EP4659501A1

EP4659501A1 - A wireless communications device and methods for beam measurement and identification in a multi-beam cell deployment in a wireless communications network

Info

Publication number: EP4659501A1
Application number: EP23702791.7A
Authority: EP
Inventors: Andres Reial; Henrik Sjöland; Gang ZOU; Sina MALEKI
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2023-01-31
Filing date: 2023-01-31
Publication date: 2025-12-10
Also published as: WO2024160355A1

Abstract

A method, performed by a wireless communications device, for beam measurement and identification in a multi-beam cell deployment of a wireless communications network. The wireless communications device comprises a first RF receiver for wireless communication of data or control signals or both within the wireless communications network and a second RF receiver operating at a reduced power consumption compared to a power consumption of the first RF receiver when active. The method comprises: receiving (803), from a network node of the wireless communications network and by the second RF receiver, one or more samples of a broadcasted Reference Signal, RS, associated with a beam; and determining (804) a beam identifier of the beam based on a time-domain correlation of the received one or more samples of the RS with one or more RS hypotheses.

Description

A WIRELESS COMMUNICATIONS DEVICE AND METHODS FOR BEAM MEASUREMENT AND IDENTIFICATION IN A MULTI-BEAM CELL DEPLOYMENT IN A WIRELESS COMMUNICATIONS NETWORK

TECHNICAL FIELD

The embodiments herein relate to a wireless communications device and methods for beam measurement and identification in a multi-beam cell deployment in a wireless communications network. A corresponding computer program and a computer program carrier are also disclosed.

BACKGROUND

In a typical wireless communication network, wireless devices, also known as wireless communication devices, mobile stations, stations (STA) and/or User Equipments (UE), communicate via a Local Area Network such as a Wi-Fi network or a Radio Access Network (RAN) to one or more core networks (CN). The RAN covers a geographical area which is divided into service areas or cell areas. Each service area or cell area may provide radio coverage via a beam or a beam group. Each service area or cell area is typically served by a radio access node such as a radio access node e.g., a Wi-Fi access point or a radio base station (RBS), which in some networks may also be denoted, for example, a NodeB, eNodeB (eNB), or gNB as denoted in 5G. A service area or cell area is a geographical area where radio coverage is provided by the radio access node. The radio access node communicates over an air interface operating on radio frequencies with the wireless device within range of the radio access node.

Specifications for the Evolved Packet System (EPS), also called a Fourth Generation (4G) network, have been completed within the 3rd Generation Partnership Project (3GPP) and this work continues in the coming 3GPP releases, for example to specify a Fifth Generation (5G) network also referred to as 5G New Radio (NR). The EPS comprises the Evolved Universal Terrestrial Radio Access Network (E-UTRAN), also known as the Long Term Evolution (LTE) radio access network, and the Evolved Packet Core (EPC), also known as System Architecture Evolution (SAE) core network. E- UTRAN/LTE is a variant of a 3GPP radio access network wherein the radio access nodes are directly connected to the EPC core network rather than to RNCs used in 3G networks. In general, in E-UTRAN/LTE the functions of a 3G RNC are distributed between the radio access nodes, e.g. eNodeBs in LTE, and the core network. As such, the RAN of an EPS has an essentially “flat” architecture comprising radio access nodes connected directly to one or more core networks, i.e. they are not connected to RNCs. To compensate for that, the E-UTRAN specification defines a direct interface between the radio access nodes, this interface being denoted the X2 interface.

Wireless communication systems in 3GPP

Figure 1 illustrates a simplified wireless communication system. Consider the simplified wireless communication system in Figure 1 , with a UE 12, which communicates with one or multiple access nodes 103-104, which in turn is connected to a network node 106. The access nodes 103-104 are part of the radio access network 10.

For wireless communication systems pursuant to 3GPP Evolved Packet System, (EPS), also referred to as Long Term Evolution, LTE, or 4G, standard specifications, such as specified in 3GPP TS 36.300 and related specifications, the access nodes 103-104 corresponds typically to Evolved NodeBs (eNBs) and the network node 106 corresponds typically to either a Mobility Management Entity (MME) and/or a Serving Gateway (SGW). The eNB is part of the radio access network 10, which in this case is the E-UTRAN (Evolved Universal Terrestrial Radio Access Network), while the MME and SGW are both part of the EPC (Evolved Packet Core network). The eNBs are inter-connected via the X2 interface, and connected to EPC via the S1 interface, more specifically via S1-C to the MME and S1-U to the SGW.

For wireless communication systems pursuant to 3GPP 5G System, 5GS (also referred to as New Radio, NR, or 5G) standard specifications, such as specified in 3GPP TS 38.300 and related specifications, on the other hand, the access nodes 103-104 corresponds typically to an 5G NodeB (gNB) and the network node 106 corresponds typically to either an Access and Mobility Management Function (AMF) and/or a User Plane Function (UPF). The gNB is part of the radio access network 10, which in this case is the NG-RAN (Next Generation Radio Access Network), while the AMF and UPF are both part of the 5G Core Network (5GC). The gNBs are inter-connected via the Xn interface, and connected to 5GC via the NG interface, more specifically via NG-C to the AMF and NG-U to the UPF.

To support fast mobility between NR and LTE and avoid change of core network, LTE eNBs may also be connected to the 5G-CN via NG-U/NG-C and support the Xn interface. An eNB connected to 5GC is called a next generation eNB (ng-eNB) and is considered part of the NG-RAN. LTE connected to 5GC will not be discussed further in this document; however, it should be noted that most of the solutions/features described for LTE and NR in this document also apply to LTE connected to 5GC. In this document, when the term LTE is used without further specification it refers to LTE-EPC.

NR uses Orthogonal Frequency Division Multiplexing (OFDM) with configurable bandwidths and SubCarrier Spacing (SOS) to efficiently support a diverse set of usecases and deployment scenarios. With respect to LTE, NR improves deployment flexibility, user throughputs, latency, and reliability. The throughput performance gains are enabled, in part, by enhanced support for Multi-User Multiple-Input Multiple-Output (MU- MI MO) transmission strategies, where two or more UEs receives data on the same time frequency resources, i.e. , by spatially separated transmissions.

In NR deployments, a cell is identified using one or more, up to 64 in Frequency Range 2 (FR2), Synchronization Signal Block (SSB) beams. An SSB, sometimes also referred to as SS/PBCH Block, occupies 4 OFDM symbols across 240 subcarriers, i.e., 20 Resource Blocks (RBs), and contains three components: Primary Synchronization Signal (PSS) for coarse synchronization and cell group identification, Secondary Synchronization Signal (SSS) for cell identification, and Physical Broadcast Channel (PBCH) for primary System Information (SI) delivery, e.g., delivery of Master Information Block (MIB). When a UE, such as the UE 12, has found the SS Block, e.g., when the UE has detected the synchronization signals and obtained synchronization with the network, it may read the PBCH which contains the MIB. When the MIB has been decoded by the UE, it may start to search for System Information Block (SIB)1. When SIB1 has been found and read, all remaining SIBs may be decoded or requested from the network. PSS and SSS are sequence-based while PBCH is encoded and includes Demodulation Reference Signals (DMRS) for channel estimation to enable decoding of control and data signals. The DMRS may be specific for a specific UE. In general, in sequence-based design, any information is embedded in the choice of a transmitted symbol sequence, where the set of possible sequences has been enumerated previously. The information may be recovered by explicitly checking which sequence in the list of possible sequences was most likely received. In encoding-based design, the information is encoded using a channel encoder and typically the possible set of output sequences may be too large to enumerate explicitly. The information is recovered by applying a matching channel decoder.

