WO2024149566A1

WO2024149566A1 - Methods for determining a phase configuration at a coverage enhancing device, a related network node and a related coverage enhancing device controlling node

Info

Publication number: WO2024149566A1
Application number: PCT/EP2023/086040
Authority: WO
Inventors: Fredrik RUSEK; Erik Lennart Bengtsson
Original assignee: Sony Europe BV United Kingdom Branch; Sony Group Corp
Current assignee: Sony Europe BV United Kingdom Branch; Sony Group Corp
Priority date: 2023-01-10
Filing date: 2023-12-15
Publication date: 2024-07-18
Anticipated expiration: 2025-07-10
Also published as: EP4649595A1

Abstract

Disclosed is a method, performed in a coverage enhancing device, CED, for determining an index modulation at the CED. The index modulation is used for conveying information between a transmitter node and a receiver node. The method comprises obtaining a phase parameter associated with an antenna element of the CED and more than one receive antenna of the receiver node. The method comprises obtaining a phase configuration at one or more antenna elements of the CED. The phase configuration is based on the phase parameter. At least one antenna element of the CED is associated with more than one receive antenna element at the receiver node.

Description

METHODS FOR DETERMINING A PHASE CONFIGURATION AT A COVERAGE

ENHANCING DEVICE, A RELATED NETWORK NODE AND A RELATED COVERAGE

ENHANCING DEVICE CONTROLLING NODE

The present disclosure pertains to the field of wireless communications. The present disclosure relates to methods for determining an index modulation at a coverage enhancing device (CED), a related network node and a related CED controlling node.

BACKGROUND

Coverage enhancing devices (CEDs), such as smart repeaters and reflective intelligent surfaces (RISs), can provide coverage enhancement for wireless devices in wireless telecommunication systems. Coverage enhancing devices can make use of array gain when retransmitting, such as reflecting, signals from a transmitter node to a receiver node. CEDs can be used to improve signal coverage, for example at hard-to-reach locations, or transitions from outdoors to indoors. Certain coverage enhancing devices can be reconfigurable, such as having the ability to choose a phase shift per coverage enhancing unit cell, such as per antenna element. By applying a phase shift, such as changing the phase, a change of direction of an outgoing signal can be applied. The phase shift, such as phase angles, can be configured to obtain desired incoming and/or outgoing angles of a signal. Typically, the CED retransmits the signal received from the transmitter node in order to reach receiver nodes located out of coverage of the transmitter node using the frequency bandwidth of the signal received by the CED from the transmitter node.

There are several modulation schemes available for determining a reflecting pattern to be used at the CED for retransmitting information from the transmitter node to the receiver node. However, these reflecting patterns have the drawback that they induce a power loss to the channel from the CED to a receiver antenna at the receiver node compared to focusing all the transmit power of the CED towards one single receive antenna. SUMMARY

Accordingly, there is a need for devices and methods for determining a modulation at the CED, which may mitigate, alleviate or address the shortcomings existing and may provide an improved power efficiency of the CED.

Disclosed is a method, performed in a coverage enhancing device, CED, for enabling a determination of a phase configuration at the CED. The phase configuration is used for conveying information between a transmitter node and a receiver node. The method comprises obtaining a phase parameter associated with an antenna element of the CED and more than one receive antenna of the receiver node. The method comprises obtaining a phase configuration at one or more antenna elements of the CED. The phase configuration is based on the phase parameter. At least one antenna element of the CED is associated with more than one receive antenna element at the receiver node.

Further, a CED comprising memory circuitry, processor circuitry, and a wireless interface is provided. The CED is configured to perform any of the methods disclosed herein.

It is an advantage of the present disclosure that the power efficiency of the CED can be improved while increasing performance of the network. The power for each channel from the CED to the receive antennas of the receiver node can be increased compared to known reflecting patterns, such as reflecting patterns using a sub-array approach. By the CED determining a phase configuration for associating one antenna element of the CED to more than one receive antenna at the receiver node, a beam splitting algorithm can be applied which provides higher received power at the receiver node than using a subset of the available antenna elements of the CED for each channel from the CED to the receive antennas of the receiver node can be increased compared to known reflecting patterns. Thereby, the efficiency, such as the gain, of the CED can be increased, for example when employing index modulation for determining a channel between the CED and the receiver node.

Disclosed is a method, performed in a coverage enhancing device, CED, controlling node, for determining a phase configuration at a CED. The phase configuration is used for conveying information between a transmitter node and a receiver node. The method comprises obtaining a phase parameter associated with an antenna element of the CED and more than one receive antenna of the receiver node. The method comprises determining a phase configuration at one or more antenna elements of the CED. The phase configuration is based on the phase parameter. The phase configuration associates at least one antenna element of the CED with more than one receive antenna element at the receiver node.

Further, a CED controlling node comprising memory circuitry, processor circuitry, and a wireless interface is provided. The CED controlling node is configured to perform any of the methods disclosed herein.

It is an advantage of the present disclosure that the CED controlling node can enable an improved power efficiency at the CED by determining a phase configuration for associating one antenna element of the CED to more than one receive antenna at the receiver node, while increasing performance of the network. The determined phase configuration enables the CED to apply a beam splitting algorithm which provides higher received power at the receiver node than known reflecting patterns, using a subset of the available antenna elements of the CED for each channel from the CED to the receive antennas of the receiver node. Thereby, the power for each channel from the CED to the receive antennas of the receiver node can be increased compared to known reflecting patterns. Thereby, the efficiency, such as the gain, of the CED can be increased, for example when employing index modulation for determining a channel between the CED and the receiver node.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present disclosure will become readily apparent to those skilled in the art by the following detailed description of examples thereof with reference to the attached drawings, in which:

Fig. 1 is a diagram illustrating an example wireless communication system comprising an example core network node, an example radio network node, an example wireless device, and an example coverage enhancing device according to this disclosure,

Figs. 2A-2C are diagrams illustrating a first example communication between an example CED, an example CED controlling node and an example wireless device according to this disclosure, Figs. 3A-3D are diagrams illustrating a second example communication between an example CED, an example CED controlling node and an example wireless device according to this disclosure

Fig. 4 is a flow-chart illustrating an example method, performed by a coverage enhancing device, CED, for enabling determination of a phase configuration at the CED according to this disclosure,

Fig. 5 is a flow-chart illustrating an example method, performed by a CED controlling node, for determining a phase configuration at the CED, according to this disclosure,

Fig. 6 is a block diagram illustrating an example CED according to this disclosure, and

Fig. 7 is a block diagram illustrating an example CED controlling node according to this disclosure.

