WO2022139873A1 - Apparatus and method for phase tracking signals in wireless communication systems - Google Patents

Abstract

Embodiments of an apparatus and method for using phase tracking signals in wireless communication are disclosed. The apparatus modulates traffic resource element with reduced spectral efficiency (TRRSE) resource elements by a first spectral efficiency. The apparatus also transmits the modulated TRRSE resource elements to a receiver using a TRRSE data path. The apparatus also modulates standard resource elements by a second spectral efficiency. The apparatus also transmits the modulated standard resource elements to the receiver using a standard data path. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

Description

APPARATUS AND METHOD FOR PHASE TRACKING SIGNALS IN WIRELESS COMMUNICATION SYSTEMS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63/128,795, filed December 21, 2020, entitled “METHOD FOR PHASE TRACK SIGNAL IN WIRELESS COMMUNICATION SYSTEMS,” which is hereby incorporated by reference in its entirety.

BACKGROUND

[0002] Embodiments of the present disclosure relate to an apparatus and method for using phase tracking signals in wireless communication. Specifically, embodiments relate to an apparatus and method for using phase tracking reference signals in wireless communication in an orthogonal frequency division multiplexing (OFDM) or an orthogonal frequency division multiple access (OFDMA) system.

[0003] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Orthogonal frequency division multiplexing (OFDM) is one of the most widely used and adopted digital multicarrier methods and has been used extensively for cellular communications, such as 4th-generation (4G) Long Term Evolution (LTE) and 5th-generation (5G) New Radio (NR).

SUMMARY

[0004] Embodiments of an apparatus and method for using phase tracking signals in an OFDM or an OFDMA system are disclosed herein.

[0005] In one example, an apparatus including at least one processor and a memory storing instructions is disclosed. The instructions, when executed by the at least one processor, cause the apparatus to modulate traffic resource element with reduced spectral efficiency (TRRSE) resource elements using a first spectral efficiency. The instructions, when executed by the at least one processor, further cause the apparatus to transmit the modulated TRRSE resource elements to a receiver using a TRRSE data path. The instructions, when executed by the at least one processor, further cause the apparatus to modulate standard resource elements using a second spectral efficiency. The instructions, when executed by the at least one processor, further cause the apparatus to transmit the modulated standard resource elements to the receiver using a standard data path. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

[0006] In another example, a method for wireless communication is disclosed. The method includes modulating traffic resource element with reduced spectral efficiency (TRRSE) resource elements using a first spectral efficiency. The method further includes transmitting the modulated TRRSE resource elements to a receiver using a TRRSE data path. The method further includes modulating standard resource elements using a second spectral efficiency. The method further includes transmitting the modulated standard resource elements to the receiver using a standard data path. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

[0007] In another example, a baseband chip is disclosed. The baseband chip includes a traffic resource element with reduced spectral efficiency (TRRSE) modulation circuit. The TRRSE modulation circuit is configured to modulate TRRSE resource elements using a first spectral efficiency. The baseband chip further includes a TRRSE transmission circuit. The TRRSE transmission circuit is configured to transmit the modulated TRRSE resource elements to a receiver using a TRRSE data path. The baseband chip further includes a standard element modulation circuit. The standard element modulation circuit is configured to modulate standard resource elements using a second spectral efficiency. The baseband chip further includes a standard element transmission circuit. The standard element transmission circuit is configured to transmit the modulated standard resource elements to the receiver using a standard data path. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

[0008] In another example, an apparatus for wireless communication including at least one processor and a memory storing instructions is disclosed. The instructions, when executed by the at least one processor, cause the apparatus to receive traffic resource element with reduced spectral efficiency (TRRSE) resource elements, modulated by a transmitter using a first spectral efficiency, from the transmitter using a TRRSE data path. The instructions, when executed by the at least one processor, further cause the apparatus to estimate phase noise information based on the TRRSE resource elements. The instructions, when executed by the at least one processor, further cause the apparatus to receive standard resource elements, modulated by the transmitter using a second spectral efficiency, from the transmitter using a standard data path based on the phase noise information. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

[0009] In another example, a method for wireless communication is disclosed. The method includes receiving traffic resource element with reduced spectral efficiency (TRRSE) resource elements, modulated by a transmitter using a first spectral efficiency, from the transmitter using a TRRSE data path. The method further includes estimating phase noise information based on the TRRSE resource elements. The method further includes receiving standard resource elements, modulated by the transmitter using a second spectral efficiency, from the transmitter using a standard data path based on the phase noise information. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

[0010] In another example, a baseband chip is disclosed. The baseband chip includes a traffic resource element with reduced spectral efficiency (TRRSE) receiving circuit. The TRRSE receiving circuit is configured to receive TRRSE resource elements, modulated by a transmitter using a first spectral efficiency, from the transmitter using a TRRSE data path. The baseband chip further includes a phase noise estimation circuit. The phase noise estimation circuit is configured to estimate phase noise information based on the TRRSE resource elements. The baseband chip further includes a standard resource element receiving circuit. The standard resource element receiving circuit is configured to receive standard resource elements, modulated by the transmitter using a second spectral efficiency, from the transmitter using a standard data path based on the phase noise information. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable a person skilled in the pertinent art to make and use the present disclosure.

[0012] FIG. 1 illustrates a wireless network, according to some embodiments of the present disclosure.

[0013] FIG. 2 illustrates an example of a reference signal (RS) configuration.

[0014] FIG. 3 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure.

[0015] FIG. 4 illustrates a block diagram of another transmission apparatus, according to some embodiments of the present disclosure.

[0016] FIG. 5 illustrates a block diagram of still another transmission apparatus, according to some embodiments of the present disclosure.

[0017] FIG. 6 illustrates a block diagram of yet another transmission apparatus, according to some embodiments of the present disclosure. [0018] FIG. 7 illustrates a block diagram yet another a transmission apparatus, according to some embodiments of the present disclosure.

[0019] FIG. 8 illustrates a block diagram of yet another transmission apparatus, according to some embodiments of the present disclosure.

[0020] FIG. 9 illustrates a block diagram of yet another transmission apparatus, according to some embodiments of the present disclosure.

[0021] FIG. 10 illustrates a block diagram of yet another transmission apparatus, according to some embodiments of the present disclosure.

[0022] FIG. 11 illustrates a block diagram of yet another transmission apparatus, according to some embodiments of the present disclosure.

[0023] FIG. 12 illustrates a block diagram of yet another transmission apparatus, according to some embodiments of the present disclosure.

[0024] FIG. 13 illustrates a block diagram of yet another transmission apparatus, according to some embodiments of the present disclosure.

[0025] FIG. 14 illustrates a block diagram of yet another transmission apparatus, according to some embodiments of the present disclosure.

[0026] FIGS. 15A and 15B illustrate block diagrams of an apparatus including a host chip, a radio frequency (RF) chip, and a baseband chip implementing a wireless communication system, according to some embodiments of the present disclosure.

[0027] FIG. 16 is a sequence diagram for an apparatus for managing phase tracking signals, according to some embodiments of the present disclosure.

[0028] FIGS. 17A-17D illustrate flowcharts of methods for managing phase tracking signals in a transmitter, according to some embodiments of the present disclosure.

[0029] FIG. 18 illustrates a flowchart of a method for managing phase tracking signals in a receiver, according to some embodiments of the present disclosure.

[0030] FIG. 19 is a block diagram of a transmission apparatus for managing phase tracking signals, according to some embodiments of the present disclosure.

[0031] FIG. 20 is a block diagram of a receiving apparatus for managing phase tracking signals, according to some embodiments of the present disclosure.

[0032] FIGS. 21A-21H are diagrams illustrating how PT-RS blocks and TRRSE blocks are organized in various examples.

[0033] FIG. 22 illustrates a block diagram of a communications device, according to some embodiments of the present disclosure.

[0034] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

DETAILED DESCRIPTION

[0035] Although specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the pertinent art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the present disclosure. It will be apparent to a person skilled in the pertinent art that the present disclosure can also be employed in a variety of other applications.

[0036] It is noted that references in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” “some embodiments,” “certain embodiments,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of a person skilled in the pertinent art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0037] In general, terminology may be understood at least in part from usage in context. For example, the term “one or more” as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures, or characteristics in a plural sense. Similarly, terms, such as “a,” “an,” or “the,” again, may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context. In addition, the term “based on” may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.

[0038] Various aspects of wireless communication systems will now be described with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, units, components, circuits, steps, operations, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, firmware, computer software, or any combination thereof. Whether such elements are implemented as hardware, firmware, or software depends upon the particular application and design constraints imposed on the overall system. [0039] The techniques described herein are principally described in the context of the operation of an orthogonal frequency division multiplexing (OFDM) or an orthogonal frequency division multiple access (OFDMA) system. However, to the extent they are relevant, the techniques and ideas described herein may also be used for and in combination with various wireless communication networks, such as code division multiple access (CDMA) system, time division multiple access (TDMA) system, frequency division multiple access (FDMA) system, single-carrier frequency division multiple access (SC-FDMA) system, and other networks. For example, networks may include but are not limited to 4G LTE, and 5G NR cellular networks, as well as WI-FI wireless networks. The terms “network” and “system” are often used interchangeably. The techniques described herein may be used for the wireless networks mentioned above, as well as other wireless networks, though they are particularly adapted to and explained in the context of OFDMA systems.

[0040] Orthogonal frequency-division multiple access (OFDMA) is a multi-user version of the popular orthogonal frequency-division multiplexing (OFDM) digital modulation scheme. Multiple access is achieved in OFDMA by assigning subsets of subcarriers to individual users. This allows simultaneous low-data-rate transmission from several users.

[0041] Phase noise causes significant challenges to a receiver in some bands (for example, mmWave bands). A phase tracking reference signal (PT-RS) is a common way to help a receiver estimate phase noise and compensate for the phase noise. However, a PT-RS acts as an overhead. The PT-RS is an overhead because it does not send information bits but is only a reference signal. The more resources a PT-RS uses, the more resources the PT-RS wastes as overhead.

