Mobile communication network with reconfigurable reflecting surface

Abstract

A remote transceiver for a mobile communication network is disclosed. The remote transceiver includes an antenna, a reconfigurable reflective surface comprising an array of conductive elements disposed on a two-dimensional substrate, and a data processing unit. The data processing unit directs user data to a user data guiding antenna addressing a mobile user equipment located within the coverage area of ​​the remote transceiver, and directs configuration data for adjusting its radiation pattern (and therefore its reflection angle) to the reconfigurable reflective surface. The antenna of the remote transceiver then transmits user data to the mobile user equipment located within the coverage area of ​​the remote transceiver, while the reconfigurable reflective surface of the same remote transceiver reflects radio signals carrying additional user data exchanged between another remote transceiver and other mobile user equipment within its coverage area, according to the radiation pattern adjusted based on the configuration data.

Description

Technical Field

[0001] This invention relates to the field of communication networks. In particular, this invention relates to implementing one or more reconfigurable reflective surfaces in mobile communication networks. Background Technology

[0002] As is known, a mobile communication network is a wireless telecommunications network distributed across land areas called cells, each cell being served by fixed-location equipment called a base station. Each base station provides radio coverage for its corresponding cell, which can be used for the transmission of voice, data, and various types of content.

[0003] Since its introduction, mobile communication networks have evolved over time, resulting in several generations of mobile networks based on different and increasingly powerful technologies, namely GSM, UMTS, LTE, and 5G NR (New Radio). Depending on the technology on which the mobile communication network is based, base stations can be named differently, such as BTS in GSM, NodeB in UMTS, eNodeB in LTE, or gNodeB in 5G NR.

[0004] Current base stations typically have a split architecture, including a central unit and multiple remote transceivers connected to the central unit. Each remote transceiver in a base station (also known as a remote radio head (RRH), remote radio unit (RRU), or remote unit (RU)) includes an antenna that transmits and receives radio signals to and from mobile user equipment located within a corresponding portion of the cell (hereinafter referred to as the "coverage area of ​​the remote transceiver"). Depending on the technology employed, the remote transceiver may also be responsible for performing a portion of the base station's radio signal processing functions.

[0005] Furthermore, reconfigurable reflective surfaces (also known as RIS, or reconfigurable smart surfaces) are known. A reconfigurable reflective surface is a reflective surface whose radiation pattern (and therefore its reflection angle(s)) can be adjusted by modifying the electrical and magnetic properties of the surface. From a structural perspective, a reconfigurable reflective surface is an array of subwavelength conductive elements arranged on a two-dimensional substrate. The electrical and magnetic properties of the surface are adjusted by modifying the phase shift introduced by each conductive element. Reconfigurable reflective surfaces typically have a controller that is responsible for adjusting the phase shift introduced by each conductive element, and thus adjusting its radiation pattern, i.e., its reflection angle(s).

[0006] It is known to place reconfigurable reflective surfaces in the radio channel between a transmitter and a receiver. By guiding radio signals toward the receiver, reconfigurable reflective surfaces can improve the transmission characteristics of the radio channel. For the same purpose, the use of reconfigurable reflective surfaces has also been proposed in mobile communication networks.

[0007] Figure 1 A remote transceiver 2 is shown for a mobile radio network with a certain coverage area 2a. Two mobile user equipments 21 and 22 are located within the coverage area 2a. When mobile user equipment 21 is in line of sight with the remote transceiver 2 (see...), Figure 1 As indicated by arrow A1, a large obstacle 3 (e.g., a group of buildings) obstructs the propagation of radio signals in the line of sight between mobile user equipment 22 and remote transceiver 2. This may result in poor transmission characteristics of the radio channel between mobile user equipment 22 and remote transceiver 2.

[0008] To improve the transmission characteristics of the radio channel, a reconfigurable reflective surface 1 can be placed at a certain distance from the remote transceiver 2, guiding the radio signals between the remote transceiver 2 and the mobile user equipment 22, such as... Figure 1 Arrow A2 in the diagram schematically indicates that, in order to properly adjust the radiation pattern of the reconfigurable reflective surface (and thus the reflection angle), its controller ( Figure 1 (Not shown in the diagram) Utilizing a dedicated wired or wireless control link ( Figure 1 (Not shown in the diagram) Connected to the central unit of the base station containing the remote transceiver 2. When the reconfigurable reflective surface is properly configured, its guiding effect essentially ensures radio coverage throughout the entire coverage area 2a, including the blind spot behind the obstacle 3 where the mobile user equipment 22 is located.

[0009] Reconfigurable reflective surfaces in mobile communication networks are typically implemented as stand-alone devices physically separate from base stations and other components of the mobile communication network. For example, in Figure 1 In this configuration, the remote transceiver 2 is fixed to the lamp post 2b, while the reconfigurable reflective surface 1 is fixed to another lamp post 1b located at a certain distance from the lamp post 2b. Summary of the Invention

[0010] The applicant has noted some drawbacks to implementing reconfigurable reflective surfaces as stand-alone devices in mobile communication networks.

[0011] First, suitable physical supports (such as building facades, billboards, lampposts, etc.) must be found in appropriate locations for each reconfigurable reflective surface.

[0012] Furthermore, each reconfigurable reflective surface should be powered. While the reconfigurable reflective surface itself is indeed a passive component, its controller needs to be powered. In addition to the controller, the reconfigurable reflective surface may also contain other active components that require power. For example, the reconfigurable reflective surface may incorporate active components for RF processing and / or baseband processing for purposes such as channel estimation and / or RF amplification of reflected radio signals.

[0013] In addition, a control link (wireless or wired) should be provided between the controller of each reconfigurable reflective surface and the base station of the mobile communication network, which enables communication between the controller and the base station so that the controller can properly adjust the radiation pattern of the reconfigurable reflective surface (and thus adjust the reflection angle).

