System and design method for antenna filter unit (AFU) of massive MIMO radio unit

Abstract

The present disclosure relates to an antenna filter unit (280) communicatively coupled to a radio frequency (RF) front-end module (RFEM) (250). The AFU (280) includes a multiple-input multiple-output (MIMO) antenna unit and multiple cavity filters that enable beamforming to multiple users.

Description

[Technical field]

[0001] The present disclosure relates generally to network devices, and more particularly to the design and architecture of an antenna filter unit (AFU) for a massive multiple-input multiple-output (MIMO) radio unit. [Background technology]

[0002] The following description of related art is intended to provide background information regarding the field of the disclosure. This section may include certain aspects of the art that may be related to various features of the present disclosure. However, it should be understood that this section is not intended as an admission of prior art, but is merely intended to enhance the reader's understanding of the present disclosure.

[0003] 5G communication systems are expected to be realized in sub-6 GHz and higher frequency (millimeter (mm) wave) bands, for example, 60 gigahertz (GHz) band, to achieve higher data rates. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, fully dimensional MIMO (FD-MIMO), array antennas, analog beamforming and large-scale antenna technologies are being considered for use in 5G communication systems.

[0004] Conventional antenna filter units are not capable of handling multi-pass bands and various stop bands. It is difficult to find an optimal balance of radio frequency (RF) components that utilize high performance capacity with a uniquely wide operating bandwidth. Furthermore, conventional antenna filter units are bulky and require high power to operate. Conventionally, cable assemblies are used for signal transmission in conventional antenna filters. However, the quality and performance requirements associated with cable assemblies are also very high and require larger space to operate.

[0005] Therefore, there is a need in the art to provide a system and method that can alleviate problems associated with the prior art. Summary of the Invention

[0006] In one aspect, the present disclosure relates to an antenna filter unit (AFU) operatively coupled to a radio frequency front-end module (RFEM), which may include multiple cavity filters and multiple-input multiple-output (MIMO) antenna units to enable beamforming to multiple users.

[0007] In an embodiment, the AFU may further include a calibration printed circuit board (PCB).

[0008] In an embodiment, the AFU may be blind-mated with the RFEM.

[0009] In an embodiment, the AFU and RFEM may be configured on a high speed transceiver board (HSTB) with a transmission line connected between the two connectors as a pole.

[0010] In an embodiment, the AFU includes one or more antenna ports as receiver and transmitter outputs, and the one or more antenna ports may be connected to respective cavity filters to achieve a 32T32R configuration that provides a steeper roll-off outside the operating band.

[0011] In an embodiment, the HSTB may include multiple transceivers. Digital signals received from a Combined Central and Distributed Unit (CCDU) ​​may be converted to RF signals and processed to analog signals using one or more converters for transmission to the RFEM.

[0012] In an embodiment, the RFEM may include multiple RF switches and one or more low noise amplifiers (LNAs) for transmit and receive chains to process received analog signals and send output signals to the AFU.

[0013] In an embodiment, the HSTB may be disposed in a metal housing having a covering on a bottom side, and the AFU may be configured to be coupled to the metal housing from the bottom side, and the metal housing may be an aluminum metal housing.

[0014] In one aspect, the present disclosure relates to a user equipment communicatively coupled to a MIMO radio unit. The user equipment may include one or more primary processors communicatively coupled to one or more processors of the MIMO radio unit via a network, the one or more primary processors coupled to a memory, the memory storing instructions that, when executed by the one or more primary processors, cause the MIMO radio unit to transmit one or more radio frequency (RF) control signals to a UE, an antenna filter unit (AFU) communicatively coupled to the MIMO radio unit and configured with a MIMO antenna unit and multiple cavity filters to enable beamforming to multiple users, the AFU communicatively coupled to a radio frequency front-end module (RFEM) in the MIMO radio unit.

[0015] In one aspect, the present disclosure relates to a non-transitory computer-readable medium including processor-executable instructions that cause the processor to transmit one or more RF control signals to a MIMO radio unit, an antenna filter unit (AFU) communicatively coupled to the MIMO radio unit and configured with a MIMO antenna unit and multiple cavity filters that enable beamforming to multiple users, and the AFU communicatively coupled to a radio frequency front-end module (RFEM) in the MIMO radio unit. [Problem to be solved by the invention]

[0016] An object of the present invention is to provide higher spectral efficiency by enabling its antenna array to focus a narrow beam onto a user.