DETAILED DESCRIPTION

Various examples and details are described hereinafter, with reference to the figures when relevant. It should be noted that the figures may or may not be drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the examples. They are not intended as an exhaustive description of the disclosure or as a limitation on the scope of the disclosure. In addition, an illustrated example needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular example is not necessarily limited to that example and can be practiced in any other examples even if not so illustrated, or if not so explicitly described.

The figures are schematic and simplified for clarity, and they merely show details which aid understanding the disclosure, while other details have been left out. Throughout, the same reference numerals are used for identical or corresponding parts.

Fig. 1 is a diagram illustrating an example wireless communication system 1 according to this disclosure. The wireless communication system 1 comprises a wireless device 300, a radio network node 400 and a core network (CN) node 600. As discussed in detail herein, the present disclosure relates to a wireless communication system 1 comprising a cellular system, for example, a 3GPP wireless communication system.

A radio network node disclosed herein refers to a radio access network (RAN) node operating in the radio access network, such as a base station, an evolved Node B, eNB, gNB in NR, and/or a transmission and reception point (TRP). In one or more examples, the RAN node is a functional unit which may be distributed in several physical units.

The CN node disclosed herein refers to a network node operating in the core network, such as in the Evolved Packet Core Network, EPC, and/or a 5G Core Network, 5GC. Examples of CN nodes in EPC include a Mobility Management Entity, MME.

In one or more examples, the CN node 600 is a functional unit which may be distributed in several physical units.

The wireless communication system 1 described herein may comprise one or more wireless devices 300, and/or one or more radio network nodes 400, such as one or more of a base station, an eNB, a gNB and an access point.

A wireless device 300 may refer to a mobile device and/or a user equipment (UE). The wireless device 300 may be configured to communicate with the network node 400 via a wireless link (or radio access link) 10. The WD 300 may comprise one or more antennas, such as K antennas. A received, discrete-time, signal at antenna k of the WD 300 may herein be referred to as received signal yk.

The wireless communication system 1 may comprise a coverage enhancing device (CED) 800. The CED 800 may be one or more of a smart repeater, such as a Network Controlled Repeater (NCR), a reflective intelligent surface (RIS), an integrated access and backhaul (IAB), and/or another wireless device (WD), such as a WD communicating via sidelink. The CED 800 may provide coverage enhancement for wireless devices. The CED 800 may be controlled, such as may be configurable, by the network node, such as the network node 400 and/or the CN node 600. The CED may be used to improve signal coverage in the wireless communication system 1. The CED 800 may be used to retransmit, such as forward, signals, such as data and/or control signals, between a transmitter node and a receiver node, such as between the radio network node 400 and the WD 300. In uplink (UL) communication the WD 300 is the transmitter node and the radio network node 400 is the receiver node. In downlink (DL) communication the radio network node 400 is the transmitter node and the WD 300 is the receiver node. The retransmission can be advantageous when the WD 300 is located at hard-to-reach locations, such as at a border of a coverage area of the network node 400 and/or when a direct (such as a line-of-sight) link between the network node 400 and the WD 300 is obstructed. The CED 800 may comprise a plurality of antenna elements 800B. Each antenna element 800B of the CED 800 that can be configured with a respective phase shift, for example by means of a phase configuration. By controlling the phase shifts, such as jointly or separately controlling the phase shifts, an incoming and/or outgoing angle of a signal received and/or transmitted by the CED 800 can be controlled and/or adapted. In one or more example methods, the angle of incoming and outgoing signals can be controlled by controlling the relative phase between respective antenna elements 800B of the CED 800. The phase shift may be a capacitor-based phase shift and/or a true time delay line, such as a time domain shift, between antenna elements of the CED 800. The WD 300 may be configured to communicate with the network node 400 directly via the wireless link (or radio access link) 10 and/or via the CED 800 via wireless link 10A. The wireless link 10A may herein be referred to as a reflected, such as retransmitted, wireless link. The CED 800 may be controlled by one or more network nodes, such as the radio network node 400, or one or more wireless devices, such as the WD 300. The one or more network nodes or wireless devices controlling the CED 800 may herein be referred to as coverage enhancing device controlling nodes. In one or more example methods, the coverage enhancing device controlling node can be a CN node, such as the CN node 600 in Fig 1 . In one or more example methods, the coverage enhancing device controlling node can be a node in an external network that can access the CED 800, for example through the internet via a gateway function. The CED 800 may comprise one or more of a controller 800A, a first antenna element 800BA, and a second antenna element 800BB. Herein, the terms antenna and antenna element are used interchangeably.

There are many modulation formats available for transmitting information from the transmitter node, such as the radio network node 400, via the CED 800, to the receiver node, such as the WD 300. One such method is index modulation. Index modulation can take different forms. A straightforward approach would be to associate different sub-parts, such as sub-arrays of antenna elements, of the CED with different receive antennas, in such a way that only a subset of the receive antennas at the receiver node will receive substantial power. The exact subset of the receive antennas that will receive the substantial power may be indicated as a part of an information transfer between the CED 800 and the receiver node. For example, for a K antenna receiver node, the cardinality of the aforementioned subset may be unity. In other words, only one receive antenna out of the K antennas of the receiver node may be configured to receive the substantial power. If the CED 800 redirects the signal to one receive antenna only, three bits can be transmitted to the receiver node. The receiver node may decode these three bits by detecting which of the plurality of antennas that receives the signal, such as the substantial power. The index 1-K of the antenna that receives the signal, such as the substantial power, is used for modulating subsequent signaling between the CED 800 and the receiver node.

