Information processing device, information processing method, program, and wireless communication system

Abstract

An information processing device (10) comprises: an acquisition unit (11) for acquiring information pertaining to wireless communication for a backhaul link between a first base station (20A) and a second base station (20B), and information pertaining to wireless communication for an access link between the second base station and a user terminal; a control unit (12) for determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link on the basis of the information acquired by the acquisition unit; and a transmission unit (13) for transmitting information indicating the first wireless communication method determined by the control unit to the first base station and / or the second base station, and transmitting information indicating the second wireless communication method to the second base station and / or the user terminal.

Description

[Technical field]

[0001] The present disclosure relates to an information processing device, an information processing method, a program, and a wireless communication system. [Background technology]

[0002] With the rapid spread of Long Term Evolution (LTE) and LTE-Advanced, it is becoming possible to provide full-scale mobile broadband services. In order to handle the rapidly increasing traffic in cellular networks, the fifth generation mobile communication system (5G) requires even higher speed and capacity than LTE, as well as improved frequency utilization efficiency. In addition to an ultra-high-speed, high-capacity wireless access network that provides gigabit-class services to user equipment (UE), even higher speed and capacity is required for the backhaul between base stations and the Serving-Gateway (S-GW) of the Evolved Packet Core (EPC) network. Backhaul links consist of E1 / T1 dedicated lines, optical fiber networks, microwave wireless backhaul, etc. Wireless backhaul has the advantage of lower network costs compared to wired backhaul.

[0003] FIG. 1 shows a configuration example of HetNet (one example of a "wireless communication system 1"). In the example of FIG. 1, HetNet1 includes a macrocell base station (concentration base station) 20A, a small cell base station (relay base station) 20B, and a small cell base station 20C. In the following, when there is no need to distinguish between base stations such as the macrocell base station 20A, the small cell base station 20B, and the small cell base station 20C, they are also simply referred to as "base stations 20". The coverage area of ​​the macrocell base station 20A is referred to as a macrocell. Also, the coverage areas of the small cell base station 20B and the small cell base station 20C are referred to as small cells. A heterogeneous network (HetNet) that overlays small cells that efficiently accommodate non-uniform traffic in a macrocell can accommodate non-uniform traffic in a macrocell in the network with high efficiency while ensuring a wide coverage area.

[0004] In the example of FIG. 1, HetNet1 includes user terminals 30A, 30B, and 30C (hereinafter, when there is no need to distinguish between them, they are also simply referred to as "user terminals 30"). The number of base stations 20 and user terminals 30 is not limited to the example of FIG. 1. The macrocell base station 20A and the small cell base station 20B are connected by a wireless backhaul N1. The small cell base station 20B and the small cell base station 20C are connected by a wireless backhaul N2. The macrocell base station 20A is connected to a higher-level station (core network) 40 so as to be able to communicate with the higher-level station.

[0005] The macro cell guarantees a coverage area for each user terminal 30 within the cell. In areas of the macro cell where traffic is high, small cells are deployed to accommodate the traffic. Methods have been proposed in which the macro cell and small cell use the same frequency spectrum and methods in which different frequency spectrums are used. When different frequency spectrums are used for the macro cell and small cell, different frequency spectrums are assigned so that the frequency spectrums of the macro cell and small cell do not interfere with each other.

[0006] In practical HetNet, a method is adopted in which different frequency spectra are used for macro cells and small cells. On the other hand, a method in which the same frequency spectrum is used for macro cells and small cells is effective from the viewpoint of frequency efficiency, but it is required to avoid interference between macro cells and small cells or between adjacent small cells. Since the transmission power of a macro cell is higher than that of a small cell, in a cell search in which user terminals 30A to C search for a cell site (base station) to which a wireless link is to be connected, the received power from the macro cell base station 20A is higher than the received power from the cell site of a nearby small cell. Therefore, Cell Range Expansion (CRE) is adopted in which an offset is applied to the reference signal received power (RSRP: Reference Signal Received Power) from the nearby small cell base station 20B or 20C measured by the user terminals 30A to C, and the small cell base station is searched for and a wireless link is connected. Also, a method is adopted in which a subframe called an Almost Blank Subframe (ABS) that transmits only a synchronization signal, control information, and a cell-specific reference signal (CRS) is provided in the macrocell base station 20A, thereby reducing interference with a transmission signal from a small cell.

[0007] In HetNet, in order to perform efficient resource control including avoidance of inter-cell interference between a macrocell and a small cell, and between small cells in a macrocell, it is effective to install a macrocell base station 20A at the macrocell site and a remote radio equipment (RRE: Remote Radio Equipment, or RRH: Remote Radio Head) at the small cell site. The macrocell base station 20A and the RRE are connected by high-speed optical fiber or a wireless link, with the transmitted signal being a modulated baseband signal, and the received signal being a pre-demodulated baseband signal. Since the physical layer and upper layers of the small cell are processed by the macrocell base station 20A, unified resource allocation including the small cell in the macrocell base station 20A is realized. Also, from the viewpoint of installation cost and operation cost, it is effective to realize the connection between the macrocell base station 20A and the RRE by a wireless link.

[0008] 3GPP (registered trademark) (Third Generation Partnership Project) has formulated the standard of Integrated Access and Backhaul (IAB), which uses the same frequency spectrum for the 5G NR (New Radio) radio interface for the backhaul link in addition to the access link. FIG. 2 shows an example of the layer configuration and interface of the IAB. The macrocell base station 20A of the IAB donor and the small cell base stations 20B and 20C of the IAB node are connected by a backhaul link. The base station of the IAB node and the user terminal 30 are connected by an access link. The IAB donor base station is composed of a Central Unit (CU). The IAB node is composed of a Distributed Unit (DU). Here, the Adaptation shown in FIG. 2 may also be called Backhaul Adaptation Protocol (BAP).

[0009] FIG. 3 shows the relationship between each node and link in the IAB. With the central IAB node as the center, the higher IAB parent node is the IAB donor, and the lower IAB node is the IAB child node. The central IAB node connects the user terminal 30 with an access link. DL BH indicates a downlink backhaul link, and UL BH indicates an uplink backhaul link. The IAB node has a UL access function and a backhaul link function for the child IAB node. Resource allocation for downlink transmission of the IAB node, that is, scheduling, is performed at the IAB node. For downlink transmission, the backhaul link from the IAB node to the child IAB node and the access link from the IAB node to the user terminal 30 are used.

[0010] On the other hand, the scheduling of resource allocation for the IAB node's uplink transmission (backhaul link from the IAB node to the parent IAB node or IAB donor) is performed by the parent IAB node or IAB donor. In 3GPP's IAB, half duplex (HD) using time division multiplexing (TDM), frequency division multiplexing (FDM), and space division multiplexing (SDM) is supported for multiplexing the access link and backhaul link. In other words, full duplex (FD), in which an IAB node transmits and receives in the same resource block in the same time slot, is not applicable.

[0011] Although optical fiber is the mainstream for backhaul links, microwave wireless backhaul is more advantageous than wired backhaul in terms of installation and operation costs. 3GPP has formulated the Integrated Access and Backhaul (IAB) radio interface, which is an extension of the NR radio interface to the backhaul link. The IAB radio interface can realize access links and backhaul links in the same frequency spectrum, so when applied to HetNet, it can provide efficient services. However, the IAB is a radio interface that is an extension of the Release 15 radio interface for access links to the backhaul link between base stations. In the case of multi-antenna (multi-layer) transmission, Orthogonal frequency division multiple access (OFDMA) is adopted for the uplink and downlink. In addition, the modulation method adopted is Quadrature Amplitude Modulation (QAM) with up to 256 values ​​in rectangular signal space arrangement. [Prior art documents] [Non-patent literature]

[0012] [Non-Patent Document 1] 3GPP TR 38.874 Study on Integrated Access and Backhaul, V16.0.0 (2018-12). [Non-Patent Document 2] M. Polese, M. Giordani, T. Zugno, A. Roy, S. Goyal, D. Castor; and M. Zorzi, “Integrated Access and Backhaul in 5G mmWave Networks: Potential and Challenges,” IEEE Communications Magazine, vol.58, no.3, pp.62-68, March 2020. [Non-Patent Document 3] C.Madapatha, B.Makki, C.Fang, O.Teyeb, E.Dahlman, M.-S.Alouini, and T.Svensson, “On Integrated Access and Backhaul Networks: Current Status and Potentials,” IEEE Open Journal of the Communications Society, Vol.1, pp.1374-1389, Sept.2020. [Non-Patent Document 4] M. Schnell and I. De Broeck, “Interleaved FDMA: equalization and coded performance in mobile radio applications,” 1999 IEEE International Conference on Communications, 1999. [Non-Patent Document 5] N. Maeda, Y. Kishiyama, H. Atarashi, and M. Sawahashi, “Variable Spreading Factor-OFCDM with Two Dimensional Spreading that Prioritizes Time Domain Spreading for Forward Link Broadband Wireless Access,” IEICE Trans. Commun., vol.E88-B, no.2, pp.487-498, Feb.2005. [Non-Patent Document 6] JEMazo, “Faster-than-nyquist signaling,” The Bell System Technical Journal, vol.54, no.8, 1975. Summary of the Invention [Problem to be solved by the invention]

[0013] The IAB radio interface is an extension of the NR radio interface for access links to the backhaul link, and is not optimized for backhaul links, which are likely to be in a line-of-sight (LOS) environment.

