Patent Description:
The Internet of Everything (IoE), which is a combination of the loT technology and the Big Data processing technology through connect ion with a cloud server, has emerged. As technology elements, such as "sensing technology" , "wired/wireless communication and network infrastructure" , "service interface technology" , and "Security technology" have been demanded for IoT implementation, a sensor network, a Machine-to-Machine (M2M) communication, Machine Type Communication (MTC), and so forth have been recently researched. Such an loT environment may provide intelligent Internet technology services that create a new value to human life by collecting and analyzing data generated among connected things. IoT may be appl ied to a variety of fields including smart home, smart building, smart city, smart car or connected cars, smart grid, health care, smart appliances and advanced medical services through convergence and combinat ion between existing Information Technology (IT) and various industrial applications.

In line with this, various attempts have been made to apply <NUM> communication systems to loT networks.

Understanding and correctly estimating the channel between a user equipment (UE) and a base station (BS) (e.g., gNode B (gNB)) is important for efficient and effective wireless communication. In order to correctly estimate the DL channel conditions, the gNB may transmit a reference signal, e.g., CSI-RS, to the UE for DL channel measurement, and the UE may report (e.g., feedback) information about channel measurement, e.g., CSI, to the gNB. With this DL channel measurement, the gNB is able to select appropriate communication parameters to efficiently and effectively perform wireless data communication with the UE.

The publication "<NPL>) represents a change request for TS <NUM>. The publication "<NPL>) shows the details and the procedures of the UE power schemes with cross-slot scheduling. <CIT> and <CIT> disclose a method for measuring and reporting channel state information in a wireless communication system. <CIT> and <CIT> disclose a WTRU that monitors CORSETs to receive a PDCCH having DCI that includes a scheduling offset and an indicated beam for a PDSCH reception. <CIT> discloses a method for beam management in unlicensed spectrum in a wireless communication system. The publication "<NPL>) summarizes ZTE's views on maintenance of Rel-<NUM> NR CSI measurement.

There are needs to enhance aperiodic reference signal transmission and reception procedures for accurate channel estimation.

Embodiments of the present disclosure provide methods and apparatuses to enable aperiodic reference signal reception/transmission in a wireless communication system.

In one embodiment, a terminal is provided as defined in the appended claims.

In another embodiment, a base station is provided as defined in the appended claims.

In yet another embodiment, a method performed by a terminal is provided as defined in the appended claims.

In another embodiment, a method performed by a base station is provided as defined in the appended claims.

According to various embodiments of the disclosure, channel estimation procedure can be enhanced accurately and efficiently.

The following documents and standards descriptions are relevant for the present disclosure: <NPL>;" <NPL>;" <NPL>;" <NPL>;" <NPL>;" 3GPP TR <NUM> v14. <NUM>; <NPL>;" <NPL>;" <NPL>;" and <NPL>.

Aspects, features, and advantages of the disclosure are readily apparent from the following detailed description, simply by illustrating a number of particular embodiments and implementations, including the best mode contemplated for carrying out the disclosure. Several details can be modified in various obvious respects, all without departing from the scope of the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. The disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. The scope is solely defined by the appended claims.

In the following, for brevity, both FDD and TDD are considered as the duplex method for both DL and UL signaling.

Although exemplary descriptions and embodiments to follow assume orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA), the present disclosure can be extended to other OFDM-based transmission waveforms or multiple access schemes such as filtered OFDM (F-OFDM).

Therefore, the <NUM> or pre-<NUM> communication system is also called a "beyond <NUM> network" or a "post LTE system.

To decrease propagation loss of the radio waves and increase the transmission coverage, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques and the like are discussed in <NUM> communication systems.

In addition, in <NUM> communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul communication, moving network, cooperative communication, coordinated multi-points (CoMP) transmission and reception, interference mitigation and cancellation and the like.

In the <NUM> system, hybrid frequency shift keying and quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) as an adaptive modulation and coding (AMC) technique, and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.

<FIG> below describe various embodiments implemented in wireless communications systems and with the use of orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) communication techniques. The descriptions of <FIG> are not meant to imply physical or architectural limitations to the manner in which different embodiments may be implemented. Different embodiments of the present disclosure may be implemented in any suitably-arranged communications system. The present disclosure covers several components which can be used in conjunction or in combination with one another, or can operate as standalone schemes.

<FIG> illustrates an example wi reless network according to embodiments of the present disclosure.

As shown in <FIG>, the wireless network includes a gNB <NUM>, a gNB <NUM>, and a gNB <NUM>. The gNB <NUM> communicates with the gNB <NUM> and the gNB <NUM>. The gNB <NUM> also communicates with at least one network <NUM>, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network.

The gNB <NUM> provides wireless broadband access to the network <NUM> for a first plurality of user equipments (UEs) within a coverage area <NUM> of the gNB <NUM>. The first plural ity of UEs includes a UE <NUM>, which may be located in a small business (SB); a UE <NUM>, which may be located in an enterprise (E); a UE <NUM>, which may be located in a WiFi hotspot (HS); a UE <NUM>, which may be located in a first residence (R); a UE <NUM>, which may be located in a second residence (R); and a UE <NUM>, which may be a mobile device (M), such as a cell phone, a wireless laptop, a wireless PDA, or the like. The gNB <NUM> provides wireless broadband access to the network <NUM> for a second plurality of UEs within a coverage area <NUM> of the gNB <NUM>. The second plurality of UEs includes the UE <NUM> and the UE <NUM>. In some embodiments, one or more of the gNBs <NUM>-<NUM> may communicate with each other and with the UEs <NUM>-<NUM> using <NUM>, LTE, LTE-A, WiMAX, WiFi, or other wireless communication techniques.

Depending on the network type, the term "base station" or "BS" can refer to any component (or collection of components) configured to provide wireless access to a network, such as transmit point (TP), transmit-receive point (TRP), an enhanced base station (eNodeB or eNB), a <NUM> base station (gNB), a macrocell, a femtocell, a WiFi access point (AP), or other wirelessly enabled devices. Base stations may provide wireless access in accordance with one or more wireless communication protocols, e.g., <NUM> 3GPP new radio interface/access (NR), long term evolution (LTE), LTE advanced (LTE-A), high speed packet access (HSPA), Wi-Fi <NUM>. 11a/b/g/n/ac, etc. For the sake of convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. Also, depending on the network type, the term "user equipment" or "UE" can refer to any component such as "mobile station," "subscriber station," "remote terminal," "wireless terminal," "receive point," or "user device. " For the sake of convenience, the terms "user equipment" and "UE" are used in this patent document to refer to remote wireless equipment that wirelessly accesses a BS, whether the UE is a mobile device (such as a mobile telephone or smartphone) or is normally considered a stationary device (such as a desktop computer or vending machine).

As described in more detail below, one or more of the UEs <NUM>-<NUM> include circuitry, programing, or a combination thereof, for receiving aperiodic CSI-RS to determine and report CSI for communications in a wireless communication system. In certain embodiments, and one or more of the gNBs <NUM>-<NUM> includes circuitry, programing, or a combination thereof, for transmitting aperiodic CSI-RS to acquire CSI in a wireless communication system.

The control ler/processor <NUM> can include one or more processors or other processing devices that control the overall operation of the gNB <NUM>. For example, the controller/processor <NUM> could control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceivers 210a-210n, the RX processing circuitry <NUM>, and the TX processing circuitry <NUM> in accordance with well-known principles. The controller/processor <NUM> could support additional functions as well, such as more advanced wireless communication functions.

For instance, the controller/processor <NUM> could support beam forming or directional routing operations in which outgoing signals from multiple antennas 205a-205n are weighted differently to effectively steer the outgoing signals in a desired direction. Any of a wide variety of other functions could be supported in the gNB <NUM> by the controller/processor <NUM>.

The processor <NUM> is also capable of executing other processes and programs resident in the memory <NUM>, such as processes for CSI-RS measurement and for CSI feedback on uplink channel. The processor <NUM> can move data into or out of the memory <NUM> as required by an executing process. In some embodiments, the processor <NUM> is configured to execute the applications <NUM> based on the OS <NUM> or in response to signals received from gNBs or an operator. The processor <NUM> is also coupled to the I/O interface <NUM>, which provides the UE <NUM> with the ability to connect to other devices, such as laptop computers and handheld computers. The I/O interface <NUM> is the communication path between these accessories and the processor <NUM>.

<FIG> is a high-level diagram of transmit path circuitry. For example, the transmit path circuitry may be used for an orthogonal frequency division multiple access (OFDMA) communication. <FIG> is a high-level diagram of receive path circuitry. For example, the receive path circuitry may be used for an orthogonal frequency division multiple access (OFDMA) communication. In <FIG> and <FIG>, for downlink communication, the transmit path circuitry may be implemented in a base station (gNB) <NUM> or a relay station, and the receive path circuitry may be implemented in a user equipment (e.g., user equipment <NUM> of <FIG>). In other examples, for uplink communication, the receive path circuitry <NUM> may be implemented in a base station (e.g., gNB <NUM> of <FIG>) or a relay station, and the transmit path circuitry may be implemented in a user equipment (e.g., user equipment <NUM> of <FIG>).

Transmit path circuitry comprises channel coding and modulation block <NUM>, serial-to-parallel (S-to-P) block <NUM>, Size N Inverse Fast Fourier Transform (IFFT) block <NUM>, parallel-to-serial (P-to-S) block <NUM>, add cyclic prefix block <NUM>, and up-converter (UC) <NUM>. Receive path circuitry <NUM> comprises down-converter (DC) <NUM>, remove cyclic prefix block <NUM>, serial-to-parallel (S-to-P) block <NUM>, Size N Fast Fourier Transform (FFT) block <NUM>, parallel-to-serial (P-to-S) block <NUM>, and channel decoding and demodulation block <NUM>.

At least some of the components in <FIG> <NUM> and <FIG> <NUM> may be implemented in software, while other components may be implemented by configurable hardware or a mixture of software and configurable hardware. In particular, it is noted that the FFT blocks and the IFFT blocks described in this disclosure document may be implemented as configurable software algorithms, where the value of Size N may be modified according to the implementation.