[0014] While providing physical support, power, and control links for a single reconfigurable reflector may not pose significant problems, these operations can create deployment challenges in scenarios with high cell density, where several reconfigurable reflectors will be deployed. These issues become particularly acute when radio signal carrier frequencies are in the millimeter-wave band (i.e., between 30 GHz and 300 GHz) or the Asia-Pacific Hertz band (i.e., between 90 GHz and 300 GHz). Such high carrier frequencies necessitate cell sizes reduced to 200 meters or less (in which case the cell is referred to as a "peculiar cell"); the corresponding increase in cell density makes providing structural support, power, and control links for each reconfigurable reflector much more difficult.

[0015] In view of the above, the applicant has solved the problem of providing a reconfigurable reflective surface in a mobile communication network, which solves the above-mentioned disadvantages.

[0016] In particular, the applicant has addressed the problem of providing an implementation of a reconfigurable reflective surface in a mobile communication network that minimizes deployment problems caused by the need to provide physical support, power and control links for the surface, making the implementation of the reconfigurable reflective surface feasible in scenarios with high cell density where several surfaces should be deployed (e.g., when the carrier frequency is in the millimeter wave band or the Asia-Pacific Hertz band).

[0017] According to embodiments of the invention, this problem is solved by a remote transceiver for a mobile communication network (e.g., but not exclusively, a 5G mobile communication network) comprising an antenna, a reconfigurable reflective surface, and a data processing unit. The data processing unit is provided with user data carrying user traffic addressed to one or more mobile user equipments located within the coverage area of ​​the remote transceiver, and configuration data for adjusting the radiation pattern of the reconfigurable reflective surface; the data processing unit directs the user data to the antenna and the configuration data to the reconfigurable reflective surface; the antenna transmits the user data to one or more mobile user equipments located within the coverage area of ​​the remote transceiver; alternatively, the reconfigurable reflective surface reflects radio signals carrying additional user data exchanged between another remote transceiver and another mobile user equipment (one or more) located within another coverage area of ​​that other remote transceiver, according to the radiation pattern adjusted based on the configuration data.

[0018] Advantageously, since the reconfigurable reflective surface is contained within the transceiver, the reconfigurable reflective surface can utilize the physical support and power supply of the transceiver.

[0019] Furthermore, since the remote transceiver is already connected to the central unit of its base station via a link, the reconfigurable reflective surface can advantageously utilize this link to obtain the configuration data required to adjust its radiation pattern (and thus its reflection angle), thanks to the data processing unit that is able to distinguish the configuration data from the user data and direct them to the reconfigurable reflective surface.

[0020] Therefore, deployment issues arising from the need to provide physical support, power, and control links for reconfigurable reflective surfaces are advantageously minimized. Consequently, implementing reconfigurable reflective surfaces in each cell of a mobile communication network to ensure radio coverage of blind spots is also feasible in scenarios with high cell density where several surfaces should be deployed (e.g., when the carrier frequency is in the millimeter-wave band or the Asia-Pacific Hertz band).

[0021] In this regard, it should be noted that as the carrier frequency increases, the size of the reconfigurable reflective surface decreases, making it easier to integrate into a remote transceiver. For example, the applicant has noted that a reconfigurable reflective surface capable of reflecting radio signals with carrier frequencies in the millimeter-wave band or the Asia-Pacific Hertz band can comprise 256 reflective elements spaced at half-wavelengths (i.e., 16 × 16 reflective elements), resulting in a flat surface of size a × b, where a and b are both equal to approximately 10 cm. This size is advantageously compatible with the dimensions of the housing used for remote transceivers in the same carrier frequency range. The reconfigurable reflective surface can then be disposed on the surface of the housing of the remote transceiver, for example, adjacent to the antenna of the remote transceiver.

[0022] As another advantage, it is worth noting that remote transceivers typically include components for RF and / or baseband processing of radio signals transmitted and received by their own antennas. Integrating a reconfigurable reflective surface into the remote transceiver then advantageously allows that surface to utilize a portion of these components for its own purposes, such as channel estimation.

[0023] According to a first aspect, the present invention provides a remote transceiver for a mobile communication network, the remote transceiver comprising:

[0024] - Antenna;

[0025] - A reconfigurable reflective surface, comprising an array of conductive elements arranged on a two-dimensional substrate; and

[0026] - A data processing unit is configured to direct user data to a user data guiding antenna located within the coverage area of ​​the remote transceiver, and to direct configuration data for adjusting the radiation pattern of a reconfigurable reflective surface to the reconfigurable reflective surface.

[0027] The antenna is configured to transmit user data to at least one mobile user equipment located within the coverage area of ​​the remote transceiver; and

[0028] The reconfigurable reflective surface is configured to reflect radio signals carrying additional user data exchanged between another remote transceiver and at least one additional mobile user equipment located in another coverage area of ​​that other remote transceiver, according to a radiation pattern adjusted based on configuration data.

[0029] Preferably, user data and configuration data are received by the data processing unit in data packets from the link of the central unit of the base station connecting the remote transceiver to the mobile communication network. Each data packet includes at least one field indicating the type of data carried by the data packet, and the data processing unit includes a demultiplexer configured to determine whether the data packet contains user data or configuration data based on the value of the at least one field.

[0030] Preferably, the configuration data includes a vector of reflection coefficients, each reflecting coefficient indicating an adjustable phase shift introduced by a corresponding conductive element of the reconfigurable reflective surface.

[0031] According to some embodiments, at least one of the reflection coefficients has an amplitude greater than 1, meaning that the reconfigurable reflective surface is an active surface.

