Beamforming Schemes in High-Rank Transmission

Abstract

Embodiments of the present disclosure relate to an apparatus, method, device, and computer-readable storage medium for a beamforming scheme in high-rank transmission in a massive multiple-input multiple-output system. The method includes determining a target beam for carrying the transmission of a reference signal from a base station to a user equipment; determining a target arrangement of a plurality of ports formed at an antenna array of the base station; and transmitting different portions of the target beam to the user equipment through the plurality of ports based on the target arrangement. In this way, a new beamforming method is proposed for high-rank transmission selection in a multi-port communication system in massive MIMO. The gNB will only select the best beams of different halves with the same polarity to maintain the QCL principle.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of telecommunications, and more particularly, to an apparatus, a method, a device, and a computer-readable storage medium for a beamforming scheme in high-rank transmission in a massive multiple-input multiple-output (MIMO) system. Background Art

[0002] Massive MIMO technology is one of the important solutions to improve the cell capacity of 5G New Radio (NR) systems. One of the schemes for massive MIMO is the Grid of Beams (GOB) scheme. In addition to the GOB scheme, Eigen Beam Based Beamforming (EBB) is another scheme for massive MIMO. Summary of the Invention

[0003] Generally, example embodiments of the present disclosure provide a solution for a beamforming scheme in high-rank transmission.

[0004] In a first aspect, a base station is provided. The base station includes at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, cause the base station to at least determine a target beam for carrying the transmission of a reference signal from the base station to a user equipment; determine a target arrangement of a plurality of ports formed at an antenna array of the base station; and transmit different parts of the target beam to the user equipment through the plurality of ports based on the target arrangement.

[0005] In a second aspect, a method is provided. The method includes determining a target beam for carrying the transmission of a reference signal from the base station to a user equipment; determining a target arrangement of a plurality of ports formed at an antenna array of the base station; and transmitting different parts of the target beam to the user equipment through the plurality of ports based on the target arrangement.

[0006] In a third aspect, a device is provided. The device includes means for determining a target beam for carrying the transmission of a reference signal from the base station to a user equipment at the base station; means for determining a target arrangement of a plurality of ports formed at an antenna array of the base station; and means for transmitting different parts of the target beam to the user equipment through the plurality of ports based on the target arrangement.

[0007] In a fourth aspect, a computer-readable medium having a computer program stored thereon is provided. The computer program, when executed by at least one processor of a device, causes the device to perform the method according to the second aspect.

[0008] Other features and advantages of the embodiments of the present disclosure will also be apparent when reading the following detailed description of the embodiments in conjunction with the accompanying drawings, which illustrate the principles of the embodiments of the present disclosure by way of example. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Embodiments of the present disclosure are presented in an illustrative sense, and their advantages are explained in more detail below with reference to the accompanying drawings, in which

[0010] Figure 1 an example environment in which example embodiments of the present disclosure may be implemented is shown;

[0011] Figure 2 a flowchart of an example method of beamforming schemes in high-rank transmissions according to some example embodiments of the present disclosure is shown;

[0012] Figure 3 an example of CSI-RS mapping according to some example embodiments of the present disclosure is shown;

[0013] Figure 4A and Figure 4B an example of a candidate port arrangement according to some example embodiments of the present disclosure is shown;

[0014] Figures 5A to 5C an example of a candidate port arrangement according to some example embodiments of the present disclosure is shown;

[0015] Figure 6 an example of CSI-RS mapping according to some example embodiments of the present disclosure is shown;

[0016] Figure 7 a simplified block diagram of a device suitable for implementing example embodiments of the present disclosure is shown; and

[0017] Figure 8 a block diagram of an example computer-readable medium according to some embodiments of the present disclosure is shown.

[0018] Throughout the drawings, the same or similar reference numerals denote the same or similar elements. DETAILED DESCRIPTION

[0019] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that the description of these embodiments is only for the purpose of illustration and to assist those skilled in the art in understanding and implementing the present disclosure, and does not represent any limitation on the scope of the present disclosure. The disclosure described herein may be implemented in various other ways than those described below.

[0020] 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 the present disclosure pertains.