Furthermore, although this disclosure is directed to an embodiment that implements the Fast Fourier Transform and the Inverse Fast Fourier Transform, this is by way of illustration only and may not be construed to limit the scope of the disclosure. It may be appreciated that in an alternate embodiment of the present disclosure, the Fast Fourier Transform functions and the Inverse Fast Fourier Transform functions may easily be replaced by discrete Fourier transform (DFT) functions and inverse discrete Fourier transform (IDFT) functions, respectively. It may be appreciated that for DFT and IDFT functions, the value of the N variable may be any integer number (i.e., <NUM>, <NUM>, <NUM>, <NUM>, etc.), while for FFT and IFFT functions, the value of the N variable may be any integer number that is a power of two (i.e., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, etc.).

In transmit path circuitry <NUM>, channel coding and modulation block <NUM> receives a set of information bits, applies coding (e.g., LDPC coding) and modulates (e.g. , quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) the input bits to produce a sequence of frequency-domain modulation symbols. Serial-to-parallel block <NUM> converts (i.e., de-multiplexes) the serial modulated symbols to parallel data to produce N parallel symbol streams where N is the IFFT/FFT size used in BS <NUM> and UE <NUM>. Size N IFFT block <NUM> then performs an IFFT operation on the N parallel symbol streams to produce time-domain output signals. Parallel-to-serial block <NUM> converts (i.e., multiplexes) the parallel time-domain output symbols from Size N IFFT block <NUM> to produce a serial time-domain signal. Add cyclic prefix block <NUM> then inserts a cyclic prefix to the time-domain signal. Finally, up-converter <NUM> modulates (i.e., up-converts) the output of add cyclic prefix block <NUM> to RF frequency for transmission via a wireless channel. The signal may also be filtered at baseband before conversion to RF frequency.

The transmitted RF signal arrives at the UE <NUM> after passing through the wireless channel, and reverse operations to those at gNB <NUM> are performed. Down-converter <NUM> down-converts the received signal to baseband frequency, and remove cyclic prefix block <NUM> removes the cyclic prefix to produce the serial time-domain baseband signal. Serial-to-parallel block <NUM> converts the time-domain baseband signal to parallel time-domain signals. Size N FFT block <NUM> then performs an FFT algorithm to produce N parallel frequency-domain signals. Parallel-to-serial block <NUM> converts the parallel frequency-domain signals to a sequence of modulated data symbols. Channel decoding and demodulation block <NUM> demodulates and then decodes the modulated symbols to recover the original input data stream.

Each of gNBs <NUM>-<NUM> may implement a transmit path that is analogous to transmitting in the downlink to user equipment <NUM>-<NUM> and may implement a receive path that is analogous to receiving in the uplink from user equipment <NUM>-<NUM>. Similarly, each one of user equipment <NUM>-<NUM> may implement a transmit path corresponding to the architecture for transmitting in the uplink to gNBs <NUM>-<NUM> and may implement a receive path corresponding to the architecture for receiving in the downlink from gNBs <NUM>-<NUM>.

The <NUM> communication system use cases have been identified and described. Those use cases can be roughly categorized into three different groups. In one example, enhanced mobile broadband (eMBB) is determined to do with high bits/sec requirement, with less stringent latency and reliability requirements. In another example, ultra reliable and low latency (URLL) is determined with less stringent bits/sec requirement. In yet another example, massive machine type communication (mMTC) is determined that a number of devices can be as many as <NUM>,<NUM> to <NUM> million per km2, but the reliability/throughput/latency requirement could be less stringent. This scenario may also involve power efficiency requirement as well, in that the battery consumption may be minimized as possible.

A communication system includes a downlink (DL) that conveys signals from transmission points such as base stations (BSs) or NodeBs to user equipments (UEs) and an Uplink (UL) that conveys signals from UEs to reception points such as NodeBs. A UE, also commonly referred to as a terminal or a mobile station, may be fixed or mobile and may be a cellular phone, a personal computer device, or an automated device. An eNodeB, which is generally a fixed station, may also be referred to as an access point or other equivalent terminology. For LTE systems, a NodeB is often referred as an eNodeB.

In a communication system, such as LTE system, DL signals can include data signals conveying information content, control signals conveying DL control information (DCI), and reference signals (RS) that are also known as pilot signals. An eNodeB transmits data information through a physical DL shared channel (PDSCH). An eNodeB transmits DCI through a physical DL control channel (PDCCH) or an Enhanced PDCCH (EPDCCH).

An eNodeB transmits acknowledgement information in response to data transport block (TB) transmission from a UE in a physical hybrid ARQ indicator channel (PHICH). An eNodeB transmits one or more of multiple types of RS including a UE-common RS (CRS), a channel state information RS (CSI-RS), or a demodulation RS (DMRS). A CRS is transmitted over a DL system bandwidth (BW) and can be used by UEs to obtain a channel estimate to demodulate data or control information or to perform measurements. To reduce CRS overhead, an eNodeB may transmit a CSI-RS with a smaller density in the time and/or frequency domain than a CRS. DMRS can be transmitted only in the BW of a respective PDSCH or EPDCCH and a UE can use the DMRS to demodulate data or control information in a PDSCH or an EPDCCH, respectively. A transmission time interval for DL channels is referred to as a subframe and can have, for example, duration of <NUM> millisecond.

DL signals also include transmission of a logical channel that carries system control information. A BCCH is mapped to either a transport channel referred to as a broadcast channel (BCH) when the DL signals convey a master information block (MIB) or to a DL shared channel (DL-SCH) when the DL signals convey a System Information Block (SIB). Most system information is included in different SIBs that are transmitted using DL-SCH. A presence of system information on a DL-SCH in a subframe can be indicated by a transmission of a corresponding PDCCH conveying a codeword with a cyclic redundancy check (CRC) scrambled with system information RNTI (SI-RNTI). Alternatively, scheduling information for a SIB transmission can be provided in an earlier SIB and scheduling information for the first SIB (SIB-<NUM>) can be provided by the MIB.

DL resource allocation is performed in a unit of subframe and a group of physical resource blocks (PRBs). A transmission BW includes frequency resource units referred to as resource blocks (RBs). Each RB includes <MAT> sub-carriers, or resource elements (REs), such as <NUM> REs. A unit of one RB over one subframe is referred to as a PRB. A UE can be allocated MPDSCH RBs for a total of <MAT> REs for the PDSCH transmission BW.

UL signals can include data signals conveying data information, control signals conveying UL control information (UCI), and UL RS. UL RS includes DMRS and Sounding RS (SRS). A UE transmits DMRS only in a BW of a respective PUSCH or PUCCH. An eNodeB can use a DMRS to demodulate data signals or DCI signals. A UE transmits SRS to provide an eNodeB with an UL CSI. A UE transmits data information or UCI through a respective physical UL shared channel (PUSCH) or a Physical UL control channel (PUCCH). If a UE needs to transmit data information and UCI in a same UL subframe, the UE may multiplex both in a PUSCH. UCI includes Hybrid Automatic Repeat request acknowledgement (HARQ-ACK) information, indicat ing correct (ACK) or incorrect (NACK) detection for a data TB in a PDSCH or absence of a PDCCH detection (DTX), scheduling request (SR) indicating whether a UE has data in the UE' s buffer, rank indicator (RI), and channel state information (CSI) enabling an eNodeB to perform link adaptation for PDSCH transmissions to a UE. HARQ-ACK information is also transmitted by a UE in response to a detection of a PDCCH/EPDCCH indicating a release of semi-persistently scheduled PDSCH.

An UL subframe includes two slots. Each slot includes <MAT> symbols for transmitting data information, UCI, DMRS, or SRS. A frequency resource unit of an UL system BW is a RB. A UE is allocated NRB RBs for a total of <MAT> REs for a transmission BW. For a PUCCH, NRB=<NUM>. A last subframe symbol can be used to multiplex SRS transmissions from one or more UEs. A number of subframe symbols that are available for data/UCI/DMRS transmission is <MAT>, where NSRS=<NUM> if a last subframe symbol is used to transmit SRS and NSRS = <NUM> otherwise.

<FIG> illustrates a transmitter block diagram <NUM> for a PDSCH in a subframe according to embodiments of the present disclosure. The embodiment of the transmitter block diagram <NUM> illustrated in <FIG> is for illustration only. One or more of the components illustrated in <FIG> can be implemented in specialized circuitry configured to perform the noted functions or one or more of the components can be implemented by one or more processors executing instructions to perform the noted functions. <FIG> does not limit the scope of this disclosure to any particular implementation of the transmitter block diagram <NUM>.

As shown in <FIG>, information bits <NUM> are encoded by encoder <NUM>, such as a turbo encoder, and modulated by modulator <NUM>, for example using quadrature phase shift keying (QPSK) modulation. A serial to parallel (S/P) converter <NUM> generates M modulation symbols that are subsequently provided to a mapper <NUM> to be mapped to REs selected by a transmission BW selection unit <NUM> for an assigned PDSCH transmission BW, unit <NUM> appl ies an Inverse fast Fourier transform (IFFT), the output is then serialized by a parallel to serial (P/S) converter <NUM> to create a time domain signal, filtering is applied by filter <NUM>, and a signal transmitted <NUM>. Additional functionalities, such as data scrambling, cyclic prefix insertion, time windowing, interleaving, and others are well known in the art and are not shown for brevity.

<FIG> illustrates a receiver block diagram <NUM> for a PDSCH in a subframe according to embodiments of the present disclosure. The embodiment of the diagram <NUM> illustrated in <FIG> is for illustration only. One or more of the components illustrated in <FIG> can be implemented in specialized circuitry configured to perform the noted functions or one or more of the components can be implemented by one or more processors executing instructions to perform the noted functions. <FIG> does not limit the scope of this disclosure to any particular implementation of the diagram <NUM>.

As shown in <FIG>, a received signal <NUM> is filtered by filter <NUM>, REs <NUM> for an assigned receptionBW are selected by BW selector <NUM>, unit <NUM> applies a fast Fourier transform (FFT), and an output is serialized by a parallel-to-serial converter <NUM>. Subsequently, a demodulator <NUM> coherently demodulates data symbols by applying a channel estimate obtained from a DMRS or a CRS (not shown), and a decoder <NUM>, such as a turbo decoder, decodes the demodulated data to provide an estimate of the information data bits <NUM>. Additional functionalities such as time-windowing, cyclic prefix removal, de-scrambling, channel estimation, and de-interleaving are not shown for brevity.

