HIGH GAIN ACTIVE RELAY ANTENNA SYSTEM
1. A high gain active relay antenna system, comprising:
- a first antenna pair having a first receive antenna and a first transmit antenna configured to communicate first wireless signals in a forward link from a base station to a plurality of users;
a second antenna pair having a second receive antenna and a second transmit antenna configured to communicate second wireless signals in a return link from the plurality of users to the base station; and
a first active relay section and a second active relay section configured to provide an adjustable power gain in the first and second wireless signals,wherein the first active relay section is coupled between the first receive antenna and the first transmit antenna, and the second active relay is coupled between the second receive antenna and the second transmit antenna.
Examples disclosed herein relate to a high gain active relay antenna system. The active relay antenna system comprises a first antenna pair having a first receive antenna and a first transmit antenna to communicate wireless signals in a forward link from a base station to a plurality of users; and a second antenna pair having a second receive antenna and a second transmit antenna to communicate wireless signals in a return link from the plurality of users to the base station. The active relay antenna system further comprises a first active relay section and a second active relay section to provide for adjustable power gain in the wireless signals.
- 1. A high gain active relay antenna system, comprising:
a first antenna pair having a first receive antenna and a first transmit antenna configured to communicate first wireless signals in a forward link from a base station to a plurality of users; a second antenna pair having a second receive antenna and a second transmit antenna configured to communicate second wireless signals in a return link from the plurality of users to the base station; and a first active relay section and a second active relay section configured to provide an adjustable power gain in the first and second wireless signals, wherein the first active relay section is coupled between the first receive antenna and the first transmit antenna, and the second active relay is coupled between the second receive antenna and the second transmit antenna.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- 11. A high gain active relay antenna system, comprising:
a phased array receive antenna comprising a plurality of receive antenna elements; a power combining network coupled to the phased array receive antenna; a phased array transmit antenna comprising a plurality of transmit antenna elements; a power dividing network coupled to the phased array transmit antenna; and a plurality of active relays coupled between the power combining network and the power dividing network and configured to provide an adjustable power gain to wireless signals received at the phased array receive antenna and transmitted by the phased array transmit antenna.
- View Dependent Claims (12, 13, 14, 15, 16, 17)
- 18. A method for operation of a high gain active relay antenna system, comprising:
receiving, via a first receive antenna, forward wireless signals in a forward link from a base station; transmitting, via a first transmit antenna, the forward wireless signals in the forward link to a plurality of users; receiving, via a second receive antenna, return wireless signals in a return link from the plurality of users; transmitting, via a second transmit antenna, the return wireless signals in a return link to the base station; adjusting, by a first active relay section, a gain of the forward wireless signals; and adjusting, by a second active relay section, a gain of the return wireless signals,
- View Dependent Claims (19, 20)
The present application claims priority to U.S. Provisional Patent Application Ser. No. 62/753,745, filed on Oct. 31, 2018, which is incorporated by reference in its entirety.
New generation wireless networks are increasingly becoming a necessity to accommodate user demands. Mobile data traffic continues to grow every year, challenging the wireless networks to provide greater speed, connect more devices, have lower latency, and transmit more and more data at once. Users now expect instant wireless connectivity regardless of the environment and circumstances, whether it is in an office building, a public space, an open preserve, or a vehicle. In response to these demands, a new wireless standard known as the fifth generation new radio (“5G NR”) has been designed for deployment in the near future. The fifth generation (“5G”) standards extend operations to millimeter wave bands, which covers frequencies beyond 6 gigahertz (“GHz”), and to planned 24 GHz, 26 GHz, 28 GHz, and 39 GHz, and up to 300 GHz, all over the world.
