First communication device, second communication device, method, and system

Abstract

To enable suppression of both the circuit scale of a device that receives a signal via an antenna and the bandwidth of an interface between devices. [Solution] A first communication device of the present invention comprises a receiving processing unit that receives channel-related information regarding the channels of signals received via multiple antennas from a second communication device that receives signals via the multiple antennas, and a transmitting processing unit that transmits weight information regarding receiving antenna weights that the second communication device multiplies by the signals received via the multiple antennas, the weight information being generated based on the channel-related information, to the second communication device.

Description

[Technical field]

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

[0002] As mobile communications become more sophisticated, data transmission speeds are increasing faster than the available frequency bands. Therefore, beamforming using multi-element antennas, which can increase the data transmission speed per frequency, is considered to be a promising method. In beamforming, a beam for reception (and transmission) is formed based on a channel estimate obtained from the received signal of each antenna element included in the multi-element antenna.

[0003] For example, Patent Document 1 describes that a base station determines a transmit beamforming weight and performs transmit beamforming, and a terminal device determines a receive beamforming weight and performs receive beamforming. For example, Patent Document 2 describes that a terminal device determines a transmit antenna weight and a receive antenna weight based on a reference signal from a base station, and reports information on these weights to the base station. Patent Document 3 describes an example of the structure of a base station separated into an RRU (Remote Radio Unit) and a BBU (Base Band Unit). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2016 / 152916 [Patent Document 2] International Publication No. 2016 / 207929 [Patent Document 3] US Patent Application Publication No. 2014 / 0226736 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, as described in Patent Document 3, a base station may be separated into a device (e.g., an RRU) that receives a signal via an antenna and another device (e.g., a BBU). In such a case, which device performs processes such as channel estimation, antenna weight generation, and antenna weight multiplication may affect the circuit scale of the device (e.g., an RRU) and the bandwidth of the interface between the devices. However, Patent Document 3 does not consider which device performs these processes. Therefore, the technology described in Patent Document 3 cannot suppress both the circuit scale of the device and the bandwidth of the interface between the devices.

[0006] An object of the present invention is to provide a first communication device and a second communication device that enable suppression of both the circuit scale of a device that receives a signal via an antenna and the bandwidth of an interface between the devices. [Means for solving the problem]

[0007] A first communication device according to one aspect of the present invention includes a receiving processing unit that receives channel-related information related to channels of signals received via multiple antennas from a second communication device that receives signals via the multiple antennas, and a transmitting processing unit that transmits weight information related to receiving antenna weights by which the second communication device multiplies the signals received via the multiple antennas, the weight information being generated based on the channel-related information, to the second communication device.

[0008] A second communication device according to one embodiment of the present invention comprises a wireless communication processing unit that receives signals via multiple antennas, a transmission processing unit that transmits channel-related information regarding channels of the signals received via the multiple antennas to a first communication device, and a reception processing unit that receives weight information regarding receiving antenna weights from the first communication device, the weight information being generated based on the channel-related information, and the wireless communication processing unit multiplies the signals received via the multiple antennas by the receiving antenna weights.

[0009] A first method according to one embodiment of the present invention includes receiving, from a communication device receiving signals via multiple antennas, channel-related information regarding channels of the signals received via the multiple antennas, and transmitting, to the communication device, weight information regarding receiving antenna weights by which the communication device multiplies the signals received via the multiple antennas, the weight information being generated based on the channel-related information.

[0010] A second method according to one embodiment of the present invention includes receiving signals via a plurality of antennas, transmitting channel-related information related to channels of the signals received via the plurality of antennas to a communication device, receiving weight information related to receiving antenna weights from the communication device, 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.

[0011] A first program according to one embodiment of the present invention is a program that causes a processor to execute the following steps: receive channel-related information regarding channels of signals received via multiple antennas from a communication device that receives signals via the multiple antennas; and transmit weight information regarding receiving antenna weights that the communication device multiplies by the signals received via the multiple antennas, the weight information being generated based on the channel-related information, to the communication device.

[0012] A second program according to one embodiment of the present invention is a program that causes a processor to execute the following operations: receiving signals via multiple antennas; transmitting channel-related information regarding channels of the signals received via the multiple antennas to a communication device; receiving weight information regarding receiving antenna weights from the communication device, the weight information being generated based on the channel-related information; and multiplying the signals received via the multiple antennas by the receiving antenna weights.

[0013] A first recording medium according to one embodiment of the present invention is a non-transitory recording medium readable by a computer having recorded thereon a program that causes a processor to execute the following operations: receiving channel-related information regarding channels of signals received via multiple antennas from a communication device that receives signals via the multiple antennas; and transmitting weight information regarding receiving antenna weights that the communication device multiplies by the signals received via the multiple antennas, the weight information being generated based on the channel-related information, to the communication device.

[0014] A second recording medium according to one embodiment of the present invention is a non-transitory recording medium readable by a computer having recorded thereon a program that causes a processor to execute the following operations: receiving signals via multiple antennas; transmitting channel-related information regarding channels of the signals received via the multiple antennas to a communication device; receiving weight information regarding receiving antenna weights from the communication device, the weight information being generated based on the channel-related information; and multiplying the signals received via the multiple antennas by the receiving antenna weights.

[0015] A system according to one embodiment of the present invention includes a first communication device and a second communication device, wherein the second communication device receives signals via multiple antennas and transmits channel-related information regarding channels of the signals received via the multiple antennas to the first communication device, the first communication device receives the channel-related information from the second communication device and transmits weight information regarding receiving antenna weights, the weight information being generated based on the channel-related information, to the second communication device, and the second communication device receives the weight information from the first communication device and multiplies the signals received via the multiple antennas by the receiving antenna weights.

[0016] A third method according to one embodiment of the present invention includes receiving signals via multiple antennas in a second communication device, transmitting channel-related information regarding channels of the signals received via the multiple antennas to a first communication device, receiving the channel-related information from the second communication device in the first communication device, transmitting weight information regarding receiving antenna weights to the second communication device, the weight information being generated based on the channel-related information, receiving the weight information from the first communication device in the second communication device, and multiplying the signals received via the multiple antennas by the receiving antenna weights. Effect of the Invention

[0017] According to the present invention, it is possible to suppress both the circuit scale of a device that receives a signal via an antenna and the bandwidth of an interface between devices. Note that the present invention may provide other effects instead of or in addition to the above effect. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is an explanatory diagram for explaining an example of the configuration of a base station using a multi-element antenna. [Diagram 2] FIG. 11 is an explanatory diagram for explaining a first processing arrangement case of a base station. [Diagram 3] FIG. 11 is an explanatory diagram for explaining a second processing arrangement case of a base station. [Figure 4] FIG. 1 is an explanatory diagram illustrating an example of a schematic configuration of a system according to a first embodiment. [Diagram 5] FIG. 2 is an explanatory diagram illustrating an example of a schematic configuration of a base station according to the first embodiment. [Figure 6] 1 is a block diagram showing an example of a schematic configuration of a digital device according to a first embodiment. [Figure 7] 1 is a block diagram showing an example of a schematic configuration of a wireless device according to a first embodiment. [Figure 8] FIG. 2 is an explanatory diagram for explaining a schematic example of wireless communication processing according to the first embodiment; [Figure 9] FIG. 2 is an explanatory diagram for explaining a first example of channel estimation and weighting information generation according to the first embodiment. [Figure 10] FIG. 4 is an explanatory diagram for explaining an example of a reference signal according to the first embodiment. [Figure 11] FIG. 4 is an explanatory diagram for explaining an example of transmission of a reference signal according to the first embodiment. [Figure 12] FIG. 11 is an explanatory diagram for explaining a second example of channel estimation and weighting information generation according to the first embodiment. [Figure 13] 4 is a sequence diagram for explaining an example of a schematic flow of wireless communication processing according to the first embodiment. FIG. [Figure 14] 4 is a sequence diagram illustrating an example of a schematic flow of a process of transmitting and receiving channel associated information and weight information according to the first embodiment. FIG. [Figure 15] FIG. 11 is an explanatory diagram illustrating an example of a schematic configuration of a system according to a second embodiment. [Figure 16] FIG. 11 is a block diagram showing an example of a schematic configuration of a first communication device according to a second embodiment. [Figure 17] FIG. 11 is a block diagram showing an example of a schematic configuration of a second communication device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this specification and the drawings, elements that can be similarly described may be designated by the same reference numerals to avoid repetitive description.

