US-12620703-B2 - Radio sheet system at high frequencies

US12620703B2US 12620703 B2US12620703 B2US 12620703B2US-12620703-B2

Abstract

The embodiments herein relate to radio sheet system at high frequencies. In an embodiment, there proposes a lens antenna system, comprising: a lens; a plurality of antenna sets attached to the lens; and a multiplexer connected to the plurality of antenna sets, for selectively activating an antenna set of the plurality of antenna sets, in order that a collimated beam is emitted through the lens from the activated antenna set. With embodiments herein, only one antenna is used to transmit a beamformed beam by lens with collimation capability, thus the embodiments may provide an alternative and more efficient way to replace beamforming functionality.

Inventors

YI GENG
Pål Frenger

Assignees

TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

Dates

Publication Date: 20260505
Application Date: 20201218

Claims (16)

1 . A lens antenna system, comprising: a lens; a plurality of antenna sets attached to the lens; and a multiplexer connected to the plurality of antenna sets, for selectively activating an antenna set of the plurality of antenna sets, in order that a collimated beam is emitted through the lens from the activated antenna set, wherein the lens includes a Luneburg lens, and the plurality of antenna sets are located within the range of a circular cone with the center of the Luneburg lens as the vertex and with a cone angle of 90 degrees or less.
2 . The lens antenna system according to claim 1 , wherein the plurality of antenna sets are located on the surface of the lens.
3 . The lens antenna system according to claim 1 , further comprising: an antenna processing unit (APU) connected to the multiplexer, for providing a signal to be handled by the activated antenna set and a signal for the selectively activating.
4 . The lens antenna system according to claim 1 , wherein the activated antenna set is selectively activated according to a direction or position of a User Equipment (UE).
5 . The lens antenna system according to claim 1 , wherein at least two of the plurality of antenna sets are selectively activated in a duplex approach, to provide service to a plurality of User Equipments (UEs).
6 . The lens antenna system according to claim 1 , wherein each of the plurality of antenna sets includes a pair of antenna elements with perpendicular polarization directions.
7 . The lens antenna system according to claim 3 , wherein the multiplexer includes a logic gate electronics including at least one digital switch, and wherein the multiplexer is integrated with the APU.
8 . A sheet antenna system, comprising: a sheet base; a plurality of lens antenna systems on the sheet base in a mesh pattern; a plurality of interconnects, each of the plurality of interconnects is used for connecting at least two of the plurality of lens antenna systems; padding material for wrapping the plurality of lens antenna systems and the plurality of interconnects; and covering material, for covering the sheet base, the plurality of lens antenna systems, the plurality of interconnects, and the padding material, wherein at least one of the plurality of lens antenna systems includes a lens antenna system comprising: a lens; a plurality of antenna sets attached to the lens; and a multiplexer connected to the plurality of antenna sets, for selectively activating an antenna set of the plurality of antenna sets, in order that a collimated beam is emitted through the lens from the activated antenna set.
9 . The sheet antenna system according to claim 8 , further comprising: at least one connector, connected to another sheet antenna system.
10 . The sheet antenna system according to claim 8 , further comprising: at least one connector, connected to a power source.
11 . The sheet antenna system according to claim 8 , wherein each of the plurality of interconnects is used for providing synchronization, data transfer, and power supply for the lens antenna systems connected thereto.
12 . The sheet antenna system according to claim 8 , wherein the plurality of lens antenna systems are located in a two-dimensional array, and wherein the plurality of interconnects include a plurality of row interconnects for connecting a plurality of lens antenna systems in the same row respectively and a plurality of column interconnects for connecting a plurality of lens antenna systems in the same column respectively.
13 . The sheet antenna system according to claim 8 , wherein the sheet base comprises a flexible film.
14 . The sheet antenna system according to claim 8 , wherein a plurality of collimated beams are emitted respectively from at least two of the plurality of lens antenna systems in the sheet antenna system to a same User Equipment (UE).
15 . The sheet antenna system according to claim 8 , wherein the sheet antenna system forms a part of a distributed massive Multiple Input Multiple Output (MIMO) system.
16 . A sheet antenna system, comprising: a sheet base; a plurality of lens antenna systems on the sheet base in a mesh pattern; and a plurality of interconnects, each of the plurality of interconnects is used for connecting at least two of the plurality of lens antenna systems, wherein at least one of the plurality of lens antenna systems includes a lens antenna system comprising: a lens; a plurality of antenna sets attached to the lens; and a multiplexer connected to the plurality of antenna sets, for selectively activating an antenna set of the plurality of antenna sets, in order that a collimated beam is emitted through the lens from the activated antenna set, wherein the plurality of lens antenna systems are located in a two-dimensional array; and wherein the plurality of interconnects include a plurality of row interconnects for connecting a plurality of lens antenna systems in the same row respectively and a plurality of column interconnects for connecting a plurality of lens antenna systems in the same column respectively.