Figure 2 illustrates an SSB resource allocation in time and frequency.

SSB is further transmitted in pre-defined bursts across the time domain on configured Physical Resource Blocks (PRBs). The bursts periodicity in terms of time slots depends on which SCS numerology is configured.

A UE assumes that reception occasions of a PBCH, PSS, and SSS are in consecutive symbols and form the SS/PBCH Block.

Figure 3 illustrates how multiple SSB blocks are distributed in time domain for different subcarrier spacings ranging from 15 kHz to 120 kHz, corresponding to Case A, Case B, Case C, Case D and Case E.

Each SSBIock within an SSBIock Set, i.e., all of the SSblocks within a 5 ms period of the SSB transmission corresponding to a half radio frame, is assigned with a unique number starting from 0 and increasing by 1. This number is reset to 0 in the next SS Block Set, i.e., next 5 ms span after the SSB transmission cycle (e.g., 20 ms). Figure 4 illustrates SSB transmissions within two SSB transmission cycles. In Figure 4 there are four beams 41, 42, 43, 44 on which the SSBs are transmitted.

Thus, SS block time locations are indexed from 0 to L-1 in increasing order within a half radio frame, where L is the number of SSBIocks used by the base station.

SS-block time index identifies the SS-block location within an SS burst set. Each SS block has a well-defined position within an SS burst set which is contained within the first or second half of a 5 ms frame. From the SS-block time index, in combination with the half-frame bit, a wireless communications device, such as the UE 12, may determine the frame boundary. The SS-block time index is provided to the UE as two parts: a first part encoded in a scrambling applied to the PBCH and a second part included in the PBCH payload.

Thus, for

• L = 4 o SS block time index are indicated by the 2 Least Significant Bit (LSB) of the 3 bits indicating 8 different PBCH-DMRS sequences. The Most Significant Bit (MSB) is used for half-frame index, i.e. indicating in which half-frame the SSB is transmitted. PBCH DMRS is a special type of physical layer signal which functions as a reference signal for decoding PBCH. As for many other physical layer signals, it is generated by a pseudo random sequence. However, a part which is different for PBCH DMRS is its initialization value, cjnit. The initialization value is made up of various components like Physical Cell ID, SSB Index and Half Frame Number.

That is, by decoding this DMRS the wireless communications device, such as the UE 12, is able to figure out SSB Index and Half Frame. Decoding the DMRS may comprise determining which DMRS sequence was transmitted, e.g by hypothesis testing (e.g., by correlation) with respect to a reference set of possible sequences.

• L = 8 o SS block time index are indicated by 8 different PBCH-DMRS sequences

• L = 64 o LSBs of SS block time index are indicated by 8 different PBCH-DMRS sequences o MSBs of SS block time index are indicated in NR-PBCH payload o 3 bits in NR-PBCH payload may be used for other purposes for frequency ranges below 6 GHz

Usage of NR-PBCH DMRS sequences and explicit bits (for the case of L=64) in NR- PBCH payload to indicate SS block time index follows the following principles:

• MSB bits (b5, ... , b3) for SS block time index in NR-PBCH payload only in case of above 6 GHz

• These 3 bits in below 6 GHz case are used for other purpose (2 reserved bits and 1 MSB bit for SSB-subcarrier-offset)

• 2 or 3 LSB bits of SSB index are indicated by 4 or 8 DMRS sequences

• E.g., for 120 kHz SCS Figure 5 illustrates the indication of SSB time index from 0 to 63, note that each box illustrates a slot, each of which includes 2 SSBs, and 8 DM-RS sequences are transmitted in 4 slots.

The actually transmitted SSBs are indicated in Remaining Minimum System Information (RMSI) both for frequency ranges below 6 GHz and for frequency ranges above 6 GHz. RMSI includes a field which lists which SSB positions in the burst (out of a maximum number of SSBs for a given carrier frequency) are actually transmitted. For example, up to 8 SSBs may be allowed by a specification but the gNB may transmit only the first two: • Below 6 GHz, full bit map is used

• Above 6 GHz, use Group-Bitmap (8 bits) + Bitmap in Group (8 bits)

• Group-Bitmap (8 bits) + Bitmap in Group (8 bits)

• A Group is defined as consecutive SS/PBCH blocks (also referred to as SS blocks in this document), e.g. a sequence of multiple SSB transmissions, typically with different beam configuration applied for each.

• Bitmap in Group may indicate which SS/PBCH block is actually transmitted within a Group, where each Group has the same pattern of SS/PBCH block transmission, and Group-Bitmap may indicate which Group is actually transmitted

• The indication of the actually transmitted SSBs is in compressed form for frequency ranges above 6 GHz. For example, the compressed form may indicate start and end beam indices instead of the explicit bitmap or a full list.

PBCH payload in NR includes both physical layer generated signals and MIB information scheduled from higher layer. Physical layer generated signals include 3 MSB of SS/PBCH block index (or 2 reserved bits for SS/PBCH block index and 1 MSB bit for SSB-subcarrier-offset in FR1), 1 bit half radio frame index, and 4 LSB of System Frame Number (SFN) (4 instead of 3 bits here for byte alignment). The rest of the PBCH payload will be provided by upper layers as MIB with 80 ms Transmisison Time Interval (TTI). PBCH contents include the following information given in the below table:

The number of DMRS sequences and sequence mapping rule is as follows:

> Single long sequence is mapped to all PBCH-DMRS Resource Elements (RE) within an SSB

- PBCH-DMRS sequence is based on long Gold sequence

- Sequence modulation is Quadrature Phase Shift Keying (QPSK)

> LTE PN generator is reused for PBCH DMRS sequence generation, and related parameters are

- Gold Code Linear-Feedback Shift Register (LFSR) size: 31

- Gold Code Polynomials: x31 + x3 + 1 , x31 +x3 + x2 + x + 1 , which are feedforward and feed-back polynomials where the numbers indicate bit positions that are summed (XOR-ed) to create the feed-forward and feed-back signals respectively

> The initialization for PBCH DMRS is:

- c_init = 2¹¹ • (I_SSB + 1) • (L^Vz /4J + 1) + 2⁶ • (I_SSB + 1) + mod( _D, 4)

- For max L=4, f_SSB = I_SSB + 4HF where HF=0 in the first half frame of a radio frame and HF=1 in the second half frame of a radio frame

- For max L=8, and max L=64 f_SSB = I_SSB

Cell-ID-based frequency shift for PBCH-DMRS RE locations is as follows:

- v_shift = /V_I ^c _D ^ellmod4 The initialization value Cinit is made up of various components like Physical Cell ID NID, SSB Index ISSB and Half Frame Number HF. That is, by decoding this DMRS the UE may figure out SSB Index and Half Frame.

In 5G FR2, if SCS=120 kHz then SSB bandwidth is 28.8 MHz and if SCS=240 kHz then SSB bandwidth is 57.6MHz.

In the mm Wave (mmW) frequency range, such as in FR2, the UE needs to perform various supporting tasks to ensure robust operation in the environment when system access signals, system information, link refinement signals, and data transmissions are transmitted in narrow beams. Both SSB and Channel State Information Reference Signal (CSI-RS) signals in mmWave are typically beam-swept over time, meaning that the UE may need to monitor a long reception window to ensure that all possible candidate beams are observed. For best beam identification, the SSB contains a beam ID, i.e. , the SSB index, encoded partially in the PBCH DMRS sequence selection and partially in the PBCH payload.