[0021] References to "an embodiment", "embodiment", "example embodiment", etc. in this disclosure indicate that the described embodiments may include a particular feature, structure, or characteristic, but not necessarily every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an example embodiment, it is considered within the knowledge of those skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments (whether or not explicitly described).

[0022] It should be understood that although the terms "first" and "second" etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish the functions of various elements. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0023] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the example embodiments. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises", "comprising", "has", "having", "includes", and / or "including" when used herein specify the presence of the stated features, elements, and / or components, etc., but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0024] As used in this application, the term "circuit" may refer to one or more or all of the following:

[0025] (a) A pure hardware circuit implementation (such as an implementation using only analog and / or digital circuitry), and

[0026] (b) A combination of hardware circuitry and software, such as (where applicable):

[0027] (i) A combination of analog and / or digital hardware circuitry and software / firmware, and

[0028] (ii) Any part of a hardware processor (including a digital signal processor), software, and memory with software that work together to cause a device (such as a mobile phone or a server) to perform various functions, and

[0029] (c) A hardware circuit and / or processor, such as a microprocessor or a part of a microprocessor, that requires software (e.g., firmware) to operate, but the software may not be present when not needed for operation.

[0030] The definition of circuitry is suitable for all uses of the term in this application (including in any claims). As another example, as used in this application, the term circuitry also encompasses implementations of only hardware circuits or processors (or multiple processors) or portions of hardware circuits or processors and their (or their) accompanying software and / or firmware. For example, if applicable to a particular claim element, the term circuitry also encompasses a baseband integrated circuit or a processor integrated circuit for a mobile device, or a similar integrated circuit in a server, a cellular network device, or other computing or network devices.

[0031] As used herein, the term "communication network" refers to a network that follows any suitable communication standard, such as a fifth-generation (5G) system, Long-Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), NarrowBand Internet of Things (NB-IoT), etc. In addition, the communication between a terminal device and a network device in a communication network can be performed according to any suitable generation of communication protocol, including but not limited to the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, future fifth-generation (5G) New Radio (NR) communication protocol, and / or any other protocol known currently or developed in the future. Embodiments of the present disclosure can be applied to various communication systems. Given the rapid development of communication, there will of course also be future types of communication technologies and systems in which the present disclosure can be implemented. The scope of the present disclosure should not be regarded as limited to the above systems.

[0032] As used herein, the term "network device" refers to a node in a communication network through which a terminal device accesses the network and receives services therefrom. The network device can refer to a base station (BS) or an access point (AP), such as Node B (NodeB or NB), evolved Node B (eNodeB or eNB), NR next-generation Node B (gNB), remote radio unit (RRU), radio header (RH), remote radio head (RRH), relay, low-power nodes such as femto, pico, etc., depending on the terms and technologies applied. The RAN split architecture includes a gNB-CU (centralized unit that hosts RRC, SDAP, and PDCP) that controls multiple gNB-DUs (distributed units that host RLC, MAC, and PHY). The relay node can correspond to the DU part of an IAB node.

[0033] The term "terminal device" refers to any terminal device capable of wireless communication. By way of example and not limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). Terminal devices may include, but are not limited to, mobile phones, cellular phones, smart phones, IP voice (VoIP) phones, wireless local loop phones, tablet computers, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, game terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEE), laptop mounted devices (LME), USB dongles, smart devices, wireless client devices (CPE), Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated processing chain environment), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. A terminal device may also correspond to the mobile terminal (MT) portion of an integrated access and backhaul (IAB) node (also referred to as a relay node). In the following description, the terms "terminal device", "communication device", "terminal", "user equipment", and "UE" may be used interchangeably.

[0034] Although the functions described herein may be performed in fixed and / or wireless network nodes in various example embodiments, in other example embodiments, the functions may be implemented in a user equipment device such as a cellular phone or a tablet computer or a laptop or a desktop computer or a mobile IoT device or a fixed IoT device. For example, the user equipment device may be suitably equipped with corresponding capabilities as described in connection with fixed and / or wireless network nodes. The user equipment device may be a user equipment and / or a control device such as a chipset or a processor that is configured to control the user equipment when installed in the user equipment. Examples of such functions include a bootstrapping server function and / or a home subscriber server that may be implemented in the user equipment device by providing software to the user equipment device that is configured to cause the user equipment device to perform operations from the perspective of these functions / nodes.

