Coherency indication

Abstract

A method includes receiving by a device, capable of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in one or more time units, from a network node, a configuration of reference signal resources, receiving reference signals via the configured reference signal resources, acquiring, based on measurements on the reference signals, downlink channel state information (CSI) associated with antenna ports of the configured reference signal resources over the one or more time units, while maintaining at least one of the receiver phase coherence or the amplitude coherence over the one or more time units.

Description

COHERENCY INDICATIONTECHNICAL FIELD

[0001] This description relates to wireless communications.BACKGROUND

[0002] A communication system may be a facility that enables communication between two or more nodes or devices, such as fixed or mobile communication devices. Signals can be carried on wired or wireless carriers.

[0003] An example of a cellular communication system is an architecture that is being standardized by the 3rd Generation Partnership Project (3GPP). A recent development in this field is often referred to as the long-term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio-access technology. EUTRA (evolved UMTS Terrestrial Radio Access) is the air interface of 3GPP's Long Term Evolution (LTE) upgrade path for mobile networks. In LTE, base stations or access points (APs), which are referred to as enhanced Node AP (eNBs), provide wireless access within a coverage area or cell. In LTE, mobile devices, or mobile stations are referred to as user equipments (UE). LTE has included a number of improvements or developments. Aspects of LTE are also continuing to improve.

[0004] 5G New Radio (NR) development is part of a continued mobile broadband evolution process to meet the requirements of 5G, similar to earlier evolution of 3G and 4G wireless networks. In addition, 5G is also targeted at the new emerging use cases in addition to mobile broadband. A goal of 5G is to provide significant improvement in wireless performance, which may include new levels of data rate, latency, reliability, and security. 5G NR may also scale to efficiently connect the massive Internet of Things (loT) and may offer new types of mission-critical services. For example, ultra-reliable and low- latency communications (URLLC) devices may require high reliability and very low latency. 6G and other networks are also being developed.SUMMARY

[0005] In some aspects, the techniques described herein relate to an apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, by the apparatus, capable of maintaining at least one of receiver phase coherence or amplitudecoherence of one or more received signals in one or more time units, from a network node, a configuration of reference signal resources; receive, reference signals via the configured reference signal resources; and acquire, based on measurements on the reference signals, downlink channel state information (CSI) associated with antenna ports of the configured reference signal resources over the one or more time units, while maintaining at least one of the receiver phase coherence or the amplitude coherence over the one or more time units.

[0006] In some aspects, the techniques described herein relate to an apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a user device, a capability indication of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in one or more time units; transmit, based on the capability indication, a configuration of reference signal resources; and transmit, reference signals via the configured reference signal resources.

[0007] In some aspects, the techniques described herein relate to a method including: receiving, by a user device, capable of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in one or more time units, from a network node, a configuration of reference signal resources; receiving reference signals via the configured reference signal resources; and acquiring, based on measurements on the reference signals, downlink channel state information (CSI) associated with antenna ports of the configured reference signal resources over the one or more time units, while maintaining at least one of the receiver phase coherence or the amplitude coherence over the one or more time units.

[0008] In some aspects, the techniques described herein relate to a method including: receiving, by a network node from a user device, a capability indication of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in one or more time units; transmitting, based on the capability indication, a configuration of reference signal resources; and transmitting reference signals via the configured reference signal resources.

[0009] Other example embodiments are provided or described for each of the example methods, including: means for performing any of the example methods; a non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor, are configured to cause a computing system to performany of the example methods; and an apparatus including at least one processor, and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform any of the example methods.

[0010] The details of one or more examples of embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. l is a block diagram of a wireless network.

[0012] FIG. 2 is a diagram illustrating a multiple input multiple output (MIMO) transmission.

[0013] FIG. 3 is a diagram illustrating an example 128-AP NZP-CSI-RS resource configuration with four 32-AP NZP-CSI-RSs distributed across two consecutive slots.

[0014] FIG. 4 is a diagram illustrating an aspect of an example embodiment.

[0015] FIG. 5 is a flow chart illustrating operation of an apparatus (e.g., which may be a UE or user device, or other apparatus) according to an example embodiment.

[0016] FIG. 6 is a flow chart illustrating operation of an apparatus (e.g., which may be a gNB or network node, or other apparatus) according to an example embodiment.

[0017] FIG. 7 is a block diagram of a wireless station or node (e.g., network node (such as gNB), user node or UE, relay node, or other node).DETAILED DESCRIPTION

[0018] It shall be understood that although the terms “first,” “second,”. . ., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0019] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

[0020] FIG. 1 is a block diagram of a wireless network 130. In the wireless network 130 of FIG. 1, user devices 131, 132, 133 and 135, which may also be referred to as mobile stations (MSs) or user equipment (UEs), may be connected (and in communication) with a base station (BS) 134, which may also be referred to as an access point (AP), an enhanced Node B (eNB), a gNB or a network node. The terms user device and user equipment (UE) may be used interchangeably. A BS may also include or may be referred to as a RAN (radio access network) node, and may include a portion of a BS or a portion of a RAN node, such as e.g., such as a centralized unit (CU) and / or a distributed unit (DU) in the case of a split BS or split gNB. At least part of the functionalities of a BS (e.g., access point (AP), base station (BS) or (e)Node B (eNB), gNB, RAN node) may also be carried out by any node, server or host which may be operably coupled to a transceiver, such as a remote radio head. BS (or AP) 134 provides wireless coverage within a cell 136, including to user devices (or UEs) 131, 132, 133 and 135. Although only four user devices (or UEs) are shown as being connected or attached to BS 134, any number of user devices may be provided. BS 134 is also connected to a core network 150 via a SI interface 151. This is merely one simple example of a wireless network, and others may be used.

[0021] A base station (e.g., such as BS 134) is an example of a radio access network (RAN) node within a wireless network. A BS (or a RAN node) may be or may include (or may alternatively be referred to as), e.g., an access point (AP), a gNB, an eNB, or portion thereof (such as a centralized unit (CU) and / or a distributed unit (DU) in the case of a split BS or split gNB), or other network node.

[0022] Some functionalities of the communication network may be carried out, at least partly, in a central / centralized unit, CU, (e.g., server, host or node) operationally coupled to distributed unit, DU, (e.g., a radio head / node). Thus, 5G networks architecture may be based on a so-called CU-DU split. The gNB-CU (central node) may control a plurality of spatially separated gNB-DUs, acting at least as transmit / receive (Tx / Rx) nodes. In some embodiments, however, the gNB-DUs (also called DU) may comprise e.g., a radio link control (RLC), medium access control (MAC) layer and a physical (PHY) layer, whereas the gNB-CU (also called a CU) may comprise the layers above RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) and an internet protocol (IP) layers. Other functional splits are possible too.

[0023] According to an illustrative example, a BS node (e.g., BS, eNB, gNB, CU / DU, . . .) or a radio access network (RAN) may be part of a mobile telecommunicationsystem. A RAN (radio access network) may include one or more BSs or RAN nodes that implement a radio access technology, e.g., to allow one or more UEs to have access to a network or core network (CN). Thus, for example, the RAN (RAN nodes, such as BSs or gNBs) may reside between one or more user devices or UEs and a core network. According to an example embodiment, each RAN node (e.g., BS, eNB, gNB, CU / DU, . . .) or BS may provide one or more wireless communication services for one or more UEs or user devices, e.g., to allow the UEs to have wireless access to a network, via the RAN node. Each RAN node or BS may perform or provide wireless communication services, e.g., such as allowing UEs or user devices to establish a wireless connection to the RAN node, and sending data to and / or receiving data from one or more of the UEs. For example, after establishing a connection to a UE, a RAN node or network node (e.g., BS, eNB, gNB, CU / DU, . . .) may forward data to the UE that is received from a network or the core network, and / or forward data received from the UE to the network or core network. RAN nodes or network nodes (e.g., BS, eNB, gNB, CU / DU, . . .) may perform a wide variety of other wireless functions or services, e.g., such as broadcasting control information (e.g., such as system information or on-demand system information) to UEs, paging UEs when there is data to be delivered to the UE, assisting in handover of a UE between cells, scheduling of resources for uplink data transmission from the UE(s) and downlink data transmission to UE(s), sending control information to configure one or more UEs, and the like. These are a few examples of one or more functions that a RAN node or BS may perform.

