Systems and Methods for Phase Noise Reduction in the Extremely High Frequency Spectrum

Abstract

The present disclosure presents various techniques to improve phase-tracking reference signal (PTRS) performance with respect to extremely high frequency communications. According to some embodiments, enhanced power boosting may be applied to improve PTRS performance while still keeping the power spectral density (PSD) within the ETSI broadband radio access network (BRAN) limits. In some cases, the power boosting may be semi-static and / or dynamic. In other embodiments, improved performance may be achieved by dynamically changing the time and / or frequency density of the PTRS. In other embodiments, a multi-port configuration may be used for downlink PTRS. In other embodiments, one or more PTRS configurations may be determined based on the SCS and / or frequency band, e.g., based on the communication traffic type, channel priority, parameters signaled in the slot format indicator (SFI), etc. In other embodiments, a common phase error (CPE) estimate may be obtained for those OFDM symbols without PTRS by interpolating available PTRS estimates in the time domain.

Description

Technical Field

[0001] This application relates to wireless devices and, more particularly, to apparatuses, systems, and methods for handling phase noise (PN) in the extremely high frequency spectrum (e.g., millimeter wave (MMW or mmWave) spectrum) in a wireless communication system. Background Art

[0002] The use of wireless communication systems is growing rapidly. In recent years, wireless devices such as smart phones and tablet computers have become increasingly sophisticated. In addition to supporting telephone calls, many mobile devices now also provide access to the Internet, email, text messaging, and navigation using the Global Positioning System (GPS), and are capable of operating sophisticated applications that utilize these features. Additionally, there are many different wireless communication technologies and wireless communication standards. Some examples of wireless communication standards include GSM, UMTS (e.g., associated with the WCDMA or TD-SCDMA air interfaces), LTE, LTE-Advanced (LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), BLUETOOTH TM etc.

[0003] The introduction of an increasing number of features and functions in wireless communication devices also requires continuous improvement in wireless communication and in wireless communication devices. To increase coverage and better serve the increasing demands and scope of the intended use of wireless communication, in addition to the above communication standards, there are also wireless communication technologies under development, including fifth-generation (5G) New Radio (NR) communication. Therefore, there is a need to improve the fields that support such development and design. Summary of the Invention

[0004] Embodiments relate to apparatuses, systems, and methods for improving the handling of phase noise (PN) in the extremely high frequency spectrum (e.g., millimeter wave (MMW or mmWave) spectrum) in a wireless communication system such as 5G NR. In 5G NR, millimeter wave refers to the portion of the spectrum within the millimeter wave frequency range, which technically ranges from approximately 30 GHz to 300 GHz. Recent 5G NR research has focused on the bandwidth available at millimeter wave frequencies between 24 GHz and 100 GHz. Signals within the millimeter wave frequency range can be easily absorbed by objects in their propagation path, such as buildings, trees, and human body parts. Successfully handling phase noise has become another issue in designing millimeter wave communication systems. When there is severe phase noise in a communication link, the link performance may degrade substantially. The time unit used to obtain the phase noise estimate determines the ultimate boundary within which the receiver can correct the phase noise. However, millimeter wave signals also offer many beneficial effects, such as larger bandwidth, capacity, faster transmission speed, and smaller antennas. Therefore, it is desirable to utilize techniques to compensate for phase noise in a reliable manner for millimeter wave communication and other extremely high frequency spectrum communications.

[0005] Radio components in a wireless communication device include an oscillator for generating or tuning to a specific radio frequency (RF). A real, i.e., non-ideal, oscillator can experience significant phase noise, which is the random fluctuation in the phase of the waveform generated by the oscillator. As the frequency increases, it may become more difficult to produce an oscillator with good PN characteristics, and thus, PN may become more problematic as the RF frequency increases.

[0006] As described above, in some cases, an RF system can be deployed in an extremely high frequency band up to 100 GHz or higher, where the impact of PN can be very significant. For example, in certain configurations of bandwidth usage, going from 45 GHz to 70 GHz may result in more than four times the amount of expected phase error, which is approximately equal to a 6.4 dB power drop. Generally, studies have shown that PN increases with increasing frequency and with increasing bandwidth.

[0007] In Rel-15, for both downlink communication and uplink communication, specifically for cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) and discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM), a phase tracking reference signal (PT-RS or PTRS) is specified. The PTRS can be used to help compensate for phase shifts. The PTRS can be a pseudo-random sequence. For example, in some embodiments, the PTRS can be based on a 31-stage Gold sequence. A Gold sequence includes 2 n + 1 sequences, with a period of 2 n - 1, and within the Gold sequence, the number of ones and zeros differs by one.

[0008] In an OFDM system transmitted through a flat channel, the PN can be decomposed into two components. The first component is the common phase error (CPE), which is added to each subcarrier and is proportional to the value it multiplies by a complex number. The CPE affects each subcarrier equally and is usually easily corrected by PTRS. The second component is the inter-carrier interference (ICI) error, which is the sum of the information of other subcarriers, each subcarrier multiplied by a complex number, which comes from the average of the phase noise with spectral shift and has the appearance of Gaussian noise. Generally, the ICI is not easily corrected.

[0009] The subcarrier spacing (SCS) selected for a given wireless communication system determines the ratio of CPE to ICI. When the SCS increases, a larger portion of the total PN is CPE and a smaller portion is ICI. Ideally, selecting a very large SCS results in a large, correctable CPE. The PN can also cause a phase shift in the time domain. In the frequency domain, the CPE for all subcarriers may be dominant. Therefore, increasing the SCS can help mitigate the impact of PN, but this may reduce the available bandwidth in the wireless communication system. Additionally, to optimize system performance, it has been determined that the system bandwidth and SCS should preferably not be selected independently of each other.

[0010] In some cases, the amount of frequency bandwidth and / or time for PTRS can be configured (e.g., according to the number of OFDM symbols). The amount of PTRS required in a given scenario can vary, for example, based on the quality of the oscillator used, the carrier frequency, the SCS, the modulation and coding scheme used, etc. In some cases, the PTRS can be configured according to the frequency density and / or time density. The PTRS can be associated with a specific demodulation reference signal (DMRS) port and can be configured to be transmitted within the scheduled bandwidth and duration of the scheduled physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH). In an OFDM system, the PN usually varies over time but tends to be relatively constant over various frequencies. Therefore, according to some embodiments, the PTRS can be configured to be transmitted relatively densely in time but relatively sparsely in frequency.

[0011] The techniques described herein can be implemented in and / or used with multiple different types of devices, including but not limited to any of a cellular phone, a wireless device, a tablet computer, a wearable computing device, a portable media player, and various other computing devices.

[0012] The present invention content aims to provide a brief overview of some of the topics described in this document. Therefore, it should be understood that the above features are only examples and should not be construed as narrowing the scope or essence of the topic described herein in any way. Other features, aspects, and advantages of the topic described herein will become apparent from the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] A better understanding of the subject matter can be obtained when considering the following detailed description of various embodiments in conjunction with the following drawings, in which:

[0014] Figure 1 An exemplary wireless communication system is shown in accordance with some embodiments;

[0015] Figure 2 A base station (BS) communicating with a user equipment (UE) device is shown in accordance with some embodiments;

[0016] Figure 3 An exemplary block diagram of a UE is shown in accordance with some embodiments;

[0017] Figure 4 An exemplary block diagram of a BS is shown in accordance with some embodiments;

[0018] Figure 5 An exemplary block diagram of a cellular communication circuit is shown in accordance with some embodiments;

[0019] Figure 6 An exemplary block diagram of a network element is shown in accordance with some embodiments;

[0020] Figure 7 Various PTRS configurations are shown in accordance with aspects of the present disclosure;

[0021] Figure 8 An exemplary PTRS configuration is shown in accordance with aspects of the present disclosure;

[0022] Figure 9 An exemplary grouped PTRS configuration in the frequency domain is shown in accordance with aspects of the present disclosure;

[0023] Figure 10 A flowchart showing an exemplary technique for phase noise compensation in a wireless system in accordance with aspects of the present disclosure;

[0024] Figure 11 A flowchart showing an exemplary technique for phase noise compensation in a wireless system in accordance with aspects of the present disclosure;

[0025] Figure 12 A flowchart showing an exemplary technique for phase noise compensation in a wireless system in accordance with aspects of the present disclosure;

[0026] Figure 13 is a flowchart showing an exemplary technique for phase noise compensation in a wireless system according to aspects of the present disclosure;

[0027] Figure 14 is a flowchart showing an exemplary technique for phase noise compensation in a wireless system according to aspects of the present disclosure;

[0028] Figure 15 is a flowchart showing an exemplary technique for phase noise compensation in a wireless system according to aspects of the present disclosure;

[0029] Figure 16 is a flowchart showing an exemplary technique for phase noise compensation in a wireless system according to aspects of the present disclosure; and

[0030] Figure 17 is a flowchart showing an exemplary technique for phase noise compensation in a wireless system according to aspects of the present disclosure.