[0035] Figure 1 An example communication network 100 in which embodiments of the present disclosure may be implemented is shown. As Figure 1As shown, the communication network 100 includes a network device 110 (also referred to hereinafter as a base station 110 or gNB 110) and a terminal device 120 (also referred to hereinafter as a user equipment 120 or UE 120). The terminal device 120 can communicate with the network device 110. It can be understood that Figure 1 The number of network devices and terminal devices shown is given for illustrative purposes and does not imply any limitation. The communication network 100 can include any suitable number of network devices and terminal devices.

[0036] Depending on the communication technology, the network 100 can be a Code Division Multiple Access (CDMA) network, a Time Division Multiple Access (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency Division Multiple Access (OFDMA) network, a Single Carrier Frequency Division Multiple Access (SC-FDMA) network, etc. The communication discussed in the network 100 can conform to any suitable standard, including but not limited to New Radio Access (NR), Long Term Evolution (LTE), LTE Evolution, Advanced LTE (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), cdma2000, and Global System for Mobile Communications (GSM), etc. In addition, the communication can be performed according to any generation of communication protocols known currently or developed in the future. Examples of communication protocols include but are not limited to the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols. The techniques described herein can be used for the above-mentioned wireless networks and radio technologies as well as other wireless networks and radio technologies. For clarity, certain aspects of the technique are described below for LTE, and LTE terms are used in most of the following descriptions.

[0037] As mentioned above, the massive MIMO technology is one of the important solutions to improve the cell capacity of 5G New Radio (NR) systems. One of the solutions for massive MIMO is the Grid of Beams (GOB) scheme. In addition to the GOB scheme, Eigen Beam Based Beamforming (EBB) is another solution for massive MIMO.

[0038] The current solutions in MIMO are based on long-term weights (both for GOB and EBB) for CSIRS mapping and short-term weights (Precoding Matrix Indicator (PMI) reported by the UE) for layer mapping in special multiplexing.

[0039] A specific UE has a channel H t between different Tx antennas N r and Rx antennas N k The transmitted signal is s k The signal at the receiver is r k The random noise is n k .

[0040] r k = H k * s + n k (1)

[0041] If the UE can transmit multiple layers in this channel, the channel shall be decomposed as follows:

[0042]

[0043] where U k and are both orthogonal matrices, is the matrix containing all eigenvectors. I is the identity matrix. The size of the matrix I can be used as an indicator of how many layers are supported in the channel.

[0044] Assume that the long-term weight of the CSIRS mapping is B k , and through CSIRS channel estimation, the signal at the receiver is:

[0045] r k = H k B k * s + n k (3)

[0046] Using an ordinary MRC receiver, the estimated signal at the receiver is

[0047]

[0048]

[0049] After replacing H with the decomposition function k :

[0050]

[0051]

[0052] If the signal can be transformed with , the signal at the receiver is transformed with the same matrix:

[0053]

[0054]

[0055] Finally, the signal is received in parallel. The short-term weight is used for this transformation, and if the reported PMI W k matches the transformation matrix , the signal can be received correctly.

[0056]

[0057] The problem is how to solve for the long - term weight B k 。

[0058] v l is the eigenvector of the channel H k and b n is the weight for each CSIRS port, and w n，l is the PMI reported by the UE for each CSIRS port and each layer.

[0059]

[0060] In the 2×2 mode, there is only one CSIRS port for each polarization, and the transformation matrix is:

[0061]

[0062] In the long - term weight calculation, it is reasonable to use the first beam of the channel to maintain the spatial multiplexing result.

[0063] However, in the 4×4 mode, there are two CSIRS ports for each polarization, and the transformation matrix is:

[0064]

[0065] In the 5G type - I codebook design, the PMI matrix is:

[0066]

[0067]

[0068] Using the current design in MIMO 4×4:

[0069]

[0070]

[0071] It can be seen that the occupied off - diagonal part is always non - zero, which means that there is always interference between layers in high - rank transmission.

