Wideband Architecture and Multiband Architecture for Multi-User Transmission Using a Lens Antenna

Abstract

Certain aspects of the present disclosure provide techniques and architectures for the use of multi-antenna technologies that may enable wireless communication systems to exploit the spatial domain and support spatial multiplexing, beamforming, and transmit diversity across wide frequency ranges and / or multiple bands to communicate with multiple users.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 62 / 873,552, filed on Jul. 12, 2019, and claims priority to U.S. Application No. 16 / 912,114, filed on Jun. 25, 2020, the contents of which are hereby incorporated by reference in their entirety.

[0002] Aspects of the present disclosure relate to wireless communication, and more particularly, to an architecture that utilizes lens antennas for multi - user transmission.

Background Art

[0003] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcast, etc. These wireless communication systems may employ multiple - access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple - access systems include, among others, the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system, the LTE - Advanced (LTE - A) system, the Code Division Multiple Access (CDMA (R)) system, the Time Division Multiple Access (TDMA) system, the Frequency Division Multiple Access (FDMA) system, the Orthogonal Frequency Division Multiple Access (OFDMA) system, the Single - Carrier Frequency Division Multiple Access (SC - FDMA) system, and the Time Division - Synchronous Code Division Multiple Access (TD - SCDMA) system.

[0004] In some examples, a wireless multi-connectivity communication system may include several base stations (BSs) each capable of simultaneously supporting communication for a plurality of communication devices, sometimes called user equipment (UE). In an LTE network or an LTE-A network, a set of one or more base stations may define an evolved Node B (eNB). In other examples (e.g., in a next-generation network, a New Radio (NR) network, or a 5G network), a wireless multi-connectivity communication system may include several distributed units (DUs) (e.g., edge units (EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs), transmission reception points (TRPs), etc.) communicating with several central units (CUs) (e.g., central nodes (CNs), access node controllers (ANCs), etc.), where a set of one or more DUs communicating with a CU may define an access node (sometimes called, e.g., a BS, 5G NB, next-generation Node B (gNB or g-node B), transmission reception point (TRP), etc.). A BS or DU may communicate with a set of UEs on a downlink channel (e.g., for transmission from the BS or DU to the UE) and on an uplink channel (e.g., for transmission from the UE to the BS or DU).

[0005] These multi-connectivity technologies are adopted in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate at the urban, national, regional, and even global scales. NR (e.g., New Radio or 5G) is an example of an emerging telecommunications standard. NR is a set of extensions to the LTE mobile standard published by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectral efficiency, reducing costs, improving services, utilizing new spectra, and better integrating with other open standards that use OFDMA with cyclic prefix (CP) on the downlink (DL) and uplink (UL). For these purposes, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0006] However, as the demand for mobile broadband access continues to increase, further improvements in NR technology and LTE technology are needed. Preferably, these improvements should be applicable to other multi-connectivity technologies and the telecommunications standards that adopt these technologies.

SUMMARY OF THE INVENTION

MEANS FOR SOLVING THE PROBLEM

[0007] The systems, methods, and devices of the present disclosure each have several aspects, and only a single one of those aspects does not necessarily carry its desirable attributes. Without limiting the scope of the present disclosure as expressed by the following claims, some features are briefly described herein. After considering this description and especially after reading the section entitled "DETAILED DESCRIPTION OF THE INVENTION," it will be understood how the features of the present disclosure bring about advantages including improved communication between access points and stations in a wireless network.

[0008] Some aspects of the present disclosure relate to an apparatus for wireless communication. The apparatus generally includes N sets of radio frequency (RF) chains, where each RF chain of a given set is configured to generate or process RF signals for different frequency bands, and N synthesizers, where each synthesizer generates a multi-band signal by synthesizing RF signals for different frequency bands generated by at least two of the RF chains of the corresponding set of the N sets of RF chains and is configured to supply the multi-band signal to a lens antenna for transmission via a first transmission beam.

[0009] Some aspects of the present disclosure relate to an apparatus for wireless communication. The apparatus generally includes a first set of radio frequency (RF) chains, where each RF chain of the first set is configured to generate or process RF signals for different frequency bands, a first synthesizer configured to generate a first multi-band signal by synthesizing RF signals for different frequency bands generated by at least two of the RF chains of the first set and to supply the first multi-band signal to a lens antenna for transmission via a first transmission beam, a second set of radio frequency (RF) chains, where each RF chain of the second set is configured to generate or process RF signals for different frequency bands, and a second synthesizer configured to generate a second multi-band signal by synthesizing RF signals for different frequency bands generated by at least two of the RF chains of the second set and to supply the second multi-band signal to a lens antenna for transmission via a second transmission beam.

[0010] Some aspects also include various means and methods corresponding to the functions of the elements described above.

[0011] To achieve the above and related objectives, one or more aspects comprise the features that are fully described below and particularly pointed out in the claims. The following description and the accompanying drawings detail some exemplary features of one or more aspects. However, these features represent only some of the various ways in which the principles of the various aspects can be employed.

[0012] So that the above-described features of the present disclosure can be understood in detail, a more specific description, briefly summarized above, may be obtained by referring to the aspects shown in the drawings. However, it should be noted that since this description can lead to other equally effective aspects, the accompanying drawings show only some exemplary aspects of the present disclosure and should not be considered as limiting the scope of the present disclosure.

Brief Description of the Drawings

[0013]

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[0014] For ease of understanding, the same reference numbers are used to designate the same elements common to the figures, where possible. It is contemplated that elements disclosed in one aspect may be beneficially utilized in other aspects without specific recitation.

[0015] Aspects of the present disclosure provide apparatus and methods for multi-user transmission schemes that utilize a lens antenna.

[0016] The following description provides examples and is not intended to limit the scope, applicability, or examples set forth in the claims. Changes may be made to the functions and configurations of the elements described without departing from the scope of the disclosure. In various examples, various procedures or components may be omitted, substituted, or added as appropriate. For example, the methods described may be performed in an order different from the order described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects described herein. Further, the scope of the disclosure is intended to cover apparatuses or methods practiced using other structures, functions, or structures and functions in addition to or other than the various aspects of the disclosure described herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the claims. The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" should not necessarily be construed as preferred or advantageous over other aspects.