[0031] Although the features described herein may be subject to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and described in detail herein. However, it should be understood that the drawings and the detailed description thereof are not intended to limit the present disclosure to the specific forms disclosed, but on the contrary, are intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the appended claims. Detailed Description

[0032] Various techniques are presented herein to improve PTRS performance compared to Rel-15 and specifically with respect to extremely high frequency (e.g., millimeter wave) communications. According to some embodiments, enhanced power boost can be applied to improve PTRS performance while still keeping the power spectral density (PSD) within the ETSI broadband radio access network (BRAN) limits. In some cases, this power boost can be semi-static and / or dynamic. In other embodiments, improved performance can be achieved by dynamically changing the time / frequency density of the PTRS. In other embodiments, a multi-port configuration can be used for downlink PTRS. In other embodiments, one or more PTRS configurations can be determined based on the SCS and / or frequency band, e.g., based on traffic type, channel priority, parameters signaled in the slot format indicator (SFI) at the start of a time slot, etc. In other embodiments, CPE estimates can be obtained for those OFDM symbols without PTRS by interpolating available PTRS estimates in the time domain.

[0033] The following is a glossary of terms that may be used in the present disclosure:

[0034] Memory medium - Any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include installation media such as CD-ROMs, floppy disks, or magnetic tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media such as hard disk drives or optical storage devices; registers or other similar types of memory elements, etc. The memory medium may also include other types of non-transitory memory or combinations thereof. In addition, the memory medium may be located in a first computer system that executes a program, or may be located in a different second computer system that is connected to the first computer system via a network such as the Internet. In the latter case, the second computer system may provide program instructions to the first computer for execution. The term "memory medium" may include two or more memory media that may reside at different locations in different computer systems connected, for example, via a network. The memory medium may store program instructions (e.g., embodied as a computer program) executable by one or more processors.

[0035] Carrier medium - The storage medium as described above and physical transmission media such as buses, networks, and / or other physical transmission media that convey signals such as electrical, electromagnetic, or digital signals.

[0036] Programmable hardware element - Includes various hardware devices that include a plurality of programmable function blocks connected via programmable interconnects. Examples include FPGAs (Field Programmable Gate Arrays), PLDs (Programmable Logic Devices), FPOAs (Field Programmable Object Arrays), and CPLDs (Complex PLDs). The programmable function blocks can vary from fine-grained (combinational logic components or look-up tables) to coarse-grained (arithmetic logic units or processor cores). Programmable hardware elements may also be referred to as "configurable logic components".

[0037] Computer system - Any of various types of computing systems or processing systems, including personal computer systems (PCs), mainframe computer systems, workstations, network appliances, Internet appliances, personal digital assistants (PDAs), television systems, grid computing systems, or other devices or combinations of devices. Generally, the term "computer system" can be broadly defined to encompass any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

[0038] User equipment (UE) (or "UE device") - Any of various types of computer systems or devices that are mobile or portable and perform wireless communication. Examples of UE devices include mobile phones or smartphones (e.g., iPhone TM, based on Android TM ), portable gaming devices (e.g., Nintendo DS TM , PlayStation Portable TM , Gameboy Advance TM , iPhone TM ), laptop computers, wearable devices (e.g., smartwatches, smart glasses), PDAs, portable Internet devices, music players, data storage devices, or other handheld devices, etc. Generally speaking, the term "UE" or "UE device" can be broadly defined to cover any electronic device, computing device, and / or telecommunications device (or combination of devices) that can be easily transported by a user and is capable of wireless communication.

[0039] Wireless device - Any one of various types of computer systems or devices that perform wireless communication. The wireless device can be portable (or mobile), or can be stationary or fixed in a certain location. A UE is an example of a wireless device.

[0040] Communication device - Any one of various types of computer systems or devices that perform communication, where the communication can be wired or wireless. The communication device can be portable (or mobile), or can be stationary or fixed in a certain location. A wireless device is an example of a communication device. A UE is another example of a communication device.

[0041] Base station - The term "base station" has the full scope of its ordinary meaning and at least includes a wireless communication station that is installed in a fixed location and is used for communication as part of a wireless telephone system or radio system.

[0042] Processing element (or processor) - Refers to various elements or combinations of elements that can execute functions in a device such as a user equipment or a cellular network device. The processing element can include, for example: a processor and associated memory, parts or circuits of individual processor cores, entire processor cores, separate processors, processor arrays, circuits such as ASICs (application-specific integrated circuits), programmable hardware elements such as field-programmable gate arrays (FPGAs), and any one of various combinations thereof.

[0043] Channel - A medium for transmitting information from a transmitter to a receiver. It should be noted that since the characteristics of the term "channel" can vary according to different wireless protocols, the term "channel" used in the present invention can be considered to be used in a manner that conforms to the standards of the type of device to which the term usage refers. In some standards, the channel width can be variable (e.g., depending on device capabilities, frequency band conditions, etc.). For example, LTE can support an expandable channel bandwidth from 1.4 MHz to 20 MHz. In contrast, a WLAN channel can be 22 MHz wide, while a Bluetooth channel can be 1 MHz wide. Other protocols and standards may include different definitions of channels. In addition, some standards can define and use multiple types of channels, such as different channels for uplink or downlink and / or different channels for different purposes such as data, control information, etc.

[0044] Frequency band - The term "frequency band" has the full range of its ordinary meaning and at least includes a segment of the spectrum (e.g., radio frequency spectrum) in which channels are used or reserved for the same purpose.

[0045] Automatically - It means that an action or operation is performed by a computer system (e.g., software executed by a computer system) or a device (e.g., a circuit, a programmable hardware element, an ASIC, etc.) without the action or operation being directly specified or performed through user input. Thus, the term "automatically" is contrary to an operation performed or specified manually by a user, where the user provides input to directly perform the operation. An automatic process can be initiated by input provided by the user, but the subsequent actions performed "automatically" are not specified by the user, i.e., they are not performed "manually", where the user specifies each action to be performed. For example, a user filling out a spreadsheet by selecting each field and providing input to specify information (e.g., by typing information, selecting checkboxes, radio selections, etc.) is manually filling out the form, even though the computer system must update the form in response to the user's action. The form can be filled out automatically by a computer system, where the computer system (e.g., software executed on the computer system) analyzes the fields of the form and fills out the form without any user input specifying the answers to the fields. As indicated above, the user can initiate the automatic filling of the form but does not participate in the actual filling of the form (e.g., the user does not manually specify the answers to the fields but they are completed automatically). This specification provides various examples of operations that are performed automatically in response to actions taken by the user.

[0046] About—means close to a correct or precise value. For example, about can mean a value within 1% to 10% of the exact (or desired) value. However, it should be noted that the actual threshold (or tolerance) may depend on the application. For example, in some embodiments, “about” may mean within 0.1% of some specified or desired value, while in various other embodiments, depending on the expectations or requirements of a particular application, the threshold may be, for example, 2%, 3%, 5%, etc.

[0047] Concurrent—refers to the parallel execution or implementation, where tasks, processes, or programs are executed in at least a partially overlapping manner. For example, “strong” or strict parallelism can be used to achieve concurrency, where tasks are executed (at least partially) in parallel on corresponding computing elements; or “weak parallelism” can be used to achieve concurrency, where tasks are executed in an interleaved manner (e.g., through time multiplexing of execution threads).

[0048] Configured to—various components may be described as “configured to” perform one or more tasks. In such an environment, “configured to” is a broad statement generally meaning “having” the “structure” to perform one or more tasks during operation. Thus, even when the component is not currently performing a task, the component can be configured to perform the task (e.g., a set of electrical conductors can be configured to electrically connect a module to another module, even when the two modules are not connected). In some contexts, “configured to” can be a broad statement generally meaning “having” the “circuitry” to perform one or more tasks during operation. Thus, even when the component is not currently powered on, the component can be configured to perform the task. Generally, the circuitry forming the structure corresponding to “configured to” may include hardware circuitry.

[0049] For ease of description, various components may be described as performing one or more tasks. Such a description should be interpreted to include the phrase “configured to”. A component described as configured to perform one or more tasks is expressly intended not to be interpreted under 35 U.S.C. § 112(f).

[0050] Now turning to Figure 1 , a simplified example of a wireless communication system according to some embodiments is shown. Note that Figure 1 the system of

[0051]

[0052] Base station (BS) 102A can be a transceiver base station (BTS) or a cell site (“cellular base station”), and may include hardware that enables wireless communication with UEs 106A to 106N.

[0053] The communication area (or coverage area) of a base station can be referred to as a “cell”. Base station 102A and UEs 106 can be configured to communicate via a transmission medium using any one of various radio access technologies (RATs), which are also referred to as wireless communication technologies or telecommunication standards, such as GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-Advanced (LTE-A), 5G New Radio (5G-NR), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), and so on. Note that if base station 102A is implemented in an LTE environment, it may alternatively be referred to as an “eNodeB” or “eNB”. Note that if base station 102A is implemented in a 5G NR environment, it may alternatively be referred to as a “gNodeB” or “gNB”.

[0054] As shown, base station 102A can also be equipped to communicate with network 100 (e.g., in various possibilities, the core network of a cellular service provider, a telecommunication network such as the Public Switched Telephone Network (PSTN) and / or the Internet). Thus, base station 102A can facilitate communication between user devices and / or between user devices and network 100. In particular, cellular base station 102A can provide UEs 106 with various communication capabilities such as voice, SMS, and / or data services.

[0055] Base station 102A and other similar base stations operating according to the same or different cellular communication standards (such as base stations 102B......102N) can thus be provided as a network of cells that can provide continuous or nearly continuous overlapping services to UEs 106A-N and similar devices over a geographical area via one or more cellular communication standards.