Since failing to establish or to maintain a robust transmit or receive (TX/RX) beam pair in the DL or in the UL may lead to link failure, the UE needs to perform regular beam detection and beam handling operations during operation, especially in connected mode. For example, the UE needs to perform regular beam detection and beam handling operations when

1. Detecting, verifying, and/or tracking the best SSB beam in the serving cell for coarse spatial orientation and finer-resolution beam group selection

2. Monitoring SSBs from neighbor cells for Radio Resource Management (RRM) for mobility handling

3. Measurement of SSB and/or CSI-RS qualities for DL transmission beam selection.

4. Measurement of SSB and/or CSI-RS qualities for UL transmission beam selection, assuming beam correspondence at the UE.

Detection and measurements related to beam handling in mmW lead to substantial additional activity and awake time of the UE transceiver, in some cases severely reducing energy efficiency and shortening the battery time of the UE.

SUMMARY There is thus a need for a more efficient approach for beam detection and beam handling that avoids long and/or frequent awake times of a transceiver of a wireless communications device, such as the UE 12, while no data transmission is taking place. The transceiver may be a cellular transceiver.

An object of embodiments herein may be to obviate some of the problems related to beam detection mentioned above.

Embodiments herein disclose a UE solution employing a low-power receiver, e.g., for frequent beam handling operations in the absence of data activity, in particular for operations requiring SSB beam detection and beam index identification that conventionally are based on REs in the frequency domain and require a full OFDM receiver and PBCH decoder.

According to a first aspect, the object is achieved by a method, performed by a wireless communications device, for beam measurement and identification in a multibeam cell deployment of a wireless communications network. The wireless communications device comprises a first Radio Frequency, RF, receiver for wireless communication of data or control signals or both within the wireless communications network and a second RF receiver operating at a reduced power consumption compared to a power consumption of the first RF receiver when active.

The method comprises receiving, from a network node of the wireless communications network and by the second RF receiver, one or more samples of a Reference Signal, RS, associated with a beam.

The method further comprises determining a beam identifier of the beam based on a time-domain correlation of the received one or more samples of the RS with one or more RS hypotheses.

The time-domain correlation may be performed with a partial content of the RS, such as with the PBCH-DMRS of an SSB.

According to a second aspect, the object is achieved by a wireless communications device, such as a UE. The wireless communications device is configured to perform the method according to the first aspect above.

According to a further aspect, the object is achieved by a computer program comprising instructions, which when executed by a processor, causes the processor to perform actions according to any of the aspects above. According to a further aspect, the object is achieved by a carrier comprising the computer program of the aspect above, wherein the carrier is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or a computer-readable storage medium.

The above aspects enable a power-efficient approach for beam monitoring and beam management where SSB detection and beam identification is performed without involving the high-power first RF receiver used for wireless communication of data or control signals. This will reduce the power consumption and prolong battery time of the wireless communications device.

BRIEF DESCRIPTION OF THE DRAWINGS

In the figures, features that appear in some embodiments are indicated by dashed lines.

The various aspects of embodiments disclosed herein, including particular features and advantages thereof, will be readily understood from the following detailed description and the accompanying drawings, in which:

Figure 1 illustrates a simplified wireless communication system,

Figure 2 illustrates an SSB resource allocation in time and frequency,

Figure 3 illustrates how multiple SSB blocks are distributed in time domain for different subcarrier spacings,

Figure 4 is a block diagram schematically illustrating SSB transmissions within two SSB transmission cycles,

Figure 5 illustrates indication of SSB time index from 0 to 63,

Figure 6 is a block diagram schematically illustrating a wireless communication system according to some embodiments herein,

Figure 7 is a flowchart illustrating embodiments of a method performed by a wireless communications device,

Figure 8 is a flowchart illustrating embodiments of a further method performed by a wireless communications device,

Figure 9 is a schematic block diagram illustrating embodiments of a wireless communications device,

Figure 11 schematically illustrates a telecommunication network connected via an intermediate network to a host computer. Figure 12 is a generalized block diagram of a host computer communicating via a base station with a user equipment over a partially wireless connection.

Figures 13 to 16 are flowcharts illustrating methods implemented in a communication system including a host computer, a base station and a user equipment.

DETAILED DESCRIPTION

Embodiments herein relate to wireless communication networks in general. Figure 6 is a schematic overview depicting a wireless communications network 100 wherein embodiments herein may be implemented. The wireless communications network 100 comprises one or more RANs and one or more CNs. The wireless communications network 100 may use a number of different technologies, such as Wi-Fi, Long Term Evolution (LTE), LTE-Advanced, 5G, New Radio (NR), Wideband Code Division Multiple Access (WCDMA), Global System for Mobile communications/enhanced Data rate for GSM Evolution (GSM/EDGE), Worldwide Interoperability for Microwave Access (WiMax), or Ultra Mobile Broadband (UMB), just to mention a few possible implementations. Embodiments herein relate to recent technology trends that are of particular interest in a 5G context. However, embodiments are also applicable in further development of other existing wireless communication systems such as e.g. WCDMA and LTE and in future wireless communication systems, such as 6G systems.

Access nodes operate in the wireless communications network 100 such as a radio access node 111. The radio access node 111 provides radio coverage over a geographical area, a service area referred to as a cell 115, which may also be referred to as a beam or a beam group of a first radio access technology (RAT), such as 5G, LTE, Wi-Fi or similar. There may be more than one cell. For example, there may be a second cell 116 as well. The radio access node 111 may be a NR-RAN node, transmission and reception point e.g. a base station, a radio access node such as a Wireless Local Area Network (WLAN) access point or an Access Point Station (AP STA), an access controller, a base station, e.g. a radio base station such as a NodeB, an evolved Node B (eNB, eNode B), a gNB, a base transceiver station, a radio remote unit, an Access Point Base Station, a base station router, a transmission arrangement of a radio base station, a stand-alone access point or any other network unit capable of communicating with a wireless device within the service area depending e.g. on the radio access technology and terminology used. The respective radio access node 111 may be referred to as a serving radio access node and communicates with a UE with Downlink (DL) transmissions to the UE and Uplink (UL) transmissions from the UE.

A number of wireless communications devices operate in the wireless communication network 100, such as a wireless communications device 121.

The wireless communications device 121 may be a mobile station, a non-access point (non-AP) STA, a STA, a user equipment and/or a wireless terminal, that communicate via one or more Access Networks (AN), e.g. RAN, e.g. via the radio access node 111 to one or more core networks (CN) e.g. comprising a CN node 130, for example comprising an Access Management Function (AMF). It should be understood by the skilled in the art that “UE” is a non-limiting term which means any terminal, wireless communication terminal, user equipment, Machine Type Communication (MTC) device, Device to Device (D2D) terminal, or node e.g. smart phone, laptop, mobile phone, sensor, relay, mobile tablets or even a small base station communicating within a cell.

Embodiments disclosed herein present a UE-proprietary solution for low-power detection, identification, and tracking of SSB beams in e.g. 3GPP NR RAT. However, similar solutions may be implemented in other existing communication systems or future communication systems. Embodiments herein may be used for monitoring and detecting SSB beams from both the serving cell and neighbor cells.

The wireless communications device 121 utilizes a low-power receiver (LPR) which may be a separate receiver hardware block or a reduced-power operating mode of a full receiver. The LPR may be implemented with one or more power-reduction measures like relaxed RF front end requirements, reduced bandwidth, reduced Analog to Digital Converter resolution or bandwidth, reduced number of antennas or fewer front-end branches or both, time-domain signal correlation, etc. The relaxed RF front end requirements may be relaxed compared to the requirements of the full receiver’s front end. Such relaxed requirements may include lower gain of amplifiers, worse noise figure of amplifiers and worse linearity of amplifiers which all may result in lower power demands. By doing time-domain signal correlation there is no need for Fast Fourier Transform. Further, a low resolution may be required due to the less demanding scenarios.