[0017] The techniques described herein may be used for various wireless communication technologies such as LTE, CDMA®, TDMA, FDMA, OFDMA, SC-FDMA, and other networks. The terms "network" and "system" are often used interchangeably. A CDMA® network may implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband CDMA® (WCDMA®) and other variants of CDMA®. Cdma2000 covers the IS-2000, IS-95, and IS-856 standards. A TDMA network may implement radio technologies such as Global System for Mobile Communications (GSM®). An OFDMA network may implement radio technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE802.11 (Wi-Fi), IEEE802.16 (WiMAX), IEEE802.20, Flash OFDMA, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS).

[0018] New Radio (NR) is an emerging wireless communication technology being developed together with the 5G Technology Forum (5GTF). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM® are described in documents from a group called the "3rd Generation Partnership Project" (3GPP). cdma2000 and UMB are described in documents from a group called the "3rd Generation Partnership Project 2" (3GPP2). The techniques described herein may be used for the wireless networks and radio technologies described above, as well as for other wireless networks and radio technologies. For clarity, aspects may be described herein using terms commonly associated with 3G and / or 4G wireless technologies, but aspects of the present disclosure may be applicable in other generation-based communication systems such as 5G and later, including NR technology.

[0019] New Radio (NR) access (e.g., 5G technology) can support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidths (e.g., 80 MHz or more), millimeter wave (mmW) targeting high carrier frequencies (e.g., 25 GHz or more), massive machine type communication MTC (mMTC) targeting non-backward compatible MTC techniques, and / or mission critical such as ultra-reliable low latency communication (URLLC). These services may include latency requirements and reliability requirements. These services may also have different transmission time intervals (TTIs) to meet their respective quality of service (QoS) requirements. Additionally, these services may coexist within the same subframe.

[0020] Exemplary wireless communication system FIG. 1 shows an exemplary wireless communication network 100 in which aspects of the present disclosure may be implemented. For example, base station 110 may perform operation 400 shown in FIG. 4 to perform wideband multi-user wireless communication via a lens antenna using one of the exemplary architectures shown in FIGS. 8-11.

[0021] Wireless communication network 100 may be, for example, a New Radio (NR) or 5G network.

[0022] As shown in FIG. 1, wireless communication network 100 may include several base stations (BSs) 110 and other network entities. A BS may be a station that communicates with user equipment (UE). Each BS 110 may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" can refer to the coverage area of a Node B (NB) and / or the NB subsystem serving this coverage area, depending on the context in which the term is used. In an NR system, the terms "cell" and next-generation Node B (gNB or g-node B), NR BS, 5G NB, access point (AP), or transmission and reception point (TRP) may be interchangeable. In some examples, a cell may not necessarily be fixed, and the geographic area of a cell may move according to the location of a mobile BS. In some examples, base stations may be interconnected with each other and / or with one or more other base stations or network nodes (not shown) in wireless communication network 100 through various types of backhaul interfaces, such as direct physical connections, wireless connections, virtual networks, using any suitable transport network.

[0023] Generally, any number of wireless networks can be deployed within a given geographical area. Each wireless network may support a particular radio access technology (RAT) and may operate on one or more frequencies. RATs may also be referred to as wireless technologies, air interfaces, etc. Frequencies may also be referred to as carriers, sub - carriers, frequency channels, tones, sub - bands, etc. Each frequency may support a single RAT within a given geographical area to avoid interference between wireless networks of different RATs. In some cases, an NR RAT network or a 5G RAT network may be deployed.

[0024] A BS may provide communication coverage to macro cells, pico cells, femto cells, and / or other types of cells. A macro cell may cover a relatively large geographical area (e.g., several kilometers in radius) and may enable unrestricted access by UEs subscribed to the service. A pico cell may cover a relatively small geographical area and may enable unrestricted access by UEs subscribed to the service. A femto cell may cover a relatively small geographical area (e.g., a home) and may enable restricted access by UEs associated with the femto cell (e.g., UEs within a Closed Subscriber Group (CSG), UEs for users within a home, etc.). A BS for a macro cell may sometimes be called a macro BS. A BS for a pico cell may sometimes be called a pico BS. A BS for a femto cell may sometimes be called a femto BS or a home BS. In the example shown in FIG. 1, BS110a, 110b, and 110c may each be a macro BS for macro cells 102a, 102b, and 102c, respectively. BS110x may be a pico BS for pico cell 102x. BS110y and 110z may each be a femto BS for femto cells 102y and 102z, respectively. A BS may support one or more (e.g., three) cells.

[0025] Wireless communication network 100 may also include relay stations. A relay station is a station that receives the transmission of data and / or other information from an upstream station (e.g., a BS or a UE) and sends the transmission of data and / or other information to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that relays transmissions for other UEs. In the example shown in FIG. 1, relay station 110r can communicate with BS110a and UE120r to facilitate communication between BS110a and UE120r. Relay stations are sometimes called relay BSs, relays, etc.

[0026] Wireless communication network 100 may be a heterogeneous network including different types of BSs, such as macro BSs, pico BSs, femto BSs, relays, etc. These different types of BSs may have different transmission power levels, different coverage areas, and different impacts on interference in wireless communication network 100. For example, a macro BS may have a high transmission power level (e.g., 20 watts), while pico BSs, femto BSs, and relays may have much lower transmission power levels (e.g., 1 watt).

[0027] Wireless communication network 100 may support synchronous operation or asynchronous operation. In the case of synchronous operation, BSs may have similar frame timings, and transmissions from different BSs may be approximately time-aligned. In the case of asynchronous operation, BSs may have different frame timings, and transmissions from different BSs may not be time-aligned. The techniques described in this specification may be used for both synchronous and asynchronous operations.

[0028] Network controller 130 may be coupled to a set of BSs and may perform coordination and control for these BSs. Network controller 130 may communicate with BS110 via a backhaul. BS110s may also communicate with each other (e.g., directly or indirectly) via a wireless backhaul or a wireline backhaul.