The millimeter wave spectrum provides narrow wavelengths in the range of approximately one to ten millimeters, which are susceptible to high atmospheric attenuation and have to operate over short ranges (about one kilometer or so). In millimeter wave systems, array antennas present several advantages by providing high gain, narrow beams, and beam steerability. For dense-scattering areas (e.g., street canyons, in buildings, and in shopping malls), due to multipath by shadowing and geographical obstructions, blind spots may exist. For remote areas, where the ranges are longer and sometimes extreme climatic conditions with heavy precipitation exist, operators are prevented from using large array antennas due to strong winds and storms. These and other challenges in providing millimeter wave wireless communications for 5G networks impose stringent requirements on system design, including the ability to generate desired beamforms at a controlled direction, while avoiding interference among the many signals and structures of the surrounding environment. Compared to previously deployed relay scenarios, different millimeter wave band relay solutions would be required to meet the very different and varying operational requirements in terms of performance and cost.
The present application may be more fully appreciated in connection with the following detailed description taken in conjunction with the accompanying drawings, which may not be drawn to scale and in which like reference characters refer to like parts throughout, and in which:
A high gain active relay antenna system is disclosed. The high gain active relay antenna system is suitable for many different millimeter wave (“mm-wave”) applications, and can be deployed in a variety of different environments and configurations. Mm-wave applications are those operating with frequency allocations between 24 GHz and 300 GHz or a portion thereof, including 5G applications in the 24, 26, 28, 39, and 60 GHz range, among others. In various examples, the high gain active relay antenna system provides a high gain amplification of a wireless signal to connect with wireless devices and user equipment (“UE”) that are operational in complicated environments, including outdoors with obstructing structures (e.g., skyscrapers, buildings, trees, etc.), and non-line-of-sight areas and indoors with walls and constructs. The high gain active relay antenna system has an active amplification subsystem that is made of amplifiers in several stages, which may include low noise amplifier stages, gain-control attenuators, variable gain amplifier stages, and power amplifier stages.
Optional functionalities, such as filtering, phase shifting, beam-steering, beamforming (e.g., performed by beamforming networks), and matching (e.g., performed by matching networks (“MNs”), which may employ step-adjustable attenuators) may also be implemented. In particular, for relay solutions involving higher layers, such as the Media Access Control (“MAC”) layer, network layer processing, analog-to-digital conversion, digital-to-analog conversion, digital channelization filtering, and other physical layer functionalities may also be implemented. Frequency conversion operations in both up-conversion and down-conversion may also be implemented in the high gain active relay antenna system. The main applications supported by the disclosed high gain active relay antenna system include general wireless cellular communication network optimization in various scenarios (e.g., planned or temporary), which may include, for example, range extension of relay links, availability enhancements of radio links in extreme conditions, and all possible solutions for mission critical applications. The high gain active relay antenna system described hereinbelow provides a way for a network operator to provide ubiquitous coverage, and vastly improve coverage, at a low cost. The disclosed system can provide a basis for efficient network planning and optimization solutions in the context of network densification, which is one of the major 5G NR features.
It is appreciated that, in the following description, numerous specific details are set forth to provide a thorough understanding of the examples. However, it is appreciated that the examples may be practiced without limitation to these specific details. In other instances, well-known methods and structures may not be described in detail to avoid unnecessarily obscuring the description of the examples. Also, the examples may be used in combination with each other.
As shown with the dotted arrows, the path between the BS 102 and the UE 104 is blocked by obstructing objects 106, which may include an infrastructure(s) (e.g., high rise buildings), vegetation, and so on. The BS 102, the relay 100, and the UE 104 are positioned in a large turning angle ABC (“∠ABC”) configuration. The positioning of the relay 100 in this configuration enables the BS 102 to provide wireless coverage to the UE 104 at a high gain and, therefore, achieve the desired performance and wireless experience for the users (i.e. at the UEs (e.g., UE 104)). In various examples, the relay 100 includes two pairs of antennas, which include one antenna pair for the FWD link and another antenna pair for the RTN link. The FWD link antenna pair includes a FWD receive antenna 108 to receive signals transmitted from the BS 102, and a FWD transmit antenna 110 to relay (transmit) the signals to the UE 104 after power amplification of the signals by a FWD link active section 116 of the relay 100. The RTN link antenna pair includes a RTN receive antenna 112 to receive signals transmitted from the UE 104, and a RTN transmit antenna 114 to relay (transmit) the signals to the BS 102 after power amplification of the signals by a RTN link active section 118 of the relay 100. The antennas transmitting and receiving signals between the relay 100 and the UE 104 (i.e. the FWD transmit antenna 110 and the RTN receive antenna 112) are referred to as “access link antennas”. And, the antennas transmitting and receiving signals between the relay 100 and the BS 102 (i.e. the FWD receive antenna 108 and the RTN transmit antenna 114) are referred to as “backhaul link antennas”.
