Baseband unit, method thereof and method of radio unit

Abstract

A baseband unit and methods thereof and a method of a radio unit are provided. A method by a baseband unit, the method comprising: maintaining a first physical layer; receiving a reference signal from a radio unit, wherein the radio unit is configured to maintain a second physical layer and receive signals via a plurality of antennas, the second physical layer being at a lower layer in a communication protocol than the first physical layer; performing channel estimation based on the reference signal; and sending weight information related to receive antenna weights to the radio unit, the receive antenna weights being multiplied by signals received via the plurality of antennas by the radio unit, wherein the baseband unit and the radio unit are each one of a plurality of devices constituting a base station, and wherein the baseband unit and the radio unit are physically separated and linked by an interface requiring a frequency band.

Description

[0001] This application is a divisional application of the invention patent application filed on March 14, 2018, with application number 201880019108.1 and entitled "First Communication Device, Second Communication Device, Method, Program, Recording Medium and System". Technical Field

[0002] The present invention relates to a first communication device, a second communication device, a method, a program, a recording medium, and a system. Background Technology

[0003] With the further development of mobile communications, data transmission rates are increasing at a rate higher than the expansion of available frequency bands. Therefore, beamforming using multi-element antennas has been considered as an effective technique to allow for increased data transmission rates at various frequencies. In this beamforming, the beams used for receiving (and transmitting) are formed based on channel estimates obtainable from the received signals of the individual antenna elements included in the multi-element antenna.

[0004] For example, Patent Document 1 discloses that a base station determines and performs transmit beamforming weights, and a terminal device determines and performs receive beamforming weights. For example, Patent Document 2 discloses that a terminal device determines transmit antenna weights and receive antenna weights based on reference signals from the base station and reports information related to these weights to the base station. Patent Document 3 discloses an example of a base station structure separated into a Remote Radio Unit (RRU) and a Baseband Unit (BBU).

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: WO 2016 / 152916

[0008] Patent Document 2: WO 2016 / 207929

[0009] Patent Document 3: US 2014 / 0226736A1 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] For example, as described in Patent Document 3, a base station can be separated into devices for receiving signals via antennas (e.g., RRUs) and other devices (e.g., BBUs). In this case, which device performs processes such as channel estimation, antenna weight generation, and antenna weight multiplication may affect the circuit size of that device (e.g., the RRU) and the bandwidth of the interface between the devices. However, Patent Document 3 does not discuss which device performs these processes. Therefore, the technology described in Patent Document 3 cannot reduce both the circuit size of the devices and the bandwidth of the interface between the devices.

[0012] An exemplary object of the present invention is to provide a first communication device and a second communication device that enable both the reduction of the circuit size of the device for receiving signals via an antenna and the bandwidth of the interface between the devices.

[0013] Solution for solving the problem

[0014] A first communication device according to an exemplary aspect of the present invention includes: a receiving processing unit configured to receive channel-related information relating to a channel of a signal received via a plurality of antennas from a second communication device for receiving signals via a plurality of antennas; and a transmitting processing unit configured to transmit weight information generated based on the channel-related information to the second communication device, the weight information relating to a receiving antenna weight multiplied by the signal received by the second communication device via the plurality of antennas.

[0015] A second communication device according to an exemplary aspect of the present invention includes: a radio communication processing unit configured to receive signals via a plurality of antennas; a transmission processing unit configured to transmit channel-related information relating to a channel of the signals received via the plurality of antennas to a first communication device; and a reception processing unit configured to receive from the first communication device weight information relating to receiving antenna weights, the weight information being generated based on the channel-related information, wherein the radio communication processing unit is configured to multiply the signals received via the plurality of antennas by the receiving antenna weights.

[0016] A first method according to an exemplary aspect of the invention includes: receiving channel-related information from a communication device for receiving signals via a plurality of antennas, relating to a channel of the signals received via the plurality of antennas; and sending weight information relating to receiving antenna weights to the communication device, wherein the communication device multiplies the signals received via the plurality of antennas by the receiving antenna weights, the weight information being generated based on the channel-related information.

[0017] A second method according to an exemplary aspect of the invention includes: receiving a signal via a plurality of antennas; sending channel-related information relating to a channel of the signal received via the plurality of antennas to a communication device; receiving weight information relating to receiving antenna weights from the communication device, the weight information being generated based on the channel-related information; and multiplying the signal received via the plurality of antennas by the receiving antenna weights.

[0018] A first program according to an exemplary aspect of the invention is a program configured to cause a processor to execute: receiving channel-related information from a communication device for receiving signals via a plurality of antennas, relating to a channel of signals received via the plurality of antennas; and sending weight information relating to receiving antenna weights to the communication device, wherein the communication device multiplies the signals received via the plurality of antennas by the receiving antenna weights, the weight information being generated based on the channel-related information.

[0019] A second program according to an exemplary aspect of the invention is a program for causing a processor to perform: receiving signals via a plurality of antennas; sending channel-related information to a communication device relating to the channel of the signals received via the plurality of antennas; receiving from the communication device weight information relating to receiving antenna weights, the weight information being generated based on the channel-related information; and multiplying the signals received via the plurality of antennas by the receiving antenna weights.

[0020] According to an exemplary aspect of the invention, a first recording medium is a non-transitory computer-readable recording medium containing a program for causing a processor to execute: receiving channel-related information from a communication device for receiving signals via a plurality of antennas, relating to a channel of signals received via the plurality of antennas; and sending weight information relating to receiving antenna weights to the communication device, wherein the communication device multiplies the signals received via the plurality of antennas by the receiving antenna weights, the weight information being generated based on the channel-related information.

[0021] A second recording medium according to an exemplary aspect of the invention is a non-transitory computer-readable recording medium containing a program for causing a processor to perform: receiving signals via a plurality of antennas; sending to a communication device channel-related information relating to the channels of the signals received via the plurality of antennas; receiving from the communication device weight information relating to receiving antenna weights, the weight information being generated based on the channel-related information; and multiplying the signals received via the plurality of antennas by the receiving antenna weights.

[0022] A system according to an example aspect of the present invention includes: a first communication device; and a second communication device, wherein the second communication device is configured to: receive signals via a plurality of antennas; and send channel-related information relating to a channel of the signals received via the plurality of antennas to the first communication device, the first communication device being configured to: receive the channel-related information from the second communication device; and send weight information relating to receiving antenna weights to the second communication device, the weight information being generated based on the channel-related information, and the second communication device being configured to: receive the weight information from the first communication device; and multiply the signals received via the plurality of antennas by the receiving antenna weights.

[0023] A third method according to an exemplary aspect of the invention includes: receiving signals via a plurality of antennas in a second communication device; sending channel-related information relating to a channel of the signals received via the plurality of antennas to a first communication device, wherein the channel-related information is received from the second communication device in the first communication device; sending weight information relating to receiving antenna weights to the second communication device, the weight information being generated based on the channel-related information, wherein the weight information is received from the first communication device in the second communication device; and multiplying the signals received via the plurality of antennas by the receiving antenna weights.

[0024] The effects of the invention

[0025] According to an exemplary aspect of the invention, both the circuit size of the device for receiving signals via an antenna and the bandwidth of the interface between devices can be reduced. Note that, according to an exemplary aspect of the invention, other effects can be achieved instead of or in conjunction with the above-described effects. Attached Figure Description

[0026] Figure 1 This is an illustrative diagram illustrating an example of the structure of a base station using multiple antennas;

[0027] Figure 2 This is an explanatory diagram used to illustrate the first processing layout of the base station;

[0028] Figure 3 This is an explanatory diagram illustrating the second processing layout of the base station;

[0029] Figure 4 This is an explanatory diagram illustrating an example of the schematic structure of a system according to a first exemplary embodiment;

[0030] Figure 5 This is an explanatory diagram illustrating an example of a schematic structure of a base station according to a first exemplary embodiment;

[0031] Figure 6 This is a block diagram illustrating an example of a schematic structure of a digital device according to a first exemplary embodiment;

[0032] Figure 7 This is a block diagram illustrating an example of a schematic structure of a wireless device according to a first exemplary embodiment;

[0033] Figure 8 This is an explanatory diagram illustrating a schematic example of radio communication processing in the first exemplary embodiment;

[0034] Figure 9 This is an explanatory diagram illustrating a first example of channel estimation and weight information generation in a first example embodiment;

[0035] Figure 10 This is an explanatory diagram illustrating an example of a reference signal for a first exemplary embodiment;

[0036] Figure 11 This is an explanatory diagram illustrating an example of the transmission of a reference signal in the first exemplary embodiment;

[0037] Figure 12 This is an explanatory diagram illustrating a second example of channel estimation and weight information generation for the first example embodiment;

[0038] Figure 13 This is a sequence diagram illustrating an example of a schematic flow of radio communication processing in a first exemplary embodiment;

[0039] Figure 14 This is a sequence diagram illustrating an example of a schematic flow for processing the transmission and / or reception of channel-related information and weight information according to a first exemplary embodiment;

[0040] Figure 15 This is an explanatory diagram illustrating an example of the schematic structure of a system according to a second exemplary embodiment;

[0041] Figure 16 This is a block diagram illustrating an example of the schematic structure of a first communication device according to a second exemplary embodiment; and

[0042] Figure 17 This is a block diagram illustrating an example of the schematic structure of a second communication device according to a second exemplary embodiment. Detailed Implementation

[0043] The following description will detail exemplary embodiments of the present invention with reference to the accompanying drawings. Note that in this specification and the drawings, elements to which similar descriptions apply are indicated by the same reference numerals, thereby omitting redundant descriptions.

