Electronic devices, systems, control methods, and programs

Abstract

The present invention provides electronic devices, systems, control methods, and programs that enable wireless communication using massive MIMO, simplifying hardware configuration, reducing processing costs, and providing good communication quality. [Solution] The electronic device comprises multiple subarrays, each containing multiple antenna elements, and performs massive MIMO communication with multiple other electronic devices. The electronic device performs beamforming by weight control of the signal phase such that a beam formed by one of the multiple subarrays points towards a desired device among the multiple other electronic devices, and a null formed by one of the subarrays points towards devices other than the desired device among the multiple other electronic devices.

Description

[Technical Field]

[0001] This disclosure relates to electronic devices, systems, control methods, and programs. [Background technology]

[0002] MIMO (multiple-input and multiple-output), which uses multiple antennas on both the transmitter and receiver, is attracting attention as a technology to improve the communication quality of wireless communication. MIMO plays an important role in recent wireless communication standards such as IEEE 802.11 wireless LAN (Wi-Fi), 3GPP Long Term Evolution (4G-LTE), and 5G-NR. Single-user MIMO (SU-MIMO) is known as MIMO transmission performed on the same frequency at the same time for a single user. Multi-user MIMO (MU-MIMO) is known as MIMO transmission performed on the same frequency at the same time for multiple users. Furthermore, research is progressing on massive MIMO, a technology that improves line gain and eliminates unwanted interference waves by significantly increasing the number of transmitting and receiving antennas (for example, up to 128).

[0003] The challenge in realizing massive MIMO is the increased power consumption and equipment cost due to connecting numerous antenna elements with ADCs (Analog to digital converters) and DACs (Digital to analog converters). Therefore, as described in Non-Patent Document 1, hybrid beamforming methods that combine analog beamforming and digital beamforming, with the former performing beamforming and the latter performing spatial multiplexing, are being widely considered. Furthermore, as described in Non-Patent Document 2, a hybrid beamforming configuration is being considered in which numerous antenna elements are divided into several sub-arrays, and one terminal (mobile communication terminal) UE (User Equipment) is connected to each sub-array. [Advanced Technology Documents]

Non-licensed literature

[0004]

Non-licensed literature 1

Non-licensed Document 4

[0005] When achieving high-speed and / or stable wireless communication using massive MIMO, it is desirable to reduce processing costs with a simple hardware configuration.

[0006] The purpose of this disclosure is to provide electronic devices, systems, control methods, and programs that can simplify hardware configurations, reduce processing costs, and provide good communication quality when realizing wireless communication using massive MIMO. [Means for solving the problem]

[0007] An electronic device according to one embodiment (first electronic device) is: It has multiple sub-arrays, each containing multiple antenna elements, and performs massive MIMO communication with multiple other electronic devices (second electronic devices). Beamforming is performed by weight control of the signal phase such that the beam formed by one of the plurality of subarrays is directed toward the desired device among the plurality of other electronic devices (second electronic devices), and the null formed by that one subarray is directed toward the devices other than the desired device among the plurality of other electronic devices (second electronic devices).

[0008] A system according to one embodiment includes an electronic device (first electronic device) and a plurality of other electronic devices (second electronic devices). In the system, the electronic device (first electronic device) includes a plurality of sub-arrays each including a plurality of antenna elements, and performs massive MIMO communication with the plurality of other electronic devices (second electronic devices). A beam formed by one of the plurality of sub-arrays is directed toward a desired one of the plurality of other electronic devices (second electronic devices), and a null formed by the one sub-array is directed toward a device other than the desired device among the plurality of other electronic devices (second electronic devices). Beamforming is performed by weight control with respect to the phase of the signal.

[0009] A control method according to an embodiment is a control method for an electronic device (first electronic device) including a plurality of sub-arrays each including a plurality of antenna elements and performing massive MIMO communication with a plurality of other electronic devices (second electronic devices), including the step of performing beamforming by weight control with respect to the phase of the signal so that a beam formed by one of the plurality of sub-arrays is directed toward a desired one of the plurality of other electronic devices (second electronic devices), and a null formed by the one sub-array is directed toward a device other than the desired device among the plurality of other electronic devices (second electronic devices).

[0010] A program according to an embodiment causes an electronic device (first electronic device) including a plurality of sub-arrays each including a plurality of antenna elements and performing massive MIMO communication with a plurality of other electronic devices (second electronic devices) to execute the step of performing beamforming by weight control with respect to the phase of the signal so that a beam formed by one of the plurality of sub-arrays is directed toward a desired one of the plurality of other electronic devices (second electronic devices), and a null formed by the one sub-array is directed toward a device other than the desired device among the plurality of other electronic devices (second electronic devices).

Advantages of the Invention

[0011] According to one embodiment, when realizing wireless communication by massive MIMO, it is possible to provide an electronic device, a system, a control method, and a program that can simplify the hardware configuration, reduce the processing cost, and provide good communication quality.

Brief Description of the Drawings

[0012] [Figure 1] It is a diagram showing an example of a system including a first electronic device and a second electronic device according to one embodiment. [Figure 2] It is a block diagram schematically showing a functional configuration of a first electronic device according to one embodiment. [Figure 3] It is a block diagram schematically showing a functional configuration of a first electronic device according to one embodiment. [Figure 4] It is a diagram showing the transmission period of SSB (Synchronization Signal Block) defined in 3GPP TS38.213. [Figure 5] It is a flowchart showing an example of an operation by a first electronic device according to one embodiment. [Figure 6] It is a diagram showing an example of null extension on the frequency axis by a first electronic device according to one embodiment. [Figure 7] It is a diagram showing an example of null extension on the frequency axis by a first electronic device according to one embodiment. [Figure 8] It is a diagram showing an example of simulating null extension on the frequency axis by a first electronic device according to one embodiment.

Modes for Carrying Out the Invention

[0013] In this disclosure, “electronic device” may mean an electric-powered device. “System” may mean a device or group of devices including an electric-powered device. “User” may mean a person (typically a human) using the system and / or electronic device according to one embodiment. By using the system and / or electronic device according to one embodiment, it is possible to simplify the hardware configuration, reduce processing costs, and provide good communication quality when implementing wireless communication with massive MIMO.

[0014] <System including the first electronic device 1 according to one embodiment> First, we will describe the overall system configuration of one embodiment.

[0015] Figure 1 is a diagram showing an example of a system including electronic equipment according to one embodiment. Figure 1 is a diagram showing the configuration of a system including electronic equipment according to one embodiment, mainly from a functional standpoint.