[0032] Optionally, the data processing unit is configured to locally generate further configuration data for further adjusting the radiation pattern of the reconfigurable reflective surface, and direct the further configuration data to the reconfigurable reflective surface.

[0033] Preferably, the antenna and reconfigurable reflective surface are arranged on the surface of the transceiver housing.

[0034] Optionally, the reconfigurable reflective surface further includes at least one sensing device embedded in a conductive element of the reconfigurable reflective surface, and the transceiver further includes an RF switch and a baseband processing unit, the RF switch being configured to selectively connect the baseband processing unit to the antenna and the at least one sensing device, the baseband processing unit being configured to perform channel estimation on at least one pilot radio signal transmitted by the other transceiver or at least one additional mobile user equipment located in another coverage area of ​​the other transceiver when connected to the at least one sensing device.

[0035] According to a second aspect, the present invention provides a mobile communication network comprising a remote transceiver and another remote transceiver, wherein the remote transceiver includes:

[0036] - Antenna;

[0037] - A reconfigurable reflective surface, comprising an array of conductive elements arranged on a two-dimensional substrate; and

[0038] - A data processing unit is configured to direct user data to a user data guiding antenna located within the coverage area of ​​the remote transceiver, and to direct configuration data for adjusting the radiation pattern of a reconfigurable reflective surface to the reconfigurable reflective surface.

[0039] The antenna is configured to transmit user data to at least one mobile user equipment located within the coverage area of ​​the remote transceiver; and

[0040] The reconfigurable reflective surface is configured to reflect radio signals carrying additional user data exchanged between the other remote transceiver and at least one other mobile user equipment located in another coverage area of ​​the other remote transceiver, according to a radiation pattern adjusted based on configuration data.

[0041] Preferably, the remote transceiver and the other remote transceiver operate at a first carrier frequency f1 and a second carrier frequency f2, respectively, where the first carrier frequency f1 and the second carrier frequency f2 are higher than 5 GHz. For example, the first carrier frequency f1 and the second carrier frequency f2 can be between 7 GHz and 20 GHz. Alternatively, they can be between 24.25 GHz and 52.6 GHz, which corresponds to Frequency Range 2 (FR2) defined in 3GPP for applying NR at millimeter wave frequencies.

[0042] According to the embodiment, the first carrier frequency f1 is different from the second carrier frequency f2. Attached Figure Description

[0043] The invention will become clearer from the following detailed description, which is given by way of example and not limitation, and should be read with reference to the accompanying drawings, in which:

[0044] - Figure 1 (As described above) shows a portion of a mobile communication network including a reconfigurable reflective surface according to the prior art;

[0045] - Figure 2 A remote transceiver incorporating a reconfigurable reflective surface is shown according to an embodiment of the present invention;

[0046] - Figure 3 The embodiments according to the present invention are shown in more detail. Figure 2 Remote transceiver;

[0047] - Figure 4 This is according to an embodiment of the present invention. Figure 2 A perspective view of a remote transceiver;

[0048] - Figure 5 An embodiment according to the present invention is shown. Figure 2 The radiation pattern of the antenna contained in the remote transceiver;

[0049] - Figure 6 A portion of a remote transceiver according to another embodiment of the present invention is shown; and

[0050] - Figures 7 to 9 Three exemplary scenarios of applying a remote transceiver according to embodiments of the present invention are shown.

[0051] The attached diagram is not drawn to scale. Detailed Implementation

[0052] Figure 2 A remote transceiver 100 according to an embodiment of the present invention is shown.

[0053] The remote transceiver 100 includes an antenna 101, a reconfigurable reflective surface 102, and a data processing unit 103.

[0054] Antenna 101 is preferably configured to allow remote transceiver 100 to exchange user data with one or more mobile user equipments located within the coverage area of ​​remote transceiver 100. For this purpose, antenna 101 is preferably configured to transmit and receive radio signals having a certain carrier frequency f1. The carrier frequency f1 is preferably higher than 5 GHz. Antenna 101 is preferably an array antenna.

[0055] The reconfigurable reflective device 102 is configured to reflect radio signals carrying additional user data exchanged between another remote transceiver (i.e., a remote transceiver other than remote transceiver 100) and one or more additional mobile user equipment located in another coverage area of ​​that other remote transceiver. The radio signals reflected by the reconfigurable reflective device 102 preferably have a carrier frequency f2 higher than 5 GHz. The carrier frequency f2 may be equal to or different from the carrier frequency f1. The reconfigurable reflective device 102 comprises an array of subwavelength conductive elements arranged on a two-dimensional substrate. The radiation pattern of surface 102 can be adjusted by adjusting the phase shift introduced by each conductive element.

[0056] The data processing unit 103 is preferably connected to one end of a link 104, which connects the data processing unit 103 (and thus the remote transceiver 100) to a central unit of a base station (not shown in the figures) containing the remote transceiver 100. Within the remote transceiver 100, the data processing unit 103 is connected to both the antenna 101 and the reconfigurable reflector 102.

[0057] In the downstream direction (i.e., from the central unit to the remote transceiver 100), link 104 preferably carries different types of data, including:

[0058] - User data D1, carrying voice, data, and / or various types of content addressed to one or more mobile user equipments located within the coverage area of ​​remote transceiver 100; and

[0059] - Configuration data D2, used to adjust the radiation pattern of the reconfigurable reflective surface 102.

[0060] According to an embodiment of the present invention, the data processing unit 103 is configured to receive data D1 and D2 from the link 104 and separate them so as to direct user data D1 to the antenna 101 and configuration data to the reconfigurable reflective surface 102.

[0061] Antenna 101 then transmits user data D1 to one or more mobile user equipment located within the coverage area of ​​remote transceiver 100. Furthermore, the radiation pattern (and therefore its reflection angle) of the reconfigurable reflective surface 102 is adjusted based on configuration data D2.

