3) Repeater #1, Repeater #3," which has the next largest antenna gain, because both have already been assigned a frequency channel. Next, the frequency allocation unit 110 allocates the remaining frequency channel "#Fb" to Repeater #4, which has not yet been assigned a frequency channel, among "(4) Repeater #1, Repeater #4," which has the next largest antenna gain.

[0044] (Example 3 of frequency channel allocation method) A third example of the frequency channel allocation method according to this embodiment will be described with reference to Figures 11 and 12. Figure 11 is a flowchart showing an example of the procedure of the third example of the frequency channel allocation method according to this embodiment.

[0045] In the third example of the frequency channel allocation method, the frequency allocation unit 110 acquires the antenna gain corresponding to the beam direction difference, and allocates the frequency channel to be used by each of the four repeaters (#1, #2, #3, #4) 200 based on the antenna gain and the filter attenuation between the frequency channels of the bandpass filters used for the signals received by the terminal UE so as to maximize the effect of suppressing interference between the frequency channels. Data on the filter attenuation between the frequency channels of the bandpass filters used for the signals received by the terminal UE (filter attenuation data) is stored in advance in the terminal UE.

[0046] In the procedure of Fig. 11, steps S301 and S302 are the same as steps S101 and S102 in Fig. 3 described above, and step S303 is the same as step S203 in Fig. 7 described above. Here, as an example for the purpose of explanation, the antenna gains shown in Fig. 9 are obtained by steps S301, S302, and S303.

[0047] (Step S304) The frequency allocation unit 110 finds the combination that minimizes the sum of the antenna gain and the filter attenuation from among all combinations of frequency channel allocations for the four repeaters (#1, #2, #3, #4) 200. Here, the antenna gain is larger as the gain is higher and smaller as the gain is lower. Also, the filter attenuation is smaller as the attenuation is higher and larger as the attenuation is lower.

[0048] Here, as an example for the purpose of explanation, the frequency channels in the high frequency band of the wireless communication system 1 are the four frequency channels "#Fa", "#Fb", "#Fc", and "#Fd" shown in FIG.

[0049] Specifically, frequency allocation unit 110 finds "freq(i) {i=1,2,3,4}" that minimizes the value of the following equation (1): freq(i) is the frequency channel to be allocated to repeater #i from among frequency channels "#Fa," "#Fb," "#Fc," and "#Fd." Σ( Gant(i,j)+Gfilt(freq(i)-freq(j))) {i=1,2,3,4, j=1,2,3,4, i≠j} (1)

[0050] In equation (1), i, j are repeater numbers (n for repeater #n, n = 1, 2, 3, 4). Gant(i, j) is the antenna gain for repeater #i and repeater #j. Gfilt(freq(i)-freq(j)) is the filter attenuation between the frequency channel assigned to repeater #i and the frequency channel assigned to repeater #j. An example of filter attenuation data is shown in Figure 12. The filter attenuation data is stored in advance in the terminal UE. The filter attenuation data may be a list of filter attenuation as exemplified in Figure 12, or may be a function that derives the filter attenuation.

[0051] As described above, according to this embodiment, a frequency channel to be used by each of the plurality of repeaters 200 is assigned based on the beam direction difference between the antenna beams directed to each of the plurality of repeaters 200. This makes it possible to improve the effect of suppressing interference between adjacent frequency channels even without a BPF having a sharp cutoff characteristic in the frequency band being used.

[0052] Furthermore, since the frequency channel is assigned by the terminal UE, the repeater 200 does not need to perform frequency channel assignment processing, which contributes to reducing the size and weight of the repeater 200 that uses a high frequency band between the terminal UE and the repeater 200.

[0053] This will enable improvements in the overall service quality of wireless communication systems, for example, and contribute to Goal 9 of the United Nations' Sustainable Development Goals (SDGs), which is to "Build resilient infrastructure, promote sustainable industrialization and foster innovation."