The CED 800 can be configured to reflect signals from the transmitter node to more than one antenna of the receiver node simultaneously, such as to two receive antennas k and k₂ at the receiver node. In known CED systems, the CED 800 can be configured to reflect signals to more than one receive antenna of the receiver node by (abstractly) splitting the N antenna elements at the CED 800 into sub-arrays, where each sub-array is configured to retransmit the signal to a respective receive antenna at the receiver node. Each sub-array can comprise a subset of the antenna elements of the CED. The sub-array of the CED may be configured with respective phase configuration for retransmitting the signal to the respective receive antenna of the receiver node.

According to this disclosure, a beam-splitting algorithm is applied to one or more of the antenna elements of the CED, so that one antenna element of the CED retransmits the signal to more than one receive antenna of the receiver node. In other words, instead of using a subset, such as a sub array, of the antenna elements of the CED for each channel from the CED to the receiver node, each respective antenna element of the CED can be used for transmitting to more than one of the receive antennas of the receiver node.

The sub-array approach reduces the effective aperture, such as halves the effective aperture when the antenna elements are split into two sub-arrays. The aperture can herein be seen as the size of the array, such as the number of antenna elements comprised in the array. The effective aperture can thus be seen as the effective (physical) size of the antenna, such as each sub-array of antenna elements. For the sub-array approach the area of each sub-array defines the effective aperture, while applying the beam-splitting algorithm allows all antenna elements to contribute to each beam, such as to the signal transmission over each channel between the CED and the receive antennas of the receiver node. Applying the beam-splitting algorithm thus allows the aperture to become the full array, such as all of the antenna elements of the CED. The remaining power for each channel then reduces to a quarter, which corresponds to a 6 dB reduction in received power compared to letting all antenna elements of the CED target, such as transmit to, the same receive antenna at the receiver node. By applying the beam-splitting algorithm, the full aperture can be used for each channel from the CED 800 to the receiver node, since all of the antenna elements of the CED can contribute to each channel between the CED and the more than one receive antennas at the receiver node. Using beam splitting at the antenna elements of the CED 800 leads to a power loss of 3 dB due to the inherent power split and another 1 dB due to phase-only beamforming at the respective antenna element of the CED 800. This is not trivial to observe and holds as the CED grows large, such as when the number of elements increases. Therefore, the solution according to this disclosure results in 2 dB superior performance, such as 2 dB superior performance in terms of Signal-to-Noise ratio (SNR), compared to the sub-array approach currently used, (3+1 dB power loss instead of 6 dB). Power loss herein refers to the power loss per receive antenna compared to focusing the entire signal, such as the entire transmit power, to a single receive antenna.

For higher subset-cardinality systems the gain is even larger, for example cardinality 4 reduces the available power at each receive antenna by 12 dB for the sub-array approach, while the beam splitting according to the current disclosure yields a loss of only 7dB, such as a 5 dB gain compared with sub-arrays. Furthermore, applying the beam splitting algorithm can yield identically strong signals at the targeted receive antennas as the subarray approach.

According to the current disclosure, the phase configuration of the antenna elements of the CED can be determined according to the equation Eq. 1 below.

In Eq. 1 , the value 9_k>i denotes a phase of a composite channel from the transmitter node, such as from a radio network node in DL, to the k :th receive antenna of the receiver node, such as of a WD in DL, via the i :th antenna element of the CED. Further, the parameters d_Q and dj are information symbols, that can be used for generating a constellation, such as one or more of a quadrature phase-shift keying (QPSK) constellation, an 8 phase-shift keying (PSK) constellation, a 16PSK constellation, and any other suitable constellation. The phase 9_{k i} of the composite channel can be determined based on index modulation as described in detail in relation to Figs. 2A-3D. The phase configuration may be indicative of a power distribution associated with, such as a power distribution of, the respective antenna elements of the CED.

Figs. 2A-2C are diagrams illustrating a first example communication between an example CED, an example CED controlling node and an example wireless device according to this disclosure. Figs. 2A-2C illustrates a scenario where a CED (such as CED 800 of Fig. 1 ) is assisted by a CED controlling node (such as CED controlling node 400 of Fig. 1 ) for determining a phase configuration, such as a phase parameter of the phase configuration, of the CED. The phase configuration, such as the phase parameter, may be determined using index modulation.

The CED 800 comprises N antenna elements and the wireless device 300 comprises K receive antenna elements. The received signals at the receive antennas k=1 K of the wireless device 300 can herein be denoted as y₁₍ ... ,y_K.

The wireless device 300 may determine (such as, learn) a phase parameter associated with an antenna element of the CED 800 and more than one receive antenna of the wireless device 300 at respective time instants (such as at a time t with t = 1,

The phase parameter being associated with an antenna element of the CED 800 and more than one receive antenna of the wireless device 300 can herein be seen as the phase parameter being part of, such as contributing to, the transmission of the signal to the receive antenna element.

The wireless device 300 may determine the phase parameter based on a received reference signal y₁₍ - ,y_K at the antenna elements k = 1, ... , K of the wireless device 300 via a respective antenna element 800B of the CED 800 at a respective time instant (such as at time t with t = 1,

The reference signal 504A, 504B, 504C reflected by the CED may originate from the CED controlling node 400. Upon the respective reference signals 504A, 504B, 504C being received by the respective receive antennas k=1 K of the wireless device 300, the respective received signal may be referred to as received signals y₁₍ - ,y_K.

