Apparatus and method for determining coherence time between transmit antennas

Abstract

Various aspects of this disclosure relate to: determining (702) at a user equipment (UE) the coherence time between at least two transmit antennas of the UE, ensuring that the transmission is coherent during the coherence time; and transmitting (704) the coherence time to a network device, such as transmitting the coherence time to a base station.

Description

Technical Field

[0001] This disclosure relates to wireless communication, and more specifically, to determining the coherence time between transmitting antennas. Background Technology

[0002] A wireless communication system may include one or more network communication devices, such as base stations, which can support wireless communication with one or more user communication devices (which may also be referred to as user equipment (UE) or other suitable terms). The wireless communication system can support wireless communication with one or more user communication devices by utilizing the resources of the wireless communication system (e.g., time resources (e.g., symbols, time slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers, or the like)). Furthermore, the wireless communication system can support wireless communication across various radio access technologies, including third-generation (3G) radio access technology, fourth-generation (4G) radio access technology, fifth-generation (5G) radio access technology, and other suitable radio access technologies beyond 5G (e.g., sixth-generation (6G)). Summary of the Invention

[0003] The article “a” preceding an element is unrestricted and should be understood to refer to “at least one” or “one or more” of these elements. As used herein, the terms “a,” “at least one,” “one or more,” and “at least one of one or more” are interchangeable. As used herein (including in the claims), the word “or” used in a list of items (e.g., a list of items beginning with phrases such as “at least one of…”, “one or more of…”, or “one or both of…”) indicates an inclusive list, such that (e.g.) a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Furthermore, as used herein, the phrase “based on” should not be construed as referring to a closed set of conditions. For example, without departing from the scope of this disclosure, an exemplary step described as “based on condition A” may be based on both condition A and condition B. In other words, as used herein, the phrase “based on” should be interpreted in the same manner as the phrase “at least partially based on.” Furthermore, as used herein (included in the claims), a “group” may comprise one or more elements.

[0004] Some implementations of the methods and apparatus described herein may further include: determining the coherence time between at least two transmit antennas of the UE, ensuring that the transmission is coherent during the coherence time; and transmitting the coherence time to a network device. Attached Figure Description

[0005] Figure 1 Examples of wireless communication systems according to aspects of this disclosure are described.

[0006] Figure 2A This describes an example of a precoding matrix W used for single-layer transmission with four antenna ports when transform precoding is enabled.

[0007] Figure 2B This describes an example of a precoding matrix W used for two-layer transmission with four antenna ports when transform precoding is disabled.

[0008] Figure 3 Examples illustrating antenna amplitude and phase.

[0009] Figure 4 Examples of UEs based on aspects of this disclosure are described.

[0010] Figure 5 Examples of processors according to aspects of this disclosure are described.

[0011] Figure 6 Examples of network equipment (NE) according to aspects of this disclosure are described.

[0012] Figure 7 A flowchart illustrating a method performed by a UE according to aspects of this disclosure.

[0013] Figure 8 A flowchart illustrating the method performed by NE according to aspects of this disclosure. Detailed Implementation

[0014] Various aspects of this disclosure relate to a system for determining the coherence time between at least two transmit antennas, ensuring that the transmission is coherent within the coherence time. The coherence time can be transmitted to a network device.

[0015] The aspects of this disclosure are described in the context of wireless communication systems.

[0016] Figure 1This describes an example of a wireless communication system 100 according to aspects of this disclosure. The wireless communication system 100 may include one or more NEs 102, one or more UEs 104, and a core network (CN) 106. The wireless communication system 100 may support various radio access technologies. In some embodiments, the wireless communication system 100 may be a 4G network, such as an LTE network or an LTE-A network. In some other embodiments, the wireless communication system 100 may be a New Radio (NR) network, such as a 5G network, a 5G-A network, or a 5G Ultra Wideband (5G-UWB) network. In other embodiments, the wireless communication system 100 may be a combination of 4G and 5G networks or other suitable radio access technologies, including IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), and IEEE 802.20. The wireless communication system 100 may support radio access technologies beyond 5G, such as 6G. In addition, the wireless communication system 100 can support technologies such as Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), or Code Division Multiple Access (CDMA).

[0017] One or more NEs 102 may be distributed throughout a geographic area to form a wireless communication system 100. One or more of the NEs 102 described herein may be, include, or be referred to as a network node, base station, network element, network function, network entity, wireless access network (RAN), NodeB, eNodeB (eNB), next-generation NodeB (gNB), or other suitable terms. NEs 102 and UEs 104 may communicate via a communication link, which may be wireless or wired. For example, NEs 102 and UEs 104 may perform wireless communication (e.g., receiving signaling, transmitting signaling) via a Uu interface.