[0017] It is an object of the present invention to provide a more energy efficient system in which the antenna array is focused to a small specific section, which requires less radiated power, lowering the energy requirements in massive MIMO systems.

[0018] SUMMARY OF THE PRESENT EMBODIMENT It is an object of the present invention to increase the data rate and capacity of wireless systems.

[0019] It is an object of the present invention to facilitate more reliable and accurate user tracking.

[0020] The object of the present invention is to eliminate high power consumption.

[0021] An object of the present invention is to reduce delays and improve network reliability.

[0022] The object of the present invention is to provide a cableless design of a Massive MIMO radio unit.

[0023] The objective of the present invention is to provide a massive MIMO standalone unit located in a single convection cooled enclosure and weighing less than 25-29 kg.

[0024] The objective of the present invention is to provide a Massive MIMO standalone unit consisting of a lower layer PHY section, an ORAN compliant fronthaul over a 25G optical interface, and digital front-end support for 32 transmit and receive chains utilizing three commercial grade FPGAs.

[0025] The objective of the present invention is to provide a Massive MIMO standalone unit that includes an integrated 8x8 MIMO antenna with 32 cavity filters in one unit known as an Antenna Filter Unit (AFU). [Brief description of the drawings]

[0026] The accompanying drawings, which are incorporated herein and form a part of the present invention, illustrate exemplary embodiments of the disclosed method and system, with like reference numerals referring to the same parts throughout the different drawings. The components in the drawings are not necessarily drawn to scale, emphasis instead being placed on clearly illustrating the principles of the invention. Some figures may use block diagrams to illustrate components and may not show the internal circuitry of each component. Those skilled in the art will appreciate that the inventions in such drawings include inventions in electrical or electronic components or circuits commonly used to implement such components.

[0027] [Figure 1] 1 illustrates an exemplary design architecture of a massive MIMO radio unit according to an embodiment of the present disclosure. [Diagram 2] 1 illustrates an example design architecture of an antenna filter unit (AFU) in accordance with an aspect of the present disclosure. [Diagram 3] 1 illustrates an example combined representation of a user equipment (UE) with a MIMO radio unit according to an aspect of the present disclosure. [Figure 4] 1 illustrates an exemplary computer system in which embodiments of the present invention may be utilized, according to embodiments of the present disclosure.

[0028] The above will become more apparent from the following more detailed description of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] In the following description, for purposes of explanation, various specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it will be apparent that the embodiments of the present disclosure may be practiced without these specific details. Some features described below may be used independently of each other or in any combination with other features. Individual features may not address all of the above problems, or may address only some of the above problems. Some of the above problems may not be fully addressed by any of the features described herein.

[0030] The following description provides exemplary embodiments only and is not intended to limit the scope, applicability, or configuration of the present disclosure. Rather, the following description of exemplary embodiments provides those skilled in the art with an effective description for implementing the exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the spirit and scope of the invention as described.

[0031] Specific details are provided below to provide a thorough understanding of the embodiments. However, it will be understood by those skilled in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, networks, processes, and other components may be shown as components in block diagrams so as not to obscure the embodiments with unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail so as to avoid obscuring the embodiments.

[0032] It should also be noted that the particular embodiments may be described as a process that is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations may be performed in parallel or simultaneously. Moreover, the order of operations may be rearranged. A process terminates when the operation is completed, but may have additional steps not included in the diagram. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination may correspond to a return of the function to the calling function or to the main function.

[0033] The terms "exemplary" and / or "illustrative" are used herein to mean serving as an example, instance, or illustration. For the avoidance of doubt, the subject matter disclosed herein is not limited by such examples. Further, any aspect or design described herein as "exemplary" and / or "illustrative" is not necessarily to be construed as preferred or advantageous over other aspects or designs, and is not intended to exclude equivalent exemplary structures and techniques known to those skilled in the art. Furthermore, to the extent that "includes," "has," "contains," and other similar terms are used in the detailed description or claims, such terms are intended to be inclusive in the same manner as the term "comprising" as an open transition term, without excluding any additional or other elements.