[0044] The explanations will be given in the following order.

[0045] 1. Related Technologies

[0046] 2. Overview of the Example Implementation

[0047] 3. First Example Implementation

[0048] 3.1. System Structure

[0049] 3.2. Structure of Digital Devices

[0050] 3.3. Structure of Radio Equipment

[0051] 3.4. Technical Features

[0052] 3.5. Variations

[0053] 4. Second Example Implementation

[0054] 4.1. System Structure

[0055] 4.2. Structure of the First Radio Equipment

[0056] 4.3. Structure of the Second Radio Equipment

[0057] 4.4. Technical Features

[0058] <<1. Related Technologies>

[0059] First, refer to Figures 1-3 This is to illustrate the relevant technology. Of course, it should be noted that the relevant technology described herein may also be included in the exemplary embodiments of the present invention.

[0060] - An example of a base station structure using multiple antennas

[0061] Figure 1 This is an explanatory diagram illustrating an example of the structure of a base station 50 using multiple antennas.

[0062] --Receive Processing

[0063] The radio received signals (N-series radio received signals) from the N antenna elements 51 included in the multi-element antenna are converted into N-series received baseband signals on the time axis by the transmit and / or receive unit (TRX) 53, and further converted into N-series received signals on the frequency axis by the Fast Fourier Transform (FFT) unit 55. Furthermore, the N-series received signals are multiplied by a receive antenna weight matrix having M rows and N columns by the antenna weight multiplication unit 57. As a result, M-series received signals (i.e., M-layer received signals) are output. The M-series received signals are demodulated by the demodulation unit (DEM) 59 and further decoded by the decoding unit (DEC) 61.

[0064] The channel estimation unit (ChEst) 63 performs channel estimation based on the reference signal included in the N-series received signal, which is the output of the FFT unit 55. In this way, an N-series channel estimate is generated and then output. Furthermore, the antenna weight generation unit 65 generates a receive antenna weight matrix with M rows and N columns based on the N-series channel estimate. Then, as described above, the receive antenna weight matrix is ​​used by the antenna weight multiplication unit 57. Note that the antenna weight generation unit 65 can also generate a transmit antenna weight matrix with N rows and L columns based on the N-series channel estimate.

[0065] --Send processing

[0066] The transmitted signal is first encoded by the coding unit (COD) 71 and then modulated by the modulation unit (MOD) 73. As a result, the transmitted signal becomes an L-series transmitted signal (L-layer transmitted signal). The L-series transmitted signal is multiplied by the antenna weight multiplication unit 75 by a transmitted antenna weight matrix with N rows and L columns to become an N-series transmitted signal on the frequency axis. This N-series transmitted signal on the frequency axis is converted into an N-series baseband signal on the time axis by the inverse fast Fourier transform (IFFT) unit 77, and further converted into an N-series radio transmitted signal by the transmit and / or receive unit 53. Then, this N-series radio transmitted signal is transmitted from the N antenna elements included in the multi-element antenna.

[0067] Processing layout in base stations

[0068] In practical implementation, for example, Figure 1 In the example, base station 50 is divided into wireless equipment including a transmitting and / or receiving unit 53, and digital equipment including a demodulation unit 59, a decoding unit 61, an encoding unit 71, and a modulation unit 73. For example, the wireless equipment is arranged adjacent to the multi-antenna array, the digital equipment is arranged indoors within the station, and the wireless equipment and digital equipment are connected to each other via fiber optic cables.

[0069] Here, we consider the case where the antenna weight multiplication units 57 and 75 and the antenna weight generation unit 65 are arranged in a digital device (first processing arrangement case), and the case where the antenna weight multiplication units 57 and 75 and the antenna weight generation unit 65 are arranged in a wireless device (second processing arrangement case).

[0070] --First processing layout

[0071] Figure 2 This is an explanatory diagram illustrating the first processing arrangement of base station 50. In this example, the antenna weight multiplication units 57 and 75, the channel estimation unit 63, and the antenna weight generation unit 65 are arranged in digital device 90, rather than in radio device 80.

[0072] In the first processing arrangement, the circuitry of the radio device 80 is small, making it relatively easy to reduce its size and weight. However, in this case, an interface (i.e., N interfaces) is needed between the radio device 80 and the digital device 90 for receiving and transmitting N series signals, respectively. Therefore, with a very large number of antenna elements N, a very large bandwidth is required between the radio device 80 and the digital device 90.

[0073] --Second processing layout

[0074] Figure 3 This is an explanatory diagram illustrating the second processing arrangement of base station 50. In this example, the antenna weight multiplication units 57 and 75, the channel estimation unit 63, and the antenna weight generation unit 65 are arranged in the radio equipment 80, rather than in the digital equipment 90.

[0075] In the second processing arrangement, only interfaces (i.e., M interfaces) are needed between the radio device 80 and the digital device 90 for receiving M-series signals and for transmitting L-series signals (i.e., L interfaces). Therefore, even with a very large number of antenna elements N, a relatively small bandwidth is not required between the radio device 80 and the digital device 90. However, channel estimation and antenna weight generation (especially the latter) are complex and specialized processes. Consequently, the circuitry of the radio device 80 increases, hindering reductions in its size and weight. Furthermore, channel estimation and antenna weight generation are processes performed for each user (terminal device), therefore the radio device 80 needs to consider the user (terminal device) during processing.

[0076] In view of the above, it is desirable to reduce both the circuit size of the device (wireless device) used to receive signals via an antenna and the bandwidth of the interface between devices (interface between wireless device and digital device).

[0077] <<2. Overview of Example Implementations>>

[0078] In an exemplary embodiment of the present invention (hereinafter referred to as this exemplary embodiment), the wireless device receives signals via multiple antennas (e.g., multiple antenna elements included in an array antenna). Furthermore, particularly in this exemplary embodiment, the wireless device multiplies the signals received via the multiple antennas by the receiving antenna weights.

[0079] Furthermore, particularly in this example embodiment, the wireless device transmits channel-related information concerning the channel of the signal received via multiple antennas to the digital device. The digital device receives this channel-related information. Then, based on this channel-related information, it generates weight information related to the receiving antenna weights. The digital device then transmits this weight information to the wireless device. The wireless device receives this weight information. Afterward, the wireless device multiplies the signal received via the multiple antennas by the receiving antenna weights.

[0080] In this way, for example, both the circuit size of the wireless equipment and the frequency band of the interface between the wireless equipment and the digital equipment can be reduced.

[0081] Note that the above technical features are specific examples of this exemplary embodiment, and obviously this exemplary embodiment is not limited to the above technical features.

[0082] <<3. First Example Implementation>>

[0083] Next, refer to Figures 4 to 13 The first exemplary embodiment of the present invention will be described below.

[0084] <3.1. System Structure>

[0085] First, refer to Figure 4 and Figure 5 An example illustrating the structure of system 1 according to the first example embodiment. Figure 4 This is an explanatory diagram illustrating an example of the schematic structure of system 1 according to a first exemplary embodiment. (Refer to...) Figure 4 System 1 includes base station 10 and terminal equipment 40.

[0086] For example, System 1 is a system compliant with the 3rd Generation Partnership Project (3GPP) standards. More specifically, System 1 may be a system compliant with LTE / LTE Advanced and / or System Architecture Evolution (SAE). Optionally, System 1 may be a system compliant with fifth-generation (5G) standards. Of course, System 1 is not limited to these examples.

[0087] (1) Base station 10

[0088] Base station 10 is a node of the radio access network (RAN) and communicates radio with terminal devices (e.g., terminal device 40) located in the coverage area.

[0089] -Specific examples of base station 10

[0090] Base station 10 is a node that conducts radio communication with terminal equipment, i.e., a node of the radio access network (RAN). For example, base station 10 may be an evolved Node B (eNB) or a Generating Node B (gNB) in 5G. Base station 10 may include multiple units (or multiple nodes). These multiple units (or multiple nodes) may include a first unit (or first node) that performs processing at a higher protocol layer and a second unit (or second node) that performs processing at a lower protocol layer. As an example, the first unit may be referred to as a central unit (CU), and the second unit may be referred to as a distributed unit (DU) or access unit (AU). As another example, the first unit may be referred to as a digital unit (DU), and the second unit may be referred to as a radio unit (RU) or remote unit (RU). The digital unit (DU) may be a baseband unit (BBU), and the RU may be a remote radio head (RRH) or a remote radio unit (RRU). Of course, the terms first unit (or first node) and second unit (or second node) are not limited to these examples. Optionally, base station 10 may be a single unit (or a single node). In this case, base station 10 can be one of multiple units (e.g., the second unit) and can be connected to other units (e.g., the first unit) among the multiple units.