[0018] NE 102 can provide a geographic coverage area for which NE 102 can support services for one or more UE 104s within the geographic coverage area. For example, NE 102 and UE 104 can support wireless communication of signals associated with services (e.g., voice, video, packet data, messaging, broadcasting, etc.) according to one or more radio access technologies. In some embodiments, NE 102 can be mobile, such as a satellite associated with a non-terrestrial network (NTN). In some embodiments, different geographic coverage areas associated with the same or different radio access technologies may overlap, but different geographic coverage areas may be associated with different NE 102s.

[0019] One or more UEs 104 may be distributed throughout the geographic area of ​​the wireless communication system 100. UE 104 may include or be referred to as a remote unit, mobile device, wireless device, remote device, subscriber device, transmitter device, receiver device, or some other suitable term. In some embodiments, UE 104 may be referred to as a unit, station, terminal, or client, and other instances thereof. Alternatively or additionally, UE 104 may be referred to as an Internet of Things (IoT) device, Internet of Everything (IoE) device, or Machine-Type Communication (MTC) device, and other instances thereof.

[0020] UE 104 may be able to support direct wireless communication with other UE 104 via a communication link. For example, UE 104 may support direct wireless communication with another UE 104 via a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link may be referred to as a sidelink. For example, UE 104 may support direct wireless communication with another UE 104 via a UE-to-UE interface (PC5 interface).

[0021] NE 102 may support communication with CN 106 or another NE 102, or both. For example, NE 102 may interface with other NE 102 or CN 106 via one or more backhaul links (e.g., S1, N2, N2, or network interfaces). In some implementations, NE 102 may communicate directly with each other. In some other implementations, NE 102 may communicate with each other indirectly (e.g., via CN 106). In some implementations, one or more NE 102 may include sub-components, such as access network entities, which may be instances of Access Node Controllers (ANCs). The ANC may communicate with one or more UE 104s via one or more other access network transmitting entities, which may be referred to as radio headends, smart radio headends, or transmit-receive points (TRPs).

[0022] CN 106 can support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. CN 106 can be an evolved packet core (EPC) or a 5G core (5GC), which may include control plane entities that manage access and mobility (e.g., Mobility Management Entity (MME), Access and Mobility Management (AMF) functions) and user plane entities (e.g., Serving Gateway (S-GW), Packet Data Network (PDN) Gateway (P-GW), or User Plane Function (UPF)) that route packets to or interconnect to external networks. In some implementations, the control plane entities may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signaling bearers, etc.) of one or more UEs 104 served by one or more NEs 102 associated with CN 106.

[0023] CN 106 can communicate with a packet data network (e.g., via S1, N2, N2, or another network interface) through one or more backhaul links. The packet data network may contain an application server. In some implementations, one or more UEs 104 can communicate with the application server. UE 104 can establish a session (e.g., a Protocol Data Unit (PDU) session or the like) with CN 106 via NE 102. CN 106 can use the established session (e.g., an established PDU session) to route traffic (e.g., control information, data, and the like) between UE 104 and the application server. A PDU session may be an instance of a logical connection between UE 104 and CN 106 (e.g., one or more network functions of CN 106).

[0024] In the wireless communication system 100, NE 102 and UE 104 can use the resources of the wireless communication system 100 (e.g., time resources (e.g., symbols, time slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers)) to perform various operations (e.g., wireless communication). In some embodiments, NE 102 and UE 104 may support different resource structures. For example, NE 102 and UE 104 may support different frame structures. In some embodiments, such as in 4G, NE 102 and UE 104 may support a single frame structure. In some other embodiments, such as in 5G and other suitable radio access technologies, NE 102 and UE 104 may support various frame structures (i.e., multiple frame structures). NE 102 and UE 104 may support various frame structures based on one or more sets of parameters.

[0025] The wireless communication system 100 may support one or more parameter sets, and the parameter sets may include subcarrier spacing and cyclic prefixes. A first parameter set (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a regular cyclic prefix. In some embodiments, the first parameter set (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one time slot per subframe. A second parameter set (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a regular cyclic prefix. A third parameter set (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a regular cyclic prefix or an extended cyclic prefix. A fourth parameter set (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a regular cyclic prefix. A fifth parameter set (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a regular cyclic prefix.