[0034] References throughout this specification to "one embodiment," "an embodiment," "an example," or "one example" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0035] The terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting of the present invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It will be further understood that the term "comprises" / (comprising) as used herein indicates the presence of stated features, integers, steps, processes, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, processes, elements, components and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0036] In the present disclosure, various embodiments are described using terms used in some communication standards (e.g., 3GPP (3rd Generation Partnership Project), xRAN (extensible Radio Access Network), and O-RAN (open radio access network)), which are merely illustrative examples. Various embodiments of the present disclosure may also be easily modified and applied to other communication systems.

[0037] Typically, a base station is a network infrastructure that provides wireless access to one or more terminals. A base station has a coverage that is defined to be a given geographic area based on the distance over which signals can be transmitted. In addition to "base station," a base station may be referred to as an "access point (AP)," "evolved Node B (eNodeB) (eNB)," "5G node (fifth generation node)," "next generation Node B (gNB)," "wireless point," "transmit / receive point (TRP)," or other term having an equivalent technical meaning.

[0038] The present disclosure relates to an Open Radio Access Network (O-RAN) compliant 5G Massive MIMO Radio Unit (MRU) (hereinafter alternatively and interchangeably referred to as "5G MRU" or "RU"). In an exemplary and non-limiting example, the present disclosure provides a hardware architecture and design of a 5G Massive MIMO (MRU) based on multiple antenna configuration 32T32R (32 transmitters and 32 receivers) for standalone mode in an exemplary embodiment, where the proposed 5G MRU is a Radio Unit (RU) connected to a Combined Central and Distributed Unit (CCDU) ​​over a fronthaul interface using a 25G optical interface and conforms to the 3GPP (Third Generation Partnership Project) based Open Radio Access Network (ORAN) specification. The proposed MRU, in an exemplary embodiment, has three cell sites and three corresponding MRUs used with the CCDU, and each MRU is configurable to be connected to the CCDU via the 25G interface.

[0039] In an exemplary embodiment, the proposed 5G MRU comprises a lower PHY (physical) portion of the L1 layer with a network layer split of 7.2X (O-RAN Alliance Fronthaul Specification between O-DU and O-RRU), a baseband section, an RF (radio frequency) front-end module (RFEM), and an antenna filter unit (AFU) as part of a single enclosure / unit for easy and efficient installation. However, it should be understood that the design and architecture of each of the components / units of the proposed RU is novel and inventive as far as this disclosure is concerned, and therefore each component and its configuration / structure are protected through respective / separate patent applications.

[0040] In an exemplary aspect, with reference to FIG. 1, the proposed 5G MRU 100 may include a High Speed ​​Transceiver Board (HSTB) 200 having a lower layer physical section, an ORAN compliant fronthaul on a 25G optical interface 204, and a digital RF front-end support module (RFEM) having transmit and receive chains (in an exemplary example, 32 chains) using, for example, three commercial grade FPGAs / transceivers (202-1 to 202-3, hereinafter collectively referred to as 202), which are integrated onto a high density multi-layer configuration (e.g., in an embodiment, 26 layers) of the HSTB 200. Although the present disclosure is described in terms of a Field Programmable Gate Array (FPGA), any other equivalent transceiver is within the full scope of the present disclosure, and thus the scope of each FPGA should be treated as the scope of any transceiver or technically equivalent component such as an Application-Specific Integrated Circuit (ASIC).

[0041] In an exemplary aspect, the L1 lower layer PHY deployment and bitstream generation can be realized / implemented in the FPGA 202 itself. The L1 upper layer can be configured on a CCDU (Communication and Capacity Development Unit) below the tower, L2 and L3 can be configured on a DU (Distributed Unit), and the macro site typically includes a central unit node (server side) and a distributed unit node (configured between a CU (Central Unit) and a RU (Radio Unit)). The present disclosure merges the central unit node and the distributed unit node to form a CCDU that interfaces with the RU / MRU via a 25G optical interface as proposed in the present disclosure. Furthermore, the proposed MRU can include an IEEE 1588 v2 PTP-based clock synchronization architecture on the 25G optical interface 204 utilizing a system synchronizer IC and a clock generator.

[0042] The proposed MRU 100 may further include an integrated 8×8 MIMO antenna with 32 cavity filters as one unit known as an antenna filter unit (AFU) 280. As configured, the proposed MRU 100 may be blind-mated and have a cableless design.