[0042] As described above, phase noise presents a significant challenge for a receiver in some bands. The present disclosure provides for a resource element in which traffic data is sent through a data path having a lower spectral efficiency value than a scheduled spectral efficiency value to allow the use of such traffic data to track phase noise. The present embodiments may work either without or with a phase tracking reference signal (PT-RS). Embodiments improve spectral efficiency by removing such a phase tracking reference signal entirely or reducing resources otherwise occupied by a phase tracking reference signal. Either way, overhead decreases. Spectral efficiency is defined as the number of bits transmitted in a Hz. There are different methods to achieve higher spectral efficiency, including but not limited to higher modulation and coding scheme (MCS), higher multiple-input and multiple-output (MIMO) rank, etc.

[0043] Thus, a PT-RS is a reference signal that is added in 5G to manage phase noise. The PT-RS is a known pseudo-random sequence initialized based on different known parameters. For example, the resources of the PT-RS in the time domain and in the frequency domain are configured by Base Station (BS) gNode B. A parameter frequencyDensity defines the presence and frequency density of uplink (UL) PT-RS as a function of Scheduled Bandwidth (BW). A parameter timeDensity defines the presence and time density of UL PT-RS as a function of an MCS. However, related parameters may be used in the case of a downlink (DL) PT-RS.

[0044] Thus, a significant aspect of the embodiments is to use traffic resource element (RE) with reduced spectral efficiency (TRRSE) for phase tracking in order to remove PT-RS or reduce densities of PT-RS that would otherwise be required for phase tracking.

[0045] FIG. 1 illustrates a wireless network 100, according to some embodiments of the present disclosure. As shown in FIG. 1, wireless network 100 may include a network of nodes, such as a user equipment (UE) 102, an access node 104, and a core network element 106. User equipment 102 may be any terminal device, such as a mobile phone, a desktop computer, a laptop computer, a tablet, a vehicle computer, a gaming console, a printer, a positioning device, a wearable electronic device, a smart sensor, or any other device capable of receiving, processing, and transmitting information, such as any member of a vehicle to everything (V2X) network, a cluster network, a smart grid node, or an Internet-of-Things (loT) node. It is understood that user equipment 102 is illustrated as a mobile phone simply by way of illustration and not by way of limitation.

[0046] Access node 104 may be a device that communicates with UE 102, such as a wireless access point, a base station (BS), a Node B, an enhanced Node B (eNodeB or eNB), a next-generation NodeB (gNodeB or gNB), a cluster master node, or the like. Access node 104 may have a wired connection to UE 102, a wireless connection to UE 102, or any combination thereof. Access node 104 may be connected to UE 102 by multiple connections, and UE 102 may be connected to other access nodes in addition to access node 104. Access node 104 may also be connected to other UEs. It is understood that access node 104 is illustrated by a radio tower by way of illustration and not by way of limitation.

[0047] Core network element 106 may serve access node 104 and user equipment 102 to provide core network services. Examples of core network element 106 may include a home subscriber server (HSS), a mobility management entity (MME), a serving gateway (SGW), or a packet data network gateway (PGW). These are examples of core network elements of an evolved packet core (EPC) system, which is a core network for the LTE system. Other core network elements may be used in LTE and in other communication systems. In some embodiments, core network element 106 includes an access and mobility management function (AMF) device, a session management function (SMF) device, or a user plane function (UPF) device, of a core network for the NR system. It is understood that core network element 106 is shown as a set of rack-mounted servers by way of illustration and not by way of limitation.

[0048] Core network element 106 may connect with a large network, such as the Internet 108, or another Internet Protocol (IP) network, to communicate packet data over any distance. In this way, data from user equipment 102 may be communicated to other user equipment connected to other access points, including, for example, a computer 110 connected to Internet 108, for example, using a wired connection or a wireless connection, or to a tablet 112 wirelessly connected to Internet 108 via a router 114. Thus, computer 110 and tablet 112 provide additional examples of possible user equipment, and router 114 provides an example of another possible access node.

[0049] A generic example of a rack-mounted server is provided as an illustration of core network element 106. However, there may be multiple elements in the core network including database servers, such as a database 116, and security and authentication servers, such as an authentication server 118. Database 116 may, for example, manage data related to user subscriptions to network services. A home location register (HLR) is an example of a standardized database of subscriber information for a cellular network. Likewise, authentication server 118 may handle authentication of users, sessions, and so on. In the NR system, an authentication server function (AUSF) device may be the specific entity to perform user equipment authentication. In some embodiments, a single server rack may handle multiple such functions, such that the connections between core network element 106, authentication server 118, and database 116, may be local connections within a single rack.

[0050] As described below in greater detail, in some embodiments, wireless communication can be established between any suitable nodes in wireless network 100, such as between UE 102 and access node 104, and between UE 102 and core network element 106 for sending and receiving data (e.g., OFDMA symbol(s)). A transmitting node (also referred to herein as a transmission apparatus, transmission circuit, or a transmitter, e.g., a BS or a UE) may generate the OFDMA symbol(s) and transmit the symbol to a receiving device (also referred to herein as a receiver apparatus, receiving circuit, or a receiver, e.g., a UE or a BS). When the receiving device receives the symbol(s), the receiver may perform the methods described in the present disclosure to use both a reference signal and a data signal to improve the ability of the receiver to successfully receive the symbol (s).

[0051] Each node of wireless network 100 in FIG. 1 that is suitable for the reception of signals, such as OFDMA signals, may be considered as a receiving device. More detail regarding the possible implementation of a receiving device is provided by way of example in the description of a communications device 2200 in FIG. 22. Communications device 2200 may be configured as user equipment 102, access node 104, or core network element 106 in FIG. 1. Similarly, communications device 2200 may also be configured as computer 110, router 114, tablet 112, database 116, or authentication server 118 in FIG. 1. As shown in FIG. 22, communications device 2200 may include a processor 2202, a memory 2204, and a transceiver 2206. These components are shown as connected to one another by a bus, but other connection types are also permitted. When communications device 2200 is user equipment 102, additional components may also be included, such as a user interface (UI), sensors, and the like. Similarly, communications device 2200 may be implemented as a blade in a server system when communications device 2200 is configured as core network element 106. Other implementations are also possible, and these enumerated examples are not to be taken as limiting.

[0052] Transceiver 2206 may include any suitable device for sending and/or receiving data. Communications device 2200 may include one or more transceivers, although only one transceiver 2206 is shown for simplicity of illustration. An antenna 2208 is shown as a possible communication mechanism for communications device 2200. If the communication is multipleinput and multiple-output (MIMO), multiple antennas and/or arrays of antennas may be utilized for such communication. Additionally, examples of communications device 2200 may communicate using wired techniques rather than (or in addition to) wireless techniques. For example, access node 104 may communicate wirelessly to user equipment 102 and may communicate by a wired connection (for example, by optical or coaxial cables) to core network element 106. Other communication hardware, such as a network interface card (NIC), may be included in communications device 2200 as well.

[0053] As shown in FIG. 22, communications device 2200 may include processor 2202. Although only one processor is shown, it is understood that multiple processors can be included. Processor 2202 may include microprocessors, microcontrollers, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout the present disclosure. Processor 2202 may be a hardware device having one or more processing cores. Processor 2202 may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Software can include computer instructions written in an interpreted language, a compiled language, or machine code. Other techniques for instructing hardware are also permitted under the broad category of software. [0054] As shown in FIG. 22, communications device 2200 may also include memory 2204. Although only one memory is shown, it is understood that multiple memories can be included. Memory 2204 can broadly include both memory and storage. For example, memory 2204 may include random-access memory (RAM), read-only memory (ROM), static RAM (SRAM), dynamic RAM (DRAM), ferro-electric RAM (FRAM), electrically erasable programmable ROM (EEPROM), CD-ROM or other optical disk storage, hard disk drive (HDD), such as magnetic disk storage or other magnetic storage devices, Flash drive, solid-state drive (SSD), or any other medium that can be used to carry or store desired program code in the form of instructions that can be accessed and executed by processor 2202. Broadly, memory 2204 may be embodied by any computer-readable medium, such as a non-transitory computer-readable medium.

[0055] Processor 2202, memory 2204, and transceiver 2206 may be implemented in various forms in communications device 2200 for performing wireless communication with iterative correction functions. In some embodiments, processor 2202, memory 2204, and transceiver 2206 of communications device 2200 are implemented (e.g., integrated) on one or more system-on-chips (SoCs). In one example, processor 2202 and memory 2204 may be integrated on an application processor (AP) SoC (sometimes known as a “host,” referred to herein as a “host chip”) that handles application processing in an operating system environment, including generating raw data to be transmitted. In another example, processor 2202 and memory 2204 may be integrated on a baseband processor (BP) SoC (sometimes known as a modem, referred to herein as a “baseband chip”) that converts the raw data, e.g., from the host chip, to signals that can be used to modulate the carrier frequency for transmission, and vice versa, which can run a real-time operating system (RTOS). In still another example, processor 2202 and transceiver 2206 (and memory 2204 in some cases) may be integrated on an RF SoC (sometimes known as a transceiver, referred to herein as an “RF chip”) that transmits and receives RF signals with antenna 2208. It is understood that in some examples, some or all of the host chip, baseband chip, and RF chip may be integrated as a single SoC. For example, a baseband chip and an RF chip may be integrated in a single SoC that manages all the radio functions for cellular communication.

[0056] Various aspects of the present disclosure related to phase tracking signals may be implemented as software and/or firmware elements executed by a generic processor in a baseband chip (e.g., a baseband processor). It is understood that in some examples, one or more of the software and/or firmware elements may be replaced by dedicated hardware components in the baseband chip, including integrated circuits (ICs), such as application-specific integrated circuits (ASICs). Mapping to the wireless communication (e.g., WI-FI, 4G, LTE, 5G, etc.) layer architecture, the implementation of the present disclosure may be at Layer 1, e.g., the physical (PHY) layer.