[0026] Time intervals for resources (such as communication resources) can be organized according to frames (also known as radio frames). Each frame may have a duration, for example, 10 milliseconds (ms). In some implementations, each frame may contain multiple subframes. For example, each frame may contain 10 subframes, and each subframe may have a duration, for example, 1 ms. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

[0027] Alternatively, the time intervals of resources (e.g., communication resources) can be organized according to time slots. For example, a subframe may contain a certain number (e.g., a set of parameters). The number of time slots in each subframe may also depend on one or more parameter sets supported in the wireless communication system 100. For example, the first, second, third, fourth, and fifth parameter sets (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with corresponding subcarrier intervals of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz can respectively utilize one time slot per subframe, two time slots per subframe, four time slots per subframe, eight time slots per subframe, and 16 time slots per subframe. Each time slot may contain a certain number (e.g., a set of parameters) of symbols (e.g., Orthogonal Frequency Division Multiplexing (OFDM) symbols). In some embodiments, the number (e.g., quantity) of time slots in a subframe may depend on the parameter set. For a conventional cyclic prefix, a time slot may contain 14 symbols. For an extended cyclic prefix (e.g., applicable to a 60 kHz subcarrier spacing), a time slot may contain 12 symbols. The relationship between the number of symbols per time slot, the number of time slots per subframe, and the number of time slots per frame for the regular and extended cyclic prefixes may depend on the parameter set. It should be understood that references to the first parameter set (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) can be used interchangeably between subframes and time slots.

[0028] In the wireless communication system 100, the electromagnetic (EM) spectrum can be divided into various categories, bands, channels, etc., based on frequency or wavelength. For example, the wireless communication system 100 may support one or more operating frequency bands, such as frequency ranges represented as FR1 (410 MHz to 7.125 GHz), FR2 (24.25 GHz to 52.6 GHz), FR3 (7.125 GHz to 24.25 GHz), FR4 (52.6 GHz to 114.25 GHz), FR4a or FR4-1 (52.6 GHz to 71 GHz), and FR5 (114.25 GHz to 300 GHz). In some embodiments, NE 102 and UE 104 may perform wireless communication on one or more of the operating frequency bands. In some embodiments, FR1 may be used by NE 102 and UE 104, as well as other equipment or devices, for cellular communication services (e.g., control information, data). In some implementations, FR2 can be used by NE 102 and UE 104, as well as other equipment or devices, for short-range, high data rate capabilities.

[0029] FR1 can be associated with one or more parameter sets (e.g., at least three parameter sets). For example, FR1 can be associated with: a first parameter set (e.g., μ=0) containing a 15 kHz subcarrier spacing; a second parameter set (e.g., μ=1) containing a 30 kHz subcarrier spacing; and a third parameter set (e.g., μ=2) containing a 60 kHz subcarrier spacing. FR2 can be associated with one or more parameter sets (e.g., at least two parameter sets). For example, FR2 can be associated with: a third parameter set (e.g., μ=2) containing a 60 kHz subcarrier spacing; and a fourth parameter set (e.g., μ=3) containing a 120 kHz subcarrier spacing.

[0030] In one configuration, coherent uplink (UL) multiple-input multiple-output (MIMO) requirements can be defined as found herein. For coherent UL MIMO, Table 1 shows the maximum permissible difference between the relative power and phase error measured between different antenna connectors in any time slot within a specified time window from the last sounding reference signal (SRS) transmitted at the same antenna connector for uplink transmission (codebook or non-codebook use), and the relative power and phase error measured at the last SRS. The requirements in Table 1 apply to SRS transmission and time window duration when the UL transmit power at each antenna connector is greater than 0 dBm.

[0031] Table 1: Maximum permissible difference between relative phase and power errors in a given time slot and relative phase and power errors measured at the last SRS of the transmission.

[0032]

[0033] The requirements in Table 1 can be used if all of the following conditions are met within the specified time window: 1) The UE is not signaled a change in the number of SRS ports in the SRS-config or a change in the PUSCH-config; 2) The UE remains in discontinuous reception (DRX) active time (e.g., the UE does not enter DRX OFF time); 3) No measurement gaps occur; 4) No instances of SRS transmissions using antenna switching occur; 5) The active bandwidth portion (BWP) remains the same; 6) The UE's evolved non-independent dual connectivity (EN-DC) and carrier aggregation (CA) configurations remain unchanged (e.g., the UE is not configured or is deconfigured for primary / secondary cell (PSCell) or secondary cell (SCell)); and 7) when the UE is not configured for uplink handover; or when the UE is configured for uplink handover and supports a 'fullCoherent' codebook subset in the corresponding carrier according to the capabilities uplinkTxSwitching-PUSCH-TransCoherence and / or uplinkTxSwitching2T2T-PUSCH-TransCoherence; or when the UE is configured for uplink handover and supports a 'nonCoherent' codebook subset in the corresponding carrier according to the capabilities uplinkTxSwitching-PUSCH-TransCoherence and / or uplinkTxSwitching2T2T-PUSCH-TransCoherence and the uplink handover is not triggered by a handover mechanism between the last transmitted SRS and the scheduled transmission.