[0029] UE 120 (e.g., 120x, 120y, etc.) may be distributed throughout the wireless communication network 100, and each UE may be fixed or mobile. A UE may be a mobile station, a terminal, an access terminal, a subscriber unit, a station, a customer premises equipment (CPE), a cellular phone, a smartphone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, an appliance, a medical device or instrument, a biosensor / biodevice, a smartwatch, smart clothing, smart glasses, a smart list band, wearable devices such as smart jewelry (e.g., a smart ring, a smart bracelet, etc.), entertainment devices (e.g., a music device, a video device, a satellite radio, etc.), vehicle components or vehicle sensors, a smart meter / smart sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless medium or a wired medium. Some UEs may be regarded as machine type communication (MTC) devices or evolved MTC (eMTC) devices. MTC UEs and eMTC UEs may communicate with, for example, a BS, another device (e.g., a remote device), or some other entities, including robots, drones, remote devices, sensors, meters, monitors, location tags, etc. A wireless node may provide connectivity for a network (e.g., a wide area network such as the Internet or a cellular network) or connectivity to the network via, for example, a wired communication link or a wireless communication link. Some UEs may be regarded as Internet of Things (IoT) devices, and the IoT devices may be narrowband IoT (NB-IoT) devices.

[0030] Some wireless networks (e.g., LTE) utilize orthogonal frequency division multiplexing (OFDM) on the downlink and single carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are typically also called tones, bins, etc. Each subcarrier can be modulated with data. Generally, modulation symbols are sent using OFDM in the frequency domain and SC-FDM in the time domain. The spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may depend on the system bandwidth. For example, the subcarrier spacing may be 15 kHz, and the minimum resource allocation (referred to as a "resource block" (RB)) may be 12 subcarriers (i.e., 180 kHz). Thus, the nominal fast Fourier transform (FFT) size may be equal to 128, 256, 512, 1024, or 2048 for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidth may also be divided into subbands. For example, a subband may cover 1.08 MHz (i.e., 6 resource blocks), and there may be 1, 2, 4, 8, or 16 subbands for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0031] Communication systems such as NR may well utilize OFDM with cyclic prefix (CP) on the uplink and downlink, and may include support for half-duplex operation using time-division duplex (TDD). Beamforming may well be supported, and the beam direction may be configured dynamically. MIMO transmission with precoding may also be supported. The MIMO configuration in the DL may support up to eight transmit antennas using multi-layer DL transmission with up to eight streams and up to four streams per UE. Multi-layer transmission with up to four streams per UE may be supported. Aggregation of multiple cells may be supported using up to eight serving cells.

[0032] In some examples, access to the air interface may be scheduled. A scheduling entity (e.g., BS) allocates resources for communication between some or all of the devices and apparatuses within its service area or cell. The scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, the subordinate entity utilizes the resources allocated by the scheduling entity. The base station is not the only entity that may function as a scheduling entity. In some examples, a UE may function as a scheduling entity, may schedule resources for one or more subordinate entities (e.g., one or more other UEs), and the other UEs may utilize the resources scheduled by that UE for wireless communication. In some examples, a UE may function as a scheduling entity within a peer-to-peer (P2P) network and / or within a mesh network. In a mesh network example, the UEs may communicate directly with each other in addition to communicating with the scheduling entity.

[0033] In FIG. 1, the solid line with double arrows indicates the desired transmission between the UE and the serving BS, where the serving BS is the BS designated to serve the UE on the downlink and / or the uplink. The thin dashed line with double arrows indicates the interfering transmission between the UE and the BS.

[0034] FIG. 2 shows exemplary components of BS 110 and UE 120 (as shown in FIG. 1) that may be used to implement aspects of the present disclosure. For example, the antenna 252, processors 266, 258, 264, and / or controller / processor 280 of UE 120, and / or the antenna 234, processors 220, 230, 238, and / or controller / processor 240 of BS 110 may be used to execute the various techniques and methods described herein.

[0035] In BS110, the transmission processor 220 may receive data from the data source 212 and control information from the controller / processor 240. The control information may be for the physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical hybrid ARQ indicator channel (PHICH), physical downlink control channel (PDCCH), group common PDCCH (GC PDCCH), etc. The data may be for the physical downlink shared channel (PDSCH), etc. The processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The processor 220 may also generate reference symbols, for example, for the primary synchronization signal (PSS), secondary synchronization signal (SSS), and cell-specific reference signal (CRS). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, control symbols, and / or reference symbols, if applicable, and provide the output symbol streams to the modulators (MOD) 232a - 232t. Each modulator 232 may process its respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator may further process the output sample stream (e.g., analog conversion, amplification, filtering, and upconversion) to obtain a downlink signal. The downlink signals from the modulators 232a - 232t may be transmitted via the antennas 234a - 234t, respectively.

[0036] In UE120, antennas 252a - 252r can receive downlink signals from base station 110 and can provide the received signals to demodulators (DEMOD) in transceivers 254a - 254r respectively. Each demodulator can adjust (e.g., filter, amplify, down - convert, and digitize) the respective received signal to obtain input samples. Each demodulator can further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 can obtain received symbols from all demodulators of transceivers 254a - 254r, can perform MIMO detection on the received symbols when applicable, and can provide the detected symbols. Receiving processor 258 can process (e.g., demodulate, de - interleave, and decode) the detected symbols, can provide decoded data for UE120 to data sink 260, and can provide the decoded control information to controller / processor 280.

[0037] In an MIMO system, a transmitter (e.g., BS110) includes a plurality of transmit antennas 234a - 234t, and a receiver (e.g., UE120) includes a plurality of receive antennas 252a - 252r. Thus, there are a plurality of signal paths 294 from transmit antennas 234a - 234t to receive antennas 252a - 252r. Each of the transmitter and the receiver can be implemented, for example, within UE120, BS110, or any other suitable wireless communication device.

[0038] By using such multi-antenna techniques, a wireless communication system can utilize the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. Spatial multiplexing can be used to simultaneously transmit different streams of data, also called layers, on the same time-frequency resource. The data streams may be transmitted to a single UE to increase the data rate, or may be transmitted to multiple UEs to increase the overall system capacity, the latter being referred to as multi-user MIMO (MU-MIMO). This is achieved by spatially precoding each data stream (i.e., multiplexing the data streams using different weightings and phase shifts) and then transmitting each spatially precoded stream on the downlink via multiple transmit antennas. The spatially precoded data streams arrive at the UE with different spatial signatures, whereby each UE can recover one or more of the data streams intended for that UE. On the uplink, each UE transmits a spatially precoded data stream, whereby the base station can identify the source of each spatially precoded data stream.