[0091] - Structure of base station 10

[0092] Figure 5 This is an explanatory diagram illustrating an example of the schematic structure of a base station 10 according to a first exemplary embodiment. (See reference...) Figure 5 Base station 10 includes digital equipment 100, wireless equipment 200, and multiple antennas 300. For example, base station 10 includes N antennas 300.

[0093] --Digital devices 100 and wireless devices 200

[0094] Digital device 100 and radio device 200 are each among a plurality of devices constituting base station 10. Base station 10 may also include other devices (not shown) besides digital device 100 and radio device 200 (and a plurality of antennas 300).

[0095] Wireless device 200 is physically separate from digital device 100. Wireless device 200 is connected to multiple antennas 300. Digital device 100 is connected to wireless device 200. Digital device 100 and wireless device 200 are connected to each other via communication line 21. Digital device 100 receives information from wireless device 200 via communication line 21 and transmits information to wireless device 200 via communication line 21. For example, communication line 21 is a fiber optic line. For example, digital device 100 is located indoors, and wireless device 200 is located outdoors.

[0096] In the case where base station 10 includes a first unit and a second unit as described above, digital device 100 may be the first unit (e.g., a digital unit (DU) or a BBU), and radio device 200 may be the second unit (e.g., a remote / radio unit (RU), RRH, or RRU). Optionally, digital device 100 and radio device 200 may be devices included in the second unit (e.g., a distributed unit (DU)).

[0097] Note that since digital device 100 processes digital signals, it is referred to as a digital device. However, more generally, digital device 100 may be referred to as a communication device. Since radio device 200 processes radio signals, as will be explained later, it is referred to as a radio device. However, more generally, radio device 200 may be referred to as a communication device. Of course, radio device 200 can process both digital signals and radio signals. Here, for a better understanding of the first example embodiment, the terms "digital device" and "radio device" are used instead of "communication device".

[0098] --Multiple antennas 300

[0099] For example, each of the multiple antennas 300 is an antenna element included in a multi-element antenna. For example, a multi-element antenna is an antenna used in massive MIMO (Multi-Input Multiple-Output) systems.

[0100] (2) Terminal equipment 40

[0101] Terminal device 40 communicates radio with base station 10. For example, when terminal device 40 is located within the coverage area of ​​base station 10, terminal device 40 communicates radio with base station 10. For example, terminal device 40 may be referred to as user equipment (UE), user terminal, or mobile station.

[0102] Figure 4 This example shows only one terminal device 40. However, of course, multiple terminal devices 40 can exist.

[0103] <3.2. Structure of Digital Devices>

[0104] Next, refer to Figure 6 This is an example illustrating the structure of a digital device 100 according to a first example embodiment. Figure 6 This is a block diagram illustrating an example of the schematic structure of a digital device 100 according to a first exemplary embodiment. (See reference...) Figure 6 The digital device 100 includes an interface 110, a storage unit 120, and a processing unit 130.

[0105] (1) Interface 110

[0106] Interface 110 is the interface used for communication with wireless device 200. In other words, interface 110 is the interface used for the communication line 21 (e.g., fiber optic line) connecting digital device 100 and wireless device 200. Through interface 110, signals from wireless device 200 are received, and signals are sent to wireless device 200.

[0107] (2) Storage unit 120

[0108] Storage unit 120 temporarily or permanently stores the program (instructions) and parameters used for the operation of digital device 100, as well as various data. The program includes one or more instructions used for the operation of digital device 100.

[0109] (3) Processing unit 130

[0110] Processing unit 130 provides various functions of digital device 100. Processing unit 130 includes radio communication processing unit 131, receiving processing unit 133, generating unit 135, and transmitting processing unit 137. Note that processing unit 130 may also include other components besides these. Specifically, processing unit 130 can also perform operations other than those of these components. The specific operations of radio communication processing unit 131, receiving processing unit 133, generating unit 135, and transmitting processing unit 137 will be described in detail later.

[0111] For example, the processing unit 130 communicates with the wireless device 200 via the interface 110.

[0112] (4) Implementation Example

[0113] Interface 110 can be implemented using a converter (e.g., an optical-to-electrical (O / E) converter and / or an electrical-to-optical (E / O) converter). Storage unit 120 can be implemented using memory (e.g., non-volatile memory and / or volatile memory) and / or a hard disk. Processing unit 130 can be implemented using one or more processors, such as a baseband (BB) processor and / or other types of processors. Radio communication processing unit 131, receiving processing unit 133, generating unit 135, and transmitting processing unit 137 can be implemented using the same processor, or they can be implemented using separate processors. Memory (storage unit 120) can be included in one or more processors, or it can be located external to one or more processors.

[0114] Digital device 100 may include a memory storing a program (instructions) and one or more processors capable of executing the program (instructions). The one or more processors may execute the program to perform operations of processing unit 130 (operations of radio communication processing unit 131, receiving processing unit 133, generating unit 135, and / or transmitting processing unit 137). The program may be a program for causing the processor to perform the operations of processing unit 130 (operations of radio communication processing unit 131, receiving processing unit 133, generating unit 135, and / or transmitting processing unit 137).

[0115] <3.3. Structure of Radio Equipment>

[0116] Next, refer to Figure 7 An example illustrating the structure of the wireless device 200 according to the first example embodiment. Figure 7 This is a block diagram illustrating an example of the schematic structure of a wireless device 200 according to a first exemplary embodiment. (See reference...) Figure 7 The wireless device 200 includes a first interface 210, a second interface 220, a storage unit 230, and a processing unit 240.

[0117] (1) First interface 210

[0118] The first interface 210 is an interface used for radio communication via multiple antennas 300. The first interface 210 receives radio signals from and transmits radio signals to the multiple antennas 300.

[0119] (2) Second interface 220

[0120] The second interface 220 is the interface used for communication with the digital device 100. In other words, the second interface 220 is the interface used for the communication line 21 (e.g., fiber optic line) connecting the digital device 100 and the radio device 200. The second interface 220 receives signals from the digital device 100 and sends signals to the digital device 100.

[0121] (3) Storage unit 230

[0122] Storage unit 230 temporarily or permanently stores the programs (instructions) and parameters used for the operation of radio device 200, as well as various data. The program includes one or more instructions used for the operation of radio device 200.

[0123] (4) Processing unit 240

[0124] Processing unit 240 provides various functions of wireless device 200. Processing unit 240 includes radio communication processing unit 241, transmitting processing unit 243, and receiving processing unit 245. Note that processing unit 240 may also include other components besides these. In other words, processing unit 240 can also perform operations other than those of these components. The specific operations of radio communication processing unit 241, transmitting processing unit 243, and receiving processing unit 245 will be described in detail later.

[0125] For example, processing unit 240 communicates with digital device 100 via second interface 220. Processing unit 240 (radio communication processing unit 241) transmits and / or receives radio signals via first interface 210 (thereby via multiple antennas 300).

[0126] (5) Implementation Example

[0127] The first interface 210 can be implemented using radio frequency (RF) circuitry or an A / D converter, etc. The second interface 220 can be implemented using a converter (e.g., an O / E converter and / or an E / O converter), etc. The storage unit 230 can be implemented using a memory (e.g., non-volatile memory and / or volatile memory) and / or a hard disk, etc. The processing unit 240 can be implemented using one or more processors, such as a BB processor and / or other types of processors. The radio communication processing unit 241, the transmitting processing unit 243, and the receiving processing unit 245 can be implemented using the same processor, or they can be implemented using separate processors. The memory (storage unit 230) can be included in one or more processors, or it can be located outside one or more processors.

[0128] The wireless device 200 may include a memory storing a program (instructions) and one or more processors capable of executing the program (instructions). The one or more processors may execute the program to perform operations of the processing unit 240 (operations of the radio communication processing unit 241, the transmitting processing unit 243, and / or the receiving processing unit 245). The program may be a program for causing the processor to perform the operations of the processing unit 240 (operations of the radio communication processing unit 241, the transmitting processing unit 243, and / or the receiving processing unit 245).

[0129] <3.4. Technical Features>

[0130] Next, refer to Figures 8 to 14 The technical features of the first example embodiment will be explained.

[0131] (1) Radio communication processing

[0132] -Receive processing

[0133] Radio device 200 (first interface 210 and radio communication processing unit 241) receives signals via multiple antennas 300. Furthermore, particularly in the first example embodiment, radio device 200 (radio communication processing unit 241) multiplies the signals received via the multiple antennas 300 by receiving antenna weights. For example, receiving antenna weights can also be referred to as (received) beamforming weights (i.e., weights used for beamforming on the receiving side).