[0014] The present disclosure has been made in consideration of the above points, and has an object to provide a technique that enables wireless communication to be performed more appropriately. [Means for solving the problem]

[0015] In a first aspect of the present disclosure, an information processing device has an acquisition unit that acquires information regarding wireless communication of a backhaul link between a first base station and a second base station and information regarding wireless communication of an access link between the second base station and a user terminal, a control unit that determines a first wireless communication method of the backhaul link and a second wireless communication method of the access link based on the information acquired by the acquisition unit, and a transmission unit that transmits information indicating the first wireless communication method determined by the control unit to at least one of the first base station and the second base station, and transmits information indicating the second wireless communication method to at least one of the second base station and the user terminal.

[0016] In addition, a second aspect of the present disclosure provides an information processing method that acquires information regarding wireless communication of a backhaul link between a first base station and a second base station and information regarding wireless communication of an access link between the second base station and a user terminal, determines a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the acquired information, transmits information indicating the determined first wireless communication method to at least one of the first base station and the second base station, and transmits information indicating the second wireless communication method to at least one of the second base station and the user terminal.

[0017] In addition, in a third aspect of the present disclosure, there is provided a program for causing an information processing device to execute the following processes: acquiring information regarding wireless communication of a backhaul link between a first base station and a second base station, and information regarding wireless communication of an access link between the second base station and a user terminal; determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the acquired information; and transmitting information indicating the determined first wireless communication method to at least one of the first base station and the second base station, and transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal.

[0018] Also, in a fourth aspect of the present disclosure, a wireless communication system is provided having a first base station, a second base station, and a user terminal. The wireless communication system includes an acquisition unit that acquires information related to wireless communication of a backhaul link between the first base station and the second base station and information related to wireless communication of an access link between the second base station and the user terminal, a control unit that determines a first wireless communication method of the backhaul link and a second wireless communication method of the access link based on the information acquired by the acquisition unit, and a transmission unit that transmits information indicating the first wireless communication method determined by the control unit to at least one of the first base station and the second base station, and transmits information indicating the second wireless communication method to at least one of the second base station and the user terminal. Effect of the Invention

[0019] According to one aspect, wireless communication can be performed more appropriately. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a heterogeneous network (HetNet). [Diagram 2] FIG. 2 is a diagram illustrating an example of an IAB layer structure and an interface. [Diagram 3] FIG. 13 is a diagram showing an example of an IAB link. [Figure 4] FIG. 1 is a diagram illustrating an example of a configuration of an information processing device according to an embodiment. [Diagram 5] 10 is a flowchart illustrating an example of processing of the information processing device according to the embodiment. [Figure 6] FIG. 11 is a diagram showing an example of a process for selecting between single-carrier FDMA and OFDMA according to an embodiment. [Figure 7] FIG. 11 is a diagram illustrating an example of a process for adaptively controlling a coding rate and a signal space arrangement according to the embodiment. [Figure 8] FIG. 2 is a diagram showing an example of a method for multiplexing a reference signal in OFDMA according to an embodiment. [Figure 9]1 is a diagram showing an example of a method for multiplexing a reference signal in single-carrier FDMA according to an embodiment. FIG. [Figure 10] 11 is a diagram showing an example of a process for adaptively controlling a multiplexing method for control information when OFDMA according to an embodiment is used; FIG. [Figure 11] FIG. 11 is a diagram showing an example of a process for adaptively controlling a multiplexing method for control information when DFT-spread OFDM according to an embodiment is used. [Figure 12] FIG. 11 is a diagram showing an example of a process for adaptively controlling a multiplexing method for control information when DFT-spread OFDM according to an embodiment is used. [Figure 13] FIG. 1 is a diagram illustrating an example of a transmission frame configuration when using Faster-than-Nyquist (FTN) according to an embodiment. [Figure 14] 11 is a flowchart illustrating an example of a resource allocation process for an uplink of an access link according to the embodiment. [Figure 15] 11 is a flowchart illustrating an example of a resource allocation process for a downlink of an access link according to the embodiment. [Figure 16] FIG. 1 is a diagram illustrating an example of a configuration of an information processing device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The principles of the present disclosure are described with reference to some exemplary embodiments. It should be understood that these embodiments are set forth for illustrative purposes only, to aid those skilled in the art in understanding and practicing the present disclosure, without implying any limitation on the scope of the present disclosure. The disclosure described herein may be implemented in various ways other than those described below.

[0022] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. <Configuration> Fig. 4 is a diagram showing an example of the configuration of an information processing device 10 according to an embodiment. In Fig. 4, the information processing device 10 has an acquisition unit 11, a control unit 12, and a transmission unit 13. Note that the configuration shown in Fig. 4 is merely an example. As long as the processing of the present disclosure can be executed, the names of the respective units may be any names.

[0024] The acquisition unit 11 acquires various information from a storage device inside the information processing device 10 and an external device. The acquisition unit 11 acquires, for example, information on wireless communication of a backhaul link between a macrocell base station and a small cell base station overlaid in a macrocell of the macrocell base station. The acquisition unit 11 also acquires, for example, information on wireless communication of an access link between at least one of the macrocell base station and the small cell base station and a user terminal.

[0025] The control unit 12 performs various controls. For example, based on the information acquired by the acquisition unit 11, the control unit 12 determines a first wireless communication method for the backhaul link and a second wireless communication method for the access link.

[0026] The transmitter 13 transmits (outputs) various kinds of information in accordance with instructions from the controller 12. For example, the transmitter 13 transmits information indicating the first wireless communication method determined by the controller 12 to at least one of the macrocell base station and the small cell base station, and transmits information indicating the second wireless communication method to at least one of the macrocell base station, the small cell base station, and the user terminal. This makes it possible to perform wireless communication more appropriately.

[0027] <System configuration> The system configuration of the wireless communication system 1 according to the embodiment may be the same as the heterogeneous network (HetNet) of Fig. 1. In this case, the information processing device 10 may be provided, for example, inside the devices such as the macrocell base station 20A, the small cell base station 20B, and the small cell base station 20C forming the heterogeneous network (HetNet) shown in Fig. 1, or in the upper station 40. In addition, the information processing device 10 according to the embodiment may be provided as a separate device outside the devices such as the upper station 40, the macrocell base station 20A, and the small cell base station shown in Fig. 1. Note that the number of base stations 20 and user terminals 30 is not limited to the example of Fig. 1.

[0028] In the heterogeneous network according to the embodiment, the small cell base station 20B, etc. may be arranged within the coverage area of ​​the macro cell base station 20A. In this case, the small cell base station 20B, etc. may be installed at a position whose coverage area is an area where wireless communication traffic is relatively high within the coverage area of ​​the macro cell base station 20A. In addition, in the heterogeneous network according to the embodiment, the backhaul link between the base stations and the access link between the base station and the user terminal may perform wireless communication using the same or different frequency spectrum.

[0029] The base station 20 and the user terminal 30 are connected so as to be able to communicate with each other via wireless communication such as a fifth generation mobile communication system (5G), Beyond 5G, a fourth generation mobile communication system (4G), or a wireless local area network (LAN).

[0030] Note that the term "base station" (BS) used in this disclosure refers to a device that can provide (host) a coverage area (cell) in which user terminals 30 can communicate. Examples of the base station 20 include, but are not limited to, a Node B (NodeB or NB), an Evolved Node B (eNodeB or eNB), a next-generation Node B (gNB), a Remote Radio Unit (RRU), a Radio Head (RH), a Remote Radio Head (RRH), and a low-power node (e.g., a femto node, a pico node), etc.

[0031] The term "User Equipment" (UE) as used in this disclosure refers to any device having wireless or wired communication capabilities. Examples of user equipment 30 include, but are not limited to, smartphones, cellular phones, mobile phones, Internet of Things (IoT) devices, personal computers, desktops, personal digital assistants (PDAs), portable computers, image capture devices such as digital cameras, gaming devices, music storage and playback devices, or Internet appliances that enable Internet access and browsing, etc.

[0032] Communications described in this disclosure may conform to any suitable standard, including, but not limited to, Beyond 5G, 5G (NR: New Radio), 4G (LTE Advanced, WiMAX2), Long Term Evolution (LTE: Long Term Evolution), Wideband Code Division Multiple Access (W-CDMA), Code Division Multiple Access (CDMA), Global System for Mobile (GSM), etc. Additionally, communications may be performed according to any generation of communications protocols now known or developed in the future.

[0033] In addition to normal data communication, the base station 20 may transmit a downlink reference signal (RS) to the user terminal 30 by broadcast, multicast, or unicast. Similarly, the user terminal 30 may transmit an RS to the base station 20 on the uplink. As used herein, "downlink" refers to a link from the macrocell base station 20A to the user terminal 30, and "uplink" refers to a link from the user terminal 30 to the macrocell base station 20A.

[0034] For example, the downlink RS is used by the user terminal 30 for beam sweeping, channel estimation, demodulation, and other operations for communication. In general, the RS is a signal sequence (also called an "RS sequence") known by both the base station 20 and the user terminal 30. For example, the base station 20 generates and transmits the RS sequence based on a certain rule, and the user terminal 30 estimates the RS sequence based on the same rule. Examples of the RS include, but are not limited to, a De-Modulation Reference Signal (DM-RS), which is a reference signal for demodulation at the downlink or uplink receiving side, a Channel State Information-Reference Signal (CSI-RS), which is a reference signal transmitted to measure the state of a wireless channel at the receiving side, a Sounding Reference Signal (SRS), a Phase Tracking Reference Signal (PTRS), a fine time and frequency tracking reference signal (TRS), and the like.

[0035] <Processing> Next, an example of the process of the information processing device 10 according to the embodiment will be described with reference to Fig. 5. Fig. 5 is a flowchart showing an example of the process of the information processing device 10 according to the embodiment.