[0020] The explanation will be given in the following order: 1. Related technologies 2. Overview of the embodiment 3. First embodiment 3.1. System Configuration 3.2. Digital Device Configuration 3.3. Wireless Device Configuration Technical Features 3.5. Variations 4. Second embodiment 4.1. System Configuration 4.2. Configuration of the First Communication Device 4.3. Configuration of the Second Communication Device 4.4. Technical Features

[0021] <<1. Related Technology>> First, the related art will be described with reference to Figures 1 to 3. Note that, naturally, the related art described here can also be included in the embodiments of the present invention.

[0022] -Example of a base station configuration using a multi-element antenna FIG. 1 is an explanatory diagram for explaining an example of the configuration of a base station 50 that uses a multi-element antenna.

[0023] --Reception processing Radio reception signals (N sequence radio reception signals) of N antenna elements 51 included in the multi-element antenna are converted by a transmitting / receiving unit 53 into N sequence reception baseband signals on the time axis, and further converted by an FFT (Fast Fourier Transform) unit 55 into N sequence reception signals on the frequency axis. Furthermore, the N sequence reception signals are multiplied by an M row and N column reception antenna weight matrix by an antenna weight multiplication unit 57. As a result, an M sequence reception signal (i.e., an M layer reception signal) is output. The M sequence reception signal is demodulated by a demodulation unit 59, and further decoded by a decoding unit 61.

[0024] Furthermore, the channel estimation unit 63 performs channel estimation based on a reference signal included in the above-mentioned N sequence received signal, which is the output of the FFT unit 55. As a result, an N sequence channel estimation value is generated and output. Furthermore, the antenna weight generation unit 65 generates a receiving antenna weight matrix with M rows and N columns based on the above-mentioned N sequence channel estimation value. Then, the receiving antenna weight matrix is ​​used by the antenna weight multiplication unit 57 as described above. Note that the antenna weight generation unit 65 may also generate a transmitting antenna weight matrix with N rows and L columns based on the above-mentioned N sequence channel estimation value.

[0025] --Transmission process The transmission signal is first coded by the coding unit 71 and then modulated by the modulation unit 73. As a result, the transmission signal becomes an L sequence transmission signal (L layer transmission signal). The L sequence transmission signal is multiplied by a transmission antenna weight matrix of N rows and L columns by the antenna weight multiplication unit 75 to become an N sequence transmission signal on the frequency axis. The N sequence transmission signal on the frequency axis is converted by an IFFT (Inverse Fast Fourier Transform) unit 77 into an N sequence baseband signal on the time axis, and further converted by the transmission / reception unit 53 into an N sequence radio transmission signal. Then, the N sequence radio transmission signal is transmitted from N antenna elements included in the multi-element antenna.

[0026] Processing arrangement in base station 1 is divided into, for example, a radio device including a transceiver unit 53 and a digital device including a demodulator unit 59, a decoder unit 61, an encoder unit 71, and a modulator unit 73. For example, the radio device is disposed in the immediate vicinity of the multi-element antenna, and the digital device is disposed in an indoor station building, and the radio device and the digital device are connected to each other by an optical fiber cable.

[0027] Here, there are two possible cases: a case in which the antenna weight multiplication units 57, 75 and the antenna weight generation unit 65 are arranged in a digital device (first processing arrangement case), and a case in which the antenna weight multiplication units 57, 75 and the antenna weight generation unit 65 are arranged in a wireless device (second processing arrangement case).

[0028] --First processing arrangement case 2 is an explanatory diagram for explaining a first processing arrangement case of the 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 digital device 90 instead of the wireless device 80.

[0029] In the first processing arrangement case, the circuit scale of the radio device 80 is small, and it is easier to reduce the size and weight of the radio device 80. However, in this case, an interface for N series of signals (i.e., N interfaces) is required for each of reception and transmission between the radio device 80 and the digital device 90. Therefore, when the number of antenna elements N is very large, a very large bandwidth is required between the radio device 80 and the digital device 90.

[0030] --Second processing arrangement case 3 is an explanatory diagram for explaining a second processing arrangement case of the 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 wireless device 80 instead of the digital device 90.

[0031] In the second processing arrangement case, only an interface for M-sequence signals for reception (i.e., M interfaces) and an interface for L-sequence signals for transmission (i.e., L interfaces) are required between the radio device 80 and the digital device 90. Therefore, even if the number of antenna elements N is very large, a very large bandwidth is not required between the radio device 80 and the digital device 90. However, since channel estimation and generation of antenna weights (especially the latter) are complex and special processes, the circuit scale of the radio device 80 becomes large, making it difficult to reduce the size and weight of the radio device 80. Furthermore, since channel estimation and generation of antenna weights are processes for each user (terminal device), it is necessary for the radio device 80 to perform the processes while being aware of the user (terminal device).

[0032] In view of the above, it is desirable to be able to reduce both the circuit size of a device (wireless device) that receives a signal via an antenna and the bandwidth of an interface between devices (an interface between a wireless device and a digital device).

[0033] <<2. Overview of the embodiment>> In an embodiment of the present invention (hereinafter, referred to as the present embodiment), a wireless device receives signals via multiple antennas (e.g., multiple antenna elements included in a multi-element antenna). Furthermore, particularly in the present embodiment, the wireless device multiplies the signals received via the multiple antennas by receiving antenna weights.

[0034] In particular, in this embodiment, the wireless device transmits channel-related information regarding channels of signals received via the multiple antennas to a digital device, and the digital device receives the channel-related information. Then, weight information regarding receiving antenna weights is generated based on the channel-related information. Furthermore, the digital device transmits the weight information to the wireless device, and the wireless device receives the weight information. Then, the wireless device multiplies the signals received via the multiple antennas by the receiving antenna weights.

[0035] This can reduce, for example, both the circuit scale of the wireless device and the bandwidth of the interface between the wireless device and the digital device.

[0036] The above-mentioned technical features are a specific example of the present embodiment, and the present embodiment is not limited to the above-mentioned technical features.

[0037] <<3. First embodiment>> Next, a first embodiment of the present invention will be described with reference to FIGS.

[0038] <3.1. System configuration> First, an example of the configuration of the system 1 according to the first embodiment will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is an explanatory diagram showing an example of a schematic configuration of the system 1 according to the first embodiment. With reference to Fig. 4, the system 1 includes a base station 10 and a terminal device 40.

[0039] For example, the system 1 is a system that complies with the standard of the Third Generation Partnership Project (3GPP). More specifically, the system 1 may be a system that complies with LTE / LTE-Advanced and / or SAE (System Architecture Evolution). Alternatively, the system 1 may be a system that complies with the standard of the fifth generation (5G). Of course, the system 1 is not limited to these examples.

[0040] (1)Base station 10 The base station 10 is a node of a radio access network (RAN), and performs wireless communication with terminal devices (for example, terminal device 40) located within its coverage area.

[0041] -Specific Example of Base Station 10 The base station 10 is a node that performs wireless communication with a terminal device, in other words, a node of a radio access network (RAN). For example, the base station 10 may be an evolved Node B (eNB), or may be a generation Node B (gNB) in 5G. The base station 10 may include a plurality of units (or a plurality of nodes). The plurality of units (or a plurality of nodes) may include a first unit (or a first node) that processes a higher protocol layer, and a second unit (or a second node) that processes a lower protocol layer. As an example, the first unit may be called a Center / Central Unit (CU), and the second unit may be called a Distributed Unit (DU) or an Access Unit (AU). As another example, the first unit may be called a Digital Unit (DU), and the second unit may be called a Radio Unit (RU) or a Remote Unit (RU). The DU (Digital Unit) may be a BBU (Base Band Unit), and the RU may be an RRH (Remote Radio Head) or an RRU (Remote Radio Unit). Naturally, the names of the first unit (or the first node) and the second unit (or the second node) are not limited to this example. Alternatively, the base station 10 may be a single unit (or a single node). In this case, the base station 10 may be one of the multiple units (e.g., the second unit), and may be connected to another unit (e.g., the first unit) of the multiple units.

[0042] -Configuration of base station 10 Fig. 5 is an explanatory diagram showing an example of a schematic configuration of the base station 10 according to the first embodiment. Referring to Fig. 5, the base station 10 includes a digital device 100, a wireless device 200, and a plurality of antennas 300. For example, the base station 10 includes N antennas 300.