[0072] In addition, 3GPP requests different CSIRS ports with a quasi - co - located (QCL) scheme in channel estimation and Doppler shift estimation (e.g., processes), which means that different CSIRS ports should have the same estimation result. If different CSIRS ports with different eigenvectors are allowed in the product, the QCL principle is violated.

[0073] Accordingly, the present disclosure proposes a solution for a beamforming scheme in high-rank transmission. In this scheme, the gNB can select the best beam for transmitting the reference signal from the gNB to the UE. To satisfy the QCL principle, the UE can transmit different parts of the selected beam through multiple ports. Each of the multiple ports is arranged in a vertical or horizontal direction in the antenna array of the gNB. In this way, a new beamforming method is proposed for large-scale MIMO selection high-rank transmission in a multi-port communication system. The gNB will only select the best beams of different halves with the same polarity to maintain the QCL principle.

[0074] The following combines Figure 2 to detail the principle and implementation of the present disclosure. Figure 2 FIG. shows a flowchart of an example method 200 of a beamforming scheme in high-rank transmission according to some example embodiments of the present disclosure. Method 200 can be implemented at the gNB 110 as shown in Figure 1 For the purpose of discussion, method 200 will be described with reference to Figure 1 Describe method 200.

[0075] At 210, the gNB 110 can determine a target beam for carrying the transmission of the reference signal from the gNB 110 to the UE120. Hereinafter, the target beam for carrying the transmission can be considered as the best beam selected by the gNB 110.

[0076] In some example embodiments, to obtain the best beam, the gNB 110 can request the UE120 to send a sounding reference signal (SRS) to the gNB 110. Based on the measurement of the SRS, the gNB110 can determine the target beam based on the measurement results.

[0077] In some example embodiments, the gNB 110 can also transmit additional reference signals to the UE 120. The UE 120 can measure the additional reference signals and determine the best receiving beam from the gNB 110. Then, the UE 120 can report an indication of the best receiving beam, such as the beam index of the receiving beam, to the gNB 110. Then, the gNB 110 can select the receiving beam reported by the UE 120 as the target beam. In this way, the gNB will only select the best beam instead of more beams.

[0078] At 220, the gNB 110 can determine the target arrangement of the multiple ports formed at the antenna array of the gNB 110.

[0079] At 230, in order to maintain the QCL principle, the gNB 110 may transmit different parts of the target beam through multiple ports based on the determined target arrangement. For example, by mapping different parts of the target beam to corresponding ports among the multiple ports. For example, the multiple ports may be regarded as the channel state information reference signal (CSI-RS) ports for transmitting CSI-RS at the gNB 110.

[0080] In some example embodiments, each of the multiple ports is arranged in a vertical or horizontal direction in the antenna array of the gNB 110. In this way, the selected target beam can be mapped to different CSI-RS ports of the same polarity, that is, different polarities will share the same beam to maintain the QCL principle.

[0081] Figure 3 An example of CSI-RS mapping according to some example embodiments of the present disclosure is shown. As Figure 2 shown, for the 4×4 mode, two beams 311 and 312 are transmitted from the antenna array 310 in a conventional manner. In this case, from the multiplexing layer directions of layer 1 313 and layer 2 314, it can be seen that the beams 311 and 312 from the CSI-RS have different directions, which does not follow the QCL principle.

[0082] On the contrary, if the optimal beam is mapped to different CSI-RS ports with weights for different halves, as Figure 3 shown, from the perspective of the CSI-RS, for the antenna array 320 and the two parts of the beams 321 and 322, then this mapping method will maintain the same direction between each port, which can be seen from the multiplexing layer directions of layer 1 323 and layer 2 324.

[0083] In some example embodiments, the gNB 110 may determine a set of candidate arrangements of the multiple ports by segmenting the antennas in the antenna array along at least one of the vertical direction and the horizontal direction of the antenna array, and determine the target arrangement of the multiple ports from the set of candidate arrangements.

[0084] For example, for the 4×4 mode, in one polarity, there are two CSI-RS ports. If the QCL principle is maintained, the beams used in these two CSI-RS ports should be the same, but it will cause much higher layer interference in the UE receiver. Therefore, the CSI-RS ports can be mapped to different parts of the beam.