<FIG> illustrates a transmitter block diagram <NUM> for a PUSCH in a subframe according to embodiments of the present disclosure. The embodiment of the block diagram <NUM> illustrated in <FIG> is for illustration only. One or more of the components illustrated in <FIG> can be implemented in specialized circuitry configured to perform the noted functions or one or more of the components can be implemented by one or more processors executing instructions to perform the noted functions. <FIG> does not limit the scope of this disclosure to any particular implementation of the block diagram <NUM>.

As shown in <FIG>, information data bits <NUM> are encoded by encoder <NUM>, such as a turbo encoder, and modulated by modulator <NUM>. A discrete Fourier transform (DFT) unit <NUM> applies a DFT on the modulated data bits, REs <NUM> corresponding to an assigned PUSCH transmission BW are selected by transmission BW selection unit <NUM>, unit <NUM> applies an IFFT and, after a cyclic prefix insertion (not shown), filtering is applied by filter <NUM> and a signal transmitted <NUM>.

<FIG> illustrates a receiver block diagram <NUM> for a PUSCH in a subframe according to embodiments of the present disclosure. The embodiment of the block diagram <NUM> illustrated in <FIG> is for illustration only. One or more of the components illustrated in <FIG> can be implemented in specialized circuitry configured to perform the noted functions or one or more of the components can be implemented by one or more processors executing instructions to perform the noted functions. <FIG> does not limit the scope of this disclosure to any particular implementation of the block diagram <NUM>.

As shown in <FIG>, a received signal <NUM> is filtered by filter <NUM>. Subsequently, after a cyclic prefix is removed (not shown), unit <NUM> applies a FFT, REs <NUM> corresponding to an assigned PUSCH reception BW are selected by a reception BW selector <NUM>, unit <NUM> applies an inverse DFT (IDFT), a demodulator <NUM> coherently demodulates data symbols by applying a channel estimate obtained from a DMRS (not shown), a decoder <NUM>, such as a turbo decoder, decodes the demodulated data to provide an estimate of the information data bits <NUM>.

<FIG> illustrates an example antenna blocks <NUM> according to embodiments of the present disclosure. The embodiment of the antenna blocks <NUM> illustrated in <FIG> is for illustration only. <FIG> does not limit the scope of this disclosure to any particular implementation of the antenna blocks <NUM>.

The 3GPP LTE and NR specifications support up to <NUM> CSI-RS antenna ports which enable an eNB to be equipped with a large number of antenna elements (such as <NUM> or <NUM>). In this case, a plurality of antenna elements is mapped onto one CSI-RS port. For next generation cellular systems such as <NUM>, the maximum number of CSI-RS ports can either remain the same or increase. For mmWave bands, although the number of antenna elements can be larger for a given form factor, the number of CSI-RS ports -which can correspond to the number of digitally precoded ports - tends to be limited due to hardware constraints (such as the feasibility to install a large number of ADCs/DACs at mmWave frequencies) as illustrated in <FIG>. In this case, one CSI-RS port is mapped onto a large number of antenna elements which can be controlled by a bank of analog phase shifters <NUM>. One CSI-RS port can then correspond to one sub-array which produces a narrow analog beam through analog beamforming <NUM>. This analog beam can be configured to sweep across a wider range of angles <NUM> by varying the phase shifter bank across symbols or subframes. The number of sub-arrays (equal to the number of RF chains) is the same as the number of CSI-RS ports NCSI-PORT. A digital beamforming unit <NUM> performs a linear combination across NCSI-PORT analog beams to further increase precoding gain. While analog beams are wideband (hence not frequency-selective), digital precoding can be varied across frequency sub-bands or resource blocks. Receiver operation can be conceived analogously.

The UL SU-MIMO transmission is supported using a codebook-based transmission scheme. In LTE UL codebook, pre-coders with antenna selection has been supported in order to keep peak-to-average power ratio (PAPR) low and cubic-metric (CM) for rank > <NUM> small. Antenna selection offers performance improvement in some scenarios, especially for SC-FDMA based UL in LTE.

In <NUM> NR systems, two UL transmission schemes are supported, namely codebook-based and non-codebook-based. The codebook-based transmission scheme is based on an UL codebook similar to LTE. The NR UL codebook, however, is dependent on whether or not the UE is capable to transmit UL data (PUSCH) using all of, or a subset of antenna ports. For example, the UE can be capable of at least one of full-coherent (all antenna ports), partial-coherent (a subset of antenna ports), or non-coherent UL transmission (a single antenna port) to transmit a layer in UL. The <NUM> NR UL codebook has been designed keeping this UE coherence capability in mind.

In both LTE and NR, an UL grant (containing DCI format <NUM> for LTE and DCI format 0_1 for NR) includes a single TPMI field (along with TRI) which indicates the single precoding vector or matrix (from the UL codebook) a UE shall use for the scheduled UL transmission. Therefore, when multiple PRBs are allocated to the UE, a single precoding matrix indicated by the PMI implies that wideband UL precoding is utilized. Despite its simplicity, this is clearly sub-optimal since typical UL channel is frequency-selective and a UE is frequency scheduled to transmit using multiple PRBs. Yet another drawback of UL SU-MIMO is the lack of support for scenarios where accurate UL-CSI is unavailable at the eNB or gNB (which is important for properly operating codebook-based transmission). This situation can happen in scenarios with high-mobility UEs or bursty inter-cell interference in cells with poor isolation. Therefore, there is a need for designing new components to enable more efficient support for UL MIMO for the following reasons. First, the support for frequency-selective (or subband) precoding for UL MIMO is desired whenever possible. Second, UL MIMO should offer competitive performance even when accurate UL-CSI is unavailable at the eNB. Third, the proposed UL MIMO solution should be able to exploit UL-DL reciprocity where CSI-RS is utilized by the UE to provide UL-CSI estimation for TDD and FDD (with partial UL-DL reciprocity) scenarios. As described in <CIT> and entitled "Method and Apparatus for Enabling Uplink MIM,", such efficient UL MIMO operations and components have been proposed. Similar to LTE, MIMO has been identified as an essential feature for <NUM> NR in order to achieve high system throughput requirements. One of the key components of a MIMO transmission scheme is the accurate CSI acquisition at the eNB (or TRP). For MU-MIMO, in particular, the availability of accurate CSI is necessary in order to guarantee high MU performance. For TDD systems, the CSI can be acquired using the SRS transmission (from a UE) relying on the channel reciprocity. For FDD systems, on the other hand, it can be acquired using the CSI-RS transmission from eNB, and CSI-RS measurement and CSI feedback from UE. In NR, two CSI reporting mechanisms are supported, Type I for low resolution CSI reporting and Type II for high resolution CSI reporting. In this disclosure, the term "measurement RS" is used to denote SRS or CSI-RS used for CSI measurement/reporting. The measurement RS (SRS or CSI-RS) can be dynamically triggered by the NW/gNB (e.g., via DCI in case of aperiodic RS), preconfigured with a certain time-domain behavior (such as periodicity and offset, in case of periodic RS), or a combination of such pre-configuration and activation/deactivation (in case of semi-persistent RS). <FIG> illustrates an aperiodic CSI-RS measurement and aperiodic CSI reporting operation <NUM> according to embodiments of the present disclosure. The embodiment of the aperiodic CSI-RS measurement and aperiodic CSI reporting operation <NUM> illustrated in <FIG> is for illustration only. <FIG> does not limit the scope of this disclosure to any particular implementation of the aperiodic CSI-RS measurement and aperiodic CSI reporting operation <NUM>.

When measurement RS is CSI-RS, an aperiodic CSI-RS transmission linked with an aperiodic CSI reporting is triggered via the CSI request field in DCI carried on PDCCH. In one example illustrated in <FIG>, an aperiodic CSI-RS measurement and aperiodic CSI reporting operation <NUM> starts with the gNB/NW signaling to a UE an aperiodic CSI-RS (AP-CSI-RS) trigger or indication (step <NUM>). This trigger or indication can be included in a DCI (either UL-related or DL-related, either separately or jointly signaled with an aperiodic CSI request/trigger) and indicate transmission of AP-CSI-RS in a same (zero time offset) or later slot/sub-frame (><NUM> time offset). Upon receiving the AP-CSI-RS transmitted by the gNB/NW (step <NUM>), the UE measures the AP-CSI-RS and, in turn, calculates and reports an aperiodic CSI (step <NUM>) comprising, for example, all or a subset of RI, CQI, PMI, LI, and CRI. Upon receiving the CSI report from the UE, the NW can use the CSI report for data (PDSCH) transmission (step <NUM>), and the UE can receive the data (PDSCH) transmission (step <NUM>).

Let µCSIRS and µPDCCH be the subcarrier spacing (SCS) configurations for CSI-RS and PDCCH, respectively. In one example, µCSIRS and µPDCCH take a value from {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>} which correspond to (or indicate) subcarrier spacing values {<NUM>, <NUM>, <NUM>, <NUM>}.

For subcarrier spacing configuration µ, slots are numbered <MAT> <MAT> in increasing order within a subframe and <MAT> in increasing order within a frame. There are <MAT> consecutive OFDM symbols in a slot where <MAT> depends on the cyclic prefix as given by Table <NUM> and Table <NUM>. The start of slot <MAT> in a subframe is aligned in time with the start of OFDM symbol <MAT> in the same subframe.

When µCSIRS = µPDCCH, the numerologies of PDCCH and CSI-RS are the same, hence the time offset for AP-CSI-RS transmission, as shown in <FIG>, is the same in two numerologies. When µCSIRS ≠ µPDCCH, however, the numerologies of PDCCH and CSI-RS are different, hence the time offset for AP-CSI-RS transmission, as shown in <FIG>, can only be in one of the two numerologies. It is unclear which of the two numerologies is used for the time offset, and what are the additional steps required to determine in this case of mixed numerologies. This disclosure proposes example embodiments to address these questions.