[0034] The coherent uplink requirement can be interpreted as follows:

[0035] set up This represents the amplitude and phase at the i-th antenna connector at the start of the k-th 20 msec interval, where It is a real value, where , It is a real value and lies in the interval In the middle. So...

[0036] .

[0037] The relative phase requirement can be evaluated as follows. Let...

[0038] .

[0039] The relative phase requirement is met if the following conditions are met.

[0040] .

[0041] Similar expressions can be derived. For example, the relative phase requirement can also be expressed as...

[0042] .

[0043] More generally, the relative phase requirement of K degrees can be expressed as

[0044] .

[0045] As mentioned above, the relative phase requirement can also be expressed as

[0046] .

[0047] The requirements stated above may have several drawbacks. First, the UE can only signal whether it meets or does not meet the requirements. The UE cannot indicate, for example, that it can meet a better (smaller) relative phase change requirement or a better (smaller) relative gain change requirement, or that it can meet the existing requirements for a longer period than 20 ms. For example, if the gNB knows that the UE can meet the coherence requirement for a longer period, then the gNB may schedule SRS transmissions less frequently. Conversely, if the UE cannot meet the relative phase change or relative gain requirement within 20 ms, but can meet it within 10 ms, then the gNB may choose to configure the UE for uplink MIMO, but schedule SRS transmissions more frequently. The reason for configuring uplink MIMO even if the UE cannot meet the 20 ms requirement is that, depending on the transmission rank, the UE may not be able to meet the power class without transmitting from multiple antennas.

[0048] Therefore, it may be beneficial to allow the UE to indicate some granularity regarding time intervals, relative gain changes, and relative phase change requirements. For example, signaling could be used to indicate both relative gain changes and time periods during which the relative gain change is valid. Similarly, signaling could be used to indicate the maximum relative phase change and time periods during which the relative phase change is valid.

[0049] As is understood, using signaling to indicate time intervals, relative gain changes, and / or relative phase changes can have several advantages, such as:

[0050] First, for transmissions below full rank, the UE may not be able to transmit at full power unless at least some of the antenna ports are coherent. Consider an example with four antenna ports, each with a power amplifier having a power equal to one-quarter of the power class's power. For a full-power, rank-one transmission, it must transmit from all four antenna ports. However, to transmit from all four antenna ports using uplink MIMO, the four antenna ports must be coherent with each other. If only two ports are coherent with each other, then the maximum achievable power for a single-layer transmission is equal to half the power class. Alternatively, if none of the ports are coherent with each other, then the maximum transmittable power is equal to one-quarter of the power class.

[0051] Figure 2A This describes an example of a precoding matrix W 200 used for single-layer transmission using four antenna ports with transform precoding enabled. If none of the antenna ports are coherent, then only precoders 0 through 3 can be used, and therefore the maximum transmittable power is equal to one-quarter of the power class power. If the first and third antenna ports are coherent, then precoders 4 through 7 can be used, and if the second and fourth antenna ports are coherent, then precoders 8 through 11 can be used. For any of precoders 4 through 11, the maximum transmittable power is equal to half the power class power. Finally, if all four antenna ports are coherent, then precoders 12 through 27 can be used. For these precoders, the maximum transmittable power is equal to the power class power.

[0052] Also about Figure 2B Similar observations were made of the two layers of precoders in the model. Figure 2B This describes an example of a precoding matrix W 250 used for two-layer transmission with four antenna ports when transform precoding is disabled. Two-layer non-phase-interfering encoders 0 to 6 can only use two of the four power amplifiers (PAs), and therefore can only satisfy half of the power class. However, two-layer partially phase-interfering encoders 6 to 13, whose ports 1 and 3 are coherent and whose ports 2 and 4 are coherent, use all four PAs and can satisfy all of the power class. Similarly, phase-interfering encoders 14 to 21 can all satisfy the power class.

[0053] The second reason for defining the signaling is that even without the maximum power issue, coherent uplink MIMO performs better than incoherent or partially coherent uplink MIMO. This is because, for a fixed amount of transmit energy and a fixed number of layers, the signal-to-noise ratio and / or capacity of the signal received at the gNB is greater than that without coherent uplink MIMO. This is because the UE can use multiple antennas to direct the energy transmitted in the gNB direction.

[0054] In situations where the uplink channel is unknown from channel reciprocity or feedback from the gNB, antenna patterns generated when transmitting from multiple antenna ports in the MIMO layer can have beams whose direction relative to the gNB is unknown. Therefore, the gNB may be located within the zero-gain or low-gain region of the UE's antenna pattern. As the number of antenna ports increases, the generated antenna pattern will have a narrower beam, which further increases the likelihood that the gNB will fall within the zero-gain or low-gain region of the UE's antenna pattern.