[0056] Thus, although base station 102A can act as if Figure 1the "serving cell" of the UEs 106A-N shown in the figure, but each UE 106 may also be capable of receiving signals (and may be within its communication range) from one or more other cells (which may be provided by the base stations 102B-N and / or any other base stations), and the one or more other cells may be referred to as "adjacent cells". Such cells may also be capable of facilitating communication between user devices and / or between user devices and the network 100. Such cells may include "macro" cells, "micro" cells, "pico" cells, and / or any other various granularities of cells that provide service area sizes. For example, in Figure 1 the base stations 102A to 102B shown may be macro cells, while the base station 102N may be a micro cell. Other configurations are also possible.

[0057] In some embodiments, the base station 102A may be a next-generation base station, for example, a 5G New Radio (5G NR) base station or a "gNB". In some embodiments, the gNB may be connected to a traditional Evolved Packet Core (EPC) network and / or connected to a NR Core (NRC) / 5G Core (5GC) network. In addition, the gNB cell may include one or more Transmission and Reception Points (TRPs). In addition, a UE capable of operating according to 5G NR may be connected to one or more TRPs within one or more gNBs. For example, the base station 102A and one or more other base stations 102 may support joint transmission, such that the UE 106 may be capable of receiving transmissions from multiple base stations (and / or multiple TRPs provided by the same base station). For example, as Figure 1 shown, both the base station 102A and the base station 102C are shown as serving the UE 106A.

[0058] Note that the UE 106 is capable of communicating using multiple wireless communication standards. For example, in addition to at least one cellular communication protocol (such as GSM, UMTS (associated with, for example, WCDMA or TD-SCDMA air interfaces), LTE, LTE-A, 5G NR, HSPA, 3GPP2 CDMA2000 (such as 1xRTT, 1xEV-DO, HRPD, eHRPD), etc.), the UE 106 may be configured to communicate using wireless networking (such as Wi-Fi) and / or peer-to-peer wireless communication protocols (such as Bluetooth, Wi-Fi peer-to-peer, etc.). If needed, the UE 106 may also or alternatively be configured to communicate using one or more Global Navigation Satellite Systems (GNSS, such as GPS or GLONASS), one or more mobile television broadcast standards (such as Advanced Television Systems Committee-Mobile / Handheld (ATSC-M / H)), and / or any other wireless communication protocol. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0059] Figure 2Illustrated is a user equipment 106 (e.g., one of devices 106A to 106N) communicating with a base station 102 according to some embodiments. The UE 106 can be a device with cellular communication capabilities, such as a mobile phone, a handheld device, a computer, a laptop computer, a tablet computer, a smartwatch, or other wearable devices or virtually any type of wireless device.

[0060] The UE 106 can include a processor (processing element) configured to execute program instructions stored in a memory. The UE 106 can perform any of the method embodiments described in the present invention by executing such stored instructions. Alternatively or additionally, the UE 106 can include programmable hardware elements, such as an FPGA (field programmable gate array), an integrated circuit, and / or any of various other possible hardware components configured to perform (e.g., individually or in combination) any one of the method embodiments described herein or any part of any one of the method embodiments described herein.

[0061] The UE 106 can include one or more antennas for communicating using one or more wireless communication protocols or technologies. In some embodiments, the UE 106 can be configured to communicate using, for example, NR or LTE using at least some shared radio components. As an additional possibility, the UE 106 can be configured to communicate using CDMA2000 (1xRTT / 1xEV-DO / HRPD / eHRPD) or LTE using a single shared radio component and / or using GSM or LTE using a single shared radio component. The shared radio can be coupled to a single antenna or can be coupled to multiple antennas (e.g., for MIMO) for performing wireless communication. Generally, the radio components can include any combination of a baseband processor, analog radio frequency (RF) signal processing circuitry (e.g., including filters, mixers, oscillators, amplifiers, etc.) or digital processing circuitry (e.g., for digital modulation and other digital processing). Similarly, the radio components can implement one or more receive chains and transmit chains using the aforementioned hardware. For example, the UE 106 can share one or more parts of a receive chain and / or a transmit chain among multiple wireless communication technologies such as those discussed above.

[0062] In some embodiments, the UE 106 may include separate transmit chains and / or receive chains (e.g., including separate antennas and other radio components) for each wireless communication protocol it is configured to communicate with. As another possibility, the UE 106 may include one or more radio components shared among multiple wireless communication protocols, and one or more radio components uniquely used by a single wireless communication protocol. For example, the UE 106 may include shared radio components for communicating using either LTE or 5G NR (alternatively, in various possibilities, either LTE or 1xRTT, or either LTE or GSM), and separate radio components for communicating using each of Wi-Fi and Bluetooth. Other configurations are possible.

[0063] Figure 3 FIG. shows an exemplary simplified block diagram of a communication device 106 according to some embodiments. Note that Figure 3 The block diagram of the communication device is only one example of a possible communication device. According to embodiments, in addition to other devices, the communication device 106 may be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop computer, notebook or portable computing device), a tablet computer, and / or a combination of devices. As shown, the communication device 106 may include a set of components 300 configured to perform core functions. For example, the set of components may be implemented as a system-on-chip (SOC), which may include portions for various purposes. Alternatively, the set of components 300 may be implemented as separate components or groups of components for various purposes. This set of components 300 may be (e.g., communicatively; directly or indirectly) coupled to various other circuits of the communication device 106.

[0064] For example, the communication device 106 may include various types of memory (e.g., including NAND flash 310), input / output interfaces such as connector I / F 320 (e.g., for connecting to a computer system; docking station; charging station; input devices such as microphones, cameras, keyboards; output devices such as speakers; etc.), a display 360 that may be integrated with or external to the communication device 106, and wireless communication circuitry 330 (e.g., for LTE, LTE-A, NR, UMTS, GSM, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.). In some embodiments, the communication device 106 may include wired communication circuitry (not shown), such as, for example, a network interface card for Ethernet.

[0065] The wireless communication circuit 330 may be (e.g., communicatively; directly or indirectly) coupled to one or more antennas, such as antenna 335 as shown in the figure. The wireless communication circuit 330 may include a cellular communication circuit and / or a short-range wireless communication circuit, and may include multiple receive chains and / or multiple transmit chains for receiving and / or transmitting multiple spatial streams, such as in a multiple-input multiple-output (MIMO) configuration.

[0066] In some embodiments, as further described below, the cellular communication circuit 330 may include one or more receive chains for multiple RATs (including and / or coupled to (e.g., communicatively; directly or indirectly) dedicated processors and / or radio components (e.g., a first receive chain for LTE and a second receive chain for 5G NR). Additionally, in some embodiments, the cellular communication circuit 330 may include a single transmit chain that can switch between radio components dedicated to a particular RAT. For example, a first radio component may be dedicated to a first RAT (e.g., LTE) and may communicate with a dedicated receive chain and a transmit chain shared with a second radio component. The second radio component may be dedicated to a second RAT (e.g., 5G NR) and may communicate with a dedicated receive chain and the shared transmit chain. In some embodiments, the second RAT may operate at millimeter-wave frequencies. Since the operating frequency of millimeter-wave systems is higher than the typical frequency in LTE systems, signals in the millimeter-wave frequency range are severely attenuated due to environmental factors. To help address this attenuation issue, millimeter-wave systems typically utilize beamforming and include more antennas compared to LTE systems. These antennas may be organized into antenna arrays or panels composed of individual antenna elements. These antenna arrays may be coupled to radio links.

[0067] The communication device 106 may also include one or more user interface elements and / or be configured to work with one or more user interface elements. The user interface elements may include various elements such as a display 360 (which may be a touchscreen display), a keyboard (which may be a discrete keyboard or may be implemented as part of a touchscreen display), a mouse, a microphone and / or a speaker, one or more cameras, one or more buttons, and / or any of various other elements capable of providing information to the user and / or receiving or interpreting user input.

[0068] The communication device 106 may also include one or more smart cards 345 having SIM (Subscriber Identity Module) functionality, such as one or more UICC cards (one or more Universal Integrated Circuit Cards) 345.

[0069] As shown in the figure, the SOC 300 may include a processor 302 and a display circuit 304. The processor may execute program instructions for the communication device 106, and the display circuit may perform graphics processing and provide a display signal to the display 360. One or more processors 302 may also be coupled to a memory management unit (MMU) 340 (the MMU may be configured to receive addresses from one or more processors 302 and convert those addresses into locations in a memory (e.g., memory 306, read-only memory (ROM) 350, NAND flash memory 310)), and / or coupled to other circuits or devices (such as display circuit 304, wireless communication circuit 330, connector I / F 320, and / or display 360). The MMU 340 may be configured to perform memory protection and page table translation or setup. In some embodiments, the MMU 340 may be included as part of the processor 302.

[0070] As described above, the communication device 106 may be configured to communicate using wireless and / or wired communication circuits. As described herein, the communication device 106 may include hardware and software components for implementing any of the various features and technologies described herein. For example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium), the processor 302 of the communication device 106 may be configured to implement some or all of the features described in the present invention. Alternatively (or in addition), the processor 302 may be configured as a programmable hardware element, such as an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit). Alternatively (or in addition), in combination with one or more of the other components 300, 304, 306, 310, 320, 330, 340, 345, 350, 360, the processor 302 of the communication device 106 may be configured to implement some or all of the features described herein.