The wireless device 300 may determine a first set of phase parameters (such as phase parameters 9_1:1, 0₂,i> - , 9_K,i of Equation (Eq. 1 )) associated with a first antenna element 800BA of the CED 800 and a plurality of antennas elements of the wireless device 300 (such as antenna elements k = 1, ... , K ) at a first time instant t = 1 (as illustrated in Fig. 2A). The CED At a second time instant time instant t = 2, the wireless device 300 may determine a second set of phase parameters (such as phase parameters 0_{1 2}, 9_{2 2}, - , 9K, 2 of Equation (Eq. 1 )) associated with a second antenna element 800BB of the CED 800 and a plurality of the antenna elements of the wireless device 300 at a second (as illustrated in Fig. 2B). In one or more examples herein, the wireless device may proceed with determining sets of phase parameters for each antenna element of the CED and the plurality of antenna elements of the wireless device at respective time instants. At a time instant t = N the wireless device 300 may determine an N:th set of phase parameters (such as phase parameters 9_{1 N}, 9_{2 N}, - , 9_{K N} of Equation (Eq. 1 )) associated with a last antenna element N (such as, denoted as 800BN) of the CED 800 and a plurality of antenna elements of the wireless device 300 at time instant t = TV (as illustrated in Fig. 2C).

The wireless device 300 may transmit (such as feedback) the phase parameters (such as, 9_k>i of Equation (Eq. 1 ), with k = 1, ... , K and i = 1, ... , TV) to the CED controlling node 400 either via the CED 800 or via a direct wireless link 506.

The CED controlling node 400 and/or a second network node may determine, based on the phase parameter, a phase configuration associated with the one or more antenna elements of the CED 800 (such as, c_t of Equation (Eq. 1 ), with 1 < i < TV).

The CED controlling node 400 may transmit the phase configuration to the CED 800.

The CED 800 may retransmit, based on the phase configuration, a signal from the CED controlling node 400 and/or a second network node to the wireless device 300. When the retransmitted signal is transmitted in DL, the wireless device 300 is referred to as a receiver node, as the wireless device 300 receives the signal from a transmitter node, such as the CED controlling node 400 and/or the second network node. Prior to the phase configuration being determined, the receiver node may be instructed to transmit control signalling, such as reference signals, for determining the phase parameter to be used in the phase configuration of the CED 800.

Figs. 3A-3D are diagrams illustrating a second example communication between an example CED, an example CED controlling node and an example wireless device according to this disclosure. Figs. 3A-3D illustrates a scenario where the CED 800 is configured to determine a phase configuration to be used by the CED 800 for conveying information between a transmitter node and a receiver node. The determination of the phase configuration may be based on an index modulation.

The CED 800 may, at an initial time instant t = 0, receive, from the CED controlling node 400, information indicative of a channel 702A associated with each antenna of the plurality of N antennas comprised in the CED 800 and each antenna comprised in the CED controlling node 400 (as illustrated in Fig. 3A). In other words, the CED 800 may learn the channel 702A between the CED 800 and the CED controlling node 400. The information indicative of the channel may comprise a channel quality, and/or a power distribution of the channel 702A.

The wireless device 300 may transmit reference signals y₁₍ ... , y_K using a respective antenna element k = 1, ... , K at a respective time instant t with t = 0,

The CED 800 may measure a phase parameter associated with one or more antenna elements of the CED 800 and the respective receive antenna of the wireless device 300 at the respective time instant t. The CED 800 may obtain, such as measure, the phase parameter based on the reference signal received from each of the antenna elements of the wireless device 300. In one or more example methods, the CED 800 may determine the phase parameter based on the information indicative of the channel 702A received from the CED controlling node 400.

As shown in Fig. 3B, the CED 800 can measure, based on a reference signal y received from the first antenna element k = 1 of the wireless device 300, a first set of phase parameters (such as phase parameters 0_ltl, 0_1>2, - , 0_1>N of Equation (Eq. 1 )) associated with each antenna element of the CED 800 at a first time instant t = 1.

As shown in Fig. 3C, the CED 800 can measure, based on a reference signal y₂received from the second antenna element k = 2 of the wireless device 300, a second set of phase parameters (such as phase parameters 0_2jl, 0₂,₂, ■■■, 0₂, N of Equation (Eq. 1 )) associated with each antenna element of the CED 800 at a second time instant t = 2.

As shown in Fig. 3D, the CED 800 can measure, based on a reference signal y_K received from the last antenna element k = K of the wireless device 300, a K:th set of phase parameters (such as phase parameters 0_kil, 0_ki2, - , 0_K,N of Equation (Eq. 1)) associated with each antenna element of the CED 800 at a time instant t = K.

The CED 800 may transmit, such as feedback, to the CED controlling node, the obtained phase parameters, such as sets of phase parameters. The CED controlling node 400 may determine, based on the phase parameters, a phase configuration at the one or more antenna elements, such as receive antennas, of the CED 800 (such as, of Equation (Eq. 1 ), with 1 < i < N). The phase configuration may associate one antenna element of the CED 800 with more than one antenna element, such as one or more receive antennas, of the wireless device 300. Associate one antenna element of the CED 800 with more than one antenna element of the wireless device 300 can herein be seen as the phase configuration configuring the one antenna element of the CED 800 to contribute to the signal toward the more than one antenna element of the wireless device 300. In other words, once the antenna element of the wireless device is associated with the more than one antennal element of the wireless device 300, the antenna element of the CED is configured to contribute to a signal transmission from the CED towards the more than one antenna elements of the wireless device. In one or more example methods, the phase configuration may associate a plurality of respective antenna elements of the CED 800 with more than one antenna element of the wireless device 300. In other words, in one or more example methods, the phase configuration configures a plurality of respective antenna element of the CED 800 to contribute to the signal toward the more than one antenna element of the wireless device 300. In one or more example methods, the phase configuration may associate each antenna element of the CED 800 with more than one antenna element of the wireless device 300. In other words, in one or more example methods, the phase configuration configures each antenna element of the CED 800 to contribute to the signal toward the more than one antenna element of the wireless device 300. In other words, the full aperture of the CED may be used for the signal transmission towards the more than one antenna elements of the wireless device. This corresponds to step S104 of method 100 as described in relation to Fig. 4.