[0055] The following observations can be made based on the benefits of the signaling described herein: 1) To achieve maximum UE transmit power, it may be necessary to transmit from as many antenna ports as possible—for uplink MIMO, the precoder for a given layer may only have non-zero values ​​for antenna ports that are coherent with each other; 2) For a fixed amount of transmit energy and a fixed number of layers, the signal-to-noise ratio and / or capacity of the signal received at the gNB junction is greater in the case of coherent uplink MIMO than in partially coherent uplink MIMO, incoherent uplink MIMO, or transparent transmit diversity; and 3) While transparent transmit diversity can achieve power classes, its performance can be highly unpredictable because the implementation is unspecified. For example, cyclic delays or linear delays may or may not be used, and if used, the delay may not be specified. Furthermore, performance can depend on the delay used, the carrier bandwidth, and the bandwidth of the resource allocation.

[0056] In some configurations, it may be beneficial to extend the range of coherent operation as much as possible in order to increase the maximum transmit power and to maximize the signal-to-noise ratio and / or capacity for a given transmit power. This can be done if the gNB has a better understanding of the limitations of coherent operation for the UE.

[0057] In some configurations, if the UE coherence time is less than 20 ms, which normally disallows coherent operation, the UE can signal the actual coherence time, and the gNB can configure the UE to transmit SRS more frequently, so that the UE can be configured to use coherent uplink MIMO.

[0058] Conversely, if the UE coherence time is greater than 20 msec, the gNB can be configured to transmit SRS less frequently, and if the UE speed is low, the UE can still be configured for coherent uplink MIMO, so that the channel between the gNB and the UE changes relatively slowly.

[0059] Figure 3 This section provides an example illustrating antenna amplitude and phase 30°.

[0060] Therefore, signaling can be used to enable the UE to signal the maximum coherence time that can meet the existing relative phase and relative gain requirements.

[0061] Uplink MIMO codebooks used in frequency range 1 (e.g., FR1 410 MHz to 7125 MHz) can have a phase resolution of 90 degrees (e.g., 1, -1, j, -j), but finer phase resolution can be used at the upper end of this frequency range or for new bands located above FR1 but below frequency range 2 (e.g., FR2-1 24250 MHz to 52600 MHz and FR2-2 52600 MHz to 71000 MHz). If finer frequency phase resolution codebooks are used in these regions, it may be necessary to tighten the coherence requirements for phase and / or gain. For example, if the phase resolution of the codebook is reduced to 45 degrees, the phase coherence requirement can be reduced to less than half of this value or less than 22.5 degrees.

[0062] In various configurations, signaling may be used to allow the UE to indicate the relative phase and relative gain requirements it can satisfy within a 20 msec interval from the last SRS transmission and / or the relative gain and phase requirements it can satisfy within any defined interval. If more stringent (e.g., smaller) relative gain and phase requirements are defined for a new codebook, signaling may be used to allow the UE to indicate the maximum time interval within which the more stringent relative phase and gain requirements can be satisfied.

[0063] In certain configurations, the following signaling capabilities may be beneficial to both the UE and system performance: 1) for a given relative phase requirement, signaling can be used to indicate the maximum time that the requirement can be met; 2) for a given relative gain requirement, signaling can be used to indicate the maximum time that the requirement can be met; 3) for a given time interval, signaling can be used to indicate the minimum relative phase tolerance that can be met; and / or 4) for a given time interval, signaling can be used to indicate the minimum relative gain tolerance that can be met.

[0064] Figure 4 An example of a UE 400 according to aspects of this disclosure is described. UE 400 may include a processor 402, a memory 404, a controller 406, and a transceiver 408. The processor 402, memory 404, controller 406, or transceiver 408, or various combinations thereof, or various components thereof, may be examples of components for performing the aspects of this disclosure described herein. These components may be coupled via one or more interfaces (e.g., operatively, communicatively, functionally, electronically, or electrically).

[0065] Processor 402, memory 404, controller 406, or transceiver 408, or various combinations or components thereof, may be implemented in hardware (e.g., a circuit system). The hardware may include processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), or other programmable logic devices, or any combination thereof configured or otherwise supporting components for performing the functions described in this disclosure.

[0066] Processor 402 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, ASICs, field-programmable gate arrays (FPGAs), or any combination thereof). In some embodiments, processor 402 may be configured to operate memory 404. In some other embodiments, memory 404 may be integrated into processor 402. Processor 402 may be configured to execute computer-readable instructions stored in memory 404 to cause UE 400 to perform various functions of this disclosure.