[0057] FIG. 2 illustrates an example of a reference signal (RS) configuration. The RS structure of 5G new radio (NR) basically follows that of long-term evolution (LTE) while achieving the flexibility to adapt to operation in various different frequency bands and scenarios. [0058] To increase protocol efficiency and to keep transmissions contained within a slot or beam without having to depend on other slots and beams, 5G NR introduces the following four main reference signals. Specifically, 5G NR introduces a demodulation reference signal (DMRS), a phase tracking reference signal (PT-RS), a sounding reference signal (SRS), and a channel state information reference signal (CSI-RS).

[0059] For example, these reference signals differentiate between NR and LTE. In NR, there is not a cell-specific reference signal (C-RS). Also, a new reference signal PT-RS has been introduced for time/frequency tracking. DMRS is used for both downlink and uplink channels. Further, in NR, reference signals are transmitted only when necessary, by contrast to LTE, which always exchanges reference signals to manage the link.

[0060] The reference signals include a DMRS. The DMRS is specific for specific UE and is used to estimate the radio channel. The system is able to beamform the DMRS, keep it within a scheduled resource, and transmit it only when necessary in either DL or UL. Further, multiple orthogonal DMRSs may be allocated to support MIMO transmission. Thus, the network presents users with DMRS information early on for the initial decoding requirement that low-latency applications need, but the network only occasionally presents this information for low-speed scenarios in which the channel shows little change. In high-mobility scenarios, to track fast changes in a channel, a system might increase the rate of transmission of the DMRS signal (called “additional DMRS”). As noted above, DMRS refers to the demodulation reference signal. DMRS is used by a receiver for radio channel estimation for demodulation of associated physical channel DMRS design, and mapping is specific to each downlink (DL) and uplink (UL) NR channels such as NR-PBCH, NR-PDCCH, NR-PDSCH, NR-PUSCH, and NR- PUSCH. A DMRS is generated to be specific for a specific UE and is then transmitted on demand. A DMRS may be a beamformed DMRS and may be kept within a scheduled resource. A DMRS may be transmitted only when necessary in either DL or UL. Also, multiple orthogonal DMRSs may be allocated simultaneously to support MIMO transmission.

[0061] The reference signals may also include a PT-RS. The phase noise of a transmitter increases as the frequency of operation increases. The PT-RS plays an important role, especially at mmWave frequencies, to minimize the effect of the oscillator phase noise on system performance. One of the main problems that phase noise introduces into an OFDM signal appears as a common phase rotation of all the sub-carriers, known as common phase error (CPE). As noted above, PT-RS stands for phase tracking reference signal. The main function of the PT-RS is to track a phase of the local oscillator at a transmitter and a receiver. A PT-RS enables suppression of phase noise and common phase error, especially at higher mm-wave frequencies. A PT-RS is present both in uplink (in NR-PUSCH) and downlink (in NR-PDSCH) channels.

[0062] Due to phase noise properties, PT-RS has a low density in a frequency domain and a high density in a time domain. PT-RS is associated with one DMRS port during transmission. Moreover, PT-RS is confined to a scheduled bandwidth (BW) and a duration used for NR- PDSCH/NR-PUSCH. The NR system typically maps the PT-RS information to a few subcarriers per symbol because the phase rotation affects all sub-carriers within an OFDM symbol equally. However, the phase rotation shows a low correlation from symbol to symbol. The system configures the PT-RS depending on the quality of the oscillators, carrier frequency, subcarrier spacing, and modulation and coding schemes that the transmission uses.

[0063] However, as described further below, the configuration of a PT-RS may be different in embodiments because a data signal may substitute for all or part of a PT-RS.

[0064] The reference signals may also include an SRS. As a UL-only signal, the SRS is transmitted by the UE to help the gNB (or another BS) obtain the channel state information (CSI) for each user. CSI describes how the NR signal propagates from the UE to the gNB and represents the combined effect of scattering, fading, and power decay with distance. The system uses the SRS for resource scheduling, link adaptation, Massive MIMO, and beam management. As noted above, SRS refers to a sounding reference signal and is an uplink-only signal. The SRS is configured specifically to a UE. In the time domain, an SRS spans 1/2/4 consecutive symbols which are mapped within the last six symbols of the slot. Multiple SRS symbols may allow coverage extension and increased sounding capacity. The design of SRS and its frequency hopping mechanism are the same as that used in LTE for SRS.

[0065] The reference signals may also include a CSI-RS. As a DL-only signal, the CSI-RS the UE receives is used to estimate the channel and report channel quality information back to the gNB. During MIMO operations, NR uses different antenna approaches based on the carrier frequency. At lower frequencies, the system uses a modest number of active antennas for MU- MIMO and adds frequency division duplex (FDD) operations. In this case, the UE requires the CSI-RS to calculate the CSI and reports it back in the UL direction. As noted above, CSI-RS refers to channel state information reference signal, and the CSI-RS signals themselves are downlink- only signals. For example, a CSI-RS is used for DL CSI acquisition. Also, a CSI-RS is used for RSRP measurements used during mobility and beam management, and also used for frequency/time tracking, demodulation, and UL reciprocity-based pre-coding. A CSI-RS is configured specifically to a UE, but multiple users can also share the same resource. A 5G NR standard allows a high level of flexibility in CSI-RS configurations, such that a resource can be configured with up to 32 ports. A CSI-RS resource may start at any OFDM symbol of the slot, and it usually occupies 1/2/4 OFDM symbols depending upon the configured number of ports. CSI- RS may be periodic, semi-persistent or aperiodic, due to downlink control information (DCI) triggering. For time/frequency tracking, CSI-RS can either be periodic or aperiodic. A CSI-RS is transmitted in bursts of two or four symbols which are spread across one or two slots.

[0066] As described above, in high-frequency bands, phase noise is a serious issue. Phase noise is phase fluctuation that occurs due to frequency components other than those of the carrier frequency in a local oscillator signal. Therefore, in NR, a Phase-Tracking Reference Signal (PT- RS) is newly specified as a UE-specific reference signal.

[0067] NR also involves beam control techniques. Beam control in LI (the first layer of the Open Systems Interconnection (OSI) reference model (physical layer)) and L2 (the second layer of the OSI reference model (data link layer)) can be divided into beam management and CSI acquisition. Beam management is a particularly effective technique at high frequencies and is generally aimed at establishing and maintaining transmitting/receiving analog beam pairs between the base station and user equipment. For example, the user equipment compares the LI -Reference Signal Received Power (RSRP) of multiple SS/PBCH blocks and CSI-RS to which different beams have been applied by the base station. Here, RSRP refers to the received power of a signal measured at a receiver. RSRP is used as an indicator of the receiver sensitivity of a mobile terminal. The user equipment selects a suitable transmit beam to be reported to the base station. The base station reports the beam information applied to the downlink channel so that the user equipment can select the corresponding reception beam to receive the downlink channel. A beam failure recovery technique is also specified, whereby user equipment that detects deterioration in the characteristics of a base station beam can request a switch to a different beam.

[0068] On the other hand, CSI acquisition is used for purposes such as determining the choice of transmission rank. Transmission rank refers to the number of layers or spatial streams transmitted simultaneously in multiple-input and multiple-output (MIMO), digital beams, and a Modulation and Coding Scheme (MCS). An MCS refers to combinations of modulation scheme and coding rate decided beforehand when performing Adaptive Modulation and Coding. The codebook used for digital beam control may be specified as Type I and Type II, which have relatively low and relatively high quantization granularity, respectively. Quantization granularity refers to the spatial granularity of beams that are capable of being formed. In Type II, digital beam control refers to information about two beams and their linear combination. A linear combination refers to a linear sum of vectors. The vectors are multiplied by constant factors and added together. Then, information is reported to the base station, enabling beam control with higher spatial granularity.

[0069] Thus, FIG. 2 and the above discussion provide background for typical reference signals in 5G NR. These typical reference signals are modified, as described further below in examples, to improve performance.

[0070] FIG. 3 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure.

[0071] Accurate phase compensation is needed for a high modulation and coding scheme (MCS) operating at high SNR, while low MCS is not as sensitive to phase noise. For any communication technology, an MCS defines the numbers of useful bits which can be carried by one symbol. For example, in 5G, a symbol is defined as a resource element (RE), and an MCS is defined as how many useful bits can be transmitted per RE.

[0072] Because of this property in which a low MCS is not as sensitive to phase noise, it is possible to send traffic in part of resources with an MCS lower than the MCS scheduled in the rest of the resource elements. Such traffic is referred to as traffic resource element (RE) with reduced spectral efficiency (TRRSE) data path. Because an operating SNR for such data is much larger than required by the reduced spectral efficiency, the demodulation raw bit error rate (BER) of a TRRSE data path is equal to or close to zero. As a result, a receiver may easily recover a TRRSE data path with very low raw BER and accordingly reconstruct the signal of the TRRSE data path sent by a transmitter and use it to estimate phase noise.

[0073] In an embodiment, a PT-RS is replaced with a TRRSE (traffic RE with reduced spectral efficiency) data path in resource allocation. In such examples, TRRSETimeDensity and TRRSEFrequencyDensity are defined as the presence and time density of the TRRSE data path and the presence and frequency density of the TRRSE data path, respectively.