In one or more example methods, the CED 800 determines the phase configuration based on the obtained, such as measured, phase parameter. For example, the CED controlling node 400 can transmit, to the CED 800, index modulation related parameters (such as, constellation parameters denoted as m_k, d.Q, di in Equation (Eq. 1 )) associated with the antenna elements of the wireless device 300. The CED 800 can determine the phase configuration based on the index modulation related parameters, such as based on the index modulation related parameters and the obtained phase parameters.

The CED 800 may retransmit a signal from the CED controlling node 400 and/or the second network node to the wireless device 300 based on, such as using, the phase configuration.

Fig. 4 shows a flow-chart illustrating an example method 100, performed by a coverage enhancing device, CED, according to the disclosure, for enabling determination of a phase configuration at the CED. The phase configuration is used for conveying information between a transmitter node and a receiver node. The CED is the CED disclosed herein, such as CED 800 of Fig. 1 , Figs. 2A-2C, Figs. 3A-3D and Fig. 6.

The method 100 comprises obtaining S103 a phase parameter associated with an antenna element of the CED and more than one receive antenna of the receiver node. The phase parameter may be obtained by means of one or more of UL and DL channel measurements between antenna elements of the CED and receive antennas of the receiver node. In one or more example methods, the phase parameter may be obtained using one or more of the index modulation techniques discussed herein in relation to Fig. 2A-3D. Each phase parameter can be seen as a phase parameter for each respective pair of CED antenna elements and receiver node antenna elements, such as for a channel between each CED antenna element and each antenna element of the receiver node. In one or more example methods, obtaining S103 the phase parameter comprises measuring S103A the phase parameter associated with the respective antenna element of the CED, based on a reference signal received from each of the antenna elements of the receiver node, such as of the receiver node of the communication to be transmitted using the phase configuration, respectively. For example, where the communication to be transmitted using the phase configuration is in DL, the receiver node is the WD, and the reference signal may thus be received from the WD. In DL the transmitter node may be a radio network node, and the radio network node may be the CED controlling node. For example, where the communication to be transmitted using the phase configuration is in UL, the receiver node is the radio network node 400, and the reference signal may thus be received from the radio network node 400. Measuring S103A is similar to the signaling described in relation to Figs. 3A-3D, where the reference signal corresponds to the reference signals y₁₍ - ,y_K.

In one or more example methods, obtaining S103 the phase parameter comprises redirecting S103B a reference signal from the transmitter node, such as from the radio network node in DL, to the antenna elements of the receiver node using a plurality of the CED’s antenna elements at respective time instants. In other words, the CED uses one antenna element at a time to redirect the reference signal, such as the reference signals 504A-504C in Figs. 2A-2C. Redirecting S103B is similar to the signaling described in relation to Figs. 2A-3C.

In one or more example methods, obtaining S103 the phase parameter comprises receiving S103C a phase parameter message indicative of the phase parameter based on the redirected reference signal. In one or more example methods, the phase parameter message is received from one or more of the transmitter node and the receiver node, such as from the CED controlling node or the wireless device. In one or more example methods, the phase parameter may be received from the transmitter node, such as from the CED controlling node, based on feedback on the redirected reference signal from the receiver node, such as from the wireless device.

In one or more example methods, such as when the CED has obtained the phase parameter by measuring on the reference signal received from the receiver node, the method 100 comprises sending S104 the obtained phase parameter to one or more of the transmitter node and a CED controlling node. The method 100 comprises obtaining S105 a phase configuration at one or more antenna elements of the CED. The phase configuration is based on the phase parameter. In one or more example methods, the phase configuration associates at least one antenna element of the CED with more than one receive antenna element at the receiver node. Being associated with may herein be seen as contributing to the transmission of the signal to the receive antenna element. In other words, according to one or more example methods of this disclosure, at least one antenna element of the CED is associated with, and contributes to the transmission to, more than one receive antenna element at the receiver node.

In one or more example methods, obtaining S105 the phase configuration comprises receiving S105A the phase configuration from the CED controlling node. In one or more example methods, the CED controlling node may be the transmitter node, such as the node transmitting the signal that is to be reflected by the CED using the phase configuration. This may be the case for DL transmissions. In one or more example methods, the CED controlling node may be a different node than the transmitter node. This may for example be the case for UL transmission, and/or sidelink transmission.

For UL and/or sidelink the wireless device may send reference signals to the CED controlling node, such as a CED controlling node comprised in the CED itself or being separate from the CED. The CED controlling node may obtain channel estimates. The CED controlling node may configure the CED with the phase configuration for reflecting a signal. The wireless device may then transmit the signal towards the CED which is reflected by the CED in UL and/or sidelink based on the phase configuration.

In one or more example methods, obtaining S105 the phase configuration comprises determining S105B the phase configuration based on the obtained phase parameter.

In one or more example methods, the phase configuration corresponds to a power distribution over a set of antenna elements of the receiver node. In one or more example methods, the phase configuration, such as the power distribution, is associated with one or more codewords. The one or more codewords may correspond to a reflected power contribution associated with one or more of the antenna elements comprised in the CED. A set can herein be seen as one or more. In one or more example methods, the phase configuration is associated with one or more codewords.