[0067] Memory 404 may comprise volatile or non-volatile memory. Memory 404 may store computer-readable, computer-executable code containing instructions that, when executed by processor 402, cause UE 400 to perform the various functions described herein. The code may be stored in a non-transitory computer-readable medium, this memory 404, or another type of memory. Computer-readable medium includes both non-transitory computer storage media and communication media, including any media that facilitates the transfer of computer programs from one place to another. Non-transitory storage media may be any available media accessible by a general-purpose or special-purpose computer.

[0068] In some implementations, processor 402 and memory 404 coupled to processor 402 may be configured to cause UE 400 to perform one or more of the functions described herein (e.g., processor 402 executing instructions stored in memory 404). For example, processor 402 may support wireless communication at UE 400 according to the examples disclosed herein.

[0069] Controller 406 manages the input and output signals of UE 400. Controller 406 can also manage peripheral devices not integrated into UE 400. In some embodiments, controller 406 may utilize an operating system, such as iOS®, Android®, Windows®, or other operating systems. In some embodiments, controller 406 may be implemented as part of processor 402.

[0070] In some embodiments, UE 400 may include at least one transceiver 408. In other embodiments, UE 400 may have more than one transceiver 408. Transceiver 408 may represent a wireless transceiver. Transceiver 408 may include one or more receiver chains 410, one or more transmitter chains 412, or a combination thereof.

[0071] Receiver chain 410 may be configured to receive signals (e.g., control information, data, packets) via wireless media. For example, receiver chain 410 may include one or more antennas for receiving signals over the air or wireless media. Receiver chain 410 may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. Receiver chain 410 may include at least one demodulator configured to demodulate the received signal and obtain transmitted data by reversing the modulation technique applied during signal transmission. Receiver chain 410 may include at least one decoder for decoding and processing the demodulated signal to receive transmitted data.

[0072] Transmitter chain 412 can be configured to generate and transmit signals (e.g., control information, data, packets). Transmitter chain 412 may include at least one modulator for modulating data onto a carrier signal in preparation for transmission over a wireless medium. At least one modulator may be configured to support one or more techniques, such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes like phase shift keying (PSK) or quadrature amplitude modulation (QAM). At least one modulator may be configured to support Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) modulation or Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) modulation. Transmitter chain 412 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over a wireless medium. Transmitter chain 412 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

[0073] Figure 5 An example of a processor 500 according to aspects of this disclosure is described. Processor 500 may be an example of a processor configured to perform various operations according to the examples described herein. Processor 500 may include a controller 502 configured to perform various operations according to the examples described herein. Processor 500 may optionally include at least one memory 504, which may be, for example, an L1 / L2 / L3 cache. Additionally or alternatively, processor 500 may optionally include one or more arithmetic logic units (ALUs) 506. One or more of these components may be electronically communicated or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses).

[0074] Processor 500 may be a processor chipset and includes a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receive, acquire, retrieve, transmit, output, forward, store, determine, identify, access, write, read) according to the examples described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to the processor chipset (e.g., processor 500) or included in the processor chipset) or other memory (e.g., random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), static RAM (SRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, phase-change memory (PCM), and others).

[0075] Controller 502 can be configured to manage and coordinate various operations of processor 500 (e.g., signaling, receiving, acquiring, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, and reading) to enable processor 500 to support various operations according to the examples described herein. For example, controller 502 can operate as a control unit of processor 500, generating control signals that manage the operation of various components of processor 500. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating operation timing.

[0076] Controller 502 may be configured to fetch (e.g., fetch, retrieve, receive) instructions from memory 504 and determine subsequent instructions to be executed to enable processor 500 to support various operations according to the examples described herein. Controller 502 may be configured to track the memory addresses of instructions associated with memory 504. Controller 502 may be configured to decode instructions to determine the operations to be performed and the operands involved. For example, controller 502 may be configured to interpret instructions and determine control signals to be output to other components of processor 500 to enable processor 500 to support various operations according to the examples described herein. Alternatively or additionally, controller 502 may be configured to manage data flow within processor 500. Controller 502 may be configured to control data transfers between registers, arithmetic logic unit (ALU), and other functional units of processor 500.

[0077] Memory 504 may include one or more caches (e.g., memory local to or included in processor 500) or other memories, such as RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some embodiments, memory 504 may reside within or on the processor chipset (e.g., locally to processor 500). In some other embodiments, memory 504 may reside outside the processor chipset (e.g., remotely from processor 500).