An active relay is located between each pair of relay antennas (e.g., a FWD active relay 116 is located between the FWD receive antenna 108 and the FWD transmit antenna 110, and a RTN active relay 118 is located between the RTN receive antenna 112 and the RTN transmit antenna 114). The active relays (i.e. FWD active relay 116 and RTN active relay 118) are designed to provide a high power gain, which boosts a weak signal plagued by propagation loss from the receive antenna (i.e. FWD receive antenna 108 and RTN receive antenna 112) to a specific gain level to drive the transmit antenna (i.e. FWD transmit antenna 110 and RTN transmit antenna 114). The relay 100 also includes support mounts, such as mount 120, to serve as support members for the antennas (i.e. FWD transmit antenna 110, RTN transmit antenna 114, FWD receive antenna 108, and RTN receive antenna 112) and the active relays (i.e. FWD active relay 116 and RTN active relay 118) of the relay 100. In should be noted that, in one or more examples, the relay 100 may comprise more than two pairs of antennas as is shown in
It is appreciated that the proposed architecture of the relay 100 with two antenna pairs and one active relay between the receive and transmit antennas of each antenna pair is particularly suitable for millimeter wave relay applications, where the backhaul link is typically a point-to-point link and the access link is a point-to-multipoint link. Further, the architecture of the relay 100 allows for a separation between the access link antennas (i.e. the FWD transmit antenna 110 and the RTN receive antenna 112) and the backhaul link antennas (i.e. the FWD receive antenna 108 and the RTN transmit antenna 114) so that they are optimized in an independent way without any constraint from each other (e.g., the access link antennas may be designed for a wide and/or shaped coverage area to provide optimized connectivity with UE(s) (e.g., UE 104), while the backhaul link antennas can be implemented with high directivity designs with narrow beams to compensate for the high path loss in the millimeter wave band), thereby alleviating the interference caused by other cells within the network. The backhaul link antennas can be optimally pointed to the BS(s) (e.g., BS 102), and the access link antennas can be pointed to the coverage area of the UE(s) (e.g., UE 104) at the best orientation angle.
Note that for an access link antenna, its gain is reduced when it is designed to cover a wide area with a wide beam. In such circumstances, the coverage area will not be large with the limited beamforming gain for these types of access link antennas. The access link antennas can be designed to form shaped beams (e.g., beams with specific shapes to cover an area in which most of the subareas are covered and some of the areas can be masked without signals reached). This is a unique feature of the disclosed two-antenna architecture for the relay 100. Also note that an active solution becomes necessary, and even indispensable, in millimeter wave wireless applications. The power amplification functionality provided by the active relays (e.g., FWD active relay 116 and RTN active relay 118) enables a power gain from some tens of dB up to over hundreds of dB to boost the relayed signal in both the downlink and uplink signals, thereby meeting the connectivity requirements in the access links.
In one example, illustrated in
Attention is now directed at
The antennas in the relay 300 may be array antennas designed for a specific application, environment (e.g., a city environment, a rural environment, etc.), and/or associated conditions (e.g., weather, population, etc.). In various examples, the antennas can be manufactured from metastructures, which are specially designed structures that manipulate electromagnetic signals to suite various applications. More specifically, metastructures are engineered, non- or semi-periodic structures that are spatially distributed to meet a specific phase and frequency distribution. A metastructure antenna can be designed with metastructure reflector elements that are very small relative to the wavelength of the wireless signals. The metastructure antennas are able to generate directed, narrow beams to improve wireless communications between UE and a BS serving the UE in a wireless network.