[0043] --Digital device 100 and wireless device 200 Each of the digital device 100 and the wireless device 200 is one of a plurality of devices that constitute the base station 10. The base station 10 may further include other devices (not shown) in addition to the digital device 100 and the wireless device 200 (and the plurality of antennas 300).

[0044] The wireless device 200 is a device physically separated from the digital device 100. The wireless device 200 is connected to a plurality of antennas 300, and the digital device 100 is connected to the wireless device 200. The digital device 100 and the wireless device 200 are connected to each other by a communication line 21. The digital device 100 receives information from the wireless device 200 via the communication line 21, and transmits information to the wireless device 200 via the communication line 21. For example, the communication line 21 is an optical fiber line. Also, for example, the digital device 100 is installed indoors, and the wireless device 200 is installed outdoors.

[0045] When the base station 10 includes the first unit and the second unit as described above, the digital device 100 may be the first unit (e.g., a DU (Digital Unit) or a BBU), and the wireless device 200 may be the second unit (e.g., a RU (Remote / Radio Unit), an RRH, or an RRU). Alternatively, the digital device 100 and the wireless device 200 may be devices included in the second unit (e.g., a DU (Distributed Unit)).

[0046] It should be noted that the digital device 100 is called a digital device because it processes digital signals, but it can more generally be called a communication device. The wireless device 200 is called a wireless device because it processes radio signals as described below, but it can more generally be called a communication device. Naturally, the wireless device 200 can process not only radio signals but also digital signals. Here, in order to facilitate understanding of the first embodiment, the names digital device and wireless device are used instead of communication device.

[0047] --Multiple antennas 300 For example, each of the plurality of antennas 300 is an antenna element included in a multi-element antenna, for example, a massive multiple-input and multiple-output (MIMO) antenna.

[0048] (2) Terminal device 40 The terminal device 40 performs wireless communication with a base station. For example, when the terminal device 40 is located within the coverage area of ​​the base station 10, the terminal device 40 performs wireless communication with the base station 10. For example, the terminal device 40 may be called a user equipment (UE), a user terminal, or a mobile station.

[0049] Although only one terminal device 40 is illustrated in FIG. 4, it goes without saying that multiple terminal devices 40 may be present.

[0050] <3.2. Digital device configuration> Next, an example of the configuration of the digital device 100 according to the first embodiment will be described with reference to Fig. 6. Fig. 6 is a block diagram showing an example of a schematic configuration of the digital device 100 according to the first embodiment. Referring to Fig. 6, the digital device 100 includes an interface 110, a storage unit 120, and a processing unit 130.

[0051] (1) Interface 110 The interface 110 is an interface for communication with the wireless device 200. In other words, the interface 110 is an interface for a communication line 21 (e.g., an optical fiber line) that connects the digital device 100 and the wireless device 200. The interface 110 receives signals from the wireless device 200 and transmits signals to the wireless device 200.

[0052] (2) Storage section 120 The storage unit 120 temporarily or permanently stores programs (instructions) and parameters, as well as various data, for the operation of the digital device 100. The programs include one or more instructions for the operation of the digital device 100.

[0053] (3) Processing section 130 The processing unit 130 provides various functions of the digital device 100. The processing unit 130 includes a wireless communication processing unit 131, a reception processing unit 133, a generation unit 135, and a transmission processing unit 137. The processing unit 130 may further include other components in addition to these components. That is, the processing unit 130 may also perform operations other than those of these components. Specific operations of the wireless communication processing unit 131, the reception processing unit 133, the generation unit 135, and the transmission processing unit 137 will be described in detail later.

[0054] For example, the processing unit 130 communicates with the wireless device 200 via the interface 110 .

[0055] (4) Implementation example The interface 110 may be implemented by a converter (e.g., an O / E (Optical / Electrical) converter and / or an E / O (Electrical / Optical) converter), etc. The storage unit 120 may be implemented by a memory (e.g., a non-volatile memory and / or a volatile memory) and / or a hard disk, etc. The processing unit 130 may be implemented by one or more processors, such as a baseband (BB) processor and / or other types of processors. The wireless communication processing unit 131, the reception processing unit 133, the generation unit 135, and the transmission processing unit 137 may be implemented by the same processor, or may be implemented separately by different processors. The memory (storage unit 120) may be included in the one or more processors, or may be outside the one or more processors.

[0056] The digital device 100 may include a memory that stores 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 the operation of the processing unit 130 (the operation of the wireless communication processing unit 131, the reception processing unit 133, the generation unit 135, and / or the transmission processing unit 137). The program may be a program for causing the processor to execute the operation of the processing unit 130 (the operation of the wireless communication processing unit 131, the reception processing unit 133, the generation unit 135, and / or the transmission processing unit 137).

[0057] <3.3. Wireless device configuration> Next, an example of the configuration of the wireless device 200 according to the first embodiment will be described with reference to Fig. 7. Fig. 7 is a block diagram showing an example of a schematic configuration of the wireless device 200 according to the first embodiment. Referring to Fig. 7, the wireless device 200 includes a first interface 210, a second interface 220, a storage unit 230, and a processing unit 240.

[0058] (1) First interface 210 The first interface 210 is an interface for wireless communication via the multiple antennas 300. The first interface 210 receives wireless signals from the multiple antennas 300 and transmits wireless signals to the multiple antennas 300.

[0059] (2) Second interface 220 The second interface 220 is an interface for communication with the digital device 100. In other words, the second interface 220 is an interface for a communication line 21 (e.g., an optical fiber line) that connects the digital device 100 and the wireless device 200. The second interface 220 receives signals from the digital device 100 and transmits signals to the digital device 100.

[0060] (3) Storage section 230 The memory unit 230 temporarily or permanently stores programs (instructions) and parameters, as well as various data, for the operation of the wireless device 200. The programs include one or more instructions for the operation of the wireless device 200.

[0061] (4) Processing section 240 The processing unit 240 provides various functions of the wireless device 200. The processing unit 240 includes a wireless communication processing unit 241, a transmission processing unit 243, and a reception processing unit 245. The processing unit 240 may further include other components in addition to these components. That is, the processing unit 240 may perform operations other than those of these components. The specific operations of the wireless communication processing unit 241, the transmission processing unit 243, and the reception processing unit 245 will be described in detail later.

[0062] For example, the processing unit 240 communicates with the digital device 100 via the second interface 220. Also, the processing unit 240 (wireless communication processing unit 241) transmits and receives wireless signals via the first interface 210 (and thus via the multiple antennas 300).

[0063] (5) Implementation example The first interface 210 may be implemented by a radio frequency (RF) circuit and an A / D converter, etc. The second interface 220 may be implemented by a converter (e.g., an O / E converter and / or an E / O converter), etc. The storage unit 230 may be implemented by a memory (e.g., a non-volatile memory and / or a volatile memory) and / or a hard disk, etc. The processing unit 240 may be implemented by one or more processors, such as a BB processor and / or other types of processors. The wireless communication processing unit 241, the transmission processing unit 243, and the reception processing unit 245 may be implemented by the same processor, or may be implemented separately by different processors. The memory (storage unit 230) may be included in the one or more processors, or may be outside the one or more processors.

[0064] Wireless device 200 may include a memory that stores 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 the operation of processing unit 240 (the operation of wireless communication processing unit 241, transmission processing unit 243, and / or reception processing unit 245). The program may be a program for causing a processor to execute the operation of processing unit 240 (the operation of wireless communication processing unit 241, transmission processing unit 243, and / or reception processing unit 245).

[0065] <3.4. Technical features> Next, technical features of the first embodiment will be described with reference to FIGS.

[0066] (1) Wireless communication processing - Inbound processing The wireless device 200 (the first interface 210 and the wireless communication processing unit 241) receives signals via a plurality of antennas 300. Furthermore, particularly in the first embodiment, the wireless device 200 (the wireless communication processing unit 241) multiplies the signals received via the plurality of antennas 300 by receiving antenna weights. The receiving antenna weights can also be called, for example, (receiving) beamforming weights (i.e., weights for performing beamforming on the receiving side).

[0067] For example, the digital device 100 (wireless communication processing unit 131) demodulates and decodes one or more layer signals generated by the wireless device 200 multiplying the signals received via the multiple antennas 300 by the receiving antenna weights.