In one or more example methods, each codeword is indicative of a reflected power contribution from more than 1/K CED antenna elements. K herein indicates the cardinality of the receiver node, such as the number of targeted antenna elements at the receiver node. 1/K can herein be seen as not forming K subsets of antenna elements at the CED for reflecting the signal towards K receive antennas at the receiver node. Instead, one antenna element, such as each antenna element of the CED, is configured for reflecting the signal towards K receive antennas of the receiver node, in contrast to the sub-array approach where K sub-arrays are formed for reflecting the signal towards K receive antennas of the receiver node.

In one or more example methods, the phase configuration is based on a constellation parameter, such as the parameters

in Equation (Eq. 1 )), associated with the antenna elements of the receiver node. The parameters d_Q and d, are information symbols, that can be used for generating a constellation, such as one or more of a QPSK constellation, an 8PSK constellation, a 16PSK constellation, and any other suitable constellation. In one or more example methods, d_Q and d_I e {0, 1}.

In one or more example methods, the method 100 comprises redirecting S107 a signal from the transmitter node, such as from the CED controlling node and/or a second network node, to the receiver node, such as to the wireless device, using the phase configuration.

Fig. 5 shows a flow-chart illustrating an example method 200, performed by a coverage enhancing device, CED, controlling node according to the disclosure, for determining a phase configuration at the CED. The phase configuration is used for conveying information between a transmitter node and a receiver node. The CED controlling node is the CED controlling node disclosed herein, such as CED controlling node 400 of Fig. 1 , Figs. 2A-2C, Figs. 3A-3D and Fig. 7. The method 200 comprises obtaining S203 a phase parameter associated with an antenna element of the CED and more than one receive antenna of the receiver node. In one or more example methods, obtaining S203 the phase parameter comprises receiving S203A the phase parameter from one or more of the receiver node and the CED. In other words, the CED controlling node may obtain the phase parameter from the receiver node either via the CED and/or via a direct wireless link (such as a wireless link between the receiver node and the CED controlling node). This corresponds to S104 of Fig. 4.

The method 200 comprises determining S207 a phase configuration at one or more antenna elements of the CED. The phase configuration may be determined based on the phase parameter, such as based on the obtained phase parameter. The phase configuration associates at least one antenna element of the CED with more than one receive antenna element at the receiver node. This corresponds to S105A of Fig. 4.

In one or more example methods, the method 200 comprises sending S209 the phase configuration to the CED, to be used for conveying information between the transmitter node and the receiver node.

Fig. 6 shows a block diagram of an example coverage enhancing device, CED, 800 according to the disclosure. The CED 800 comprises memory circuitry 801 , processor circuitry 802, and a wireless interface 803. The CED 800 may be configured to perform any of the methods disclosed in Fig. 4. In other words, the CED 400 may be configured for enabling determination of a phase configuration at the CED 800. The phase configuration may be used for conveying information between a transmitter node and a receiver node.

The CED 800 is configured to communicate with the transmitter node (such as, a network node and/or a CED controlling node) and/or the receiver node (such as, a wireless device and/or a user equipment).

The wireless interface 803 is configured for wireless communications via a wireless communication system, such as a 3GPP system, such as a 3GPP system supporting one or more of: New Radio, NR, Long Term Evolution, LTE, Narrow-band loT, NB-loT, and Long Term Evolution - enhanced Machine Type Communication, LTE-M, and 3GPP system operated in licensed bands or unlicensed bands. The CED 800 is configured to obtain (such as, via the wireless interface 803) a phase parameter associated with an antenna element of the CED and more than one receive antenna of the receiver node.

The CED 800 is configured to obtain (such as, via the wireless interface 803 and/or the processor circuitry 802) a phase configuration at one or more antenna elements of the CED. The phase configuration is based on the phase parameter.

At least one antenna element of the CED 800 is associated with more than one receive antenna element at the receiver node.

Processor circuitry 802 is optionally configured to perform any of the operations disclosed in Fig. 4 (such as any one or more of S103, S103A, S103B, S103C, S104, S105, S105A, S105B, S107). The operations of the CED 800 may be embodied in the form of executable logic routines (for example, lines of code, software programs, etc.) that are stored on a non-transitory computer readable medium (for example, memory circuitry 801 ) and are executed by processor circuitry 802.

Furthermore, the operations of the CED 800 may be considered a method that the CED 800 is configured to carry out. Also, while the described functions and operations may be implemented in software, such functionality may also be carried out via dedicated hardware or firmware, or some combination of hardware, firmware and/or software.

Memory circuitry 801 may be one or more of: a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, a random access memory (RAM), and any other suitable device. In a typical arrangement, memory circuitry 801 may include a non-volatile memory for long term data storage and a volatile memory that functions as system memory for processor circuitry 802. Memory circuitry 801 may exchange data with processor circuitry 802 over a data bus. Control lines and an address bus between memory circuitry 801 and processor circuitry 802 also may be present (not shown in Fig. 6). Memory circuitry 801 is considered a non-transitory computer readable medium.

Memory circuitry 801 may be configured to store the phase parameter, the phase configuration in a part of the memory. Fig. 7 shows a block diagram of an example CED controlling node 400 according to the disclosure. The CED controlling node 400 comprises memory circuitry 401 , processor circuitry 402, and a wireless interface 403. The CED controlling node 400 may be configured to perform any of the methods disclosed in Fig. 5. In other words, the CED controlling node 400 may be configured for enabling determination of a phase configuration at a CED. The phase configuration may be used for conveying information between a transmitter node and a receiver node. The CED controlling node 400 may be configured to assist (such as, support) the CED to determine the phase configuration.

The CED 800 is configured to communicate with the transmitter node and/or the receiver node. The transmitter node may be seen as a network node and/or a CED controlling node. The receiver node may be seen as a wireless device, such as a user equipment.

The CED controlling node 400 is configured to communicate with the transmitter node (such as, a network node) and/or the receiver node (such as, a wireless device and/or a user equipment). The CED controlling node 400 may be seen as a receiver node.