[0043] In an exemplary, non-limiting aspect of the present disclosure, the proposed 5G MRU 100 is a 200W high power gNB operating in the macro class (typically 6.25W or 38dBm per antenna port) and configured to provide a macro level wide area measure for coverage and capacity that can find utility in high density urban morphology and hot zone / hot spot areas with high traffic and QoS requirements. The proposed 5G MRU 100 can put together a commercial grade FPGA based lower layer physical section and RF transceiver (as part of the HSTB 200) for 32 transmit and receive chains. The MRU 100 can further include an RF front end module (RFEM) 250 that can include multiple RF power amplifiers, low noise amplifiers (LNAs) and RF switches for the 32 chains. The MRU can further include multiple 8x8 MIMO antennas with multiple cavity filters (e.g., 32 filters) known as antenna filter units (AFUs) 280 as part of a single convection cooled enclosure, weighing less than 25kg. In one aspect, the macro gNB can provide good coverage and capacity for dense urban clutter due to the support of 8 beams in downlink and 4 beams in uplink under multi-UE scenario. The proposed 5G MRU 100 can be deployed in hotspot locations where high-rise buildings, dense clutter and traffic demands are significantly high and cannot be provided by 4G gNB alone for coverage and capacity augmentation.

[0044] In another aspect, the proposed 5G MRU can be configured as a design with integrated antenna and cavity filter means, making it a cable-less design, without the need for the use of cables. The proposed MRU 100 can be deployed at tower sites, GBTs and GBMs. The MRU can be rapidly deployed to provide high performance with low power consumption, making the MRU a power efficient means. The proposed MRU can be connected to the CCDU down the tower over a single 25G optical fronthaul interface compliant with 3GPP ORAN.

[0045] In one aspect, the proposed 5G MRU is a high power Next Generation Node B (gNB) operating at macro class (typically 38 dBm or less per antenna port) and can be configured to complement macro level wide area measures for coverage and capacity. In an exemplary aspect, the high level architecture of the proposed 32T32R 5G NR MRU can include a High Speed ​​Transceiver Board (HSTB) 200, a 32T32R RF Front End Module (RFEM) board 250, an Antenna Filter Unit (AFU) 280, and a mechanical housing (in one example, there can be two housings, one for the HSTB 200 and one for the RFEM 250). The proposed MRU structure further provides and enables optimal heat dissipation for operation in weather conditions ranging from -10°C to 50°C.

[0046] In an exemplary aspect, the proposed 5G NR MRU 100 includes a lower layer physical section, a commercial grade FPGA-based RF transceiver (as part of the HSTB 200) for 32 transmit and receive chains with RF sampling (no intermediate frequency stage), an RF front-end module (RFEM) 250 including RF power amplifiers, low noise amplifiers (LNAs), RF switches for the 32 chains, and an 8×8 MIMO antenna together with 32 cavity filters in a single convection-cooled enclosure known as the antenna filter unit (AFU) 350 and weighing under 29 kg.

[0047] In an exemplary embodiment, the proposed MRU 100 has 64 connectors, 32 each on the transmit and receive side, and two DC connectors, each with 25 pins, for a total of 50 pins for the two DC connectors. These connectors are configured on the HSTB 200 to blind connect / map / mate / sandwich with the RFEM board 250, one on top of the other.

[0048] In one aspect, the proposed design architecture comprises a control plane, a user plane and a synchronization plane, where the control plane is configured to control the configuration of the units / subunits forming part of the proposed MRU 100 from a remote perspective, the user plane consists of user data and finally the synchronization plane is configured to utilise Precision Time-based Protocol (PTP) over the 25G interface to synchronise the units / subunits with respect to a global clock using a timing protocol (i.e. a slave device will synchronise its clock with the master device in phase and frequency) and maintain consistency / synchronisation with the CCDU.

[0049] It will be seen that the proposed MRU meets all RF performance requirements after integrating a TDD-based 5G NR MRU5 with a CFR (Crest Factor Reduction) and DPD (Digital Pre-Distortion) module in the digital front-end lineup. Furthermore, the MRU has low power consumption and is thermally optimally handled by an IP65 ingress protected mechanical housing.