In one embodiment <NUM>, for each aperiodic CSI-RS resource in a CSI-RS resource set associated with each CSI triggering state, the UE is indicated the quasi co-location (QCL) configuration of quasi co-location RS source(s) and quasi co-location type(s), as described in NR, through higher layer signaling of qcl-info which contains a list of references to TCI-State's for the aperiodic CSI-RS resources associated with the CSI triggering state. If a State referred to in the list is configured with a reference to an RS associated with 'QCL-TypeD' , that RS may be an SS/PBCH block located in the same or different CC/DL BWP or a CSI-RS resource configured as periodic or semi-persistent located in the same or different CC/DL BWP. The UE applies the QCL assumption when receiving the aperiodic CSI-RS based on a condition on the scheduling offset (δ) between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resources in a NZP-CSI-RS-ResourceSet configured without higher layer parameter trs-Info and without the higher layer parameter repetition. At least one of the following sub-embodiments can be used. Note that the unit of the scheduling offset (δ) is OFDM symbol(s).

In sub-embodiment 1A, the UE does not expect that the SCS associated with the PDCCH carrying the triggering DCI is greater than the CSI-RS SCS, i.e., µPDCCH ≤ µCSI-RS, and the scheduling offset is defined in the numerology of the aperiodic CSI-RS, µCSI-RS.

When scheduling offset is smaller than a threshold α, i.e., δ < α,.

When schedul ing offset is equal to or greater than the threshold α, i.e. , δ ≥ α,
* the UE is expected to apply the QCL assumptions in the indicated TCI states for the aperiodic CSI-RS resources in the CSI triggering state indicated by the CSI trigger field in DCI.

The threshold α is determined according to at least one of the following examples.

In one example 1A-<NUM>, the threshold α = Y + d, where.

In one example 1A-<NUM>, the threshold α = Y×d, where.

In one example 1A-<NUM>, the threshold α = Y × d, where.

The parameter M in example 1A-<NUM> through 1A-<NUM> is determined according to at least one of the following alternatives (Alt).

In another example, the m value is given by the following:.

where <MAT> or <MAT> or <MAT>. In these examples, the m value can either be without the quantization step (cf. Ex 3A-6a-<NUM>) or with the quantization step (cf. Ex 3A-6a-<NUM>).

In one example 1A-<NUM>, the threshold α = Y(<NUM> + d), where.

In one example 1A-<NUM>, the threshold <MAT>, where.

In sub-embodiment 1B, there is no restriction on PDCCH and CSI-RS SCSs, i.e., µPDCCH and µCSI-RS can take any values, and the scheduling offset is defined in the numerology of the aperiodic CSI-RS µCSI-RS. The rest of the details are the same as or analogous to those in sub-embodiment 1A (including all examples and alternatives) except that the condition "if the PDCCH SCS is equal the CSI-RS SCS (µPDCCH = µCSI-RS)" in some of the above examples (example 1A-<NUM> through example 1A-<NUM>) is replaced with the condition "if the PDCCH SCS is larger than or equal the CSI-RS SCS (µDCCH ≥ µCSI-RS)".

In sub-embodiment 1C, there is no restriction on PDCCH and CSI-RS SCSs, i.e., µPDCCH and µCSI-RS can take any values. The schedul ing offset is defined based on the maximum subcarrier spacing between the PDCCH and the aperiodic CSI-RS. Hence, when µPDCCH ≤ µCSI-RS, the schedul ing offset is defined in the numerology of the aperiodic CSI-RS µCSI-RS and the rest of the details are the same as or analogous to those in sub-embodiment 1A (including all examples and alternatives). When µPDCCH > µCSI-RS, the scheduling offset is defined in the numerology of the PDCCH µPDCCH and the rest of the details are the same as in sub-embodiment 1A (including all examples and alternatives) except that µCSI-RS and µPDCCH are swapped everywhere, i.e., µCSI-RS is replaced with µPDCCH and µPDCCH is replaced with µCSI-RS.

In sub-embodiment 1D, there is no restriction on PDCCH and CSI-RS SCSs, i.e., µPDCCH and µCSI-RS can take any values. The scheduling offset is defined based on the minimum subcarrier spacing between the PDCCH and the aperiodic CSI-RS. Hence, when µPDCCH > µCSI-RS, the scheduling offset is defined in the numerology of the aperiodic CSI-RS µCSI-RS and the rest of the details are the same as or analogous to those in sub-embodiment 1A (including all examples and alternatives). When µPDCCH ≤ µCSI-RS, the scheduling offset is defined in the numerology of the PDCCH µPDCCH and the rest of the details are the same as or analogous to those in sub-embodiment 1A (including all examples and alternatives) except that µCSI-RS and µPDCCH are swapped everywhere, i.e., µCSI-RS is replaced with µPDCCH and µPDCCH is replaced with µCSI-RS.

In one embodiment <NUM>, when aperiodic CSI-RS is used with aperiodic CSI reporting, the CSI-RS triggering offset X is conf igured per resource set by the higher layer parameter aperiodicTriggeringOffset. The CSI-RS triggering offset has the values of {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>} slots. Note that the unit of the CSI-RS triggering offset is slot(s). The aperiodic CSI-RS is transmitted in slot n' +X, where X is the CSI-RS triggering offset in the numerology of CSI-RS according to the higher layer parameter aperiodicTriggeringOffset, and n' is the reference slot used to apply the slot offset for AP-CSI-RS transmission. If all the associated trigger states do not have the higher layer parameter qcl-Type set to 'QCL-TypeD' in the corresponding TCI states and the PDCCH SCS is equal to the CSI-RS SCS, the CSI-RS triggering offset X is fixed to zero.

The value n' depends on whether µPDCCH = µCSI-RS or µPDCCH ≠ µCSI-RS. At least one of the following sub-embodiments can be used.

In one sub-embodiment 2A, the UE does not expect that the SCS associated with the PDCCH carrying the triggering DCI is greater than the CSI-RS SCS, i.e., µPDCCH ≤ µCSI-RS, and the slot offset is defined in the numerology of the aperiodic CSI-RS, µCSI-RS. Let n be the slot with the triggering DCI in the numerology of the PDCCH containing the triggering DCI. The reference slot n' is then determined according to at least one of the following examples.

In one example 2A-<NUM>, <MAT> or n' = <MAT> or <MAT>.

In one example 2A-<NUM>, <MAT> or <MAT> or <MAT> <MAT>.

In one example 2A-<NUM>, <MAT> or <MAT> or <MAT> <MAT>, where e is an indicator which takes a value e = <NUM> when µPDCCH = µCSI-RS and another value e = <NUM> otherwise.

In one example 2A-<NUM>, <MAT>, where e is an indicator which takes a value e = <NUM> when µPDCCH = µCSI-RS and another value e = <NUM> otherwise.

In one sub-embodiment 2B, there is no restriction on PDCCH and CSI-RS SCSs, i.e., µPDCCH and µCSI-RS can take any values, and the slot offset is defined in the numerology of the aperiodic CSI-RS µCSI-RS. The rest of the details are the same as or analogous to those in sub-embodiment 2A (including all examples and alternatives) except that the condition "if the PDCCH SCS is equal the CSI-RS SCS (µPDCCH = µCSI-RS)" in some of the above examples (example 2A-<NUM> through example 2A-<NUM>) is replaced with the condition "if the PDCCH SCS is larger than or equal the CSI-RS SCS (µPDCCH ≥ µCSI-RS)".

In one sub-embodiment 2C, there is no restriction on PDCCH and CSI-RS SCSs, i.e., µPDCCH and µCSI-RS can take any values. The slot offset is defined based on the maximum subcarrier spacing between the PDCCH and the aperiodic CSI-RS. Hence, when µPDCCH < µCSI-RS, the slot offset is defined in the numerology of the aperiodic CSI-RS µCSI-RS and the rest of the details are the same as or analogous to those in sub-embodiment 2A (including all examples and alternatives). When µPDCCH > µCSI-RS, the slot offset is defined in the numerology of the PDCCH µPDCCH and the rest of the details are the same as or analogous to those in sub-embodiment 2A (including all examples and alternatives) except that µCSI-RS and µPDCCH are swapped everywhere, i.e., µCSI-RS is replaced with µPDCCH and µPDCCH is replaced with µCSI-RS.

In one sub-embodiment 2D, there is no restriction on PDCCH and CSI-RS SCSs, i.e., µPDCCH and µCSI-RS can take any values. The slot offset is defined based on the minimum subcarrier spacing between the PDCCH and the aperiodic CSI-RS. Hence, when µPDCCH > µCSI-RS, the slot offset is defined in the numerology of the aperiodic CSI-RS µCSI-RS and the rest of the details are the same as or analogous to those in sub-embodiment 2A (including all examples and alternatives). When µPDCCH ≤ µCSI-RS, the slot offset is defined in the numerology of the PDCCH µPDCCH and the rest of the details are the same as or analogous to those in sub-embodiment 2A (including all examples and alternatives) except that µCSI-RS and µPDCCH are swapped everywhere, i.e., µCSI-RS is replaced with µPDCCH and µPDCCH is replaced with µCSI-RS.

In one sub-embodiment 2E, the CSI-RS triggering offset X in some embodiments of this disclosure, takes a value from a set S, where the unit for X is slots in the numerology of the CSI-RS, and the set S includes {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>}. The set S also includes additional values in an another set T, where the another set T is according to at least one of the following alternatives.

In one sub-embodiment 2F, the set S includes additional values according to Alt 2E-<NUM> through Alt 2E-<NUM> of sub-embodiment 2E only when a certain condition is satisfied. For example, the certain condition can be based on the values for µPDCCH and µCSI-RS. At least one of the following alternatives can be used for the certain condition.

In one alternative Alt 2F-<NUM>, the set S includes additional values in the set T for both cases when µPDCCH > µCSI-RS and µPDCCH < µCSI-RS, where the set T is the same for both cases when nPDCCH > µCSI-RS and µPDCCH < µCSI-RS, and is according to at least one of Alt 2E-<NUM> through Alt 2E-<NUM>. When µPDCCH = µCSI-RS, the set S = {<NUM>,<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>}.

In one alternative Alt 2F-1a, the set S includes additional values in the set T for both cases when µPDCCH > µCSI-RS and µPDCCH < µCSI-RS, where the set T can be different for both cases when µPDCCH > µCSI-RS and µPDCCH < µCSI-RS, and is according to at least one of Alt 2E-<NUM> through Alt 2E-<NUM>. When µPDCCH = µCSI-RS, the set S = {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>}.

In one alternative Alt 2F-<NUM>, the set S includes additional values in the set T for both cases when µPDCCH > µCSI-RS and µPDCCH ≤ µCSI-RS, where the set T is the same for both cases when µPDCCH > µCSI-RS and µPDCCH ≤ µCSI-RS, and is according to at least one of Alt 2E-<NUM> through Alt 2E-<NUM>.