[0016] A system including electronic equipment according to one embodiment may be configured based on a concept at least partially similar to that of a general MIMO system. As shown in Figure 1, a system according to one embodiment may include a first electronic device 1 and a second electronic device 2.

[0017] The first electronic device 1 may be, for example, a base station (mobile communication base station) gNB (gNodeB) compatible with 5G wireless communication. The first electronic device 1 may have at least two sub-arrays 10 (antenna arrays). The first electronic device 1 shown in Figure 1 has a plurality of sub-arrays 10, namely sub-array 10A, sub-array 10B, ..., sub-array 10N. Hereinafter, when sub-arrays such as sub-array 10A, sub-array 10B, ..., sub-array 10N are not particularly distinguished, they may simply be referred to as "sub-array 10". The first electronic device 1 according to one embodiment may have any plurality of sub-arrays 10. The first electronic device 1 according to one embodiment may not include some of the functional parts shown in Figure 1, or it may include functional parts other than those shown in Figure 1. A more detailed configuration of the first electronic device 1 will be described later.

[0018] Each sub-array 10 may be equipped with multiple antenna elements (e.g., patches). Figure 1 schematically shows how each sub-array 10 is arranged on a two-dimensional plane with multiple small antenna elements. A single sub-array 10 may have multiple antenna elements arranged in any direction, such as the up-and-down (vertical) direction and the left-and-right (horizontal) direction. The first electronic device 1 may also have multiple sub-arrays 10 arranged in any direction, such as the up-and-down (vertical) direction and the left-and-right (horizontal) direction.

[0019] The second electronic device 2 may be, for example, a terminal (mobile communication terminal) UE (User Equipment) compatible with 5G wireless communication. The system according to one embodiment may be configured to include at least two second electronic devices 2. The system shown in Figure 1 includes a plurality of second electronic devices 2, namely second electronic device 2A, second electronic device 2B, ..., second electronic device 2N. Hereinafter, when second electronic devices such as second electronic device 2A, second electronic device 2B, ..., second electronic device 2N are not particularly distinguished, they may simply be referred to as "second electronic device 2". The system according to one embodiment may include any plurality of second electronic devices 2. Since the second electronic device 2 may be based on the same concept as a UE compatible with a MIMO system, a more detailed explanation is omitted.

[0020] In Figure 1, the sub-array 10A of the first electronic device 1 may be configured to connect to the second electronic device 2A. The sub-array 10B of the first electronic device 1 may be configured to connect to the second electronic device 2B. The sub-array 10N of the first electronic device 1 may be configured to connect to the second electronic device 2N.

[0021] The signal transmitted from the first electronic device 1 to the second electronic device 2 may undergo signal processing as shown from top to bottom in the first electronic device 1 shown in Figure 1. That is, first, layer mapping of the transmitted signal is performed in the first electronic device 1. Here, a layer is the number of signal streams transmitted spatially superimposed on the same time and frequency, i.e., on the same radio resource. Layer mapping may be an operation that assigns modulated data to each of m layers. Subsequently, the layer-mapped signal may be supplied to the respective analog beam control function corresponding to each subarray 10, with each subarray 10 having m layers (m layers / subarray). Next, the layer-mapped signal is subjected to analog precoding by the phase control function corresponding to each of the multiple subarrays 10. Subsequently, the phase-controlled signal may be transmitted, for example, from the multiple corresponding subarrays 10A to subarrays 10N to the respective second electronic devices 2A to second electronic devices 2N.

[0022] As shown in Figure 1, the single-user MIMO signals transmitted from the multiple sub-arrays 10 of the first electronic device 1 to the corresponding second electronic device 2 may each have up to m layers.

[0023] In fifth-generation mobile communication systems (5G), massive MIMO, which uses a large number of antenna elements to perform spatial multiplexing with multiple UEs, is being widely considered to improve cell throughput. Implementing massive MIMO requires connecting a large number of antenna elements to corresponding ADCs (Analog to Digital converters) and DACs (Digital to Analog converters). Therefore, massive MIMO tends to increase power consumption and equipment costs.

[0024] Hereinafter, the system according to one embodiment will be described as including a base station (first electronic device 1) that performs beamforming using a sub-array antenna (sub-array 10) as shown in Figure 1. Furthermore, the system according to one embodiment may also include a terminal (second electronic device 2) as shown in Figure 1.

[0025] Next, I will explain the challenges of conventional massive MIMO.

[0026] Normally, in downlink, spatial multiplexing for MIMO is performed by precoding in the baseband digital signal processing unit. However, in the high-frequency bands above FR2 (24.25 GHz), which are used for 5G, the following implementation challenges arise.

[0027] In the O-RAN (Open Radio Access Network) standard, functions are divided into two layers, such as an upper layer and a lower layer, and the connection between these two functions is defined as a Front Haul (FH) interface. This FH interface, which divides the physical layer into two, is called Split7-2x. When functions are divided by Split7-2x according to the O-RAN standard, the delay time from when the base station receives the uplink SRS (Sounding Reference Signal) to when the precoding weight is multiplied by the transmitted data (downlink) increases. As a result, it is expected that the degradation of the signal-to-interference-plus-noise ratio (SINR), which is the communication quality in response to channel fluctuations caused by changes in the radio environment, will become more pronounced.

[0028] To address the aforementioned challenges, the following describes an electronic device that performs beamforming using a subarray, which has the following characteristics.

[0029] (1) For weight control of the array antenna, only control of the signal phase is performed. (2) A single sub-array forms a single directional pattern (due to (1)). (3) One terminal (UE) is connected to one subarray. (4) One subarray forms a beam toward the desired terminal and directs nulls toward terminals other than the desired terminal. Due to the features described above, the cost increase caused by control devices in the high-frequency band above FR2 is eliminated.

[0030] In an array antenna, the characteristics that show the reception / transmission intensity for each radiation direction are called directional characteristics. Here, the area around the extreme values ​​with high radiation intensity is called a lobe, and the area with the highest radiation intensity is called the main lobe. Also, the spatial point between lobes where the radiation intensity sharply attenuates is called a null. In one embodiment, the main lobe is directed towards the desired terminal UE (second electronic device 2), and the null is directed towards the interfering UE (a terminal UE other than the desired terminal UE (second electronic device 2)). In this way, interference from other terminal UEs can be suppressed and the SINR can be maximized.

[0031] <Configuration of the first electronic device according to one embodiment>

[0032] Figure 2 is a block diagram showing the functional configuration of the first electronic device 1 according to one embodiment. Figure 2 is a diagram showing the basic configuration of the first electronic device 1 according to one embodiment. Figure 2 is a diagram illustrating the first electronic device 1 according to one embodiment, mainly as a hardware and / or software configuration.