[0036] In step S1, the acquisition unit 11 of the information processing device 10 acquires information specific to each base station 20 (hereinafter also referred to as "cell-site specific information" as appropriate) from an internal or external storage unit of the information processing device 10, or from each base station 20. The cell-site specific information may be measured when the base station 20 is installed. Also, it may be measured (updated) again when a new base station 20 is installed.

[0037] The following process may be executed, for example, when a wireless link is set up to start communication with the user terminal 30. It may also be executed when the degree of change in the information related to wireless communication measured by each base station 20 and each user terminal 30 is equal to or greater than a threshold.

[0038] The cell site specific information may include, for example, at least one of information indicating one or more frequency spectra that the base station 20 can use for wireless communication and information indicating the width (range, size) of the coverage area of ​​the base station 20 for each type of link. The cell site specific information may also include, for example, information indicating the distance between one base station 20 and other surrounding base stations 20 (for example, the distance between cell sites, the distance between the centers of each cell) (for example, the propagation loss between each base station). The cell site specific information may also include, for example, information indicating the distribution of traffic between the cell of one base station 20 and the cell of the surrounding other base station 20 for each type of link. The cell site specific information may also include, for example, information indicating the PAPR (Peak to Average Power Ratio) of a transmission signal for each type of link.

[0039] The link type is a type of link to which the base station 20 allocates wireless communication resources. The link type may include an uplink of a backhaul link, a downlink of a backhaul link, an uplink of an access link, and a downlink of an access link. Note that the base station 20 is set with a link type associated with a physical cell identifier (PCID) of another base station 20 in the vicinity.

[0040] One or more frequency spectra that the base station 20 can use for wireless communication may be set in advance in the base station 20. Based on each frequency spectrum that the base station 20 can use for wireless communication, the distance attenuation (long-term fluctuation) can be estimated by a distance attenuation formula.

[0041] Information on the size of the coverage area (cell radius) of the base station 20 may be stored in advance in the base station 20. Information on the distance between one base station 20 and other base stations 20 in the vicinity may be stored in the one base station 20 in advance.

[0042] The PAPR for each modulation scheme with respect to the number of subcarriers of the transmission signal can be calculated from the transmission bandwidth of the OFDM. The PAPR also differs depending on the roll-off rate of the waveform shaping filter that uses a root raised cosine filter. Therefore, the information processing device 10 may calculate and tabulate (store) in advance the PAPR with respect to the modulation scheme and the roll-off rate of the waveform shaping filter for single carrier FDMA and OFDM with different numbers of subcarriers in the transmission band.

[0043] Next, the acquisition unit 11 of the information processing device 10 acquires information related to wireless communication measured by each base station 20 and each user terminal 30 (step S2). Note that, when wireless communication is connected (when online), each base station 20 and each user terminal 30 measures information related to wireless communication using a reference signal, for example, at a predetermined period, and transmits the measured information to the information processing device 10. The information related to wireless communication may include, for example, phase noise of the transmitter and receiver, power delay profile (LOS / NLOS), and information on the moving speed of the user terminal 30.

[0044] Regarding phase noise in transmitters and receivers, in the high frequency spectrum of the millimeter wave band, phase noise caused by frequency fluctuations in a local oscillator that uses a phase locked loop (PLL) is one of the main causes of degradation in characteristics. Phase noise in a local oscillator is caused by the reference clock signal, noise in the PLL elements, and the voltage controlled oscillator (VCO). The power spectrum density (PSD) of the phase noise caused by the reference clock signal attenuates quadratically with respect to the frequency f (1 / f 2. Note that " / " here indicates division.) It has a frequency characteristic of 20dB / decade (every time the frequency increases by a factor of 10, the amplitude of the passing signal is attenuated by 20dB).

[0045] The PSD of the phase noise caused by the PLL elements attenuates linearly with frequency f (1 / f. Note that " / " here indicates division). It has a frequency characteristic of 10 dB / decade. The PSD of the phase noise caused by the VCO attenuates quadratically with frequency (1 / f 2 Here, " / " indicates division. Phase noise has a frequency characteristic of 20 dB / decade and decays in third order (1 / f 3 (Note that " / " here indicates division.) This includes phase noise with a frequency characteristic of 30 dB / decades. It has been reported that at frequencies lower than the PLL loop bandwidth, the phase noise caused by the reference clock signal and PLL elements is dominant, while at frequencies higher than the PLL loop bandwidth, the phase noise caused by the two types of VCOs is dominant.

[0046] Each base station 20 and each user terminal 30 may calculate the power of the phase noise by using a reference signal. Also, each base station 20 and each user terminal 30 may calculate the power of the phase noise based on the power spectrum density (PSD) of the phase noise of a local oscillator using a PLL frequency synthesizer.

[0047] The power delay profile (LOS / NLOS) may be measured using, for example, a reference signal. Based on the power delay profile, the received power of the direct wave, the Rice factor, the rms (root mean square) delay spread, the maximum path delay time, and the like can be measured. The received power of the direct wave makes it possible to distinguish whether the channel is an LOS channel, an NLOS channel, or a mixed LOS / NLOS channel. The moving speed of the user terminal 30 may be calculated based on, for example, the Doppler frequency measured using the reference signal.

[0048] Next, the control unit 12 of the information processing device 10 determines various parameters of the physical layer of the wireless communication of the backhaul link and the access link based on the information acquired by the acquisition unit 11 (step S3). Here, the information processing device 10 may determine various parameters of the wireless communication to be applied to each base station 20 and each user terminal 30 based on, for example, the cell site specific information acquired in step S1, the information related to the wireless communication acquired in step S2, and the traffic requirement conditions. The traffic requirement conditions may include, for example, requirements such as delay (transmission delay), error rate, and data rate. The traffic requirement conditions may be specified by, for example, the user terminal 30. Also, the traffic requirement conditions may be set in, for example, each base station 20.

[0049] Next, the transmission unit 13 of the information processing device 10 transmits the determined parameters to each base station 20 and each user terminal 30 (step S4). This allows each device to apply various more appropriate wireless communication parameters.

[0050] An example of the process of determining various parameters for wireless communication in step S3 will be described below. Note that the following processes can be executed in appropriate combination.

[0051] (An example of adaptively controlling the physical channel multiplexing method (waveform)) The information processing device 10 may adaptively determine a physical channel multiplexing method (waveform) based on the acquired information. In this case, when the frequency spectrum used for the backhaul link is higher than a threshold and the distance between each base station is longer than a threshold, the information processing device 10 may select DFT (Discrete Fourier transform)-spread OFDM (an example of single carrier FDMA) as the physical channel multiplexing method. This allows, for example, wireless communication of the backhaul link in a LOS environment with a relatively large propagation loss to be appropriately performed.

[0052] In addition, for the backhaul link, when the distance between the macrocell base station 20 and the small cell base station 20 is shorter than a threshold value and the power of the multipath signal caused by reflection and scattering from surrounding objects and buildings in addition to the direct wave is higher than a threshold value, the information processing device 10 may select OFDMA as the physical channel multiplexing method.

[0053] In addition, the information processing device 10 may select DFT-spread OFDM as a physical channel multiplexing method in the access link when the applied frequency spectrum is higher than a threshold and the coverage area is larger than a threshold (the cell radius is larger than a threshold). In other cases, the information processing device 10 may select OFDMA in the access link.

[0054] A typical propagation environment for wireless backhaul is line-of-sight (LOS) propagation. In the wireless backhaul link of a practical system, ultra multilevel modulation, polarized multi-input multi-output (MIMO), and LOS-MIMO are applied to increase speed and capacity. On the other hand, in the NR wireless interface, when multi-antenna MIMO is used, OFDMA is adopted for both uplink and downlink. Therefore, in the IAB wireless interface, OFDMA is used for both uplink and downlink including the backhaul link. However, OFDMA has a drawback that it has a higher PAPR than single-carrier FDMA and is less resistant to phase noise. Therefore, the transmission back-off of the power amplifier of the transmitter limits the distance between base stations that can provide services. On the other hand, according to the present disclosure, the limitation on the distance between base stations that can provide services can be reduced. Therefore, wireless communication can be performed more appropriately.

[0055] Fig. 6 is a diagram showing an example of a process for selecting between single-carrier FDMA and OFDMA according to an embodiment. In the example of Fig. 6, the information processing device 10 first converts a single-carrier FDMA signal into the frequency domain by DFT (Discrete Fourier transform). Then, the information processing device 10 generates the signal by using DFT-spread OFDM, which maps each frequency component (corresponding to a subcarrier in OFDMA) to an assigned frequency component in the frequency domain. By replacing the serial / parallel (S / P) conversion process of OFDMA with DFT, the generation of the single-carrier FDMA signal and the OFDMA signal can be easily switched.

[0056] When OFDMA is selected, the information processing device 10 may use frequency domain spreading if the delay spread is large, i.e., frequency selectivity is large. Also, the information processing device 10 may use time domain spreading if the Doppler frequency measured by the user terminal 30 is higher than a threshold value. This makes it possible to obtain a time diversity effect when, for example, the moving speed of the user terminal 30 is relatively fast and therefore the amplitude and movement fluctuation in a slot section consisting of multiple OFDM symbols are large. In this case, the information processing device 10 may perform two-dimensional spreading in the frequency and time domains using the two-dimensional Walsh-Hadamard code allocation method proposed in Non-Patent Document 5.