[0134] For example, digital device 100 (radio communication processing unit 131) demodulates and decodes signals of one or more layers generated by multiplying signals received via multiple antennas 300 by receiving antenna weights through radio device 200.

[0135] Reference Figure 8 This is an example illustrating the receiving processing of digital device 100 and radio device 200. Figure 8 This is an explanatory diagram illustrating a schematic example of radio communication processing in a first exemplary embodiment.

[0136] The radio device 200 (transmitting and / or receiving unit 401) converts the radio received signals (N-series radio received signals) from multiple antennas 300 (N antennas 300) into N-series received baseband signals on the time axis. Then, the radio device 200 (FFT unit 403) converts the N-series received baseband signals on the time axis into N-series received signals on the frequency axis using FFT. Furthermore, the radio device 200 (antenna weight multiplication unit 405) multiplies the N-series received signals on the frequency axis by a received antenna weight matrix with M rows and N columns (a vector when M is 1). As a result, an M-series received signal (i.e., M-layer received signal) is output for transmission to the digital device 100.

[0137] For example, as described above, the signal to be transmitted from the radio device 200 to the digital device 100 is not an N-series received signal, but an M-series received signal (M-layer received signal). Therefore, even as the number of antennas N increases, the bandwidth of the interface between the digital device 100 and the radio device 200 can be small.

[0138] Digital device 100 (demodulation unit 407 and decoding unit 409) demodulates the received M-series signal (i.e., the received signal at layer M) and decodes the demodulated received signal. For example, the decoded information is sent from digital device 100 to other devices for processing. Optionally, the decoded information can be further processed by digital device 100.

[0139] Note, for example, Figure 8 The transmitting and / or receiving unit 401 includes Figure 7 In the first interface 210, and Figure 8 The FFT unit 403 and the antenna weight multiplication unit 405 are included in Figure 7 In the radio communication processing unit 241. For example, Figure 8 The demodulation unit 407 and the decoding unit 409 include Figure 6 In the radio communication processing unit 131.

[0140] For example, as described above, digital device 100 and radio device 200 perform physical layer (also known as layer 1) reception processing. Specifically, radio device 200 performs a portion of the physical layer reception processing, and digital device 100 performs the remainder of the physical layer reception processing.

[0141] -Send processing

[0142] For example, digital device 100 (radio communication processing unit 131) encodes and modulates signals to generate signals with more than one layer.

[0143] For example, particularly in the first example embodiment, the radio device 200 (radio communication processing unit 241) multiplies the signal of more than one layer by the transmit antenna weights. Furthermore, the radio device 200 (first interface 210 and radio communication processing unit 241) transmits the signal generated by multiplying by the transmit antenna weights via multiple antennas 300. For example, the transmit antenna weights may also be referred to as (transmit) beamforming weights (i.e., weights used for beamforming on the transmit side).

[0144] Refer again Figure 8 The digital device 100 (encoding unit 421 and modulation unit 423) encodes the transmitted signal and modulates the encoded transmitted signal. As a result, it outputs an L-series transmitted signal (L-layer transmitted signal) for transmission to the radio device 200.

[0145] Radio device 200 (antenna weight multiplication unit 425) multiplies the L-series transmitted signal by a transmitted antenna weight matrix having N rows and L columns, thereby generating an N-series transmitted signal on the frequency axis. Then, radio device 200 (IFFT unit 427) converts the N-series transmitted signal on the frequency axis into an N-series baseband signal on the time axis using IFFT. Furthermore, radio device 200 (transmit and / or receive unit 401) converts the N-series baseband signal on the time axis into an N-series radio transmitted signal. The N-series radio transmitted signal is then transmitted from multiple antennas 300 (N antennas 300).

[0146] For example, as described above, the signal to be transmitted from digital device 100 to radio device 200 is not an N-series received signal, but an L-series received signal (L-layer received signal). Therefore, even as the number of antennas N increases, the bandwidth of the interface between digital device 100 and radio device 200 can be small.

[0147] Note, for example, Figure 8 The encoding unit 421 and modulation unit 423 include Figure 6 In the radio communication processing unit 131. For example, Figure 8 The antenna weight multiplication unit 425 and IFFT unit 427 are included in Figure 7 In the radio communication processing unit 241, and Figure 8 The transmitting and / or receiving unit 401 includes Figure 7 In the first interface 210.

[0148] For example, as described above, digital device 100 and radio device 200 perform physical layer (also known as layer 1) transmission processing. Specifically, radio device 200 performs a portion of the physical layer transmission processing, and digital device 100 performs the remainder of the physical layer transmission processing.

[0149] (2) Receiving antenna weight

[0150] Specifically, in the first example embodiment, the radio device 200 (transmitting processing unit 243) transmits channel-related information relating to the channel of signals received via the plurality of antennas 300 to the digital device 100. The digital device 100 (receiving processing unit 133) receives the channel-related information from the radio device 200.

[0151] For example, digital device 100 (generating unit 135) generates weight information related to the weight of the receiving antenna based on channel-related information.

[0152] Furthermore, the digital device 100 (transmitting processing unit 137) transmits the weight information to the radio device 200. The radio device 200 (receiving processing unit 245) receives the weight information from the digital device 100.

[0153] Then, the wireless device 200 (radio communication processing unit 241) multiplies the signal received via multiple antennas 300 by the receiving antenna weight.

[0154] (2-1) Signal

[0155] The signals received by the multiple antennas 300 are uplink signals (i.e., signals sent from the terminal device 40 to the base station 10).

[0156] (2-2) Channel-related information

[0157] -channel

[0158] For example, a channel is a channel between terminal device 40 and multiple antennas 300.

[0159] -First Example: Reference Signal

[0160] For example, channel-related information is a reference signal received via multiple antennas 300. Specifically, the radio device 200 (transmission processing unit 243) transmits this reference signal to the digital device 100. The reference signal is information to be used for channel estimation.

[0161] In this scenario, the digital device 100 (generation unit 135) performs channel estimation based on the reference signal to calculate the channel estimate. Then, the digital device 100 (generation unit 135) generates weighting information based on the channel estimate.

[0162] Reference Figure 9 This is the first example to illustrate channel estimation and weight information generation. Figure 9 This is an illustrative diagram used to explain a first example of channel estimation and weight information generation in a first example embodiment. (Reference) Figure 9 The radio device 200 (transmit processing unit 243) transmits the reference signal (N-series reference signal) of the output of the FFT unit 403 (the N-series received signal on the frequency axis) to the digital device 100. The digital device 100 (receive processing unit 133) receives these reference signals. Then, the digital device 100 (channel estimation unit 411: generation unit 135) performs channel estimation based on the reference signals to calculate the channel estimate (N-series channel estimate). In addition, the digital device 100 (antenna weight generation unit 413: generation unit 135) calculates the receive antenna weights (a receive antenna weight matrix with M rows and N columns) based on the channel estimate to generate weight information related to the receive antenna weights. The digital device 100 (transmit processing unit 137) transmits this weight information to the radio device 200. The radio device 200 (receive processing unit 245) receives this weight information. Subsequently, the radio device 200 (radio communication processing unit 241) sets the receiving antenna weights to be used for multiplying the signals received via the multiple antennas 300. This configuration enables the radio device 200 (radio communication processing unit 241) to multiply the signals received via the multiple antennas 300 by the receiving antenna weights.

[0163] According to this example, neither the channel estimation unit 411 nor the antenna weight generation unit 413 is included in the radio device 200; instead, both the channel estimation unit 411 and the antenna weight generation unit 413 are included in the digital device 100. Therefore, the circuit size of the radio device 200 can be further reduced.

[0164] For example, a reference signal is a reference signal transmitted within a specific time period in a time frame. Figure 10 This is an explanatory diagram illustrating an example of a reference signal used to illustrate a first exemplary embodiment. (Reference) Figure 10 This illustrates one of the repeating time frames 1001 and a specific time period 1003 within a time frame 1001. For example, a reference signal 1011 is transmitted during the specific time period 1003. For example, the signal pattern of the reference signal 1011 is constant throughout the frequency band, thus each user (each terminal device) transmits the reference signal in its allocated frequency band throughout the entire frequency band. For example, this configuration facilitates the transmission of reference signals from the radio device 200 to the digital device 100. More specifically, for example, even if the radio device 200 does not maintain information about each user (terminal device), the radio device 200 can extract only the reference signals from the received signals and can transmit these reference signals to the digital device 100. Note, for example, as... Figure 10 As shown, the specific time period 1003 is located at the end of time frame 1001. However, the position of the specific time period 1003 is not limited to this example. For example, the specific time period 1003 can be located at the beginning of time frame 1001, or it can be located at a position other than the beginning and end of time frame 1001. The specific time period 1003 can be as follows: Figure 10 It can be a continuous time period, or it can be two or more dispersed time periods.

[0165] As an example, a time frame is a radio frame, and a specific time period is a specific symbol. Specifically, a reference signal is transmitted within a specific symbol in the radio frame. Note that, for example, a radio frame may consist of a predetermined number of subframes, and a subframe may consist of a predetermined number of symbols. Note that time frames and specific time periods are not limited to this example.