[0068] An example of reception processing of the digital device 100 and the wireless device 200 will be described with reference to Fig. 8. Fig. 8 is an explanatory diagram for explaining a schematic example of wireless communication processing in the first embodiment.

[0069] Radio device 200 (transmitter / receiver 401) converts radio reception signals (N sequence radio reception signals) of the plurality of antennas 300 (N antennas 300) into N sequence reception baseband signals on a time axis. Then, radio device 200 (FFT unit 403) converts the N sequence reception baseband signals on the time axis into N sequence reception signals on a frequency axis by FFT. Furthermore, radio device 200 (antenna weight multiplication unit 405) multiplies the N sequence reception signals on the frequency axis by a receiving antenna weight matrix of M rows and N columns (a vector when M is 1). As a result, an M sequence reception signal (i.e., an M layer reception signal) is output and transmitted to digital device 100.

[0070] For example, as described above, the signal transmitted from wireless device 200 to digital device 100 is not an N-sequence received signal but an M-sequence received signal (M-layer received signal). Therefore, even if the number of antennas N increases, the bandwidth of the interface between digital device 100 and wireless device 200 can be suppressed.

[0071] Digital device 100 (demodulation unit 407 and decoding unit 409) demodulates and decodes the received M-sequence signal (i.e., the received M-layer signal). For example, the decoded information is transmitted from digital device 100 to another device and processed by the other device. Alternatively, the decoded information may be further processed by digital device 100.

[0072] For example, the transceiver unit 401 in Fig. 8 is included in the first interface 210 in Fig. 7, and the FFT unit 403 and the antenna weight multiplication unit 405 in Fig. 8 are included in the wireless communication processing unit 241 in Fig. 7. Also, for example, the demodulation unit 407 and the decoding unit 409 in Fig. 8 are included in the wireless communication processing unit 131 in Fig. 6.

[0073] For example, as described above, the digital device 100 and the wireless device 200 perform reception processing of the physical layer (also called layer 1). That is, the wireless device 200 performs part of the reception processing of the physical layer, and the digital device 100 performs the remaining reception processing of the physical layer.

[0074] -Transmission process For example, the digital device 100 (wireless communication processing unit 131) performs encoding and modulation to generate a signal of one or more layers.

[0075] For example, particularly in the first embodiment, the wireless device 200 (wireless communication processing unit 241) multiplies the signals of one or more layers by transmitting antenna weights. Furthermore, the wireless device 200 (the first interface 210 and the wireless communication processing unit 241) transmits the signals generated by the multiplication of the transmitting antenna weights via the multiple antennas 300. The transmitting antenna weights can also be called, for example, (transmitting) beamforming weights (i.e., weights for performing beamforming on the transmitting side).

[0076] 8 again, digital device 100 (encoding section 421 and modulation section 423) encodes and modulates the transmission signal. As a result, an L sequence transmission signal (L layer transmission signal) is output and transmitted to wireless device 200.

[0077] Radio device 200 (antenna weight multiplication unit 425) multiplies the L sequence transmission signals by a transmitting antenna weight matrix with N rows and L columns, thereby generating N sequence transmission signals on the frequency axis. Then, radio device 200 (IFFT unit 427) converts the N sequence transmission signals on the frequency axis into N sequence baseband signals on the time axis by IFFT. Furthermore, radio device 200 (transmission / reception unit 401) converts the N sequence baseband signals on the time axis into N sequence radio transmission signals. Then, the N sequence radio transmission signals are transmitted from the multiple antennas 300 (N antennas 300).

[0078] For example, as described above, the signal transmitted from digital device 100 to wireless device 200 is an L-sequence received signal (L-layer received signal) rather than an N-sequence received signal. Therefore, even if the number of antennas N increases, the bandwidth of the interface between digital device 100 and wireless device 200 can be suppressed.

[0079] For example, the encoding unit 421 and the modulation unit 423 in Fig. 8 are included in the wireless communication processing unit 131 in Fig. 6. For example, the antenna weight multiplication unit 425 and the IFFT unit 427 in Fig. 8 are included in the wireless communication processing unit 241 in Fig. 7, and the transmission / reception unit 401 in Fig. 8 is included in the first interface 210 in Fig. 7.

[0080] For example, as described above, the digital device 100 and the wireless device 200 perform transmission processing of the physical layer (also called layer 1). That is, the wireless device 200 performs part of the transmission processing of the physical layer, and the digital device 100 performs the remaining transmission processing of the physical layer.

[0081] (2) Receiving antenna weights Particularly in the first embodiment, the wireless device 200 (the transmission processing unit 243) transmits channel-related information regarding channels of signals received via the multiple antennas 300 to the digital device 100. The digital device 100 (the reception processing unit 133) receives the channel-related information from the wireless device 200.

[0082] For example, the digital device 100 (the generation unit 135) generates weight information regarding the receiving antenna weights based on the channel-related information.

[0083] Furthermore, the digital device 100 (transmission processing unit 137) transmits the weighting information to the wireless device 200. The wireless device 200 (reception processing unit 245) receives the weighting information from the digital device 100.

[0084] Thereafter, wireless device 200 (wireless communication processing unit 241) multiplies the signals received via the multiple antennas 300 by the receiving antenna weights.

[0085] (2-1) Signal The signals received via the multiple antennas 300 are uplink signals (ie, signals transmitted from the terminal equipment 40 to the base station 10).

[0086] (2-2) Channel-related information -channel For example, the channel is a channel between the terminal device 40 and the plurality of antennas 300 .

[0087] -First example: Reference signal For example, the channel-related information is a reference signal received via the multiple antennas 300. That is, the wireless device 200 (transmission processing unit 243) transmits the reference signal to the digital device 100. The reference signal is information used for channel estimation of the channel.

[0088] In this case, the digital device 100 (the generation unit 135) performs channel estimation based on the reference signal to calculate a channel estimation value. Then, the digital device 100 (the generation unit 135) generates the weight information based on the channel estimation value.

[0089] A first example of channel estimation and weight information generation will be described with reference to FIG. 9. FIG. 9 is an explanatory diagram for describing a first example of channel estimation and weight information generation of the first embodiment. With reference to FIG. 9, the wireless device 200 (transmission processing unit 243) transmits a reference signal (N-sequence reference signal) from the output of the FFT unit 403 (N-sequence received signal on the frequency axis) to the digital device 100, and the digital device 100 (reception processing unit 133) receives the reference signal. Then, the digital device 100 (channel estimation unit 411: generation unit 135) calculates a channel estimation value (N-sequence channel estimation value) by performing channel estimation based on the reference signal. Furthermore, the digital device 100 (antenna weight generation unit 413: generation unit 135) calculates receiving antenna weights (a receiving antenna weight matrix of M rows and N columns) based on the channel estimation value, and generates weight information related to the receiving antenna weights. Digital device 100 (transmission processing unit 137) transmits the weight information to wireless device 200, and wireless device 200 (reception processing unit 245) receives the weight information. Thereafter, wireless device 200 (wireless communication processing unit 241) sets the receiving antenna weights as weights to be multiplied by signals received via the multiple antennas 300. As a result, wireless device 200 (wireless communication processing unit 241) multiplies the signals received via the multiple antennas 300 by the receiving antenna weights.

[0090] According to this example, not only the antenna weight generation section 413 but also the channel estimation section 411 is not included in the wireless device 200 but is included in the digital device 100. Therefore, the circuit scale of the wireless device 200 can be made smaller.

[0091] The reference signal is, for example, a reference signal transmitted in a specific period in a time frame. FIG. 10 is an explanatory diagram for explaining an example of a reference signal of the first embodiment. Referring to FIG. 10, a repeated time frame 1001 and a specific period 1003 in the time frame 1001 are shown. For example, a reference signal 1011 is transmitted in the specific period 1003. For example, the signal pattern of the reference signal 1011 is constant in the entire band, and each user (each terminal device) transmits a reference signal in an assigned band of the entire band. This makes it easy to transmit a reference signal from the wireless device 200 to the digital device 100, for example. More specifically, for example, the wireless device 200 can extract only a reference signal from a received signal and transmit the reference signal to the digital device 100 even if it does not hold information for each user (terminal device). Note that the specific period 1003 is located at the end of the time frame 1001 as shown in FIG. 10, for example, but is not limited to this example. For example, the particular time period 1003 may be located at the beginning of the time frame 1001, or at a location other than the beginning or end of the time frame 1001. Additionally, the particular time period 1003 may be one contiguous period as shown in FIG. 10, or it may be two or more distributed periods.