[0057] (Example of controlling the channel coding rate and the signal space arrangement for mapping bits after channel coding) FIG. 7 is a diagram showing an example of a process of adaptively controlling the coding rate and the signal space arrangement according to the embodiment. The information processing device 10 may determine at least one of a set of coding rates for channel coding and a set of signal space arrangements to which bits after channel coding are mapped, based on the acquired information. In this case, the information processing device 10 may set in advance a signal space arrangement set having a plurality of modulation multi-level numbers (the number of signal points in the signal space arrangement) for different signal space arrangements, as shown in FIG. 7. In this case, the information processing device 10 may prepare modulation multi-level numbers such as BPSK (Binary Phase-Shift Keying), QPSK (Quadrature Phase Shift Keying), 16QAM, 64QAM, 256QAM, and 1024QAM, as examples. The user terminal 30 may use, as the type of signal space arrangement, a Rectangular / CrossQAM signal space arrangement adopted in a practical cellular system, a CircularQAM signal space arrangement composed of a plurality of concentric circles with different radii, and the like. The information processing device 10 may set a signal spatial arrangement for each of the signal spatial arrangements for the number of various signal levels described above. Note that the Circular QAM signal spatial arrangement has different PAPR and resistance to phase noise depending on the number of rings and the number of signal points on the rings. Therefore, the information processing device 10 may set different Circular QAM signal spatial arrangements according to the same modulation level.

[0058] The information processing device 10 may select a signal space arrangement set from among a plurality of signal space arrangement sets based on cell site specific information and phase noise of a transmitter and a receiver. Then, the information processing device 10 performs adaptive rate control by dynamically (adaptively) selecting a modulation scheme (modulation multi-level number) and a channel coding coding rate (MCS, Modulation and Coding Scheme) according to a received SNR for each TTI (Transmission Time Interval) for the selected signal space arrangement set.

[0059] The NR radio interface uses a RectangularQAM signal space constellation. In terms of thermal noise and interference, the RectangularQAM signal space constellation, which maximizes the Euclidean distance between signal points, can achieve the best error rate. However, the 5G and Beyond 5G systems are expected to use frequency spectra up to about 100 GHz. In the future, frequency spectra above 100 GHz are also being considered.

[0060] In the high frequency spectrum of the millimeter wave band, propagation loss is large, so that the Rectangular QAM signal space constellation with high PAPR requires a large transmission back-off of the power amplifier of the transmitter. In addition, in the frequency spectrum of the millimeter wave band, the most important factor of degradation of the error rate is phase noise caused by frequency fluctuation of the local oscillator. The Rectangular QAM signal space constellation has low resistance to phase noise. On the other hand, according to the present disclosure, the resistance to phase noise can be improved. Therefore, wireless communication can be performed more appropriately.

[0061] In addition, for Gaussian noise and interference, the rectangular signal space arrangement with the largest Euclidean distance between signal points can reduce the required received SNR the most. 2k+1In the case of k = 1, where k is an integer equal to or greater than 1, the signal space arrangement is not square, but cross-shaped, and is therefore called CrossQAM. RectangularQAM allows Gray mapping, but CrossQAM lacks signal points at the corners, so Gray mapping cannot be performed for all signal points, resulting in pseudo-Gray mapping. Rectangular / CrossQAM signal space arrangements have a small phase angle between signal points, so they are not resistant to phase noise that only produces phase fluctuations. In addition, Rectangular / CrossQAM has a large difference between the minimum and maximum amplitudes, so it produces high peak power when band-limited by a root-raised cosine filter. On the other hand, CircularQAM, which has a concentric signal space arrangement, has a larger phase angle between adjacent signal points on the same ring than Rectangular / CrossQAM, so it has high resistance to phase noise. In addition, CircularQAM allows independent mapping of the bits representing the amplitude and phase components. The amplitude ratio of the concentric circles can be set independently of the phase angle. In particular, in the case of a signal space constellation in which the same number of signal points with the same phase are arranged on different concentric circles, when a signal point with the same phase on an adjacent concentric circle is erroneously decoded, only the amplitude information is erroneous, so that the erroneous amplitude bit can often be corrected by the coding gain of the error correction coding (channel coding). Therefore, the interval between adjacent concentric circles can be shortened, and the interval between the innermost concentric circle and the outermost concentric circle can be narrowed. As a result, the PAPR can be suppressed lower than that of Rectangular / CrossQAM. In addition, the phase margin can be increased by aligning the phases of signal points on multiple different concentric circles. Therefore, the resistance to phase noise can be increased compared to Rectangular / CrossQAM.

[0062] In addition, phase noise is estimated using reference signal symbols multiplexed at regular intervals onto time-domain information symbols. If the transmitted reference signal is represented as s(l) (l represents the index of the reference signal symbol), the received signal r(l) is expressed by the following equation (1). Here, θ represents the phase noise and w represents the thermal noise.

number

[0063] Therefore, the information processing device 10 can estimate the phase noise term by multiplying the received signal by the complex conjugate of the reference signal using the following equation (2): Here, * denotes a complex conjugate.

number

[0064] However, noise components such as receiver noise and background noise are added to the estimated phase noise. Therefore, the information processing device 10 may average the phase noise estimated by a plurality of reference signal symbols in order to remove the noise components. In this case, it is required to average the phase noise estimate values ​​of the reference signal symbols in a range in which the correlation of the phase noise in the time domain is high. Therefore, the information processing device 10 may use a method of estimating the phase noise estimate value of a preset time interval by using a moving average, a method using a Wiener filter, or the like.

[0065] Furthermore, the information processing device 10 can estimate the phase noise with high accuracy by using the determined information symbol in addition to the reference signal symbol. Specifically, the phase noise may be estimated by phase locked loop (PLL) phase noise estimation using decision bits before or after decoding of error correction coding (channel coding). In this case, the information processing device 10 can generate a highly accurate decision feedback symbol based on the coding gain of the error correction code by using decision bits after error correction decoding.

[0066] (An example of adaptively controlling the multiplexing method of reference signals (pilot signals)) Reference signals are required for estimating channel response to generate equalization weights for multipath fading channels, estimating phase noise, estimating channel quality indicator (CQI), and estimating channel state information (CSI). The NR radio interface uses a demodulation reference signal (DM-RS: Demodulation Reference Signal), a CSI measurement reference signal (CSI-RS), and a phase noise measurement reference signal (PT-RS: Phase Tracking RS). The NR radio interface reference signals are configured based on the OFDMA waveform, and only the multiplexing method of the reference signals according to the number of transmit antennas is specified.

[0067] As described above, the information processing device 10 according to the embodiment of the present disclosure may adaptively select, as a physical channel multiplexing method (waveform), OFDMA, DFT-spread OFDM, etc. In this case, the information processing device 10 may control a multiplexing method of a CSI (Channel State Information)-RS for measuring reception quality and a DM (Demodulation)-RS for demodulation used in synchronous detection, according to the selected physical channel multiplexing method.

[0068] In addition, the information processing device 10 may adaptively control the multiplexing method and multiplexing interval of a phase tracking reference signal (PT-RS: Phase Tracking RS) based on information indicating the phase noise and power delay profile (frequency offset) measured in each base station 20 and each user terminal 30.

[0069] FIG. 8 is a diagram showing an example of a multiplexing method of a reference signal in OFDMA according to an embodiment. The reference signal multiplexing method shown in FIG. 8 is based on the reference signal multiplexing method of the NR radio standard. The multiplexing method of CSI-RS and DM-RS when using OFDMA of the present disclosure may be the same as that of the NR radio interface. In addition to the CSI-RS and DM-RS, the NR radio interface employs a PT (Phase Tracking)-RS for estimating phase noise and frequency offset. The DM-RS specifies an orthogonal reference signal that uses frequency division multiplexing (FDM) and code division multiplexing (CDM) according to the number of transmission antennas used for MIMO multiplexing. The PT-RS is sparsely multiplexed in the frequency domain. The time domain is multiplexed every 4, 2, and 1 OFDM symbols according to the MCS. Since the influence of phase noise is small in a low MCS such as QPSK, the insertion loss of the reference signal can be kept low by multiplexing the PT-RS every 4 OFDM symbols. On the other hand, since multi-level modulation such as 256QAM has a small phase margin, the PT-RS is multiplexed every OFDM symbol, that is, into consecutive OFDM symbols.

[0070] The information processing device 10 controls the multiplexing method of the CSI-RS and the DM-RS depending on whether the waveform is OFDMA or DFT-spread OFDM. Furthermore, the information processing device 10 may adaptively control the multiplexing interval of the time domain of the PT-RS depending on the measured phase noise and the modulation scheme (MCS).

[0071] FIG. 9 is a diagram showing an example of a multiplexing method of a reference signal in single-carrier FDMA according to an embodiment. In the uplink of the NR radio interface, OFDMA is adopted in the case of multi-antenna transmission (MIMO). Therefore, in the uplink of the NR radio interface, DM-RS and Sounding Reference Signal (SRS) for OFDMA are specified. DFT-spreadofdm, which is single-carrier FDMA, is adopted in the 3GPP Release 15 specifications only for one-stream transmission (SIMO). Therefore, the DM-RS and SRS multiplexing method of DFT-spreadOFDM in the LTE uplink is applied. Therefore, in the NR radio interface of the Release 15 specifications, a new reference signal of DFT-spreadOFDM is not specified.

[0072] The information processing device 10 transmits the DM-RS to the N DM The CSI-RS is multiplexed at the end of every few slots, or at the beginning of a slot and the DM-RS is multiplexed at the Nth symbol interval. CSI On the other hand, the information processing device 10 multiplexes the PT-RS into N consecutive information symbol intervals. PT Multiplexed onto the symbol. N PT is 1 or a decimal (number symbol). PT The symbol block interval is adapted and controlled according to the frequency spectrum and MCS to be applied. As described above, the multiplexing method of DM-RS in the present disclosure is different from the multiplexing method of DM-RS in DFT-spread OFDM in the LTE uplink. On the other hand, the SRS in LTE is multiplexed in an FFT (Fast Fourier Transformation) block at the end of a subframe. Therefore, in the embodiment of the present disclosure, when the CSI-RS is multiplexed at the end of a slot every few slots, the configuration is the same as the multiplexing method of SRS in LTE.