[0033] As shown in Figure 2, the first electronic device 1 according to one embodiment may include a subarray 10, a channel estimation unit 22, a weight calculation unit 24, and a precoder 34. The first electronic device 1 shown in Figure 2 includes a plurality of precoders 34, namely precoder 34A, precoder 34B, ..., precoder 34N. Hereinafter, when precoders such as precoder 34A, precoder 34B, ..., precoder 34N are not particularly distinguished, they may simply be referred to as "precoder 34". The first electronic device 1 according to one embodiment may include precoders 34 corresponding to any plurality of subarrays 10. The first electronic device 1 according to one embodiment may not include some of the functional units shown in Figure 2, and may include functional units other than those shown in Figure 2.

[0034] Subarray 10 may be the same as the one described in Figure 1. In particular, subarray 10N may be the Nth subarray equipped with an array antenna. The channel estimation unit 22 has the function of estimating channel information for use in calculating the weights of precoding by the precoder 34. Channel estimation by the channel estimation unit 22 will be described further later. The weight calculation unit 24 has the function of calculating the weights to be set for each subarray 10 based on the channel information estimated by the channel estimation unit 22. Control of the weights by the weight calculation unit 24 will be described further later. The precoder 34 has the function of multiplying the signals input to each subarray 10 by analog weights.

[0035] Furthermore, a 5G base station may, in general terms, consist of a radio unit (RU) which comprises the base station's antenna and radio section, a distributed unit (DU) also called a slave station, and a central unit (CU) also called a master station or aggregation station. The RU has the function of sending and receiving radio waves with the UE (User Equipment), which is a terminal (mobile device) for communication, and communicating with the DU. The DU mainly has the function of modulating and demodulating signals and retransmitting lost signals. The CU mainly has the function of controlling multiple DUs and controlling the RRC (Radio Resource Control), which is a communication protocol between the UE and the base station.

[0036] One embodiment of the first electronic device 1 may include an architecture based on the standard specifications defined by the O-RAN (Open Radio Access Network) Alliance. The O-RAN Alliance is an industry association established by agreement of several companies. For example, one embodiment of the first electronic device 1 may implement the above-mentioned RU, DU, and CU as an architecture based on the O-RAN specifications. The following description will focus on the case where the architecture is implemented based on the O-RAN specifications, but the contents of this disclosure are not limited thereto. The above-mentioned functions may be realized by implementation methods other than the O-RAN specifications. Furthermore, in the contents of this disclosure, it is not essential to physically or logically separate the functions of the base station (first electronic device 1) into RU and DU.

[0037] Figure 3 shows an example of the configuration of the first electronic device 1', which is implemented as an architecture based on the O-RAN specification, based on the first electronic device 1 according to one embodiment shown in Figure 2. The first electronic device 1' shown in Figure 3 may implement the architecture based on the O-RAN specification as hardware and / or software. Figure 3 shows an example of implementation assuming functional division by Split7-2x.

[0038] As shown in Figure 3, the first electronic device 1' according to one embodiment may include a radio unit O-RU (O-RAN Radio Unit) 30 as a component of the O-RAN network that performs the function of a radio access node. The first electronic device 1' may also include a distributed unit O-DU (O-RAN distributed Unit) 20 as a component that performs radio access functions such as data modulation, demodulation, and / or decoding / encoding. Furthermore, the first electronic device 1' may include a centralized unit O-CU (O-RAN Centralized Unit) as a component that manages the interface between the core network and the RAN and coordinates the operation of various components such as radio units and distributed units. In addition, the first electronic device 1' may include any number of subarrays 10, similar to the first electronic device 1 shown in Figure 2.

[0039] As shown in Figure 3, the distributed unit O-DU20 may include, for example, a channel estimation unit 22, a weight calculation unit 24, and a weight transmission unit 26. The channel estimation unit 22 and the weight calculation unit 24 may be based on the same concept as those provided by the first electronic device 1 described in Figure 2. The weight transmission unit 26 has the function of transmitting information to the weight regeneration unit 32, which will be described later, when the weight regeneration unit 32 regenerates weights. For example, the weight transmission unit 26 has the function of generating a beam ID and transmitting information related to that beam ID. The beam ID generated by the weight transmission unit 26 is used to transmit pre-coded weights in the C-Plane. In the O-RAN standard, predefined-beam beamforming, weight-based dynamic beamforming, attribute-based dynamic beamforming, and channel-information-based beamforming are defined as beamforming methods. Hereinafter, it is assumed that either predefined-beam beamforming or weight-based dynamic beamforming will be used from the above methods.

[0040] As shown in Figure 3, the wireless unit O-RU30 may include, for example, a weight regeneration unit 32 and a precoder 34. The first electronic device 1' may include a precoder 34 corresponding to each of any multiple subarrays 10, similar to the first electronic device 1 described in Figure 2. The precoder 34 may be based on a similar concept to that of the first electronic device 1 described in Figure 2. The weight regeneration unit 32 has the function of regenerating beamforming weights. The weight regeneration unit 32 has the function of regenerating beamforming weights from, for example, a beam ID transmitted by the C-Plane, or a set of weight IQ data.

[0041] At least one of the functional components shown in Figure 3 may be configured to include, for example, at least one of software and hardware resources. In one embodiment, at least one of the aforementioned functional components may be configured by specific means in which software and hardware resources cooperate. The first electronic device 1' according to one embodiment may not include some of the functional components shown in Figure 3, or it may include functional components other than those shown in Figure 3.

[0042] <Channel estimation by the first electronic device according to one embodiment> Next, channel estimation by the first electronic device 1 or 1' according to one embodiment will be described. The channel estimation described below may be performed by the channel estimation unit 22 in the first electronic device 1 or 1'. The following description will use the first electronic device 1 according to one embodiment as an example, but the same can be applied to the first electronic device 1' according to one embodiment.

[0043] In one embodiment, the channel estimation unit 22 estimates (represents) the propagation channel based on parameters (direction and / or distance) indicating the position between the base station gNB and the terminal UE. As a method for estimating the propagation channel, the MMSE (Minimum Mean Square Error) method using a reference signal with a known sequence, as described in the following reference [1], is widely employed. (Reference [1]: Takahiko Tsutsumi, et al., "Study on the Influence of Channel Information Error in Various Spatial Division Multiplexing Methods", [online], September 2004, IEICE Transactions on Electronics, Information and Communication Engineers, Vol. J87-B, No. 9, pp. 1496-1504. [Retrieved October 28, 2024], Internet) <URL:https: / / search.ieice.org / bin / pdf_link.php?&category=B&lang=J&year=2004&fname=j87-b_9_1496&abst=> )

[0044] <Control of weight by the first electronic device according to one embodiment> Next, the control of weight by the first electronic device 1 or 1' according to one embodiment will be further described. The weight control described below may be performed by the weight calculation unit 24 in the first electronic device 1 or 1'. As with the description above, the first electronic device 1 according to one embodiment will be used as an example below, but the same can be applied to the first electronic device 1' according to one embodiment.