[0062] Figure 3 A remote transceiver 100 according to an embodiment of the present invention is shown in more detail.

[0063] In addition to the components described above, the remote transceiver 100 also includes circuitry 105 configured to provide power to the active components of the remote transceiver 100, particularly to the data processing unit 103.

[0064] The data processing unit 103 preferably includes several functional blocks.

[0065] Specifically, the data processing unit 103 preferably includes an interface 1031, which is configured to manage the exchange of data between the remote transceiver 100 and the central unit of the base station via link 104, including the aforementioned data D1 and D2. If link 104 is an optical fiber link, then interface 1031 preferably performs electrical-to-optical conversion and vice versa of the data carried by link 104.

[0066] The data processing unit 103 preferably further includes a wireless electronics unit 1032 and a reconfigurable reflective surface control subunit 1033. The wireless electronics unit 1032 is connected to the antenna 101, while the reconfigurable reflective surface control subunit 1033 is connected to the reconfigurable reflective surface 102.

[0067] The data processing unit 103 preferably further includes a demultiplexer 1034, which has an input port connected to the interface 1031 and two output ports connected to the subunits 1032 and 1033.

[0068] Preferably, an RF module 106 is provided between the wireless electronic unit 1032 and the antenna 101, which includes a plurality of hardware components for hardware processing of radio signals to be transmitted by and received by the antenna 101. The RF module 106 preferably includes at least one of the following: an RF power amplifier for transmission, an RF low-noise amplifier for reception, a mixer for frequency up-conversion or down-conversion, an oscillator, an RF filter, a duplexer, etc.

[0069] Demultiplexer 1034 is a component in data processing unit 103 responsible for receiving data D1 and D2 from link 104 and directing them to antenna 101 and reconfigurable reflective surface 102, respectively. For example, data D1 and D2 can be received from link 104 within the payload of the respective data packets. The header of such data packets may include one or more dedicated fields whose values ​​indicate the data type carried in the payload, i.e., user data or configuration data. Demultiplexer 1034 can distinguish data D1 and D2 based on the values ​​of such fields in the header of each data packet received from link 104 (and then direct them to antenna 101 or reflective surface 102, respectively).

[0070] More specifically, demultiplexer 1034 receives data D1 and D2 through interface 1031 and forwards them to wireless electronic unit 1032 and reconfigurable reflector control subunit 1033, respectively. In addition to data D1 and D2, demultiplexer 1034 can also receive radio control data from link 104 for controlling and configuring wireless electronic unit 1032 and antenna 101; this data is also preferably forwarded to wireless electronic unit 1032.

[0071] The wireless electronic unit 1032 then processes the user data D1 and forwards it via the RF module 106 to the antenna 101, which transmits it to one or more mobile user equipment(s) addressed within the coverage area of ​​the remote transceiver 100. The wireless electronic unit 1032 preferably also uses radio control data (if available) to properly configure its own processing functions and the configuration parameters of the antenna 101.

[0072] The reconfigurable reflective surface control subunit 1033 alternatively processes the configuration data D2 to generate configuration commands for appropriately adjusting the phase shift introduced by each conductive element of the reconfigurable reflective surface 102, thereby adjusting its radiation pattern.

[0073] For example, in the case where the remote transceiver 100 is a RU in a 5G mobile communication network, link 104 is a fronthaul link that connects the remote transceiver 100 to the central unit via a DU (Distributed Unit). The DU is an intermediate component provided between the RU and the central unit according to the system architecture defined by 3GPP (3rd Generation Partnership Project) or the O-RAN (Open RAN) Alliance. In the latter case, interface 1031 is a fronthaul interface based on the Open Fronthaul (O-FH) interface protocol standardized by the O-RAN Alliance. This protocol specifically specifies that the user data D1 transmitted on link 104 is a quantized and compressed OFDM (Orthogonal Frequency Division Multiplexing) sample in the frequency domain.

[0074] In this configuration, the wireless electronic unit 1032 is preferably configured to perform all the functions provided by the 7-2x function split defined by the O-RAN Alliance. As is known, the 7-2x function split defines the division of various base station functions among the RU, DU, and central unit (CU) of the gNodeB. The functions to be performed by the RU (and therefore by the wireless electronic unit 1032) specifically include the lower part of the OFDM physical layer, namely precoding, digital beamforming, IFFT (Inverse Fast Fourier Transform), digital-to-analog conversion (DAC), and analog beamforming.

[0075] For the configuration data D2, it can include the value of the reflection coefficient for each element of the reflective surface 102. The reflection coefficient of the nth element of the reflective surface 102 can be mathematically expressed as... ,in It is an adjustable phase shift, and This is an adjustable amplitude factor introduced on the electromagnetic signal reflected by the nth element of the reflective surface 102. If the reflective surface 102 is a passive reflective surface, then the maximum value of the amplitude factor is 1. If, alternatively, the reflective surface 102 is active (i.e., it can also amplify the reflected signal), then the amplitude factor can be greater than 1. The configuration data D2 can include real-time configuration data and non-real-time configuration data. Non-real-time configuration data can be generated by a management server dedicated to managing the reconfigurable reflective surface 102 and other reconfigurable reflective surfaces deployed in the mobile communication network. Real-time configuration data can alternatively be generated by the base station containing the remote transceiver 100 itself, for example, by a DU connected to the remote transceiver 100 via link 104. Other real-time configuration data can be generated locally autonomously by the remote transceiver 100 itself (particularly by its reconfigurable reflective surface control subunit 1033).