[0054] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present invention.

[0055] In addition, a computer program for realizing the functions of each of the above-described devices may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read and executed by a computer system. Note that the "computer system" here may also include hardware such as an OS and peripheral devices. In addition, "computer-readable recording medium" refers to writable non-volatile memory such as a flexible disk, optical magnetic disk, ROM, or flash memory, portable media such as a DVD (Digital Versatile Disc), or a storage device such as a hard disk built into a computer system.

[0056] Furthermore, the term "computer-readable recording medium" also includes those that retain a program for a certain period of time, such as volatile memory (e.g., DRAM (Dynamic Random Access Memory)) within a computer system that serves as a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by transmission waves in the transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has the function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may also be a program for implementing some of the functions described above, or may be a so-called differential file (differential program) that can implement the functions described above in combination with a program already stored in the computer system. [Explanation of symbols]

[0057] 1...wireless communication system, UE...wireless terminal device, 101...modulation / demodulation unit, 102, 103, 104, 105...RF unit, 106, 107, 108, 109...beam control unit, 110...frequency allocation unit, 111, 112, 113, 114...antenna, 200...wireless relay device, 201...terminal side antenna, 202...frequency conversion type wireless relay unit, 203...base station side antenna, BS...base station

Claims

1. In a wireless terminal device that transmits and receives signals to and from a base station via a plurality of wireless relay devices, an RF unit provided corresponding to each of the plurality of radio relay devices, and performing up-conversion and down-conversion between a radio signal in a first radio frequency band used in radio transmission between the radio terminal device and each of the radio relay devices and a baseband signal; a beam control unit provided corresponding to each of the plurality of wireless relay devices, the beam control unit controlling an antenna beam directed toward each of the corresponding wireless relay devices in order to perform one-to-one wireless transmission of a wireless signal in the first wireless frequency band between the wireless relay devices; a frequency allocation unit that allocates frequency channels in the first radio frequency band to be used by each of the plurality of wireless relay devices to the RF units corresponding to the plurality of wireless relay devices, based on a beam direction difference between antenna beams directed toward the plurality of wireless relay devices; A wireless terminal device comprising:

2. A wireless terminal device that transmits and receives signals to and from a base station via multiple wireless relay devices, a beam control unit that controls an antenna beam directed toward each of the plurality of radio relay devices; a frequency allocation unit that allocates frequency channels to be used by each of the plurality of wireless relay devices based on a beam direction difference between antenna beams directed toward each of the plurality of wireless relay devices; Equipped with the frequency allocation unit allocates frequency channels with greater frequency separation to combinations of wireless relay devices having smaller beam direction differences among the combinations of wireless relay devices in the plurality of wireless relay devices; Wireless terminal device.

3. A wireless terminal device that transmits and receives signals to and from a base station via multiple wireless relay devices, a beam control unit that controls an antenna beam directed toward each of the plurality of radio relay devices; a frequency allocation unit that allocates frequency channels to be used by each of the plurality of wireless relay devices based on a beam direction difference between antenna beams directed toward each of the plurality of wireless relay devices; Equipped with the frequency allocation unit acquires antenna gains in directions shifted by a beam direction difference from the beam center direction of the antenna directivity characteristics with respect to a beam center direction of the antenna directivity characteristics, and allocates frequency channels with greater frequencies to combinations of wireless relay devices among the plurality of wireless relay devices that have larger antenna gains. Wireless terminal device.

4. A wireless terminal device that transmits and receives signals to and from a base station via multiple wireless relay devices, a beam control unit that controls an antenna beam directed toward each of the plurality of radio relay devices; a frequency allocation unit that allocates frequency channels to be used by each of the plurality of wireless relay devices based on a beam direction difference between antenna beams directed toward each of the plurality of wireless relay devices; Equipped with The frequency allocation unit Acquire an antenna gain in a direction shifted by a beam direction difference from the beam center direction of the antenna directivity characteristic with respect to the beam center direction of the antenna directivity characteristic; assigning frequency channels to be used by each of the plurality of wireless relay devices based on an antenna gain and a filter attenuation between frequency channels of a bandpass filter used for a signal received by the wireless terminal device so as to maximize an effect of suppressing interference between frequency channels; Wireless terminal device.