[0085] Figure 4A and Figure 4B An example of candidate port arrangements for the 4×4 mode according to some example embodiments of the present disclosure is shown. As Figure 4AAs shown, the antennas at the antenna array 400 can form a first CSI-RS port 411 and a second CSI-RS port 412, while as Figure 4B shown, the antennas at the antenna array 400 can form a first CSI-RS port 421 and a second CSI-RS port 422.

[0086] Now, as described above, the problem of the non-zero non-diagonal part can be solved as follows.

[0087] In Figure 4A the example of, for each CSI-RS in the same polarity, the UE will observe different half-panel channels.

[0088]

[0089] For the transformation matrix:

[0090]

[0091]

[0092] The optimal beam v0 is replaced by the top_half and the bottom_half:

[0093]

[0094]

[0095] Remove the orthogonal part in the function:

[0096]

[0097] Finally, find a in the PMI to ensure minimum interference.

[0098] Looking back at another non-diagonal element:

[0099]

[0100] If the channel can refine two orthogonal eigenvectors, this non-diagonal element with the same phase in the PMI is perfectly 0. For the left-right splitting weights, as Figure 4B shown, the same conclusion can be obtained.

[0101] In addition, Figures 5A to 5C shows an example of a candidate port arrangement for the 8×8 mode according to some example embodiments of the present disclosure. According to the same consideration, the solution of the present invention can also support the mapping of 8 CSI-RS ports using different splitting methods, and each CSI-RS port will observe the same channel of the weighted part.

[0102] Figure 6 illustrates an example of CSI-RS mapping according to some example embodiments of the present disclosure. From Figure 6 it can be seen that CSI-RS ports 531 to 534 can be formed at the array 500, as Figure 5C shown in the optional port arrangement, and four parts of the beams 535-538 are respectively mapped to CSI-RS ports 531 to 534. From the perspective of CSI-RS, this mapping method will maintain the same direction between each port.

[0103] In addition, it can also be seen from Figure 6 that CSI-RS ports 521 to 524 can be formed at the array 500, as Figure 4B shown in the additional optional port arrangement, and four parts of the beams 525-528 are respectively mapped to CSI-RS ports 521 to 524. From the perspective of CSI-RS, this mapping method will maintain the same direction between each port.

[0104] In this way, a new beamforming method is proposed for large-scale MIMO selection high-rank transmission in a multi-port communication system. The gNB will only select the best beams of different halves with the same polarity to maintain the QCL principle. After multiplying the split weights in each CSI-RS port by the PMI, different layers (spatial multiplexing) will share the same CSI-RS port and maintain orthogonality to each other.

[0105] Another aspect of the present disclosure may relate to how to determine a suitable arrangement for vertical and horizontal ports. As described above, the gNB 110 can determine a set of candidate arrangements of a plurality of ports in the antenna array based on the number of the plurality of ports, and determine a target arrangement of the plurality of ports from the set of candidate arrangements. However, the gNB 110 may not be able to determine which candidate port arrangement is most suitable for the transmission between the gNB 110 and the UE 120.

[0106] Referring again to Figures 5A to 5C , Figures 5A to 5C illustrates an example of candidate port arrangements for the 8×8 mode according to some example embodiments of the present disclosure. Taking 8 CSI-RS logical ports as an example, it defines N(1,4) or N(2,2) with the same polarity. N(2,2) is easy to understand, there are 2 CSI-RS logical ports in both the vertical domain and the horizontal domain, and the gNB can separate the same assumption in the antenna physical panel, as Figure 5A shown.

[0107] But for N(1,4), the gNB has two options to separate the physical ports, as Figure 5B and Figure 5CAs shown, for different channels in a scheduling time slot, the UE can use different options to transmit data through ports. However, the gNB does not know which type is more suitable for high-layer transmission or which type has higher frequency efficiency.

[0108] In some example embodiments, the gNB 110 can use different resources to transmit detection signals through each of the candidate arrangements of multiple ports. For example, the gNB 110 can transmit a first detection signal on a first resource through multiple ports having a first candidate arrangement (e.g., as Figure 5B shown), and can transmit a second detection signal on a second resource different from the first resource through multiple ports having a second candidate arrangement (e.g., as Figure 5C shown).