[0024] A user device or user node (user terminal, user equipment (UE), mobile terminal, handheld wireless device, etc.) may refer to a portable computing device that includes wireless mobile communication devices operating either with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: a mobile station (MS), a mobile phone, a cell phone, a smartphone, a personal digital assistant (PDA), a handset, a device using a wireless modem (alarm or measurement device, etc.), a laptop and / or touch screen computer, a tablet, a phablet, a game console, a notebook, a vehicle, a sensor, and a multimedia device, as examples, or any other wireless device. It should be appreciated that a user device may also be (or may include) a nearly exclusive uplink only device, of which an example is a camera or video camera loading images or video clips to a network. Also, a user node may include a user equipment (UE), a user device, a user terminal, a mobile terminal, a mobile station, a mobile node, asubscriber device, a subscriber node, a subscriber terminal, or other user node. For example, a user node may be used for wireless communications with one or more network nodes (e.g., gNB, eNB, BS, AP, CU, DU, CU / DU) and / or with one or more other user nodes, regardless of the technology or radio access technology (RAT). In LTE (as an illustrative example), core network 150 may be referred to as Evolved Packet Core (EPC), which may include a mobility management entity (MME) which may handle or assist with mobility / handover of user devices between BSs, one or more gateways that may forward data and control signals between the BSs and packet data networks or the Internet, and other control functions or blocks. Other types of wireless networks, such as 5G (which may be referred to as New Radio (NR)) may also include a core network.

[0025] In addition, the techniques described herein may be applied to various types of user devices or data service types, or may apply to user devices that may have multiple applications running thereon that may be of different data service types. New Radio (5G) development may support a number of different applications or a number of different data service types, such as for example: machine type communications (MTC), enhanced machine type communication (eMTC), Internet of Things (loT), and / or narrowband loT user devices, enhanced mobile broadband (eMBB), and ultra-reliable and low-latency communications (URLLC). Many of these new 5G (NR) - related applications may require generally higher performance than previous wireless networks.

[0026] loT may refer to an ever-growing group of objects that may have Internet or network connectivity, so that these objects may send information to and receive information from other network devices. For example, many sensor type applications or devices may monitor a physical condition or a status and may send a report to a server or other network device, e.g., when an event occurs. Machine Type Communications (MTC, or Machine to Machine communications) may, for example, be characterized by fully automatic data generation, exchange, processing and actuation among intelligent machines, with or without intervention of humans. Enhanced mobile broadband (eMBB) may support much higher data rates than currently available in LTE.

[0027] Ultra-reliable and low-latency communications (URLLC) is a new data service type, or new usage scenario, which may be supported for New Radio (5G) systems. This enables emerging new applications and services, such as industrial automations, autonomous driving, vehicular safety, e-health services, and so on. 3 GPP targets in providing connectivity with reliability corresponding to block error rate (BLER) of 10-5and up to 1 ms U-Plane (user / data plane) latency, by way of illustrative example. Thus, for example, URLLC user devices / UEs may require a significantly lower block error rate than other types of user devices / UEs as well as low latency (with or without requirement for simultaneous high reliability). Thus, for example, a URLLC UE (or URLLC application on a UE) may require much shorter latency, as compared to an eMBB UE (or an eMBB application running on a UE).

[0028] The techniques described herein may be applied to a wide variety of wireless technologies or wireless networks, such as 5G (New Radio (NR)), cmWave, and / or mmWave band networks, loT, MTC, eMTC, eMBB, URLLC, 6G, etc., or any other wireless network or wireless technology. These example networks, technologies or data service types are provided only as illustrative examples.

[0029] A user device (or UE) may measure various signals and may transmit one or more measurement reports to the network. For example, a UE may measure reference signals received from one or more network nodes (e.g., gNBs or DUs), including channel state information-reference signals (CSLRSs) and / or synchronization signal block (SSB) reference signals, demodulation references signals, and / or other reference signals. Based on received reference signals, the UE may measure various signal parameters, e.g., such as reference signal received power (RSRP), reference signal received quality (RSRQ), signal to interference plus noise ratio (SINR), received signal strength indicator (RSSI), or other signal parameter.

[0030] The PHY (physical) layer may refer to layer 1 (LI) and MAC (media access control) may refer to layer 2 (L2). RSRP, RSRQ, SINR and RSSI are signal quantities measured at layer 1 (LI). The UE may send LI measurement reports (e.g., CSLRS reports, which include measurements of one or more signal parameters for one or more cells) to a gNB, source DU or serving cell. These LI measurement reports may be sent periodically, for example, or aperiodically. L1 / L2 measurement reports may include no averaging or filtering of measurement values or may include less averaging or filtering than what is performed for L3 measurement reports. LI (or L1 / L2) measurement reports may be transmitted by a UE to a serving network node or source DU and may cause the network node to trigger or initiate a L1 / L2 triggered mobility (LTM) handover of the UE to another cell. LI measurements (e.g., RSRP RSRQ, RSSI) may be provided or reported periodically to the DU (MAC / PHY).

[0031] In an example, sounding reference signal (SRS) transmissions and non-zero power (NZP)-CSI-RS measurements may be used for assessing the channel quality, performing measurements related to beam management and mobility, and / or the like. For example, the CSI components may include at least one of the following: channel quality information (CQI), precoding matrix indicator (PMI), CSI-RS resource indicator (CRI), synchronization signal SS / PBCH resource block indicator (SSBRI), layer indicator (LI), rank indicator (RI), Ll-RSRP, and / or the like.

[0032] A configured NZP-CSLRS resource may correspond to up to 32 NZP-CSLRS antenna ports in NR. For example, there may be up to 32 different antenna ports multiplexed in time and frequency within the overall CSI-RS resource.

[0033] In wireless communications, an antenna port may represent a unique logical interface through which signals may be transmitted or received by a physical antenna or a group of antennas. For 5G NR, the use of different antenna ports may enable various transmission and reception scenarios, allowing for advanced functionalities like beamforming, MIMO (Multiple Input Multiple Output), and more.

[0034] In an example, the UE may use antenna ports associated with the reference signal resource(s) for channel estimation for downlink transmissions and for determining related channel state information (CSI). In other words, each individual downlink transmission of reference signal or channel may be carried out by using a specific antenna port, the identity of which is known to the UE.

[0035] In an example, a structure in the antenna port numbering may be used such that antenna ports for different purposes have numbers in different ranges. For example, downlink antenna ports starting with 1000 may be used for PDSCH. Different transmission layers for PDSCH can use antenna ports in this series, for example 1000 and 1001 for a two-layer PDSCH transmission. In an example, downlink antenna ports in the 3000 series may be used for the CSI-RS.

[0036] In an example, a receiver of a UE may include a low noise amplifier (LNA). The LNA may be employed by the receiver to amplify a low power signal received by an antenna. An amplifier may introduce additional noise, and therefore, the LNA may be designed to reduce or minimize any additional noise and thus avoid degradation of signal to noise ratio (SNR).

[0037] In an example, a configuration parameter of the LNA may determine a gain of the LNA, an output power of the LNA, and / or the like. For example, the gain may includea power gain that is based on a ratio of the output power to the input power of the LNA. In another example, the gain may include a voltage gain wherein the voltage gain is based on a ratio of the output voltage to the input voltage of the LNA. In another example, the gain may include a current gain wherein the current gain is based on a ratio of the output current to the input current of the LNA.

[0038] In an example, a design parameter of the LNA may be a noise figure (NF) and / or a noise factor (F). The noise figure (NF) and / or the noise factor (F) may be used to indicate degradation of the signal-to-noise ratio (SNR) that is caused by components in different stages of the LNA (circuit). For example, the noise factor may be determined based on a ratio of input SNR to the output SNR. The NF may represent the noise factor (F) in decibels (dB).