[0039] The number of data streams or layers corresponds to the transmit rank. Generally, the rank of a MIMO system is limited by the smaller of the number of transmit antennas or receive antennas. Additionally, other considerations such as the channel state at the UE and the available resources at the base station can also affect the transmit rank. For example, the rank (and thus the number of transmit layers) assigned to a particular UE on the downlink can be determined based on a rank indicator (RI) transmitted from the UE to the base station. The RI can be determined based on the antenna configuration (e.g., the number of transmit and receive antennas) and the signal-to-interference-plus-noise ratio (SINR) measured on each of the receive antennas. The RI can indicate, for example, the number of layers that can be supported under the current channel state. The base station can use the RI, along with resource information (e.g., the available resources and the amount of data to be scheduled for the UE), to assign the transmit rank to the UE.

[0040] On the uplink, at UE120, transmission processor 264 may receive data from data source 262 (e.g., for the physical uplink shared channel (PUSCH)) and control information from controller / processor 280 (e.g., for the physical uplink control channel (PUCCH)), and may process it. Transmission processor 264 may also generate reference symbols for reference signals (e.g., for the sounding reference signal (SRS)). Symbols from transmission processor 264 may be precoded by TX MIMO processor 266, if applicable, and further processed by a demodulator in transceivers 254a - 254r (e.g., for SC-FDM, etc.) and transmitted to base station 110. At BS110, the uplink signal from UE120 is received by antenna 234, processed by modulator 232, detected by MIMO detector 236, if applicable, and further processed by receive processor 238 to obtain the decoded data and decoded control information sent by UE120. Receive processor 238 may provide the decoded data to data sink 239 and the decoded control information to controller / processor 240.

[0041] Controllers / processors 240 and 280 may each direct operations at BS110 and UE120, respectively. Processor 240 in BS110 and / or other processors and modules may execute or direct the execution of processes for the techniques described herein. Memories 242 and 282 may each store data and program code for BS110 and UE120, respectively. Scheduler 244 may schedule UEs for data transmission on the downlink and / or uplink.

[0042] As described above, by using multi-antenna technology, a wireless communication system can utilize the spatial domain to support spatial multiplexing, beamforming, and transmit diversity.

[0043] FIG. 5 shows an exemplary system that utilizes beamforming and performs a beam training procedure. Beamforming generally refers to a mechanism that identifies the most efficient data delivery route to a particular user and reduces interference to nearby users during the process. Beamforming can help a base station and the UEs served by the base station (using hundreds of individual antennas in some cases) utilize the surrounding spectrum more efficiently. The main challenge of massive MIMO is to reduce interference while transmitting more information from many more antennas at once. Beamforming algorithms can identify the best transmission route to each user via the air. The beamforming algorithm can then send individual data packets in many different directions (even using reflections from objects in an accurately coordinated pattern). By carefully planning the packet route and arrival time, beamforming enables many users and multi-antenna base stations to exchange much more information at once.

[0044] In the case of a system that utilizes millimeter waves (high frequencies used in 5G networks), beamforming can help address other types of problems. For example, beamforming can help address the fact that millimeter wave signals are highly directional, are easily blocked by objects, and tend to weaken over long distances. In this case, beamforming can be useful by focusing the signal into a concentrated beam that points only in the direction of the user, rather than broadcasting in many directions at once. This approach can increase the likelihood that the signal reaches without being impaired and reduce interference to other users.

[0045] In some cases, beamforming can be adjusted using a procedure called beamforming training. In some cases, the training may involve the receiving device (e.g., a base station or UE) measuring phase information at each antenna for a given beam pair. For example, as shown in FIG. 3, the receiving device may measure and record the phase difference information while evaluating different beam pairs during the beam training procedure.

[0046] In the example shown in FIG. 3, the UE maintains a set of candidate beams (e.g., four beams). For each beam, the UE reports beam state information (BSI). The BSI may include the beam reference signal received power (BRSRP) for each beam (identified by the beam index). Typically, the UE reports the BSI for the beam with the highest BRSRP in the set of candidate beams. Channel state information (CSI) may refer to the channel characteristics of a communication link. The CSI may represent, for example, the combined effects of scattering, fading, and power attenuation due to the distance between the transmitter and the receiver. Channel estimation using pilots such as CSI reference signals (CSI-RS) may be performed to determine these effects on the channel. The CSI may be used to adapt the transmission based on the current channel state, which is particularly useful for achieving reliable communication with high data rates, especially in multi-antenna systems. The CSI is typically estimated, quantized, and fed back to the transmitter at the receiver.

[0047] Exemplary architecture for multi-user transmission using a lens antenna As described above, the use of multi-antenna technology enables a wireless communication system to utilize the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. This enables the support of a wideband architecture and may enable communication over a wide frequency range and / or multiple bands.

[0048] For example, wideband support may enable dual connectivity (DC) and inter-band carrier aggregation (CA). For example, inter-band CA may include defined frequency bands FR1 (sub-6 GHz) and FR2 (24.25 - 52.6 GHz), and may be extended to cover additional bands such as FR4 (which may be considered to include frequency bands above 52 GHz for example). Wideband support may also enable, for example, E-UTRAN New Radio - Dual Connectivity (EN-DC), where E-UTRAN refers to LTE and New Radio (NR) refers to 5G.

[0049] Aspects of the present disclosure propose using a lens antenna that uses a single lens to generate N beams in parallel to achieve beamforming across multiple bands. In some cases, the vulnerability of the lens antenna may be made more suitable for deployment by a (stationary) base station, but deployment in other devices (e.g., UEs) may be possible (e.g., as the tip material may enable a smaller / more robust lens antenna design).

[0050] Lens antennas generally perform real-time delay shifts (TTD: true-time-delay) that enable extremely wideband beamforming. The time shift is enabled by variable propagation path lengths within the lens and / or variable refractive indices within the lens. As will be described in more detail, metamaterials may be used in constructing lens antennas and / or other components in wideband architectures / multi-band architectures to achieve the desired results described herein.

[0051] The architecture proposed in this specification utilizes a lens antenna to generate multiple beams as an alternative to (or in addition to) the conventional use of multiple phased arrays. In some cases, the lens antenna may replace multiple phased antenna arrays, resulting in a significant reduction in complexity. For example, a conventional phased array antenna can be used to beamform a spherical wavefront into a collimated plane wave. However, such a phased array requires a phase shifter and a combiner / splitter for each beam, resulting in N phase shifters for N beams using N antennas. Another method of beamforming is the Butler matrix. The implementation of the Butler matrix may require N / 2 log2N directional couplers and phase shifters to generate N beams using N antennas. 2 In contrast, a lens antenna uses a single lens to generate N beams using real-time delay shift (TTD) to achieve (ultra) wideband beamforming. As described above, this can be achieved by variable propagation path lengths and / or variable refractive indices within the lens.