[0074] FIG. 21 A is a tabular diagram showing a solution with TRRSETimeDensity = 1. FIG. 2 IB is a tabular diagram showing a solution with TRRSETimeDensity = 2. TRRSE is present in every symbol in FIG. 21 A, while TRRSE is present in every two symbols in FIG. 21B. Table 1 below shows a time density of TRRSE as a function of a scheduled MCS, where IMCS is the scheduled MCS, K is the number of MCS thresholds, and TRRSE MCSk, and k=l, ..., K are threshold parameters. Table 1 : Time Density of TRRSE as a Function of Scheduled MCS IMCS

[0075] In an embodiment, the MCS used in a TRRSE data path is a function of a scheduled MCS and a scheduled rank. In some embodiments, 1 -layer transmission is used in a TRRSE data path. Also, in some embodiments, the rank used in a TRRSE data path is a function of a scheduled MCS and a scheduled rank. An MCS in a TRRSE data path may use a different coding rate and/or different modulations from a scheduled MCS. The corresponding transmitter of such a TRRSE data path is shown in FIG. 3, FIG. 4, FIG. 5, and FIG. 6. In embodiments as shown in FIG. 3, FIG. 4, FIG. 5, and FIG. 6, interleaving is present in neither, either, or both traffic data paths.

[0076] In embodiments as shown in FIG. 4 and FIG. 6, two separate encoders can use different coding methods or the same coding methods. For example, both encoders use low-density parity check (LDPC) encoders in some embodiments. One encoder is an LDPC encoder, and the other encoder is a polar encoder in some embodiments. One encoder is a turbo encoder, and the other is a convolutional encoder in some embodiments. In embodiments as shown in FIG. 3, FIG. 4, FIG. 5, and FIG. 6, information bits sent on the TRRSE data path may have any relationship with information bits sent on a normal traffic data path. For example, the TRRSE data path bits may be sent before, after, or mixed with the normal traffic data path bits in a transmitter’s queue.

[0077] In another embodiment, a spectral efficiency in the TRRSE data path uses the same coding rate but different modulations or different ranks from a scheduled spectral efficiency. The modulation order used in the TRRSE data path is a function of a scheduled MCS and a scheduled rank. The rank used in the TRRSE data path is also a function of a scheduled MCS and a scheduled rank. A corresponding transmitter is shown in FIG. 7 and FIG. 8. The interleaving may be present in neither, either, or both traffic data paths. TRRSEFrequencyDensity is a function of scheduled bandwidth. Table 2 gives an embodiment of the frequency density of the TRRSE data path, where baseFreqDensity is the smallest frequency density. Table 2: Frequency Density of TRRSE as a Function of Scheduled Bandwidth

[0078] In another embodiment, part of a PT-RS resource is replaced with TRRSE (traffic RE with reduced spectral efficiency) resources. PTSTimeDensity and PTSFrequencyDensity are, respectively, defined as the presence and time density and the presence and frequency density of a phase tracking signal (PTS). PTS corresponds to TRRSE resources plus PT-RS resources. PTS thus provides a signal used for phase tracking based on the combined information present in both the TRRSE data path and PT-RS.

[0079] Such an embodiment defines PTRSTimeDensity and PTRSFrequencyDensity as the presence and time density of PT-RS and the presence and frequency density of PT-RS in a phase tracking signal.

[0080] FIGS. 21C, 21D, and 21E show examples with different TimeDensity and PTRSTimeDensity values. For example, FIG. 21C shows a solution with TimeDensity = 1 and PTRSTimeDensity = 2. FIG. 21D shows a solution with TimeDensity =1 and PTRSTimeDensity = 3. FIG. 2 IE shows a solution with TimeDensity = 2 and PTRSTimeDensity = 2.

[0081] Table 3 below shows a time density of a PTS (phase tracking signal) as a function of a scheduled MCS, where IMCS is the scheduled MCS, KI is the number of MCS thresholds, and pts MCSk, and k=l, ..., KI are threshold parameters. Tables 4 and 5, below, show two alternative embodiments for a time density of a PT-RS (phase tracking reference signal) in a PTS as a function of scheduled MCS, where IMCS is the scheduled MCS, K2 is the number of MCS thresholds, and ptrs MCSk, and k=l, ..., K2 are threshold parameters.

Table 3 : Time Density of PTS as a Function of Scheduled MCS IMCS

Table 4: Time Density of PT-RS Inside PTS as a Function of Scheduled MCS IMCS

Table 5: Time Density of PT-RS Inside PTS as a Function of Scheduled MCS IMCS

[0082] In an embodiment, the MCS used in the TRRSE data path is a function of a scheduled MCS and a scheduled rank. In some embodiments, 1-layer transmission is used in the TRRSE data path. In some embodiments, the rank used in the TRRSE data path is a function of the scheduled MCS and the scheduled rank. An MCS in the TRRSE data path uses a different coding rate and/or different modulations from scheduled MCS. A corresponding transmitter for such embodiments is shown in FIG. 10, FIG. 11, FIG. 12, and FIG. 14. In embodiments as shown in FIG. 10, FIG. 11, FIG. 12, and FIG. 14, interleaving is present in neither, either, or both traffic data paths. In FIG. 10, FIG. 11, FIG. 12, and FIG. 14, a PT-RS is also inserted.

[0083] In embodiments as shown in FIG. 11 and FIG. 14, two encoders can use different or the same coding methods. For example, both encoders in these embodiments are LDPC encoders in some embodiments. One encoder is an LDPC, and another is polar in some embodiments. One is turbo, and the other is convolutional in some embodiments. In embodiments shown in FIG. 10, FIG. 11, FIG. 12, and FIG. 14, information bits sent on the TRRSE data path may have any relationship with information bits sent on a standard data path. For example, the former information bits are before or after or mixed with the latter in the transmitter queue.

[0084] In another embodiment, a spectral efficiency in the TRRSE data path uses the same coding rate but different modulations or a different rank from a scheduled spectral efficiency. The modulation order used in the TRRSE data path is a function of the scheduled MCS and the scheduled rank. The rank used in the TRRSE data path is a function of the scheduled MCS and the scheduled rank. The corresponding transmitter of such an embodiment is shown in FIG. 13 and FIG. 14. The interleaving may be present in neither, either, or both traffic data paths.

[0085] PTSFrequencyDensity is a function of the scheduled bandwidth. Also, PTRSFrequencyDensity is a function of the scheduled bandwidth.

[0086] In an embodiment, the TRRSE data path has the same frequency allocation as a PT- RS. In this embodiment, only a frequency density of PTS is defined, and PTRSFrequencyDensity is not defined. FIG. 21F shows a resource allocation for such a PTS. FIG. 21F shows a solution with TimeDensity = 1 and PTRSTimeDensity = 2, and PTRSFrequencyDensity not defined.

[0087] Table 6 gives information related to an embodiment of a Frequency density of a PTS, where baseFreqDensity is the smallest frequency density.

Table 6: Frequency Density of PTS as a Function of Scheduled Bandwidth

[0088] In one embodiment, the TRRSE data path has a different frequency density from the PT-RS. In this embodiment, both a frequency density of PTS and PTRSFrequencyDensity are defined. FIG. 21G and FIG. 21H show resource allocation for such a PTS. For example, FIG. 21G shows a solution with TimeDensity = 1 and PTRSTimeDensity = 2, and PTSFrequencyDensity and PTRSFrequencyDensity defined. FIG. 21H shows a solution with TimeDensity = 1 and PTRSTimeDensity = 2, and PTSFrequencyDensity and PTRSFrequencyDensity defined. According to such an embodiment, Table 7 shows a frequency density of PT-RS as a function of scheduled bandwidth.

Table 7: Frequency density of PT-RS as a Function of Scheduled Bandwidth

[0089] Thus, in FIG. 3, the transmitting device 300 includes a TRRSE data path and a standard data path. The TRRSE data path and the standard data path both provide information for resource mapping module 360. In addition to the TRRSE data path and the standard data path. [0090] In FIG. 3, the transmitting device 300 begins with an encoding module 310. Encoding involves converting the original data into an encoded form that is more suitable for transmission. A number of various encoding algorithms exist and may be used by the encoding module 310. Specific combinations have been described above, along with which data path uses specific encoders, such as low-density parity-check (LDPC) encoders, polar encoders, turbo encoders, and convolutional encoders.

[0091] The encoding module 310 provides its results to several modules at a TRRSE data path, followed by a standard data path. For example, the encoding module 310 provides its results to a rate matching module 322A. Rate matching involves matching the incoming bits to available resources. For example, there may be some resources available for data transmission over the resource grid including all the antennas, time, and subcarriers. The rate matching module 322A has the encoded bits that are required to transmit over those available resources after modulation. Rate matching module 322A rate matches these encoded bits to those available resources either by repeating a few of the encoded bits if there are fewer bits than resources or by discarding a few of the encoded bits if there are more bits than resources.

[0092] The rate matching module 322A provides its results to interleaving module 324A. With respect to interleaving, burst errors can be introduced in data during transmission. Interleaving provides a way to address burst errors. Interleaving module 324A spreads user bits in time so that useful information bits are not present in succession. Interleaving module 324A may be optional. For example, interleaving may introduce delays because de-interleaving cannot be performed until all interleaved data is received.

[0093] The interleaving module 324A provides its results to modulation module 326A. Modulation is the method by which one or more parameters of a higher frequency carrier is varied by the actual signal containing user information. Modulation techniques can be analog or digital, but in the present embodiments, the modulation module 326A may use a digital modulation technique. For example, digital modulation may provide higher capacity, more information security, better utilization of resources, greater robustness, and better quality.

[0094] The modulation module 326A provides its results to layer mapping module 328A. Layer mapping is the process where each codeword is mapped to one or multiple layers.

[0095] The layer mapping module 328A provides its results to transform precoding module 330A. Transform precoding is a first operation to creating an OFDM waveform by spreading UL data in a special way to reduce Peak-to-Average Power Ratio (PAPR) of the waveform. For example, transform precoding may involve a Digital Fourier Transform (DFT) operation.

[0096] The transform precoding module 330A provides its results to precoding module 332A. Precoding is the process where the layer data are allocated to multiple antenna ports. The precoding module 332A provides its results to resource mapping module 360.