[0039] In an example, gain control of the LNA may be performed by using an automatic gain control (AGC) mechanism. AGC may ensure that the signal level at the analog to digital convertor (ADC) input is within dynamic range required by ADC to maintain good signal quality (e.g., to maintain good signal-to-interference plus noise ratio (SINR)) after the analog-to-digital conversion, e.g., ADC’s quantization error or saturation is minimized). In general, the operation of the AGC (or AGC algorithm) will continuously monitor the received signal levels in the RF receiver front-end, compare the signal level to predefined thresholds and adjust the receiver gain accordingly, e.g., for each OFDM symbol of the received positioning reference signals. For instance, if the received signal exceeds the accepted ADC’s max threshold signal levels (or the received signal power or amplitude is greater than a threshold), the AGC (or AGC algorithm) will attenuate the receiver gain stage (causing the amplitude or power of the received signal to decrease), and vice versa. If the received signal is weak (e.g., signal amplitude or power is less than a threshold), the AGC will boost or increase the receiver gain stage (causing the amplitude of the received signal to increase).

[0040] In an example, when the AGC gain level is changed, a phase shift may be induced or caused by the AGC. As a result, changes of AGC configurations over one or more time units (e.g., one or more time slots, one or more symbols, a plurality of time slots, or a plurality of symbols) may cause phase incoherency and / or amplitude incoherency at the receiver of the UE.

[0041] In an example, coherence may be maintained in phase and / or amplitude domain(s). Phase coherence between two signals may be achieved or exists when aconstant phase difference exists between the two antenna ports (e.g., same or different) of reference signal resource(s) associated with different time occasions or antenna ports of resources associated with signals associated with different time occasions, or when a phase difference between the two antenna ports of reference signal resource(s) of the same frequency is within a tolerance range in phase, e.g., ± 22.5 or 45 degrees or any predefined phase range in degrees or radians. Thus, for example, the phase difference of the two antenna ports of reference signal resources associated with different time occasions or antenna ports of resources associated with signals associated with different time occasions should be within a tolerance range to be considered phase coherent over period of time defined by two different time occasions.

[0042] In an example embodiment, in order for multiple signals to be phase coherent over one or more time units, these multiple signals should have either a zero phase difference, or a phase difference that is within a tolerance range, such as within a maximum phase deviation.

[0043] Amplitude coherence may be achieved or exists when a constant amplitude difference exists between two antenna ports (same or different) of reference signal resource(s) associated with different time occasion or antenna ports of resources associated with signals associated with different time occasions, or when an amplitude difference between the two antenna ports of reference signal resource(s) of the same frequency is within a tolerance range in amplitude, e.g., ± 2 or 4 decibels (dB) or any predefined amplitude range in dB or dBm. Thus, for example, the two antenna ports of reference signal resources associated with different time occasions or antenna ports of resources associated with signals associated with different time occasions should be within a tolerance range to be considered amplitude coherent over period of time defined by two different time occasions.

[0044] In an example embodiment, in order for multiple signals to be amplitude coherent over one or more time units, these multiple signals should have either a zero amplitude difference, or an amplitude difference that is within a tolerance range, such as within a maximum amplitude deviation.

[0045] In an example, signals (e.g., waves, electromagnetic waves, acoustic waves, and / or the like) may face distortions or disturbances due to the dynamics of radio channels (e.g., reflection, refraction, scattering, diffraction, and / or the like) and may lead to changes in phase or amplitude. In such scenarios, the relative phase, phase difference, relativeamplitude, amplitude difference may not be constant and hence the disturbed signals are no longer coherent in phase or amplitude - or become phase incoherent or amplitude incoherent. In another example, the relative phase or amplitude between the two signals may vary with time. Therefore, in such cases, the segments of time where the phase or amplitude difference is constant or within a tolerance range may be referred to as phase coherent segments or amplitude coherent segments. In an example implementation, to the extent there is a UE receiver incoherency in amplitude or phase of multiple signals (e.g., phase or amplitude of the signals varies by more than a maximum deviation), one or more parameters of configurations of the UE hardware (e.g., LNA or AGC) may be adjusted or configured to compensate for the UE receiver antenna port incoherency. In other words, antenna port incoherency may occur or exist when phase difference or amplitude difference varies between receiver antenna ports (same or different) by more than a tolerance range over one or more time units (e.g., over a time period). In an example, the one or more time units may include one or more time slots, one or more symbols, a plurality of time slots, a plurality of symbols, and / or the like.

[0046] FIG. 2 is a diagram illustrating a multiple input multiple output (MIMO) transmission. In an example embodiment, the MIMO transmission may include a technique to increase the data throughput by using multiple transmitter antenna(s) and multiple receiver antenna(s). For example, in the MIMO transmission, multiple (independent) data streams may be transmitted simultaneously to achieve higher data throughput in comparison to a single input single output (SISO) transmission. In an example embodiment, a data stream may correspond to a layer or an antenna port of the MIMO transmission.

[0047] In an example, to address an issue of coverage, and to achieve higher downlink spectrum efficiency, larger antenna arrays for single transmission point transmissions with an increased number of antennas may be beneficial, due to new available frequency bands (e.g., 6.425-7.125 GHz). Existing implementations do not support larger antenna arrays with large number of CSI-RS ports for CSI measurement and reporting. As a result, it is advantageous to increase the number of ports for CSI reporting (e.g., up to 128 CSI-RS ports or antenna ports for CSI-RS measurement).

[0048] Therefore, to enhance coverage where higher frequency bands (such as 6.425 - 7.125 GHz) are used, larger antenna arrays may be employed. To support larger antenna arrays for 128 antenna port (AP) CSI-RS configurations (e.g., 128 AP non-zero powerCSI-RS (NZP-CSI-RS)), an example implementation may include using four of 32 antenna port CSI-RS(s) distributed across consecutive slots.

[0049] FIG. 3 is a diagram illustrating an example 128-AP NZP-CSI-RS resource configuration with four 32-AP NZP-CSI-RSs distributed across two consecutive slots. When multiple NZP-CSI-RS resources are distributed over consecutive slots, a problem may arise when the received signal phase or amplitude is not coherent across the two consecutive slots (or one or more time units).

[0050] As another example, a problem may also arise when the network (e.g., network node) is unable to determine whether the UE is capable of receiving one or more signals in a coherent manner (e.g., over consecutive slots). As a result, the network may be unable to provide proper configuration of reference signal resources to the UE. In other words, the UE capability (e.g., to maintain receiver phase coherence or amplitude coherence of one or more received signals in one or more time units) may not be known to the network and as a result, the network may not provide proper configuration of reference signal resources to the UE.

[0051] Therefore, techniques are provided to maintain receiver phase coherency and / or amplitude coherency at the UE, and / or indicating a capability of the UE to the network (e.g., network node) for the UE to maintain receiver phase coherence and / or amplitude coherence, which may be beneficial to ensure reception of proper configuration of reference signal resources. The UE may indicate to the gNB the UE receiver phase and / or amplitude coherence capability, so as to enable the gNB to know (or determine) the capabilities of the UE with respect to receiver amplitude and / or phase coherency, such as how long the UE may maintain receiver phase coherency or amplitude coherency.Based on the indication, e.g., capability indication / information from the UE, the gNB may configure reference signal configuration(s) (e.g., NZP-CSI-RS) for measurements (e.g., for downlink CSI measurements), so as to enable the UE to provide accurate parameter estimates and corresponding CSI report. Also, for example, by the UE maintaining receiver amplitude coherency and / or phase coherency at the UE over one or more time units on which one or more parameters of CSI-RS are measured, the UE may obtain more accurate parameter estimates for a CSI report.