The CED controlling node 400 is configured to obtain (such as, via the wireless interface 403) a phase parameter associated with an antenna element of the CED and more than one receive antenna of the receiver node.

The CED controlling node 400 is configured to determine (such as, via the processor circuitry 402) a phase configuration at one or more antenna elements of the CED. The phase configuration is based on the phase parameter.

The phase configuration associates at least one antenna element of the CED with more than one receive antenna element at the receiver node.

The wireless interface 403 is configured for wireless communications via a wireless communication system, such as a 3GPP system, such as a 3GPP system supporting one or more of: New Radio, NR, Long Term Evolution, LTE, Narrow-band loT, NB-loT, and Long Term Evolution - enhanced Machine Type Communication, LTE-M, and 3GPP system operated in licensed bands or unlicensed bands.

The CED controlling node 400 is optionally configured to perform any of the operations disclosed in Fig. 5 (such as any one or more of S203, S203A, S207, S209). The operations of the CED controlling node 400 may be embodied in the form of executable logic routines (for example, lines of code, software programs, etc.) that are stored on a non-transitory computer readable medium (for example, memory circuitry 401 ) and are executed by processor circuitry 402.

Furthermore, the operations of the CED controlling node 400 may be considered a method that the CED controlling node 400 is configured to carry out. Also, while the described functions and operations may be implemented in software, such functionality may also be carried out via dedicated hardware or firmware, or some combination of hardware, firmware and/or software.

Memory circuitry 401 may be one or more of: a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, a random access memory (RAM), or any other suitable device. In a typical arrangement, memory circuitry 401 may include a non-volatile memory for long term data storage and a volatile memory that functions as system memory for processor circuitry 402. Memory circuitry 401 may exchange data with processor circuitry 402 over a data bus. Control lines and an address bus between memory circuitry 401 and processor circuitry 402 also may be present (not shown in Fig. 7). Memory circuitry 401 is considered a non-transitory computer readable medium.

Memory circuitry 401 may be configured to store the phase parameter, the phase configuration in a part of the memory.

Examples of methods and products (CED and CED controlling node) according to the disclosure are set out in the following items:

Item 1 . A method, performed in a network node comprising a coverage enhancing device, CED, for enabling determination of a phase configuration at the CED, wherein the phase configuration is used for conveying information between a transmitter node and a receiver node, the method comprising: obtaining (S103) a phase parameter associated with an antenna element of the

CED and more than one receive antenna of the receiver node, and obtaining (S105) a phase configuration at one or more antenna elements of the CED, wherein the phase configuration is based on the phase parameter, wherein at least one antenna element of the CED is associated with more than one receive antenna element at the receiver node.

Item 2. The method according to item 1 , wherein obtaining (S103) the phase parameter comprises: measuring (S103A) the phase parameter associated with the respective antenna element of the CED, based on a reference signal received from each of the antenna elements of the receiver node respectively.

Item 3. The method according to item 1 , wherein obtaining (S103) the phase parameter comprises: redirecting (S103B) a reference signal from the transmitter node to the antenna elements of the receiver node using a plurality of the CED’s antenna elements at respective time instants, and receiving (S103C) a phase parameter message indicative of the phase parameter based on the redirected reference signal.

Item 4. The method according to item 3, wherein the phase parameter message is received from one or more of the transmitter node and the receiver node.

Item 5. The method according to any one of the previous items, wherein the method comprises sending (S104) the obtained phase parameter to the transmitter node/CED controlling node.

Item 6. The method according to any one of the previous items, wherein obtaining (S105) the phase configuration comprises receiving (S105A) the phase configuration from the transmitter node.

Item 7. The method according to any one of the items 1 to 5, wherein obtaining (S105) the phase configuration comprises determining (S105B) the phase configuration based on the obtained phase parameter. Item 8. The method according to any one of the previous items, wherein the phase configuration is indicative of a power distribution over a set of antenna elements of the receiver node.

Item 9. The method according to item 8, wherein the phase configuration is associated with one or more codewords.

Item 10. The method according to item 9, wherein each codeword is indicative of a reflected power contribution from more than 1/K CED antenna elements, wherein K is the number of antenna elements at the receiver node.

Item 11. The method according to any of the previous items, wherein the phase configuration is based on a constellation parameter associated with the antenna elements of the receiver node.

Item 12. The method according to any one of the previous items, wherein the method comprises: redirecting (S107) a signal from the transmitter node to the receiver node using the phase configuration.

Item 13. The method according to any one of the previous items, wherein the phase parameter is obtained using index modulation between one or more antenna elements of the CED and one or more receive antennas of the receiver node.

Item 14. A method, performed in a coverage enhancing device, CED, controlling node, for determining a phase configuration at a CED, wherein the phase configuration is used for conveying information between a transmitter node and a receiver node, the method comprising: obtaining (S203) a phase parameter associated with an antenna element of the CED and more than one receive antenna of the receiver node, and determining (S207) a phase configuration at one or more antenna elements of the CED, wherein the phase configuration is based on the phase parameter, wherein the phase configuration associates at least one antenna element of the CED with more than one receive antenna element at the receiver node.

Item 15. The method according to item 14, wherein obtaining (S203) the phase parameter comprises receiving (S203A) the phase parameter from one or more of the receiver node and the CED.

Item 16. A coverage enhancing device, CED, comprising memory circuitry, processor circuitry, and a wireless interface, wherein the CED is configured to perform any of the methods according to any of items 1-13.

Item 17. A coverage enhancing device, CED, controlling node comprising memory circuitry, processor circuitry, and a wireless interface, wherein the CED controlling node is configured to perform any of the methods according to any of items 14-15.