[0078] Memory 504 may store computer-readable, computer-executable code containing instructions that, when executed by processor 500, cause processor 500 to perform the various functions described herein. The code may be stored in a non-transitory computer-readable medium, such as system memory or another type of memory. Controller 502 and / or processor 500 may be configured to execute the computer-readable instructions stored in memory 504 to cause processor 500 to perform various functions. For example, processor 500 and / or controller 502 may be coupled to or coupled to memory 504, and processor 500, controller 502, and memory 504 may be configured to perform the various functions described herein. In some instances, processor 500 may include multiple processors, and memory 504 may include multiple memories. One or more of the multiple processors may be coupled to one or more of the multiple memories, which may be individually or jointly configured to perform the various functions described herein.

[0079] One or more ALU 506s may be configured to support various operations according to the examples described herein. In some embodiments, one or more ALU 506s may reside within or on a processor chipset (e.g., processor 500). In some other embodiments, one or more ALU 506s may reside outside the processor chipset (e.g., processor 500). One or more ALU 506s may perform one or more computations on data, such as addition, subtraction, multiplication, and division. For example, one or more ALU 506s may receive input operands and opcodes, which determine the operation to be performed. One or more ALU 506s are configured with various logic and arithmetic circuitry, including adders, subtractors, shifters, and logic gates, to process and manipulate data according to the operation. Alternatively, one or more ALU 506s may support logical operations such as AND, OR, XOR, NOR, and NAND, enabling one or more ALU 506s to handle conditional operations, comparisons, and bitwise operations.

[0080] Processor 500 can support wireless communication according to the examples disclosed herein. Processor 500 can be configured or operable to support components for: determining the coherence time between at least two transmit antennas of the UE, ensuring that the transmission is coherent during the coherence time; and transmitting the coherence time to a network device.

[0081] Figure 6 An example of NE 600 according to aspects of this disclosure is described. NE 600 may include a processor 602, a memory 604, a controller 606, and a transceiver 608. The processor 602, memory 604, controller 606, or transceiver 608, or various combinations thereof, or various components thereof, may be examples of components for performing the aspects of this disclosure described herein. These components may be coupled via one or more interfaces (e.g., operatively, communicatively, functionally, electronically, electrically).

[0082] Processor 602, memory 604, controller 606, or transceiver 608, or various combinations or components thereof, may be implemented in hardware (e.g., a circuit system). The hardware may include processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), or other programmable logic devices, or any combination thereof configured or otherwise supporting components for performing the functions described in this disclosure.

[0083] Processor 602 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, ASICs, FPGAs, or any combination thereof). In some embodiments, processor 602 may be configured to operate memory 604. In some other embodiments, memory 604 may be integrated into processor 602. Processor 602 may be configured to execute computer-readable instructions stored in memory 604 to cause NE 600 to perform various functions of this disclosure.

[0084] Memory 604 may comprise volatile or non-volatile memory. Memory 604 may store computer-readable, computer-executable code containing instructions that, when executed by processor 602, cause NE 600 to perform the various functions described herein. The code may be stored in a non-transitory computer-readable medium, this memory 604, or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media, encompassing any media that facilitates the transfer of computer programs from one place to another. Non-transitory storage media may be any available media accessible by a general-purpose or special-purpose computer.

[0085] In some implementations, processor 602 and memory 604 coupled to processor 602 may be configured to cause NE 600 to perform one or more of the functions described herein (e.g., processor 602 executing instructions stored in memory 604). For example, processor 602 may support wireless communication at NE 600 according to the examples disclosed herein.

[0086] Controller 606 manages the input and output signals of NE 600. Controller 606 can also manage peripheral devices not integrated into NE 600. In some embodiments, controller 606 may utilize an operating system such as iOS®, Android®, Windows®, or other operating systems. In some embodiments, controller 606 may be implemented as part of processor 602.

[0087] In some embodiments, NE 600 may include at least one transceiver 608. In other embodiments, NE 600 may have more than one transceiver 608. Transceiver 608 may represent a wireless transceiver. Transceiver 608 may include one or more receiver chains 610, one or more transmitter chains 612, or a combination thereof.

[0088] Receiver chain 610 may be configured to receive signals (e.g., control information, data, packets) via wireless media. For example, receiver chain 610 may include one or more antennas for receiving signals over the air or wireless media. Receiver chain 610 may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. Receiver chain 610 may include at least one demodulator configured to demodulate the received signal and obtain transmitted data by reversing the modulation technique applied during signal transmission. Receiver chain 610 may include at least one decoder for decoding and processing the demodulated signal to receive transmitted data.