Description

This application is a 35 U.S.C. § 371 national phase filing of International Application No. PCT/CN2020/137630, filed Dec. 18, 2020, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The embodiments herein relate generally to the field of wireless communication, and more particularly, the embodiments herein relate to radio sheet system at high frequencies. BACKGROUND Cell-Free Massive MIMO Communications The combination of Massive MIMO (Multiple Input Multiple Output) operation, dense distributed network topology, and user-centric transmission design creates a new concept, referred to as cell-free massive MIMO, also called distributed massive MIMO, as illustrated in FIG. 1. The word “cell-free” signifies that at least from a user equipment's perspective, there are no cell boundaries during data transmission, while all (or a subset of) Access Points (APs) in the network cooperate to jointly serve the user equipment in a UE-centric fashion. The APs are connected via front-haul connections to central processing units (CPUs), which are configured for the coordination. The CPUs are in turn connected with each other via back-haul connection. The cellular or cell boundary concepts disappear in cell-free massive MIMO and the UEs are served simultaneously by all nearby antennas. Radio Stripe System The radio stripe system is a visionary concept where base stations and antennas thereon are rethought. This revolutionary new mobile network design is super-distributed, it has the potential to deliver better quality, easier deployment, at a nearly invisible form factor, and enables truly ubiquitous high capacity radio everywhere. In radio stripe system, the antennas and the associated antenna processing units (APUs) are serially located inside a same cable, which also provides synchronization, data transfer, and power supply via a shared bus, as showed in FIG. 2. The APs consist of antenna elements and circuit-mounted chips (including power amplifiers, phase shifters, filters, modulators, and A/D and D/A converters) inside the protective casing of a cable or a stripe. Radio stripe system is designed wherein antenna elements and the associated antenna processing hardware are located inside the same cable. Luneburg Lens Luneburg lens is a spherical lens that a point source located at any point of the lens surface originates a collimated beam in the opposite direction. This property is independent of the lens diameter. One of the application scenarios of the Luneburg lens is signal relay, in which the incoming signal is amplified by the antenna on the surface of the Luneburg lens, and then an amplified collimated outgoing beam may be obtained. Baseband Processing There are daunting demands for baseband processing and beamforming processing at high frequency bands. Even for small-scale Distributed-MIMO (D-MIMO) prototyping system the baseband processing demand is daunting. For example, in a prototype with 16 APs and 16 UEs, each AP and UE is equipped with 8 antennas, and baseband processing is performed by 8 BPUs (baseband processing unit) and each BPU has Intel Xeon 72 core processors (576 CPU cores totally) in FIG. 3. Beamforming Processing In a digital beamforming architecture, each antenna element is equipped with its own RF chain and data converters (ADC and DAC). FIG. 4 is a schematic diagram showing a transmitting part of a digital beamforming architecture. Having an RF chain and data converter for each antenna element provides the highest performance and flexibility. Multi-antenna techniques such as spatial multiplexing and interference suppression can reach its full potential when used in a fully digital array. However, a fully digital array can also be expensive in terms of cost and power consumption. These aspects are particularly pronounced at millimeter-wave frequencies, since the number of antenna elements is expected to be large in order to populate a sufficiently large physical antenna area that can achieve a required link budget. Furthermore, the large bandwidth foreseen to be used at these frequencies requires the data converters to operate at high sampling rates, leading to high power consumption and heat generation. A large bandwidth coupled with many digitized antenna elements is also challenging from a shear data shuffling perspective, putting high demands on data interfaces between the antenna array and signal processing units. This also leads to high demands on signal processing capacity. Therefore, a fully digital array is currently a likely implementation only in the low frequency bands. In millimeter-wave bands, analog and hybrid array architectures will be prevalent, at least in the near future. Due to above drawbacks, it is hard to implement digital beamforming at high frequency bands when the number of antennas of each AP increases, especially in radio stripe system with huge number of APs. Even taking into account the use of analog beamforming, operati