In one alternative Alt 2F-2a, the set S includes additional values in the set T for both cases when µPDCCH > µCSI-RS and µPDCCH ≤ µCSI-RS, where the set T can be different for both cases when µPDCCH > µCSI-RS and µPDCCH ≤ µCSI-RS, and is according to at least one of Alt 2E-<NUM> through Alt 2E-<NUM>.

In one alternative Alt 2F-<NUM>, the set S includes additional values in the set T for both cases when µPDCCH ≥ µCSI-RS and µPDCCH <, where the set T is the same for both cases when µPDCCH ≥ µCSI-RS and µPDCCH < µCSI-RS, and is according to at least one of Alt 2E-<NUM> through Alt 2E-<NUM>.

In one alternative Alt 2F-3a, the set S includes additional values in the set T for both cases when µPDCCH ≥ µCSI-RS and µPDCCH < µCSI-RS, where the set T can be different for both cases when µPDCCH ≥ µCSI-RS and µPDCCH < µCSI-RS, and is according to at least one of Alt 2E-<NUM> through Alt 2E-<NUM>.

In one alternative Alt 2F-<NUM>, the set S includes additional values in the set T only when µPDCCH > µCSI-RS, where the set T is according to at least one of Alt 2E-<NUM> through Alt 2E-<NUM>. When µPDCCH < µCSI-RS, the set S = {<NUM>,<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>}.

In one alternative Alt 2F-<NUM>, the set S includes additional values in the set T only when µPDCCH < µCSI-RS, where the set T is according to at least one of Alt 2E-<NUM> through Alt 2E-<NUM>. When µPDCCH > µCSI-RS, the set S = {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>}.

In one alternative Alt 2F-<NUM>, the set S includes additional values in the set T only when µPDCCH ≥ µCSI-RS, where the set T is according to at least one of Alt 2E-<NUM> through Alt 2E-<NUM>. When µPDCCH < µCSI-RS, the set S = {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>}.

In one alternative Alt 2F-<NUM>, the set S includes additional values in the set T only when µPDCCH ≤ µCSI-RS, where the set T is according to at least one of Alt 2E-<NUM> through Alt 2E-<NUM>. When µPCCH > µCSI-RS, the set S = {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>,<NUM>}.

In one alternative Alt 2F-<NUM>, the set S includes additional values in the set T only when µPDCCH > µCSI-RS, where the set T is according to at least one of Alt 2E-<NUM> through Alt 2E-<NUM>. When µPDCCH ≤ µCSI-RS, the set S = {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>}.

In one alternative Alt 2F-<NUM>, the set S includes additional values in the set T only when µPDCCH < µCSI-RS, where the set T is according to at least one of Alt 2E-<NUM> through Alt 2E-<NUM>. When µPDCCH ≥ µCSI-RS, the set S = {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>}.

In one embodiment <NUM>, let k be the number of (OFDM) symbols between the end of the PDCCH containing the triggering DCI and the CSI-RS. In order to avoid too short time between DCI decoding and start receiving the triggered CSI-RS at the UE, which could happen if k is too small, the UE processing can be relaxed. At least one of the following embodiments can be used for this purpose.

In one sub-embodiment 3A, the UE does not expect that the SCS associated with the PDCCH carrying the triggering DCI is greater than the CSI-RS SCS, i.e., µPDCCH ≤ µCSI-RS, and the UE processing relaxation is defined in the numerology of the aperiodic CSI-RS, µCSI-RS. In one example, the UE processing relaxation is performed regardless of the values for µPDCCH and µCSI-RS. In another example, when µPDCCH = µCSI-RS, no processing relaxation is performed, and when µPDCCH < µCSI-RS, the UE processing relaxation is performed according to at least one of the following examples.

In one example 3A-<NUM>, the UE does not expect that the PDCCH carrying the triggering DCI is contained in the last x symbols of the slot (in CSI-RS numerology), i.e., k ≥ x. In one example, x = <NUM>.

In one example 3A-<NUM>, the UE is not required to process aperiodic CSI-RS there are less than <MAT> or <MAT> or <MAT> symbols between the end of the PDCCH containing the triggering DCI and the beginning of CSI-RS, i.e., <MAT> or <MAT> or <MAT>. Here, m is defined according to at least one of Alt1A-<NUM>, Alt1A-<NUM>, Alt1A-<NUM>, and Alt1A-<NUM> or m is fixed.

In one example 3A-<NUM>, the CSI-RS triggering offset X is always larger than zero.

In one example 3A-<NUM>, the UE processing is relaxed by y slots in CSI-RS numerology. In one example, y = <NUM>.

In one example 3A-<NUM>, the slot offset is applied as follows.

In one example 3A-<NUM>, the UE processing relaxation is based on choosing an appropriate Beamswitchtiming Y (cf. embodiment <NUM>).

In one example 3A-6a, the UE processing relaxation is based on defining the earliest possible starting point for the CSI-RS transmission/reception (T). In one example, T = the end of the PDCCH + Δ or the end of the PDCCH + Δ × t, where <MAT> or <MAT> or <MAT> and Δ is defined according to at least one of the following examples.

When µ-PDCCH > µCSI-RS, for the UE processing relaxation time (T), the definition Ex 3A-6a-<NUM> is used.

In one example, the Δ value is given by the following:.

In another example, the Δ value is given by the following:.

In another example, the Δ value is given by m × t, where <MAT> or <MAT> or <MAT> and m is fixed, for example, to <NUM>.

In another example, the Δ value is fixed, for example, to <NUM>.

In these examples, the Δ value can either be without the quantization step (Ex 3A-6a-<NUM>) or with the quantization step (Ex 3A-6a-<NUM>).

In one example 3A-<NUM>, the UE processing relaxation depends on the value X ∈ {<NUM>,. ,<NUM>,<NUM>,<NUM>} of aperiodicTriggeringOffset.

In one sub-embodiment 3AA, the UE does not expect that the SCS associated with the PDCCH carrying the triggering DCI is greater than the CSI-RS SCS, i.e., µPDCCH ≤ µCSI-RS, and the UE processing relaxation is defined in the numerology of the PDCCH, µPDCCH. In one example, the UE processing relaxation is performed regardless of the values for µPDCCH and µCSI-RS. In another example, when µPDCCH = µCSI-RS, no process ing relaxation is performed, and when µPDCCH < µCSI-RS, the UE processing relaxation is performed according to at least one of the following examples.

In one example 3AA-<NUM>, the UE does not expect that the PDCCH carrying the triggering DCI is contained in the last x symbols of the slot (in PDCCH numerology), i.e., k ≥ x. In one example, x= <NUM>.

In one example 3AA-<NUM>, the UE is not required to process aperiodic CSI-RS if there are less than <MAT> or <MAT> or <MAT> symbols between the end of the PDCCH containing the triggering DCI and the beginning of CSI-RS, i.e., <MAT> or <MAT> or <MAT>. Here, m is defined according to at least one of Alt1A-<NUM>, Alt1A-<NUM>, and Alt1A-<NUM> or m is fixed.

In one example 3AA-<NUM>, the CSI-RS triggering offset X is always larger than zero.

In one example 3AA-<NUM>, the UE processing is relaxed by y slots in PDCCH numerology. In one example, y = <NUM>.

In one example 3AA-<NUM>, the slot offset is applied as follows.

In one example 3AA-<NUM>, the UE processing relaxation is based on choosing an appropriate Beamswitchtiming Y (cf. embodiment <NUM>).

In one example 3AA-6a, the UE processing relaxation is based on defining the earliest possible starting point for the CSI-RS transmission/reception (T). In one example, T = the end of the PDCCH + Δ, or the end of the PDCCH + Δ ×t, where <MAT> or <MAT> or <MAT> and Δ is defined according to at least one of the following examples.

When µPDCCH > µCSI-RS, for the UE processing relaxation time (T), the definition Ex 3AA-6a-<NUM> is used.

In another example, the Δ value is fixed, for example, to <NUM> or <NUM>.

In these examples, the Δ value can either be without the quantization step (Ex 3AA-6a-<NUM>) or with the quantization step (Ex 3AA-6a-<NUM>).

In example 3AA-<NUM>, the UE processing relaxation depends on the value X ∈ {<NUM>,. ,<NUM>,<NUM>,<NUM>} of aperiodicTriggeringOffset.

In one sub-embodiment 3B, there is no restriction on PDCCH and CSI-RS SCSs, i.e., µPDCCH and µCSI-RS can take any values, and the UE processing relaxation is defined in the numerology of the aperiodic CSI-RS µCSI-RS. The rest of the details are the same as or analogous to those in sub-embodiment 3A/3AA (including all examples and alternatives) except that the condition "if the PDCCH SCS is equal the CSI-RS SCS (µPDCCH = µCSI-RS)" in some of the above examples (example 3A-<NUM>/3AA-<NUM> through example 3A-<NUM>/3AA-<NUM>) is replaced with the condition "if the PDCCH SCS is larger than or equal the CSI-RS SCS (µPDCCH ≥ µCSI-RS)".

In one sub-embodiment 3C, there is no restriction on PDCCH and CSI-RS SCSs, i.e., µPDCCH and µCSI-RS can take any values. The UE processing relaxation is defined based on the maximum subcarrier spacing between the PDCCH and the aperiodic CSI-RS. Hence, when µPDCCH ≤ µCSI-RS, the UE processing relaxation is defined in the numerology of the aperiodic CSI-RS µCSI-RS and the rest of the details are the same as or analogous to those in sub-embodiment 3A (including all examples and alternatives). When µPDCCH > µCSI-RS, the UE processing relaxation is defined in the numerology of the PDCCH µPDCCH and the rest of the details are the same as or analogous to those in sub-embodiment 3A (including all examples and alternatives) except that µCSI-RS and µPDCCH are swapped everywhere, i.e., µCSI-RS is replaced with µPDCCH and µPDCCH is replaced withµCSI-RS.