[0045] In one embodiment, the weight calculation unit 24 calculates the weights required for phase control of the signal.

[0046] In one embodiment, channel estimation may be performed based on the position information of the second electronic device 2 (terminal UE) when controlling the phase. In this case, the beam and null are controlled simultaneously by phase control. The device that controls the beam and null simultaneously can be realized with a hardware configuration similar to that of conventional devices that perform analog beamforming. Therefore, it is expected that the implementation cost of the hardware according to one embodiment can be reduced.

[0047] The analog weight control method described below (an algorithm for calculating weights when performing weight control with respect to the phase of a signal) can be applied to both fully digital beamforming and coupled hybrid beamforming. Furthermore, the analog weight control method described below can also be applied to purposes other than spatial multiplexing, such as suppressing interference between other cells.

[0048] The following describes the method for calculating the weights when performing weight control on the phase of the signal as described above. As an example of spatially extending null, the technique in the following reference [2] can be cited. (Reference [2]: IWAKUNI Tatsuhiko, 5 others, “Null-Space Expansion for Multiuser Massive MIMO Inter-User Interference Suppression in Time Varying Channels”, [online], May 2017, IEICE Transactions on Communications E100.B (5), 865-873. [Retrieved October 22, 2020], Internet<URL:https: / / www.jstage.jst.go.jp / article / transcom / E100.B / 5 / E100.B_2016EBP3136 / _pdf / -char / ja> )

[0049] Furthermore, we will explain the case where nulls are not spatially extended in the calculation of phase control weights. Here, we will describe an embodiment that maximizes the evaluation function. In conceiving this embodiment, we referred to the following reference [3]. (Reference [3]: Steven T. Smith, “Optimum Phase-Only Adaptive Nulling”, [online], July 7, 1999, IEEE Transactions on Signal Processing, Vol. 47, [Retrieved October 22, 2020], Internet <URL:https: / / ieeexplore.ieee.org / 9> )

[0050] Reference [3] discloses an evaluation function shown in equation (1). Reference [3] proposes a method for finding the weights that maximize the evaluation function shown in equation (1) by using a conjugate gradient method based only on phase. Reference [3] assumes that the weights have only a phase component. Equation (1) means searching for the weights that maximize SINR.

[0051]

number

[0052] In equation (1) above, S represents the correlation matrix of spatially propagated signals (steering vectors). R represents the correlation matrix of noise. w represents the weight vectors. H represents the complex conjugate transpose of the matrix.

[0053] However, in reference [3], user interference is not considered. Therefore, in the first electronic device 1 according to one embodiment, an evaluation function that takes user interference into account is used, as shown in the following equation (2). The first electronic device 1 according to one embodiment can calculate weights using the evaluation function shown in equation (2) in the same manner as in equation (1) above.

[0054]

number

[0055] In the above equation (2), S (i) This represents the correlation matrix of the spatially propagated signal to the i-th desired terminal UE (second electronic device 2). (k) This represents the correlation matrix of the spatially propagated signal to the k-th interfering terminal UE (a terminal UE other than the desired terminal UE (second electronic device 2)). (i) This represents the analog precoding weight for the i-th terminal UE (second electronic device 2). (i) This represents the noise correlation matrix for the i-th terminal UE (second electronic device 2). The subscript H of the weight vector represents the complex conjugate transpose.

[0056] The numerator on the right-hand side of equation (2) above represents the desired component. The first term in the denominator on the right-hand side of equation (2) represents the interference component. The second term in the denominator on the right-hand side of equation (2) represents the noise component.

[0057] The evaluation function shown in equation (2) above can be expressed using a channel matrix as shown in equation (3).

[0058]

number

[0059] In equation (3) above, the following equation (4) holds true.

number

[0060] In equation (4) above, h(i) represents the channel vector for the i-th terminal UE (second electronic device 2), and its size is [number of antennas in subarray 10N × number of antennas of terminal UE].

[0061] Furthermore, in the above equation (4), H (k) Similarly, for the k-th interfering terminal UE (second electronic device 2), excluding the i-th desired terminal UE (second electronic device 2), the following equation (5) can be obtained.

number

[0062] For the sake of simplicity, we assume here that the terminal UE (second electronic device 2) has one antenna. Of course, we can also assume that the terminal UE (second electronic device 2) has two or more antennas.

[0063] Furthermore, as shown in equation (6) below, the evaluation function can also be expressed as the carrier-to-interference (power) ratio (SIR) by removing the noise component.

number

[0064] The numerator on the right-hand side of equation (6) above represents the desired component. The denominator on the right-hand side of equation (6) represents the interference component.

[0065] Furthermore, in the first electronic device 1 according to one embodiment, any algorithm that maximizes the evaluation function may be other methods besides the conjugate gradient method based solely on phase.

[0066] If the channel information only contains directional (direction) information, H (i) This can be expressed as shown in equation (7) below.

number

[0067] In equation (7) above, the subscript H represents the complex conjugate transpose.

[0068] From equation (7) above, the following equation (8) can be derived.

number

[0069] In the above equation (8), v (i) This is the steering vector for the i-th terminal UE (second electronic device 2), and is expressed as shown in equations (9) and (10) below.

[0070]

number

number

[0071] In equation (9) or (10) above, n is the number of antenna elements, m is the number of antenna elements, d is the distance between elements, θ is the direction of radiation (angle), and λ is the wavelength.

[0072] Similarly, H(k) can be calculated for the kth interfering terminal UE (second electronic device 2), excluding the i-th desired terminal UE (second electronic device 2), as shown in equation (11) below.

number

[0073] Furthermore, the steering vector shown in equation (9) above represents the case of a linear array where the antennas of the sub-array are arranged in a single row. In the case of a planar array where the antennas are arranged on a two-dimensional plane, the expression will be different from that of equation (9). Also, the form of equation (9) above is not limited to this, and other forms may be used.

[0074] Next, we will explain the case where null is spatially extended in the calculation of phase control weights. Spatially extending null to the weights mentioned above is considered to have advantages in the following respects.