[0089] Transmitter chain 612 can be configured to generate and transmit signals (e.g., control information, data, packets). Transmitter chain 612 may include at least one modulator for modulating data onto a carrier signal in preparation for transmission over a wireless medium. At least one modulator may be configured to support one or more techniques, such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes like phase shift keying (PSK) or quadrature amplitude modulation (QAM). At least one modulator may be configured to support Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) modulation or Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) modulation. Transmitter chain 612 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over a wireless medium. Transmitter chain 612 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

[0090] Figure 7 A flowchart illustrating method 700 according to an aspect of this disclosure is provided. Operation of method 700 may be implemented by a UE, as described herein. In some embodiments, the UE 400 may execute a set of instructions to control functional elements of the processor to perform the described functions.

[0091] In 702, the method may include determining the coherence time between at least two transmit antennas of the UE, during which transmission is guaranteed to be coherent. Operation of 702 may be performed according to the examples described herein. In some embodiments, aspects of the operation of 702 may be described by reference to... Figure 4 The UE execution described.

[0092] In 704, the method may include transmitting coherent time to a network device. The operation of 704 may be performed according to the examples described herein. In some embodiments, aspects of the operation of 704 may be described by reference. Figure 4 The UE execution described.

[0093] Figure 8 A flowchart illustrating another method 800 according to an aspect of this disclosure is provided. The operation of method 800 may be implemented by an NE, as described herein. In some embodiments, the NE 600 may execute a set of instructions to control the functional elements of the processor to perform the described functions.

[0094] In 802, the method may include a coherence time between at least two transmit antennas of the receiving UE, during which the transmission is guaranteed to be coherent. Operation of 802 may be performed according to the examples described herein. In some embodiments, aspects of operation of 802 may be described by reference to... Figure 6 The described NE execution.

[0095] It should be noted that the methods described herein describe possible implementations, and the operations and steps may be rearranged or otherwise modified, and other implementations are possible.

[0096] The description herein is provided to enable those skilled in the art to make or use this disclosure. Various modifications to this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but should be given the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A user equipment (UE) comprising: At least two transmitting antennas; At least one memory; and At least one processor, coupled to and configured to enable the UE to: Determine the coherence time between the at least two transmitting antennas, ensuring that the transmission is coherent within the coherence time; and The coherent time is transmitted to the network device.

2. The UE of claim 1, wherein the coherence time includes a period in which the relative phase difference between the at least two transmit antennas changes less than the maximum phase difference.

3. The UE of claim 1, wherein the coherence time includes the period in which the relative gain difference between the at least two transmit antennas varies less than the maximum gain difference.

4. The UE according to claim 1, wherein the coherence time depends on the modulation type.

5. The UE according to claim 1, wherein the coherence time depends on the number of transmit layers.

6. The UE of claim 1, wherein the coherence time depends on the frequency band.

7. A processor for wireless communication, comprising: At least one controller, coupled to at least one memory and configured to enable the processor to: Determine the coherence time between at least two transmit antennas, ensuring that the transmission is coherent within said coherence time; and The coherent time is transmitted to the network device.

8. The processor of claim 7, wherein the coherence time includes a period in which the relative phase difference between the at least two transmit antennas changes less than the maximum phase difference.

9. The processor of claim 7, wherein the coherence time includes a period in which the relative gain difference between the at least two transmit antennas varies less than the maximum gain difference.

10. The processor of claim 7, wherein the coherence time depends on the modulation type.

11. The processor of claim 7, wherein the coherence time depends on the number of emitter layers.

12. A method performed by a user equipment (UE), the method comprising: Determine the coherence time between at least two transmit antennas of the UE, ensuring that the transmission is coherent within the coherence time; and The coherent time is transmitted to the network device.

13. A network device comprising: At least one memory; and At least one processor, coupled to the at least one memory and configured to enable the network device to: The coherence time between at least two transmit antennas of the user equipment (UE) is received, during which the transmission is guaranteed to be coherent.

14. The network apparatus of claim 13, wherein the coherence time includes a period in which the relative phase difference between the at least two transmit antennas changes less than the maximum phase difference.

15. The network apparatus of claim 13, wherein the coherence time includes a period in which the relative gain difference between the at least two transmit antennas varies less than the maximum gain difference.

16. The network device of claim 13, wherein the coherence time depends on the modulation type.

17. The network apparatus of claim 13, wherein the coherence time depends on the number of transmission layers.

18. The network apparatus of claim 13, wherein the coherence time depends on the frequency band.

19. The network apparatus of claim 13, wherein the at least one processor is configured to cause the network apparatus to determine whether to configure the UE for coherent uplink multiple-input multiple-output MIMO in response to the coherence time being greater than a threshold.

20. The network apparatus of claim 13, wherein the at least one processor is configured to enable the network apparatus to determine the periodicity of the UE's probe reference symbol transmission based on the coherence time.

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