[0071] In addition, as described in the present invention, the processor 302 may include one or more processing elements. Thus, the processor 302 may include one or more integrated circuits (ICs) configured to perform the functions of the processor 302. In addition, each integrated circuit may include circuits (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of the processor 302.

[0072] In addition, as described herein, the wireless communication circuit 330 may include one or more processing elements. In other words, one or more processing elements may be included in the wireless communication circuit 330. Thus, the wireless communication circuit 330 may include one or more integrated circuits (ICs) configured to perform the functions of the wireless communication circuit 330. In addition, each integrated circuit may include circuits (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of the wireless communication circuit 330.

[0073] Figure 4 Exemplary block diagram of base station 102 according to some embodiments is shown. Note that Figure 4 the base station is only one example of possible base stations. As shown, base station 102 may include a processor 404 that can execute program instructions for base station 102. The processor 404 may also be coupled to a memory management unit (MMU) 440 or other circuits or devices, and the MMU may be configured to receive addresses from the processor 404 and translate these addresses into locations in a memory (e.g., memory 460 and read-only memory (ROM) 450).

[0074] Base station 102 may include at least one network port 470. The network port 470 may be configured to couple to a telephone network and provide access to a plurality of devices such as UE device 106 to the telephone network as described above in Figure 1 and Figure 2 .

[0075] The network port 470 (or an additional network port) may also be configured or alternatively configured to couple to a cellular network, such as a core network of a cellular service provider. The core network may provide mobility-related services and / or other services to a plurality of devices such as UE device 106. In some cases, the network port 470 may be coupled to the telephone network via the core network, and / or the core network may provide the telephone network (e.g., in other UE devices served by the cellular service provider).

[0076] In some embodiments, base station 102 may be a next-generation base station, e.g., a 5G New Radio (5G NR) base station or a "gNB". In such embodiments, base station 102 may be connected to a legacy Evolved Packet Core (EPC) network and / or connected to an NR Core (NRC) / 5G Core (5GC) network. Additionally, base station 102 may be considered a 5G NR cell and may include one or more Transmission and Reception Points (TRPs). Additionally, a UE capable of operating according to 5G NR may be connected to one or more TRPs within one or more gNBs.

[0077] Base station 102 may include at least one antenna 434 and possibly a plurality of antennas. The at least one antenna 434 may be configured to act as a wireless transceiver and may be further configured to communicate with UE device 106 via radio component 430. The antenna 434 communicates with the radio component 430 via communication link 432. The communication link 432 may be a receive link, a transmit link, or both. The radio component 430 may be configured to communicate via various wireless communication standards, including but not limited to 5G NR, LTE, LTE-A, GSM, UMTS, CDMA2000, Wi-Fi, etc.

[0078] Base station 102 may be configured to perform wireless communication using multiple wireless communication standards. In some cases, base station 102 may include multiple radios that enable base station 102 to communicate according to multiple wireless communication technologies. For example, as a possibility, base station 102 may include an LTE radio component for performing communication according to LTE and a 5G NR radio component for performing communication according to 5G NR. In this case, base station 102 may be capable of operating as both an LTE base station and a 5G NR base station. When base station 102 supports millimeter waves, the 5G NR radio component may be coupled to one or more millimeter wave antenna arrays or panels. As another possibility, base station 102 may include a multi-mode radio component capable of performing communication according to any one of multiple wireless communication technologies (e.g., 5G NR and LTE, 5G NR and Wi-Fi, LTE and Wi-Fi, LTE and UMTS, LTE and CDMA2000, UMTS and GSM, etc.).

[0079] As further described subsequently herein, BS 102 may include hardware and software components for implementing or supporting the specific implementations of the features described herein. The processor 404 of base station 102 may be configured to implement or support the implementation of part or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, processor 404 may be configured as a programmable hardware element such as an FPGA (Field Programmable Gate Array), or as an ASIC (Application Specific Integrated Circuit), or a combination thereof. Alternatively (or in addition), in combination with one or more of other components 430, component 432, component 434, component 440, component 450, component 460, component 470, the processor 404 of base station 102 may be configured to implement or support the implementation of part or all of the features described herein.

[0080] Furthermore, as described in the present invention, processor 404 may include one or more processing elements. Thus, processor 404 may include one or more integrated circuits (ICs) configured to perform the functions of processor 404. In addition, each integrated circuit may include circuits (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of processor 404.

[0081] Furthermore, as described in the present invention, radio component 430 may include one or more processing elements. Thus, radio component 430 may include one or more integrated circuits (ICs) configured to perform the functions of radio component 430. In addition, each integrated circuit may include circuits (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of radio component 430.

[0082] Figure 5 An exemplary simplified block diagram of a cellular communication circuit according to some embodiments is shown. Note that Figure 5 the block diagram of the cellular communication circuit is merely an example of a possible cellular communication circuit; other circuits, such as a circuit including or coupled to sufficient antennas for different RATs to perform uplink activities using independent antennas, or a circuit including or coupled to fewer antennas, such as a circuit that can be shared among multiple RATs, are also possible. According to some embodiments, the cellular communication circuit 330 may be included in a communication device such as the communication device 106 described above. As described above, in addition to other devices, the communication device 106 may be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop computer, notebook or portable computing device), a tablet computer, and / or a combination of devices.

[0083] The cellular communication circuit 330 may be (e.g., communicatively; directly or indirectly) coupled to one or more antennas, such as antennas 335a-b and 336 shown in the figure. In some embodiments, the cellular communication circuit 330 may include dedicated receive chains for multiple RATs (including and / or coupled to (e.g., communicatively; directly or indirectly) dedicated processors and / or radio components (e.g., a first receive chain for LTE and a second receive chain for 5G NR). For example, as Figure 5 shown, the cellular communication circuit 330 may include a first modem 510 and a second modem 520. The first modem 510 may be configured for communication according to a first RAT (e.g., such as LTE or LTE-A), and the second modem 520 may be configured for communication according to a second RAT (e.g., such as 5G NR).

[0084] As shown in the figure, the first modem 510 may include one or more processors 512 and a memory 516 communicatively coupled to the processors 512. The modem 510 may communicate with a radio frequency (RF) front end 530. The RF front end 530 may include circuitry for transmitting and receiving radio signals. For example, the RF front end 530 may include a receive circuit (RX) 532 and a transmit circuit (TX) 534. In some embodiments, the receive circuit 532 may communicate with a downlink (DL) front end 550, which may include circuitry for receiving radio signals via antenna 335a.

[0085] Similarly, the second modem 520 may include one or more processors 522 and a memory 526 communicatively coupled to the processors 522. The modem 520 may communicate with an RF front end 540. The RF front end 540 may include circuitry for transmitting and receiving radio signals. For example, the RF front end 540 may include a receive circuit 542 and a transmit circuit 544. In some embodiments, the receive circuit 542 may communicate with a DL front end 560, which may include circuitry for receiving radio signals via an antenna 335b.

[0086] In some embodiments, a switch 570 may couple the transmit circuit 534 to an uplink (UL) front end 572. Additionally, the switch 570 may couple the transmit circuit 544 to the UL front end 572. The UL front end 572 may include circuitry for transmitting radio signals via an antenna 336. Thus, when the cellular communication circuit 330 receives an instruction to transmit according to a first RAT (e.g., supported via the first modem 510), the switch 570 may be switched to a first state that allows the first modem 510 to transmit signals according to the first RAT (e.g., via a transmit chain including the transmit circuit 534 and the UL front end 572). Similarly, when the cellular communication circuit 330 receives an instruction to transmit according to a second RAT (e.g., supported via the second modem 520), the switch 570 may be switched to a second state that allows the second modem 520 to transmit signals according to the second RAT (e.g., via a transmit chain including the transmit circuit 544 and the UL front end 572).

[0087] As described herein, the first modem 510 and / or the second modem 520 may include hardware and software components for implementing any of the various features and techniques described herein. For example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium), the processors 512, 522 may be configured to implement some or all of the features described herein. Alternatively (or in addition), the processors 512, 522 may be configured as programmable hardware elements, such as an FPGA (field programmable gate array) or as an ASIC (application specific integrated circuit). Alternatively (or in addition), in combination with one or more of the other components 530, 532, 534, 540, 542, 544, 550, 570, 572, 335, and 336, the processors 512, 522 may be configured to implement some or all of the features described herein.

[0088] In addition, as described herein, processors 512, 522 may include one or more processing elements. Accordingly, processors 512, 522 may include one or more integrated circuits (ICs) configured to perform the functions of processors 512, 522. In addition, each integrated circuit may include circuits (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of processors 512, 522.

[0089] In some embodiments, the cellular communication circuit 330 may include only one transmit / receive chain. For example, the cellular communication circuit 330 may not include the modem 520, the RF front end 540, the DL front end 560, and / or the antenna 335b. As another example, the cellular communication circuit 330 may not include the modem 510, the RF front end 530, the DL front end 550, and / or the antenna 335a. In some embodiments, the cellular communication circuit 330 may also not include the switch 570, and the RF front end 530 or the RF front end 540 may communicate with the UL front end 572, e.g., directly.