[0073] PT-RS is not specified in the LTE radio interface. In single-carrier DFT-spread OFDM, an equalizer is required to compensate for waveform distortion caused by multipath interference. When using time domain equalization (TDE), N DM When using frequency domain equalization (FDE), N DM is the length of the number of FFT stages. In the case of MIMO multiplexing using multiple transmitting antennas, antenna-specific orthogonal CSI-RS and DM-RS are required. In the case of CSI-RS, generally, a number of symbols equal to the number of transmitting antennas is prepared to generate an orthogonal reference signal. Alternatively, a method can be used in which an orthogonal code is used to spread a reference signal with a number of symbols equivalent to the number of transmitting antennas in the time domain, and then multiplexed in the code domain. DM-RS requires N DM DM-RS with the number of symbols is prepared for the number of transmitting antennas, and orthogonal DM-RS is generated by TDM multiplexing. However, when generating DM-RS for the number of transmitting antennas by TDM, the required resources increase to the number of transmitting antennas. Therefore, orthogonal DM-RS in the frequency domain can be generated by Distributed FDM multiplexing in the frequency domain. Distributed FDM is a method of allocating frequency components at a constant period in the frequency domain, and does not result in an increase in peak power. A method of generating a Distributed FDM signal in the frequency domain by repeatedly multiplexing symbol blocks in the time domain has been proposed as Interleaved FDMA (IFDMA). Also, N DM A DistributedFDM signal can be generated by converting the DM-RS of a symbol into a frequency domain signal and mapping it to frequency component (subcarrier) positions discretely at regular intervals in the frequency domain.

[0074] (An example of adaptively controlling the multiplexing method of control information) The information processing device 10 may adaptively control the multiplexing method of the control information based on the acquired information. The control information may be, for example, resource allocation (grant) information, modulation scheme, transport block size, retransmission acknowledgement (Ack), non-acknowledgement (Nack), or other layer 1 or layer 2 control information. The layer 1 and layer 2 control information are necessary for demodulation and decoding of a shared channel that transmits user information. Therefore, the control signal may be TDM-multiplexed at the beginning of a slot in both OFDMA and DFT-spread OFDM (single carrier).

[0075] In the LTE and NR radio interfaces, the method of multiplexing control information of Layer 1 and Layer 2, such as resource allocation (grant) information, modulation scheme, transport block size, and retransmission acknowledgement (Ack) / non-acknowledgement (Nack), is determined by the number of transmitting antennas.

[0076] 10 is a diagram showing an example of a process for adaptively controlling a multiplexing method of control information when OFDMA according to an embodiment is used. When OFDMA is used, the information processing device 10 may determine a multiplexing method of control information according to, for example, a frequency spectrum used in wireless communication, the size of each coverage area, the distance between each base station, a directional beam gain, a quality required for the control information (for example, an error rate), and the like.

[0077] In this case, the information processing device 10 may select one mode from, for example, the following three multiplexing modes. In the first mode, TDM multiplexing is used in which a control signal is multiplexed in a section of one or several OFDM symbols at the beginning of a slot. In a downlink radio interface of LTE using OFDMA, a control channel is multiplexed from the beginning OFDM symbol of a slot up to a maximum of three OFDM symbol positions. Therefore, the embodiment of TDM multiplexing of the present disclosure is similar to the LTE or NR radio interface.

[0078] In the second mode, the control information is multiplexed in a preset subcarrier position using FDM multiplexing. In FDM multiplexing, for example, control information is multiplexed in one or several subcarriers in a resource block. FDM multiplexing can increase the transmission power of a specific subcarrier by changing the power allocation between subcarriers for a fixed transmission power of the base station 20 or user terminal 30. By increasing the power of the subcarrier multiplexed with the control information, the reach of the radio wave can be increased or high quality reception can be achieved. In the case of FDM multiplexing, the processing delay is longer than in the above-mentioned TDM multiplexing. Note that in the LTE and NR radio interfaces, the control information of OFDMA is TDM multiplexed, and FDM multiplexing of the control information is not specified.

[0079] In the third mode, resource block multiplexing is used in which control information is multiplexed over the entire resource block of one slot in order to increase the reach of control information or to achieve high-quality reception. By performing bit-level or symbol-level repetition, the required reception SNR to meet the required error rate can be lowered. Alternatively, a low error rate can be achieved for the same reception SNR. Instead of bit or symbol repetition, ultra-low rate error correction coding (channel coding) may be used. In addition, the NR radio interface's uplink control channel (PUCCH: Physical Uplink Control Channel) adopts a minimum channel coding rate of 0.08 (approximately 1 / 12. Note that " / " here indicates division). Symbol repetition is also adopted to improve the reception SNR. In either method, the resources of the radio section increase, so the point that the resources of the entire resource block are allocated to the control information is different from the NR radio interface.

[0080] 11 and 12 are diagrams showing an example of a process for adaptively controlling a multiplexing method of control information when DFT-spread OFDM according to an embodiment is used. When DFT-spread OFDM is used, the information processing device 10 may determine a multiplexing method of control information according to, for example, a frequency spectrum used in wireless communication, the size of each coverage area, the distance between each base station, a directional beam gain, a quality required for the control information (for example, an error rate), and the like.

[0081] In this case, the information processing device 10 may select one of the following two multiplexing modes. In the first mode, as shown in FIG. 11, the control information is multiplexed at one or several symbol positions at the beginning of the slot by TDM multiplexing. In the second mode, as shown in FIG. 12, the control information is multiplexed at the entire resource block of one slot by resource block multiplexing to increase the reach of the control information or to realize high-quality reception. As in the case of OFDMA, the required reception SNR for satisfying the required error rate can be lowered by using bit-level or symbol-level repetition or ultra-low-rate error correction coding (channel coding). Alternatively, a low error rate can be realized for the same reception SNR. As described above, in the NR radio interface, DFT-spread OFDM is adopted only in the case of uplink one-stream transmission (SIMO without MIMO). Therefore, the control information multiplexing of DFT-spread OFDM is performed in accordance with the provisions of the control information multiplexing of the PUCCH of LTE. Since the PUCCH of LTE is narrowband, it is configured to perform frequency hopping between two slots in one subframe. Also, since the subframe length is as long as 1 ms, control information from multiple users is CDMA-multiplexed using cyclically shifted Zadoff-Chu sequences. Control information from different users is multiplexed using Zadoff-Chu sequences with different cyclic shift amounts. On the other hand, in the embodiment of the present disclosure, control information is TDM-multiplexed into a shared channel that transmits user information. When DFT-spread OFDM is applied to the downlink, control information is TDM-multiplexed into the shared channel in this way. The same is true when applied to the uplink, but when Ack / Nack information of the downlink shared channel (PDSCH) is transmitted in the uplink, if there is no user information to transmit in the buffer of the user terminal 30, control information is multiplexed over the entire slot. In this case, symbol repetition or a low-rate channel coding rate is used. By multiplexing control information resources over the entire slot, it is possible to reduce transmission power.

[0082] (An example of adaptively controlling the symbol interval and the roll-off rate of a raised cosine roll-off filter) The information processing device 10 may adaptively control the symbol interval and the roll-off rate of the raised cosine roll-off filter based on the acquired information. Fig. 13 is a diagram showing an example of a transmission frame configuration when using Faster-than-Nyquist (FTN) according to the embodiment. In Fig. 13, N Symbol is the number of samples in a symbol, and N OL is the number of samples in the overlap section. When using Faster-than-Nyquist (FTN), the transmission frame 131 corresponds to a single carrier symbol in the case of DFT-spread OFDM. In addition, in the case of OFDMA, the transmission frame 131 corresponds to an OFDM symbol per subcarrier. By using FTN, time domain symbols can be overlapped and multiplexed at intervals shorter than the Nyquist interval. Therefore, the number of multiplexed symbols per slot increases, and the frequency utilization efficiency can be improved.

[0083] Non-Patent Document 6 shows that the Euclidean distance between signal points does not change even if the inter-symbol interval is shortened to 0.802T, with the Nyquist interval being T. When the inter-symbol interval is shortened to 0.802T, the spectral efficiency can be increased by about 25%. On the other hand, the PAPR depends on the waveform, modulation method, band limiting factor of the waveform shaping filter, and the like. In practical wireless communication systems such as cellular systems, a root raised cosine filter (RRCF) is generally used as the waveform shaping filter. As the roll-off rate of the RRCF decreases (approaches 0), it approaches an ideal low-pass filter, so that a steep attenuation characteristic can be realized in the frequency domain. Therefore, the occupied signal band within the system band (allocated band) can be increased. On the other hand, the time domain waveform has a large amplitude fluctuation, and the time range in which the inter-symbol interference is caused increases. Therefore, as the roll-off rate decreases, the PAPR of the transmission signal increases.

[0084] The information processing device 10 lengthens the symbol length without changing the number of symbols per slot by using FTN. The longer the symbol length, the shorter the subcarrier interval (interval between frequency components). Therefore, when the number of subcarriers (number of frequency components) is the same, the signal-occupied band can be narrowed. Therefore, the roll-off rate for accommodating the frequency spectrum within the system band can be increased, and the PAPR can be reduced. The information processing device 10 may adaptively control the symbol interval and the roll-off rate of the RRCF according to, for example, the frequency spectrum used in wireless communication, the size of each coverage area, the distance between each base station, the directional beam gain, the quality required for control information (for example, error rate), and the like. When the distance between each base station is longer than a threshold value for the backhaul link, the information processing device 10 may increase the roll-off rate by using FTN. This achieves, for example, a low PAPR. On the other hand, when the distance between each base station is not longer than a threshold value for the backhaul link, the information processing device 10 may multiplex symbols at Nyquist intervals without applying FTN. This makes it possible to reduce the processing load on the base station 20, for example.