[0092] As an example, the time frame is a radio frame, and the specific period is a specific symbol. That is, the reference signal is transmitted by a specific symbol in the radio frame. Note that, for example, one radio frame includes a predetermined number of subframes, and one subframe includes a predetermined number of symbols. Note that the time frame and the specific period are not limited to this example.

[0093] For example, the reference signal may be a Sounding Reference Signal (SRS), or a Demodulation Reference Signal (DMRS).

[0094] The base station 10 (digital device 100 and wireless device 200) may communicate in TDD (Time Division Duplex). In this case, for example, as shown in FIG. 11, the reference signal 1011 may be transmitted from the wireless device 200 to the digital device 100. Specifically, the wireless device 200 receives the reference signal 1011 and other signals 1013 (data signals, control signals, etc.) as wireless reception signals during the reception period 1021 (i.e., uplink period), but does not receive any signals during the transmission period 1023 (i.e., downlink period). Therefore, as shown in FIG. 11, the wireless device 200 may transmit the other signals (M-sequence signals) to the digital device 100 during the reception period 1021, and transmit the reference signal (N-sequence signals) to the digital device 100 during the subsequent transmission period 1023 (and part of the reception period 1021).

[0095] -Second example: Channel estimate The channel-related information may be a channel estimation value calculated by the wireless device 200 through channel estimation based on reference signals received via the multiple antennas 300. That is, the wireless device 200 may calculate a channel estimation value by performing channel estimation based on the reference signals, and transmit the channel estimation value to the digital device 100.

[0096] A second example of channel estimation and weight information generation will be described with reference to FIG. 12. FIG. 12 is an explanatory diagram for describing a second example of channel estimation and weight information generation of the first embodiment. With reference to FIG. 12, the wireless device 200 (channel estimation unit 411: wireless communication processing unit 241) performs channel estimation based on a reference signal (reference signal of N series) among the output (received signal of N series on the frequency axis) of the FFT unit 403, thereby calculating a channel estimation value (channel estimation value of N series). Then, the wireless device 200 (transmission processing unit 243) transmits the channel estimation value to the digital device 100, and the digital device 100 (receiving processing unit 133) receives the channel estimation value. Furthermore, the digital device 100 (antenna weight generation unit 413: generation unit 135) calculates receiving antenna weights (receiving antenna weight matrix of M rows and N columns) based on the channel estimation value, and generates weight information related to the receiving antenna weights. Since the subsequent processing is the same as the example of FIG. 9, a duplicated description will be omitted here.

[0097] According to this example, what is transmitted from the wireless device 200 to the digital device 100 is not the reference signal itself but the channel estimate. For example, the data amount of the channel estimate can be compressed by averaging the channel estimate on the frequency axis, etc. Therefore, the bandwidth of the interface between the wireless device 200 and the digital device 100 can be further reduced.

[0098] (2-3) Weight information As described above, the weight information is weight information related to the receiving antenna weights, for example, information indicating the receiving antenna weights.

[0099] As described above, the receiving antenna weights are weights by which the radio device 200 multiplies signals received via the multiple antennas 300. For example, the receiving antenna weights are weights by which the radio device 200 multiplies signals from the terminal device 40 received via the multiple antennas.

[0100] For example, as described above, the receiving antenna weights are a receiving antenna weight matrix with M rows and N columns (a vector when M is 1). In this case, the weight information is information indicating the receiving antenna weight matrix with M rows and N columns.

[0101] As a first example, the weight information includes information indicating each weight included in the receiving antenna weight. Specifically, for example, the receiving antenna weight is a receiving antenna weight matrix of M rows and N columns, and the weight information includes information indicating each element (weight) included in the receiving antenna weight matrix. That is, the weight information includes information indicating each of the M×N elements. This makes it possible to set the receiving antenna weight more flexibly, for example.

[0102] As a second example, the receiving antenna weight may be one receiving antenna weight set included in a plurality of predetermined receiving antenna weight sets, and the weight information may be an index indicating the one receiving antenna weight set. Specifically, for example, a plurality of receiving antenna weight sets and an index indicating each of the plurality of receiving antenna weight sets may be predefined as a codebook, and the weight information may be an index indicating one receiving antenna weight set in the codebook. This, for example, reduces the amount of information in the weight information.

[0103] (2-4) Information on the use of receive antenna weights For example, digital device 100 (transmission processing unit 137) transmits the weight information and information on the use of the receiving antenna weights (hereinafter referred to as "use information") to wireless device 200. This enables wireless device 200 to actually perform the multiplication of the receiving antenna weights, for example.

[0104] -Frequency information For example, the usage information includes frequency information regarding a frequency at which the receiving antenna weight is used. For example, the frequency at which the receiving antenna weight is used is a frequency assigned to the terminal device 40. That is, the frequency information is information regarding a frequency assigned to the terminal device 40.

[0105] For example, the frequency information indicates a frequency block in which the receiving antenna weight is used among a plurality of frequency blocks. In other words, the frequency information indicates a frequency block in which a signal to be multiplied by the plurality of antenna weights is transmitted. The frequency information may indicate one frequency block or may indicate a plurality of frequency blocks. For example, the frequency block is a resource block (or a resource block group).

[0106] Additionally / alternatively, the frequency information may indicate a frequency resolution of the receive antenna weights, in other words, a frequency width (unit width) in which the receive antenna weights are used.

[0107] Such frequency information enables, for example, wireless device 200 to know at which frequency a signal transmitted should be multiplied by the receiving antenna weight.

[0108] -Time information For example, the usage information includes time information regarding a time when the receiving antenna weight is used. For example, the time when the receiving antenna weight is used is a time assigned to the terminal device 40. That is, the time information is information regarding a time assigned to the terminal device 40.

[0109] For example, the time information indicates a period during which the receiving antenna weights are used. In other words, the time information indicates a period during which a signal to be multiplied by the antenna weights is transmitted. The period may be a subframe or a slot. However, the period is not limited to these examples.

[0110] Such timing information allows, for example, wireless device 200 to know when to multiply a transmitted signal by the receive antenna weights.

[0111] The frequency information and the time information may be radio resource information (which may also be referred to as resource allocation information or scheduling information) regarding radio resources for which the receive antenna weights are used.

[0112] As described above, wireless device 200 transmits the channel-related information to digital device 100, and digital device 100 generates the weight information related to the receiving antenna weights based on the channel-related information, and transmits the weight information to wireless device 200. Then, wireless device 200 multiplies the signals received via the multiple antennas 300 by the receiving antenna weights. In this way, since the generation of the weight information (calculation of the receiving antenna weights) is performed by digital device 100, not wireless device 200, the circuit scale of wireless device 200 can be suppressed.

[0113] (3) Processing flow - Wireless communication processing An example of wireless communication processing according to the first embodiment will be described with reference to Fig. 13. Fig. 13 is a sequence diagram for explaining an example of a schematic flow of wireless communication processing according to the first embodiment.

[0114] The wireless device 200 receives signals via multiple antennas 300 (S501).

[0115] The wireless device 200 multiplies the signals received via the multiple antennas 300 by receiving antenna weights (S503). As a result, for example, signals of one or more layers are generated.

[0116] The wireless device 200 transmits the one or more layer signals to the digital device 100 (S505).

[0117] The digital device 100 demodulates and decodes the one or more layer signals (S507).

[0118] -Transmitting and receiving channel-related information and weighting information An example of a process of transmitting and receiving channel associated information and weight information according to the first embodiment will be described with reference to Fig. 14. Fig. 14 is a sequence diagram for explaining an example of a schematic flow of a process of transmitting and receiving channel associated information and weight information according to the first embodiment.

[0119] The wireless device 200 receives signals via multiple antennas 300 (S521).

[0120] The wireless device 200 transmits channel-related information regarding channels of signals received via the multiple antennas 300 to the digital device 100, and the digital device 100 receives the channel-related information (S523).

[0121] The digital device 100 generates weight information for the receiving antenna weights based on the channel-related information (S525).

[0122] The digital device 100 transmits the weighting information to the wireless device 200, and the wireless device 200 receives the weighting information (S527).

[0123] The wireless device 200 sets the receiving antenna weights as weights by which the signals received via the multiple antennas 300 are multiplied (S529).