[0052] Example embodiments are directed to enhancement of signaling between the UE and the network (e.g., via the air interface) to enable CSI acquisition and measurement of reference signals while maintaining receiver phase and / or amplitude coherence. In anexample, the UE may be required to maintain downlink receiver phase and / or amplitude coherence across one or more time units, such as across a plurality of consecutive symbols or across a plurality of consecutive slots. In other words, the UE may be capable of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in (or across) one or more time units (e.g., one or more time slots, one or more symbols, a plurality of time slots, or a plurality of symbols). To achieve the receiver phase coherence or receiver amplitude coherence, the UE may be required (or may be configured) to use the same radio frequency (RF) hardware configuration of a LNA and AGC to ensure that phase and / or amplitude of the received signals over the one or more time units are coherent. In another example, the UE may adjust the LNA and the AGC configurations based on an algorithm to ensure that the receiver phase and / or receiver amplitude of the received signals over the one or more time units are coherent. For example, the algorithm for adjusting the configurations of the LNA and the AGC may take into account dynamics of channel conditions. In an example, each channel estimation sample may have characteristics or imperfections in terms of amplitude and / or phase (e.g., imperfections or variations in amplitude or phase introduced by transmission (TX) chain, radio channel, and the receiver chain e.g., including AGC, analog components, ADC, and / or the like). In an example implementation, the AGC may adjust one or more parameters according to an average received signal level before the ADC stage to compensate for the imperfections.

[0053] Therefore, example embodiments are directed to enable the UE (e.g., that is capable of maintaining receiver phase coherence or receiver amplitude coherence of one or more received signals in or across one or more time units) to indicate to the network (e.g., network node, gNB, and / or the like) that the UE is capable of maintaining at least one of the receiver phase coherence or the amplitude coherence of the one or more received signals in the one or more time units. Subsequently, the UE may receive from the network node, a configuration of reference signal resources based on the UE capability. Therefore, the UE may receive reference signals via the configured reference signal resources. The UE may acquire (e.g., determine, obtain, and / or the like) downlink CSI, based on measurements on the reference signals (e.g., based on various UE parameter measurements of the received CSLRS signals received by the UE via the configured reference signal resources). In an example, the downlink CSI may be associated with antenna ports of the configured reference signal resources over the one or more time units.As a result, the UE may acquire the downlink CSI while maintaining at least one of the receiver phase coherence or the receiver amplitude coherence over the one or more time units.

[0054] FIG. 4 is a diagram illustrating an aspect of an example embodiment. At step 1, The UE 410 may indicate a UE 410 capability indication to a gNB 420. The capability indication may be receiver phase coherency capability information and / or receiver amplitude coherency information (e.g., information indicating the UE’s capability to maintain receiver amplitude and / or phase coherency over a time period or over one or more time units). The example shown in FIG. 4 is shown with respect to UE 410 receiver phase coherency, but may also be provided or performed with respect to UE 410 receiver amplitude coherency. The capability information may be transmitted by the UE 410 (and received by the gNB 420 or network node 420) via radio resource control (RRC) signaling, such as a RRC message. In an example, the capability indication or the capability information may be an information element (IE) included in a RRC message sent or transmitted by the UE 410 to the gNB 420 (e.g., the network node 420). In an example, the UE 410 capability information may include information about UE 410 receiver amplitude and / or phase coherency in one or more time units, e.g., the UE 410 capability indication may indicate a time period such as a number of symbols or time slots for which the UE 410 is capable of maintaining UE 410 receiver amplitude coherence and / or UE 410 receiver phase coherence (e.g., with predefined (or specific) sub-carrier spacing or with default sub-carrier spacing). In an example implementation, the UE 410 may transmit to the gNB 420 or the network node 420, a capability indication that indicates the UE 410 is capable of maintaining at least one of the receiver phase coherence or the receiver amplitude coherence of the one or more received signals in the one or more time units. In an example, the one or more time units may include one or more time slots, one or more symbols, a plurality of time slots, a plurality of symbols, and / or the like. In an example implementation, the capability indication may include at least one of: a time value indicating a duration for which a receiver of the UE 410 can maintain phase coherence, a time value indicating a duration for which the receiver of the UE 410 can maintain amplitude coherence, a reference signal type (such as NZP-CSI-RS, a phase tracking reference signal (PTRS), a demodulation reference signal (DMRS), and / or the like), a maximum amplitude deviation for which the receiver of the UE can maintain the amplitude coherence, a number of receiver antenna port groups, a phase rotation value ora maximum phase deviation (or a tolerance range) for which the receiver of the UE can maintain the phase coherence, and / or the like. In an example, the receiver antenna port group may include a set of receiving antenna port(s) or logical receiving antenna port(s) which may be associated with one or more physical antennas (or antenna arrangements). For example, the antenna arrangements may be one or more antenna elements, antenna connectors, antenna radiators, antenna panels, and / or the like.

[0055] In an example, the phase rotation value or the maximum phase deviation may be indicated by a vector of bits, wherein each bit of the vector is associated with a phase rotation value. As an example, a predefined set of maximum phase rotation values may be indicated. For example, when the indication is implemented by a bit vector with length of L, the indication may support different possible phase rotation values equal to L. As an example, if L=4, the following example association may be indicated / defined:- Most significant bit (MSB) of the 4-bit-vector may be associated with 5 degree / radians of phase shift.- MSB -1 of the 4-bit-vector may be associated with 10 degree / radians of phase shift.- MSB -2 of the 4-bit-vector may be associated with 15 degree / radians of phase shift.- MSB -3 of the 4-bit-vector may be associated with 20 degree / radians of phase shift.

[0056] In an example, the value of the maximum amplitude deviation may be indicated by a vector of bits, wherein each bit of the vector is associated with a maximum amplitude deviation value. As an example, a predefined set of maximum amplitude deviation values may be indicated. For example, when the indication is implemented by a bit vector with length of Q, the indication may support different possible amplitude deviation values equal to Q. As an example, if Q=2, the following example association may be indicated / defined:- Most significant bit (MSB) of the 2-bit-vector may be associated with 2 dB of amplitude deviation.- MSB -1 of the 2-bit-vector may be associated with 4 dB of amplitude deviation.

[0057] In an example, the capability indication may include one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information may be associated with a reference signal type. For example, the reference signal type may include at least one of a non-zero power channel state information reference signal (NZP-CSI-RS), a phase tracking reference signal (PTRS), a demodulation reference signal (DMRS), and / or the like.

[0058] In an example embodiment, the capability indication may include one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information may be associated with a set of receiver antenna port groups wherein the set of receiver antenna port groups may include a plurality of logical receiving antenna ports associated with a plurality of physical antennas. Thus, for example, one or more of the receiver phase coherence capability information and / or receiver amplitude coherence information may be associated with a set of (or a plurality of) antenna ports.

[0059] In an example embodiment, the capability indication may include at least one of: a number of time domain symbols of the one or more received signals for which the receiver phase coherence or receiver amplitude coherence can be maintained by the UE, a number of reference signal receptions for which the receiver phase coherence or receiver amplitude coherence can be maintained, and / or the like. In another example, the capability indication may include a maximum number of symbol difference indicating a maximum supported time difference between a first received symbol associated with the reference signal, e.g., NZP-CSI-RS resource, and the last received reference signal (e.g., NZP- CSI-RS) resource within the NZP-CSI-RS resource, such that the UE can maintain receiver phase and / or amplitude coherence over this time period from the first reference signal through the last reference signal. For example, the UE may indicate that the maximum number of symbol difference is 10 symbols within NZP-CSI-RS resource set. Then, the UE may be configured with 64 NZP-CSI-RS resources, e.g., two different resources where each NZP-CSI-RS resource has (or is associated with) 32 antenna ports over 4 different consecutive symbols. The UE may be configured with two NZP-CSI-RS resources, e.g., CSI resource indices 0 and 1, CRI#0, CRI#1, respectively, within NZP-CSI-RS resource set. As a result, the first resource, CRI#0, with 32-AP may be configured to start from symbol position 0 up to symbol position 3 and the second resource, CRI#1, may be configured from symbol position 4 up to symbol position 7. Since the UE indicated the maximum number of symbol difference to be 10, the network may assume that the UE may (or can) maintain coherency in phase and / or amplitude over 10 symbols from the reception of the first NZP-CSI-RS resource.