[0076] In any case, the transmission of configuration data D2 via link 104 can be performed by extending the Open Fronthaul (O-FH) interface protocol standardized by the O-RAN Alliance. Specifically, the O-FH protocol (or any other protocol generally used to connect transceiver 100 to DU) can be extended to include a reflection vector carrying reflective surface 102. One or more fields.

[0077] Advantageously, since the reconfigurable reflective surface 102 is included in the remote transceiver 100, the reconfigurable reflective surface 102 can utilize the physical support and power supply of the remote transceiver 100.

[0078] Furthermore, since the remote transceiver 100 is already connected to the central unit of its base station via link 104, the reconfigurable reflective surface 102 can advantageously utilize link 104 to obtain the configuration data D2 required to adjust its radiation pattern (and thus its reflection angle), thanks to the data processing unit 103 (in particular multiplexer 1034) that is able to distinguish the configuration data D2 received via link 104 from the user data D1 and direct them to the reconfigurable reflective surface 102.

[0079] Therefore, deployment issues arising from the need to provide physical support, power, and control links for the reconfigurable reflective surface 102 are advantageously minimized. Thus, implementing reconfigurable reflective surfaces in each cell of the mobile communication network to ensure radio coverage in blind spots is feasible even in scenarios with high cell density where several surfaces should be deployed (e.g., when the carrier frequency is in the millimeter-wave band or the Asia-Pacific Hertz band).

[0080] In this regard, it should be noted that as the carrier frequency increases, the size of the reconfigurable reflective surface 102 decreases, thus facilitating its integration within the transceiver 100. For example, the applicant has noted that a reconfigurable reflective surface capable of reflecting radio signals with carrier frequencies in the millimeter-wave band or the Asia-Pacific Hertz band can comprise 256 reflective elements spaced at half-wavelength intervals (i.e., 16 × 16 reflective elements), resulting in a flat surface with dimensions a × b, where a and b are both approximately 10 cm. This size is advantageously compatible with the dimensions of transceiver housings used in the same carrier frequency range.

[0081] The reconfigurable reflective surface 102 can then be disposed on the surface of the housing of the remote transceiver 100, for example, adjacent to the antenna 101, such as... Figure 4 and Figure 5 As shown in the image.

[0082] In particular, such as Figure 4 As shown, the remote transceiver 100 preferably includes a housing 107 that houses other components of the remote transceiver 100. The housing 107 is preferably made of a plastic material. The housing 107 preferably has a substantially parallelepiped shape.

[0083] The data processing unit 103, circuit 105, and RF module 106 are preferably housed within the housing 107 and Figure 4 It is not visible in the middle. Link 104 preferably exits the housing through the side of housing 107.

[0084] The antenna 101 and the reconfigurable reflective surface 102 are preferably arranged side-by-side on a substantially flat surface of the housing 107. Figure 5The Cartesian reference system xyz is schematically depicted in the diagram. According to... Figure 4 and Figure 5 In the embodiment shown, the antenna 101 and the reconfigurable reflective surface 102 are preferably aligned along the z-axis. When the remote transceiver 100 is fixed to its physical support (e.g., a lamppost), it is preferably arranged such that the z-axis is parallel to the vertical direction, such that the antenna 101 and the reconfigurable reflective surface 102 are arranged substantially stacked on top of each other.

[0085] To provide electromagnetic isolation between antenna 101 and reconfigurable reflective surface 102, the two elements are preferably arranged along the z-axis with a minimum mutual distance Lmin. This minimum mutual distance Lmin is preferably in the range of a few millimeters to a few centimeters.

[0086] In addition to or alternative to the above, the purpose of providing electromagnetic isolation between antenna 101 and the reconfigurable reflective surface 102 can be achieved by appropriately designing the radiation pattern of antenna 101. For example, the radiation pattern of antenna 101 can be designed to minimize radiation from antenna 101 to the reconfigurable reflective surface 102 (i.e., in...). Figure 4 and Figure 5 The amount of electromagnetic power along the z-axis in the depicted embodiment.

[0087] Figure 5 An exemplary radiation pattern of an antenna 101 that provides electromagnetic isolation between a reconfigurable reflective surface 102 and an antenna 101 is shown. Figure 5 Specifically, the radiation pattern of antenna 101 in a plane perpendicular to both antenna 101 and the reconfigurable reflective surface 102, and including the plane along their alignment directions, is shown. Figure 5 In the Cartesian reference system xyz shown, this plane corresponds to the xz plane. As is known, the radiation pattern shows the angular dependence of the electromagnetic power radiated by the antenna. Figure 5 As can be seen, the radiation pattern of antenna 101 exhibits a main lobe at 0° (corresponding to the x-axis), two symmetrical side lobes at approximately ±60°, and two nulls at ±90° (corresponding to the z-axis). The two nulls at ±90° mean that the amount of electromagnetic power radiated by antenna 101 to the reconfigurable reflective surface 102 (and in the opposite direction along the z-axis) is essentially zero, thus minimizing the interference of antenna 101 on the reconfigurable reflective surface 102.

[0088] The shape of the housing 107 and the arrangement of the antenna 101 and reflective surface 102 described above are not limiting. The housing 107 can indeed have shapes other than a parallelepiped, such as a cube. In this case, the antenna 101 and reflective surface 102 can be arranged on different faces of the cube. Furthermore, the remote transceiver 100 may include two or more reflective surfaces 102; all reflective surfaces 102 may be arranged on the same surface of the housing 107 or on different surfaces of the housing 107.

[0089] In addition to utilizing the link 104 and power supply 105 of the remote transceiver 100, the reconfigurable reflective surface 102 can also utilize other hardware / software resources of the remote transceiver 100 to perform additional functions, such as channel estimation and / or RF amplification of reflected radio signals.