In one sub-embodiment 3D, there is no restriction on PDCCH and CSI-RS SCSs, i.e., µPDCCH and µCSI-RS can take any values. The UE processing relaxation is defined based on the minimum subcarrier spacing between the PDCCH and the aperiodic CSI-RS. Hence, when µPDCCH > µCSI-RS, the UE processing relaxation is defined in the numerology of the aperiodic CSI-RS µCSI-RS and the rest of the details are the same as or analogous to those in sub-embodiment 3A (including all examples and alternatives). When µPDCCH ≤ µCSI-RS, the UE processing relaxation is defined in the numerology of the PDCCH µPDCCH and the rest of the details are the same as or analogous to those in sub-embodiment 3A (including all examples and alternatives) except that µCSI-RS and µPDCCH are swapped everywhere, i.e., µCSI-RS is replaced with µPDCCH and µPDCCH is replaced with µCSI-RS.

In one embodiment 4A, the PDCCH containing the triggering DCI triggers anAP-SRS transmission by the UE. The embodiments <NUM> through <NUM> (onAP-CSI-RS reception) can be used (analogously) for AP-SRS transmission by the UE in a straightforward manner.

Regarding AP-SRS, for a UE configured with one or more SRS resource configuration(s), and when the higher layer parameter resourceType in SRS-Resource is set to 'aperiodic':.

<MAT> where k is configured via higher layer parameter slotOffset for each triggered SRS resources set and is based on the subcarrier spacing of the triggered SRS transmission, µSRS and µPDCCH are the subcarrier spacing configurations for triggered SRS and PDCCH carrying the triggering command respectively.

According to this embodiment, the minimal time interval in units of OFDM symbols is counted based on the minimum subcarrier spacing between the PDCCH and the aperiodic SRS. Alternatively, the minimal time interval between the last symbol of the PDCCH triggering the aperiodic SRS transmission and the first symbol of SRS resource is t = N<NUM> +z× p or t = (N<NUM> + z) × p, where z = <NUM> for SRS in a resource set with usage set to 'codebook' or 'antennaSwitching', and z = X > <NUM> otherwise (i.e., for SRS in a resource set with usage set to 'nonCodebook' or 'beamManagement'). In one example X= <NUM>. The parameter p is determined according to at least one of the following examples.

In one example, <MAT> or <MAT> or <MAT> or <MAT> or <MAT>.

In another example, p = (<NUM>µSRS-µPDCCH) or <MAT> or p = <MAT>.

Likewise, if the UE receives the DCI triggering aperiodic SRS in slot n, the UE transmits aperiodic SRS in each of the triggered SRS resource set(s) in slot n' + k where k is configured via higher layer parameter slotOffset for each triggered SRS resources set and n' is determined according to at least one examples 2A-<NUM> through 2A-<NUM> except that µCSI-RS needs to be replaced with µSRS in these examples.

In one embodiment 4B, the PDCCH containing the triggering DCI triggers an aperiodic DL RS (e.g., CSI-RS) reception by the UE. The embodiments <NUM> through <NUM> (on AP-CSI-RS recept ion) can be used (analogously) for aperiodic DL RS (e.g., CSI-RS) reception by the UE in a straightforward manner.

In one embodiment 4C, the PDCCH containing the triggering DCI triggers an aperiodic UL RS (e.g., SRS) transmission by the UE. The embodiments <NUM> through <NUM> (on AP-CSI-RS reception) can be used (analogously) for aperiodic UL RS (e.g., SRS) transmission by the UE in a straightforward manner.

The UE may be configured with non-codebook based UL transmission when the higher layer parameter txConfig is set to 'nonCodebook'.

For non-codebook based transmission, PUSCH can be scheduled by DCI format 0_0, DCI format 0_1 or semi-statically configured to operate. The UE can determine its PUSCH precoder and transmission rank based on the SRI when multiple SRS resources are configured, where the SRI is given by the SRS resource indicator in DCI, or the SRI is given by srs-Resourcelndicator. The UE may use one or multiple SRS resources for SRS transmission, where, in an SRS resource set, the maximum number of SRS resources which can be configured to the UE for simultaneous transmission in the same symbol and the maximum number of SRS resources are UE capabilities. In one example, only one SRS port for each SRS resource is configured. In one example, only one SRS resource set can be configured with higher layer parameter usage in SRS-ResourceSet set to 'nonCodebook'. In one example, the maximum number of SRS resources that can be configured for non-codebook based uplink transmission is <NUM>. The indicated SRI in slot n is associated with the most recent transmission of SRS resource(s) identified by the SRI, where the SRS transmission is prior to the PDCCH carrying the SRI.

For non-codebook based transmission, the UE can calculate the precoder used for the transmission of SRS based on measurement of an associated NZP CSI-RS resource. A UE can be configured with only one NZP CSI-RS resource for the SRS resource set with higher layer parameter usage in SRS-ResourceSet set to 'nonCodebook' if configured.

In the following embodiments on this component, we assume that the UE is configured with a SRS resource set, and associatedCSI-RS in SRS-ResourceSet for the SRS resource set for non-codebook based UL transmission, the details of which are as explained above. We further assume that SRS resource(s) in the SRS resource set are configured to be aperiodic.

In one embodiment 5A, the PDCCH containing the DCI triggers AP-SRS where the AP-SRS is associated with an AP-CSI-RS (e.g., AP-CSI-RS can be received by the UE to obtain beamforming/precoding information for pre-coded AP-SRS transmission). In one example, AP-CSI-RS is associated with an AP-SRS via higher layer configuration (this is pertinent when DL-UL beam correspondence or reciprocity holds). At least one of embodiments <NUM>-<NUM>, or sub-embodiments therein, can be used (analogously) for aperiodic CSI-RS transmission in this case. The DCI triggering aperiodic CSI-RS can be DL-related DCI or UL-related DCI.

Let µPDCCH, µCSI-RS, and µSRS, respectively, be the subcarrier spacing configurations for PDCCH, CSI-RS, and SRS. In the following embodiment, the subcarrier spacing configurations for PDCCH and CSI-RS are the same, i.e., µPDCCH = µCSI-RS, and that for SRS can be different from PDCCH/CSI-RS.

In one embodiment 5B, the PDCCH containing the DCI triggers AP-SRS where the AP-SRS is associated with an AP-CSI-RS (e.g., AP-CSI-RS can be received by the UE to obtain beamforming/precoding information for pre-coded AP-SRS transmission). In one example, AP-CSI-RS is associated with an AP-SRS via higher layer configuration (this is pertinent when DL-UL beam correspondence or reciprocity holds).

Regarding the QCL assumption for SRS transmission, the UE is not expected to be configured with 'QCL-Type D' which indicates spatial filtering information (the spatial filtering information is instead derived based on AP-CSI-RS associated with the AP-SRS).

Since CSI-RS is located in the same slot as PDCCH, the slot offset between PDCCH and CSI-RS is zero.

The minimal time interval between the last symbol of the PDCCH triggering the aperiodic SRS transmission and the first symbol of SRS resource is determined according to at least one example/alternative in embodiment 4A.

The slot offset between PDCCH and SRS transmission is determined according to at least one example/alternative in embodiment 4A.

The processing time between AP-CSI-RS reception and AP-SRS transmission needs to be such that the UE can derive/calculate the updated SRS precoding information after AP-CSI-RS reception. At least one of the following examples is used for the processing time.

* In one example 5B-<NUM>, a UE is not expected to update the SRS precoding information if the gap from the last symbol of the reception of the aperiodic NZP-CSI-RS resource and the first symbol of the aperiodic SRS transmission is less than Z OFDM symbols. In one alternative, Z is fixed (e.g., <NUM>). In another alternative, Z is configured to the UE.

* In one example 5B-<NUM>, a UE is not expected to update the SRS precoding information if the gap from the last symbol of the reception of the aperiodic NZP-CSI-RS resource and the first symbol of the aperiodic SRS transmission is less than Z OFDM symbols, where the OFDM symbols is counted based on the minimum subcarrier spacing between the PDCCH (or AP-CSI-RS) and the AP-SRS. In one alternative, Z is fixed (e.g., <NUM>). In another alternative, Z is configured to the UE.

In 3GPP NR specification, the UL transmission is configured to be either codebook-based or non-codebook-based via higher layer parameter txConfig in PUSCH-Config set to either "codebook" or "nonCodebook.

According to 3GPP NR specification, the following is supported for codebook based UL transmission. For codebook based transmission, the UE determines the UE' s codebook subsets based on TPMI and upon the reception of higher layer parameter ULCodebookSubset or codebookSubset in PUSCH-Config which may be configured with "fullAndPartialAndNonCoherent," or "partialAndNonCoherent," or "nonCoherent" depending on the UE capability. The maximum transmission rank may be configured by the higher parameter ULmaxRank or maxRank in PUSCH-Config.

A UE reporting the UE' s UE capability of "partialAndNonCoherent" transmission may not expect to be configured by ULCodebookSubset with "fullAndPartialAndNonCoherent.

A UE reporting the UE' s UE capability of "Non-Coherent" transmission may not expect to be configured by ULCodebookSubset with "fullAndPartialAndNonCoherent" or with "partialAndNonCoherent.

A UE may not expect to be configured with the higher layer parameter ULCodebookSubset set to "partialAndNonCoherent" when two antenna ports are configured.

In the present disclosure, "fullAndPartialAndNonCoherent," "part i a I AndNonCoherent " and "Non-Coherent" are referred to as the three examples of coherence type/capability, where the term "coherence" implies a subset of antenna ports at the UE that can be used to transmit a layer of UL data coherently.

According to NR specification, for non-codebook-based UL transmission, the precoding matrix W equals the identity matrix. For codebook-based UL transmission, the precoding matrix W isgivenby W = <NUM> for single-layer transmission on a single antenna port, otherwise by TABLE <NUM> to TABLE <NUM>.

The subset of TPMI indices for the three coherence types are summarized in TABLE <NUM> and TABLE <NUM> where rank = r corresponds to (and is equivalent to) r layers.

The rank (or number of layers) and the corresponding precoding matrix W are indicated to the UE using TRI and TPMI, respectively. In one example, this indication is joint via a field "Precoding information and number of layers" in DCI, e.g., using DCI format 0_1. In another example, this indication is via higher layer RRC signaling. In one example, the mapping between a field "Precoding information and number of layers" and TRI/TPMI is according to NR.

In one embodiment 6A1, a UE is configured with a low-resolution dual-stage codebook C<NUM> for codebook-based UL transmission where the codebook C<NUM> comprises precoding matrices W = W1W2, where.

An example of such a codebook is NR Type I CSI codebook.