[0075] First, (1) it is possible to achieve tracking speeds equivalent to those of digital processing. The analog processing described above is assumed to be inferior to digital processing in terms of adaptability to channel fluctuations. However, the first electronic device 1 according to one embodiment can improve tracking performance compared to conventional analog beamforming control by spatially expanding the null. That is, according to the first electronic device 1 according to one embodiment, by spatially expanding the null, even if the position of the terminal UE moves slightly, the moved position can be covered by the expanded null.

[0076] Next, (2) a reduction in processing speed and a reduction in power consumption can be achieved. If the adaptability due to channel fluctuations is equivalent to that of conventional analog beamforming, then the frequency of weight updates can be reduced by spatially expanding the nulls. Therefore, according to the first electronic device 1 of one embodiment, the processing speed can be reduced, and consequently, power consumption can also be reduced.

[0077] In calculating analog weights, we will describe an embodiment that maximizes the evaluation function, even when the null is spatially extended, similar to the case where it is not extended.

[0078] The equation obtained by applying the method of spatially expanding null to the evaluation function shown in the above equation (2) can be expressed as the following equation (12).

Equation

[0079] In the above equation (12), the following equations (13) and (14) hold.

Equation

Equation

[0080] In the above equation (14), h (k) represents the channel vector of the k-th interfering terminal UE (a terminal UE other than the desired terminal UE (the second electronic device 2)). h + (k)(l+) represents the l-th extended channel vector of the k-th interfering terminal UE (a terminal UE other than the desired terminal UE (the second electronic device 2)). Also, q represents the extension order.

[0081] The first electronic device 1 according to an embodiment may obtain a weight that maximizes the above equation (12) by using the conjugate gradient method based only on phase disclosed in the above reference [2].

[0082] Also, similar to that shown in the above equation (6), the evaluation function can be set as the SIR excluding the noise component. In the first electronic device 1 according to an embodiment, other methods than the conjugate gradient method based only on phase may be used as long as they are algorithms that maximize the evaluation function.

[0083] When the channel information has only direction (azimuth) information, each component of the following equation (15) can be expressed as in the following equations (16) and (17).

Equation

Equation

number

[0084] Here, θ q+ This is set by adding or subtracting some angle from the direction θ where the k-th interference terminal UE (second electronic device 2) is located. This expands the null region by creating multiple additional nulls in the θ direction. Equation (17) also expresses the expansion of nulls in a linear array configuration where the antennas are arranged in one dimension. On the other hand, in other antenna configurations such as planar array antennas, it is common to use the zenith angle in addition to the azimuth angle (θ) to specify the direction of the terminal UE. In that case, channel vectors with angles changed for both the azimuth angle and the zenith angle can be inserted.

[0085] Furthermore, the evaluation function shown in equation (2) above, when a method for spatially extending nulls is applied, can also be expressed as in equation (18).

number

[0086] In one embodiment, the first electronic device 1 may use the phase-only conjugate gradient method disclosed in the above reference [2] to determine the weight that maximizes equation (18). Here, q is the extension order when spatially extending the null. Also, the h shown in the following equation (19) (k(l)) This represents the l-th extended channel vector for the k-th interfering terminal UE (a terminal UE other than the desired terminal UE (second electronic device 2)).

number

[0087] The weights obtained using the evaluation function shown in equation (18) above have the following characteristics: that is, w (i)This contains only phase information. Furthermore, the weights obtained by the evaluation function shown in equation (18) above also have the characteristics shown in equation (20) or equation (21).

number

number

[0088] Furthermore, as shown in equation (6) above, the SIR can also be maximized by removing the noise component. In the first electronic device 1 according to one embodiment, any algorithm that maximizes the evaluation function may be other methods other than the conjugate gradient method based solely on phase.

[0089] Up to this point, we have described a method for obtaining weight vectors by calculating an algorithm using the conjugate gradient method based solely on phase. In addition to the method described above, another approach is to create a codebook of candidate weight vectors and input it into the evaluation function described above to find the optimal weights.

[0090] <Channel estimation by the first electronic device according to another embodiment>

[0091] In analog beamforming, channel estimation often involves a very large number of antenna elements (for example, FR2 has around 100 antenna elements). Therefore, attempting to calculate the channel matrix in the conventional way can result in an enormous amount of computation.

[0092] Therefore, in one embodiment, the first electronic device 1 (the channel estimation unit 22) may perform channel estimation in a simplified manner based only on the location information of the second electronic device 2 (terminal UE). Here, the location information of the second electronic device 2 (terminal UE) may, in the simplest example, be only the direction (angle) of the second electronic device 2 (terminal UE) relative to the first electronic device 1. Alternatively, the location information of the second electronic device 2 (terminal UE) may be only the direction (angle) of the second electronic device 2 (terminal UE) relative to the first electronic device 1, and the distance of the second electronic device 2 (terminal UE) relative to the first electronic device 1. Even if channel estimation is performed in this simplified manner, it can function well as massive MIMO when a Line of Site (LOS) environment is assumed. Furthermore, future changes in channel information may be predicted based on channels estimated in the past through channel estimation.

[0093] Here, when channel estimation is performed based on the direction (orientation), i.e., phase parameter, the direction of the second electronic device 2 (UE) as seen from the first electronic device 1 (gNB) may be estimated. In this case, for example, the phase information may be determined based on the SSB index selected by SSB (Synchronization Signal Block) search. Alternatively, for example, the direction of arrival of radio waves received from the UE may be estimated by an array antenna. Alternatively, for example, the direction of arrival of radio waves received from the UE may be estimated by utilizing functions installed in the application, such as vehicle-to-everything (V2X) communication.

[0094] Alternatively, when channel estimation is performed based on distance, i.e., the gain parameter, for example in a 5G framework, the estimation may be performed as follows: For example, distance information estimated by the UE may be fed back to the gNB in ​​the uplink direction by means of the RRC layer's Measurement Report. In this case, the distance information estimated by the UE may be the result of calculating RSRP (Reference Signal Received Power) based on the SSB transmitted from the gNB. Alternatively, feedback of the CSI-report calculated by the UE may be used for the CSI-RS (Channel State Information RS) transmitted by the gNB. Alternatively, the UE may transmit SRS, and the gNB may estimate the distance based on the received SRS strength.

[0095] When channel estimation is performed by taking into account not only the phase parameters and / or gain parameters mentioned above, but also time parameters, i.e., channel prediction parameters, future channels may be predicted from previously estimated channel information. In this case, for example, linear prediction may be used, or an AR model (AutoRegressive model) in time series analysis may be used.