[0090] Figure 6 An exemplary block diagram of a network element 600 is shown in accordance with some embodiments. According to some embodiments, the network element 600 may implement one or more logical functions / entities of a cellular core network, such as a mobility management entity (MME), a serving gateway (S-GW), an access and management function (AMF), a session management function (SMF), a network slice quota management (NSQM) function, etc. It should be noted that Figure 6 the network element 600 shown is only one example of a possible network element 600. As shown, the core network element 600 may include one or more processors 604 that may execute program instructions of the core network element 600. The processor 604 may also be coupled to a memory management unit (MMU) 640 (which may be configured to receive addresses from the processor 604 and translate these addresses into locations in a memory, e.g., the memory 660 and the read-only memory (ROM) 650), or coupled to other circuits or devices.

[0091] The network element 600 may include at least one network port 670. The network port 670 may be configured to couple to one or more base stations and / or other cellular network entities and / or devices. The network element 600 may communicate with base stations (e.g., eNB / gNB) and / or other network entities / devices by means of any of a variety of communication protocols and / or interfaces.

[0092] As further described hereinbelow, network element 600 may include hardware and software components for implementing or supporting embodiments of the features described herein. The processor 604 of the core network element 600 may be configured to implement or support embodiments of some or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, the processor 604 may be configured as a programmable hardware element such as an FPGA (Field Programmable Gate Array) or configured as an ASIC (Application Specific Integrated Circuit) or a combination thereof.

[0093] Turning now to Figure 7 , various PTRS configurations 700 are shown. In a first exemplary PTRS configuration 702, PTRS is transmitted on each OFDM symbol of the allocated PDSCH in a particular physical resource block (PRB). In a second exemplary PTRS configuration 704, PTRS is transmitted on every second OFDM symbol of the allocated PDSCH, and in a third exemplary PTRS configuration 706, PTRS is transmitted on every fourth OFDM symbol.

[0094] The exemplary PTRS configurations 702, 704, and 706 vary in the time domain, while the PTRS configurations 708 and 710 show exemplary PTRS configurations that vary in the frequency domain. In the exemplary PTRS configuration 708, every second PRB includes PTRS, and in the exemplary PTRS configuration 710, every fourth PRB includes PTRS. There may be a trade-off between phase tracking accuracy and signaling overhead. If the density of PTRS is relatively high in time or frequency, e.g., in the PTRS configuration 702, the phase tracking accuracy is relatively high, and the CPE can be better compensated to achieve higher performance. However, the higher the PTRS density, the greater the signaling overhead, which results in lower spectral efficiency and / or effective transmission rate.

[0095] In some cases, the power for transmitting PTRS can achieve improved performance of PTRS against PN. In some cases, the PTRS transmission power can be enhanced by borrowing power from another MIMO layer relative to the PDSCH / PUSCH transmission, such as the power for discontinuous transmission (DTX) on other antenna ports (by truncating other layers and using the power allocated for other layers to be used for PTRS transmission). Borrowing power from other MIMO layers is effective if the ports share a power amplifier, such as when using digital beamforming. However, at higher frequencies, such as frequencies above about 45 GHz, analog beamforming can be used. In the case of using analog beamforming, each layer can use a separate power amplifier, which limits the ability to borrow power across layers.

[0096] Turning now to Figure 8, which shows an additional exemplary PTRS configuration according to aspects of the present disclosure. Here, the PTRS configuration 800 shows that the PTRS transmitted on a single port has no power enhancement on a set of frequencies. As shown, the PTRS is transmitted in combination with the PDSCH or PUSCH, where the PDSCH / PUSCH is transmitted at a frequency different from that of the PTRS. In cases where the ability to borrow power for transmitting the PTRS is limited or unavailable, power can instead be borrowed from resource elements for other frequencies.

[0097] As an example, in the PTRS configuration 820, power is borrowed from a part of the PDSCH / PUSCH frequency, and this power is used to enhance the transmission power of the PTRS at the frequency allocated for the PTRS. Rate matching or puncturing can be performed around a part of the borrowed power of the PDSCH / PUSCH. For rate matching, the transmission rate can be adjusted to effectively squeeze the information corresponding to the frequency from which the power is borrowed into the remaining frequencies. For puncturing, the information corresponding to the frequency from which the power is borrowed is simply discarded. This information can be retransmitted later.

[0098] In some cases, multiple PTRSs can be transmitted on multiple ports, as shown in the PTRS configuration 840. In the PTRS configuration 840, when the PTRS is transmitted on the first port (i.e., port 1), there are corresponding blank resource elements (REs) on another port (i.e., port 2). In such cases, power can be borrowed from the pre-provided power for the blank REs on the second port, as shown in the PTRS configuration 860. In single-port and multi-port enhanced PTRS configurations, signaling can be used to indicate the enhanced PTRS. For example, a wireless node (such as a gNB) can indicate the type of power enhancement, such as frequency-based enhancement or layer-based enhancement. As another example, a wireless device can indicate to the wireless node a preferred or supported type of power enhancement, such as part of the capability signaling.

[0099] In some cases, the power spectral density (PSD) for enhanced PTRS can be applied. For example, an unlicensed band may be subject to a maximum average equivalent isotropic radiated power (EIRP) density. In some cases, the PSD can be detected and measured by a wireless device or a wireless node. When the PSD is observed, the PTRS may or may not be enhanced based on the observed PSD. In some cases, such as using dynamic signaling, the wireless device or the wireless node can autonomously switch between enhanced PTRS and non-enhanced PTRS. For example, on the downlink side, the wireless node can indicate to the wireless device via downlink control information (DCI) / medium access control (MAC) control element (MAC-CE) signaling for the physical downlink shared channel (PDSCH) whether enhanced PTRS or non-enhanced PTRS is to be used. Similarly, on the uplink side, the wireless node can indicate to the wireless device via DCI / MAC-CE signaling for the physical uplink shared channel (PUSCH), for example, whether enhanced PTRS or non-enhanced PTRS is to be used. In other cases, the wireless node can explicitly configure or signal to the wireless device whether enhanced PTRS or non-enhanced PTRS is to be used. This configuration can be based on an indication of the wireless device's preference and / or supported configuration.

[0100] In some cases, the switching between enhanced and non-enhanced operating modes can be binary or quantized. For example, in some cases, the power of enhanced PTRS can be enabled or disabled based on the observed PSD. In other cases, levels of enhancement can be defined for the PTRS in addition to non-enhancement. These levels can be predefined based on the observed PSD, or the enhancement can be set to a higher or lower enhancement level as needed based on the observed PSD. In other cases, the amount of power by which the PTRS is enhanced can be dynamically adjusted within a possible range of enhancement based on the observed PSD. For example, if the PTRS is a Gold sequence and the measurement of the phase rather than the amplitude of the signal provides sufficient information for PN compensation, it is also possible to adjust the power enhancement applied to the PTRS.

[0101] In some cases, the temporal density of the PTRS can be dynamically adjusted based on the PSD of the PTRS. In such cases, the PSD will remain constant, and the frequency of the PTRS will be constant, but additional PTRS signaling can be added or removed over time. This can help increase the energy (and thus the performance) over time, but it may also result in increased density and lower spectral efficiency.

[0102] In some cases, the frequency density of PTRS signaling can be adjusted to increase the amount of PTRS signaling to help compensate for PN. For example, in the case where the PSD limit of a radio node or radio device is reached and the performance is still relatively low, additional PTRS signaling can be added in the frequency or the PTRS frequency mapping can be changed. If the PN decreases, the added PTRS signaling can be removed. In some cases, the adjustment of the frequency density of PTRS signaling can be performed only after attempting to enhance the power of the PTRS signaling (e.g., when the PSD limit is reached). However, in other cases, the adjustment of the frequency density of PTRS signaling can also be performed independently of power enhancement.

[0103] In the case where the overall signal is modulated using orthogonal frequency division multiplexing (OFDM), the number of resource elements (REs) containing PTRS signals can be increased. In some cases, the additional REs including PTRS can be distributed substantially uniformly across a set of allocated bandwidth or bandwidth part (BWP). In other cases, it may be advantageous to have groups of PTRS. The PTRS groups and the number of PTRS samples per group can vary, for example, from a configuration with one group having X samples per group to a configuration with Y groups having one sample per group.

[0104] Figure 9 An exemplary grouped PTRS configuration in the frequency domain according to aspects of the present disclosure is shown. The first grouped PTRS configuration 900 shows two sets of PTRS for a bandwidth (or BWP), where each set of PTRS includes a single sample, and the single sample occupies one RE. As another example, the second grouped PTRS configuration 910 also includes two PTRS groups for the bandwidth (or BWP), but this time each PTRS group includes two samples in two REs. In a third example, the third grouped PTRS configuration 920 includes one set of PTRS for the bandwidth (or BWP), but the PTRS group includes two samples in two REs.

[0105] In some cases, a group can be defined by the resource block (RB) spacing of PTRS with Z number of samples per RE interval. For example, the fourth grouping PTRS configuration 950 has four RE intervals for PTRS with one sample in one RE allocated per interval, such that for every four REs allocated for PUSCH / PDSCH transmission, the length of the PTRS is one RE. As another example, the fifth PTRS configuration 960 has four RE intervals for PTRS with two samples in two REs allocated per interval, such that for every four REs the length of the PTRS is two REs. As another example, the sixth PTRS configuration 970 has four RE intervals for PTRS with two samples in two REs allocated per interval and a 5-RE offset, such that the first PTRS is transmitted in the fifth RE. In the case of using discrete Fourier transform spread OFDM (DFT-s-OFDM) modulated signals, the number of PTRS groups can be increased similarly, and optionally the number of samples per group can be reduced.