[0090] Figure 6 A portion of a remote transceiver 100 is shown, illustrating an embodiment in which a reconfigurable reflective surface 102 utilizes a portion of the hardware / software resources of the remote transceiver 100 to provide channel estimation functionality.

[0091] According to this embodiment, the reconfigurable reflective surface 102 includes a plurality of sensing devices embedded in conductive elements of the reflective surface 102. Figure 6 (Not shown in the image). These sensing devices preferably include a low-power RF receiver chain with baseband processing capabilities that provide channel estimation by receiving pilot radio signals transmitted by another remote transceiver (in the downlink direction) or by a user terminal (in the uplink direction). When the reconfigurable reflective device 102 reflects radio signals carrying user data exchanged between another remote transceiver (i.e., a remote transceiver other than remote transceiver 100) and one or more mobile user equipments located in the coverage area of ​​that other remote transceiver, it also receives pilot radio signals from that other remote transceiver and / or from the one or more mobile user equipments located in the coverage area of ​​that other remote transceiver. Such pilot radio signals are detected by the sensing devices of the reconfigurable reflective surface 102 and can then be processed to perform channel estimation between surface 102 and the other remote transceiver, and / or between surface 102 and one or more mobile user equipments located in the coverage area of ​​that other remote transceiver.

[0092] according to Figure 6 In the embodiment shown, the remote transceiver 100 includes an RF switch 600 connected to both the antenna 101 and the reconfigurable reflective surface 102. The RF switch 600 may include, for example, a MEMS (microelectromechanical system).

[0093] The remote transceiver 100 preferably also includes an RF receiver 601, an analog-to-digital converter 602, and a baseband processing unit 603. The baseband processing unit 603 is capable of performing channel estimation functions and is connected to a reconfigurable reflective surface control subunit 1033.

[0094] According to this embodiment, the RF switch 600 is configured to alternately connect the antenna 101 and the reconfigurable reflective surface 102 (in particular its sensing device) to the RF receiver 601.

[0095] When antenna 101 is connected to RF receiver 601, RF receiver 601, analog-to-digital converter 602, and baseband processing unit 603 receive and process radio signals carrying user data received by antenna 101 from one or more mobile user equipment located within the coverage area of ​​remote transceiver 100. Specifically, baseband processing unit 603 performs channel estimation on such radio signals, the results of which can be used, for example, to adjust the parameters of wireless electronics unit 1032 and / or antenna 101 as needed.

[0096] When the reconfigurable reflective surface 102 (in particular its sensing device) is reconnected to the RF receiver 601, the RF receiver 601, the analog-to-digital converter 602, and the baseband processing unit 603 receive and process pilot radio signals received by the sensing device of the reconfigurable reflective surface 102 from the other remote transceiver or from one or more mobile user equipments located within the coverage area of ​​the other remote transceiver. Specifically, the baseband processing unit 603 performs channel estimation on such pilot radio signals. The results of such processing can be provided to the reconfigurable reflective surface control subunit 1033, which, based on these results, generates appropriate reconfiguration commands as needed to adjust the phase shift introduced by each conductive element of the reconfigurable reflective surface 102.

[0097] Therefore, according to this embodiment, the antenna 101 and the reconfigurable reflective surface 102 advantageously share the same RF receiver chain.

[0098] To enable such sharing, the remote transceiver 100 preferably exchanges user data with one or more mobile user equipment located in its coverage area by means of a TDD (Time Division Duplex) protocol, according to which downlink and uplink transmissions are allocated on different non-overlapping time slots.

[0099] Time sharing of RF and baseband processing resources is facilitated by the TDD protocol, which is typically used in wireless systems operating above 3 GHz.

[0100] For example, during a downlink time slot, RF switch 600 can be switched to reconfigurable reflector 102, allowing channel estimation to be performed between reconfigurable reflector 102 and another remote transceiver. This operation can be easily performed because during a downlink transmission time slot, RF receiver 601, analog-to-digital converter 602, and baseband processing unit 603 are not used to process radio signals transmitted by mobile user equipment.

[0101] Conversely, during uplink time slots, the sharing of RF receiver 601, analog-to-digital converter 602, and baseband processing unit 603 can be achieved by defining specific receive slots using the scheduling function of remote transceiver 100. For example, through the scheduling function, some uplink time slots can be freed uplink data traffic and used to estimate channels between the reconfigurable reflector 102 and one or more mobile user equipments (MAGs) served by another remote transceiver. In these empty uplink time slots, RF switch 600 can be switched to the reconfigurable reflector 102, allowing channel estimation to be performed. Conversely, in other uplink time slots, switch 600 can be switched to antenna 101. Note that this process requires a degree of coordination or centralization of the scheduling functions of a group of adjacent remote transceivers connected to the same central unit.

[0102] The remote transceiver 100 can be used in several scenarios to improve the performance of mobile communication networks.

[0103] Figure 7 A first exemplary scenario using the remote transceiver 100 is illustrated schematically.

[0104] In this scenario, a portion of the mobile communication network 1000 includes remote transceiver 100 and another remote transceiver 200. As a non-limiting example, remote transceivers 100 and 200 can be remote unit RUs as defined by 3GPP (3rd Generation Partnership Project) and the O-RAN (Open RAN) Alliance. Remote transceivers 100 and 200 can be parts of the same base station. In this case, they are both connected to the same central unit via corresponding links (…). Figure 7 (Not shown in the image). Otherwise, remote transceivers 100 and 200 may be parts of different base stations. In this case, each remote transceiver 100 and 200 is connected to the central unit of the respective base station via a corresponding link.

[0105] The remote transceiver 100 is as described above, and accordingly includes a reconfigurable reflective surface 102. To avoid overburdening the figures, Figure 7The antenna 101 and link 104 of the remote transceiver are not shown. The antenna 101 allows the remote transceiver 100 to exchange user data with one or more mobile user equipment (including mobile user equipment 11) located in its coverage area 100a, as schematically indicated by arrow A3. The remote transceiver 100 is fixed to a physical support, such as a lamppost 100b.