Each antenna can be made to be three-dimensionally (“3D”) maneuverable in roll, pitch, and yaw by using a suitable mechanical structure, such as illustrated with antenna 306 (e.g., a phased array antenna) in
Another example implementation of an active relay architecture is shown in
These various stages can be implemented with radio frequency (“RF”) amplifier parts designed for high performance and low cost for millimeter wave bands, including 28 GHz and 60 GHz. Using such an active signal processing architecture, requirements on array antennas and their associated mechanical supporting devices are relaxed and simplified. In certain circumstances, for example, for deployments in remote windy sites, array antennas with compact form factors could be more advantageous to employ than a larger array antenna. In considering the installation, maintenance, and system reliability, the proposed solutions employing compact array antennas would be preferable over the use of large array antennas.
As modularity is another feature that the example implementation addresses with considerations in system architecture, the proposed system configurations are based on semi-opened modules, separating the receive and transmit antennas, thereby allowing the insertion of filtering, frequency conversion, and digital signal generation and processing. The proposed modular subsystems are provided with interfaces for a digital control and bus with register access, an autonomous power supply, and possibly wireless modules with remote connectivity for system configuration, calibration, monitoring, and updating.
In particular, another example implementation is to split the active relay architecture into two separate functionalities, which are provided by a separate receive architecture and transmit architecture, as is shown in
In other system configurations, beam steering can be supported and the proposed solutions consist of phase shifters and feed networks in the front-end configurations. One of the proposed features is automatic gain control (“AGC”) capability based on assessments of the link status, such as, for example, received signal strength indicator (“RSSI”) or more collaborated system procedures including link quality monitoring and control functions. The AGC function is also separated and distributed to separate transmit and receive sections, so that the FWD link and RTN links are controlled and maintained independently.
Attention is now directed to
Another example active relay circuit implementation is illustrated in
The active relay architectures described herein may be applied to various use cases with various system level solutions. Example solutions may include the feature of partial power combining and dividing (for beamforming and steering) that supports active relay solutions based on subarray configurations, active power bootstrapping with separate reflect array (“RA”) antennas, active relay solutions for both frequency division duplexing (“FDD”) and TDD operations, and many others. An example solution is illustrated in
Another example supported by the active relay architecture 900 is for high gain applications using phased arrays, where the number of elements can be very large. For these applications, a “one-element-one-PA” configuration could be very difficult to implement and, in addition, the DC power consumption could be prohibitive. In cases where the phases at all of the elements are aligned, the signals received at various elements can be combined with power combiners. Once the signals are amplified by the PAs by the active relay sections 902, these amplified signals can be combined, divided, and redistributed for transmission. The active relay architecture 900 is scalable and adaptable to both variable and fixed scenarios for the phase alignments between the two independent receive and transmit phased arrays. A particular feature of the active relay architecture 900 is that it supports from one beam up to M number of beams, and the transmit beamforming operations are realized in space. Almost any 5G relay scenario can be supported with this universal architecture configuration for highly flexible and active relay solutions with trade-offs performed between antenna cost and coverage performance.
It is appreciated that the previous description of the disclosed examples is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these examples will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other examples without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the examples shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Where methods described above indicate certain events occurring in certain order, those of ordinary skill in the art having the benefit of this disclosure would recognize that the ordering may be modified and that such modifications are in accordance with the variations of the present disclosure. Additionally, parts of methods may be performed concurrently in a parallel process when possible, as well as performed sequentially. In addition, more steps or less steps of the methods may be performed. Accordingly, examples are intended to exemplify alternatives, modifications, and equivalents that may fall within the scope of the claims.