[0166] For example, the reference signal is a probe reference signal (SRS). Alternatively, the reference signal can be a demodulation reference signal (DMRS).

[0167] Note that base station 10 (digital device 100 and radio device 200) can perform time-division duplex (TDD) communication. In this case, for example, as Figure 11As shown, reference signal 1011 can be transmitted from wireless device 200 to digital device 100. Specifically, wireless device 200 receives reference signal 1011 and other signals 1013 (such as data signals and control signals) as radio received signals during reception period 1021 (i.e., uplink period), while wireless device 200 does not receive signals during transmission period 1023 (i.e., downlink period). Therefore, as Figure 11 As shown, for example, wireless device 200 may transmit other signals (M-series signals) to digital device 100 during reception period 1021, and may transmit reference signals (N-series signals) to digital device 100 during subsequent transmission period 1023 (and a portion of reception period 1021).

[0168] - Second example: Channel estimation

[0169] Channel-related information can be channel estimates calculated by the radio device 200 based on channel estimation of reference signals received via multiple antennas 300. Specifically, the radio device 200 can perform channel estimation based on the reference signals to calculate channel estimates and transmit these channel estimates to the digital device 100.

[0170] Reference Figure 12 This is a second example illustrating channel estimation and weight information generation. Figure 12 This is an illustrative diagram illustrating a second example of channel estimation and weight information generation used to explain the first example embodiment. (Reference) Figure 12 The radio device 200 (channel estimation unit 411: radio communication processing unit 241) performs channel estimation based on the reference signal (N-series reference signal) of the output of the FFT unit 403 (N-series received signal on the frequency axis) to calculate channel estimation values ​​(N-series channel estimation values). Then, the radio device 200 (transmit processing unit 243) transmits these channel estimation values ​​to the digital device 100. The digital device 100 (receive processing unit 133) receives these channel estimation values. Furthermore, the digital device 100 (antenna weight generation unit 413: generation unit 135) calculates the receive antenna weights (a receive antenna weight matrix with M rows and N columns) based on the channel estimation values ​​to generate weight information related to the receive antenna weights. Subsequent processing and... Figure 9 The processing is the same as in the example, so a repeated explanation of this processing is omitted here.

[0171] According to this example, the content to be transmitted from radio device 200 to digital device 100 is not the reference signal itself, but a channel estimate. For example, the amount of data in the channel estimate can be compressed by averaging the channel estimate on the frequency axis. Therefore, the bandwidth of the interface between radio device 200 and digital device 100 can be further reduced.

[0172] (2-3) Weight Information

[0173] As mentioned above, the weight information is weight information related to the weight of the receiving antenna. For example, the weight information is information indicating the weight of the receiving antenna.

[0174] Furthermore, as mentioned above, the receiving antenna weight is the weight by which the wireless device 200 multiplies the signals received via multiple antennas 300. For example, the receiving antenna weight is the weight by which the wireless device 200 multiplies the signals received from the terminal device 40 via multiple antennas.

[0175] For example, as mentioned above, the receive antenna weights are receive antenna weight matrices with M rows and N columns (a vector when M is 1). In this case, the weight information is information indicating the receive antenna weight matrix with M rows and N columns.

[0176] As a first example, the weight information includes information indicating the individual weights included in the receive antenna weights. Specifically, for example, the receive antenna weights are a receive antenna weight matrix with M rows and N columns, and the weight information includes information indicating the individual elements (weights) included in the receive antenna weight matrix. Specifically, the weight information includes information indicating the individual elements among the M×N elements. For example, this configuration allows for more flexible setting of the receive antenna weights.

[0177] As a second example, the receive antenna weight can be one of a plurality of predetermined receive antenna weight sets, and the weight information can be an index indicating that receive antenna weight set. Specifically, for example, a plurality of receive antenna weight sets and an index indicating each receive antenna weight set in these plurality of receive antenna weight sets can be predefined as a codebook, and the weight information can be an index indicating a receive antenna weight set in the codebook. For example, this configuration further reduces the amount of information in the weight information.

[0178] (2-4) Information related to the use of receiver antenna weighting

[0179] For example, digital device 100 (transmission processing unit 137) transmits weight information and information related to the use of the receiving antenna weights (hereinafter referred to as "usage information") to radio device 200. For example, this configuration enables radio device 200 to actually perform the multiplication of the receiving antenna weights.

[0180] -Frequency Information

[0181] For example, the information used includes frequency information related to the frequency used for receiving antenna weighting. For example, the frequency used for receiving antenna weighting is the frequency assigned to terminal device 40. Specifically, the frequency information is information related to the frequency assigned to terminal device 40.

[0182] For example, frequency information indicates a frequency block among multiple frequency blocks that uses receive antenna weights. In other words, frequency information indicates the frequency block from which the signal to be transmitted is multiplied by multiple antenna weights. Frequency information can indicate a single frequency block or multiple frequency blocks. For example, a frequency block is a resource block (or a group of resource blocks).

[0183] Additionally, or optionally, the frequency information may indicate the frequency resolution of the receiving antenna weights. In other words, the frequency information may indicate the width (per unit width) of the frequencies used for the receiving antenna weights.

[0184] For example, such frequency information as described above enables the radio device 200 to be notified of the signals that the receiving antenna weights need to be multiplied by, and the frequencies at which these signals are transmitted.

[0185] -Time Information

[0186] For example, the usage information includes time information related to the time for using the receive antenna weights. For example, the time for using the receive antenna weights is the time allocated to the terminal device 40. Specifically, the time information is information related to the time allocated to the terminal device 40.

[0187] For example, timing information indicates the time period during which receive antenna weights are used. In other words, timing information indicates the time period during which signals to be multiplied by multiple antenna weights are transmitted. This time period can be a subframe or a time slot. However, the time period is not limited to these examples.

[0188] For example, such timing information as described above enables the radio device 200 to be notified of the signals that the receiving antenna weights need to be multiplied by, and the time to transmit these signals.

[0189] Frequency information and time information can be radio resource information (also known as resource allocation information or scheduling information) related to radio resources using received antenna weights.

[0190] As described above, radio device 200 transmits channel-related information to digital device 100. Digital device 100 generates weight information related to the receiving antenna weights based on this channel-related information and transmits this weight information to radio device 200. Radio device 200 then multiplies the signals received via multiple antennas 300 by the receiving antenna weights. In this way, the generation of weight information (the calculation of the receiving antenna weights) is performed by digital device 100, not by radio device 200. Therefore, the circuitry of radio device 200 can be miniaturized.

[0191] (3) Processing flow

[0192] - Radio communication processing

[0193] Reference Figure 13 This example illustrates a radio communication process according to a first exemplary embodiment. Figure 13 This is a sequence diagram illustrating an example of a schematic flow of radio communication processing according to a first exemplary embodiment.

[0194] The wireless device 200 receives signals via multiple antennas 300 (S501).

[0195] The wireless device 200 multiplies the signals received via multiple antennas 300 by the receiving antenna weights (S503). In this way, for example, signals of more than one layer are generated.

[0196] The wireless device 200 transmits the signals of the one or more layers to the digital device 100 (S505).

[0197] Digital device 100 demodulates and decodes signals from one or more layers (S507).

[0198] - Transmission and / or reception of channel-related and weight information

[0199] Reference Figure 14 This example illustrates the processing of sending and / or receiving channel-related information and weight information according to the first exemplary embodiment. Figure 14 This is a sequence diagram illustrating an example of a schematic flow for processing the transmission and / or reception of channel-related information and weight information according to a first example embodiment.

[0200] The wireless device 200 receives signals via multiple antennas 300 (S521).

[0201] The radio device 200 transmits channel-related information relating to the channel of signals received via multiple antennas 300 to the digital device 100, and the digital device 100 receives the channel-related information (S523).

[0202] Digital device 100 generates weight information related to the weight of the receiving antenna based on channel-related information (S525).

[0203] Digital device 100 sends weight information to radio device 200, and radio device 200 receives the weight information (S527).

[0204] The radio device 200 sets the receiving antenna weights to be used for multiplying the signals received via the multiple antennas 300 (S529).

[0205] <3.5. Variations>

[0206] As described above, in the first example embodiment, digital device 100 (transmitting processing unit 137) transmits weight information relating to the receiving antenna weights by which signals received by radio device 200 via multiple antennas 300 are multiplied. Radio device 200 (receiving processing unit 245) receives this weight information from digital device 100.

[0207] -First Example

[0208] In a variation of the first example embodiment, for example, digital device 100 (transmitting processing unit 137) may also transmit additional weight information relating to the transmit antenna weights used by radio device 200 to generate a signal to be transmitted via the plurality of antennas 300. Radio device 200 (receiving processing unit 245) can then receive such additional weight information from digital device 100. For example, digital device 100 (generating unit 135) may generate such additional weight information based on channel-related information.