[0085] (Regarding resource allocation of access links when the backhaul link and the access link use the same frequency spectrum and IAB nodes perform multi-hop communication) In IAB, multi-hop is adopted. Therefore, it is required to consider resource allocation in multiple IAB nodes in the case of multi-hop. When different links are multiplexed by TDM, the delay increases with the increase in the number of hops. For example, when focusing on the access link between the IAB node and the user terminal 30, if the interval between the allocation slots of the downlink and the uplink becomes long, the RTT (Round Trip Time) increases, and the delay of resource allocation and retransmission control increases. The same is true for the backhaul link. Therefore, it is required to consider the slot allocation of the uplink and downlink in each access link and backhaul link while taking into account the delay.

[0086] In addition, when TDM is applied, in the case of multi-hop, although the orthogonality of links at each IAB node is guaranteed, it is also necessary to consider resource allocation and transmission power control to reduce cross-link interference between links of IAB nodes that are separated by a number of hops.

[0087] An example of resource allocation processing for the uplink of the access link when the backhaul link and the access link use the same frequency spectrum and an IAB node (for example, small cell base stations 20B and 20C) performs multi-hop communication will be described with reference to Fig. 14. Fig. 14 is a flowchart showing an example of resource allocation processing for the uplink of the access link according to the embodiment.

[0088] As shown in Fig. 14, when the backhaul link and the access link use the same frequency spectrum and multiple small cell base stations perform multi-hop communication, the information processing device 10 may determine whether or not to permit connection of the access link based on the degree of interference between the backhaul link and the access link. In this case, the information processing device 10 may calculate the degree of interference according to a radio signal from the user terminal 30 and a pattern of a directional beam transmitted from each base station 20. Then, when the information processing device 10 permits connection of the access link, it may cause the user terminal 30 to transmit uplink data of the access link to the base station 20 by SDM or FDM to the backhaul link in one time slot.

[0089] A more specific processing example will be described below with reference to FIG. 14. The IAB node preferentially connects backhaul links with the IAB donor or IAB node of the upper station and the IAB node of the lower station. The resources of the backhaul link with the upper station are allocated by the upper station. The resources used for the backhaul link with the lower station are allocated to the lower station by the IAB node. Each IAB node stores the positions of multiple upper stations and IAB nodes of the lower station. Each IAB node can determine the beam pattern (e.g., the beam traveling direction, etc.) when multiple IAB nodes of the upper stations and lower stations transmit directional beams by testing at the time of installing the base station or by learning during operation. In this case, each IAB node uses a two-dimensional (2D) antenna arrangement, and three-dimensional (3D) directional beam control is used to control the elevation angle (Elevation) in addition to the phase angle (Azimuth).

[0090] In step S101, the information processing device 10 acquires from the IAB nodes the reception power and reception beam pattern of a radio signal from the uplink user terminal 30, and the reception beam pattern when the IAB nodes of multiple higher-level and lower-level stations transmit directional beams. Here, the radio signal may be, for example, a scheduling request signal, a sounding reference signal (SRS), or the like.

[0091] Next, the information processing device 10 calculates the interference power (an example of "interference degree") that the access link causes to the backhaul link (step S102). Here, the information processing device 10 may calculate the correlation of each reception beam acquired in step S101. Then, the information processing device 10 may calculate the interference power based on the correlation of each reception beam and the reception power of the wireless signal from the user terminal 30.

[0092] Next, the information processing device 10 calculates the realized throughput of the backhaul link according to the interference power that the access link gives to the backhaul link (step S103). Then, the information processing device 10 allows the connection of the access link in one of the following modes according to the reduction amount (deterioration amount) of the realized throughput of the backhaul link when the user terminal 30 requests a connection on the uplink of the access link. The information processing device 10 first determines whether the realized throughput is higher than the first target throughput (step S104). If the realized throughput is higher than the first target throughput (YES in step S104), the information processing device 10 multiplexes the uplink of the access link with the backhaul link by SDM (step S105), and ends the process. Here, the information processing device 10 performs connection of the access link, i.e., allocation of resources to the uplink of the access link. Then, the information processing device 10 causes the IAB node to transmit resource allocation information (grant) to the user terminal 30. This is the case, for example, when the access link is orthogonalized with the backhaul link by beamforming and SDM.

[0093] On the other hand, if the realized throughput is not higher than the first target throughput (NO in step S104), the information processing device 10 judges whether the realized throughput is higher than a second target throughput that is lower than the first target throughput (step S106). If the realized throughput is higher than the second target throughput (YES in step S106), the information processing device 10 multiplexes the uplink of the access link with the backhaul link by SDM (step S107) and ends the process. Here, the information processing device 10 may determine various parameters including the transmission power, waveform, modulation method, etc. of the user terminal 30 based on, for example, information acquired by the acquisition unit 11. In this case, the information processing device 10 may determine various parameters based on, for example, the distance between the IAB node and the user terminal 30, an estimated value of phase noise, and PAPR, etc. In this case, the information processing device 10 may calculate, for example, a reduction amount of the transmission power of the user terminal 30 that can realize the realized throughput of the first target throughput. Then, the information processing device 10 may notify the determined various parameters from the IAB node to the user terminal 30 via a downlink control channel. This makes it possible to realize the highest practical throughput in the uplink of the access link of the user terminal 30, for example.

[0094] On the other hand, if the realized throughput is not higher than the second target throughput (NO in step S106), the information processing device 10 determines whether the throughput of the backhaul link can be reduced to a third target throughput lower than the second target throughput (step S108). If the throughput can be reduced to the third target throughput (YES in step S108), the information processing device 10 reduces the throughput of the backhaul link, FDM-multiplexes the uplink of the access link into the same slot as the backhaul link (step S109), and ends the process. Here, the information processing device 10 may determine various parameters including the transmission power, waveform, modulation method, and transmission timing of the transmission signal from the user terminal 30 of the user terminal 30 based on, for example, information acquired by the acquisition unit 11. In this case, the information processing device 10 may determine various parameters based on, for example, the distance between the IAB node and the user terminal 30, the estimated value of the phase noise, the PAPR, and the like. Then, the information processing device 10 may cause the IAB node to notify the user terminal 30 of the determined various parameters through a downlink control channel. This makes it possible to realize, for example, the highest practical throughput in the access link of the user terminal 30.

[0095] On the other hand, if the throughput of the backhaul link cannot be reduced to the third target throughput (NO in step S108), the information processing device 10 causes the IAB node to reject (does not allow) the connection of the access link by the user terminal 30 (step S110), and ends the process. Here, the information processing device 10 may assign a time slot different from that of the backhaul link to the uplink of the access link. This causes the uplink of the access link to be TDM-multiplexed with the backhaul link.

[0096] Next, an example of resource allocation processing of the downlink of the access link when the backhaul link and the access link use the same frequency spectrum and the IAB node (for example, the small cell base station 20B, 20C) performs multi-hop communication will be described with reference to Fig. 15. Fig. 15 is a flowchart showing an example of resource allocation processing of the downlink of the access link according to the embodiment.

[0097] As shown in Fig. 15, when the backhaul link and the access link use the same frequency spectrum and multiple small cell base stations perform multi-hop communication, the information processing device 10 may calculate the degree of interference between the backhaul link and the access link. In this case, the information processing device 10 may calculate the degree of interference based on the pattern of a directional beam transmitted from each base station 20, for example. Then, the information processing device 10 may determine whether or not to permit connection of the access link of the user terminal 30 based on the calculated degree of interference.

[0098] Then, when the information processing device 10 permits the user terminal 30 to connect an access link, the information processing device 10 may cause the base station 20 to transmit uplink data of the access link to the user terminal 30 using SDM or FDM on a backhaul link in one time slot.

[0099] A more specific processing example will be described below with reference to Fig. 15. As described above, the IAB node preferentially connects backhaul links with the IAB donor or IAB node of the upper station and the IAB node of the lower station. Transmission to the IAB node of the upper station and the IAB node of the lower station may be performed in the same slot or in different slots.

[0100] In step S201, the information processing device 10 acquires the directional beam patterns and transmission powers of the backhaul link and the access link. Next, the information processing device 10 calculates the interference power between beams that the access link gives to the backhaul link based on the information acquired in step S201 (step S202). Next, the information processing device 10 calculates the realized throughput of the backhaul link according to the interference power that the access link gives to the backhaul link (step S203).

[0101] Then, the information processing device 10 allows the connection of the access link in any of the following modes depending on the reduction (deterioration) of the realized throughput of the backhaul link when the access link is connected to the user terminal 30. The information processing device 10 first determines whether the realized throughput is higher than the first target throughput (step S204). If the realized throughput is higher than the first target throughput (YES in step S204), the information processing device 10 multiplexes the downlink of the access link with the backhaul link by SDM (step S205) and ends the process. Here, the information processing device 10 transmits the downlink of the access link, i.e., allocates resources to the access link to the user terminal 30. This is, for example, a situation in which the access link has been orthogonalized with the backhaul link by SDM through beamforming.