In embodiments herein the full receiver refers to a conventional UE receiver for conventional control and data information reception. The conventional UE receiver may for example comprise a full OFDM receiver and a PBCH decoder for decoding the coded SI payload data. The conventional UE receiver may be a cellular receiver.

In some embodiments, the wireless communications device 121 performs an optional PSS/SSS detection during a first SSB period for candidate signal detection, e.g. recoding samples and using offline processing, then performs SSB index detection during later SSB period(s). For example, the wireless communications device 121 may detect the presence of a signal and its main properties, later used to configure a simplified receiver according to embodiments herein regarding which sequences to look for.

The SSB index detection during later SSB period(s) may be performed in two parts. Three LSBs are detected via hypothesis testing of possible PBCH DM RS patterns in timedomain. For operation in deployments with more than eight SSBs, up to three MSBs may additionally be detected via hypothesis testing of possible PBCH payload patterns, using previous PBCH contents (e.g., from the previous candidate signal detection) as a baseline and adding a correction due to deterministic SFN and half-frame index changes.

Extended coherent accumulation across multiple SSB periods may be used to improve detection quality.

Exemplifying methods according to embodiments herein will now be described with reference to a flow chart in Figure 7, a second flow chart in Figure 8, an example of the wireless communications device 121 in Figure 9, and with continued reference to Figure 4 and Figure 6.

Figure 9 illustrates an example of the wireless communications device 121. The wireless communications device 121 may be configured to perform the method actions of Figure 7 and 8 below. In order to describe the methods of Figures 7 and 8 some details of the wireless communications device 121 will be described first in relation to Figure 9.

The wireless communications device 121 comprises a first RF receiver 1010 for wireless communication of data or control signals or both within the wireless communications network 100. The wireless communications device 121 further comprises a second RF receiver 1020 operating at a reduced power consumption compared to a power consumption of the first RF receiver 1010 when active. That is, when the first RF receiver 1010 is active it operates at a reduced power consumption compared to the power consumption of the first RF receiver 1010 when the first RF receiver 1010 is active. In some embodiments herein the first RF receiver 1010 is referred to as the full receiver. The second RF receiver may also be referred to as the LPR described above and implemented with the described one or more power-reduction measures.

The reduced power consumption may for example be due to front end amplifiers with lower power demands or fewer front-end branches.

The second RF receiver 1020 may also be connected to fewer antennas than the first RF receiver 1010. In Figure 9 the first RF receiver 1010 is connected to a first primary antenna 1011 and a second primary antenna 1012 while the second RF receiver 1020 is connected to a secondary antenna 1021.

As mentioned above the second RF receiver 1020 may be a separate receiver hardware block or a reduced-power operating mode of the first RF receiver 1010.

The flow chart of Figure 7 illustrates a method, performed by a wireless communications device, such as the wireless communications device 121.

The method is for beam measurement and identification in a multi-beam cell deployment of the wireless communications network 100.

The method actions may be performed in any suitable order. Some method actions may be optional.

Action 700

In this action, which may be optional or performed initially or infrequently, the wireless communications device 121 performs conventional SSB detection using the full receiver, that is using the first RF receiver 1010. The wireless communications device 121 may detect the cell group index and estimate the time and frequency offset from the PSS based on known PSS detection approaches, e.g. time or frequency or code hypothesis testing in the time domain. The time and frequency offsets refer to differences between the UE local time and frequency references and the gNB timing and frequency references used for SSB transmission. The wireless communications device 121 may then detect the SSS, e.g. in the frequency domain, to obtain a complete cell ID, and subsequently demodulate and decode the PBCH and extract reference PBCH contents, including physical layer information and MIB contents.

Action 710

In action 710, during an SSB time slot different from that used in action 700, the wireless communications device 121 uses its low-power receiver, i.e., the second RF receiver 1020, to detect the PSS and/or SSS, e.g. to obtain or refresh time or frequency synchronization for a detected cell. For example, the second RF receiver 1020 may refresh time or frequency synchronization for a previously detected cell. This may allow reducing the synchronization search range. The wireless communications device 121 may sweep all the receive beams, or just a subset of them or the best one detected in action 700 above, based on a predetermined condition. For example, the wireless communications device 121 sweeps a subset of receive beams satisfying a beam quality higher than a first beam quality threshold, or only the best beam, if the best beam quality is higher than a second beam quality threshold, where the second threshold is higher than the first one.

Action 720

In action 720, the wireless communications device 121 detects the associated PBCH using the LPR. The PBCH detection may include beam index (aka. SS/PBCH block index) detection via DMRS scrambling, where different DMRS RE sequences corresponding to different beam indices (up to 3 LSBs) are used as reference sequences when correlating with the received signal. This action provides complete beam index information if the deployment is limited to eight beams or less, or the number of actually transmitted SSBs is eight or less.

Action 730

In action 730, if the number of SSB beams exceeds eight, the wireless communications device 121 may further perform PBCH payload detection for finding the MSB of the beam ID of the SSB. Multiple hypotheses of encoded payload contents incorporating beam index MBSs (up to three) may be used as reference sequences. The payload contents are deterministic, varying only due to an advancing frame counter, such as the SFN. The wireless communications device 121 may use the full receiver once, or infrequently, to obtain the current SFN and assume it to be known in future detection occasions. The payload hypotheses may thus use the decoded PBCH contents obtained in action 700 as a baseline, and then modify individual fields, such as the hypothesized beam index, current SFN, current half-frame indication, that may have changed compared to the decoded PBCH in action 700, and re-encoding the modified payload.

For both actions 720 and 730, the PBCH detection may be performed in the time domain, where the reference signals for DMRS and PBCH hypotheses are formed as time domain representation of the REs containing relevant DMRS or PBCH payload information. Depending on the quality of the time or frequency synchronization, multiple time or frequency offsets may be included in the hypothesis space. The wireless communications device 121 may perform time-domain correlation detection of PBCH DMRS and payload patterns. The wireless communications device 121 may further perform matched filter detection using hypothesized DMRS scrambling sequences that are a function of beam ID and encoded payload patterns to obtain the first three bits and up to three last bits of the beam ID, respectively.

The detection may also be performed in the F-domain if reliable T/F offset estimation and correction has been applied and a robust FFT window is determined. The LPR in the wireless communications device 121 may use a small-size (e.g. size-256) FFT and perform DMRS sequence detection and PBCH contents detection in the F-domain REs. In one alternative, the LPR may use an efficient PBCH decoder to directly obtain the additional beam ID bits.

At high Signal to Interference plus Noise Ratio (SINR), reliable DMRS pattern and PBCH payload detection may be achieved using fewer samples. In one embodiment, the wireless communications device 121 may select only a subset of PBCH samples for detection processing, e.g. only symbol 2, symbol 2 and 4, or all symbols 2-4, depending on the signal SINR.

Action 740

In this action, the detected beam index from PBCH processing may be used in beam management procedures or RRM procedures. For example, a relatively static wireless communications device 121 may monitor one or more previously identified SSB beams over time and take no action while the related signal strengths, e.g., estimated on the SSS or the PBCH of the same beams, vary less than a threshold. If the variation exceeds the threshold, the wireless communications device 121 may activate the full receiver for complementary measurements, reporting, etc. and/or autonomously perform e.g., beam switching or camping cell change. The wireless communications device 121 may also use the beam index detection to verify that the periodic SSB monitoring timing has not shifted to a suboptimal beam and correct the monitoring window if needed.