[0097] As described above, in FIG. 3, there is no PT-RS generated or used. Thus, the information from the TRRSE data path is used to generate a PTS, and such a PTS is used for phase tracking when the standard data path is used to transmit data.

[0098] Accordingly, data may then be transmitted along a standard data path using similar modules. For example, a standard data path may use rate matching module 322B, interleaving module 324B, modulation module 326B, layer mapping module 328B, transform precoding module 330B, and precoding module 332B in a similar manner, to provide information to resource mapping module 360 for transmission.

[0099] FIG. 4 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure. FIG. 4 is largely similar to FIG. 3 with respect to the transmission apparatus it characterizes. Thus, FIG. 4 includes rate matching modules 422A and 422B, interleaving modules 424A and 424B, modulation modules 426A and 426B, layer mapping modules 428A and 428B, transform precoding modules 430A and 430B, and precoding modules 432A and 432B. However, FIG. 4 differs from FIG. 3 in that there are separate encoding modules 410A and 410B for the respective data paths. These modules provide their results to resource mapping module 460 for transmission.

[0100] FIG. 5 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure. FIG. 5 is generally similar to FIG. 3 with respect to the transmission apparatus it characterizes. Thus, FIG. 5 includes encoding module 510, rate matching modules 522A and 522B, interleaving modules 524A and 524B, modulation modules 526A and 526B, and layer mapping modules 528 A and 528B. However, FIG. 5 differs from FIG. 3 in that there are antenna port mapping modules 540A and 540B, which provide an alternative way to map resources to the antenna for the respective data paths, rather than transform precoding modules 330A and 330B and precoding modules 332A and 332B. These modules provide their results to resource mapping module 560 for transmission.

[0101] FIG. 6 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure. FIG. 6 is largely similar to FIG. 3 with respect to the transmission apparatus it characterizes. Thus, FIG. 6 includes rate matching modules 622A and 622B, interleaving modules 624A and 624B, modulation modules 626A and 626B, and layer mapping modules 628 A and 628B. However, FIG. 6 differs from FIG. 3 in that there are separate encoding modules 610A and 61 OB for the respective data paths. FIG. 6 also differs from FIG. 3 in that there are antenna port mapping modules 640A and 640B for the respective data paths, rather than transform precoding modules 330A and 330B and precoding modules 332A and 332B. These modules provide their results to resource mapping module 660 for transmission.

[0102] FIG. 7 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure. FIG. 7 is largely similar to FIG. 3 with respect to the transmission apparatus it characterizes. Thus, FIG. 7 includes encoding module 710, interleaving modules 724A and 724B, modulation modules 726A and 726B, layer mapping modules 728A and 728B, transform precoding modules 730A and 730B, and precoding modules 732A and 732B. However, FIG. 7 differs from FIG. 3 in that there is a single rate matching module 722 used for both of the respective data paths. These modules provide their results to resource mapping module 760 for transmission.

[0103] FIG. 8 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure. FIG. 8 is largely similar to FIG. 3 with respect to the transmission apparatus it characterizes. Thus, FIG. 8 includes encoding module 810, interleaving modules 824A and 824B, modulation modules 826A and 826B, and layer mapping modules 828A and 828B. However, FIG. 8 differs from FIG. 3 in that there is a single rate matching module 822 used for both of the respective data paths. FIG. 8 also differs from FIG. 3 in that there are antenna port mapping modules 840A and 840B for the respective data paths, rather than transform precoding modules 330A and 330B and precoding modules 332A and 332B. These modules provide their results to resource mapping module 860 for transmission.

[0104] FIG. 9 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure. FIG. 9 is largely similar to FIG. 3 with respect to the transmission apparatus it characterizes. Thus, FIG. 9 includes encoding module 910, rate matching modules 922A and 922B, interleaving modules 924A and 924B, modulation modules 926A and 926B, layer mapping modules 928A and 928B, transform precoding modules 930A and 930B, and precoding modules 932A and 932B. However, FIG. 9 differs from FIG. 3 in that there is also a PT-RS generation module 950 that provides a PT-RS for use along with the TRRSE data path. These modules provide their results to resource mapping module 960 for transmission.

[0105] FIG. 10 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure. FIG. 10 is largely similar to FIG. 3 with respect to the transmission apparatus it characterizes. Thus, FIG. 10 includes rate matching modules 1022A and 1022B, interleaving modules 1024 A and 1024B, modulation modules 1026 A and 1026B, layer mapping modules 1028A and 1028B, transform precoding modules 1030A and 1030B, and precoding modules 1032A and 1032B. However, FIG. 10 differs from FIG. 3 in that there are separate encoding modules 1010A and 1010B for the respective data paths. However, FIG. 10 differs from FIG. 3, in that there is also a PT-RS generation module 1050 that provides a PT-RS for use along with the TRRSE data path. These modules provide their results to resource mapping module 1060 for transmission.

[0106] FIG. 11 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure. FIG. 11 is generally similar to FIG. 3 with respect to the transmission apparatus it characterizes. Thus, FIG. 11 includes encoding module 1110, rate matching modules 1122A and 1122B, interleaving modules 1124A and 1124B, modulation modules 1126A and 1126B, and layer mapping modules 1128A and 1128B. However, FIG. 11 differs from FIG. 3 in that there are antenna port mapping modules 1140A and 1140B for the respective data paths, rather than transform precoding modules 330A and 330B, and precoding modules 332A and 332B. Also, FIG. 11 differs from FIG. 3 in that there is also a PT-RS generation module 1150 that provides a PT-RS for use along with the TRRSE data path. These modules provide their results to resource mapping module 1160 for transmission.

[0107] FIG. 12 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure. FIG. 12 is largely similar to FIG. 3 with respect to the transmission apparatus it characterizes. Thus, FIG. 12 includes rate matching modules 1222A and 1222B, interleaving modules 1224A and 1224B, modulation modules 1226A and 1226B, and layer mapping modules 1228 A and 1228B. However, FIG. 12 differs from FIG. 3 in that there are separate encoding modules 1210A and 1210B for the respective data paths. However, FIG. 12 differs from FIG. 3 in that there are antenna port mapping modules 1240 A and 1240B for the respective data paths, rather than transform precoding modules 330A and 330B, and precoding modules 332A and 332B. Also, FIG. 12 differs from FIG. 3 in that there is also a PT-RS generation module 1250 that provides a PT-RS for use along with the TRRSE data path. These modules provide their results to resource mapping module 1260 for transmission.

[0108] FIG. 13 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure. FIG. 13 is largely similar to FIG. 3 with respect to the transmission apparatus it characterizes. Thus, FIG. 13 includes encoding module 1310, interleaving modules 1324A and 1324B, modulation modules 1326A and 1326B, layer mapping modules 1328A and 1328B, transform precoding modules 1330A and 1330B, and precoding modules 1332A and 1332B. However, FIG. 13 differs from FIG. 3 in that there is a single rate matching module 1322 for the respective data paths. Also, FIG. 13 differs from FIG. 3, in that there is also a PT-RS generation module 1350 that provides a PT-RS for use along with the TRRSE data path. These modules provide their results to resource mapping module 1360 for transmission. [0109] FIG. 14 illustrates a block diagram of a transmission apparatus, according to some embodiments of the present disclosure. FIG. 14 is largely similar to FIG. 3 with respect to the transmission apparatus it characterizes. Thus, FIG. 14 includes encoding module 1410, interleaving modules 1424A and 1424B, modulation modules 1426A and 1426B, and layer mapping modules 1428A and 1428B. However, FIG. 14 differs from FIG. 3 in that there is a single rate matching module 1422 for the respective data paths. Further, FIG. 14 differs from FIG. 3 in that there are antenna port mapping modules 1440 A and 1440B for the respective data paths, rather than transform precoding modules 330A and 330B, and precoding modules 332A and 332B. Also, FIG. 14 differs from FIG. 3 in that there is also a PT-RS generation module 1450 that provides a PT-RS for use along with the TRRSE data path. These modules provide their results to resource mapping module 1460 for transmission.

[0110] FIGS. 15A and 15B illustrate block diagrams of an apparatus including a host chip, a radio frequency (RF) chip, and a baseband chip implementing a wireless communication system according to some embodiments of the present disclosure.

[OHl] It is contemplated that the wireless communication systems described above may be implemented either in software or hardware. For example, FIGS. 15A and 15B illustrate block diagrams of a wireless communication system 1500 including a host chip, an RF chip, and a baseband chip implementing a wireless communication system with phase tracking signals as presented in FIGS. 3-14 in software and hardware, respectively, according to some embodiments of the present disclosure. Wireless communication system 1500 may be an example of any node of wireless network 100 in FIG. 1 suitable for signal reception, such as user equipment 102 or a core network element 106. As shown in FIGS. 15A and 15B, wireless communication system 1500 may include an RF chip 1502, a baseband chip 1504A in FIG. 15A or baseband chip 1504B in FIG. 15B, a host chip 1506, and an antenna 1510. In some embodiments, baseband chip 1504A or 1504B is implemented by processor 2202 and memory 2204, and RF chip 1502 is implemented by processor 2202, memory 2204, and transceiver 2206, as described in greater detail below, with respect to FIG. 22. Besides on-chip memory 1512 (also known as “internal memory,” e.g., as registers, buffers, or caches) on each chip 1502, 1504A or 1504B, or 1506, wireless communication system 1500 may further include a system memory 1508 (also known as the main memory) that can be shared by each chip 1502, 1504A or 1504B, or 1506 through the main bus. Baseband chip 1504A or 1504B is illustrated as a standalone system on a chip (SoC) in FIGS. 15A and 15B. However, it is understood that in one example, baseband chip 1504A or 1504B and RF chip 1502 may be integrated as one SoC; in another example, baseband chip 1504A or 1504B and host chip 1506 may be integrated as one SoC; in still another example, baseband chip 1504A or 1504B, RF chip 1502, and host chip 1506 may be integrated as one SoC, as described above.