[0102] On the other hand, if the realized throughput is not higher than the first target throughput (NO in step S204), the information processing device 10 judges whether the realized throughput is higher than a second target throughput lower than the first target throughput (step S206). If the realized throughput is higher than the second target throughput (YES in step S206), the information processing device 10 multiplexes the downlink of the access link with the backhaul link by SDM (step S207) and ends the process. Here, the information processing device 10 may determine various parameters including the transmission power, waveform, modulation method, etc. from the IAB node to the user terminal 30 based on, for example, information acquired by the acquisition unit 11. In this case, the information processing device 10 may determine various parameters based on, for example, the distance between the IAB node and the user terminal 30, the PAPR, the estimated value of the phase noise, the PAPR, etc. In this case, the information processing device 10 may calculate, for example, the transmission power from the IAB node to the user terminal 30 that can realize the realized throughput of the first target throughput. Then, the information processing device 10 may notify the IAB node of the determined various parameters and have the IAB node set them. This makes it possible to realize the highest practical throughput in the downlink of the access link, for example.

[0103] On the other hand, if the realized throughput is not higher than the second target throughput (NO in step S206), the information processing device 10 determines whether the throughput of the backhaul link can be reduced to a third target throughput lower than the second target throughput (step S208). If the throughput can be reduced to the third target throughput (YES in step S208), the information processing device 10 reduces the throughput of the backhaul link, FDM-multiplexes the access link and the backhaul link in the same slot (step S209), and ends the process. Here, the information processing device 10 may determine various parameters including the transmission power from the IAB node to the user terminal 30, the waveform, the modulation method, the transmission timing of the transmission signal from the user terminal 30, etc., based on information acquired by the acquisition unit 11, for example. In this case, the information processing device 10 may determine various parameters based on, for example, the distance between the IAB node and the user terminal 30, the estimated value of the phase noise, the PAPR, etc. Then, the information processing device 10 may notify the determined various parameters from the IAB node to the user terminal 30 via a downlink control channel. This makes it possible to realize the highest practical throughput in the downlink of the access link of the user terminal 30, for example.

[0104] On the other hand, if the throughput of the backhaul link cannot be reduced to the third target throughput (NO in step S208), the information processing device 10 does not transmit the downlink of the access link by the user terminal 30 to the IAB node (step S210), and ends the process. Here, the information processing device 10 may assign a time slot different from that of the backhaul link to the downlink of the access link. This causes the downlink of the access link to be TDM-multiplexed with the backhaul link.

[0105] Modifications of the embodiment of the present disclosure will be described below. Each of the following modifications may be implemented in appropriate combination with the embodiment of the present disclosure. <Variation 1> The information processing device 10 may be a device contained in one housing, but the information processing device 10 of the present disclosure is not limited to this. Each unit of the information processing device 10 may be realized by cloud computing configured by one or more computers, for example. The information processing device 10 may also be a server or edge server that realizes network virtualization (Network Functions Virtualization, NFV). At least a part of the processing of each unit of the information processing device 10 may be executed by a base station 20 or a user terminal 30. Such information processing devices 10 are also included in examples of the "information processing device" of the present disclosure.

[0106] <Variation 2> FIG. 16 is a diagram showing an example of a configuration in which the information processing device 10 is realized by a computer and a program. In the example of FIG. 16, the information processing device 10 (computer 100) includes a processor 101, a memory 102, and a communication interface 103. These units may be connected by a bus or the like. The memory 102 stores at least a part of a program 104. The communication interface 103 includes an interface required for communication with other network elements. In the case of the base station 20, the communication interface 103 includes, for example, an interface for communication with a user terminal 30 via one or more antennas, an interface for communication between base stations, and an interface for communication with various servers on the core network side.

[0107] When the program 104 is executed by the processor 101, memory 102, etc. in cooperation, the computer 100 performs at least some processing of the embodiments of the present disclosure. The memory 102 may be of any type suitable for a local technology network. The memory 102 may be, as a non-limiting example, a non-transitory computer-readable storage medium. The memory 102 may also be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. Although only one memory 102 is shown in the computer 100, several physically different memory modules may be present in the computer 100. The processor 101 may be of any type. The processor 101 may include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture, as a non-limiting example. The computer 100 may have multiple processors, such as application-specific integrated circuit chips that are time-slaved to a clock that synchronizes the main processor.

[0108] The embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor or other computing device.

[0109] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions included in program modules, that execute on a target real or virtual processor device to perform the processes or methods of the present disclosure. Program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. The machine-executable instructions of the program modules may be executed in local or distributed devices. In a distributed device, the program modules may be located in both local and remote storage media.

[0110] The program codes for carrying out the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes are provided to a processor or controller of a general purpose computer, a special purpose computer, or other programmable data processing apparatus. When the program codes are executed by the processor or controller, the functions / operations in the flowcharts and / or the block diagrams they implement are performed. The program codes are executed entirely on the machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine, or entirely on a remote machine or server.

[0111] The program can be stored and provided to the computer using various types of non-transitory computer readable media. The non-transitory computer readable media includes various types of tangible recording media. Examples of the non-transitory computer readable media include magnetic recording media, magneto-optical recording media, optical disk media, semiconductor memory, and the like. The magnetic recording media include, for example, flexible disks, magnetic tapes, hard disk drives, and the like. The magneto-optical recording media include, for example, magneto-optical disks, and the like. The optical disk media include, for example, Blu-ray disks, CD (Compact Disc)-ROM (Read Only Memory), CD-R (Recordable), CD-RW (ReWritable), and the like. The semiconductor memory includes, for example, solid state drives, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory), and the like. The program may also be provided to the computer by various types of temporary computer readable media. Examples of the temporary computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire or an optical fiber, or via a wireless communication path.

[0112] The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit and scope of the present invention.

[0113] A part or all of the above-described embodiments can be described as, but is not limited to, the following supplementary notes. (Appendix 1) Information regarding wireless communication of a backhaul link between the first base station and the second base station; An acquisition means for acquiring information regarding wireless communication of an access link between the second base station and a user terminal; a control means for determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the information acquired by the acquisition means; a transmitting means for transmitting information indicating the first wireless communication method determined by the control means to at least one of the first base station and the second base station, and for transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal; An information processing device having the above configuration. (Appendix 2) The information related to the wireless communication of the backhaul link includes information indicating at least one of a frequency spectrum available for wireless communication of each of the first base station and the second base station, a size of each coverage area, a distance between each base station, a traffic distribution in each coverage area, a peak-to-average power ratio of a transmission signal, a phase noise, and a power delay profile. 2. An information processing device according to claim 1. (Appendix 3) The information related to the wireless communication of the access link includes information indicating at least one of a frequency spectrum available for wireless communication of the second base station, a size of each coverage area, a peak-to-average power ratio of a transmission signal, a phase noise, a power delay profile, and a moving speed of the user terminal. 3. The information processing device according to claim 1 or 2. (Appendix 4) The control means determines at least one of a physical channel multiplexing scheme, a set of coding rates for channel coding, and a set of signal space constellations for mapping bits after channel coding, for at least one of the backhaul link and the access link, based on the information acquired by the acquisition means. 4. The information processing device according to claim 1 . (Appendix 5) The control means determines at least one of a multiplexing method of a reference signal, a multiplexing method of a control signal, a symbol interval of a transmission signal, and a roll-off rate of a root raised cosine filter for at least one of the backhaul link and the access link based on the information acquired by the acquisition means. 5. An information processing device according to any one of claims 1 to 4. (Appendix 6) The control means When the backhaul link and the access link use the same frequency spectrum and a plurality of small cell base stations perform multi-hop communication, determining whether or not to permit connection of the access link based on a degree of interference between the backhaul link and the access link according to a radio signal from the user terminal and a pattern of a directional beam transmitted from each base station; When the connection of the access link is permitted, uplink data of the access link is transmitted from the user terminal forming the access link to a base station by spatial division multiplexing or frequency division multiplexing to the backhaul link in one time slot. 6. An information processing device according to any one of claims 1 to 5. (Appendix 7) The control means When the backhaul link and the access link use the same frequency spectrum and a plurality of small cell base stations perform multi-hop communication, determining whether or not to permit connection of the access link based on a degree of interference between the backhaul link and the access link according to a pattern of a directional beam transmitted from each small cell base station; When the connection of the access link is permitted, uplink data of the access link is transmitted from the base station forming the access link to the user terminal by spatial division multiplexing or frequency division multiplexing to the backhaul link in one time slot. 7. An information processing device according to any one of claims 1 to 6. (Appendix 8) Obtaining first information regarding wireless communication of a backhaul link between a first base station and a second base station; acquiring second information regarding wireless communication of an access link between the second base station and a user terminal; determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the first information and the second information; transmitting information indicating the first wireless communication method to at least one of the first base station and the second base station; transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal; Information processing methods. (Appendix 9) The first information regarding the wireless communication of the backhaul link includes information indicating at least one of a frequency spectrum available for wireless communication of each of the first base station and the second base station, a size of a coverage area, a distance between base stations, a traffic distribution in the coverage area, a peak-to-average power ratio of a transmission signal, a phase noise, and a power delay profile. 10. An information processing method as described in Appendix 8. (Appendix 10) The second information regarding the wireless communication of the access link includes information indicating at least one of a frequency spectrum available for wireless communication of the second base station, a size of a coverage area, a peak-to-average power ratio of a transmission signal, a phase noise, a power delay profile, and a moving speed of the user terminal. 10. An information processing method according to claim 8 or 9. (Appendix 11) determining at least one of a physical channel multiplexing scheme, a set of coding rates for channel coding, and a set of signal space constellations for mapping bits after channel coding, for at least one of the backhaul link and the access link based on the first information and the second information; 11. An information processing method according to any one of appendix 8 to 10. (Appendix 12) determining at least one of a multiplexing method of a reference signal, a multiplexing method of a control signal, a symbol interval of a transmission signal, and a roll-off rate of a root raised cosine filter for at least one of the backhaul link and the access link based on the first information and the second information; 12. An information processing method according to any one of appendix 8 to 11. (Appendix 13) Obtaining first information regarding wireless communication of a backhaul link between a first base station and a second base station; obtaining second information regarding wireless communication of an access link between the second base station and a user terminal; determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the first information and the second information; transmitting information indicating the first wireless communication method to at least one of the first base station and the second base station; transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal; A non-transitory computer-readable medium storing a program for causing an information processing device to execute the above. (Appendix 14) A first base station, a second base station, and a user terminal, Information regarding wireless communication of a backhaul link between the first base station and the second base station; An acquisition means for acquiring information regarding wireless communication of an access link between the second base station and a user terminal; a control means for determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the information acquired by the acquisition means; a transmitting means for transmitting information indicating the first wireless communication method determined by the control means to at least one of the first base station and the second base station, and for transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal; A wireless communication system having the following: (Appendix 15) The information related to the wireless communication of the backhaul link includes information indicating at least one of a frequency spectrum available for wireless communication of each of the first base station and the second base station, a size of each coverage area, a distance between each base station, a traffic distribution in each coverage area, a peak-to-average power ratio of a transmission signal, a phase noise, and a power delay profile. 15. The wireless communication system of claim 14.