[0209] The transmit antenna weights can be a transmit antenna weight matrix with N rows and L columns (a vector when L is 1).

[0210] This other weight information related to the transmit antenna weight can be information in the same format as the weight information related to the receive antenna weight.

[0211] The radio device 200 (radio communication processing unit 241) can set the transmit antenna weights based on such other weight information. Then, the radio device 200 (radio communication processing unit 241) can multiply the signals of more than one layer (e.g., signals of layer L) by the transmit antenna weights, thereby generating signals to be transmitted via multiple antennas 300.

[0212] -Second Example

[0213] Optionally, the receive antenna weights can be the same antenna weights used by the radio device 200 to generate signals to be transmitted via multiple antennas. Specifically, the receive antenna weights and transmit antenna weights can be the same. For example, when the number of transmit layers L and the number of receive layers M are the same, as described above, the receive antenna weights and transmit antenna weights can be the same.

[0214] In both the first and second examples, especially in the variant of the first example, base station 10 (digital device 100 and radio device 200) can perform TDD-style communication.

[0215] The first exemplary embodiment has been described above. According to the first exemplary embodiment, both the circuit size of the wireless device 200 and the frequency band of the interface between the wireless device 200 and the digital device 100 can be small.

[0216] <<4. Second Example Implementation>

[0217] Next, refer to Figures 15-17 The second exemplary embodiment of the present invention will be described below. The first exemplary embodiment described above is a specific exemplary embodiment, while the second exemplary embodiment is a more generalized exemplary embodiment.

[0218] <4.1. System Structure>

[0219] First, refer to Figure 15 This is an example illustrating the structure of system 2 according to the second example embodiment. Figure 15 This is an explanatory diagram illustrating an example of the schematic structure of system 2 according to the second exemplary embodiment. (Refer to...) Figure 15 System 2 includes a first communication device 600, a second communication device 700, and multiple antennas 800.

[0220] For example, system 2 is a base station. For example, the description of the base station is the same as that of base station 10 in the first example embodiment. Therefore, repeated descriptions of the base station are omitted here.

[0221] - First communication device 600 and second communication device 700

[0222] For example, the first communication device 600 and the second communication device 700 are each one of a plurality of devices constituting a base station. System 2 (base station) may also include other devices (not shown) besides the first communication device 600 and the second communication device 700 (and a plurality of antennas 800).

[0223] The second communication device 700 is physically separate from the first communication device 600. For example, the second communication device 700 is connected to multiple antennas 800. The first communication device 600 is connected to the second communication device 700. For example, the first communication device 600 and the second communication device 700 are connected to each other via a communication line 23. The first communication device 600 receives information from the second communication device 700 via the communication line 23 and transmits information to the second communication device 700 via the communication line 23. For example, the communication line 23 is an optical fiber line (fiber optic cable). Furthermore, for example, the first communication device 600 is located indoors, and the second communication device 700 is located outdoors.

[0224] In the case where the base station (system 2) includes a first unit and a second unit (refer to the first example embodiment), the first communication device 600 may be the first unit (e.g., a digital unit (DU) or a BBU), and the second communication device 700 may be the second unit (e.g., a remote / radio unit (RU), an RRH, or an RRU). Optionally, the first communication device 600 and the second communication device 700 may be devices included in the second unit (e.g., a distributed unit (DU)).

[0225] --Multiple antennas 800

[0226] For example, multiple antennas 800 are each antenna elements included in a multi-element antenna. For example, a multi-element antenna is an antenna used in massive MIMO.

[0227] The structure of System 2 has been described above. As an example, the first communication device 600 may be the digital device 100 of the first example embodiment. The second communication device 700 may be the wireless device 200 of the first example embodiment. The plurality of antennas 800 may be the plurality of antennas 300 of the first example embodiment. Of course, the second example embodiment is not limited to this example. As an example, the first communication device 600 may be a device (component or module) included in the digital device 100 of the first example embodiment, and the second communication device 700 may be a device (component or module) included in the wireless device 200 of the first example embodiment. As another example, the first communication device 600 may be a third device different from a digital device, while the second communication device 700 is a wireless device.

[0228] <4.2. Structure of the First Communication Device>

[0229] Next, refer to Figure 16 This is an example illustrating the structure of the first communication device 600 according to the second example embodiment. Figure 16 This is a block diagram illustrating an example of the schematic structure of a first communication device 600 according to a second exemplary embodiment. (See reference...) Figure 16The first communication device 600 includes a receiving processing unit 610 and a transmitting processing unit 620.

[0230] The specific operations of the receiving processing unit 610 and the transmitting processing unit 620 will be explained later.

[0231] The receiving processing unit 610 and the transmitting processing unit 620 can be implemented using one or more processors (such as BB processors and / or other types of processors) and memory.

[0232] The first communication device 600 may include a memory storing a program (instructions) and one or more processors capable of executing the program (instructions). The one or more processors may execute the program to perform operations of the receiving processing unit 610 and the transmitting processing unit 620. The program may be a program used to cause the processor to perform operations of the receiving processing unit 610 and the transmitting processing unit 620.

[0233] Note that, of course, the first communication device 600 may also include constituent elements other than the receiving processing unit 610 and the transmitting processing unit 620. For example, the first communication device 600 may also include constituent elements included in the digital device 100 of the first example embodiment (e.g., interface 110, storage unit 120, radio communication processing unit 131 and / or generation unit 135).

[0234] <4.3. Structure of the Second Communication Equipment>

[0235] Next, refer to Figure 17 This is an example illustrating the structure of the second communication device 700 according to the second example embodiment. Figure 17 This is a block diagram illustrating an example of the schematic structure of a second communication device 700 according to a second exemplary embodiment. (See reference...) Figure 17 The second communication device 700 includes a radio communication processing unit 710, a transmission processing unit 720, and a reception processing unit 730.

[0236] The specific operation of the radio communication processing unit 710, the transmitting processing unit 720, and the receiving processing unit 730 will be described later.

[0237] The radio communication processing unit 710, the transmitting processing unit 720, and the receiving processing unit 730 can be implemented using one or more processors (such as BB processors and / or other types of processors) and memory.

[0238] The second communication device 700 may include a memory storing a program (instructions) and one or more processors capable of executing the program (instructions). The one or more processors may execute the program to perform operations of the radio communication processing unit 710, the transmitting processing unit 720, and the receiving processing unit 730. The program may be a program used to cause the processor to perform operations of the radio communication processing unit 710, the transmitting processing unit 720, and the receiving processing unit 730.

[0239] Note that, of course, the second communication device 700 may also include constituent elements other than the radio communication processing unit 710, the transmitting processing unit 720, and the receiving processing unit 730. For example, the second communication device 700 may also include constituent elements included in the radio device 200 of the first example embodiment (e.g., the first interface 210, the second interface 220, and / or the storage unit 230).

[0240] <4.4. Technical Features>

[0241] Next, the technical features of the second example embodiment will be described.

[0242] (1) Radio communication processing

[0243] The second communication device 700 (radio communication processing unit 710) receives signals via multiple antennas 800. Furthermore, particularly in the second example embodiment, the second communication device 700 (radio communication processing unit 710) multiplies the signals received via the multiple antennas 800 by the receiving antenna weights.

[0244] For example, the description of such radio communication processing (reception processing) is the same as that of the radio communication processing (reception processing) in the first example embodiment. Furthermore, the description of the transmission processing can also be the same as that of the transmission processing in the first example embodiment. In this case, the second communication device 700 (radio communication processing unit 710) can operate in the same manner as the radio device 200 (radio communication processing unit 241) of the first example embodiment. The first communication device 600 can operate in the same manner as the digital device 100 (radio communication processing unit 131) of the first example embodiment. Therefore, repeated descriptions are omitted here.

[0245] Of course, it should be noted that the second example embodiment is not limited to the example described above. As an example, it is not possible for other devices (digital devices) of the first communication device 600 to perform radio communication processing.

[0246] (2) Receiving antenna weight

[0247] In a particularly exemplary embodiment, the second communication device 700 (transmitting processing unit 720) transmits channel-related information concerning the channel of signals received via multiple antennas 800 to the first communication device 600. The first communication device 600 (receiving processing unit 610) receives the channel-related information from the second communication device 700.

[0248] Based on the channel-related information, weight information related to the receiving antenna weight is generated.

[0249] Furthermore, the first communication device 600 (transmission processing unit 620) sends the weight information to the second communication device 700. The second communication device 700 (receive processing unit 730) receives the weight information from the first communication device 600.

[0250] Then, the second communication device 700 (radio communication processing unit 710) multiplies the signal received by the multiple antennas 800 by the receiving antenna weight.

[0251] For example, the description of such receiving antenna weights is the same as that in the first example embodiment. In this case, the second communication device 700 (radio communication processing unit 710, transmitting processing unit 720, and receiving processing unit 730) can operate in the same manner as the radio device 200 (radio communication processing unit 241, transmitting processing unit 243, and receiving processing unit 245) in the first example embodiment. The first communication device 600 (receiving processing unit 610 and transmitting processing unit 620) can operate in the same manner as the digital device 100 (receiving processing unit 133 and transmitting processing unit 137) in the first example embodiment. Therefore, repeated descriptions are omitted here.