[0112] In the uplink, host chip 1506 may generate original data and send it to baseband chip 1504A or 1504B for processing such as encoding, modulation, and resource mapping. For example, this processing includes encoding, rate matching, interleaving, modulation, and layer mapping, as well as transform precoding and precoding or antenna port mapping, as well as optional generation of the PT-RS. Baseband chip 1504A or 1504B may access the original data from host chip 1506 directly using an interface 1514 or through system memory 1508 and then prepare the data for processing upon receipt by performing the functions of the modules provided for the TRRSE data path and the standard data path, as described above in detail with respect to FIGS. 3-14, as non-limiting examples. Baseband chip 1504A or 1504B then may pass the modulated signal (e.g., the OFDMA symbol) to RF chip 1502 through interface 1514. A transmitter (Tx) 1516 of RF chip 1502 may convert the modulated signals in the digital form from baseband chip 1504A or 1504B into analog signals, i.e., RF signals, and transmit the RF signals through antenna 1510 into the channel.

[0113] In the downlink, antenna 1510 may receive the RF signals (e.g., the OFDMA symbol) through the channel and pass the RF signals to a receiver (Rx) 1518 of RF chip 1502. RF chip 1502 may perform any suitable front-end RF functions, such as filtering, down-conversion, or sample-rate conversion, and convert the RF signals into low-frequency digital signals (baseband signals) that can be processed by baseband chip 1504A or 1504B. In the downlink, interface 1514 of baseband chip 1504A or 1504B may receive the baseband signals, for example, the OFDMA symbol. Baseband chip 1504A or 1504B then may perform the phase tracking signal functions of the modules as described above in further detail with respect to FIGS. 3-14 and the other figures, as non-limiting examples. The original data may be extracted by baseband chip 1504A or 1504B from the baseband signals and passed to host chip 1506 through interface 1514 or stored into system memory 1508.

[0114] In some embodiments, the phase tracking schemes disclosed herein (e.g., by wireless communication system 1500) may be implemented in firmware and/or software by baseband chip 1504A in FIG. 15A having a phase tracking module, which may include firmware and/or software, where the phase tracking module may be implemented and executed by a phase tracking processor, such as baseband processor 1520 executing the stored instructions, as illustrated in FIG. 15 A. Baseband processor 1520 may be a generic processor, such as a central processing unit or a digital signal processor (DSP), not dedicated to phase tracking signal management. That is, baseband processor 1520 is also responsible for any other functions of baseband chip 1504A and can be interrupted when performing phase tracking due to other processes with higher priorities. Each element in wireless communication system 1500 may be implemented as a software module executed by baseband processor 1520 to perform the respective functions described above in detail.

[0115] In some other embodiments, the phase tracking schemes disclosed herein, for example, by wireless communication system 1500, may be implemented in hardware by baseband chip 1504B in FIG. 15B having a dedicated phase tracking circuit 1522 such as phase tracking circuit 1522, as illustrated in FIG. 15B. Phase tracking circuit 1522 may include one or more integrated circuits (ICs), such as application-specific integrated circuits (ASICs), dedicated to implementing the phase tracking schemes disclosed herein. Each element in wireless communication system 1500 may be implemented as a circuit to perform the respective functions described above in detail. One or more microcontrollers (not shown) in baseband chip 1504B may be used to program and/or control the operations of phase tracking circuit 1522. It is understood that in some examples, the phase tracking schemes disclosed herein may be implemented in a hybrid manner, e.g., in both hardware and software. For example, some elements in wireless communication system 1500 may be implemented as a software module executed by baseband processor 1520, while some elements in wireless communication system 1500 may be implemented as circuits.

[0116] FIG. 16 is a sequence diagram for an apparatus for managing phase tracking signals, according to some embodiments of the present disclosure. Thus, FIG. 16 is a sequence diagram showing interactions between a base station and a user equipment in a channel state information signal management process.

[0117] Accordingly, in operation S1602, the BS generates and transmits a PT-RS. As described, the PT-RS is a reference signal that aids in tracking phase noise. Operation SI 602 is an optional operation because in some embodiments, the TRRSE resource elements may substitute entirely for the PT-RS. However, even if a PT-RS is used, the sent PT-RS uses fewer occupied resources, because of the use of the TRRSE approach.

[0118] In operation SI 604, the BS modulates TRRSE resource elements using a first spectral efficiency. Various approaches to this generation are illustrated and disclosed further in FIGS. 3-14. Additionally, such TRRSE elements are elements with a relatively low MCS, as they are thus not sensitive to phase noise.

[0119] In operation S1606, the BS transmits the PT-RS and the modulated TRRSE resource elements to the UE. The PT-RS and the TRRSE resource elements constitute a PTS that can be used for phase tracking. Such information is thus sent to the UE for use in sending information to the BS.

[0120] In operation SI 608, the BS modulates standard resource elements using a second modulation and coding scheme (MCS). Various approaches to this generation are illustrated and disclosed further in FIGS. 3-14. Additionally, such standard elements are elements with a relatively high MCS and are thus more sensitive to phase noise. As a result, the UE is able to manage the phase noise based on the PTS. According to the described differences between the TRRSE resource elements and the standard resource elements, the first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

[0121] In operation S1610, the BS transmits the PT-RS signal, if present and the modulated

TRRSE resource elements. Together, these signals act as a phase tracking signal which can be used by the UE.

[0122] In operation S 1612, the UE receives the PT-RS and the TRRSE resource elements.

In operation S 1614, the UE performs phase noise estimation based on the PT-RS and the TRRSE resource elements, estimating phase noise information. Accordingly, in operation S 1616, the BS receives the standard resource elements, which are not required to convey phase noise information, and uses the phase noise information from the PTS, where the PTS is a result of combining information from the PT-RS (if present) and the TRRSE resource elements to ensure that the UE receives these standard resource elements successfully in operation S 1616.

[0123] In this manner, it is possible to successfully manage phase noise while minimizing overhead that would otherwise be required to send the full PT-RS.

[0124] It is to be noted that the interaction above has been characterized as being between a BS that generates the PT-RS signal, the TRRSE signal, and the standard resource element signal, and a UE that receives such a signal. However, the reverse interaction, in which the UE sends such signals for receipt by a BS, is also possible in other embodiments, and a similar disclosure applies, with the roles of the elements reversed. Thus, FIG. 16 shows how a BS or a UE form a connection, and one of these elements generates and transmits a PT-RS signal and TRRSE resource elements [0125] FIG. 17A illustrates a flowchart of a method for managing phase tracking signals in a transmitter, according to an embodiment of the present disclosure. For example, in various embodiments, the transmitter is a BS or a UE.

[0126] In operation SI 702, the method performs encoding. In operation SI 704, the method performs rate matching. In operation SI 706, the method performs interleaving. In operation SI 708, the method performs modulation. In operation S 1710, the method performs layer mapping. In operation S1712, the method performs transform precoding. In operation S1714, the method performs precoding. Each of these operations is potentially performed for each of a TRRSE data path and a standard data path, as described above with respect to FIGS. 3, 4, and 7. In operation S1730, the method concludes by performing resource mapping, such that signals are sent to a receiver. Thus, FIG. 17A shows a way of transmitting data over TRRSE and standard data paths that minimizes overhead.

[0127] FIG. 17B illustrates a flowchart of a method for managing phase tracking signals in a transmitter, according to an embodiment of the present disclosure. For example, in various embodiments, the transmitter is a BS or a UE.

[0128] In operation SI 702, the method performs encoding. In operation SI 704, the method performs rate matching. In operation SI 706, the method performs interleaving. In operation SI 708, the method performs modulation. In operation S 1710, the method performs layer mapping. In operation S1718, the method performs antenna port matching. Each of these operations is potentially performed for each of a TRRSE data path and a standard data path as described above with respect to FIGS. 5, 6, and 8. In operation SI 730, the method concludes by performing resource mapping, such that signals are sent to a receiver. Thus, FIG. 17B shows a way of transmitting data over TRRSE and standard data paths that minimizes overhead.

[0129] FIG. 17C illustrates a flowchart of a method for managing phase tracking signals in a transmitter, according to an embodiment of the present disclosure. For example, in various embodiments, the transmitter is a BS or a UE.

[0130] In operation SI 702, the method performs encoding. In operation SI 704, the method performs rate matching. In operation SI 706, the method performs interleaving. In operation SI 708, the method performs modulation. In operation S 1710, the method performs layer mapping. In operation S1712, the method performs transform precoding. In operation S1714, the method performs precoding. Each of these operations is potentially performed for each of a TRRSE data path and a standard data path, as described above with respect to FIGS. 9, 10, and 13. In operation S1730, the method concludes by performing resource mapping, such that signals are sent to a receiver. Thus, FIG. 17C shows a way of transmitting data over TRRSE and standard data paths that minimizes overhead.

[0131] FIG. 17D illustrates a flowchart of a method for managing phase tracking signals in a transmitter, according to an embodiment of the present disclosure. For example, in various embodiments, the transmitter is a BS or a UE.

[0132] In operation SI 702, the method performs encoding. In operation SI 704, the method performs rate matching. In operation SI 706, the method performs interleaving. In operation SI 708, the method performs modulation. In operation S 1710, the method performs layer mapping. In operation S1712, the method performs transform precoding. In operation S1714, the method performs precoding. Each of these operations is potentially performed for each of a TRRSE data path and a standard data path, as described above with respect to FIGS. 11, 12, and 14. In operation S1730, the method concludes by performing resource mapping, such that signals are sent to a receiver. Thus, FIG. 17D shows a way of transmitting data over TRRSE and standard data paths that minimizes overhead.

[0133] FIG. 18 illustrates a flowchart of a method for managing phase tracking signals in a receiver, according to some embodiments of the present disclosure. For example, in various embodiments, the receiver is a UE or a BS.