Further detailed examples

In some first embodiments, the wireless communications device 121 monitors the SSS of the currently known best beam with the second RF receiver 1020, at known time instants after action 100, without performing further beam index detection. Once changes in SSS Reference Signal Received Power (RSRP) or SINR of the currently known best beam are detected by the second RF receiver 1020, the wireless communications device 121 may invoke procedures described herein. For example, once changes in SSS RSRP or SI NR are detected the wireless communications device 121 may perform beam index detection, i.e., detection of SS block time index, for additional beam positions for which PBCH and/or SSS signal quality exceeds the threshold. As described above in action 720 and action 730 detection of SS block time index is based on detecting PBCH sequences and optionally PBCH payload if L>8. To do this, the wireless communications device 121 may also consider additional conditions, e.g., if the initial SSS RSRP, SSS Reference Signal Received Quality (RSRQ), or SSS SINR is higher than a first threshold of a beam quality metric, then the wireless communications device 121 may apply the LPR for SSS tracking of the best beam. However, if it is lower than the first threshold then the wireless communications device 121 employs the full receiver. Here tracking refers to maintaining the knowledge of the best beam identity and its approximate time or frequency references or both so that subsequent detection and e.g. the SSB index detection according to embodiments herein may be performed with low effort and valid reference settings. The wireless communications device 121 may additionally consider tracking a subset of SSS associated with different beam indices instead of only the best beam. E.g., if the wireless communications device 121 tracks the SSS of a subset of beams with a specific beam quality metric (e.g., SSS RSRP/RSRQ/SINR) being higher than the first threshold, but if the best beam quality metric is more than a second threshold of a beam quality metric, then the wireless communications device 121 only tracks the best beam, where the second threshold is higher than the first threshold. Another type of change may also be that the tracked SSS is not associated with the previously known cell identifier, i.e., the SSS now belongs to a new cell, and thus may be a different beam index. In this case the wireless communications device 121 may invoke the procedures disclosed herein, or revert back to operating the full receiver to track the new neighbor cell and identify the associated beams.

In some second embodiments, the wireless communications device 121 may also use the PBCH measurements for signal quality estimation for the different SSB beams, omitting or augmenting traditional SSS-based signal quality measurements. The PBCH- based signal quality may be estimated by using the PBCH contents, detected with the first RF receiver 1010 in action 700, as a reference sequence for correlating with the sample sequence, received with the second RF receiver 1020, using relevant PBCH REs (DMRS or entire PBCH contents). In other words, either only REs containing DMRS samples are used, or all REs are used, for correlation. The wireless communications device 121 may also use this in order to track if the beam index has changed. E.g., if the correlation of the measured PBCH with the previously known PBCH is more than a PBCH correlation threshold, then the wireless communications device 121 knows that the beam index remained the same, but if it is lower than the PBCH correlation threshold, then the wireless communications device 121 may invoke the procedures disclosed herein or revert back to the full receiver to detect the new beam index.

In some further embodiments, the wireless communications device 121 may use PBCH-based quality estimates (i.e. using symbols 2 and 4 of SSB, in addition or instead of symbol 3 containing also SSS) from the second RF receiver 1020 to determine the need for SSS-based RRM measurements. More symbols mean more usable REs and higher signal power to get better measurement quality. The wireless communications device 121 may perform SSS-based measurements, using the second RF receiver 1020 or the first RF receiver 1010, e.g. when the PBCH-based estimate drops below a threshold, decreases or increases more than a threshold, or other criteria.

In yet some further embodiments, the wireless communications device 121 knows the SSB indexes and it may then use the second RF receiver 1020 with PSS and SSS in the coarse location of the best beam to track if the best beam is still the same or has changed. For example, the wireless communications device 121 in the full receiver mode finds a best beam, then the wireless communications device 121 may keep track of the best beam in the serving cell, or in the neighbor cells with the second RF receiver 1020. If e.g., the best beam quality reduces more than a beam quality threshold, then the wireless communications device 121 applies the hypothesis testing looking for a new best beam with the second RF receiver 1020. The wireless communications device 121 may also go back to full receiver mode. The wireless communications device 121 may also additionally consider conditions to do this, e.g., if the wireless communications device 121 is not mobile or not at the cell edge, etc.

In some related embodiments, the wireless communications device 121 uses the full receiver for first beam detection and identification as described above in action 700. The wireless communications device 121 then keeps track of the best beam, or a subset of beams in serving and neighbor cells with the second RF receiver 1020 based on a condition, e.g., a condition for beam quality, RSRP, etc. When the wireless communications device 121 detects a change or a potential change in the beam quality, then it invokes the hypothesis testing using the second RF receiver 1020 (this corresponds to actions 720 and 730 above), based on a condition (e.g., consistent hypothesis testing results). For example, if the hypothesis testing result changes (e.g., something has changed in the environment), switch to a more robust detection mode. The change, may be e.g., due to a change in the SSB configuration, detection of a new neighbor cell, mobility of the wireless communications device 121 , etc. The wireless communications device 121 then returns to action 710.

Exemplifying methods according to embodiments herein will now be described with reference to a flow chart in Figure 8 which complements the flow chart of Figure 7 and with continued reference to Figures 5a and Figure 6. The flow chart of Figure 8 illustrates a method, performed by the wireless communications device 121.

The method is for beam measurement and identification in a multi-beam cell deployment of the wireless communications network 100. Specifically, the method is for identifying a beam used to broadcast an RS.

The method may be performed when the wireless communications device 121 is not scheduled to transmit or receive data. The wireless communications device 121 may be in an idle, inactive, or connected mode.

The wireless communications device 121 comprises a first RF receiver 1010 for wireless communication of data or control signals or both within the wireless communications network 100 and a second RF receiver 1020 operating at a reduced power consumption compared to a power consumption of the first RF receiver 1010 when active

Action 801

The wireless communications device 121 may receive one or more previous samples of a broadcasted RS by the first RF receiver 1010.

The broadcasted RS may be comprised in an SSB. For example, in 3gpp NR networks the RS may be a PBCH DM RS in the PBCH component of the SSB.

Action 802 In some embodiments herein the wireless communications device 121 determines one or more RS hypotheses based on the one or more previous samples of the broadcasted RS received by the first RF receiver 1010.

The determined one or more RS hypotheses may be shared with the second RF receiver 1020 which may use the RS hypotheses to correlate with future received RSs comprising beam identifier information to check which RS hypothesis that fits with the future received RSs. Thus, the second RF receiver 1020 may determine a beam identifier based on a time-domain correlation of a part of a received RS comprising beam identifier information and one or more of the determined one or more RS hypotheses.

Action 803

In action 803 the wireless communications device 121 receives from the network node 111 of the wireless communications network 100 and by the second RF receiver 1020, one or more samples of a broadcasted RS associated with a beam 41 , 42, 43, 44.

The RS may be used by the first RF receiver 1010 for demodulating and decoding coded System Information, SI, payload data broadcasted on a physical channel.

The RS and the coded SI payload data may be comprised in the SSB.

For example, in 3gpp NR networks the RS may be a PBCH DMRS in the PBCH component of the SSB. The SI payload data may be PBCH payload data.

In some embodiments herein receiving the one or more samples of the RS comprises coherent or non-coherent accumulation or both of the one or more samples of the RS across multiple periods for transmitting the RS. The multiple periods for transmitting the RS may be multiple SSB periods.

Coherent accumulation over multiple periods for transmitting the RS may be achieved by keeping a clock or LO of the second receiver 1020 stable over multiple periods, such as over a 20 ms interval used for SSBs in NR, to main maintain phase coherence over the multiple periods.

Action 804

The wireless communications device 121 then determines a beam identifier of the beam 41, 42, 43, 44 based on a time-domain correlation of the received one or more samples of the RS with the one or more RS hypotheses.