[0252] Of course, it should be noted that the second example embodiment is not limited to the example described above. As an example, it is not possible for other devices of the first communication device 600 to generate weight information based on channel-related information.

[0253] (3) Processing flow

[0254] As an example, the processing in the second example embodiment is the same as that in the first example embodiment. Therefore, a repeated description of this processing is omitted here. Of course, it should be noted that the second example embodiment is not limited to this example.

[0255] The second example embodiment has been described above. According to the second example embodiment, both the circuit size of the second communication device 700 and the bandwidth of the interface between the second communication device 700 and other communication devices (e.g., the first communication device 600) can be small. Note that the first variation of the first example embodiment can also be applied to the second example embodiment.

[0256] The foregoing has provided a description of exemplary embodiments of the present invention. However, the present invention is not limited to these exemplary embodiments. Those skilled in the art should understand that these exemplary embodiments are merely examples, and various changes can be made without departing from the scope and spirit of the present invention.

[0257] For example, the steps in the process described in this specification do not necessarily have to be performed in chronological order as shown in the corresponding sequence diagram. For example, the steps of the process may be performed in a different order than that shown in the sequence diagram, or in parallel. In addition, some steps in the process may be deleted, or more steps may be added to the process.

[0258] Methods for operating or processing a communication device (digital device, radio device, first communication device, or second communication device) as described in this specification may be provided, and programs for causing a processor to perform such operations or processing may be provided. Furthermore, non-transitory computer-readable recording media (NCMs) containing these programs may be provided. Obviously, these methods, programs, and NCMs are also included in this invention.

[0259] All or part of the exemplary embodiments disclosed above may be described in, but are not limited to, the following supplementary description.

[0260] (Supplementary Note 1)

[0261] A first communication device includes: a receiving processing unit configured to receive channel-related information relating to a channel of a signal received via a plurality of antennas from a second communication device for receiving signals via a plurality of antennas; and a transmitting processing unit configured to transmit weight information generated based on the channel-related information to the second communication device, the weight information relating to a receiving antenna weight multiplied by the signal received by the second communication device via the plurality of antennas.

[0262] (Supplementary Note 2)

[0263] According to Supplementary Explanation 1, the first communication device, wherein the weight information is information indicating the weight of the receiving antenna.

[0264] (Supplementary Note 3)

[0265] According to Supplementary Explanation 2, the first communication device includes information indicating the various weights included in the weights of the receiving antenna.

[0266] (Supplementary Note 4)

[0267] According to Supplementary Explanation 2, the first communication device wherein the receiving antenna weight is a receiving antenna weight set included in a predetermined plurality of receiving antenna weight sets, and the weight information is an index indicating the receiving antenna weight set.

[0268] (Supplementary Note 5)

[0269] According to any one of Supplementary Descriptions 1 to 4, in the first communication device, the transmission processing unit is configured to transmit the weight information and information related to the use of the receiving antenna weight to the second communication device.

[0270] (Supplementary Note 6)

[0271] According to the first communication device described in Supplementary Note 5, the information related to the use of the receiving antenna weights includes frequency information related to the frequency at which the receiving antenna weights are used.

[0272] (Supplementary Note 7)

[0273] According to Supplementary Note 6, the first communication device wherein the frequency information indicates a frequency block among a plurality of frequency blocks that uses the receiving antenna weight.

[0274] (Supplementary Note 8)

[0275] According to Supplementary Note 6 or 7, the first communication device wherein the frequency information indicates the frequency resolution of the receiving antenna weights.

[0276] (Supplementary Note 9)

[0277] According to any one of Supplementary Notes 6 to 8, the first communication device, wherein the channel is a channel between the terminal device and the plurality of antennas, the receiving antenna weight is a weight multiplied by the signal received by the second communication device from the terminal device via the plurality of antennas, and the frequency information is information related to the frequency allocated to the terminal device.

[0278] (Supplementary Note 10)

[0279] According to the first communication device described in Supplementary Explanation 5, the information related to the use of the receiving antenna weights includes time information related to the time when the receiving antenna weights are used.

[0280] (Supplementary Note 11)

[0281] According to Supplementary Note 10, the first communication device wherein the channel is a channel between the terminal device and the plurality of antennas, the receiving antenna weight is a weight multiplied by the signal received by the second communication device from the terminal device via the plurality of antennas, and the time information is information related to the time allocated to the terminal device.

[0282] (Supplementary Note 12)

[0283] According to any one of Supplementary Descriptions 1 to 11, the first communication device wherein the channel-related information is a reference signal received via the plurality of antennas.

[0284] (Supplementary Note 13)

[0285] According to any one of Supplementary Explanations 1 to 12, the channel-related information is a channel estimate calculated by the second communication device based on a reference signal received via the plurality of antennas through channel estimation.

[0286] (Supplementary Note 14)

[0287] According to Supplementary Description 12 or 13, the first communication device wherein the reference signal is a reference signal transmitted during a specific time period in a time frame.

[0288] (Supplementary Note 15)

[0289] According to Supplementary Note 14, the first communication device is wherein the time frame is a radio frame and the specific time period is a specific symbol.

[0290] (Supplementary Note 16)

[0291] According to any one of Supplementary Notes 12 to 15, the first communication device wherein the reference signal is a detection reference signal, i.e., SRS, or a demodulation reference signal, i.e., DMRS.

[0292] (Supplementary Note 17)

[0293] The first communication device according to any one of Supplementary Descriptions 1 to 16 further includes a generation unit configured to generate the weight information based on the channel-related information.

[0294] (Supplementary Note 18)

[0295] The first communication device according to any one of Supplementary Descriptions 1 to 17 further includes a radio communication processing unit configured to demodulate and decode signals of one or more layers generated by the second communication device by multiplying signals received via the plurality of antennas with the weights of the receiving antennas.

[0296] (Supplementary Note 19)

[0297] According to any one of Supplementary Descriptions 1 to 18, in the first communication device, the transmission processing unit is configured to send to the second communication device other weight information related to the transmission antenna weights used by the second communication device to generate a signal to be transmitted via the plurality of antennas, the other weight information being generated based on the channel-related information.

[0298] (Supplementary Note 20)

[0299] According to any one of Supplementary Notes 1 to 18, the receiving antenna weight is the same antenna weight used by the second communication device to generate a signal to be transmitted via the plurality of antennas.

[0300] (Supplementary Note 21)

[0301] According to the first communication device described in Supplementary Description 19 or 20, the second communication device is a device for performing time-division duplex (TDD) communication.

[0302] (Supplementary Note 22)

[0303] According to any one of Supplementary Notes 1 to 21, the first communication device wherein the signal is an uplink signal.

[0304] (Supplementary Note 23)

[0305] According to any one of Supplementary Explanations 1 to 22, the first communication device and the second communication device are each one of a plurality of devices constituting a base station.

[0306] (Supplementary Note 24)

[0307] According to any one of Supplementary Explanations 1 to 23, the first communication device, wherein the channel is a channel between the terminal device and the plurality of antennas, and the receiving antenna weight is a weight multiplied by the signal received by the second communication device from the terminal device via the plurality of antennas.

[0308] (Supplementary Note 25)

[0309] According to any one of Supplementary Descriptions 1 to 24, the first communication device wherein each of the plurality of antennas is an antenna element included in a multi-element antenna.

[0310] (Supplementary Note 26)

[0311] According to the first communication device described in Supplementary Note 25, the multi-element antenna is an antenna used for massive MIMO (Multi-Input Multiple-Output).

[0312] (Supplementary Note 27)

[0313] According to any one of Supplementary Descriptions 1 to 26, in the first communication device, the transmitting processing unit is configured to receive the channel-related information from the second communication device via a communication line, and the receiving processing unit is configured to transmit the weight information to the second communication device via the communication line.

[0314] (Supplementary Note 28)

[0315] According to Supplementary Note 27, the first communication device is wherein the communication line is an optical fiber line.

[0316] (Supplementary Note 29)

[0317] According to any one of Supplementary Explanations 1 to 28, the first communication device is a device physically separate from the first communication device.

[0318] (Supplementary Note 30)

[0319] According to any one of Supplementary Descriptions 1 to 29, the first communication device is a device connected to the plurality of antennas, and the first communication device is a device connected to the second communication device.

[0320] (Supplementary Note 31)

[0321] According to any one of Supplementary Explanations 1 to 30, the first communication device is an indoor device, and the second communication device is an outdoor device.

[0322] (Supplementary Note 32)

[0323] A second communication device includes: a radio communication processing unit configured to receive signals via a plurality of antennas; a transmission processing unit configured to transmit channel-related information relating to a channel of the signals received via the plurality of antennas to a first communication device; and a reception processing unit configured to receive weight information relating to reception antenna weights from the first communication device, the weight information being generated based on the channel-related information, wherein the radio communication processing unit is configured to multiply the signals received via the plurality of antennas by the reception antenna weights.