[0124] <3.5. Modifications> As described above, in the first embodiment, the digital device 100 (the transmission processing unit 137) Weight information relating to receiving antenna weights by which wireless device 200 multiplies signals received via multiple antennas 300 is transmitted to wireless device 200. Wireless device 200 (reception processing unit 245) receives the weight information from digital device 100.

[0125] -First example In a modification of the first embodiment, for example, digital device 100 (transmission processing unit 137) may also transmit to wireless device 200 other weight information related to transmitting antenna weights used by wireless device 200 to generate signals to be transmitted via the multiple antennas 300. Then, wireless device 200 (reception processing unit 245) may receive the other weight information from digital device 100. For example, digital device 100 (generation unit 135) may generate the other information based on the channel-related information.

[0126] The transmit antenna weights may be a transmit antenna weight matrix with N rows and L columns (a vector when L is 1).

[0127] The other weight information regarding the transmitting antenna weights may be information in the same format as the weight information regarding the receiving antenna weights.

[0128] The wireless device 200 (wireless communication processing unit 241) may set the transmitting antenna weights based on the other weight information. Then, the wireless device 200 (wireless communication processing unit 241) may generate signals to be transmitted via the multiple antennas 300 by multiplying one or more layer signals (e.g., L layer signals) by the transmitting antenna weights.

[0129] -Second example Alternatively, the receiving antenna weights may be antenna weights used by the wireless device 200 to generate signals to be transmitted via the multiple antennas. That is, the receiving antenna weights and the transmitting antenna weights may be the same. For example, when the number of transmitting layers L and the number of receiving layers M are the same, the receiving antenna weights and the transmitting antenna weights may be the same in this way.

[0130] Regardless of whether it is the first example or the second example, particularly in the first modified example, the base station 10 (the digital device 100 and the wireless device 200) may perform communication in TDD.

[0131] The above describes the first embodiment. According to the first embodiment, both the circuit scale of the wireless device 200 and the bandwidth of the interface between the wireless device 200 and the digital device 100 can be reduced.

[0132] <<4. Second embodiment>> Next, a second embodiment of the present invention will be described with reference to Figures 15 to 17. The first embodiment described above is a specific embodiment, but the second embodiment is a more generalized embodiment.

[0133] <4.1. System configuration> First, an example of the configuration of a system 2 according to the second embodiment will be described with reference to Fig. 15. Fig. 15 is an explanatory diagram showing an example of a schematic configuration of a system 2 according to the second embodiment. Referring to Fig. 15, the system 2 includes a first communication device 600, a second communication device 700, and a plurality of antennas 800.

[0134] For example, the system 2 is a base station. The explanation of the base station is the same as the explanation of the base station 10 in the first embodiment, for example. Therefore, the overlapping explanation will be omitted here.

[0135] -First communication device 600 and second communication device 700 For example, each of the first communication device 600 and the second communication device 700 is one of a plurality of devices constituting a base station. The system 2 (base station) may further include other devices (not shown) other than the first communication device 600 and the second communication device 700 (and the plurality of antennas 800).

[0136] The second communication device 700 is a device physically separated from the first communication device 600. For example, the second communication device 700 is connected to a plurality of antennas 800, and 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 by 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 (optical fiber cable). Also, for example, the first communication device 600 is installed indoors, and the second communication device 700 is installed outdoors.

[0137] When the base station (system 2) includes the first unit and the second unit (see the first embodiment), the first communication device 600 may be the first unit (e.g., a DU (Digital Unit) or a BBU), and the second communication device 700 may be the second unit (e.g., a RU (Remote / Radio Unit), an RRH, or an RRU). Alternatively, the first communication device 600 and the second communication device 700 may be devices included in the second unit (e.g., a DU (Distributed Unit)).

[0138] --Multiple Antennas 800 For example, each of the plurality of antennas 800 is an antenna element included in a multi-element antenna, for example, an antenna for massive MIMO.

[0139] The configuration of the system 2 has been described above. As an example, the first communication device 600 may be the digital device 100 of the first embodiment, the second communication device 700 may be the wireless device 200 of the first embodiment, and the above-mentioned multiple antennas 800 may be the multiple antennas 300 of the first embodiment. Of course, the second embodiment is not limited to this example. As an example, the first communication device 600 may be a device (part / module) included in the digital device 100 of the first embodiment, and the second communication device 700 may be a device (part / module) included in the wireless device 200 of the first embodiment. As another example, the second communication device 700 may be a wireless device, but the first communication device 600 may be a third device other than the digital device.

[0140] <4.2. Configuration of the first communication device> Next, an example of the configuration of the first communication device 600 according to the second embodiment will be described with reference to Fig. 16. Fig. 16 is a block diagram showing an example of a schematic configuration of the first communication device 600 according to the second embodiment. Referring to Fig. 16, the first communication device 600 includes a reception processing unit 610 and a transmission processing unit 620.

[0141] The specific operations of the reception processing unit 610 and the transmission processing unit 620 will be described later.

[0142] The reception processing unit 610 and the transmission processing unit 620 may be implemented by one or more processors (such as a BB processor and / or other types of processors) and memories.

[0143] The first communication device 600 may include a memory that stores 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 the operations of the reception processing unit 610 and the transmission processing unit 620. The program may be a program for causing the processor to perform the operations of the reception processing unit 610 and the transmission processing unit 620.

[0144] Of course, the first communication device 600 may further include components other than the reception processing unit 610 and the transmission processing unit 620. For example, the first communication device 600 may further include components (e.g., the interface 110, the storage unit 120, the wireless communication processing unit 131, and / or the generation unit 135) included in the digital device 100 of the first embodiment.

[0145] <4.3. Configuration of the second communication device> Next, an example of the configuration of the second communication device 700 according to the second embodiment will be described with reference to Fig. 17. Fig. 17 is a block diagram showing an example of a schematic configuration of the second communication device 700 according to the second embodiment. Referring to Fig. 17, the second communication device 700 includes a wireless communication processing unit 710, a transmission processing unit 720, and a reception processing unit 730.

[0146] The specific operations of the wireless communication processing unit 710, the transmission processing unit 720, and the reception processing unit 730 will be described later.

[0147] The wireless communication processing unit 710, the transmission processing unit 720, and the reception processing unit 730 may be implemented by one or more processors (such as a BB processor and / or other types of processors) and memories.

[0148] The second communication device 700 may include a memory that stores a program (instruction) and one or more processors capable of executing the program (instruction). The one or more processors may execute the program to perform the operations of the wireless communication processing unit 710, the transmission processing unit 720, and the reception processing unit 730. The program may be a program for causing the processor to perform the operations of the wireless communication processing unit 710, the transmission processing unit 720, and the reception processing unit 730.

[0149] Naturally, the second communication device 700 may further include components other than the wireless communication processing unit 710, the transmission processing unit 720, and the reception processing unit 730. For example, the second communication device 700 may further include components (e.g., the first interface 210, the second interface 220, and / or the storage unit 230) included in the wireless device 200 of the first embodiment.

[0150] <4.4. Technical features> Next, the technical features of the second embodiment will be described.

[0151] (1) Wireless communication processing The second communication device 700 (wireless communication processing unit 710) receives signals via a plurality of antennas 800. Furthermore, in particular in the second embodiment, the second communication device 700 (wireless communication processing unit 710) multiplies the signals received via the plurality of antennas 800 by receiving antenna weights.

[0152] The description of such wireless communication processing (reception processing) is the same as, for example, the description of the wireless communication processing (reception processing) of the first embodiment. The description of the transmission processing may also be the same as the description of the transmission processing of the first embodiment. In this case, the second communication device 700 (wireless communication processing unit 710) may operate in the same manner as the wireless device 200 (wireless communication processing unit 241) of the first embodiment. The first communication device 600 may operate in the same manner as the digital device 100 (wireless communication processing unit 131) of the first embodiment. Therefore, duplicated descriptions will be omitted here.

[0153] Of course, the second embodiment is not limited to the above example. As an example, a device (digital device) other than the first communication device 600 may perform wireless communication processing.

[0154] (2) Receiving antenna weights In particular, in the second embodiment, the second communication device 700 (the transmission processing unit 720) transmits channel-related information regarding channels of signals received via the multiple antennas 800 to the first communication device 600. The first communication device 600 (the reception processing unit 610) receives the channel-related information from the second communication device 700.