In some embodiments herein the beam identifier comprises one or more bits. Then determining the beam identifier of the beam 41 , 42, 43, 44 based on the time-domain correlation of the received one or more samples of the broadcasted RS with the one or more RS hypotheses may comprises determining part or all of the one or more bits of the beam identifier based on the time-domain correlation of the received one or more samples of the RS with the one or more RS hypotheses, and determining the beam identifier based on the determined part or all of the one or more bits.

Determining part or all of the one or more bits may comprise determining LSBs of the beam identifier based on the time-domain correlation of the received one or more samples of the RS with the one or more RS hypotheses. As mentioned above there may be 2 or 3 LSBs of the beam identifier. For NR SS block time index are indicated by two LSBs of the three bits indicating eight different PBCH-DMRS sequences for L=4. For L>4 there are three LSBs.

In some embodiments herein determining the beam identifier of the beam 41 , 42, 43, 44 further comprises determining MSBs of the beam identifier by detecting the coded SI payload data with the second RF receiver 1020 and determining the beam identifier further based on the determined MSBs.

Detecting the coded SI payload data with the second RF receiver 1020 may comprise receiving, from the network node 111 and by the second RF receiver 1020, one or more samples of a second signal carrying the coded SI payload data. The second signal may be a PBCH signal carrying payload data. The coded SI payload data is detected based on a time-domain correlation of the second signal carrying the coded SI payload data with a third signal carrying a hypothesis of the SI payload data.

The hypothesis of the SI payload data may be obtained based on demodulating and decoding previous SI payload data with the first RF receiver 1010.

Action 805

The SSB may further comprise signals for synchronization, such as PSS and SSS in NR. Then the method may further comprise detecting, by the second RF receiver 1020, the signals for synchronization comprised in the SSB.

Action 806

In some embodiments herein the wireless communications device 121 performs, based on the detected signals for synchronization and the determined beam identifier, any one or more of: beam monitoring or beam selection or beam measurement procedures.

Additional embodiments The wireless communications device 121 may be operating in connected mode wherein embodiments herein are applied between active data transmission segments or cDRX on-durations.

The wireless communications device 121 may also be operating in idle/inactive mode wherein embodiments herein are invoked between paging monitoring occasions. The wireless communications device 121 is typically aware of which beams to follow and track, the beam detection with the second RF receiver 1020 according to embodiments herein may still be applicable in idle/inactive mode since beam identification may be used to verify beams when the wireless communications device 121 tracks specific beams. When the wireless communications device 121 detects beam failure, then it may use the embodiments herein to find the best beams with the second RF receiver 1020 at a reduced power. Embodiments herein may also be applied to Radio Link Monitoring (RLM), when the wireless communications device 121 performs RLM on known beams and verifies the beams in the process using the second RF receiver 1020.

In some embodiments, if the second RF receiver 1020 does not have sufficient performance in low-SNR scenarios due to RF impairments or other impairments, the wireless communications device 121 invokes embodiments herein only if the signal quality exceeds a signal quality threshold, to meet detection and measurement performance in all scenarios.

In some other embodiments, the wireless communications device 121 applies the embodiments herein if e.g., it has detected a low mobility of the wireless communications device 121 (e.g., either based on a threshold configured by the NW or based on its own determination), or if it has detected that it is not close to the cell edge (e.g., either based on a threshold configured by the NW or set by the wireless communications device 121 itself). Alternatively, for robustness reasons, the wireless communications device 121 applies the embodiments herein when it has detected both low mobility and not being close to the cell edge. In a related realization, the wireless communications device 121 only applies the LPR procedures in this IvD when it is in RRM/RLM/BFD relaxation mode.

In yet some further embodiments, to allow lower front end quality of the second RF receiver 1020 or a lower number of RX antennas of the second RF receiver 1020 or both, the second RF receiver 1020 may perform coherent accumulation from multiple SSB instances by maintaining sample-level coherence across the 20 ms inter-measurement time, e.g. by employing a sufficiently stable LO that does not drift excessively during 20 ms.

Alternatively, the wireless communications device 121 may non-coherently combine coherent hypothesis testing results from multiple SSB periods. This may for example be performed by saving correlation magnitudes for each hypothesis from the previous period and add to them the respective magnitudes from the current period, etc., including repeating this over multiple periods. The choice of combining coherently or non-coherently may be based on a clock accuracy of the wireless communications device 121. For example, if the clock accuracy is good then it may be possible to combine coherently. The clock accuracy between SSBs may be selected considering aggregate power consumption of the second RF receiver 1020. For example, if the aggregate power consumption is high then the wireless communications device 121 may lower the clock accuracy, i.e. , select a lower clock accuracy.

For additional robustness, the wireless communications device 121 may perform occasional full receiver measurements to narrow or verify the beam ID search space and to monitor timing of the wireless communications network 100 based on SSBs.

In some embodiments disclosed herein, the LPR operation is used to perform sufficient link quality verification only for the serving cell or beam. No additional SSBs are searched. The wireless communications device 121 only evaluates a quality of a current best beam with a known ID. By performing link quality verification only for the serving cell or beam the power consumption of the wireless communications device 121 may be decreased even further.

As mentioned above Figure 9 illustrates an example of the wireless communications device 121. The wireless communications device 121 may be configured to perform the method actions of Figure 7 and 8 above.

Thus, the wireless communications device 121 is configured for beam measurement and identification in a multi-beam cell deployment of the wireless communications network 100. The wireless communications device 121 may be configured to perform the method when the wireless communications device 121 is not scheduled to transmit or receive data. The wireless communications device 121 is further configured to receive, from the network node 111 of the wireless communications network 100 and by the second RF receiver 1020, the one or more samples of the broadcasted RS associated with the beam 41, 42, 43, 44 and to determine a beam identifier of the beam 41, 42, 43, 44 based on the time-domain correlation of the received one or more samples of the RS with the one or more RS hypotheses.

In some embodiments herein the first RF receiver 1010 comprises the full OFDM receiver and the decoder 1030 for decoding the coded SI payload data. Then the second RF receiver 1020 does not comprise an active full OFDM receiver nor an active decoder for decoding the coded SI payload data.

The second RF receiver 1020 may be electromagnetically connected to a lower number of antennas than the first RF receiver 1010, such as one antenna 1021.

In some embodiments herein the wireless communications device 121 is configured to determine part or all of the one or more bits of the beam identifier based on the timedomain correlation of the received one or more samples of the RS with the one or more RS hypotheses and to determine the beam identifier based on the determined part or all of the one or more bits.

The wireless communications device 121 may be configured to receive one or more previous samples of the broadcasted RS by the first RF receiver 1010 and to determine the one or more RS hypotheses based on the one or more previous samples of the broadcasted RS received by the first RF receiver 1010.

In some embodiments herein the wireless communications device 121 is configured to determine part or all of the one or more bits by being configured to: determine LSBs of the beam identifier based on the time-domain correlation of the received one or more samples of the RS with the one or more RS hypotheses.

The wireless communications device 121 may be further configured to determine the beam identifier of the beam 41 , 42, 43, 44 by being configured to determine MSBs of the beam identifier by detecting the coded SI payload data with the second RF receiver 1020 and determine the beam identifier further based on the determined MSBs. In some embodiments herein the wireless communications device 121 is configured to detect the coded SI payload data with the second RF receiver 1020 comprises receiving, from the network node 111 and by the second RF receiver 1020, one or more samples of a second signal carrying the coded SI payload data, wherein the coded SI payload data is detected based on a time-domain correlation of the second signal carrying the coded SI payload data with a third signal carrying a hypothesis of the SI payload data.