5. A wireless terminal device according to any one of claims 1 to 4; a plurality of wireless relay devices; the wireless terminal device performs wireless communication with each of the plurality of wireless relay devices using a frequency channel assigned by the wireless terminal device to each of the plurality of wireless relay devices; Wireless communication system.

6. A wireless communication method in which a wireless terminal device transmits and receives signals to and from a base station via a plurality of wireless relay devices, comprising: an RF step in which the wireless terminal device is provided corresponding to each of the plurality of wireless relay devices, and up-converts and down-converts a radio signal in a first radio frequency band used in wireless transmission between the wireless terminal device and each of the wireless relay devices and a baseband signal; a beam control step in which the wireless terminal device is provided corresponding to each of the plurality of wireless relay devices, and controls an antenna beam directed toward each of the corresponding wireless relay devices in order to perform one-to-one wireless transmission of a wireless signal in the first wireless frequency band between the wireless terminal device and each of the corresponding wireless relay devices; a frequency allocation step in which the wireless terminal device allocates frequency channels of the first radio frequency band to be used by each of the plurality of wireless relay devices to the RF channels corresponding to each of the plurality of wireless relay devices based on beam direction differences between antenna beams directed toward each of the plurality of wireless relay devices; A wireless communication method comprising:

7. A wireless communication method in which a wireless terminal device transmits and receives signals to and from a base station via multiple wireless relay devices, comprising: a beam control step in which the wireless terminal device controls an antenna beam directed toward each of the plurality of wireless relay devices; a frequency allocation step in which the wireless terminal device allocates frequency channels to be used by each of the plurality of wireless relay devices based on a beam direction difference between antenna beams directed toward each of the plurality of wireless relay devices; Including, the frequency allocating step allocates frequency channels with greater frequency separation to combinations of wireless relay devices having smaller beam direction differences among the plurality of wireless relay devices; Wireless communication method.

8. A wireless communication method in which a wireless terminal device transmits and receives signals to and from a base station via multiple wireless relay devices, comprising: a beam control step in which the wireless terminal device controls an antenna beam directed toward each of the plurality of wireless relay devices; a frequency allocation step in which the wireless terminal device allocates frequency channels to be used by each of the plurality of wireless relay devices based on a beam direction difference between antenna beams directed toward each of the plurality of wireless relay devices; Including, the frequency allocation step acquires antenna gains in directions shifted by a beam direction difference from the beam center direction of the antenna directivity characteristics with respect to a beam center direction of the antenna directivity characteristics, and allocates frequency channels with greater frequencies to combinations of wireless relay devices among the plurality of wireless relay devices that have larger antenna gains. Wireless communication method.

9. A wireless communication method in which a wireless terminal device transmits and receives signals to and from a base station via multiple wireless relay devices, comprising: a beam control step in which the wireless terminal device controls an antenna beam directed toward each of the plurality of wireless relay devices; a frequency allocation step in which the wireless terminal device allocates frequency channels to be used by each of the plurality of wireless relay devices based on a beam direction difference between antenna beams directed toward each of the plurality of wireless relay devices; Including, The frequency allocation step Acquire an antenna gain in a direction shifted by a beam direction difference from the beam center direction of the antenna directivity characteristic with respect to the beam center direction of the antenna directivity characteristic; assigning frequency channels to be used by each of the plurality of wireless relay devices based on an antenna gain and a filter attenuation between frequency channels of a bandpass filter used for a signal received by the wireless terminal device so as to maximize an effect of suppressing interference between frequency channels; Wireless communication method.

Images