[0106] In some cases, the change in frequency density can be made dynamically, for example, based on the current PSD. In some cases, such a change can be guided by the wireless node. For example, when changing the frequency density of the downlink, the wireless node can signal the frequency and time mapping of the PTRS and the PDSCH for each transmission. As another example, when changing the frequency density of the uplink, the wireless device can, for example, use L1 signaling or MAC-CE to indicate to the wireless node one or more desired PTRS configurations to the wireless node. Signaling via MAC-CE can allow for faster changes in the PTRS configuration but may have more overhead requirements compared to L1 signaling. Then, the wireless node can, for example, modify the PTRS configuration for the next uplink opportunity in the DCI signal. In some cases, the change in frequency density can be made autonomously by the wireless node or by the wireless device. In such cases, the wireless node or the wireless device can, for example, transmit an indication of the time / frequency mapping of the PTRS for each transmission or for a set of PTRS transmissions in the DCI signal or the RRC signal.

[0107] In some cases, a multi-port PTRS can be implemented to increase the amount of PTRS signaling to help compensate for PN. Generally, enabling a multi-port PTRS assumes that physical resources for multi-port transmission are available, including independent oscillators for each beam, each layer, and / or each panel at the radio node and the radio device. A PTRS port can be a logical port for transmitting or receiving PTRS based on a unique combination of antenna, beam, layer, and / or panel. As an example of multi-port PTRS on the downlink, more than one PTRS can be used, and in some cases, the number of PTRS ports can be increased from two to four for both the uplink and the downlink. In the case of configuring multi-port PTRS, the signaling for indicating the PTRS / DMRS association can be used to indicate the association of a PTRS with a specific DMRS port. The number of bits for this signaling can be based on the number of configured PTRS ports. For example, in the case of configuring four PTRS ports, four bits can be used to indicate the association. Similarly, two bits can be used for two PTRS ports and three bits for three PTRS ports. In the case where PTRS is not configured and the transform precoder is enabled or disabled or if the precoding matrix variable maxRank is equal to 1, the number of bits for the PTRS / DMRS association can be zero. In some cases, the association between the PTRS port and the DMRS port can be indicated as shown in the following four tables:

[0108] 1 DMRS port: PTRS-DMRS association for UL.DL PTRS port 0

[0109] Bit 0 Bit 1 DMRS Port 0 0 First Scheduled DMRS Port 0 1 Second Scheduled DMRS Port 1 0 Third Scheduled DMRS Port 1 1 Fourth Scheduled DMRS Port

[0110] Table 1

[0111] 2 ports: PTRS-DMRS association for UL.DL PTRS ports 0, 1

[0112]

[0113]

[0114] Table 2

[0115] 3 ports: PTRS-DMRS association for UL.DL PTRS ports 0, 1, 2

[0116]

[0117] Table 3

[0118] 4 ports: PTRS-DMRS association for UL.DL PTRS ports 0, 1, 2, 3

[0119]

[0120] Table 4

[0121] In some cases, the number of bits indicating the PTRS / DMRS association can be fixed between 0 and 4. In the case of a single PTRS port and a fixed number of bits used, the PTRS port can be mapped to up to 16 DMRS ports, as shown in Table 5 below.

[0122] 1 DMRS port: PTRS-DMRS association for UL.DL PTRS port 0

[0123]

[0124]

[0125] Table 5

[0126] In the case of two PTRS ports mapped to four DMRS ports with a fixed number of bits indicating used, the mapping can use the two most significant bits (MSB) or the two least significant bits (LSB), and can be based on the mapping shown in Table 6 below.

[0127] 2 ports: PTRS-DMRS association for UL.DL PTRS ports 0, 1 with 4-bit signaling

[0128]

[0129] Table 6

[0130] In the case of three PTRS ports, up to two DMRS ports can be mapped per PTRS with a fixed number of bits indicating used by using the three most significant bits (MSB) or the last three MSB. Similarly, in the case of four PTRS ports per PTRS with a mapping to up to two DMRS ports, the mapping can be as shown in Table 4 above.

[0131] In some cases, in a CSI report, a layer indicator (LI) report can be used to indicate to a wireless node a preferred PTRS precoder. If multiple PTRS ports are used, the wireless device can be configured to report multiple LIs to the wireless node. In some cases, multiple LI reports can be included in a single CSI report. In other cases, a single LI report can be configured to indicate a preferred PR-RS precoder for multiple PTRS ports.

[0132] In some cases, the PTRS configuration may be based on the SCS used. The PTRS configuration may determine the number of RBs for the PTRS and the modulation and coding scheme (MCS). According to aspects of the present disclosure, the PTRS configuration may be determined, at least in part, based on the transmission frequency band. For example, when transmitting between approximately 50 GHz and 71 GHz, a specific PTRS configuration may be used.

[0133] In some cases, an indication may be provided to indicate the frequency band associated with the PTRS configuration. For example, in the case of sharing an SCS for multiple frequency bands, this indication may be used. In other cases, a new PTRS configuration may be defined for a frequency band having an SCS configuration different from other frequency bands. In such cases, the SCS configuration will indicate the frequency band. In other cases, a modifiable table (e.g., configuration) may be defined based on a component carrier (CC) or a BWP such that a specific combination of the CC and the BWP implies a PTRS configuration. In other cases, multiple configurations may be defined for a given SCS and / or frequency band. In such cases, the specific PTRS configuration for uplink or downlink may be determined based on multiple factors such as the type of traffic, channel priority, or signaling in the slot format indicator (SFI). As an example, for a specific SCS / frequency band, different PTRS configurations may be based on whether the type of communication to be carried is URLLC communication or eMBB communication. By tailoring the PTRS configuration to the type of communication, the PTRS can be configured to provide, for example, higher reliability for URLLC communication while sacrificing some high-bandwidth capabilities, and vice versa for eMBB communication. As another example, different PTRS configurations may be based on the PUSCH priority or the priority of the HARQ-ACK associated with the PDSCH transmission. In another example, the PTRS configuration may be slot-specific and the configuration may be based on the parameters signaled in the SFI at the start of the slot.

[0134] In some cases, the PTRS may not appear in every OFDM symbol, and the CPE estimate for an OFDM symbol without a PTRS can be interpolated based on the available PTRS estimates in the time domain. This interpolation may increase the detection latency and the buffering requirements for the received transmission. Additionally, at higher frequencies, such as above approximately 50 GHz, the beam is typically quite narrow and locked to a specific wireless device. Additionally, at higher frequencies, the bandwidth is relatively wide. In such cases, the transmission may be very short, typically only one or two symbols long. Interpolating the PTRS in such systems can be challenging. In some cases where the transmission is only one symbol long, the PTRS can be omitted at the DMRS that will be transmitted in one symbol. In cases where the transmission is longer than one symbol, the time density of the PTRS can be set to 1. By setting the time density of the PTRS to 1, the PTRS can be sent for each symbol. In some cases, if the transmission is two symbols and if the number of symbols is greater than 2, the time density of the PTRS can be set to 1 and then the configured time density can be used. In other cases where the number of symbols is greater than 1, the configured time density can be used and the PTRS can always be transmitted on the last symbol. Transmitting the PTRS on the last symbol avoids possible issues from interpolating across multiple symbols at the signal edge.

[0135] Figure 10 is a flowchart illustrating an exemplary technique for phase noise compensation 1000 in a wireless system. At block 1010, one or more resource elements are selected. At block 1020, the transmission of the phase-tracking reference signal (PTRS) scheduled in the selected one or more resource elements is enhanced using the power allocated for the one or more resource elements at other frequencies.

[0136] Figure 11is a flowchart showing an exemplary technique for phase noise compensation 1020 in a wireless system. At block 1022, PTRS is transmitted on one or more PTRS ports. A PTRS port can be understood as a logical port defined based on a combination of an antenna, an antenna element, a beam, a layer, etc. In some cases, PTRS can be transmitted on one PTRS port, and in other cases, PTRS can be transmitted on multiple PTRS ports. Power can be borrowed from PUSCH / PDSCH resource elements in either case. At block 1024, one or more selected resource elements are scheduled for transmission of a physical shared channel, and the power allocated for transmitting the physical shared channel in the one or more selected resource elements is used to transmit PTRS in the one or more selected resource elements. As an example, power for resource elements initially allocated for PUSCH or PDSCH transmission can be borrowed, and this power can be used to transmit PTRS. In some cases, at block 1026, rate matching can be performed on the physical shared channel around the one or more selected resource elements. For example, rate matching attempts to adjust the transmission rate of the remainder of the PUSCH / PDSCH (including the part from which power is borrowed) to fit the original PUSCH / PDSCH message. In some cases, at block 1028, the physical shared channel is punctured for the one or more selected resource elements to transmit PTRS. Note that the dashed lines indicate optional steps or paths that can be performed.