The use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not imply any particular order, but are included to identify individual elements. Moreover, the use of the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. does not denote any order or importance, but rather the terms “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used to distinguish one element from another. Note that the words “first”, “second”, “third” and “fourth”, “primary”, “secondary”, “tertiary” etc. are used here and elsewhere for labelling purposes only and are not intended to denote any specific spatial or temporal ordering. Furthermore, the labelling of a first element does not imply the presence of a second element and vice versa.

It may be appreciated that Figures 1-7 comprise some circuitries or operations which are illustrated with a solid line and some circuitries, components, features, or operations which are illustrated with a dashed line. Circuitries or operations which are comprised in a solid line are circuitries, components, features or operations which are comprised in the broadest example. Circuitries, components, features, or operations which are comprised in a dashed line are examples which may be comprised in, or a part of, or are further circuitries, components, features, or operations which may be taken in addition to circuitries, components, features, or operations of the solid line examples. It should be appreciated that these operations need not be performed in order presented. Furthermore, it should be appreciated that not all of the operations need to be performed. The example operations may be performed in any order and in any combination. It should be appreciated that these operations need not be performed in order presented.

Circuitries, components, features, or operations which are comprised in a dashed line may be considered optional.

Other operations that are not described herein can be incorporated in the example operations. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations.

Certain features discussed above as separate implementations can also be implemented in combination as a single implementation. Conversely, features described as a single implementation can also be implemented in multiple implementations separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as any subcombination or variation of any sub-combination

It is to be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed.

It is to be noted that the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements.

It should further be noted that any reference signs do not limit the scope of the claims, that the examples may be implemented at least in part by means of both hardware and software, and that several "means", "units" or "devices" may be represented by the same item of hardware.

The various example methods, devices, nodes and systems described herein are described in the general context of method steps or processes, which may be implemented in one aspect by a computer program product, embodied in a computer- readable medium, including computer-executable instructions, such as program code, executed by computers in networked environments. A computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory (ROM), Random Access Memory (RAM), compact discs (CDs), digital versatile discs (DVD), etc. Generally, program circuitries may include routines, programs, objects, components, data structures, etc. that perform specified tasks or implement specific abstract data types. Computer-executable instructions, associated data structures, and program circuitries represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

Although features have been shown and described, it will be understood that they are not intended to limit the claimed disclosure, and it will be made obvious to those skilled in the art that various changes and modifications may be made without departing from the scope of the claimed disclosure. The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense. The claimed disclosure is intended to cover all alternatives, modifications, and equivalents.

Claims

1 . A method, performed in a coverage enhancing device, CED, for enabling determination of a phase configuration at the CED, wherein the phase configuration is used for conveying information between a transmitter node and a receiver node, the method comprising: obtaining (S103) a phase parameter associated with an antenna element of the CED and more than one receive antenna of the receiver node, and obtaining (S105) a phase configuration at one or more antenna elements of the CED, wherein the phase configuration is based on the phase parameter, wherein at least one antenna element of the CED is associated with more than one receive antenna element at the receiver node.

2. The method according to claim 1 , wherein obtaining (S103) the phase parameter comprises: measuring (S103A) the phase parameter associated with the respective antenna element of the CED, based on a reference signal received from each of the antenna elements of the receiver node respectively.

3. The method according to claim 1 , wherein obtaining (S103) the phase parameter comprises: redirecting (S103B) a reference signal from the transmitter node to the antenna elements of the receiver node using a plurality of the CED’s antenna elements at respective time instants, and receiving (S103C) a phase parameter message indicative of the phase parameter based on the redirected reference signal.

4. The method according to claim 3, wherein the phase parameter message is received from one or more of the transmitter node and the receiver node.

5. The method according to any one of the previous claims, wherein the method comprises sending (S104) the obtained phase parameter to the transmitter node/CED controlling node.

6. The method according to any one of the previous claims, wherein obtaining (S105) the phase configuration comprises receiving (S105A) the phase configuration from the transmitter node.

7. The method according to any one of the claims 1 to 5, wherein obtaining (S105) the phase configuration comprises determining (S105B) the phase configuration based on the obtained phase parameter.

8. The method according to any one of the previous claims, wherein the phase configuration is indicative of a power distribution over a set of antenna elements of the receiver node.

9. The method according to claim 8, wherein the phase configuration is associated with one or more codewords.

10. The method according to claim 9, wherein each codeword is indicative of a reflected power contribution from more than 1/K CED antenna elements, wherein K is the number of antenna elements at the receiver node.

11. The method according to any of the previous claims, wherein the phase configuration is based on a constellation parameter associated with the antenna elements of the receiver node.

12. The method according to any one of the previous claims, wherein the method comprises: redirecting (S107) a signal from the transmitter node to the receiver node using the phase configuration.

13. The method according to any one of the previous claims, wherein the phase parameter is obtained using index modulation between one or more antenna elements of the CED and one or more receive antennas of the receiver node.

14. A method, performed in a coverage enhancing device, CED, controlling node, for determining a phase configuration at the CED, wherein the phase configuration is used for conveying information between a transmitter node and a receiver node, the method comprising: obtaining (S203) a phase parameter associated with an antenna element of the CED and more than one receive antenna of the receiver node, and determining (S207) a phase configuration at one or more antenna elements of the CED, wherein the phase configuration is based on the phase parameter, wherein the phase configuration associates at least one antenna element of the CED with more than one receive antenna element at the receiver node.

15. The method according to claim 14, wherein obtaining (S203) the phase parameter comprises receiving (S203A) the phase parameter from one or more of the receiver node and the CED.

16. A coverage enhancing device, CED, comprising memory circuitry, processor circuitry, and a wireless interface, wherein the CED is configured to perform any of the methods according to any of claims 1-13.

17. A coverage enhancing device, CED, controlling node comprising memory circuitry, processor circuitry, and a wireless interface, wherein the CED controlling node is configured to perform any of the methods according to any of claims 14-15.