In one embodiment 6A2, a UE is configured with a high-resolution dual-stage codebook C<NUM> for codebook-based UL transmission where the codebook C<NUM> comprises precoding matrices W = W1W2, where.

An example of such a codebook is NR Type II CSI codebook. Another example of such as codebook is that W1 is (potentially oversampled) DFT codebook and W2 is NR UL codebook (either all or a subset of pre-coder/pre-coding matrices).

If both R'<NUM> and W2 are indicated by the gNB to the UE, then at least one of the following alternatives is used for the indication.

If only W1 is indicated by the gNB to the UE (e.g. when W2 is determined by the UE in a transparent manner), then at least one of the following alternative is used for the indication.

If only W2 is indicated by the gNB to the UE (e.g. when W1 is determined by the UE in a transparent manner), then at least one of the following alternative is used for the indication.

The W1 indication is in a WB manner, i.e., a single W1 is indicated common for all scheduled PRBs/SBs for UL transmission. The W2 indication, on the other hand, can either be in a WB manner or per SB, i. , one W2 is indication for each scheduled PRB/SB.

The W1 indication can be via UL-related DCI (e.g. , DCI format 0_1 in NR). Alternatively, it is via higher-layer (e.g., RRC) signaling.

Alternatively, the W1 indication is via PDSCH. Likewise, the W2 indication can be via UL-related DCI (e.g., DCI format 0_1 in NR). Alternatively, the W2 indication is via higher-layer (e.g., RRC) signaling. Alternatively, the W2 indication is via PDSCH.

In one alternative, the value L in UL codebooks (C<NUM> and C<NUM>) is fixed, for example, L = <NUM> for C<NUM> and L = <NUM> for C<NUM>. In another alternative, the value L in UL codebooks (C<NUM> and C<NUM>) is configured (e.g. via higher layer RRC signaling), for example, from {<NUM>,<NUM>}.

In one example, when L = <NUM> for C<NUM>, the UL codebook is the same as NR Type I codebook for Codebook-Config <NUM>.

In one example, when L = <NUM> for C<NUM>, the UL codebook is the same as Rel. <NUM> Type II codebook, except that there can be some additional restrictions such as either one or any combination of the following restrictions.

<FIG> illustrates a method for a partial reciprocity based scheme <NUM> according to embodiments of the present disclosure. The embodiment of the partial reciprocity based scheme <NUM> illustrated in <FIG> is for illustration only. <FIG> does not limit the scope of this disclosure to any particular implementation of the partial reciprocity based scheme <NUM>.

In one embodiment <NUM>, a UE is configured with codebook-based UL transmission according to the method illustrated in <FIG>. As illustrated in <FIG>, The UE receives higher-layer configuration to transmit NSRS ≥ <NUM> SRS resources. In response, the UE transmits SRS resources according to the configuration. The gNB measures these SRS resources, est imates UL channel based on the SRS measurement, and then determines/calculates W1 (indicating a group of precoders/beams). The UE receives an indication about W1 (from the gNB). The UE next receives a configuration about CSI-RS measurement (for W2 calculation). The UE receives/measures CSI-RS, estimates DL channel, and (assuming reciprocity) uses it as UL channel for W2 calculation. The UE finally transmits UL transmission using pre-coder/pre-coding matrix W =W1W2, where W1 is indicated by the gNB, and W2 is determined by the UE. Since W2 is transparent to the gNB/NW, the UE can calculate W2 for each scheduled PRB/SB for UL transmission, i.e., the UL precoding can be applied in a per PRB/SB manner.

Since W1 is a WB component of the pre-coding matrix W, it can be indicated via higher layer (e.g. RRC) signaling. Alternatively, W1 is indicated via UL-related DCI (e.g. DCI format 0_1 in NR). Also, W1 indication can be via a separate UL-related DCI parameter. Or, this indication can be via an existing UL-related DCI parameter such as TPMI or SRI.

The W1 indication can correspond to a fixed rank (transmit rank indicator or TRI) value, for example, rank <NUM>. Or, a rank (TRI) value is also indicated jointly with the W1 indication. Or, a rank (TRI) value is also indicated separately from the W1 indication. In the latter case, at least one of the following indication alternatives can be used.

The W2 calculation at the UE either follows rank indicated via TRI or has a fixed rank (e.g. rank <NUM>). In an alternative, TRI is indicated via higher layer signaling, and W1 and W2 are calculated/indicated accordingly.

The other UL-related parameters such as MCS can be indicated joint ly with the W1 indication. Or, they are indicated via a separate indication (e.g., via DCI).

The SRS and CSI-RS resources can be linked (or associated with each other) via higher layer configuration of parameters such as associatedSRS in CSI-RS-ResourceSet for CSI-RS resource and associatedCSI-RS in SRS-ResourceSet for SRS resource.

<FIG> illustrates another method for a partial reciprocity based scheme <NUM> according to embodiments of the present disclosure. The embodiment of the partial reciprocity based scheme <NUM> illustrated in <FIG> is for illustration only. <FIG> does not limit the scope of this disclosure to any particular implementation of the partial reciprocity based scheme <NUM>.

In one embodiment 7A, as illustrated in <FIG>, which is a variation of embodiment <NUM>, the UE is further configured to transmit W2 to the gNB which uses it to determine parameters such as MCS for UL transmission assuming W = W1W2 as UL pre-coder/pre-coding matrix. The UE receives MCS (e.g., via UL-related DCI) and transmits UL data accordingly.

<FIG> illustrates yet another method for a partial reciprocity based scheme <NUM> according to embodiments of the present disclosure. The embodiment of the partial reciprocity based scheme <NUM> illustrated in <FIG> is for illustration only. <FIG> does not limit the scope of this disclosure to any particular implementation of the partial reciprocity based scheme <NUM>.

In one embodiment <NUM>, as illustrated in <FIG>, a UE is configured with codebook-based UL transmission. The UE receives a configuration (e.g., via higher layer signaling) about CSI-RS measurement (for W1 calculation). The UE receives/measures CSI-RS, estimates DL channel, and (assuming reciprocity) uses it as UL channel for W1 calculation. The calculated W1 is used to pre-code NSRS ≥ <NUM> SRS resources, whose configuration is received by the UE via higher layer signaling, either jointly with or separate from CSI-RS configuration. The UE transmits SRS resources (pre-coded with W1) according to the configuration. The gNB measures these SRS resources, estimates UL channel based on the SRS measurement, and then determines/calculates W2 component of the UL pre-coder. The UE receives an indication about W2 (from the gNB). The UE finally transmits UL transmission using pre-coder/pre-coding matrix W =W1W2, where W2 is indicated by the gNB (hence, it is non-transparent), and W1 is determined by the UE (hence, it is transparent).

The W2 indication can be WB, i.e., a single W2 is indicated for all scheduled PRBs/SBs for UL transmission. Alternatively, the gNB/NW can calculate W2 for each scheduled PRB/SB for UL transmission, i.e., the UL precoding can be applied in a per PRB/SB manner.

The use of multiple pre-coded SRS resources (that are pre-coded using W1 der ived based on CSI-RS measurement) can, for instance, be for captur ing UL channel rank space or avoiding UL channel null space.

In one sub-embodiment <NUM>-<NUM>, NSRS = X, and each SRS resource comprises <NUM> port. The W2 indicates a pre-coder which combines all X SRS ports (equivalently, all precoders/beams in W1) for each layer using the W2 of high-resolution codebook C<NUM> in embodiment A2.

In one sub-embodiment <NUM>-<NUM>, NSRS = <NUM>, and the SRS resource comprises X port. The W2 indicates a pre-coder which combines all X SRS ports (equivalently, all precoders/beams in W1) for each layer using the W2 of high-resolution codebook C<NUM> in embodiment A2.

In one sub-embodiment <NUM>-<NUM>, NSRS = Y, and each SRS resource comprises X/Y ports. The W2 indicates a pre-coder which combines all X SRS ports (equivalent ly, all precoders/beams in W1) for each layer using the W2 of high-resolution codebook C<NUM> in embodiment A2.

In one sub-embodiment <NUM>-<NUM>, NSRS = X, and each SRS resource comprises <NUM> port. The W2 indicates a pre-coder which selects <NUM> out of X SRS ports (equivalently, <NUM> precoder/beam in W1) for each layer using the W2 of low-resolution codebook C<NUM> in embodiment A1.

In one sub-embodiment <NUM>-<NUM>, NSRS = <NUM>, and the SRS resource comprises X port. The W2 indicates a pre-coder which selects <NUM> out of X SRS ports (equivalently, <NUM> precoder/beam in W1) for each layer using the W2 of low-resolution codebook C<NUM> in embodiment A1.

In one sub-embodiment <NUM>-<NUM>, NSRS = Y, and each SRS resource comprises X/Y ports. The W2 indicates a pre-coder which selects <NUM> out of X SRS ports (equivalently, <NUM> precoder/beam in W1) for each layer using the W2 of low-resolution codebook C<NUM> in embodiment A1.

The W2 indication is according to one of Alt 6A-<NUM>, 6A-<NUM>, and 6A-<NUM>. Alternatively, a generalized (joint) SRI can be used to indicate both SRS resource selection and W2 for the selected SRS resources. That is, this generalized SRI essentially functions as a TPMI across the selected SRS resources. Alternatively, generalized (joint) TPMI can be used to indicate both SRS resource selection and W2 for the selected SRS resources. That is, this general ized TPMI essentially functions as a TPMI across the selected SRS resources. Alternatively, a SRI can be used to indicate SRS resource selection, and TPMI can be used to indicate W2 for the selected SRS resources.

The W2 indication can correspond to a fixed rank (transmit rank indicator or TRI) value, for example, rank <NUM>. Or, a rank (TRI) value is also indicated jointly with the W2 indication. Or, a rank (TRI) value is also indicated separately from the W2 indication. In the latter case, at least one of the following indication alternatives can be used.

The W1 calculation at the UE has a fixed rank (e.g., rank <NUM>). In an alternative, TRI is indicated via higher layer signaling, and W1 and W2 are calculated/indicated accordingly.

In one embodiment 8A, a variation of embodiment <NUM>, the UE is configured to transmit W1 to the gNB and SRS resources (that are not pre-coded with W1), which uses them to determine parameters such as MCS for UL transmission assuming W = W1W2 as UL pre-coder/pre-coding matrix. The UE receives MCS (e.g. via UL-related DCI) and transmits UL data accordingly.