[0096] As mentioned above, the simplest parameter used for channel estimation is phase information only (steering vector). Alternatively, both phase and gain information can be used as parameters for channel estimation.

[0097] The method for determining parameters such as the direction of the UE relative to the gNB, or the distance to the UE estimated by the gNB, is not limited to those described above. For example, methods that estimate the UE's location from wireless quality statistical data using machine learning are also conceivable. Alternatively, channel estimation may be performed using a reference signal (SRS (Sounding Reference Signal) or CSI-RS (Channel State Information RS)) that is standardly implemented in 5G systems.

[0098] <Switching of operating modes by the first electronic device according to one embodiment> Next, the operation of the first electronic device 1 or 1' according to one embodiment will be further described. The following description will use the first electronic device 1 according to one embodiment as an example, but the same can be applied to the first electronic device 1' according to one embodiment.

[0099] An electronic device 1 according to one embodiment may have two operating modes, such as a first operating mode and a second operating mode. Here, the first operating mode may be an operating mode in which analog weights are calculated so as to point both the beam and the null simultaneously, as in the method described above. The second operating mode may be an operating mode in which analog weights are calculated so as to form only the beam using a steering vector.

[0100] In the first operating mode, the accuracy of weight calculation deteriorates in areas where the reception level of the terminal UE (second electronic device 2) is low, leading to a worse SINR and potentially reduced throughput. For example, this situation is expected to occur when the terminal UE (second electronic device 2) is near the cell edge. In such cases, calculating the analog weight using the second operating mode can improve the SINR.

[0101] Therefore, as shown in the flowchart of Figure 5, after the operation has started, if the determination condition exceeds the threshold in step S11, the analog weight may be calculated by operating in the first operating mode (step S13). On the other hand, if the determination condition does not exceed the threshold in step S11, the analog weight may be calculated by operating in the second operating mode (step S15). The determination condition in step S11 may be a measured value of the terminal UE (second electronic device 2) (e.g., received SINR), or it may be a value calculated from the estimated channel, or any other condition.

[0102] Furthermore, in sub-array hybrid beamforming, the flow shown in Figure 5 may be performed for each sub-array, or the switching may be performed collectively (unified) across all sub-arrays.

[0103] As described above, the first electronic device 1 or 1' according to one embodiment comprises a plurality of sub-arrays 10, each containing a plurality of antenna elements, and communicates with a plurality of second electronic devices 2 using massive MIMO. The first electronic device 1 or 1' also performs beamforming with phase control only. This causes the first electronic device 1 or 1' to direct the beam formed by one of the plurality of sub-arrays 10 towards a desired device among the plurality of second electronic devices 2. Furthermore, the first electronic device 1 or 1' causes the null formed by the one sub-array 10 to direct the device among the plurality of second electronic devices 2 other than the desired device.

[0104] As described above, the electronic device 1 or 1' according to one embodiment may include a channel estimation unit 22 for estimating channel information. In this case, the first electronic device 1 or 1' according to one embodiment may perform weight control based on the channel information estimated by the channel estimation unit 22.

[0105] The channel estimation unit 22 may estimate channel information based on at least one direction among the plurality of second electronic devices 2. Alternatively, the channel estimation unit 22 may estimate channel information based on at least one direction among the plurality of second electronic devices 2 and the distance from the first electronic device 1 or 1' to the second electronic device 2. In this case, the channel estimation unit 22 may estimate channel information based on the temporal change of said channel information.

[0106] Furthermore, as described above, the electronic device 1 or 1' according to one embodiment may include a weight calculation unit 24 that performs the weight control described above. In this case, the weight calculation unit 24 may perform weight control by controlling only the phase of the radio waves. Alternatively, the weight calculation unit 24 may perform weight control by controlling both the amplitude and phase of the radio waves.

[0107] According to the first electronic device 1 or 1' of one embodiment, when realizing massive MIMO, it is possible to simplify the hardware configuration, reduce processing costs, and provide good communication quality.

[0108] <Null extension in the frequency domain> In the embodiments described above, the case of spatially extending the null was explained. That is, in the embodiments described above, the null was formed in the spatial domain (direction). In one embodiment, the first electronic device 1 may perform null extension in the frequency domain when calculating the phase control weights. That is, in one embodiment, when realizing wireless communication by massive MIMO, the first electronic device 1 may also form (extend) multiple nulls in the frequency domain (bandwidth). In this way, the first electronic device 1 can form two types of nulls, in the spatial domain and the frequency domain, by performing signal processing once. According to the first electronic device 1 of one embodiment, the null interference rejection capability can be improved over a relatively wide frequency band (SINR can be further improved). Such embodiments will be described further below.

[0109] Equations (16) and (17) above consider only spatial null extension. Using equation (17), the frequency at which a null is to be formed (the reciprocal of the wavelength λ) can be parameterized to calculate the weight v. In equation (16), θ represents the azimuth angle of the desired UE (second electronic device 2). Also, in equation (16), θ 1+ ,…,θ q+This shows an embodiment in which the azimuth angle to which null extension is to be performed has been added. In other words, this shows an embodiment in which null extension is performed for the interference terminal UE (second electronic device 2) with azimuth angles #1 to #(q-1).

[0110] Next, we will describe an embodiment that maximizes the evaluation function in order to extend the null not only to the spatial null but also to the radio frequencies used for communication when calculating the analog weight. In one embodiment, the first electronic device 1 may use, for example, the following equation (22) as a signal processing calculation formula for further extending the null in the frequency domain in addition to the spatial null extension. Below, we will describe an example of converting the parameters for extending the null in the frequency domain into wavelength form while maintaining the expression format of equations (16) and (17) above.

[0111]

number

[0112] In equation (22) above, the components shown in the upper row may correspond to the center frequency (wavelength). These elements may have the same meaning as the elements shown in the upper row of equation (16) above. Also, in equation (22) above, the components shown in the middle row may correspond to the frequencies for which null extension is to be performed. This may also include the reference direction with respect to the interference terminal UE (second electronic device 2). Also, in equation (22) above, the components shown in the lower row may correspond to the number of frequencies for which null extension is to be performed generalized to N.