[0137] Figure 12 is a flowchart showing an exemplary technique for phase noise compensation 1200 in a wireless system. At block 1202, enhancing the transmission of PTRS using the power allocated for one or more resource elements can be based on an indication from a wireless node. In some cases, the indication can be a configuration message. At block 1204, the amount of power used to enhance the transmission of PTRS can be adjusted based on power density measurement or estimation. This measurement or estimation can be performed by a wireless device or a wireless node. If the measurement is performed by the wireless node, the indication to use power enhancement can include an indication of how much power to use. In some cases, the amount of enhancement to be applied can be binary (e.g., on or off) or quantized (e.g., based on defined power levels). In other cases, the amount of enhancement to be applied can be configured within a range. In some cases, the number of resource elements (REs) used to enhance PTRS can be selected based on power signal density measurement or estimation.

[0138] At block 1206, a frequency band can be determined based on the transmitted frequency band, where the frequency band is based on at least one of SCS, CC, or BWP. At block 1208, a configuration for PTRS can be determined based on the determined frequency band. At block 1210, one or more resource elements can be selected based on the determined PTRS configuration. At block 1212, a PTRS configuration can be determined based on one of the parameters in the transmitted traffic type, channel priority, or slot format indicator. At block 1214, one or more resource elements can be selected based on the determined PTRS configuration.

[0139] Figure 13 is a flowchart showing an exemplary technique 1300 for phase noise compensation in a wireless system according to aspects of the present disclosure. At block 1302, it is determined that additional phase tracking reference signals (PTRS) are needed. For example, this determination can be made if the performance is low due to PN and the transmission is at or near the PSD limit. In other cases, the determination can be based on the PTRS configuration. The PTRS configuration can be determined based on a parameter in the transmitted frequency band, transmitted traffic type, channel priority, or slot format indicator.

[0140] At block 1304, one or more resource elements allocated for the shared control channel are selected, where the selected resource elements are distributed across the bandwidth. In some cases, the selected resource elements can be relatively evenly distributed across the bandwidth or BWP. In other cases, the selected resource elements can be unevenly distributed across the bandwidth or BWP. As an example, the selected resource elements can be grouped. The grouping can be based on the number of groups and the number of samples or the number of samples per resource block interval per bandwidth or BWP.

[0141] At block 1306, the PTRS is transmitted in the selected one or more resource elements using the frequency allocated for the selected one or more resource elements. At block 1308, a mapping of the PTRS transmission can be received. For example, a wireless device can receive the mapping transmitted from a wireless node. Alternatively, the wireless device can transmit the mapping for the wireless node to receive. This mapping can be based on PSD measurement or estimation. At block 1310, it can be determined that additional PTRS is needed based on the mapping. Additional PTRS can be received or transmitted based on the mapping.

[0142] Figure 14is a flowchart illustrating an exemplary technique for phase noise compensation 1400 in a wireless system according to aspects of the present disclosure. At block 1402, it is determined that an additional phase tracking reference signal (PTRS) is needed. For example, this determination can be made if the performance is low due to PN and the transmission is already at or near the PSD limit. In other cases, the determination can be based on the PTRS configuration. The PTRS configuration can be determined based on parameters such as the transmission frequency band, the type of communication traffic being transmitted, the channel priority, or the slot format indicator. At block 1404, the additional PTRS can be transmitted on multiple PTRS ports, and the number of bits of the PTRS precoder is based on the number of PTRS ports. In some cases, the number of bits of the PTRS precoder can be selected from 0 to 4. At block 1406, a layer indicator report indicating the preferred PTRS precoder can be transmitted in the channel state information (CSI) report. In some cases, the CSI report can include more than one layer.

[0143] Figure 15 is a flowchart illustrating an exemplary technique for phase noise compensation 1500 in a wireless system according to aspects of the present disclosure. At block 1502, the number of symbols required for transmission can be determined. At block 1504, when the determined number of symbols is one, it can be determined not to transmit the PTRS signal.

[0144] Figure 16 is a flowchart illustrating an exemplary technique for phase noise compensation 1600 in a wireless system according to aspects of the present disclosure. At block 1602, the number of symbols required for transmission can be determined. At block 1604, when the determined number of symbols is greater than one, the time density of the phase tracking reference signal (PTRS) is set to one. At block 1606, when the determined number of symbols is greater than two, the configured time density is used.

[0145] Figure 17 is a flowchart illustrating an exemplary technique for phase noise compensation 1700 in a wireless system according to aspects of the present disclosure. At block 1702, the number of symbols required for transmission can be determined. At block 1704, when the determined number of symbols is greater than one, the phase tracking reference signal is transmitted on the last symbol.

[0146] Embodiments

[0147] In the following sections, additional exemplary implementations are provided.

[0148] According to Example 1, a method for phase noise compensation in a wireless system is disclosed, including: selecting one or more resource elements; and using the power allocated for the one or more resource elements at other frequencies to enhance the transmission of phase tracking reference signals (PTRS) scheduled in the selected one or more resource elements.

[0149] Example 2 includes the subject matter according to Example 1, wherein the PTRS is transmitted on a single PTRS port, wherein the selected one or more resource elements are scheduled for transmitting a physical shared channel, and wherein the power allocated for transmitting the physical shared channel in the selected one or more resource elements is used to transmit the PTRS in the selected one or more resource elements.

[0150] Example 3 includes the subject matter according to Example 2, further including: rate matching the physical shared channel around the selected one or more resource elements.

[0151] Example 4 includes the subject matter according to Example 3, further including: truncating the physical shared channel transmission for the selected one or more resource elements.

[0152] Example 5 includes the subject matter according to Example 1, wherein the PTRS is transmitted on multiple PTRS ports, and wherein the selected one or more resource elements are blank resource elements.

[0153] Example 6 includes the subject matter according to Example 1, wherein using the power allocated for one or more resource elements to enhance the transmission of the PTRS is based on an indication from a wireless node.

[0154] Example 7 includes the subject matter according to Example 6, wherein the indication from the wireless node includes a configuration message.

[0155] Example 8 includes the subject matter according to Example 6, wherein the amount of power used to enhance the transmission of the PTRS is adjusted based on the power signal density of the PTRS.

[0156] Example 9 includes the subject matter according to Example 8, wherein the amount of power used to enhance the transmission of the PTRS is adjusted to enhance the transmission or adjusted not to enhance the transmission.

[0157] Example 10 includes the subject matter according to Example 6, wherein the number of resource elements is selected based on the power signal density of the PTRS.

[0158] Embodiment 11 includes the subject matter according to Embodiment 1, and further includes: determining a transmission frequency band, wherein the frequency band is determined based on at least one of a subcarrier spacing, a component carrier, or a bandwidth part; determining a PT-RS PTRS configuration based on the determined frequency band; and selecting one or more resource elements based on the determined PT-RS PTRS configuration.

[0159] Embodiment 12 includes the subject matter according to Embodiment 1, and further includes: determining a PT-RS PTRS configuration based on one of parameters such as a type of transmitted communication traffic, a channel priority, or a time slot format indicator; and selecting one or more resource elements based on the determined PT-RS PTRS configuration.

[0160] Embodiment 13 is a method for phase noise compensation in a wireless system, including: determining a need for additional phase tracking reference signals (PTRS); selecting one or more resource elements allocated for a shared control channel, wherein the selected resource elements are distributed across a bandwidth; and transmitting the PTRS in the selected one or more resource elements using a frequency allocated for the selected one or more resource elements.

[0161] Embodiment 14 includes the subject matter according to Embodiment 13, wherein the selected resource elements are unevenly distributed across the bandwidth.

[0162] Embodiment 15 includes the subject matter according to Embodiment 13, and further includes: determining one or more sets of PTRS transmissions, wherein the set is based on one of the following: a number of sets for a bandwidth and a number of samples for each set in the number of sets or a number of samples for an interval of resource blocks per bandwidth.

[0163] Embodiment 16 includes the subject matter according to Embodiment 13, and further includes: receiving a mapping for PTRS transmission based on a power signal density; and determining a need for additional PTRS based on the received mapping.

[0164] Embodiment 17 includes the subject matter according to Embodiment 13, and further includes: receiving a mapping for PTRS transmission based on a power signal density; and receiving additional PTRS based on the received mapping.

[0165] Embodiment 18 includes the subject matter according to Embodiment 13, and further includes: transmitting an indication of a PTRS configuration to a wireless node, determining the PTRS configuration based on a power signal density; and transmitting the PTRS based on the indication.

[0166] Embodiment 19 includes the subject matter according to Embodiment 13, and further includes: receiving an indication of a PTRS configuration from a wireless node, determining the PTRS configuration based on a power signal density; and receiving the PTRS based on the received mapping.

[0167] Embodiment 20 is a method for phase noise compensation in a wireless system, including: determining that additional phase tracking reference signals (PTRS) are needed; and transmitting the additional PTRS on multiple PTRS ports, and wherein the number of bits of the PTRS precoder is based on the number of PTRS ports.

[0168] Embodiment 21 includes the subject matter according to Embodiment 20, wherein the PTRS is transmitted on multiple PTRS ports, and wherein the number of bits of the PTRS precoder is selected from 0 to 4.

[0169] Embodiment 22 includes the subject matter according to Embodiment 20, wherein the PTRS is transmitted on multiple PTRS ports, and further includes: transmitting a layer indicator report indicating a preferred PT-RS PTRS precoder in a channel state information (CSI) report.