[0114] This application claims priority based on Japanese Patent Application No. 2021-100001, filed on June 16, 2021, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0115] 1. Wireless communication systems 10. Information processing device 11 Acquisition Department 12 Control section 13 Transmitter 20 base station 30 User terminal

Claims

1. Information regarding wireless communication of a backhaul link between a first base station and a second base station; An acquisition means for acquiring information regarding wireless communication of an access link between the second base station and a user terminal; a control means for determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the information acquired by the acquisition means; a transmitting means for transmitting information indicating the first wireless communication method determined by the control means to at least one of the first base station and the second base station, and for transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal; having The control means determines at least one of a multiplexing method of a reference signal, a multiplexing method of a control signal, a symbol interval of a transmission signal, and a roll-off rate of a root raised cosine filter for at least one of the backhaul link and the access link based on the information acquired by the acquisition means. Information processing device.

2. Information regarding wireless communication of a backhaul link between a first base station and a second base station; An acquisition means for acquiring information regarding wireless communication of an access link between the second base station and a user terminal; a control means for determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the information acquired by the acquisition means; a transmitting means for transmitting information indicating the first wireless communication method determined by the control means to at least one of the first base station and the second base station, and for transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal; having The control means When the backhaul link and the access link use the same frequency spectrum and a plurality of small cell base stations perform multi-hop communication, determining whether or not to permit connection of the access link based on a degree of interference between the backhaul link and the access link according to a radio signal from the user terminal and a pattern of a directional beam transmitted from each base station; When the connection of the access link is permitted, uplink data of the access link is transmitted from the user terminal forming the access link to a base station by spatial division multiplexing or frequency division multiplexing to the backhaul link in one time slot. Information processing device.

3. Information regarding wireless communication of a backhaul link between a first base station and a second base station; An acquisition means for acquiring information regarding wireless communication of an access link between the second base station and a user terminal; a control means for determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the information acquired by the acquisition means; a transmitting means for transmitting information indicating the first wireless communication method determined by the control means to at least one of the first base station and the second base station, and for transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal; having The control means When the backhaul link and the access link use the same frequency spectrum and a plurality of small cell base stations perform multi-hop communication, determining whether or not to permit connection of the access link based on a degree of interference between the backhaul link and the access link according to a pattern of a directional beam transmitted from each small cell base station; When the connection of the access link is permitted, uplink data of the access link is transmitted from the base station forming the access link to the user terminal by spatial division multiplexing or frequency division multiplexing to the backhaul link in one time slot. Information processing device.

4. The information related to the wireless communication of the backhaul link includes information indicating at least one of a frequency spectrum available for wireless communication of each of the first base station and the second base station, a size of each coverage area, a distance between each base station, a traffic distribution in each coverage area, a peak-to-average power ratio of a transmission signal, a phase noise, and a power delay profile. The information processing device according to claim 1 .

5. The information related to the wireless communication of the access link includes information indicating at least one of a frequency spectrum available for wireless communication of the second base station, a size of each coverage area, a peak-to-average power ratio of a transmission signal, a phase noise, a power delay profile, and a moving speed of the user terminal. The information processing device according to claim 1 .

6. The control means determines at least one of a physical channel multiplexing scheme, a set of coding rates for channel coding, and a set of signal space constellations for mapping bits after channel coding, for at least one of the backhaul link and the access link, based on the information acquired by the acquisition means. The information processing device according to claim 1 .

7. Acquiring first information regarding wireless communication of a backhaul link between a first base station and a second base station; Obtaining second information related to wireless communication of an access link between the second base station and a user terminal; determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the first information and the second information; transmitting information indicating the first wireless communication method to at least one of the first base station and the second base station; Transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal; In the process of determining, determining at least one of a multiplexing method of a reference signal, a multiplexing method of a control signal, a symbol interval of a transmission signal, and a roll-off rate of a root raised cosine filter for at least one of the backhaul link and the access link based on the first information and the second information; Information processing methods.

8. Acquiring first information regarding wireless communication of a backhaul link between a first base station and a second base station; Obtaining second information related to wireless communication of an access link between the second base station and a user terminal; determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the first information and the second information; transmitting information indicating the first wireless communication method to at least one of the first base station and the second base station; Transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal; In the process of determining, When the backhaul link and the access link use the same frequency spectrum and a plurality of small cell base stations perform multi-hop communication, determining whether or not to permit connection of the access link based on a degree of interference between the backhaul link and the access link according to a radio signal from the user terminal and a pattern of a directional beam transmitted from each base station; When the connection of the access link is permitted, uplink data of the access link is transmitted from the user terminal forming the access link to a base station by spatial division multiplexing or frequency division multiplexing to the backhaul link in one time slot. Information processing methods.

9. Acquiring first information regarding wireless communication of a backhaul link between a first base station and a second base station; Obtaining second information related to wireless communication of an access link between the second base station and a user terminal; determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the first information and the second information; transmitting information indicating the first wireless communication method to at least one of the first base station and the second base station; Transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal; In the process of determining, When the backhaul link and the access link use the same frequency spectrum and a plurality of small cell base stations perform multi-hop communication, determining whether or not to permit connection of the access link based on a degree of interference between the backhaul link and the access link according to a pattern of a directional beam transmitted from each small cell base station; When the connection of the access link is permitted, uplink data of the access link is transmitted from the base station forming the access link to the user terminal by spatial division multiplexing or frequency division multiplexing to the backhaul link in one time slot. Information processing methods.

10. The first information regarding the wireless communication of the backhaul link includes information indicating at least one of a frequency spectrum available for wireless communication of each of the first base station and the second base station, a size of a coverage area, a distance between base stations, a traffic distribution in the coverage area, a peak-to-average power ratio of a transmission signal, a phase noise, and a power delay profile. The information processing method according to any one of claims 7 to 9.

11. The second information regarding the wireless communication of the access link includes information indicating at least one of a frequency spectrum available for wireless communication of the second base station, a size of a coverage area, a peak-to-average power ratio of a transmission signal, a phase noise, a power delay profile, and a moving speed of the user terminal. The information processing method according to any one of claims 7 to 9.

12. determining at least one of a physical channel multiplexing scheme, a set of coding rates for channel coding, and a set of signal space constellations for mapping bits after channel coding, for at least one of the backhaul link and the access link based on the first information and the second information; The information processing method according to any one of claims 7 to 9.

13. A process of acquiring first information regarding wireless communication of a backhaul link between a first base station and a second base station; acquiring second information related to wireless communication of an access link between the second base station and a user terminal; determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the first information and the second information; transmitting information indicating the first wireless communication method to at least one of the first base station and the second base station; transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal; causing an information processing device to execute the above; In the process of determining, determining at least one of a multiplexing method of a reference signal, a multiplexing method of a control signal, a symbol interval of a transmission signal, and a roll-off rate of a root raised cosine filter for at least one of the backhaul link and the access link based on the first information and the second information; program.

14. A first base station, a second base station, and a user terminal, Information regarding wireless communication of a backhaul link between the first base station and the second base station; An acquisition means for acquiring information regarding wireless communication of an access link between the second base station and a user terminal; a control means for determining a first wireless communication method for the backhaul link and a second wireless communication method for the access link based on the information acquired by the acquisition means; a transmitting means for transmitting information indicating the first wireless communication method determined by the control means to at least one of the first base station and the second base station, and for transmitting information indicating the second wireless communication method to at least one of the second base station and the user terminal; having The control means determines at least one of a multiplexing method of a reference signal, a multiplexing method of a control signal, a symbol interval of a transmission signal, and a roll-off rate of a root raised cosine filter for at least one of the backhaul link and the access link based on the information acquired by the acquisition means. Wireless communication system.

15. The information related to the wireless communication of the backhaul link includes information indicating at least one of a frequency spectrum available for wireless communication of each of the first base station and the second base station, a size of each coverage area, a distance between each base station, a traffic distribution in each coverage area, a peak-to-average power ratio of a transmission signal, a phase noise, and a power delay profile.

15. The wireless communication system of claim 14.

16. The user terminal Connecting to a first base station via an access link; receiving information indicating a wireless communication method of the access link, the information including at least one of a multiplexing method of a reference signal, a multiplexing method of a control signal, a symbol interval of a transmission signal, and a roll-off rate of a root raised cosine filter, for at least one of the backhaul link and the access link, the multiplexing method being determined based on first information regarding wireless communication between the first base station and a second base station connected via a backhaul link and second information regarding wireless communication between the first base station and a user terminal connected via the access link; method.

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