The wireless communications device 121 may be further configured to obtain the hypothesis of the SI payload data is based on demodulating and decoding previous SI payload data with the first RF receiver 1010.

In some embodiments herein when the SSB further comprises signals for synchronization the wireless communications device 121 may be configured to detect, by the second RF receiver 1020, the signals for synchronization comprised in the SSB and perform, based on the detected signals for synchronization and the determined beam identifier, any one or more of: beam monitoring or beam selection or beam measurement procedures.

The wireless communications device 121 may be further configured to receive the one or more samples of the RS by being configured for coherent or non-coherent accumulation or both of the one or more samples of the RS across multiple periods for transmitting the RS.

The wireless communications device 121 may comprise an input and output interface, IF, 1006, configured to communicate, e.g., with the radio access node 111. The input and output interface 1006 may comprise the first and second RF receivers 1010, 1020 and one or more transmitters (not shown). The receivers and the transmitters may be wireless.

The embodiments herein may be implemented through a processor or one or more processors, such as the processor 1004, of a processing circuitry in the wireless communications device 121 , and depicted in Figure 9 together with computer program code for performing the functions and actions of the embodiments herein. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the wireless communications device 121. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the wireless communications device 121.

The wireless communications device 121 may further comprise a memory 1002 comprising one or more memory units. The memory comprises instructions executable by the processor in the wireless communications device 121.

The respective memory 1002 is arranged to be used to store e.g. information, data, configurations, and applications to perform the methods herein when being executed in the wireless communications device 121.

In some embodiments, a computer program 1003 comprises instructions, which when executed by the at least one processor, cause the at least one processor of the wireless communications device 121 to perform the actions above.

In some embodiments, a carrier 1005 comprises the computer program, wherein the carrier is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or a computer- readable storage medium.

Those skilled in the art will also appreciate that the units described above may refer to a combination of analog and digital circuits, and/or one or more processors configured with software and/or firmware, e.g. stored in the wireless communications device 121 , that when executed by the respective one or more processors such as the processors described above. One or more of these processors, as well as the other digital hardware, may be included in a single Application-Specific Integrated Circuitry (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a system-on-a-chip (SoC). With reference to Figure 10, in accordance with an embodiment, a communication system includes a telecommunication network 3210, such as a 3GPP-type cellular network, which comprises an access network 3211, such as a radio access network, and a core network 3214. The access network 3211 comprises a plurality of base stations 3212a, 3212b, 3212c, such as the source and target access node 111 , 112, AP STAs NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 3213a, 3213b, 3213c. Each base station 3212a, 3212b, 3212c is connectable to the core network 3214 over a wired or wireless connection 3215. A first user equipment (UE) such as a Non-AP STA 3291 located in coverage area 3213c is configured to wirelessly connect to, or be paged by, the corresponding base station 3212c. A second UE 3292 such as a Non-AP STA in coverage area 3213a is wirelessly connectable to the corresponding base station 3212a. While a plurality of UEs 3291 , 3292 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 3212.

The telecommunication network 3210 is itself connected to a host computer 3230, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. The host computer 3230 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. The connections 3221, 3222 between the telecommunication network 3210 and the host computer 3230 may extend directly from the core network 3214 to the host computer 3230 or may go via an optional intermediate network 3220. The intermediate network 3220 may be one of, or a combination of more than one of, a public, private or hosted network; the intermediate network 3220, if any, may be a backbone network or the Internet; in particular, the intermediate network 3220 may comprise two or more subnetworks (not shown).

The communication system of Figure 10 as a whole enables connectivity between one of the connected UEs 3291 , 3292 such as e.g. the wireless communications device 121, and the host computer 3230. The connectivity may be described as an over- the-top (OTT) connection 3250. The host computer 3230 and the connected UEs 3291, 3292 are configured to communicate data and/or signaling via the OTT connection 3250, using the access network 3211, the core network 3214, any intermediate network 3220 and possible further infrastructure (not shown) as intermediaries. The OTT connection 3250 may be transparent in the sense that the participating communication devices through which the OTT connection 3250 passes are unaware of routing of uplink and downlink communications. For example, a base station 3212 may not or need not be informed about the past routing of an incoming downlink communication with data originating from a host computer 3230 to be forwarded (e.g., handed over) to a connected UE 3291. Similarly, the base station 3212 need not be aware of the future routing of an outgoing uplink communication originating from the UE 3291 towards the host computer 3230.

Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to Figure 11. In a communication system 3300, a host computer 3310 comprises hardware 3315 including a communication interface 3316 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 3300. The host computer 3310 further comprises processing circuitry 3318, which may have storage and/or processing capabilities. In particular, the processing circuitry 3318 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The host computer 3310 further comprises software 3311 , which is stored in or accessible by the host computer 3310 and executable by the processing circuitry 3318. The software 3311 includes a host application 3312. The host application 3312 may be operable to provide a service to a remote user, such as a UE 3330 connecting via an OTT connection 3350 terminating at the UE 3330 and the host computer 3310. In providing the service to the remote user, the host application 3312 may provide user data which is transmitted using the OTT connection 3350.

The communication system 3300 further includes a base station 3320 provided in a telecommunication system and comprising hardware 3325 enabling it to communicate with the host computer 3310 and with the UE 3330. The hardware 3325 may include a communication interface 3326 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 3300, as well as a radio interface 3327 for setting up and maintaining at least a wireless connection 3370 with a UE 3330 located in a coverage area (not shown in Figure 11) served by the base station 3320. The communication interface 3326 may be configured to facilitate a connection 3360 to the host computer 3310. The connection 3360 may be direct or it may pass through a core network (not shown in Figure 11) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, the hardware 3325 of the base station 3320 further includes processing circuitry 3328, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The base station 3320 further has software 3321 stored internally or accessible via an external connection.

The communication system 3300 further includes the UE 3330 already referred to. Its hardware 3335 may include a radio interface 3337 configured to set up and maintain a wireless connection 3370 with a base station serving a coverage area in which the UE 3330 is currently located. The hardware 3335 of the UE 3330 further includes processing circuitry 3338, which may comprise one or more programmable processors, applicationspecific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The UE 3330 further comprises software 3331, which is stored in or accessible by the UE 3330 and executable by the processing circuitry 3338. The software 3331 includes a client application 3332. The client application 3332 may be operable to provide a service to a human or non-human user via the UE 3330, with the support of the host computer 3310. In the host computer 3310, an executing host application 3312 may communicate with the executing client application 3332 via the OTT connection 3350 terminating at the UE 3330 and the host computer 3310. In providing the service to the user, the client application 3332 may receive request data from the host application 3312 and provide user data in response to the request data. The OTT connection 3350 may transfer both the request data and the user data. The client application 3332 may interact with the user to generate the user data that it provides. It is noted that the host computer 3310, base station 3320 and UE 3330 illustrated in Figure 11 may be identical to the host computer 3230, one of the base stations 3212a, 3212b, 3212c and one of the UEs 3291 , 3292 of Figure 10, respectively. This is to say, the inner workings of these entities may be as shown in Figure 11 and independently, the surrounding network topology may be that of Figure 10.

In Figure 11, the OTT connection 3350 has been drawn abstractly to illustrate the communication between the host computer 3310 and the use equipment 3330 via the base station 3320, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from the UE 3330 or from the service provider operating the host computer 3310, or both. While the OTT connection 3350 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

The wireless connection 3370 between the UE 3330 and the base station 3320 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE 3330 using the OTT connection 3350, in which the wireless connection 3370 forms the last segment. More precisely, the teachings of these embodiments may improve the data rate, latency, power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime.