[0060] At step 2 of FIG. 4, the gNB 420 may determine reference signal resource configurations for the UE 410 that supports high number of NZP-CSI-RS antenna ports. In an example, the determining may be based on the received capability indication fromthe UE 410 at step 1. At step 3, the UE 410 may receive a configuration of reference signal resources from the gNB 420. In other words, the gNB 420 may configure (e.g., via RRC signaling) NZP-CSI-RS resource set(s) by transmitting configuration of NZP-CSI-RS resources for high number of antenna ports. At step 4, the gNB 420 may transmit periodic / semi-persistent / aperiodic NZP-CSI-RS resources for DL CSI acquisition with high number of antenna ports over one or more time units or a plurality of time units. At step 5, the UE 410 may receive reference signals via the configured reference signal resources. For example, the UE 410 may receive from the gNB 420, the reference signals via NZP-CSI-RS resources over a plurality of time units (e.g., multiple symbols and / or time slots). At step 6, the UE 410 may maintain receiver phase coherency (e.g., by adjusting or maintaining same RF hardware configurations (e.g., LNA and AGC parameters)) over multiple symbols and / or time slots. In an example, the UE 410 may acquire downlink CSI associated with antenna ports of the configured reference signal resources over the one or more time units, based on measurements on the reference signals. In an example, the UE may acquire the downlink CSI (including measuring one or more parameters of the received reference signals over the one or more time units) while maintaining at least one of the receiver phase coherence or the receiver amplitude coherence over the one or more time units. At step 7, the UE 410 may determine CSI report parameters (e.g., PMI, RI, CQI, and / or the like) for the acquired CSI based on received NZP-CSI-RS (resources) over multiple symbols and / or time slots. At step 8, the UE 410 may transmit to the gNB 420, a CSI report including the CSI report parameters based on the acquired CSI. In other words, the UE 410 may transmit to the gNB 420, the CSI report (e.g., via PUCCH ) associated with downlink CSI acquisition.

[0061] In an example embodiment, the gNB 420 may apply the indicated maximum phase deviation and / or the maximum amplitude deviation information for downlink transmissions to the UE 410. As a result, the downlink transmission from the gNB 420 associated with at least one of the reference signal resources, data channel resources, or control channel resources may be coherent in phase or amplitude within a tolerance range based on the capability indication transmitted / indicated by the UE 410 to the gNB 420. In an example, the reference signal resources may include at least one of a non-zero power channel state information received signal (NZP-CSI-RS) resource, a phase tracking reference signal (PTRS) resource, or a demodulation reference signal (DMRS) resource. In an example, the data channel resources may include a physical downlink shared channel(PDSCH). In an example, the control channel resources may include at least one of a physical downlink control channel (PDCCH) or a physical broadcast channel (PBCH). In other words, the gNB 420 may compensate for the UE 410 phase rotation and / or amplitude deviation (tolerance) and apply the indicated maximum phase deviation and / or the maximum amplitude deviation information while determining downlink transmission associated with reference signal resources (e.g., NZP-CSI-RS, PTRS, DMRS) and / or data channel resources (e.g., PDSCH) and / or control channel resources (e.g., PDCCH, PBCH).

[0062] FIG. 5 is a flow chart illustrating operation of an apparatus (e.g., which may be a UE or user device, or other apparatus) according to an example embodiment. Operation 520 includes receiving, by a user device, capable of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in one or more time units, from a network node, a configuration of reference signal resources. Operation 520 includes receiving reference signals via the configured reference signal resources. Operation 530 includes acquiring, based on measurements on the reference signals, downlink channel state information (CSI) associated with antenna ports of the configured reference signal resources over the one or more time units, while maintaining at least one of the receiver phase coherence or the receiver amplitude coherence over the one or more time units.

[0063] With respect to the method of FIG. 5, the method may further include: transmitting, by the user device to the network node, a capability indication that indicates the user device is capable of maintaining at least one of the receiver phase coherence or the amplitude coherence of the one or more received signals in the one or more time units.

[0064] With respect to the method of FIG. 5, the method may further include: wherein the one or more time units comprises at least one of: one or more symbols; or one or more time slots.

[0065] With respect to the method of FIG. 5, the method may further include: transmitting, a CSI report based on the acquired CSI.

[0066] With respect to the method of FIG. 5, the method may further include: wherein the capability indication comprises at least one of: a time value indicating a duration for which a receiver of the user device can maintain phase coherence; a time value indicating a duration for which the receiver of the user device can maintain amplitude coherence; a reference signal type; a maximum amplitude deviation for which the receiver of the user device can maintain the amplitude coherence; number of receiving antenna port groups; ora phase rotation value or a maximum phase deviation for which the receiver of the user device can maintain the phase coherence.

[0067] With respect to the method of FIG. 5, the method may further include: wherein the phase rotation value or the maximum phase deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a phase rotation value.

[0068] With respect to the method of FIG. 5, the method may further include: wherein a value of the maximum amplitude deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a maximum amplitude deviation value.

[0069] With respect to the method of FIG. 5, the method may further include: wherein the capability indication comprises one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information is associated with a reference signal type.

[0070] With respect to the method of FIG. 5, the method may further include: wherein the reference signal type comprises at least one of a non-zero power channel state information reference signal (NZP-CSI-RS), a phase tracking reference signal (PTRS), or a demodulation reference signal (DMRS).

[0071] With respect to the method of FIG. 5, the method may further include: wherein the capability indication comprises one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information is associated with a set of receiver antenna port groups wherein the set of receiver antenna port groups comprise a plurality of logical receiving antenna ports associated with a plurality of physical antennas.

[0072] With respect to the method of FIG. 5, the method may further include: wherein the capability indication comprises at least one of: a number of time domain symbols of the one or more received signals for which the receiver phase coherence or amplitude coherence can be maintained; or a number of reference signal receptions for which the receiver phase coherence or amplitude coherence can be maintained.

[0073] With respect to the method of FIG. 5, the method may further include: wherein the received reference signals from the network node are coherent in phase or amplitude within a tolerance range based on the capability indication transmitted by the user device.

[0074] With respect to the method of FIG. 5, the method may further include: wherein a downlink transmission from the network node associated with at least one of thereference signal resources, data channel resources, or control channel resources is coherent in phase or amplitude within a tolerance range based on the capability indication transmitted by the user device.

[0075] With respect to the method of FIG. 5, the method may further include: wherein the reference signal resources comprise at least one of a non-zero power channel state information received signal (NZP-CSI-RS) resource, a phase tracking reference signal (PTRS) resource, or a demodulation reference signal (DMRS) resource.

[0076] With respect to the method of FIG. 5, the method may further include: wherein the data channel resources comprise a physical downlink shared channel (PDSCH).

[0077] With respect to the method of FIG. 5, the method may further include: wherein the control channel resources comprise at least one of a physical downlink control channel (PDCCH) or a physical broadcast channel (PBCH).

[0078] With respect to the method of FIG. 5, the method may further include: wherein the reference signals resources are for downlink reception.

[0079] With respect to the method of FIG. 5, the method may further include: wherein a receiver of the user device is configured to maintain at least one of the receiver phase coherence or the amplitude coherence in the one or more time units.

[0080] With respect to the method of FIG. 5, the method may further include: wherein the user device is capable of maintaining a receiver phase coherence of the one or more received signals in the one or more time units; and the acquiring of the downlink CSI is based on the measurements on the reference signals while maintaining the receiver phase coherence over the one or more time units.

[0081] With respect to the method of FIG. 5, the method may further include: wherein the user device is capable of maintaining a receiver amplitude coherence of the one or more received signals in the one or more time units; and the acquiring of the downlink CSI is based on the measurements on the reference signals while maintaining the receiver amplitude coherence over the one or more time units.

[0082] With respect to the method of FIG. 5, the method may further include: wherein the one or more time units comprise a plurality of time units, wherein the plurality of time units comprises at least one of: a plurality of symbols; or a plurality of time slots.

[0083] FIG. 6 is a flow chart illustrating operation of an apparatus (e.g., which may be a gNB or network node, or other apparatus) according to an example embodiment. Operation 610 includes receiving, by a network node from a user device, a capabilityindication of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in one or more time units. Operation 620 includes transmitting, based on the capability indication, a configuration of reference signal resources. Operation 630 includes transmitting reference signals via the configured reference signal resources.

[0084] With respect to the method of FIG. 6, the method may further include: receiving a channel state information (CSI) measurement report that is based on measurements of the reference signals performed by the user device while maintaining at least one of the receiver phase coherence or amplitude coherence over the one or more time units.