<FIG> illustrates still another method for a partial reciprocity based scheme <NUM> according to embodiments of the present disclosure. The embodiment of the partial reciprocity based scheme <NUM> illustrated in <FIG> is for illustration only. <FIG> does not limit the scope of this disclosure to any particular implementation of the partial reciprocity based scheme <NUM>.

In one embodiment <NUM>, as illustrated in <FIG>, a UE is configured with codebook-based UL transmission. The UE receives higher-layer configuration for the first SRS transmission comprising NSRS,<NUM> ≥ <NUM> SRS resources. In response, the UE transmits the first SRS resources according to the configuration. The gNB measures these SRS resources, estimates UL channel based on the SRS measurement, and then determines/calculates W1 (indicating a group of precoders/beams). The UE receives an indication about W1 (from the gNB). The UE also receives higher-layer configuration for the second SRS transmission comprising NSRS,<NUM> ≥ <NUM> SRS resources, either jointly with or separate from the first SRS configuration. The UE transmits the second SRS resources (pre-coded with W1) according to the configuration. The gNB measures these SRS resources, estimates UL channel based on the SRS measurement, and then determines/calculates W2 component of the UL pre-coder. The UE receives an indication about W2 (from the gNB). The UE finally transmits UL transmission using pre-coder/pre-coding matrix W = W1W2.

The first SRS resources may or may not be pre-coded, but the second SRS resources are pre-coded based on W1 (e.g. via TPMI1). The rank (TRI) indication can be according to at least one of the following alternatives.

In one alternative Alt <NUM>-<NUM> (with W1): TRI is indicated either jointly or separately with the W1 indication (e.g. vi a TPMI <NUM>). The W2 indication either follows rank indicated via TRI or has a fixed rank (e.g. rank <NUM>).

In one alternative Alt <NUM>-<NUM> (with W2): TRI is indicated either jointly or separately with the W2 indication (e.g. via TPMI2). The W1 indication can assume a fixed rank (e.g. rank <NUM>).

In one alternative Alt <NUM>-<NUM> (with both W1 and W2): both TRI1 and TRI <NUM> are indicated.

<FIG> illustrates a flow chart of a method <NUM> for operating a user equipment (UE) for aperiodic channel state information reference signal (CSI-RS) reception, as may be performed by a UE such as UE <NUM>, according to embodiments of the present disclosure. The embodiment of the method <NUM> illustrated in <FIG> is for illustration only. <FIG> does not limit the scope of this disclosure to any particular implementation.

As illustrated in <FIG>, the method <NUM> begins at step <NUM>. In step <NUM>, the UE (e.g., <NUM>-<NUM> as illustrated in <FIG>) receives aperiodic CSI-RS configuration information including a CSI-RS triggering offset.

In step <NUM>, the UE receives downlink control information (DCI) via a physical downlink control channel (PDCCH), where the DCI triggers an aperiodic CSI-RS.

In step <NUM>, the UE determines the CSI-RS triggering offset based on the CSI-RS configuration information. The CSI-RS triggering offset is configured from a first set when µPDCCH < µCSIRS, and the CSI-RS triggering offset is configured from a second set when µPDCCH > µCSIRS, wherein µPDCCH and µCSIRS are subcarrier spacing configurations for the PDCCH and the aperiodic CSI-RS, respectively.

In step <NUM>, the UE receives the aperiodic CSI-RS in a slot Ks determined based on the CSI-RS triggering offset, a slot containing the triggering DCI, and the subcarrier spacing configurations (µPDCCH and µCSIRS).

In one embodiment, the first set is {<NUM>, <NUM>, <NUM>,. <NUM>} and the second set is {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>}.

In one embodiment, the slot <MAT>, where n is the slot containing the triggering DCI, X is the CSI-RS triggering offset, and └ ┘ is a floor function.

In one embodiment, the processor is further configured to determine a starting orthogonal frequency-division multiplexing (OFDM) symbol for the aperiodic CSI-RS reception, and the transceiver is further configured to start the aperiodic CSI-RS reception from the start ing OFDM symbol. For µPDCCH < µCSIRS, the start ing OFDM symbol is determined such that the CSI-RS reception starts no earlier than a first OFDM symbol of a CSI-RS slot that starts at least Δ PDCCH symbols after an end of the PDCCH triggering the aperiodic CSI-RS. For µPDCCH > µCSIRS, the starting OFDM symbol is determined such that the CSI-RS reception starts no earlier than at least Δ PDCCH symbols after the end of the PDCCH triggering the aperiodic CSI-RS.

In one embodiment, when µPDCCH = <NUM> indicating subcarrier spacing of <NUM>, Δ = <NUM>.

In one embodiment, the processor is further configured to determine a quasi co-location (QCL) assumption for the aperiodic CSI-RS reception based on a condition on a scheduling offset δ between a last symbol of the PDCCH triggering the aperiodic CSI-RS and a first symbol of the aperiodic CSI-RS, where the condition is given by, when δ < α, the QCL assumption is a QCL assumption for a PDSCH, if the PDSCH is received in the same OFDM symbols as the aperiodic CSI-RS, and the QCL assumption is a QCL assumption for a PDCCH, otherwise, when δ ≥ α, the QCL assumption is indicated via the PDCCH triggering the aperiodic CSI-RS. The transceiver is further configured to apply the determined QCL assumption for the aperiodic CSI-RS reception, where α is a threshold and the QCL assumption corresponds to QCL-TypeD indicating a beam to receive the aperiodic CSI-RS.

In one embodiment, the threshold <MAT>, wherein Y is a UE reported threshold beamSwitchTiming taken from a set that includes {<NUM>, <NUM>, <NUM>}, and wherein d is an additional delay such that d = <NUM> when µPDCCH ≥ µCSIRS and d = m when µPDCCH < µCSIRS.

In one embodiment, when µPDCCH = <NUM> indicating a subcarrier spacing of <NUM>, m = <NUM>; when µPDCCH = <NUM> indicating a subcarrier spacing of <NUM>, m = <NUM>; and when µPDCCH = <NUM> indicating a subcarrier spacing of <NUM>, m = <NUM>.

<FIG> illustrates a flow chart of another method <NUM>, as may be performed by a base stat ion (BS) such as BS <NUM>, according to embodiments of the present disclosure. The embodiment of the method <NUM> illustrated in <FIG> is for illustration only. <FIG> does not limit the scope of this disclosure to any particular implementation.

As illustrated in <FIG>, the method <NUM> begins at step <NUM>. In step <NUM>, the BS (e.g., <NUM>-<NUM> as illustrated in <FIG>), generates an aperiodic channel state information reference signal (CSI-RS) configuration information and a downlink control information (DCI).

In step <NUM>, the BS transmits the aperiodic CSI-RS configuration information including a CSI-RS triggering offset.

In step <NUM>, the BS transmits the DCI via a physical downlink control channel (PDCCH), where the DCI triggers an aperiodic CSI-RS.

In step <NUM>, the BS transmits the aperiodic CSI-RS in a slot Ks.

The CSI-RS triggering offset is configured from a first set when µPDCCH < µCSIRS, and from a second set when µPDCCH > µCSIRS, where µPDCCH and µCSIRS are subcarrier spacing configurations for the PDCCH and the aperiodic CSI-RS, respectively. The slot Ks is determined based on the CSI-RS triggering offset, a slot containing the triggering DCI, and the subcarrier spacing configurations (µPDCCH and µCSIRS).

In one embodiment, the slot <MAT>, where n is the slot containing the triggering DCI, X is the CSI-RS triggering offset, and └┘ is a floor function.

In one embodiment, a starting orthogonal frequency-division multiplexing (OFDM) symbol for an aperiodic CSI-RS reception is determined based on the CSI-RS configuration information, and the aperiodic CSI-RS reception is started from the start ing OFDM symbol. For µPDCCH < µCSIRS, the start ing OFDM symbol is determined such that the CSI-RS reception starts no earlier than a first OFDM symbol of a CSI-RS slot that starts at least Δ PDCCH symbols after an end of the PDCCH triggering the aperiodic CSI-RS. For µPDCCH > µCSIRS, the starting OFDM symbol is determined such that the CSI-RS reception starts no earlier than at least Δ PDCCH symbols after the end of the PDCCH triggering the aperiodic CSI-RS.

In one embodiment, when µPDCCH = <NUM> indicating a subcarrier spacing of <NUM>, Δ = <NUM>.

In one embodiment, a quasi co-location (QCL) assumption for aperiodic CSI-RS reception is determined based on a condition on a scheduling offset δ between a last symbol of the PDCCH triggering the aperiodic CSI-RS and a first symbol of the aperiodic CSI-RS, where the condition is given by, when δ < α, the QCL assumption is a QCL assumption for a PDSCH, if the PDSCH is received in the same OFDM symbols as the aperiodic CSI-RS, and the QCL assumption is a QCL assumption for a PDCCH, otherwise, when δ ≥ α, the QCL assumption is indicated via the PDCCH triggering the aperiodic CSI-RS; and the determined QCL assumption for the aperiodic CSI-RS reception is applied, where α is a threshold and the QCL assumption corresponds to QCL-TypeD indicating a beam to receive aperiodic CSI-RS.

Claim 1:
A terminal (<NUM>) in a wireless communication system, the terminal (<NUM>) comprising:
a transceiver (<NUM>) configured to transmit and receive a signal; and
a controller (<NUM>) coupled with the transceiver (<NUM>) and configured to:
receive, from a base station (<NUM>), a radio resource control, RRC, message including configuration information on channel state information reference signal, CSI-RS, resources, the configuration information including an aperiodic triggering offset X in units of slots,
receive, from the base station (<NUM>), a physical downlink control channel, PDCCH, triggering an aperiodic channel state information, CSI, reporting in a first slot n<NUM>, and
receive, from the base station (<NUM>), an aperiodic CSI-RS in a second slot n<NUM> based on the configuration information and the PDCCH,
wherein a first numerology of the PDCCH µ<NUM> and a second numerology of the aperiodic CSI-RS µ<NUM> are different from each other,
wherein the second slot is identified based on the first slot and the aperiodic triggering offset, and
wherein the second slot n<NUM> is identified as a slot <MAT>, where X is in the second numerology µ<NUM>.