[0324] (Supplementary Explanation 33)

[0325] A method includes: receiving channel-related information from a communication device for receiving signals via a plurality of antennas, relating to a channel of the signals received via the plurality of antennas; and sending weight information relating to receiving antenna weights to the communication device, wherein the communication device multiplies the signals received via the plurality of antennas by the receiving antenna weights, the weight information being generated based on the channel-related information.

[0326] (Supplementary Note 34)

[0327] A method includes: receiving signals via a plurality of antennas; sending channel-related information to a communication device relating to a channel of the signals received via the plurality of antennas; receiving from the communication device weight information relating to receiving antenna weights, the weight information being generated based on the channel-related information; and multiplying the signals received via the plurality of antennas by the receiving antenna weights.

[0328] (Supplementary Note 35)

[0329] A program for causing a processor to perform: receiving channel-related information from a communication device for receiving signals via a plurality of antennas, relating to a channel of signals received via the plurality of antennas; and sending weight information relating to receiving antenna weights to the communication device, wherein the communication device multiplies the signals received via the plurality of antennas by the receiving antenna weights, the weight information being generated based on the channel-related information.

[0330] (Supplementary Explanation 36)

[0331] A program for causing a processor to perform: receiving signals via a plurality of antennas; sending channel-related information to a communication device relating to the channels of the signals received via the plurality of antennas; receiving from the communication device weight information relating to receiving antenna weights, the weight information being generated based on the channel-related information; and multiplying the signals received via the plurality of antennas by the receiving antenna weights.

[0332] (Supplementary Note 37)

[0333] A non-transitory computer-readable recording medium containing a program for causing a processor to execute: receiving channel-related information from a communication device for receiving signals via a plurality of antennas, relating to a channel of signals received via the plurality of antennas; and sending weight information relating to receiving antenna weights to the communication device, wherein the communication device multiplies the signals received via the plurality of antennas by the receiving antenna weights, the weight information being generated based on the channel-related information.

[0334] (Supplementary Note 38)

[0335] A non-transitory computer-readable recording medium containing a program for causing a processor to perform: receiving signals via a plurality of antennas; sending to a communication device channel-related information relating to a channel of the signals received via the plurality of antennas; receiving from the communication device weight information relating to receiving antenna weights, the weight information being generated based on the channel-related information; and multiplying the signals received via the plurality of antennas by the receiving antenna weights.

[0336] (Supplementary Note 39)

[0337] A system includes: a first communication device; and a second communication device, wherein the second communication device is configured to: receive signals via a plurality of antennas; and send channel-related information relating to a channel of the signals received via the plurality of antennas to the first communication device, the first communication device being configured to: receive the channel-related information from the second communication device; and send weight information relating to receiving antenna weights to the second communication device, the weight information being generated based on the channel-related information, and the second communication device being configured to: receive the weight information from the first communication device; and multiply the signals received via the plurality of antennas by the receiving antenna weights.

[0338] (Supplementary Note 40)

[0339] A method includes: receiving signals via a plurality of antennas in a second communication device; sending channel-related information relating to a channel of the signals received via the plurality of antennas to a first communication device, wherein the channel-related information is received from the second communication device in the first communication device; sending weight information relating to receiving antenna weights to the second communication device, the weight information being generated based on the channel-related information, wherein the weight information is received from the first communication device in the second communication device; and multiplying the signals received via the plurality of antennas by the receiving antenna weights.

[0340] This application is based on and claims priority to Japanese Patent Application 2017-055726, filed on March 22, 2017, the entire contents of which are incorporated herein by reference.

[0341] Industrial availability

[0342] In mobile communication systems, both the circuit size of the device used to receive signals via an antenna and the bandwidth of the interface between devices can be small.

[0343] List of reference numerals

[0344] 1,2 system

[0345] 10 base stations

[0346] 21,23 Communication lines

[0347] 40 terminal devices

[0348] 100 Digital Devices

[0349] 131 Radio Communication Processing Unit

[0350] 133,610 Receiver Processing Unit

[0351] 135 generation units

[0352] 137,620 Transmission Processing Unit

[0353] 200 wireless equipment

[0354] 241,710 Radio Communication Processing Unit

[0355] 243,720 Transmission Processing Unit

[0356] 245,730 Receiver Processing Unit

[0357] 300, 800 antennas

[0358] 411 Channel Estimation Unit

[0359] 413 Antenna Weight Generation Unit

[0360] 600 First Communication Equipment

[0361] 700 Second Communication Equipment

[0362] 1001 time frames

[0363] 1003 Specific time period

[0364] 1011 Reference Signal

Claims

1. A method performed by a baseband unit, the method comprising: Maintain the first physical layer; Receive reference signals from a radio unit configured to maintain a second physical layer and receive signals via a plurality of antennas, the second physical layer being located at a layer in the communication protocol lower than the first physical layer; Channel estimation is performed based on the reference signal; as well as The radio unit sends weight information related to the receiving antenna weights, which are multiplied by the signals received via the plurality of antennas. The baseband unit and the radio unit are each one of several devices constituting a base station. The baseband unit and the radio unit are physically separate, and the baseband unit and the radio unit are linked by an interface requiring a frequency band.

2. The method according to claim 1, wherein, The weight information is information indicating the weight of the receiving antenna.

3. The method according to claim 2, wherein, The weight information includes information indicating the individual weights included in the weight of the receiving antenna.

4. The method according to claim 2, wherein, The receiving antenna weight is a set of receiving antenna weights included in a predetermined set of multiple receiving antenna weight sets, and The weight information is an index indicating the weight set of the receiving antenna.

5. The method according to claim 1, wherein, The weight information is generated based on the channel estimate calculated through the channel estimation.

6. The method according to claim 1, further comprising: The weight information and information related to the use of the receiving antenna weight are sent to the radio unit.

7. The method according to claim 6, wherein, The information relating to the use of the receiving antenna weights includes frequency information relating to the frequency at which the receiving antenna weights are used.

8. The method according to claim 6, wherein, The information relating to the use of the receiving antenna weights includes time information relating to the time the receiving antenna weights are used.

9. The method according to claim 1, wherein, The reference signal is a reference signal transmitted during a specific time period in a time frame.

10. The method according to claim 9, wherein, The time frame is a radio frame, and The specific time period is a specific symbol.

11. The method according to claim 1, wherein, The reference signal is either a detection reference signal (SRS) or a demodulation reference signal (DMRS).

12. The method according to claim 1, further comprising: The weight information is generated based on the reference signal.

13. The method according to claim 1, further comprising: The radio unit demodulates and decodes signals generated by multiplying the signals received via the plurality of antennas by the weights of the receiving antennas, resulting in one or more layers of signals.

14. The method according to claim 1, further comprising: The radio unit is sent additional weight information relating to the transmit antenna weights used by the radio unit to generate signals to be transmitted via the plurality of antennas, the additional weight information being generated based on the reference signal.

15. The method according to claim 1, wherein, The receiving antenna weights are the same antenna weights used by the radio unit to generate signals that will be transmitted via the multiple antennas.

16. The method of claim 14, wherein, The radio unit is a device used for time-division duplex (TDD) communication.

17. The method according to claim 1, wherein, The receiving antenna weight is the weight by which the radio unit multiplies the signal from the terminal device, which is received via the plurality of antennas.

18. The method according to claim 1, further comprising: Send other weight information related to the transmit antenna weight to the radio unit, and The other weight information related to the transmit antenna weight is information in the same format as the weight information related to the receive antenna weight.

19. A method performed by a radio unit, comprising: Maintain the second physical layer located in the communication protocol, which is lower than the first physical layer; Signals are received via multiple antennas; A reference signal is sent to the baseband unit for channel estimation, wherein the baseband unit is configured to maintain the first physical layer; Receive weight information related to the receiving antenna weight from the baseband unit; as well as The signal received via the plurality of antennas is multiplied by the weight of the receiving antenna. The baseband unit and the radio unit are each one of several devices constituting a base station. The baseband unit and the radio unit are physically separate, and the baseband unit and the radio unit are linked by an interface requiring a frequency band.

20. A baseband unit, comprising: A memory that stores instructions; as well as One or more processors are configured to execute the instructions to: Maintain the first physical layer; Receive reference signals from a radio unit configured to maintain a second physical layer and receive signals via a plurality of antennas, the second physical layer being located at a layer in the communication protocol lower than the first physical layer; Channel estimation is performed based on the reference signal; as well as Weighting information related to the receiving antenna weights is sent to the radio unit. These receiving antenna weights are multiplied by the radio unit along with the signals received via the plurality of antennas. The baseband unit and the radio unit are each one of several devices constituting a base station. The baseband unit and the radio unit are physically separate, and the baseband unit and the radio unit are linked by an interface requiring a frequency band.

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