[0052] The lens antenna can be used in various applications that require multiple beams or ultra-wideband beams, such as local microwave distribution systems (LMDS) or other fixed link backhaul applications. In such applications, operators can use the lens antenna in a single band for high gain and / or high frequency (microwave), typically under an mmW license (e.g., 28.5 GHz, 29.3 GHz, etc.).

[0053]

[0054] ​However, aspects of the present disclosure propose an architecture that utilizes a lens antenna to generate N beams in parallel to achieve beamforming over a wide frequency range. For example, the architecture described herein may support inter-band CA for FR1, FR2, and / or FR4. Such an architecture may provide a single beamforming system that supports sub-6 GHz signals and millimeter wave signals, which conventionally required separate beamforming systems. A base station (which may include an access point) may utilize the architecture proposed herein to simultaneously transmit multiple data streams to multiple UEs.

[0055] FIG. 4 shows an exemplary operation 400 for wireless communication using a lens antenna, according to some aspects of the present disclosure.

[0056] Operation 400 begins, at 402, by providing N sets of radio frequency (RF) chains, where each RF chain in a given set is configured to generate or process RF signals for a different frequency band.

[0057] At 404, N combiners are provided, where each combiner generates a multi-band signal by combining RF signals for different frequency bands generated by at least two of the RF chains in the corresponding set of the N sets of RF chains, and is configured to supply the multi-band signal to a lens antenna for transmission via a first transmission beam.

[0058] Referring to the exemplary architecture shown in FIG. 5, each set of RF chains can handle signals for one beam (e.g., for one user). The term RF chain as used herein generally refers to the circuitry between an antenna and a signal processor (e.g., a digital baseband processor). A receive (RX) RF chain can include components within a receiver that process a signal at that RF before the incoming original radio frequency (RF) is converted to a lower intermediate frequency (IF), whereas, conversely, a transmit (TX) RF chain can include components that take out a lower IF signal and generate an RF signal for transmission.

[0059] As shown, a synthesizer (e.g., a diplexer in the example shown) can combine signal processing from a plurality of different bands (three in the example shown) and supply the combined multi-band signal to a port of a lens antenna. A diplexer can sometimes refer to a synthesizer that includes some filtering and corresponding frequency selectivity (e.g., while obtaining one band, other bands can be rejected). In some cases, the TX RF chain and / or the RX RF chain may have their filtering, making it unnecessary to include filtering in the synthesizer.

[0060] As shown, each of the N sets of RF chains can have a similar synthesizer for supplying to respective ports of a lens antenna corresponding to beams (e.g., for different users). In some cases, two or more of the N beams can be for the same user. On the receive (RX) side, the combined RF signal can be supplied from the port to the corresponding RX RF chain. As shown, in some cases, a transmit / receive switch (or duplexer) can be used to route the Tx RF signal from each Tx RF chain (corresponding to different bands) to the lens antenna port (via the synthesizer) and route the Rx RF signal from the lens antenna port to the corresponding Rx RF chain (via the synthesizer / demultiplexer).

[0061] Figures 6 and 7 show exemplary lens antennas that can be utilized in the exemplary architectures presented herein.

[0062] As shown, a lens antenna generally has M feed ports and a lens. The lens can function as an aperture or can excite an antenna or an array of antennas to generate up to N beams (as shown in the configuration below Figure 6), where M ≥ N (for example, in which case some ports may have to be terminated). Lens antennas can be broadly classified by shape (e.g., spherical, hyperhemispherical, etc.) and / or refractive index uniformity (e.g., uniform or non-uniform). In some cases, the feed ports can feed a reflector lens as shown in the configuration below Figure 7.

[0063] Benefits of using lens antennas can include that all beams are simultaneously available, support for multiple beams, wideband signals (e.g., time-shifted vs. phase-shifted), low insertion loss (due to few interconnections), good separation between feed ports, and the ability to support agile beam switching. These improvements have reduced bulk, size, and / or vulnerability and have led to a significant reduction in the manufacturing difficulty of lens antennas. Such improvements include, for example, the use of metasurfaces (metamaterials), 2D planar architectures, and smaller apertures (e.g., for millimeter-wave signals).

[0064] In some cases, a particular type of amplifier configuration may be used to power the lens antenna portion. For example, a lens antenna, by definition, maps one port per beam, which may require a relatively large PA compared to a phased array when the power amplifier (PA) is necessarily distributed. This can pose a challenge when using a lens antenna because, for a given semiconductor process / geometry / supply voltage, a larger PA can be difficult to design. However, aspects of the present disclosure propose a configuration that synthesizes power from multiple PAs using an N-way power combiner. Such a configuration may be designed to mitigate mismatches in each branch of the combiner and may include distributed PAs and / or stacked PAs.

[0065] In some cases, metamaterials and / or metasurfaces may be used to achieve desired properties (of the lens antenna and / or components of the RF chain). As used herein, a metamaterial may refer to any material, generally artificial, whose permittivity and / or permeability is adjustable and does not exist in nature. The recent evolution of metamaterials and / or metasurfaces has been enabled by nanofabrication methods. In addition to lens antennas, almost all components within the RF chain can also be designed using metamaterials (e.g., antennas, switches, phase shifters, waveguides, couplers, filters / resonators, oscillators, diplexers / circulators, etc.). Metamaterials may be used to achieve a desired refractive index (the refractive index being a function of permittivity and permeability according to Maxwell's equations (Snell's law)) and may be designed for negative permittivity and / or negative permeability and thus, negative refractive index.

[0066] Metamaterials are sometimes also referred to as left-handed materials, epsilon negative (ENG: Epsilon negative) materials, double-negative materials, negative refractive index materials, or chiral materials. Examples of applications of such materials in wireless communication include reconfigurable antennas (e.g., for dynamic beamforming), electrically small antennas (smaller than λ / 10) that maintain high efficiency and bandwidth, wireless transmissive antennas that enable antenna stacking and limit scattering and mutual coupling. Other exemplary applications include phase shifters implemented by adjusting the dielectric of waveguides, including non-magnetic circulators, which are required for multiplexing and lower insertion loss. Metamaterials may also be designed for use in circuits from sub-6 GHz to several THz and can have very low power consumption and may be used, for example, to design super-resolution lenses operating below the diffraction limit.