[0134] In operation SI 802, the method receives the PT-RS. As described, such a PT-RS may use fewer resources compared to those of a typical PT-RS, due to the use of TRRSE resource elements. In fact, in some embodiments, the method does not even use operation SI 802, because the TRRSE data path may entirely substitute for the PT-RS.

[0135] In operation SI 804, the method receives TRRSE resource elements. As described, these TRRSE elements may be arranged in various ways to replace all or some of the PT-RS information that would otherwise be required. The TRRSE includes information that is usable for phase tracking, which allows it to act as a substitute for the PT-RS.

[0136] In operation SI 806, the method estimates phase noise information. Such phase noise information is derived from the TRRSE resource elements. Aspects of how such phase noise information is estimated are described further in other portions of this disclosure. For example, FIGS. 3-14 show numerous examples of a TRRSE data path, some of which include a PT-RS as well. These figures show that the TRRSE data path provides information to resource mapping modules, and thus the usefulness of a PT-RS is diminished or eliminated.

[0137] In operation SI 808, the method receives standard resource elements. The standard resource elements may be received by using the phase noise information. Thus, even though the standard resource elements may not be as reliable as the TRRSE resource elements, it is possible to reliably receive the standard resource elements based on phase noise information from the PTS, which combines the PT-RS (if available) and the TRRSE resources, such that phase tracking information from these different sources allows for a standard data path once the phase tracking is in place.

[0138] In operation SI 830, the method ends. Because the TRRSE has allowed for estimating phase noise information, it is possible to share information successfully, even though the PT-RS requires fewer symbols than would otherwise be necessary.

[0139] FIG. 19 is a block diagram of a transmission apparatus 1900 for managing phase tracking signals, according to some embodiments of the present disclosure. For example, FIG. 19 illustrates PT-RS transmission circuit 1910, TRRSE transmission circuit 1920, and standard resource element transmission circuit 1950, and illustrates the subunits that provide hardware to implement the phase noise management of FIGS. 3-14. Specifically, TRRSE transmission circuit 1920 includes encoding circuit 1922 A, rate matching circuit 1924 A, interleaving circuit 1926 A, modulating circuit 1928A, and layer mapping circuit 1930A. TRRSE transmission circuit 1920 may also include various additional constituent circuits. In some embodiments, the TRRSE transmission circuit 1920 includes transform precoding circuit 1932A and precoding circuit 1934A. In other embodiments, the TRRSE transmission circuit 1920 includes antenna port mapping circuit 1936 A.

[0140] The standard resource element transmission circuit 1950 includes related constituent circuits, as appropriate. Specifically, standard resource element transmission circuit 1950 includes encoding circuit 1922B, rate matching circuit 1924B, interleaving circuit 1926B, modulating circuit 1928B, and layer mapping circuit 1930B. The standard resource element transmission circuit may also include transform precoding circuit 1932B, precoding circuit 1934B, and antenna port mapping circuit 1936B, as described above. These related circuits act in a similar way to those of the TRRSE transmission circuit 1920, but the standard resource elements are not relied upon for phase tracking. These constituent circuits correspond to the relevant modules of FIGS. 3-14 and the operations of the methods of FIGS. 17A-17D and illustrate how these other figures may be implemented in portions of specialized hardware.

[0141] FIG. 20 is a block diagram of a receiving apparatus 2000 for managing phase tracking signals, according to some embodiments of the present disclosure. FIG. 20 illustrates a PT-RS receiving circuit 2010, a TRRSE receiving circuit 2020, a phase noise estimation circuit 2030, and a standard receiving circuit 2040. These circuits correspond to the related operations of FIG. 18, and act accordingly to implement the receiving functionality in hardware.

[0142] According to one aspect of the present disclosure, an apparatus including at least one processor and a memory storing instructions is disclosed. The instructions, when executed by the at least one processor, cause the apparatus to modulate traffic resource element with reduced spectral efficiency (TRRSE) resource elements using a first spectral efficiency. The instructions, when executed by the at least one processor, further cause the apparatus to transmit the modulated TRRSE resource elements to a receiver using a TRRSE data path. The instructions, when executed by the at least one processor, further cause the apparatus to modulate standard resource elements by a second spectral efficiency. The instructions, when executed by the at least one processor, further cause the apparatus to transmit the modulated standard resource elements to the receiver using a standard data path. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

[0143] In some embodiments, the TRRSE resource elements entirely replace a phase tracking reference signal (PT-RS), and the apparatus does not transmit a PT-RS.

[0144] In some embodiments, the TRRSE resource elements partially replace a phase tracking reference signal (PT-RS), and the apparatus transmits a PT-RS with either one or both of reduced frequency density and reduced time density.

[0145] In some embodiments, the TRRSE data path and the standard data path include a shared encoding operation.

[0146] In some embodiments, the TRRSE data path and the standard data path each include a separate encoding operation.

[0147] In some embodiments, the TRRSE data path and the standard data path use different encoding schemes or a same encoding scheme.

[0148] In some embodiments, both the TRRSE data path and the standard data path use a low-density parity-check (LDPC) encoding scheme.

[0149] In some embodiments, one data path of the TRRSE data path and the standard data path uses an LDPC encoding scheme and another data path of the TRRSE data path, and the standard data path uses a polar encoding scheme.

[0150] In some embodiments, one data path of the TRRSE data path and the standard data path uses a turbo encoding scheme and another data path of the TRRSE data path, and the standard data path uses a convolutional encoding scheme.

[0151] In some embodiments, each transmitting further includes a modulation operation.

[0152] In some embodiments, each transmitting further includes a rate matching operation.

[0153] In some embodiments, each transmitting further includes any one or any combination of any two or more of layer mapping, transform precoding, and precoding.

[0154] In some embodiments, information bits sent on the TRRSE data path are sent before, sent after, or sent mixed with, information bits sent on the standard data path.

[0155] In some embodiments, the first spectral efficiency in the TRRSE data path uses a same coding rate but a different modulation or a different rank from a scheduled spectral efficiency.

[0156] In some embodiments, a rank used in the TRRSE data path is a function of a scheduled modulation and coding scheme (MCS) and a scheduled rank.

[0157] In some embodiments, a frequency density used in the TRRSE data path is a function of scheduled bandwidth.

[0158] In some embodiments, a modulation and coding scheme (MCS) used in the TRRSE data path is a function of a scheduled MCS and a scheduled rank.

[0159] In some embodiments, the TRRSE data path, the standard data path, or both data paths further include interleaving.

[0160] According to another aspect of the present disclosure, a method for wireless communication is disclosed. The method includes modulating traffic resource element with reduced spectral efficiency (TRRSE) resource elements using a first spectral efficiency. The method further includes transmitting the modulated TRRSE resource elements to a receiver using a TRRSE data path. The method further includes modulating standard resource elements using a second spectral efficiency. The method further includes transmitting the modulated standard resource elements to the receiver using a standard data path. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

[0161] According to another aspect of the present disclosure, a baseband chip is disclosed. The baseband chip includes a traffic resource element with reduced spectral efficiency (TRRSE) modulation circuit. The TRRSE modulation circuit is configured to modulate TRRSE resource elements using a first spectral efficiency. The baseband chip further includes a TRRSE transmission circuit. The TRRSE transmission circuit is configured to transmit the modulated TRRSE resource elements to a receiver using a TRRSE data path. The baseband chip further includes a standard element modulation circuit. The standard element modulation circuit is configured to modulate standard resource elements using a second spectral efficiency. The baseband chip further includes a standard element transmission circuit. The standard element transmission circuit is configured to transmit the modulated standard resource elements to the receiver using a standard data path. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

[0162] According to another aspect of the present disclosure, an apparatus for wireless communication including at least one processor and a memory storing instructions is disclosed. The instructions, when executed by the at least one processor, cause the apparatus to receive traffic resource element with reduced spectral efficiency (TRRSE) resource elements, modulated by a transmitter using a first spectral efficiency, from the transmitter using a TRRSE data path. The instructions, when executed by the at least one processor, further cause the apparatus to estimate phase noise information based on the TRRSE resource elements. The instructions, when executed by the at least one processor, further cause the apparatus to receive standard resource elements, modulated by the transmitter using a second spectral efficiency, from the transmitter using a standard data path based on the phase noise information. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency. [0163] In some embodiments, the TRRSE resource elements entirely replace a phase tracking reference signal (PT-RS), and the apparatus does not receive a PT-RS.

[0164] In some embodiments, the TRRSE resource elements partially replace a phase tracking reference signal (PT-RS), and the apparatus receives a PT-RS with either one or both of reduced frequency density and reduced time density.

[0165] In some embodiments, the TRRSE data path and the standard data path include a shared encoding operation.

[0166] In some embodiments, the TRRSE data path and the standard data path each include a separate encoding operation.

[0167] In some embodiments, the TRRSE data path and the standard data path use different encoding schemes or a same encoding scheme.

[0168] In some embodiments, both the TRRSE data path and the standard data path use a low-density parity-check (LDPC) encoding scheme.

[0169] In some embodiments, one data path of the TRRSE data path and the standard data path uses an LDPC encoding scheme and another data path of the TRRSE data path, and the standard data path uses a polar encoding scheme.

[0170] In some embodiments, one data path of the TRRSE data path and the standard data path uses a turbo encoding scheme and another data path of the TRRSE data path, and the standard data path uses a convolutional encoding scheme.

[0171] In some embodiments, information bits sent on the TRRSE data path are sent before, sent after, or sent mixed with, information bits sent on the standard data path.

[0172] In some embodiments, the first spectral efficiency in the TRRSE data path uses a same coding rate but a different modulation or a different rank from a scheduled spectral efficiency.

[0173] In some embodiments, a rank used in the TRRSE data path is a function of a scheduled modulation and coding scheme (MCS) and a scheduled rank.

[0174] In some embodiments, a frequency density used in the TRRSE data path is a function of a scheduled bandwidth.