[0155] Based on the channel-related information, weight information for the receive antenna weights is generated.

[0156] Furthermore, the first communication device 600 (the transmission processing unit 620) transmits the weighting information to the second communication device 700. The second communication device 700 (the reception processing unit 730) receives the weighting information from the first communication device 600.

[0157] Thereafter, the second communication device 700 (wireless communication processing unit 710) multiplies the signals received via the multiple antennas 800 by the receiving antenna weights.

[0158] The description of such receiving antenna weights is the same as, for example, the description of the receiving antenna weights in the first embodiment. In this case, the second communication device 700 (wireless communication processing unit 710, transmission processing unit 720, and reception processing unit 730) may operate in the same manner as the wireless device 200 (wireless communication processing unit 241, transmission processing unit 243, and reception processing unit 245) in the first embodiment. Also, the first communication device 600 (reception processing unit 610 and transmission processing unit 620) may operate in the same manner as the digital device 100 (reception processing unit 133 and transmission processing unit 137) in the first embodiment. Therefore, overlapping descriptions will be omitted here.

[0159] Of course, the second embodiment is not limited to the above example. As an example, a device other than the first communication device 600 may generate the weight information based on the channel-related information.

[0160] (3) Processing flow As an example, the process of the second embodiment is the same as the process of the first embodiment. Therefore, a duplicated description will be omitted here. It should be noted that the second embodiment is not limited to this example.

[0161] The second embodiment has been described above. According to the second embodiment, both the circuit scale of the second communication device 700 and the bandwidth of the interface between the second communication device 700 and another communication device (for example, the first communication device 600) can be suppressed. Note that the first modified example of the first embodiment may also be applied to the second embodiment.

[0162] Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. It will be understood by those skilled in the art that these embodiments are merely examples and that various modifications are possible without departing from the scope and spirit of the present invention.

[0163] For example, the steps in the processes described herein do not necessarily have to be performed chronologically in the order depicted in the sequence diagrams. For example, the steps in the processes may be performed in an order different from that depicted in the sequence diagrams, or may be performed in parallel. Also, some of the steps in the processes may be deleted, and additional steps may be added to the processes.

[0164] Also, a method including the operation / processing of the communication device (digital device, wireless device, first communication device, or second communication device) described in this specification may be provided, and a program for causing a processor to execute the operation / processing may be provided. Also, a non-transitory computer readable medium having the program recorded thereon may be provided. Naturally, such methods, programs, and non-transitory computer readable mediums are also included in the present invention.

[0165] A part or all of the above-described embodiments may be described as, but is not limited to, the following supplementary notes.

[0166] (Appendix 1) A first communication device, a reception processing unit that receives, from a second communication device that receives signals via a plurality of antennas, channel-related information relating to channels of the signals received via the plurality of antennas; a transmission processing unit that transmits to the second communication device weight information related to receiving antenna weights by which the second communication device multiplies signals received via the plurality of antennas, the weight information being generated based on the channel-related information; and A first communication device comprising:

[0167] (Appendix 2) The first communication device according to claim 1, wherein the weight information is information indicating the receiving antenna weight.

[0168] (Appendix 3) The first communication device according to claim 2, wherein the weight information includes information indicating each weight included in the receiving antenna weights.

[0169] (Appendix 4) the receiving antenna weight is one receiving antenna weight set included in a plurality of predetermined receiving antenna weight sets, The weight information is an index indicating the one receive antenna weight set. 3. A first communication device as described in claim 2.

[0170] (Appendix 5) The first communication device according to any one of Supplementary notes 1 to 4, wherein the transmission processing unit transmits the weight information and information regarding use of the receiving antenna weights to the second communication device.

[0171] (Appendix 6) 6. The first communication device of claim 5, wherein the information regarding use of the receiving antenna weights includes frequency information regarding frequencies at which the receiving antenna weights are used.

[0172] (Appendix 7) The first communication device according to claim 6, wherein the frequency information indicates a frequency block among a plurality of frequency blocks in which the receiving antenna weight is used.

[0173] (Appendix 8) 8. The first communication device according to claim 6 or 7, wherein the frequency information indicates a frequency resolution of the receiving antenna weights.

[0174] (Appendix 9) the channel is a channel between a terminal device and the plurality of antennas, the receiving antenna weights are weights by which the second communication device multiplies signals from the terminal device received via the multiple antennas, The frequency information is information regarding a frequency assigned to the terminal device. The first communication device according to any one of appendix 6 to 8.

[0175] (Appendix 10) 6. The first communication device of claim 5, wherein the information regarding use of the receiving antenna weights includes time information regarding a time when the receiving antenna weights are used.

[0176] (Appendix 11) the channel is a channel between a terminal device and the plurality of antennas, the receiving antenna weights are weights by which the second communication device multiplies signals from the terminal device received via the multiple antennas, The time information is information regarding a time assigned to the terminal device. 11. The first communication device of claim 10.

[0177] (Appendix 12) 12. The first communication device according to any one of claims 1 to 11, wherein the channel-related information is a reference signal received via the plurality of antennas.

[0178] (Appendix 13) The first communication device according to any one of appendixes 1 to 12, wherein the channel-related information is a channel estimation value calculated by the second communication device through channel estimation based on reference signals received via the multiple antennas.

[0179] (Appendix 14) 14. The first communication device according to claim 12 or 13, wherein the reference signal is a reference signal transmitted during a specific period within a time frame.

[0180] (Appendix 15) the time frame is a radio frame; The particular period is a particular symbol. 15. The first communication device of claim 14.

[0181] (Appendix 16) 16. The first communication device according to any one of appendixes 12 to 15, wherein the reference signal is a Sounding Reference Signal (SRS) or a Demodulation Reference Signal (DMRS).

[0182] (Appendix 17) The first communication device according to any one of claims 1 to 16, further comprising a generating unit configured to generate the weighting information based on the channel associated information.

[0183] (Appendix 18) The first communication device described in any one of Appendices 1 to 17, further comprising a wireless communication processing unit that performs demodulation and decoding of one or more layer signals generated by the second communication device multiplying the signals received via the multiple antennas by the receiving antenna weights.

[0184] (Appendix 19) The first communication device described in any one of Appendices 1 to 18, wherein the transmission processing unit transmits to the second communication device other weighting information regarding transmitting antenna weights used by the second communication device to generate signals to be transmitted via the multiple antennas, the other weighting information being generated based on the channel-related information.

[0185] (Appendix 20) The first communication device described in any one of Appendix 1 to 18, wherein the receiving antenna weights are antenna weights that are also used by the second communication device to generate signals to be transmitted via the multiple antennas.

[0186] (Appendix 21) The first communication device according to claim 19 or 20, wherein the second communication device is a device that performs communication in TDD (Time Division Duplex).

[0187] (Appendix 22) The first communication device according to any one of Supplementary Notes 1 to 21, wherein the signal is an uplink signal.

[0188] (Appendix 23) The first communication device according to any one of appendixes 1 to 22, wherein each of the first communication device and the second communication device is one of a plurality of devices constituting a base station.

[0189] (Appendix 24) the channel is a channel between a terminal device and the plurality of antennas, The receiving antenna weights are weights by which the second communication device multiplies signals from the terminal device received via the multiple antennas. A first communication device according to any one of appendixes 1 to 23.

[0190] (Appendix 25) The first communication device according to any one of appendixes 1 to 24, wherein each of the plurality of antennas is an antenna element included in a multi-element antenna.

[0191] (Appendix 26) The first communication device described in Appendix 25, wherein the multi-element antenna is an antenna for massive MIMO (Massive Multiple-Input and Multiple-Output).

[0192] (Appendix 27) the transmission processing unit receives the channel-associated information from the second communication device via a communication line; the receiving processing unit transmits the weighting information to the second communication device via the communication line. 27. A first communication device according to any one of claims 1 to 26.

[0193] (Appendix 28) 28. The first communication device described in Addendum 27, wherein the communication line is an optical fiber line.

[0194] (Appendix 29) The first communication device according to any one of Supplementary notes 1 to 28, wherein the second communication device is a device physically separated from the first communication device.

[0195] (Appendix 30) the second communication device is a device connected to the plurality of antennas; The first communication device is a device connected to the second communication device. 30. The first communication device according to any one of appendixes 1 to 29.

[0196] (Appendix 31) the first communication device is a device installed indoors, The second communication device is a device installed outdoors. The first communication device according to any one of appendixes 1 to 30.