[0067] Figures 8-11 show exemplary architectures that utilize a lens antenna for wideband beamforming according to aspects of the present disclosure. In some cases, the same components may be used to achieve various architectures. For example, configurable switches may be controlled to route signals from RF chains and / or synthesizers to achieve the architectures shown in Figures 8-11. This can provide flexibility when reconfiguring a given device or adapting modules for use in different devices.

[0068] A diplexer is shown in each of Figures 8-11 for illustration purposes, but the synthesizer may be implemented as a diplexer / triplexer / quadruplexer or any other passive frequency division (FD) multiplexer or Wilkinson synthesizer (depending on the number of bands). As described above, the power amplifier (PA) may be distributed, stacked, or combined for higher power.

[0069] FIG. 8 shows an exemplary architecture for wideband time-division duplex (TDD) multi-user transmission using a lens antenna according to some aspects of the present disclosure.

[0070] The architecture of FIG. 8 can be implemented in a gNB, for example, to simultaneously transmit N ultra-wideband beams (e.g., over FR1, FR2, and / or FR4) to up to N UEs in time-division duplex (TDD) mode. As shown, a transmit / receive (T / R) switch can be used to toggle between downlink (DL) communication (where the port supplies an RF signal from the TX RF chain to the lens antenna) and uplink (UL) communication (where the received RF signal is routed from the lens antenna to the RX RF chain). Using a diplexer, for example, simultaneous RX and TX such as TX on some ports and Rx (or both) on other ports can be performed. As an example, DL transmission can be sent on band 1, while UL transmission is received on band 2, and band 3 can be used for some UL and some DL.

[0071] FIG. 9 shows an exemplary architecture for wideband frequency-division duplex (FDD) multi-user transmission using a lens antenna according to some aspects of the present disclosure.

[0072] The architecture of FIG. 9 can be implemented in a gNB, for example, to simultaneously transmit N ultra-wideband beams (e.g., over FR1, FR2, and / or FR4) to up to N UEs in frequency-division duplex (FDD) mode. The FDD mode can enable, for example, UL on one band and DL on another band (e.g., supplementary UL and supplementary DL as defined in Release 15 / 16), and the specific UL and DL band options are shown for illustrative purposes only.

[0073] FIG. 10 shows an exemplary architecture for wideband full-duplex multi-user transmission via spatial multiplexing using a lens antenna according to some aspects of the present disclosure.

[0074] The architecture of FIG. 10 can be implemented in the gNB, for example, to transmit N ultra-wideband beams in space division (SD) full-duplex mode to up to N / 2 UEs simultaneously. In other words, this configuration can enable parallel DL and UL on separate beams. In the illustrated example, the combination of Band 1, Band 2, and Band 3 (the top three within the TX) is combined on the first beam (Port 1) for DL, while the second beam (Beam 2) is used to receive the combined UL RF signal supplied to the RX RF chain via Port 2. In this configuration of separate ports for UL and DL, if there are N possible beams, N / 2 users can be supported.

[0075] FIG. 11 shows an exemplary architecture for wideband full-duplex multi-user transmission on each beam using a lens antenna, according to some aspects of the present disclosure.

[0076] The architecture of FIG. 11 can be implemented in the gNB, for example, to transmit N ultra-wideband beams to up to N UEs simultaneously in full-duplex mode for each beam. As shown, a duplexer (e.g., a circulator, a branch-line coupler, or any other directional coupler) can be used for parallel DL and UL.

[0077] In some cases, the circuit configuration can be used to perform corrections due to imperfections of the duplexer (which may cause self-interference). As shown, separate analog components can be used for such corrections and / or digital cancellation can be performed in a processor (e.g., a digital baseband processor).

[0078] The method disclosed in this specification comprises one or more steps or actions for achieving the method. The steps and / or actions of the method may be exchanged with each other without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0079] Means for receiving or means for obtaining may include a receiver or antenna 234 (such as the receiver unit 232) of the access point 110 shown in FIG. 2, or the receiver unit 254 or antenna 252 of the station 120. Means for transmitting or means for outputting may include a transmitter or antenna 234 (such as the transmitter unit 232) of the access point 110 shown in FIG. 2, or the transmitter unit 254 or antenna 252 of the station 120. Means for generating, means for processing, means for supplying, means for amplifying, means for removing self-interference, and / or means for routing may include a processing system including one or more processors such as the RX data processor 238, TX data processor 220, TX spatial processor 230, RX spatial processor, or controller 240 of the access point 110 shown in FIG. 2, or the RX data processor 258, TX data processor 264, TX spatial processor 266, RX spatial processor, or controller 280 of the station 120.

[0080] In some cases, instead of actually transmitting a frame, the device may have an interface (means for outputting) for outputting the frame for transmission. For example, a processor may output a frame to a radio frequency (RF) front end for transmission via a bus interface. Similarly, instead of actually receiving a frame, the device may have an interface (means for obtaining) for obtaining a frame received from another device. For example, a processor may obtain (or receive) a frame from an RF front end for reception via a bus interface.

[0081] The phrase "at least one of" as used herein in reference to a list of items refers to any combination of those items including a single member. As an example, "at least one of a, b, or c" covers a, b, c, a - b, a - c, b - c, and a - b - c, as well as any combination having multiple of the same element (e.g., a - a, a - a - a, a - a - b, a - a - c, a - b - b, a - c - c, b - b, b - b - b, b - b - c, c - c, and c - c - c, or a, b, and c in any other order).

[0082] The term "determining" as used herein encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or another data structure), ascertaining, etc. Also, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. Further, "determining" may include resolving, selecting, choosing, establishing, etc.

[0083] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein but are to be accorded the full scope consistent with the language of the claims, and the reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless otherwise specified, the term “some” refers to one or more. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure that are known or later come to be known to those skilled in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. A claim element is not to be construed under the provisions of 35 U.S.C. § 112, paragraph (f) unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is expressly recited using the phrase “step for.”

[0084] The various operations of the methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include, but are not limited to, various hardware and / or software component and / or modules including a circuit, an application specific integrated circuit (ASIC), or a processor. For example, the various processors shown in FIG. 2 may be configured to perform operation 400 of FIG. 4.