[0050] Antenna Filter Unit (AFU) 280 FIG. 2 illustrates an example design architecture of an antenna filter unit (AFU) according to an embodiment of the present disclosure.

[0051] In an exemplary aspect, the proposed AFU comprises an 8x8 MIMO (128 single antenna elements) antenna unit with a calibration PCB and a cavity filter in one integrated unit known as the AFU, configured to blind-mate with the RFEB and enable beamforming to multi-user MIMO. The AFU can be configured to be coupled to the housing from below in an exemplary embodiment / design, and the board is placed in an aluminum metal housing with a cover on the bottom side. In one aspect, the AFU and RFEB are configured on the HSTB along a cylindrical transmission line from both sides connected between two connectors similar to a pole, such that there are two receptacles between which a pillar is configured to connect these units / subunits.

[0052] The proposed AFU can include a 32-port (32 antenna ports transmitted as receivers arrive at the same antenna port, and the 32 ports are connected to corresponding / respective 32 cavity filters) cavity filter for a 32T3R configuration that provides a steeper roll-off outside the operating band. The proposed AFU allows for a unique radiation pattern, low loss, and low interference.

[0053] In one aspect, the proposed MRU, due to the design and deployment of the MRU architecture and the reduced loss and cable count, can achieve a system noise figure of 3.5-3.6 dB, enabling blind mating.

[0054] FIG. 3 illustrates an exemplary coupling representation of an MRU and a user equipment. As illustrated, a UE 302 may be communicatively coupled to the MRU 100. This coupling may occur via a wireless network 304. In an exemplary embodiment, the communication network 304 may include at least a portion of one or more networks having one or more nodes that transmit, receive, forward, generate, buffer, store, route, switch, process, or any combination thereof, such as, for example and without limitation, one or more messages, packets, signals, waves, voltage or current levels, any combination thereof, or the like. The UE 302 may be any portable device, mobile device, palmtop, laptop, smartphone, pager, or the like. As a result of the coupling, the UE 302 may be configured to receive a connection request from the MRU 100, transmit an acknowledgement of the connection request to the MRU 100, and further transmit a number of signals in response to the connection request.

[0055] Exemplary Computer System 400 FIG. 4 illustrates an exemplary computer system in which embodiments of the present disclosure can be utilized in accordance with embodiments of the present disclosure. As illustrated in FIG. 4, computer system 400 can include an external storage device 410, a bus 420, a main memory 430, a read-only memory 440, a mass storage device 450, a communication port 460, and a processor 470. Those skilled in the art will appreciate that a computer system may include more than one processor and communication port. Processor 470 includes various modules related to embodiments of the present invention. Communication port 460 can be an RS-232 port for use with a modem-based dial-up connection, a 10 / 100 Ethernet port, a gigabit or 10 gigabit port using copper or fiber, a serial port, a parallel port, or any other existing or future port. Communication port 460 can be selected depending on the network, such as a local area network (LAN), a wide area network (WAN), or any network to which the computer system is connected. Memory 430 may be a random access memory (RAM) or any other dynamic storage device commonly known in the art. Read-only memory 440 may be any static memory device. Mass storage 450 may be any present or future mass storage means available for storing information and / or instructions.

[0056] The bus 420 communicatively couples the processor 470 with other memory, storage and communication blocks.

[0057] Optionally, operator and management interfaces, such as a display, keyboard, and cursor control devices, may also be coupled to bus 420 to support direct operator interaction with the computer system. Other operator and management interfaces may be provided through a network connection connected through communications port 460. The components described above are intended only to illustrate various possibilities. The exemplary computer system described above is not intended to limit the scope of the present disclosure.

[0058] Although considerable emphasis has been placed herein on the preferred embodiment, it will be understood that numerous embodiments are possible and numerous changes can be made in the preferred embodiment without departing from the principles of the invention. These and other modifications in the preferred embodiment of the invention will be apparent to those skilled in the art from the disclosure herein, and it should thereby be clearly understood that the foregoing description is to be taken merely as illustrative of the invention and not as a limitation thereof.