[0085] With respect to the method of FIG. 6, the method may further include: wherein the transmitted reference signals are coherent in phase or amplitude within a tolerance range based on the capability indication received from the user device.

[0086] With respect to the method of FIG. 6, the method may further include: wherein the capability indication comprises at least one of: a time value indicating a duration for which a receiver of the user device can maintain phase coherence; a time value indicating a duration for which the receiver of the user device can maintain amplitude coherence; a reference signal type; a maximum amplitude deviation for which the receiver of the user device can maintain the amplitude coherence; number of receiving antenna port groups; or a phase rotation value or a maximum phase deviation for which the receiver of the user device can maintain the phase coherence.

[0087] With respect to the method of FIG. 6, the method may further include: wherein the phase rotation value or the maximum phase deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a phase rotation value.

[0088] With respect to the method of FIG. 6, the method may further include: wherein a value of the maximum amplitude deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a maximum amplitude deviation value.

[0089] With respect to the method of FIG. 6, the method may further include: wherein the capability indication comprises one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information is associated with a reference signal type.

[0090] With respect to the method of FIG. 6, the method may further include: wherein the reference signal type comprises at least one of a non-zero power channel state information reference signal (NZP-CSI-RS), a phase tracking reference signal (PTRS), or a demodulation reference signal (DMRS).

[0091] With respect to the method of FIG. 6, the method may further include: wherein the capability indication comprises at least one of: a number of time domain received symbols deviation for which the receiver phase coherence or amplitude coherence can be maintained; or a number of reference signal receptions for which the receiver phase coherence or amplitude coherence can be maintained.

[0092] Some examples will now be described, based on the description and figures provided herein.

[0093] Example Al. An apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, by the apparatus, capable of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in one or more time units, from a network node, a configuration of reference signal resources; receive, reference signals via the configured reference signal resources; and acquire, based on measurements on the reference signals, downlink channel state information (CSI) associated with antenna ports of the configured reference signal resources over the one or more time units, while maintaining at least one of the receiver phase coherence or the amplitude coherence over the one or more time units.

[0094] Example A2. The apparatus of example Al, further including transmitting, by the apparatus to the network node, a capability indication that indicates the apparatus is capable of maintaining at least one of the receiver phase coherence or the amplitude coherence of the one or more received signals in the one or more time units.

[0095] Example A3. The apparatus of example Al, wherein the one or more time units includes at least one of: one or more symbols; or one or more time slots.

[0096] Example A4. The apparatus of example Al, wherein the apparatus is further caused to transmit a CSI report based on the acquired CSI.

[0097] Example A5. The apparatus of example A2, wherein the capability indication includes at least one of: a time value indicating a duration for which a receiver of the apparatus can maintain phase coherence; a time value indicating a duration for which the receiver of the apparatus can maintain amplitude coherence; a reference signal type; amaximum amplitude deviation for which the receiver of the apparatus can maintain the amplitude coherence; number of receiving antenna port groups; or a phase rotation value or a maximum phase deviation for which the receiver of the apparatus can maintain the phase coherence.

[0098] Example A6. The apparatus of example A5, wherein the phase rotation value or the maximum phase deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a phase rotation value.

[0099] Example A7. The apparatus of example A5, wherein a value of the maximum amplitude deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a maximum amplitude deviation value.

[0100] Example A8. The apparatus of example A2, wherein the capability indication includes one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information is associated with a reference signal type.

[0101] Example A9. The apparatus of example A8, wherein the reference signal type includes at least one of a non-zero power channel state information reference signal (NZP-CSI-RS), a phase tracking reference signal (PTRS), or a demodulation reference signal (DMRS).

[0102] Example A10. The apparatus of example A2, wherein the capability indication includes one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information is associated with a set of receiver antenna port groups wherein the set of receiver antenna port groups include a plurality of logical receiving antenna ports associated with a plurality of physical antennas.

[0103] Example Al l. The apparatus of example A2, wherein the capability indication includes at least one of: a number of time domain symbols of the one or more received signals for which the receiver phase coherence or amplitude coherence can be maintained; or a number of reference signal receptions for which the receiver phase coherence or amplitude coherence can be maintained.

[0104] Example A12. The apparatus of example A2, wherein the received reference signals from the network node are coherent in phase or amplitude within a tolerance range based on the capability indication transmitted by the apparatus.

[0105] Example Al 3. The apparatus of example A2, wherein a downlink transmission from the network node associated with at least one of the reference signal resources, data channel resources, or control channel resources is coherent in phase or amplitude within a tolerance range based on the capability indication transmitted by the apparatus.

[0106] Example A14. The apparatus of example A13, wherein the reference signal resources include at least one of a non-zero power channel state information received signal (NZP-CSI-RS) resource, a phase tracking reference signal (PTRS) resource, or a demodulation reference signal (DMRS) resource.

[0107] Example A15. The apparatus of example A13, wherein the data channel resources include a physical downlink shared channel (PDSCH).

[0108] Example A16. The apparatus of example A13, wherein the control channel resources include at least one of a physical downlink control channel (PDCCH) or a physical broadcast channel (PBCH).

[0109] Example Al 7. The apparatus of example Al, wherein the reference signals resources are for downlink reception.

[0110] Example A18. The apparatus of example Al, wherein a receiver of the apparatus is configured to maintain at least one of the receiver phase coherence or the amplitude coherence in the one or more time units.

[0111] Example Al 9. The apparatus of example Al wherein: the apparatus is capable of maintaining a receiver phase coherence of the one or more received signals in the one or more time units; and the acquiring of the downlink CSI is based on the measurements on the reference signals while maintaining the receiver phase coherence over the one or more time units.

[0112] Example A20. The apparatus of example Al, wherein: the apparatus is capable of maintaining a receiver amplitude coherence of the one or more received signals in the one or more time units; and the acquiring of the downlink CSI is based on the measurements on the reference signals while maintaining the receiver amplitude coherence over the one or more time units.

[0113] Example A21. The apparatus of example Al, wherein the one or more time units include a plurality of time units, wherein the plurality of time units includes at least one of: a plurality of symbols; or a plurality of time slots.

[0114] Example B 1. An apparatus including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause theapparatus at least to: receive, from a user device, a capability indication of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in one or more time units; transmit, based on the capability indication, a configuration of reference signal resources; and transmit, reference signals via the configured reference signal resources.

[0115] Example B2. The apparatus of example Bl, wherein the apparatus is further caused to receive a channel state information (CSI) measurement report that is based on measurements of the reference signals performed by the user device while maintaining at least one of the receiver phase coherence or amplitude coherence over the one or more time units.

[0116] Example B3. The apparatus of example Bl, wherein the transmitted reference signals are coherent in phase or amplitude within a tolerance range based on the capability indication received from the user device.

[0117] Example B4. The apparatus of example Bl, wherein the capability indication includes at least one of: a time value indicating a duration for which a receiver of the user device can maintain phase coherence; a time value indicating a duration for which the receiver of the user device can maintain amplitude coherence; a reference signal type; a maximum amplitude deviation for which the receiver of the user device can maintain the amplitude coherence; number of receiving antenna port groups; or a phase rotation value or a maximum phase deviation for which the receiver of the user device can maintain the phase coherence.

[0118] Example B5. The apparatus of example B4, wherein the phase rotation value or the maximum phase deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a phase rotation value.

[0119] Example B6. The apparatus of example B4, wherein a value of the maximum amplitude deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a maximum amplitude deviation value.

[0120] Example B7. The apparatus of example Bl, wherein the capability indication includes one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information is associated with a reference signal type.

[0121] Example B8. The apparatus of example B7, wherein the reference signal type includes at least one of a non-zero power channel state information reference signal(NZP-CSI-RS), a phase tracking reference signal (PTRS), or a demodulation reference signal (DMRS).

[0122] Example B9. The apparatus of example Bl, wherein the capability indication includes at least one of: a number of time domain received symbols deviation for which the receiver phase coherence or amplitude coherence can be maintained; or a number of reference signal receptions for which the receiver phase coherence or amplitude coherence can be maintained.