[0085] The various illustrative logical blocks, modules, and circuits described in connection with the present disclosure may be implemented or executed using one or more (or combinations thereof) of a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0086] When implemented in hardware, an exemplary hardware configuration may include a processing system within a wireless node. The processing system may be implemented using a bus architecture. The bus may include any number of interconnecting buses and bridges, depending on the specific application of the processing system and overall design constraints. The bus may link various circuits including a processor, a machine-readable medium, and a bus interface to each other. The bus interface may be used to connect, among other things, a network adapter to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In the case of user terminal 120 (see FIG. 1), a user interface (e.g., keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits such as a timing source, peripherals, voltage regulators, power management circuits, etc., which are well known in the art and thus will not be described further. The processor may be implemented using one or more general-purpose processors and / or dedicated processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuit configurations capable of executing software. Those skilled in the art will recognize the best way to implement the described functions for the processing system, depending on the specific application and overall design constraints imposed on the overall system.

[0087] When implemented in software, the functions can be stored on a computer-readable medium as one or more instructions or code, or can be transmitted via a computer-readable medium. Software is broadly interpreted to mean instructions, data, or any combination thereof, whether called software, firmware, middleware, microcode, hardware description language, or otherwise. A computer-readable medium includes both a computer storage medium and a communication medium that facilitates transfer of a computer program from one place to another. A processor may be in charge of managing the bus and general processing, including execution of software modules stored on a machine-readable storage medium. A computer-readable storage medium can be coupled to the processor such that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integral to the processor. By way of example, a machine-readable medium may include a transmission line, a carrier wave modulated by data, and / or a computer-readable storage medium having instructions stored thereon separate from a wireless node, all of which can be accessed by the processor through a bus interface. Alternatively or additionally, a machine-readable medium or any portion thereof may be integrated into the processor, optionally with a cache and / or a general purpose register file. Examples of machine-readable storage media may include, by way of example, RAM (Random Access Memory), flash memory, ROM (Read Only Memory), PROM (Programmable Read Only Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), registers, magnetic disks, optical disks, hard drives, or any other suitable storage medium, or any combination thereof. A machine-readable medium may be embodied in a computer program product.

[0088] A software module may comprise a single instruction or many instructions and may be distributed across several different code segments, between different programs, and across multiple storage media. A computer-readable medium may comprise several software modules. A software module, when executed by an apparatus such as a processor, includes instructions that cause a processing system to perform various functions. A software module may include a sending module and a receiving module. Each software module may reside within a single storage device or may be distributed across multiple storage devices. By way of example, a software module may be loaded from a hard drive into RAM when a trigger event occurs. During execution of a software module, the processor may load some of the instructions into a cache to increase access speed. One or more cache lines may then be loaded into a general-purpose register file for the processor to execute. When referring hereinafter to the functions of a software module, it will be understood that such functions are implemented by the processor when executing instructions from that software module.

[0089] Also, any connection is properly called a computer-readable medium. For example, when software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared (IR), wireless, and microwave, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, wireless, and microwave are included in the definition of the medium. As used herein, disk and disc include compact disc (CD), laser disc (registered trademark), optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray (registered trademark) disc, where disk typically magnetically reproduces data and disc optically reproduces data using a laser. Thus, in some embodiments, a computer-readable medium may comprise a non-transitory computer-readable medium (e.g., a tangible medium). Additionally, in other embodiments, a computer-readable medium may comprise a transitory computer-readable medium (e.g., a signal). The above combinations should also be included within the scope of computer-readable media.

[0090] Accordingly, some embodiments may comprise a computer program product for performing the operations presented herein. For example, such a computer program product may comprise a computer-readable medium having instructions stored (and / or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein (e.g., the operations described herein and shown in FIGS. 8 and 9).

[0091] Furthermore, it should be understood that modules and / or other suitable means for performing the methods and techniques described herein can be downloaded and / or otherwise obtained by a user terminal and / or a base station, where applicable. For example, such a device can be coupled to a server to facilitate transfer of means for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage means (e.g., a physical storage medium such as RAM, ROM, compact disk (CD), or floppy disk) such that the user terminal and / or base station can obtain the various methods when the storage means is coupled to or provided to the device. Additionally, any other suitable technique for providing the methods and techniques described herein to a device can be utilized.

[0092] It should be understood that the claims are not limited to the exact configurations and components shown above. Various modifications, changes, and variations may be made to the configurations, operations, and details of the methods and apparatuses described above without departing from the scope of the claims.

Description of Reference Numerals

[0093] 100 Wireless communication network 102a, 102b, 102c Macrocell 102x Picocell 102y, 102z Femtocell 110 Base station (BS) 120 User equipment (UE) 130 Network controller 212 Data source 220 Transmission processor 230 Transmission (TX) multiple-input multiple-output (MIMO) processor 232 Modulator (MOD) 234 Antenna 234a~234t Transmission antennas 236 MIMO detector 238 Reception processor 239 Data sink 240 Controller / Processor 242 Memory 244 Scheduler 252 Antenna 252a~252r Receiver Antenna 254 Transceiver 254a~254r Transceiver 256 MIMO Detector 258 Receiver Processor 260 Data Sink 262 Data Source 264 Transmitter Processor 266 Transmit (TX) Multiple-Input Multiple-Output (MIMO) Processor 280 Controller / Processor 282 Memory 294 Signal Path 400 Operation

Claims

1. An apparatus for wireless communication, comprising: A first set of radio frequency (RF) chains, each RF chain of the first set being configured to generate or process RF signals for different frequency bands; A first synthesizer, configured to generate a first multi-band signal by synthesizing RF signals for different frequency bands generated by at least two of the RF chains of the first set, and to supply the first multi-band signal to a first port of a lens antenna for transmission via a first transmission beam; A first synthesizer configured as such; A second set of radio frequency (RF) chains, each RF chain of the second set being configured to generate or process RF signals for different frequency bands; A second synthesizer, configured to generate a second multi-band signal by synthesizing RF signals for different frequency bands generated by at least two of the RF chains of the second set, and to supply the second multi-band signal to a second port of the lens antenna for transmission via a second transmission beam; A second synthesizer configured as such; An apparatus including the above.