[0113] Furthermore, if we adopt equation (22) above, then equation (23) holds true.

number

[0114] When using equation (22) above, you may use equation (24) below instead of equation (17) above.

number

[0115] Furthermore, as shown in equations (25) and (26) below, an additional factor may be added for the reference direction.

number

number

[0116] When setting the frequency to which you want to extend the null according to equation (23) above, the bandwidth BW of the baseband signal should be determined by the resolution (Δ f How many divisions should be made (p i ) can be set. Also, when using the above equation (23), if we consider the extension of the center frequency to both sides, p iΔ can be a positive or negative value. When using equation (23) above, the value of p may be appropriately selected depending on the number of antenna elements and / or the aperture of the array. For example, increasing the number of antenna elements will make the null in the frequency domain sharper, so more null may be required. The opposite is true when decreasing the number of antenna elements. Here, Δ f The resolution does not need to be a fixed value; it can be arbitrarily set according to the frequency band that forms the null or the direction of the interfering terminal UE.

[0117] Based on equations (22) and (23) above, the null can be extended in the frequency domain even in a single-carrier transmission system. The above method assumes an analog beamformer and performs beam and null formation, so it can be applied regardless of the baseband modulation scheme. In the case of a wireless system using multiple subcarriers, for example, in a 5G system, Δf may be set to 15kHz, 30kHz, 60kHz, or 120kHz by referring to the subcarrier spacing of the OFDM scheme. Also, in the case of a wireless system using a single carrier, the bandwidth occupied by wireless communication may be divided into arbitrary widths and Δf may be set in advance. For example, a 100MHz communication bandwidth may be divided into 1000 equal parts and Δf may be set to 100kHz.

[0118] Figure 6 shows an example of the bandwidth of a signal at a given frequency and the frequency of null extension relative to that bandwidth. In Figure 6, the horizontal axis represents frequency and the vertical axis represents gain. The weight for null extension at a given frequency is the center frequency f of the wireless communication, as shown in Figure 6. c f pi It may be set with a symmetrical bandwidth. In Figure 6, the frequency of null extension with respect to the signal bandwidth BW is f pi This is shown as follows. Here, the null extension frequency does not necessarily have to be set as the entire width of ±BW / 2.

[0119] On the other hand, when wireless communication is broadband, the entire frequency band may be divided into multiple subbands, as shown in Figure 7, for example, and null extension weights in the frequency and angular directions may be set for the center frequency of each subband. Alternatively, weights may be generated by performing weighting or averaging processing using these weights. For example, in Figure 7, after determining the null extension weights for the two subbands f1±fpi and f2±fpi, weights may be applied to the entire bandwidth by performing averaging or weighting processing. Alternatively, instead of dividing the subbands by frequency, the division may be based on the direction of the null extension relative to the interfering terminal UE. In other words, the channel matrix of equation (22) above may be divided into arbitrary combinations of rows to generate null extension weights, and finally these may be combined to generate the final weights. Furthermore, antenna elements within a subarray may be grouped, and null extension weights may be generated for different frequencies and angles for each group. This eliminates the beamwidth narrowing caused by using all the numerous antenna elements.

[0120] As described above, the first electronic device 1 according to one embodiment can eliminate interference by expanding nulls in the frequency domain of massive MIMO, by designing the center frequency of the radio wave and the frequency of the extended target as parameters.

[0121] Figure 8 shows an example of a simulation of null extension in the frequency axis by the first electronic device 1 according to one embodiment. The dashed graph C1 in Figure 8 shows an example of null space extension with phase-adaptive nulling only, i.e., the spatial extension described above. The solid graph C2 in Figure 8 shows an example of broadband null space extension with phase-adaptive nulling only, i.e., null extension in both space and frequency.

[0122] As described above, the first electronic device 1 or 1' according to one embodiment comprises a plurality of subarrays 10, each containing a plurality of antenna elements, and communicates with a plurality of second electronic devices 2 using massive MIMO. Furthermore, the first electronic device 1 or 1' according to one embodiment may be controlled so that the beam formed by one of the plurality of subarrays 10 is directed toward a desired second electronic device 2 among the plurality of second electronic devices 2. Furthermore, the first electronic device 1 or 1' according to one embodiment may be controlled so that a null is formed in the spatial domain and frequency domain by the single subarray 10. The first electronic device 1 or 1' according to one embodiment may be controlled so that a null is formed in the spatial and frequency domains corresponding to a second electronic device 2 other than the desired second electronic device 2 among the plurality of second electronic devices 2.

[0123] Recent wireless communication systems are based on broadband transmission, and in 5G systems, for example, the maximum communication bandwidth can reach 400 MHz. In conventional multi-user MIMO using analog beamformers, null formation is performed only in the target frequency component (i.e., the center frequency). Such nulls are generally narrowband, and interference rejection is not sufficiently performed in other frequency components. Therefore, even if the null space is expanded in the angular (spatial) direction, interference between terminal UEs may remain, and communication quality may deteriorate.

[0124] According to the first electronic device 1 of one embodiment, in an analog beamformer controlled only by phase, a wideband null can be formed by extending the null space not only in the angular (spatial) direction but also in the frequency direction. Therefore, even in wireless communication systems that assume wideband transmission, stable multi-user MIMO spatial multiplexing transmission can be realized with a simplified hardware configuration.

[0125] While embodiments relating to this disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art will find it easy to make various modifications or alterations based on this disclosure. Therefore, it should be noted that these modifications or alterations are included within the scope of this disclosure. For example, the functions included in each component or step can be rearranged in a logically consistent manner, and multiple components or steps can be combined into one or divided. While embodiments relating to this disclosure have been described primarily in terms of apparatus, embodiments relating to this disclosure can also be realized as methods including steps performed by each component of the apparatus. Embodiments relating to this disclosure can also be realized as methods, programs, or storage media or recording media on which programs are recorded, executed by a processor in an electronic device. These should also be understood to be included within the scope of this disclosure.

[0126] The first electronic device 1 according to one embodiment may be implemented using analog beamforming, hybrid beamforming, or digital beamforming.

[0127] The embodiments described above are not limited to implementation as the first electronic device 1. For example, the embodiments described above may be implemented as a system including the first electronic device 1. Also, the embodiments described above may be implemented as a system including the first electronic device 1 and the second electronic device 2. Furthermore, the embodiments described above may be implemented, for example, as a control method for the first electronic device 1 or as a control method for equipment such as a system including the first electronic device 1. Moreover, the embodiments described above may be implemented, for example, as a program executed by equipment such as the first electronic device 1 or a system including the first electronic device 1, or by an information processing device (e.g., a computer). Furthermore, in the technology of this disclosure, not all of the components of the first electronic device 1 and / or the system including the first electronic device 1 have to reside in a single enclosure or the like. For example, the controllers and / or memory units of each component of the first electronic device 1 and / or the system including the first electronic device 1 may be connected to each other by a network consisting of wired, wireless, or a combination thereof.