[0109] After that, the gNB 110 can receive corresponding channel state information associated with different resources from the UE 110. For example, the gNB 110 can receive first channel state information associated with the first resource and second channel state information associated with the second resource. By comparing the first channel state information and the second channel state information, the gNB 110 can determine a target arrangement from the first candidate arrangement and the second candidate arrangement.

[0110] In some example embodiments, the channel state information can be referred to as channel quality information (CQI). For example, if the gNB110 determines that the first channel quality is higher than the second channel quality, the gNB 110 can determine the first candidate arrangement as the target arrangement.

[0111] In some example embodiments, the channel state information can also refer to the PMI reported by the UE. For example, the gNB 110 can determine a first candidate transmission power level for multiple ports based on the first PMI and a second candidate transmission power level for multiple ports based on the second PMI. By comparing the first candidate transmission power level with the second candidate transmission power level, the gNB110 can determine the target arrangement.

[0112] In addition, in a low-speed scenario, the arrangement of ports can be updated. For example, the channel estimated from the UEk SRS is H k , and the optimal eigenvector e k of the channel can be obtained from the SVD of the covariance matrix . According to the PMI used in data transmission, there are N types of logical port mapping relationships. For the latest data transmission, the mapping type is i latest , i latest ∈ N, and the mapping weight is

[0113] Obtain the PMI reported at power :

[0114]

[0115] Loop through all mapping types \(i\), where \(i\in N\) and \(i\neq i\). latest while maintaining the same number of layers as reported from the UE

[0116] P i =\(\sum\) Logic ports \(\sum\) layers H k w i (25)

[0117] Therefore, the strongest power with the selected combination type \(i\) best (\(i\) best \(\in N\)) and PMI can be found. The CS-IRS can be constituted by the selected type and the PMI used in the PDSCH.

[0118] In this way, the most suitable arrangement of ports can be determined, and the channel between the UE for transmission and the gNB can be reshaped, thereby improving the frequency efficiency.

[0119] In some example embodiments, an apparatus capable of performing method 200 (e.g., implemented at gNB 110) may include components for performing the corresponding steps of method 200. The components may be implemented in any suitable form. For example, the components may be implemented in circuitry or software modules.

[0120] In some example embodiments, the apparatus includes components for determining, at a base station, a target beam for carrying the transmission of a reference signal from the base station to a user equipment; components for determining a target arrangement of a plurality of ports formed at an antenna array of the base station; and components for transmitting different portions of the target beam to the user equipment via the plurality of ports based on the target arrangement.

[0121] Figure 7 is a simplified block diagram of a device 700 suitable for implementing embodiments of the present disclosure. The device 700 may be provided to implement a communication device, e.g., Figure 1 the gNB 110 as shown. As shown, the device 700 includes one or more processors 710, one or more memories 740 coupled to the processors 710, and one or more transmitters and / or receivers (TX / RX) 740 coupled to the processors 710.

[0122] The TX / RX 740 is for two-way communication. The TX / RX 740 has at least one antenna to facilitate communication. The communication interface may represent any interface necessary for communicating with other network elements.

[0123] The processor 710 can be of any type suitable for the local technical network and, by way of non-limiting example, can include one or more of the following: general-purpose computers, special-purpose computers, microprocessors, digital signal processors (DSPs), and processors based on multi-core processor architectures. The device 700 can have multiple processors, such as application specific integrated circuit chips that are subordinate in time to a clock synchronized with the main processor.

[0124] The memory 720 can include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 724, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact discs (CDs), digital video discs (DVDs), and other magnetic and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 722 and other volatile memories that do not persist during a power outage.

[0125] The computer program 730 includes computer-executable instructions that are executed by the associated processor 710. The program 730 can be stored in the ROM 720. The processor 710 can execute any suitable actions and processes by loading the program 730 into the RAM 720.

[0126] Embodiments of the present disclosure can be implemented by means of the program 730 such that the device 700 can execute any process of the present disclosure as discussed with reference to Figures 2 to 6 Embodiments of the present disclosure can also be implemented by hardware or a combination of software and hardware.