A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 3350 between the host computer 3310 and UE 3330, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 3350 may be implemented in the software 3311 of the host computer 3310 or in the software 3331 of the UE 3330, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 3350 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 3311, 3331 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 3350 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect the base station 3320, and it may be unknown or imperceptible to the base station 3320. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer’s 3310 measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that the software 3311, 3331 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 3350 while it monitors propagation times, errors etc.

FIGURE 12 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station such as a AP STA, and a UE such as a Non-AP STA which may be those described with reference to Figure 10 and Figure 11. For simplicity of the present disclosure, only drawing references to Figure 12 will be included in this section. In a first action 3410 of the method, the host computer provides user data. In an optional subaction 3411 of the first action 3410, the host computer provides the user data by executing a host application. In a second action 3420, the host computer initiates a transmission carrying the user data to the UE. In an optional third action 3430, the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In an optional fourth action 3440, the UE executes a client application associated with the host application executed by the host computer.

FIGURE 13 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station such as a AP STA, and a UE such as a Non-AP STA which may be those described with reference to Figure 10 and Figure 11. For simplicity of the present disclosure, only drawing references to Figure 13 will be included in this section. In a first action 3510 of the method, the host computer provides user data. In an optional subaction (not shown) the host computer provides the user data by executing a host application. In a second action 3520, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In an optional third action 3530, the UE receives the user data carried in the transmission.

FIGURE 14 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station such as a AP STA, and a UE such as a Non-AP STA which may be those described with reference to Figure 10 and Figure 11. For simplicity of the present disclosure, only drawing references to Figure 14 will be included in this section. In an optional first action 3610 of the method, the UE receives input data provided by the host computer. Additionally or alternatively, in an optional second action 3620, the UE provides user data. In an optional subaction 3621 of the second action 3620, the UE provides the user data by executing a client application. In a further optional subaction 3611 of the first action 3610, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in an optional third subaction 3630, transmission of the user data to the host computer. In a fourth action 3640 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure.

FIGURE 15 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station such as a AP STA, and a UE such as a Non-AP STA which may be those described with reference to Figures 10 and 11. For simplicity of the present disclosure, only drawing references to Figure 15 will be included in this section. In an optional first action 3710 of the method, in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In an optional second action 3720, the base station initiates transmission of the received user data to the host computer. In a third action 3730, the host computer receives the user data carried in the transmission initiated by the base station.

When using the word "comprise" or “comprising” it shall be interpreted as nonlimiting, i.e. meaning "consist at least of".

The embodiments herein are not limited to the above described preferred embodiments. Various alternatives, modifications and equivalents may be used.

Claims

1. A method, performed by a wireless communications device (121), for beam measurement and identification in a multi-beam cell deployment of a wireless communications network (100), the wireless communications device (121) comprising a first Radio Frequency, RF, receiver (1010) for wireless communication of data or control signals or both within the wireless communications network (100) and a second RF receiver (1020) operating at a reduced power consumption compared to a power consumption of the first RF receiver (1010) when active, the method comprises: receiving (803), from a network node (111) of the wireless communications network (100) and by the second RF receiver (1020), one or more samples of a broadcasted Reference Signal, RS, associated with a beam (41 , 42, 43, 44); and determining (804) a beam identifier of the beam (41 , 42, 43, 44) based on a time-domain correlation of the received one or more samples of the RS with one or more RS hypotheses.

2. The method according to claim 1 , wherein the RS is used by the first RF receiver (1010) for demodulating and decoding coded System Information, SI, payload data broadcasted on a physical channel.

3. The method according to claim 1 or 2, wherein the beam identifier comprises one or more bits and wherein determining the beam identifier of the beam (41 , 42, 43, 44) based on the time-domain correlation of the received one or more samples of the RS with the one or more RS hypotheses comprises: determining part or all of the one or more bits, of the beam identifier based on the time-domain correlation of the received one or more samples of the RS with the one or more RS hypotheses; and determining the beam identifier based on the determined part or all of the one or more bits.

4. The method according to any of the claims 1-3, further comprising: receiving (801) one or more previous samples of the broadcasted RS by the first RF receiver (1010) and determining (802) the one or more RS hypotheses based on the one or more previous samples of the broadcasted RS received by the first RF receiver (1010).

5. The method according to any of the claims 2-4, wherein the RS and the coded SI payload data are comprised in a Synchronization Signal Block, SSB.

6. The method according to any of the claims 3-5, wherein determining part or all of the one or more bits comprises: determining Least Significant Bits, LSBs, of the beam identifier based on the time-domain correlation of the received one or more samples of the RS with the one or more RS hypotheses.

7. The method according to claim 6, wherein determining the beam identifier of the beam (41 , 42, 43, 44) further comprises: determining Most Significant Bits, MSBs, of the beam identifier by detecting the coded SI payload data with the second RF receiver (1020); and determining the beam identifier further based on the determined MSBs.

8. The method according to claim 7, wherein detecting the coded SI payload data with the second RF receiver (1020) comprises receiving, from the network node (111) and by the second RF receiver (1020), one or more samples of a second signal carrying the coded SI payload data, wherein the coded SI payload data is detected based on a time-domain correlation of the second signal carrying the coded SI payload data with a third signal carrying a hypothesis of the SI payload data.

9. The method according to claim 8, wherein the hypothesis of the SI payload data is obtained based on demodulating and decoding previous SI payload data with the first RF receiver (1010).

10. The method according to any of the claims 4-9, wherein the SSB further comprises signals for synchronization and the method further comprises: detecting (805), by the second RF receiver (1020), the signals for synchronization comprised in the SSB; and performing (806), based on the detected signals for synchronization and the determined beam identifier, any one or more of: beam monitoring or beam selection or beam measurement procedures.

11. The method according to any of the claims 1-10, wherein receiving the one or more samples of the RS comprises coherent or non-coherent accumulation or both of the one or more samples of the RS across multiple periods for transmitting the RS.

12. The method according to any of the claims 1-11 , performed when the wireless communications device (121) is not scheduled to transmit or receive data.

13. A wireless communications device (121) configured for beam measurement and identification in a multi-beam cell deployment of a wireless communications network (100), the wireless communications device (121) comprising a first Radio Frequency, RF, receiver (1010) for wireless communication of data or control signals or both within the wireless communications network (100) and a second RF receiver (1020) operating at a reduced power consumption compared to a power consumption of the first RF receiver (1010) when active, wherein the wireless communications device (121) is further configured to: receive, from a network node (111) of the wireless communications network (100) and by the second RF receiver (1020), one or more samples of a broadcasted Reference Signal, RS, associated with a beam (41 , 42, 43, 44); and determine a beam identifier of the beam (41 , 42, 43, 44) based on a time-domain correlation of the received one or more samples of the RS with one or more RS hypotheses.

14. The wireless communications device (121) according to according to claim 13, further configured to perform the method according to any of the claims 2-12.

15. The wireless communications device (121) according to any of the claims 13-14, wherein the first RF receiver (1010) comprises a full Orthogonal Frequency Division Multiplexing, OFDM, receiver and a decoder (1030) for decoding the coded SI payload data and wherein the second RF receiver (1020) does not comprise an active full OFDM receiver nor an active decoder for decoding the coded SI payload data.

16. The wireless communications device (121) according to any of the claims 13-15 wherein the second RF receiver (1020) is electromagnetically connected to a lower number of antennas than the first RF receiver (1010), such as one antenna (1021).

17. A computer program (1003), comprising computer readable code units which when executed on a wireless communications device (121) causes the wireless communications device (121) to perform the method according to any one of claims 1- 12.

18. A carrier (1005) comprising the computer program according to the preceding claim, wherein the carrier (1005) is one of an electronic signal, an optical signal, a radio signal and a computer readable medium.