[0106] The remote transceiver 200 can be a known remote transceiver (i.e., it may not include any reconfigurable reflective surface), or it can be according to the invention, and therefore can include a reconfigurable reflective surface. In either case, it includes an antenna (not shown) that allows the remote transceiver 200 to exchange user data with one or more mobile user equipments (including mobile user equipment 21, 22) located in coverage area 200a. Coverage area 200a is adjacent to coverage area 100a. The remote transceiver 200 is fixed to a physical support, such as a lamppost 200b.

[0107] Although the mobile user equipment 21 and the remote transceiver 200 are within line of sight (see...) Figure 7 (As indicated by arrow A1 in the diagram), but a large obstacle 3 (e.g., a group of buildings) obstructs the propagation of radio signals within the line of sight between mobile user equipment 22 and remote transceiver 200. Mobile user equipment 22 is alternatively within the line of sight of remote transceiver 100, particularly with its reconfigurable reflective surface 102.

[0108] Therefore, in order to improve the transmission characteristics of the radio channel between the remote transceiver 200 and the mobile user equipment 22, the reconfigurable reflective surface 102 of the remote transceiver 100 can be configured to guide the radio signals between the remote transceiver 200 and the mobile user equipment 22, such as... Figure 7 Arrow A2' in the diagram schematically indicates that beamforming techniques can be applied to the antenna of the transceiver 200 to provide a radiation pattern in which its main lobe is guided by the reconfigurable reflective surface 102. In this way, when the radiation pattern of the reconfigurable reflective surface 102 (and therefore its reflection angle) is properly adjusted, its guiding effect substantially ensures radio coverage in all areas of coverage area 200a, including blind spots behind the obstacle 3 where the mobile user equipment 22 is located.

[0109] If the radiation pattern of the antenna of the remote transceiver 200 can be configured to provide two main lobes, then each main lobe can be directed to the reconfigurable reflective surface of the corresponding remote transceiver adjacent to the remote transceiver 200.

[0110] For example, Figure 8A portion of a mobile communication network 1000' comprising three remote transceivers 100, 200, and 300 is shown. Each remote transceiver 100, 200, and 300 is fixed to a corresponding physical support, such as lampposts 100b, 200b, and 300b.

[0111] The remote transceiver 200 has a coverage area 200a where the mobile user equipment 22 and 23 are located. The radiation pattern of the antenna of the remote transceiver 200 presents two main lobes L1 and L2.

[0112] Remote transceivers 100 and 300 have corresponding coverage areas adjacent to coverage area 200a. Figure 8 (Not shown in the image). The remote transceivers 100 and 300 are according to embodiments of the present invention and are correspondingly provided with corresponding reconfigurable reflective surfaces 102 and 302.

[0113] Large obstacles 3 (e.g., a group of buildings) obstruct the propagation of radio signals within the line of sight between mobile user equipment 22, 23 and remote transceiver 200. Mobile user equipment 22, 23 are alternatively within the line of sight of remote transceivers 100, 300, particularly with their reconfigurable reflective surfaces 102, 302.

[0114] Therefore, in order to improve the transmission characteristics of the radio channel between the remote transceiver 200 and the mobile user equipment 22, 23, each of the two lobes L1, L2 is preferably guided to a corresponding reconfigurable reflective surface 102, 302, such as Figure 8 Arrows A2'' and A2''' are schematically indicated in the diagram. In this way, when the radiation pattern (and therefore its reflection angle) of the reconfigurable reflective surfaces 102, 302 is properly adjusted, the channel characteristics between the remote transceiver 200 and the mobile user equipment 22, 23 are advantageously optimized.

[0115] It can be recognized that, Figure 7 and Figure 8 This scenario allows for similar improvements in the energy efficiency of mobile communication networks. For example, during certain periods (e.g., at night), the active portion of the remote transceiver 200 can be turned off, and (as an example reference) Figure 8 (In this scenario) the reconfigurable reflective surfaces 102 and 302 can be configured to reflect radio signals from adjacent remote transceivers, thereby partially guaranteeing radio coverage of the coverage area 200a. In this way, the power consumption of the mobile communication network 1000' can be reduced.

[0116] Multi-carrier scenarios can also be envisioned.

[0117] Mobile communication networks can indeed support transmission on N different carrier frequencies. This can happen in mobile communication networks operating, for example, in the millimeter-wave band or the Asia-Pacific Hertz band. In this case, each remote transceiver can typically only operate on a subset of N carrier frequencies. Furthermore, remote transceivers providing radio coverage for adjacent areas often operate on different carrier frequencies.

[0118] In this scenario, the reconfigurable reflective surface 102 can be configured to operate on one or more carrier frequencies that are different from one or more carrier frequencies used by the antenna 101 of the same remote transceiver 100.

[0119] For example, Figure 9 A portion of a mobile communication network 1000'' using three carrier frequencies f1, f2, f3 and comprising three remote transceivers 100, 200, 300 is shown. Each remote transceiver 100, 200, 300 provides radio coverage to a corresponding coverage area 100a, 200a, 300a using the corresponding carrier frequency f1, f2, f3. Coverage areas 100a, 200a, 300a are adjacent, as might happen, for example, when they are substantially hexagonal.

[0120] All remote transceivers 100, 200, 300 are preferably based on embodiments of the invention and accordingly include correspondingly reconfigurable reflective surfaces 102, 202, 302. Each surface 102, 202, 302 is preferably configured to operate at the following carrier frequencies:

[0121] - Surface 102: Carrier frequencies f2 and f3;

[0122] - Surface 202: Carrier frequencies f1 and f3; and

[0123] - Surface 302: Carrier frequencies f1 and f2.