[0123] Example Cl. A method including: receiving, by a user device, capable of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in one or more time units, from a network node, a configuration of reference signal resources; receiving reference signals via the configured reference signal resources; and acquiring, based on measurements on the reference signals, downlink channel state information (CSI) associated with antenna ports of the configured reference signal resources over the one or more time units, while maintaining at least one of the receiver phase coherence or the amplitude coherence over the one or more time units.

[0124] Example C2. The method of example Cl, further including transmitting, by the user device to the network node, a capability indication that indicates the user device is capable of maintaining at least one of the receiver phase coherence or the amplitude coherence of the one or more received signals in the one or more time units.

[0125] Example C3. The method of example Cl, wherein the one or more time units includes at least one of: one or more symbols; or one or more time slots.

[0126] Example C4. The method of example Cl, further including transmitting, a CSI report based on the acquired CSI.

[0127] Example C5. The method of example C2, wherein the capability indication includes at least one of: a time value indicating a duration for which a receiver of the user device can maintain phase coherence; a time value indicating a duration for which the receiver of the user device can maintain amplitude coherence; a reference signal type; a maximum amplitude deviation for which the receiver of the user device can maintain the amplitude coherence; number of receiving antenna port groups; or a phase rotation value or a maximum phase deviation for which the receiver of the user device can maintain the phase coherence.

[0128] Example C6. The method of example C5, wherein the phase rotation value or the maximum phase deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a phase rotation value.

[0129] Example C7. The method of example C5, wherein a value of the maximum amplitude deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a maximum amplitude deviation value.

[0130] Example C8. The method of example C2, wherein the capability indication includes one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information is associated with a reference signal type.

[0131] Example C9. The method of example C8, wherein the reference signal type includes at least one of a non-zero power channel state information reference signal (NZP-CSI-RS), a phase tracking reference signal (PTRS), or a demodulation reference signal (DMRS).

[0132] Example CIO. The method of example C2, wherein the capability indication includes one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information is associated with a set of receiver antenna port groups wherein the set of receiver antenna port groups include a plurality of logical receiving antenna ports associated with a plurality of physical antennas.

[0133] Example Cl 1. The method of example C2, wherein the capability indication includes at least one of: a number of time domain symbols of the one or more received signals for which the receiver phase coherence or amplitude coherence can be maintained; or a number of reference signal receptions for which the receiver phase coherence or amplitude coherence can be maintained.

[0134] Example C12. The method of example C2, wherein the received reference signals from the network node are coherent in phase or amplitude within a tolerance range based on the capability indication transmitted by the user device.

[0135] Example C13. The method of example C2, wherein a downlink transmission from the network node associated with at least one of the reference signal resources, data channel resources, or control channel resources is coherent in phase or amplitude within a tolerance range based on the capability indication transmitted by the user device.

[0136] Example C14. The method of example C13, wherein the reference signal resources include at least one of a non-zero power channel state information received signal (NZP-CSI-RS) resource, a phase tracking reference signal (PTRS) resource, or a demodulation reference signal (DMRS) resource.

[0137] Example C15. The method of example C13, wherein the data channel resources include a physical downlink shared channel (PDSCH).

[0138] Example C16. The method of example C13, wherein the control channel resources include at least one of a physical downlink control channel (PDCCH) or a physical broadcast channel (PBCH).

[0139] Example Cl 7. The method of example Cl, wherein the reference signals resources are for downlink reception.

[0140] Example C18. The method of example Cl, wherein a receiver of the user device is configured to maintain at least one of the receiver phase coherence or the amplitude coherence in the one or more time units.

[0141] Example Cl 9. The method of example Cl wherein: the user device is capable of maintaining a receiver phase coherence of the one or more received signals in the one or more time units; and the acquiring of the downlink CSI is based on the measurements on the reference signals while maintaining the receiver phase coherence over the one or more time units.

[0142] Example C20. The method of example Cl, wherein: the user device is capable of maintaining a receiver amplitude coherence of the one or more received signals in the one or more time units; and the acquiring of the downlink CSI is based on the measurements on the reference signals while maintaining the receiver amplitude coherence over the one or more time units.

[0143] Example C21. The method of example Cl, wherein the one or more time units include a plurality of time units, wherein the plurality of time units includes at least one of: a plurality of symbols; or a plurality of time slots.

[0144] Example DI . A method including: receiving, by a network node from a user device, a capability indication of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in one or more time units; transmitting, based on the capability indication, a configuration of reference signal resources; and transmitting reference signals via the configured reference signal resources.

[0145] Example D2. The method of example DI, further including receiving a channel state information (CSI) measurement report that is based on measurements of the reference signals performed by the user device while maintaining at least one of the receiver phase coherence or amplitude coherence over the one or more time units.

[0146] Example D3. The method of example DI, wherein the transmitted reference signals are coherent in phase or amplitude within a tolerance range based on the capability indication received from the user device.

[0147] Example D4. The method of example DI, wherein the capability indication includes at least one of: a time value indicating a duration for which a receiver of the user device can maintain phase coherence; a time value indicating a duration for which the receiver of the user device can maintain amplitude coherence; a reference signal type; a maximum amplitude deviation for which the receiver of the user device can maintain the amplitude coherence; number of receiving antenna port groups; or a phase rotation value or a maximum phase deviation for which the receiver of the user device can maintain the phase coherence.

[0148] Example D5. The method of example D4, wherein the phase rotation value or the maximum phase deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a phase rotation value.

[0149] Example D6. The method of example D4, wherein a value of the maximum amplitude deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a maximum amplitude deviation value.

[0150] Example D7. The method of example DI, wherein the capability indication includes one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information is associated with a reference signal type.

[0151] Example D8. The method of example D7, wherein the reference signal type includes at least one of a non-zero power channel state information reference signal (NZP-CSI-RS), a phase tracking reference signal (PTRS), or a demodulation reference signal (DMRS).

[0152] Example D9. The method of example DI, wherein the capability indication includes at least one of: a number of time domain received symbols deviation for which the receiver phase coherence or amplitude coherence can be maintained; or a number ofreference signal receptions for which the receiver phase coherence or amplitude coherence can be maintained.

[0153] FIG. 7 is a block diagram of a wireless station or node (e.g., UE, user device, AP, BS, eNB, gNB, RAN node, network node, TRP, or other node) 1300 according to an example embodiment. The wireless station 1300 may include, for example, one or more (e.g., two as shown in FIG. 7) RF (radio frequency) or wireless transceivers 1302 A, 1302B, where each wireless transceiver includes a transmitter to transmit signals and a receiver to receive signals. The wireless station also includes a processor or control unit / entity (controller) 1304 to execute instructions or software and control transmission and receptions of signals, and a memory 1306 to store data and / or instructions.

[0154] Processor 1304 may also make decisions or determinations, generate frames, packets or messages for transmission, decode received frames or messages for further processing, and other tasks or functions described herein. Processor 1304, which may be a baseband processor, for example, may generate messages, packets, frames or other signals for transmission via wireless transceiver 1302 (1302A or 1302B). Processor 1304 may control transmission of signals or messages over a wireless network, and may control the reception of signals or messages, etc., via a wireless network (e.g., after being down- converted by wireless transceiver 1302, for example). Processor 1304 may be programmable and capable of executing software or other instructions stored in memory or on other computer media to perform the various tasks and functions described above, such as one or more of the tasks or methods described above. Processor 1304 may be (or may include), for example, hardware, programmable logic, a programmable processor that executes software or firmware, and / or any combination of these. Using other terminology, processor 1304 and transceiver 1302 together may be considered as a wireless transmitter / receiver system, for example.

[0155] In addition, referring to FIG. 7, a controller (or processor) 1308 may execute software and instructions, and may provide overall control for the station 1300, and may provide control for other systems not shown in FIG. 7, such as controlling input / output devices (e.g., display, keypad), and / or may execute software for one or more applications that may be provided on wireless station 1300, such as, for example, an email program, audio / video applications, a word processor, a Voice over IP application, or other application or software.

[0156] In addition, a storage medium may be provided that includes stored instructions, which when executed by a controller or processor may result in the processor 1304, or other controller or processor, performing one or more of the functions or tasks described above.