[0127] In some embodiments, the program 730 can be tangibly embodied in a computer-readable medium, which can be included in the device 700 (such as in the memory 720) or in other storage devices accessible to the device 700. The device 700 can load the program 730 from the computer-readable medium into the RAM 722 for execution. The computer-readable medium can include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. Figure 8 An example of a computer-readable medium 800 in the form of a CD or DVD is shown. The program 730 is stored on the computer-readable medium.

[0128] In general, the various embodiments of the present disclosure can be implemented using hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects can be implemented using hardware, while other aspects can be implemented using firmware or software that can be executed by a controller, a microprocessor, or other computing devices. Although the various aspects of the embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that, as a non-limiting example, the blocks, devices, systems, techniques, or methods described herein can be implemented using hardware, software, firmware, dedicated circuits or logic, general hardware or a controller or other computing devices, or some combination thereof.

[0129] 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 the instructions included in program modules, which are executed in a device on a target real or virtual processor to perform the methods 500 and 600 as described above with reference to FIGS. 5 to Figure 6 described. In general, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functions of the program modules can be combined or split as needed among the program modules. The machine-executable instructions of the program modules can be executed within a local or distributed device. In a distributed device, the program modules can be located in both local and remote storage media.

[0130] The program code for performing the methods of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a processor or a controller of a general-purpose computer, a special-purpose computer, or other programmable data processing devices, such that the program codes, when executed by the processor or the controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program codes can be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0131] In the context of the present disclosure, the computer program code or related data can be carried by any suitable carrier so that a device, apparatus, or processor can perform the various processes and operations as described above. Examples of carriers include signals, computer-readable media, etc.

[0132] A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium would include an electrical connection having one or more wires, a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0133] Moreover, although operations are described in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all shown operations be performed to obtain a desired result. In some cases, multitasking and parallel processing may be advantageous. Also, although several specific implementation details are included in the foregoing discussion, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented separately or in any suitable sub-combination in multiple embodiments.

[0134] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it is to be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the above specific features and acts are disclosed as example forms of implementing the claims.

Claims

1. A base station in a large-scale multiple-input multiple-output system, comprising: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, cause the base station to: determine a target beam for carrying the transmission of a reference signal from the base station to a user equipment, wherein the base station is caused to determine the target beam by: performing measurements on a channel for receiving a sounding reference signal from the user equipment; and determining the target beam based on the results of the measurements, wherein the target beam is configured to be mapped to a plurality of channel state information reference signal ports on the same polarity; determine a target arrangement of a plurality of ports formed at an antenna array of the base station, wherein the base station is caused to determine the target arrangement by: segmenting antennas in the antenna array along at least one of a vertical direction and a horizontal direction of the antenna array to determine a set of candidate arrangements of the plurality of ports; and determine the target arrangement of the plurality of ports from the set of candidate arrangements, from a first candidate arrangement based on first channel state information and a second candidate arrangement based on second channel state information; and transmit different parts of the target beam to the user equipment through the plurality of ports based on the target arrangement.

2. The base station according to claim 1, wherein the base station is caused to determine the target arrangement from the set of candidate arrangements by: transmitting a first detection signal to the user equipment through the plurality of ports having the first candidate arrangement in the set of candidate arrangements on a first channel; transmitting a second detection signal through the plurality of ports having the second candidate arrangement in the set of candidate arrangements on a second channel different from the first channel; and receiving, from the user equipment, the first channel state information associated with the first channel and the second channel state information associated with the second channel.

3. The base station according to claim 2, wherein the base station is caused to determine the target arrangement from the first candidate arrangement and the second candidate arrangement based on the first channel state information and the second channel state information by: Obtain a first channel quality associated with the first channel from the first channel state information; and obtaining a second channel quality associated with the second channel from the second channel state information; comparing the first channel quality with the second channel quality; and determining the first candidate arrangement as the target arrangement according to determining that the first channel quality is higher than the second channel quality.