[0059] Portions of the disclosure of this patent document contain material that is subject to intellectual property rights, including, without limitation, copyright, designs, trademarks, IC layout designs and / or trade dress protection belonging to JPL (Jio Platforms Limited) or its affiliates (hereinafter referred to as the Owner). The Owner has no objection to the facsimile reproduction of any of the patent documents or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all rights. All rights to such intellectual property are fully reserved by the Owner.

[0060] Effect of the Invention The present disclosure provides greater spectral efficiency by enabling its antenna arrays to focus a narrow beam towards a user.

[0061] The present disclosure provides a more energy efficient system when the antenna array is focused to a small specific section, which requires less radiated power, reducing the energy requirements in massive MIMO systems.

[0062] The present disclosure improves data rates and capacity of wireless systems.

[0063] The present disclosure provides more reliable and accurate user tracking.

[0064] The present disclosure eliminates high power consumption.

[0065] The present disclosure reduces delays and improves network reliability.

[0066] The present disclosure provides a cableless design for a massive MIMO radio unit.

[0067] The present disclosure provides a massive MIMO standalone unit located in a single convection cooled enclosure and weighing less than 25-29 kg.

[0068] This disclosure provides the lower layer PHY section, ORAN compliant fronthaul over a 25G optical interface, and digital front-end support for 32 transmit and receive chains utilizing three commercial-grade FPGAs.

[0069] The present disclosure provides a massive MIMO standalone unit that includes an integrated 8×8 MIMO antenna with 32 cavity filters in one unit known as an antenna filter unit (AFU).

Claims

1. An antenna filter unit (AFU) (280), An AFU (280) having a plurality of cavity filters and a multiple-input multiple-output (MIMO) antenna unit that enables beamforming to a plurality of users, the AFU (280) being communicatively coupled to a radio frequency front-end module (RFEM) (250).

2. The AFU of claim 1 , wherein the AFU (280) includes a calibration printed circuit board (PCB).

3. The AFU of claim 1 , wherein the AFU (280) is blind-mated with the RFEM (250).

4. 2. The AFU of claim 1, wherein the AFU (280) and the RFEM (250) are configured on a high speed transceiver board (HSTB) (200) with a transmission line connected between two connectors as a pole.

5. 2. The AFU of claim 1, wherein the AFU includes one or more antenna ports as receiver and transmitter outputs, the one or more antenna ports being connected to respective cavity filters to achieve a 32T32R configuration that provides a steeper roll-off outside the operating band.

6. 5. The AFU of claim 4, wherein the HSTB (200) includes multiple transceivers, and digital signals received from a Combined Central and Distributed Unit (CCDU) ​​are converted to radio frequency (RF) signals and processed to analog signals using one or more converters for transmission to the RFEM (250).

7. 7. The AFU of claim 6, wherein the RFEM (250) includes multiple RF switches and one or more low noise amplifiers (LNAs) for transmit and receive chains to process the received analog signals and send output signals to the AFU (280).

8. 5. The AFU of claim 4, wherein the HSTB (200) is disposed in a metal housing having a covering on a bottom side, and the AFU (280) is configured to be coupled to the metal housing from the bottom side, the metal housing being an aluminum metal housing.

9. A user equipment (UE) (302) communicatively coupled to a multiple-input multiple-output (MIMO) wireless unit (100), comprising: one or more primary processors communicatively coupled to one or more processors of the MIMO wireless unit (100) via a network (304), the one or more primary processors coupled to a memory, the memory storing instructions that, when executed by the one or more primary processors, causing the MIMO wireless unit (100) to transmit one or more radio frequency (RF) control signals to the UE (302); A user equipment, comprising: an antenna filter unit (AFU) (280) communicatively coupled to the MIMO radio unit (100) and configured with a MIMO antenna unit and multiple cavity filters enabling beamforming to multiple users, the AFU (280) communicatively coupled to a radio frequency front-end module (RFEM) (250) in the MIMO radio unit (100).

10. A non-transitory computer readable medium containing processor-executable instructions, the instructions comprising: causing a MIMO wireless unit (100) to transmit one or more radio frequency (RF) control signals to a processor; A medium, wherein an antenna filter unit (AFU) (280) is communicatively coupled to the MIMO radio unit (100) and is configured with a MIMO antenna unit and multiple cavity filters that enable beamforming to multiple users, and the AFU (280) is communicatively coupled to a radio frequency front-end module (RFEM) (250) in the MIMO radio unit (100).

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