[0175] In some embodiments, a modulation and coding scheme (MCS) used in the TRRSE data path is a function of a scheduled MCS and a scheduled rank.

[0176] In some embodiments, the TRRSE data path, the standard data path, or both data paths further include interleaving.

[0177] According to another aspect of the present disclosure, a method for wireless communication is disclosed. The method includes receiving traffic resource element with reduced spectral efficiency (TRRSE) resource elements, modulated by a transmitter using a first spectral efficiency, from the transmitter using a TRRSE data path. The method further includes estimating phase noise information based on the TRRSE resource elements. The method further includes receiving standard resource elements, modulated by the transmitter using a second spectral efficiency, from the transmitter using a standard data path based on the phase noise information. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency. [0178] According to another aspect of the present disclosure, a baseband chip is disclosed. The baseband chip includes a traffic resource element with reduced spectral efficiency (TRRSE) receiving circuit. The TRRSE receiving circuit is configured to receive TRRSE resource elements, modulated by a transmitter using a first spectral efficiency, from the transmitter using a TRRSE data path. The baseband chip further includes a phase noise estimation circuit. The phase noise estimation circuit is configured to estimate phase noise information based on the TRRSE resource elements. The baseband chip further includes a standard resource element receiving circuit. The standard resource element receiving circuit is configured to receive standard resource elements, modulated by the transmitter using a second spectral efficiency, from the transmitter using a standard data path based on the phase noise information. The first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

[0179] A benefit of this technology is, at least, to significantly improve receiver performance by eliminating or reducing overhead that would otherwise be required to send a PT- RS. Based on various quality metrics of the data, data RE substitutes for all or part of a PT-RS when estimating phase noise information. Such estimation is required for successful operation but can be performed without all or some of the PT-RS when data RE of sufficient quality allows.

[0180] Thus, this solution reduces or eliminates the wasted resources that would otherwise be occupied by PT-RS and thereby increases spectral efficiency, such as in an OFDM or OFDMA communication system.

[0181] The foregoing description of the specific embodiments will so reveal the general nature of the present disclosure that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance. [0182] Embodiments of the present disclosure have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

[0183] The Summary and Abstract sections may set forth one or more but not all embodiments of the present disclosure as contemplated by the inventor(s), and thus, are not intended to limit the present disclosure and the appended claims in any way.

[0184] Various functional blocks, modules, and steps are disclosed above. The particular arrangements provided are illustrative and without limitation. Accordingly, the functional blocks, modules, and steps may be re-ordered or combined in different ways than in the examples provided above. Likewise, certain embodiments include only a subset of the functional blocks, modules, and steps, and any such subset is permitted.

[0185] The breadth and scope of the present disclosure should not be limited by any of the above-described embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

35 WHAT IS CLAIMED IS:

1. An apparatus for wireless communication, comprising: at least one processor; and a memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: modulate traffic resource element with reduced spectral efficiency (TRRSE) resource elements using a first spectral efficiency; transmit the modulated TRRSE resource elements to a receiver using a TRRSE data path; modulate standard resource elements using a second spectral efficiency; and transmit the modulated standard resource elements to the receiver using a standard data path, wherein the first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

2. The apparatus of claim 1, wherein the TRRSE resource elements entirely replace a phase tracking reference signal (PT-RS), and the apparatus does not transmit a PT-RS.

3. The apparatus of claim 1, wherein the TRRSE resource elements partially replace a phase tracking reference signal (PT-RS), and the apparatus transmits a PT-RS with either one or both of reduced frequency density and reduced time density.

4. The apparatus of claim 1, wherein the TRRSE data path and the standard data path comprise a shared encoding operation.

5. The apparatus of claim 1, wherein the TRRSE data path and the standard data path each comprise a separate encoding operation.

6. The apparatus of claim 5, wherein the TRRSE data path and the standard data path use different encoding schemes or a same encoding scheme.

7. The apparatus of claim 6, wherein both the TRRSE data path and the standard data path use a low-density parity-check (LDPC) encoding scheme.

8. The apparatus of claim 5, wherein one data path of the TRRSE data path and the standard data path uses an LDPC encoding scheme and another data path of the TRRSE data path, 36 and the standard data path uses a polar encoding scheme.

9. The apparatus of claim 5, wherein one data path of the TRRSE data path and the standard data path uses a turbo encoding scheme and another data path of the TRRSE data path, and the standard data path uses a convolutional encoding scheme.

10. The apparatus of claim 1 , wherein each transmitting further comprises a modulation operation.

11. The apparatus of claim 1, wherein each transmitting further comprises a rate matching operation.

12. The apparatus of claim 1, wherein each transmitting further comprises any one or any combination of any two or more of layer mapping, transform precoding, and precoding.

13. The apparatus of claim 1, wherein information bits sent on the TRRSE data path are sent before, sent after, or sent mixed with, information bits sent on the standard data path.

14. The apparatus of claim 1, wherein the first spectral efficiency in the TRRSE data path uses a same coding rate but a different modulation or a different rank from a scheduled spectral efficiency.

15. The apparatus of claim 1 , wherein a rank used in the TRRSE data path is a function of a scheduled modulation and coding scheme (MCS) and a scheduled rank.

16. The apparatus of claim 1 , wherein a frequency density used in the TRRSE data path is a function of scheduled bandwidth.

17. The apparatus of claim 1, wherein a modulation and coding scheme (MCS) used in the TRRSE data path is a function of a scheduled MCS and a scheduled rank.

18. The apparatus of claim 1, wherein the TRRSE data path, the standard data path, or both data paths further comprise interleaving.

19. A method for wireless communication, comprising: modulating traffic resource element with reduced spectral efficiency (TRRSE) resource elements using a first spectral efficiency; transmitting the modulated TRRSE resource elements to a receiver using a TRRSE data path; modulating standard resource elements using a second spectral efficiency; and transmitting the modulated standard resource elements to the receiver using a standard data path, wherein the first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

20. A baseband chip, comprising: a traffic resource element with reduced spectral efficiency (TRRSE) modulation circuit configured to modulate TRRSE resource elements using a first spectral efficiency; a TRRSE transmission circuit configured to transmit the modulated TRRSE resource elements to a receiver using a TRRSE data path; a standard element modulation circuit configured to modulate standard resource elements using a second spectral efficiency; and a standard element transmission circuit configured to transmit the modulated standard resource elements to the receiver using a standard data path, wherein the first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

21. An apparatus for wireless communication, comprising: at least one processor; and a memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive traffic resource element with reduced spectral efficiency (TRRSE) resource elements, modulated by a transmitter using a first spectral efficiency, from the transmitter using a TRRSE data path; estimate phase noise information based on the TRRSE resource elements; and receive standard resource elements, modulated by the transmitter using a second spectral efficiency, from the transmitter using a standard data path based on the phase noise information, wherein the first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

22. The apparatus of claim 21, wherein the TRRSE resource elements entirely replace a phase tracking reference signal (PT-RS), and the apparatus does not receive a PT-RS.

23. The apparatus of claim 21 , wherein the TRRSE resource elements partially replace a phase tracking reference signal (PT-RS), and the apparatus receives a PT-RS with either one or both of reduced frequency density and reduced time density.

24. The apparatus of claim 21 , wherein the TRRSE data path and the standard data path comprise a shared encoding operation.

25. The apparatus of claim 21 , wherein the TRRSE data path and the standard data path each comprise a separate encoding operation.

26. The apparatus of claim 25, wherein the TRRSE data path and the standard data path use different encoding schemes or a same encoding scheme.

27. The apparatus of claim 26, wherein both the TRRSE data path and the standard data path use a low-density parity-check (LDPC) encoding scheme.

28. The apparatus of claim 25, wherein one data path of the TRRSE data path and the standard data path uses an LDPC encoding scheme and another data path of the TRRSE data path and the standard data path uses a polar encoding scheme.

29. The apparatus of claim 25, wherein one data path of the TRRSE data path and the standard data path uses a turbo encoding scheme and another data path of the TRRSE data path and the standard data path uses a convolutional encoding scheme.

30. The apparatus of claim 21, wherein information bits sent on the TRRSE data path are sent before, sent after, or sent mixed with, information bits sent on the standard data path.

31. The apparatus of claim 21, wherein the first spectral efficiency in the TRRSE data path uses a same coding rate but a different modulation or a different rank from a scheduled spectral efficiency. 39

32. The apparatus of claim 21 , wherein a rank used in the TRRSE data path is a function of a scheduled modulation and coding scheme (MCS) and a scheduled rank.

33. The apparatus of claim 21, wherein a frequency density used in the TRRSE data path is a function of a scheduled bandwidth.

34. The apparatus of claim 21, wherein a modulation and coding scheme (MCS) used in the TRRSE data path is a function of a scheduled MCS and a scheduled rank.

35. The apparatus of claim 21, wherein the TRRSE data path, the standard data path, or both data paths further comprise interleaving.

36. A method for wireless communication, comprising: receiving traffic resource element with reduced spectral efficiency (TRRSE) resource elements, modulated by a transmitter using a first spectral efficiency, from the transmitter using a TRRSE data path; estimating phase noise information based on the TRRSE resource elements; and receiving standard resource elements, modulated by the transmitter using a second spectral efficiency, from the transmitter using a standard data path based on the phase noise information, wherein the first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.

37. A baseband chip, comprising: a traffic resource element with reduced spectral efficiency (TRRSE) receiving circuit configured to receive TRRSE resource elements, modulated by a transmitter using a first spectral efficiency, from the transmitter using a TRRSE data path; a phase noise estimation circuit configured to estimate phase noise information based on the TRRSE resource elements; and a standard resource element receiving circuit configured to receive standard resource elements, modulated by the transmitter using a second spectral efficiency, from the transmitter using a standard data path based on the phase noise information, wherein the first spectral efficiency has a smaller spectral efficiency than the second spectral efficiency.