4. The base station according to claim 2, wherein the base station is caused to determine the target arrangement from the first candidate arrangement and the second candidate arrangement based on the first channel state information and the second channel state information by: obtaining a first precoding matrix indicator associated with the first channel from the first channel state information; obtaining a second precoding matrix indicator associated with the second channel from the second channel state information; Determine the target arrangement from the set of candidate arrangements based on the first precoding matrix indicator and the second precoding matrix indicator.

5. The base station according to claim 1, wherein the base station is caused to determine the target beam by: Transmitting additional reference signals to the base station; Receiving from the user equipment an indication that the user equipment has detected the additional reference signals via a reference beam; and Determining the target beam based on the reference beam.

6. A method for a massive multiple-input multiple-output system, comprising: Determining, at a base station, a target beam for carrying a transmission of a reference signal from the base station to a user equipment, wherein determining the target beam includes: performing measurements on a channel for receiving sounding reference signals from the user equipment; and determining the target beam based on the results of the measurements, wherein the target beam is configured to be mapped to a plurality of channel state information reference signal ports on the same polarity; Determining a target arrangement of a plurality of ports formed at an antenna array of the base station, wherein determining the target arrangement includes: determining a set of candidate arrangements of the plurality of ports by segmenting antennas in the antenna array along at least one of a vertical direction and a horizontal direction of the antenna array; and determining the target arrangement of the plurality of ports from the set of candidate arrangements from a first candidate arrangement based on first channel state information and a second candidate arrangement based on second channel state information; and Transmitting different portions of the target beam to the user equipment via the plurality of ports based on the target arrangement.

7. The method according to claim 6, wherein determining the target arrangement from the set of candidate arrangements includes: Transmitting a first detection signal to the user equipment via the plurality of ports having the first candidate arrangement in the set of candidate arrangements on a first channel; Transmitting a second detection signal via the plurality of ports having the second candidate arrangement in the set of candidate arrangements on a second channel different from the first channel; and And Receiving from the user equipment the first channel state information associated with the first channel and the second channel state information associated with the second channel.

8. The method according to claim 6, wherein determining the target arrangement from the first candidate arrangement and the second candidate arrangement based on the first channel state information and the second channel state information includes: Obtaining a first channel quality associated with the first channel from the first channel state information; and And Obtaining a second channel quality associated with the second channel from the second channel state information; Comparing the first channel quality with the second channel quality; And Determining the first candidate arrangement as the target arrangement according to a determination that the first channel quality is higher than the second channel quality.

9. The method according to claim 6, wherein determining the target arrangement from the first candidate arrangement and the second candidate arrangement based on the first channel state information and the second channel state information includes: Obtain a first precoding matrix indicator associated with the first channel from the first channel state information; Obtain a second precoding matrix indicator associated with the second channel from the second channel state information; Determine the target arrangement from the set of candidate arrangements based on the first precoding matrix indicator and the second precoding matrix indicator.

10. The method according to claim 6, wherein determining the target beam comprises: Transmit an additional reference signal to the base station; Receive from the user equipment an indication that the user equipment has detected the additional reference signal via a reference beam; And Determine the target beam based on the reference beam.

11. An apparatus for a massive multiple-input multiple-output system, comprising: Components for determining, at a base station, a target beam for carrying a transmission of a reference signal from the base station to a user equipment, wherein determining the target beam comprises: performing measurements on a channel for receiving a sounding reference signal from the user equipment; and determining the target beam based on the results of the measurements, wherein the target beam is configured to be mapped to multiple channel state information reference signal ports on the same polarity; Components for determining a target arrangement of a plurality of ports formed at an antenna array of the base station, wherein determining the target arrangement comprises: determining a set of candidate arrangements of the plurality of ports by segmenting antennas in the antenna array along at least one of a vertical direction and a horizontal direction of the antenna array; and determining the target arrangement of the plurality of ports from the set of candidate arrangements from a first candidate arrangement based on first channel state information and a second candidate arrangement based on second channel state information; and Components for transmitting different portions of the target beam to the user equipment via the plurality of ports based on the target arrangement.

12. A non-transitory computer-readable medium for a massive multiple-input multiple-output system, comprising program instructions for causing an apparatus to at least execute the method according to any one of claims 6 to 10.

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