[0157] According to another example embodiment, RF or wireless transceiver(s) 1302A / 1302B may receive signals or data and / or transmit or send signals or data. Processor 1304 (and possibly transceivers 1302A / 1302B) may control the RF or wireless transceiver 1302 A or 1302B to receive, send, broadcast or transmit signals or data.

[0158] Example embodiments are provided or described for each of the example methods, including: An apparatus (e.g., 1300, FIG. 7) including means (e.g., processor 1304, RF transceivers 1302A and / or 1302B, and / or memory 1306, in FIG. 7) for carrying out any of the methods; a non-transitory computer-readable storage medium (e.g., memory 1306, FIG. 7) comprising instructions stored thereon that, when executed by at least one processor (processor 1304, FIG. 7), are configured to cause a computing system (e.g., 1300, FIG. 7) to perform any of the example methods; and an apparatus (e.g., 1300, FIG. 7) including at least one processor (e.g., processor 1304, FIG. 7), and at least one memory (e.g., memory 1306, FIG. 7) including computer program code, the at least one memory (1306) and the computer program code configured to, with the at least one processor (1304), cause the apparatus (e.g., 1300) at least to perform any of the example methods.

[0159] Embodiments of the various techniques described herein may be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. Embodiments may be implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, e.g., in a machine- readable storage device or in a propagated signal, for execution by, or to control the operation of, a data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. Embodiments may also be provided on a computer readable mediumor computer readable storage medium, which may be a non-transitory medium. Embodiments of the various techniques may also include embodiments provided via transitory signals or media, and / or programs and / or software embodiments that are downloadable via the Internet or other network(s), either wired networks and / or wireless networks. In addition, embodiments may be provided via machine type communications (MTC), and also via an Internet of Things (IOT).

[0160] As used in this application, the term ‘circuitry’ or “circuit” refers to all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and / or digital circuitry, and (b) combinations of circuits and soft-ware (and / or firmware), such as (as applicable): (i) a combination of processor(s) or (ii) portions of processor(s) / software including digital signal processor(s), software, and memory(ies) that work together to cause an apparatus to perform various functions, and (c) circuits, such as a microprocessor s) or a portion of a microprocessor s), that require software or firmware for operation, even if the software or firmware is not physically present. This definition of ‘circuitry’ applies to all uses of this term in this application. As a further example, as used in this application, the term ‘circuitry’ would also cover an implementation of merely a processor (or multiple processors) or a portion of a processor and its (or their) accompanying software and / or firmware. The term ‘circuitry’ would also cover, for example and if applicable to the particular element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or another network device.

[0161] The computer program may be in source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, distribution medium, or computer readable medium, which may be any entity or device capable of carrying the program. Such carriers include a record medium, computer memory, read-only memory, photoelectrical and / or electrical carrier signal, telecommunications signal, and software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer, or it may be distributed amongst a number of computers.

[0162] Furthermore, embodiments of the various techniques described herein may use a cyber-physical system (CPS) (a system of collaborating computational elements controlling physical entities). CPS may enable the embodiment and exploitation of massive amounts of interconnected ICT devices (sensors, actuators, processors microcontrollers, ...)embedded in physical objects at different locations. Mobile cyber physical systems, in which the physical system in question has inherent mobility, are a subcategory of cyberphysical systems. Examples of mobile physical systems include mobile robotics and electronics transported by humans or animals. The rise in popularity of smartphones has increased interest in the area of mobile cyber-physical systems. Therefore, various embodiments of techniques described herein may be provided via one or more of these technologies.

[0163] A computer program, such as the computer program(s) described above, can be written in any form of programming language, including compiled or interpreted languages, and can be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit or part of it suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.

[0164] Method steps may be performed by one or more programmable processors executing a computer program or computer program portions to perform functions by operating on input data and generating output. Method steps also may be performed by, and an apparatus may be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0165] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer, chip or chipset. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. Elements of a computer may include at least one processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer also may include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magnetooptical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory may be supplemented by, or incorporated in, special purpose logic circuitry.

[0166] To provide for interaction with a user, embodiments may be implemented on a computer having a display device, e.g., a cathode ray tube (CRT) or liquid crystal display (LCD) monitor, for displaying information to the user and a user interface, such as a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0167] Embodiments may be implemented in a computing system that includes a backend component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a frontend component, e.g., a client computer having a graphical user interface or a Web browser through which a user can interact with an embodiment, or any combination of such backend, middleware, or frontend components. Components may be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (LAN) and a wide area network (WAN), e.g., the Internet.

[0168] While certain features of the described embodiments have been illustrated as described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the various embodiments.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, by the apparatus, capable of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in one or more time units, from a network node, a configuration of reference signal resources; receive, reference signals via the configured reference signal resources; and acquire, based on measurements on the reference signals, downlink channel state information (CSI) associated with antenna ports of the configured reference signal resources over the one or more time units, while maintaining at least one of the receiver phase coherence or the amplitude coherence over the one or more time units.

2. The apparatus of claim 1, further comprising transmitting, by the apparatus to the network node, a capability indication that indicates the apparatus is capable of maintaining at least one of the receiver phase coherence or the amplitude coherence of the one or more received signals in the one or more time units.

3. The apparatus of claim 1, wherein the one or more time units comprises at least one of: one or more symbols; or one or more time slots.

4. The apparatus of claim 1, wherein the apparatus is further caused to transmit a CSI report based on the acquired CSI.

5. The apparatus of claim 2, wherein the capability indication comprises at least one of: a time value indicating a duration for which a receiver of the apparatus can maintain phase coherence;a time value indicating a duration for which the receiver of the apparatus can maintain amplitude coherence; a reference signal type; a maximum amplitude deviation for which the receiver of the apparatus can maintain the amplitude coherence; a number of receiving antenna port groups; or a phase rotation value or a maximum phase deviation for which the receiver of the apparatus can maintain the phase coherence.

6. The apparatus of claim 5, wherein the phase rotation value or the maximum phase deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a phase rotation value.

7. The apparatus of claim 5, wherein a value of the maximum amplitude deviation is indicated by a vector of bits, wherein each bit of the vector is associated with a maximum amplitude deviation value.

8. The apparatus of claim 2, wherein the capability indication comprises one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information is associated with a reference signal type.

9. The apparatus of claim 8, wherein the reference signal type comprises at least one of a non-zero power channel state information reference signal (NZP-CSI-RS), a phase tracking reference signal (PTRS), or a demodulation reference signal (DMRS).

10. The apparatus of claim 2, wherein the capability indication comprises one or more receiver phase coherence or amplitude coherence capability information, wherein each of the one or more receiver phase coherence or amplitude coherence capability information is associated with a set of receiver antenna port groups wherein the set of receiver antenna port groups comprise a plurality of logical receiving antenna ports associated with a plurality of physical antennas.

11. The apparatus of claim 2, wherein the capability indication comprises at least one of: a number of time domain symbols of the one or more received signals for which the receiver phase coherence or amplitude coherence can be maintained; or a number of reference signal receptions for which the receiver phase coherence or amplitude coherence can be maintained.

12. The apparatus of claim 2, wherein the received reference signals from the network node are coherent in phase or amplitude within a tolerance range based on the capability indication transmitted by the apparatus.

13. The apparatus of claim 2, wherein a downlink transmission from the network node associated with at least one of the reference signal resources, data channel resources, or control channel resources is coherent in phase or amplitude within a tolerance range based on the capability indication transmitted by the apparatus.

14. The apparatus of claim 13, wherein the reference signal resources comprise at least one of a non-zero power channel state information received signal (NZP-CSI-RS) resource, a phase tracking reference signal (PTRS) resource, or a demodulation reference signal (DMRS) resource.

15. A method comprising: receiving, by a user device, capable of maintaining at least one of receiver phase coherence or amplitude coherence of one or more received signals in one or more time units, from a network node, a configuration of reference signal resources; receiving reference signals via the configured reference signal resources; and acquiring, based on measurements on the reference signals, downlink channel state information (CSI) associated with antenna ports of the configured reference signal resources over the one or more time units, while maintaining at least one of the receiver phase coherence or the amplitude coherence over the one or more time units.

Images