2. The apparatus further includes: N sets of RF chains, the N sets including the first and second sets of RF chains, each RF chain of a given one of the N sets of RF chains being configured to generate or process RF signals for different frequency bands; N synthesizers, the N synthesizers including the first and second synthesizers, each of the N synthesizers being configured to generate a multi-band signal by synthesizing RF signals for different frequency bands generated by at least two of the RF chains of the corresponding set of the N sets of RF chains, and to supply the multi-band signal to the lens antenna for transmission via a transmission beam; Including the above. One or more of the N sets of the RF chains include at least two RF chains configured to generate RF signals for the first and second frequency bands and at least one RF chain configured to process RF signals for the third frequency band. The apparatus according to claim 1.

3. The first set of the RF chains includes at least two RF chains configured to generate RF signals for the first and second frequency bands and at least one RF chain configured to process RF signals for the third frequency band. The second set of the RF chains includes at least two RF chains configured to generate RF signals for the first and second frequency bands and at least one RF chain configured to process RF signals for the third frequency band. The apparatus according to claim 1.

4. The first set of the RF chains includes at least one amplifier of a distributed type, a stacked type, or a combined type configured to amplify the first multi-band signal. The second set of the RF chains includes at least one amplifier of a distributed type, a stacked type, or a combined type configured to amplify the second multi-band signal. The apparatus according to claim 1.

5. The apparatus according to claim 1, wherein at least one of the components in the first set of the RF chains or the components in the second set of the RF chains includes a metamaterial.

6. The first and second sets of the RF chains include an analog circuit configuration configured to remove self-interference, or The apparatus further includes a digital circuit configuration configured to remove self-interference. The apparatus according to claim 1.

7. The first set of the RF chains includes, for each of the different frequency bands, a first transmit RF chain for generating an RF signal to be output for transmission to a first wireless node during a transmit portion of a time-division duplex (TDD) mode, and a first receive RF chain for processing an RF signal acquired from the first wireless node via the lens antenna during a receive portion of the TDD mode. The second set of the RF chains includes, for each of the different frequency bands, a second transmit RF chain for generating an RF signal to be output for transmission to a second wireless node between the transmission portions of the TDD mode, and a second receive RF chain for processing an RF signal acquired from the second wireless node via the lens antenna between the reception portions of the TDD mode. The first set of the RF chains further includes a switch configured to route, for each of the different frequency bands, the RF signal generated by the first transmit RF chain to the first synthesizer between the transmission portions of the TDD mode, and to route the RF signal acquired from the first synthesizer via the lens antenna to the first receive RF chain between the reception portions of the TDD mode. The second set of the RF chains further includes a switch configured to route, for each of the different frequency bands, the RF signal generated by the second transmit RF chain to the second synthesizer between the transmission portions of the TDD mode, and to route the RF signal acquired from the second synthesizer via the lens antenna to the second receive RF chain between the reception portions of the TDD mode. The apparatus according to claim 1.

8. The first set of the RF chains includes at least two RF chains configured to generate RF signals for the first and second frequency bands to be output for transmission to a first wireless node via the lens antenna, and at least one RF chain configured to process an RF signal for at least a third frequency band acquired from the first wireless node via the lens antenna. The second set of the RF chains includes at least two RF chains configured to generate RF signals for the first and second frequency bands to be output for transmission to a second wireless node via the lens antenna, and at least one RF chain configured to process an RF signal for at least the third frequency band acquired from the second wireless node via the lens antenna. The first and second frequency bands include a sub-6 GHz frequency band. wherein the third frequency band includes a millimeter wave (mmWave) frequency band The apparatus according to claim 1 **Claim 9** wherein the first set of RF chains includes at least two RF chains configured to generate RF signals for the first and second frequency bands to be output for transmission to a first wireless node via the lens antenna on a first beam, and at least two RF chains configured to process RF signals for the first and second frequency bands obtained from the first wireless node via the lens antenna on a second beam wherein the second set of RF chains includes at least two RF chains configured to generate RF signals for the first and second frequency bands to be output for transmission to a second wireless node via the lens antenna on a third beam, and at least two RF chains configured to process RF signals for the first and second frequency bands obtained from the second wireless node via the lens antenna on a fourth beam, and / or wherein the first set of RF chains includes at least two RF chains configured to generate RF signals for the first and second frequency bands to be output for transmission to a first wireless node via the lens antenna on a first beam, and at least two RF chains configured to process RF signals for the first and second frequency bands obtained from the first wireless node via the lens antenna on the first beam wherein the second set of RF chains includes at least two RF chains configured to generate RF signals for the first and second frequency bands to be output for transmission to a second wireless node via the lens antenna on a second beam, and at least two RF chains configured to process RF signals for the first and second frequency bands obtained from the second wireless node via the lens antenna on the second beam The apparatus according to claim 1 **Claim 10** wherein the lens antenna includes a metamaterial wherein the apparatus further includes at least one antenna and is configured as a wireless node The apparatus according to claim 1.

11. An apparatus for wireless communication, N sets of radio frequency (RF) chains, wherein each RF chain of a given set is configured to generate or process RF signals for different frequency bands, the N sets of RF chains; N combiners, wherein each combiner generates a multi-band signal by combining RF signals for different frequency bands generated by at least two of the RF chains of the corresponding set of the N sets of RF chains, and supplies the multi-band signal to a corresponding port of a lens antenna for transmission via a corresponding transmission beam, the N combiners An apparatus comprising.

12. One or more of the N sets of RF chains includes at least two RF chains configured to generate RF signals for first and second frequency bands and at least one RF chain configured to process RF signals for a third frequency band, The apparatus further includes at least one antenna, and the apparatus is configured as a wireless node. The apparatus according to claim 11.

13. A method for wireless communication, Providing N sets of radio frequency (RF) chains, wherein each RF chain of a given set is configured to generate or process RF signals for different frequency bands; Providing N combiners, wherein each combiner generates a multi-band signal by combining RF signals for different frequency bands generated by at least two of the RF chains of the corresponding set of the N sets of RF chains, and supplies the multi-band signal to a corresponding port of a lens antenna for transmission via a corresponding transmission beam A method comprising.

14. One or more of the N sets of RF chains includes at least two RF chains configured to generate RF signals for first and second frequency bands and at least one RF chain configured to process RF signals for a third frequency band, The method according to claim 13.

15. A computer program that, when executed by a computer, comprises instructions for causing the computer to execute the method according to claim 13 or 14.

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