[0128] Although an electronic device and system according to one embodiment have been described above, the electronic device, system, control method for the electronic device, and / or program according to one embodiment may be implemented, for example, as follows. [Note 1] An electronic device comprising multiple subarrays, each containing multiple antenna elements, that performs massive MIMO communication with multiple other electronic devices, Electronic equipment that performs beamforming by weight control of the signal phase such that a beam formed by one of the plurality of subarrays is directed toward a desired device among the plurality of other electronic equipment, and a null formed by the one subarray is directed toward a device other than the desired device among the plurality of other electronic equipment. [Note 2] It includes a channel estimation unit that estimates channel information, The electronic device described in Appendix 1, which performs weight control based on channel information estimated by the channel estimation unit. [Note 3] The electronic device described in Appendix 2, wherein the channel estimation unit estimates the channel information based on at least one direction among the plurality of other electronic devices. [Note 4] The electronic device according to Appendix 2, wherein the channel estimation unit estimates the channel information based on the direction of at least one of the plurality of other electronic devices and the distance from the electronic device to the other electronic devices. [Note 5] The channel estimation unit is an electronic device according to Appendix 3 or 4, which estimates the channel information based on the temporal changes in the channel information. [Note 6] The system includes a weight calculation unit that performs the aforementioned weight control, The weight calculation unit performs the weight control by controlling the phase of the signal, as described in any one of the electronic devices described in Appendix 1 to 5. [Note 7] The system includes a weight calculation unit that performs the aforementioned weight control, The weight calculation unit performs the weight control by controlling only the phase of the signal, as described in any one of the electronic devices described in Appendix 1 to 5. [Note 8] The electronic device according to any one of the appendices 1 to 7, wherein the one subarray is controlled to form nulls in the spatial domain and the frequency domain. [Note 9] The electronic device according to Appendix 8, which controls the plurality of other electronic devices to form a null in the spatial domain and frequency domain corresponding to the device other than the desired electronic device. [Note 10] A system including an electronic device and multiple other electronic devices, The aforementioned electronic device is It comprises multiple subarrays, each containing multiple antenna elements, and performs massive MIMO communication with the aforementioned multiple other electronic devices. A system that performs beamforming by weight control of the signal phase such that a beam formed by one of the plurality of subarrays is directed toward a desired device among the plurality of other electronic devices, and a null formed by that one subarray is directed toward a device other than the desired device among the plurality of other electronic devices. [Note 11] A control method for an electronic device that includes multiple subarrays, each containing multiple antenna elements, and performs massive MIMO communication with multiple other electronic devices, A method for controlling electronic equipment, comprising the step of performing beamforming by weight control of the phase of a signal such that a beam formed by one of the plurality of subarrays is directed toward a desired device among the plurality of other electronic equipment, and a null formed by the one subarray is directed toward a device other than the desired device among the plurality of other electronic equipment. [Note 12] An electronic device that has multiple sub-arrays, each containing multiple antenna elements, and performs massive MIMO communication with multiple other electronic devices, A program that performs a step of beamforming by weight control of the signal phase such that a beam formed by one of the plurality of subarrays is directed toward a desired device among the plurality of other electronic devices, and a null formed by the one subarray is directed toward a device other than the desired device among the plurality of other electronic devices. [Explanation of symbols]

[0129] 1,1' 1st electronic equipment (base station (gNB)) 10 Sub-arrays (Antenna Arrays) 20 O-DU(O-RAN Distributed Unit) 22 Channel Estimation Unit 24 Weight Calculation Unit 26 Weight transmission section 30 O-RU(O-RAN Radio Unit as defined by O-RAN) 32 Weight regeneration unit 34 Precoder 2. Second Electronic Device (Terminal (UE))

Claims

1. An electronic device comprising multiple subarrays, each containing multiple antenna elements, that performs massive MIMO communication with multiple other electronic devices, Electronic equipment that performs beamforming by weight control of the signal phase such that a beam formed by one of the plurality of subarrays is directed toward a desired device among the plurality of other electronic equipment, and a null formed by that one subarray is directed toward a device other than the desired device among the plurality of other electronic equipment.

2. It includes a channel estimation unit that estimates channel information, The electronic device according to claim 1, wherein the weight control is performed based on the channel information estimated by the channel estimation unit.

3. The electronic device according to claim 2, wherein the channel estimation unit estimates the channel information based on at least one direction among the plurality of other electronic devices.

4. The electronic device according to claim 2, wherein the channel estimation unit estimates the channel information based on the direction of at least one of the plurality of other electronic devices and the distance from the electronic device to the other electronic devices.

5. The electronic device according to claim 3 or 4, wherein the channel estimation unit estimates the channel information based on the temporal changes in the channel information.

6. The system includes a weight calculation unit that performs the aforementioned weight control, The electronic device according to claim 1, wherein the weight calculation unit performs weight control by controlling the phase of the signal.

7. The system includes a weight calculation unit that performs the aforementioned weight control, The electronic device according to claim 1, wherein the weight calculation unit performs weight control by controlling only the phase of the signal.

8. The electronic device according to claim 1, wherein the one subarray is controlled to form nulls in the spatial domain and the frequency domain.

9. The electronic device according to claim 8, which controls the formation of nulls in the spatial domain and frequency domain corresponding to the devices other than the desired electronic device among the plurality of other electronic devices.

10. A system including an electronic device and multiple other electronic devices, The aforementioned electronic device is It comprises multiple subarrays, each containing multiple antenna elements, and performs massive MIMO communication with the aforementioned multiple other electronic devices. A system that performs beamforming by weight control of the signal phase such that a beam formed by one of the plurality of subarrays is directed toward a desired device among the plurality of other electronic devices, and a null formed by that one subarray is directed toward a device other than the desired device among the plurality of other electronic devices.

11. A control method for an electronic device that includes multiple subarrays, each containing multiple antenna elements, and performs massive MIMO communication with multiple other electronic devices, A method for controlling electronic equipment, comprising the step of performing beamforming by weight control of the phase of a signal such that a beam formed by one of the plurality of subarrays is directed toward a desired device among the plurality of other electronic equipment, and a null formed by the one subarray is directed toward a device other than the desired device among the plurality of other electronic equipment.

12. An electronic device that has multiple sub-arrays, each containing multiple antenna elements, and performs massive MIMO communication with multiple other electronic devices, A program that performs a beamforming step by weight control of the signal phase such that a beam formed by one of the plurality of subarrays is directed toward a desired device among the plurality of other electronic devices, and a null formed by that one subarray is directed toward a device other than the desired device among the plurality of other electronic devices.

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