[0124] In this way, the reconfigurable reflective surface 202 or 302 can be used to reflect radio signals having a carrier frequency f1 transmitted or received by the antenna of the remote transceiver 100; the reconfigurable reflective surface 102 or 302 can be used to reflect radio signals having a carrier frequency f2 transmitted or received by the antenna of the remote transceiver 200; and the reconfigurable reflective surface 102 or 202 can be used to reflect radio signals having a carrier frequency f3 transmitted or received by the antenna of the remote transceiver 300. Figure 9An exemplary scenario is shown in which a reconfigurable reflective surface 102 reflects a radio signal having a carrier frequency f2 transmitted and received by the antenna of the remote transceiver 200, thereby providing radio coverage at carrier frequency f2 for mobile user equipment 11 located in coverage area 100a.

[0125] In order to operate on multiple carrier frequencies, each reconfigurable reflective surface 102, 202, 302 is preferably partitioned.

[0126] More generally, if the reconfigurable reflective surface is to support K carrier frequencies, then it is preferably partitioned into K segments, where K ≥ 2. Each segment is preferably configured to operate at the corresponding carrier frequency. Alternatively, the reconfigurable reflective surface can be temporally partitioned, meaning that different time slots are provided, and each time slot is dedicated to reflecting the corresponding carrier frequency.

Claims

1. A remote transceiver (100) for a mobile communication network, the remote transceiver (100) comprising: - Antenna (101); - A reconfigurable reflective surface (102) comprising an array of conductive elements arranged on a two-dimensional substrate; as well as - The data processing unit (103) is configured to direct user data (D1) addressed to at least one mobile user equipment (11) located in the coverage area (100a) of the remote transceiver (100) to the antenna (101) and to direct configuration data (D2) for adjusting the radiation pattern of the reconfigurable reflective surface (102) to the reconfigurable reflective surface (102). The antenna (101) is configured to transmit user data (D1) to at least one mobile user equipment (11) located in the coverage area (100a) of the remote transceiver (100); and The reconfigurable reflective surface (102) is configured to reflect radio signals carrying additional user data exchanged by another remote transceiver (200) with at least one additional mobile user equipment (22) located in another coverage area (200a) of the other remote transceiver (200) according to a radiation pattern adjusted based on configuration data (D2).

2. The remote transceiver (100) according to claim 1, wherein user data (D1) and configuration data (D2) are received in packets by a data processing unit (103) from a link (104), the link (104) connecting the remote transceiver (100) to a central unit of a base station of a mobile communication network, each packet including at least one field indicating the type of data carried by the packet, and wherein the data processing unit (103) includes a demultiplexer (1034) configured to determine whether the packet contains user data (D1) or configuration data (D2) based on the value of the at least one field.

3. The remote transceiver (100) according to claim 1 or 2, wherein the configuration data (D2) includes a vector of reflection coefficients, each reflection coefficient indicating an adjustable phase shift introduced by a corresponding conductive element of the reconfigurable reflective surface (102).

4. The remote transceiver (100) according to claim 3, wherein at least one of the reflection coefficients has an amplitude greater than 1.

5. The remote transceiver (100) according to any one of the preceding claims, wherein the data processing unit (103) is configured to locally generate further configuration data for further adjusting the radiation pattern of the reconfigurable reflective surface (102) and direct the further configuration data to the reconfigurable reflective surface (102).

6. The remote transceiver (100) according to any one of the preceding claims, wherein the antenna (101) and the reconfigurable reflective surface (102) are arranged on the surface of the housing (107) of the remote transceiver (100).

7. The transceiver (100) according to any one of the preceding claims, wherein the reconfigurable reflective surface (102) further includes at least one sensing device embedded in a conductive element of the reconfigurable reflective surface (102), and wherein the transceiver (100) further includes a radio frequency switch (600) and a baseband processing unit (603), the radio frequency switch (600) being configured to selectively connect the baseband processing unit (603) to the antenna (101) and the at least one sensing device, the baseband processing unit (603) being configured to perform a channel estimation function on at least one pilot radio signal transmitted by the other transceiver (200) or the at least one additional mobile user equipment (22) located in the other coverage area (200a) of the other transceiver (200) when connected to the at least one sensing device.

8. A mobile communication network (1000) comprising a remote transceiver (100) and another remote transceiver (200), wherein the remote transceiver (100) comprises: - Antenna (101); - A reconfigurable reflective surface (102) comprising an array of conductive elements arranged on a two-dimensional substrate; as well as - The data processing unit (103) is configured to direct user data (D1) addressed to at least one mobile user equipment (11) located in the coverage area (100a) of the remote transceiver (100) to the antenna (101) and to direct configuration data (D2) for adjusting the radiation pattern of the reconfigurable reflective surface (102) to the reconfigurable reflective surface (102). The antenna (101) is configured to transmit user data (D1) to at least one mobile user equipment (11) located in the coverage area (100a) of the remote transceiver (100); and The reconfigurable reflective surface (102) is configured to reflect radio signals carrying additional user data exchanged by the other transceiver (200) with at least one additional mobile user equipment (22) located in another coverage area (200a) of the other transceiver (200) according to a radiation pattern adjusted based on configuration data (D2).

9. The mobile communication network (1000) according to claim 8, wherein the remote transceiver (100) and the other remote transceiver (200) operate at a first carrier frequency f1 and a second carrier frequency f2, respectively, the first carrier frequency f1 and the second carrier frequency f2 being higher than 5 GHz.

10. The mobile communication network (1000) according to claim 9, wherein the first carrier frequency f1 is different from the second carrier frequency f2.

Images