[0197] (Appendix 32) a second communication device, a wireless communication processing unit for receiving signals via a plurality of antennas; a transmission processing unit configured to transmit channel-related information related to channels of signals received via the plurality of antennas to a first communication device; a reception processing unit that receives weight information related to reception antenna weights from the first communication device, the weight information being generated based on the channel-related information; Equipped with The wireless communication processing unit multiplies signals received via the plurality of antennas by the receiving antenna weights. A second communication device.

[0198] (Appendix 33) receiving, from a communication device receiving signals via a plurality of antennas, channel related information relating to channels of the signals received via the plurality of antennas; transmitting, to the communication device, weight information related to receive antenna weights by which the communication device multiplies signals received via the plurality of antennas, the weight information being generated based on the channel-related information; The method includes:

[0199] (Appendix 34) Receiving signals via a plurality of antennas; transmitting channel related information to a communication device regarding channels of signals received via the plurality of antennas; receiving weight information from the communication device relating to receive antenna weights, the weight information being generated based on the channel related information; multiplying signals received via the plurality of antennas by the receive antenna weights; The method includes:

[0200] (Appendix 35) receiving, from a communication device receiving signals via a plurality of antennas, channel related information relating to channels of the signals received via the plurality of antennas; transmitting, to the communication device, weight information related to receive antenna weights by which the communication device multiplies signals received via the plurality of antennas, the weight information being generated based on the channel-related information; A program that causes a processor to execute the following:

[0201] (Appendix 36) Receiving signals via a plurality of antennas; transmitting channel related information to a communication device regarding channels of signals received via the plurality of antennas; receiving weight information from the communication device relating to receive antenna weights, the weight information being generated based on the channel related information; multiplying signals received via the plurality of antennas by the receive antenna weights; A program that causes a processor to execute the following:

[0202] (Appendix 37) receiving, from a communication device receiving signals via a plurality of antennas, channel related information relating to channels of the signals received via the plurality of antennas; transmitting, to the communication device, weight information related to receive antenna weights by which the communication device multiplies signals received via the plurality of antennas, the weight information being generated based on the channel-related information; A non-transitory computer-readable recording medium having recorded thereon a program for causing a processor to execute the above.

[0203] (Appendix 38) Receiving signals via a plurality of antennas; transmitting channel related information to a communication device regarding channels of signals received via the plurality of antennas; receiving weight information from the communication device relating to receive antenna weights, the weight information being generated based on the channel related information; multiplying signals received via the plurality of antennas by the receive antenna weights; A non-transitory computer-readable recording medium having recorded thereon a program for causing a processor to execute the above.

[0204] (Appendix 39) A first communication device; A second communication device; and Including, The second communication device is Receives signals through multiple antennas, transmitting channel-related information to the first communication device regarding channels of signals received via the plurality of antennas; The first communication device is receiving the channel-related information from the second communication device; transmitting weight information relating to receiving antenna weights to the second communication device, the weight information being generated based on the channel related information; The second communication device is receiving the weight information from the first communication device; multiplying the signals received via the multiple antennas by the receive antenna weights; system.

[0205] (Appendix 40) In the second communication device, Receiving signals via a plurality of antennas; transmitting channel related information to a first communication device regarding channels of signals received via the plurality of antennas; In the first communication device, receiving the channel associated information from the second communication device; transmitting weight information relating to receiving antenna weights to the second communication device, the weight information being generated based on the channel related information; In the second communication device, receiving the weight information from the first communication device; multiplying signals received via the plurality of antennas by the receive antenna weights; The method includes:

[0206] This application claims priority based on Japanese Patent Application No. 2017-055726, filed March 22, 2017, the disclosure of which is incorporated herein in its entirety. [Industrial Applicability]

[0207] In a mobile communication system, it is possible to reduce both the circuit scale of a device that receives a signal via an antenna and the bandwidth of an interface between devices. [Explanation of symbols]

[0208] 1, 2 System 10 base station 21, 23 Communication lines 40 Terminal Equipment 100 Digital Devices 131 Wireless communication processing unit 133, 610 Receiving processing unit 135 Generation part 137, 620 Transmission processing unit 200 Radio equipment 241, 710 Wireless communication processing unit 243, 720 Transmission processing unit 245, 730 Receiving processing section 300, 800 Antennas 411 Channel Estimation Unit 413 Antenna Weight Generation Unit 600 First communication device 700 Second communication device 1001 Time Frames 1003 Specific period 1011 Reference Signal

Claims

1. A first communication device, from a second communication device receiving a signal via an antenna; receiving a signal other than a reference signal transmitted from the terminal device to the second communication device during a first time portion of a first period during which the second communication device receives an uplink signal from the terminal device in a radio frame; a reception processing unit that receives the reference signal during a second time portion of the first period that does not include the first time portion and during a second period in which the second communication device transmits a downlink signal to the terminal device; A channel estimation unit that performs channel estimation based on the reference signal; a transmission processing unit that transmits, to the second communication device, weight information regarding a receiving antenna weight by which the second communication device multiplies a signal received via the antenna; Equipped with The receiving antenna weights are used by the second communication device to perform beamforming at the receiving side. A first communication device.

2. The transmission processing unit transmits other weight information related to transmitting antenna weights to the second communication device; The other weight information regarding the transmitting antenna weights is information of the same format as the weight information regarding the receiving antenna weights. The first communication device according to claim 1 .

3. The weight information includes information indicating each weight included in the receiving antenna weights. A first communication device according to claim 1 or 2.

4. the receiving antenna weight is one receiving antenna weight set included in a plurality of predetermined receiving antenna weight sets, The weight information is an index indicating one of the receive antenna weight sets. A first communication device according to claim 1 or 2.

5. The weight information is generated based on a channel estimation value calculated in the channel estimation. A first communication device according to any one of claims 1 to 4.

6. the reference signal is a reference signal transmitted during a specific period within a time frame; A first communication device according to any one of claims 1 to 5.

7. a second communication device, a wireless communication processing unit for receiving signals via a plurality of antennas; to a first communication device, In a first time portion of a first period during which the second communication device receives an uplink signal from a terminal device in a radio frame, a signal other than a reference signal transmitted from the terminal device to the second communication device is transmitted for use in channel estimation performed by the first communication device; a transmission processing unit that transmits the reference signal during a second time portion of the first period that does not include the first time portion and during a second period in which the second communication device transmits a downlink signal to the terminal device; a reception processing unit that receives weight information related to reception antenna weights from the first communication device; Equipped with The wireless communication processing unit multiplies signals received via the plurality of antennas by the receiving antenna weights; The receiving antenna weights are used by the second communication device to perform beamforming at the receiving side. A second communication device.

8. From a communication device receiving signals via multiple antennas, receiving a signal other than a reference signal transmitted from the terminal device to the communication device during a first time portion of a first period during which the communication device receives an uplink signal from the terminal device in a radio frame; receiving the reference signal during a second time portion of the first time period that does not include the first time portion and during a second time period in which the communication device transmits a downlink signal to the terminal device; performing channel estimation based on the reference signal; transmitting, to the communication device, weight information regarding receiving antenna weights by which the communication device multiplies signals received via the plurality of antennas; Including, The receiving antenna weights are used by the communication device to perform beamforming at the receiving side. method.

9. A first communication device; A second communication device; Including, The second communication device is Receives signals through multiple antennas, to a first communication device, In a first time portion of a first period during which the second communication device receives an uplink signal from a terminal device in a radio frame, a signal other than a reference signal transmitted from the terminal device to the second communication device is transmitted for use in channel estimation performed by the first communication device; Transmitting the reference signal during a second time portion of the first period that does not include the first time portion and during a second period in which the second communication device transmits a downlink signal to the terminal device; The first communication device is from the second communication device, receiving the other signal that is not the reference signal during the first time portion of the first period during which the second communication device receives an uplink signal from the terminal device in a radio frame; receiving the reference signal during the second time portion of the first period that does not include the first time portion and during the second period in which the second communication device transmits a downlink signal to the terminal device; performing channel estimation based on the reference signal; transmitting weight information regarding receive antenna weights to the second communication device; The second communication device is receiving the weight information from the first communication device; multiplying the signals received via the plurality of antennas by the receiving antenna weights; The receiving antenna weights are used by the second communication device to perform beamforming at the receiving side. system.

Images