[0170] Embodiment 23 includes the subject matter according to Embodiment 22, wherein the CSI report indicates more than one layer.

[0171] Embodiment 24 is a method for phase noise compensation in a wireless system, including: determining the number of symbols required for transmission; when the determined number of symbols is one, determining not to transmit a phase tracking reference signal (PTRS).

[0172] Embodiment 25 is a method for phase noise compensation in a wireless system, including: determining the number of symbols required for transmission; when the determined number of symbols is greater than one, setting the time density of the phase tracking reference signal (PTRS) to one.

[0173] Embodiment 26 includes the subject matter according to Embodiment 25, and further includes: when the determined number of symbols is greater than two, using a configured time density.

[0174] Embodiment 27 is a method for phase noise compensation in a wireless system, including: determining the number of symbols required for transmission; when the determined number of symbols is greater than one, transmitting a phase tracking reference signal (PTRS) on the last symbol.

[0175] Embodiment 28 includes a method that includes any action or combination of actions substantially described herein in the detailed description.

[0176] Embodiment 29 includes a method that is substantially described herein with reference to each drawing or any combination of the drawings included herein or with reference to each paragraph or any combination of paragraphs in the detailed description.

[0177] Example 30 includes a wireless device configured to perform any action or combination of actions substantially described herein in the specific implementations included in the wireless device.

[0178] Example 31 includes a wireless station configured to perform any action or combination of actions substantially described herein in the specific implementations included in the wireless station.

[0179] Example 32 includes a non - volatile computer - readable medium storing instructions that, when executed, cause any action or combination of actions substantially described herein in the specific implementations to be performed.

[0180] Example 33 includes an integrated circuit configured to perform any action or combination of actions substantially described herein in the specific implementations.

[0181] Another exemplary implementation may include a method that includes: the device performing any or all parts of the foregoing examples.

[0182] Yet another exemplary implementation may include a non - transitory computer - accessible memory medium that includes program instructions that, when executed at the device, cause the device to implement any or all parts of any one of the foregoing examples.

[0183] Another exemplary implementation may include a computer program that includes instructions for performing any or all parts of any one of the foregoing examples.

[0184] Yet another exemplary implementation may include a device that includes means for performing any or all elements of any one of the foregoing examples.

[0185] Another exemplary implementation may include a device that includes a processor configured to cause the device to perform any or all elements of any one of the foregoing examples.

[0186] It is well - known that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of inadvertent or unauthorized access or use, and the nature of authorized use should be clearly explained to the user.

[0187] Embodiments of the present disclosure may be implemented in any of a variety of forms. For example, some embodiments may be implemented as a computer-implemented method, a computer-readable memory medium, or a computer system. Other embodiments may be implemented using one or more custom-designed hardware devices such as an ASIC. Other embodiments may be implemented using one or more programmable hardware elements such as an FPGA.

[0188] In some embodiments, a non-transitory computer-readable memory medium may be configured such that it stores program instructions and / or data, where if the program instructions are executed by a computer system, the computer system is caused to perform a method, such as any one of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets.

[0189] In some embodiments, a device (e.g., UE 106, BS 102, network element 600) may be configured to include a processor (or a set of processors) and a memory medium, where the memory medium stores program instructions, where the processor is configured to read and execute the program instructions from the memory medium, where the program instructions are executable to implement any one of the various method embodiments described herein (or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets). The device may be implemented in any of a variety of forms.

[0190] Although the above embodiments have been described in considerable detail, many variations and modifications will become apparent to those skilled in the art once the above disclosure is fully understood. The present disclosure is intended that the following claims be construed to cover all such variations and modifications.

Claims

1. A method for phase noise compensation in a wireless system, comprising: Transmitting a phase tracking reference signal (PTRS) according to a first enhanced configuration; Measuring the power signal density of the PTRS at a first time; Determining a second enhanced configuration for the PTRS based at least in part on the measured power signal density and a maximum average equivalent isotropic radiated power (EIRP) density, wherein determining the second enhanced configuration further comprises: determining the power allocated for one or more resource elements at other frequencies different from the frequency configured for the PTRS for use with the PTRS; And Transmitting the PTRS according to the second enhanced configuration.

2. The method according to claim 1, wherein the one or more resource elements are scheduled for transmitting a physical shared channel, and wherein the power allocated for transmitting the physical shared channel in the one or more resource elements is used to transmit the PTRS in the one or more resource elements.

3. The method according to claim 2 further comprises: Rate matching the physical shared channel around the one or more resource elements.

4. The method according to claim 3 further comprises: Truncating the transmission of the physical shared channel for the one or more resource elements.

5. The method according to claim 1, wherein the PTRS is transmitted on multiple PTRS ports, and wherein the one or more resource elements are blank resource elements.

6. The method according to claim 1, wherein enhancing the transmission of the PTRS using the power allocated for the one or more resource elements is based on an indication from a wireless node.

7. The method according to claim 1, wherein the amount of power for adjusting the transmission of the PTRS is adjusted to enhance the transmission or is adjusted not to enhance the transmission.

8. The method according to claim 6, wherein the number of resource elements is selected based on the power signal density of the PTRS.

9. The method according to claim 1, further comprising: Determining a transmission frequency band, wherein the frequency band is determined based on at least one of a subcarrier spacing, a component carrier, or a bandwidth part; Determining a PTRS configuration based on the determined frequency band; And Selecting the one or more resource elements based on the determined PTRS configuration.

10. The method according to claim 1, further comprising: Determining a PTRS configuration based on one of parameters such as a transmitted traffic type, a channel priority, or a time slot format indicator; And Selecting the one or more resource elements based on the determined PTRS configuration.

11. The method according to claim 1, further comprising: Measuring the power signal density of the PTRS at a second time; And Determining to transmit the PTRS according to the first enhanced configuration based at least in part on the power signal density of the PTRS measured at the second time.

12. A method for phase noise compensation in a wireless system, comprising: Transmitting a phase tracking reference signal (PTRS) according to a first enhanced configuration; Determining that an additional phase tracking reference signal (PTRS) is needed; Determine a second enhanced configuration for the PTRS at least in part based on a power signal density of the PTRS and a maximum average equivalent isotropically radiated power (EIRP) density measured at a first time, wherein determining the second enhanced configuration further includes: determining power allocated for one or more resource elements for the PTRS in other frequency ranges different from a frequency range configured for the PTRS; And Transmit the PTRS according to the second enhanced configuration.

13. The method according to claim 12, wherein the resource elements are unevenly distributed across the bandwidth.

14. The method according to claim 12, further comprising: Determine one or more sets of PTRS transmissions, wherein the set is based on one of the following: The number of sets for the bandwidth and the number of samples for each set in the number of sets, or The number of samples for each interval of resource blocks of the bandwidth.

15. The method according to claim 12, further comprising: Receive a mapping of PTRS transmissions based on the power signal density; And Determine that additional PTRS are needed based on the received mapping.

16. The method according to claim 12, further comprising: Receive a mapping of PTRS transmissions based on the power signal density; And Receive additional PTRS based on the received mapping.

17. The method according to claim 12, further comprising: Transmit an indication of the PTRS configuration, which is determined based on the power signal density, to a wireless node; And Transmit the PTRS based on the indication.

18. The method according to claim 12, further comprising: Receive an indication of the PTRS configuration, which is determined based on the power signal density, from a wireless node; And Receive the PTRS based on the received mapping.

19. The method according to claim 12, further comprising: Measure the power signal density of the PTRS at a second time; And Determine to transmit the PTRS according to the first enhanced configuration at least in part based on the power signal density of the PTRS measured at the second time.

20. A method for phase noise compensation in a wireless system, comprising: Transmit a phase tracking reference signal (PTRS) according to a first enhanced configuration; Determine that one or more additional phase tracking reference signals (PTRS) are needed; Determine a second enhanced configuration for the PTRS at least in part based on a power signal density of the PTRS and a maximum average equivalent isotropically radiated power (EIRP) density measured at a first time, wherein determining the second enhanced configuration further includes: determining power allocated for one or more resource elements for the PTRS in other frequency ranges different from a frequency range configured for the PTRS; And Transmit an additional PTRS among the one or more additional PTRS according to the second enhanced configuration on a plurality of PTRS ports, and wherein the number of bits of the PTRS precoder is based on the number of PTRS ports.

21. The method according to claim 20, wherein the additional PTRS is transmitted on a plurality of PTRS ports, and wherein the number of bits of the PTRS precoder is selected from 0 to 4.

22. The method according to claim 20, wherein the additional PTRS is transmitted on a plurality of PTRS ports, and further comprising: A layer indicator report indicating a preferred PTRS precoder is transmitted in a channel state information (CSI) report.

23. The method according to claim 22, wherein the CSI report indicates more than one layer.

24. The method according to claim 20, further comprising: Measuring a power signal density of the PTRS at a second time; And Determining to transmit the PTRS according to the first enhanced configuration based at least in part on the power signal density of the PTRS measured at the second time.

25. A wireless device, the wireless device comprising a processor configured to perform the method according to any one of claims 1 to 24.

26. A non - volatile computer - readable medium storing instructions which, when executed, cause the performance of the method according to any one of claims 1 to 24.

27. A processor, the processor comprising an integrated circuit configured to perform the method according to any one of claims 1 to 24.

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