Polar transmitter time alignment for digital power amplifier

Abstract

This disclosure provides systems, methods, and devices for wireless communications that support improved time alignment in polar transmitters. In a first aspect, a transmitter device includes: a digital power amplifier configured to receive a first input signal corresponding to a first polar vector rotated in a first direction and a second input signal corresponding to a second polar vector rotated in a second direction; a phase modulator circuit coupled to the digital power amplifier and configured to: output a phase modulated signal to the digital power amplifier, wherein the second input signal is based on the phase modulated signal; and a loopback circuit configured to determine a phase shift at an output of the digital power amplifier. In some embodiments, the digital power amplifier is further configured to adjust, based on the phase shift, an RF signal.

Description

2406419W0 1 / 50POLAR TRANSMITTER TIME ALIGNMENT FOR DIGITAL POWER AMPLIFIERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Greece Patent Application No. 20250100211, entitled, “POLAR TRANSMITTER TIME ALIGNMENT FOR DIGITAL POWER AMPLIFIER,” filed on March 24, 2025, which is expressly incorporated by reference herein in its entirety.TECHNICAL FIELD

[0002] Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to radio frequency (RF) processing circuitry for wireless communication systems. Some features may enable and provide improved communications, including improved operation of polar transmitters, such as by improving time alignment in the polar transmitters.INTRODUCTION

[0003] Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources.

[0004] A wireless communication network may include several components. These components may include wireless communication devices, such as base stations (or node Bs) that may support communication for a number of user equipments (UEs). A UE may communicate with a base station via downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station.

[0005] A base station may transmit data and control information on a downlink to a UE or may receive data and control information on an uplink from the UE. On the downlink, a transmission from the base station may encounter interference due to transmissions from neighbor base stations or from other wireless radio frequency (RF) transmitters. On the uplink, a transmission from the UE may encounter interference from uplink transmissions of other UEs communicating with the neighbor base stations or from other wireless RFNRF Ref No. QLXX.P2142WO2406419W0 2 / 50transmitters. This interference may degrade performance on both the downlink and uplink.

[0006] As the demand for mobile broadband access continues to increase, the possibilities of interference and congested networks grows with more UEs accessing the long-range wireless communication networks and more short-range wireless systems being deployed in communities. Furthermore, conventional transmitters of wireless signals for these networks have unacceptably low power efficiency. Research and development continue to advance wireless technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications and increase power efficiency.

[0007] A polar transmitter is a form of transmitter where a signal to be transmitted is separated into an amplitude component and a phase component. Although the use of polar transmission has been found to be more power efficient than conventional transmitters, polar transmitters are typically prone to misalignments in time, which can lead to poor transmission performance. This vulnerability makes polar transmitters difficult to implement in modern wireless networks, as these networks have strong time alignment requirements to keep up with user demands.BRIEF SUMMARY OF SOME EXAMPLES

[0008] The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. This summary is not an extensive overview of all contemplated features of the disclosure and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in summary form as a prelude to the more detailed description that is presented later.

[0009] A polar transmitter may provide much needed power efficiency in modern wireless networks, which have expanded considerably in power consumption due to increased demand. A polar transmitter is a form of transmitter where a signal to be transmitted is separated into an amplitude component and a phase component. The phase component may be used to control an oscillator. The output of the oscillator may then be fed into a power amplifier (e.g., a radio-frequency digital-analog converter (RFDAC)), which may then be modulated using the amplitude component. However, polar transmitters may be NRF Ref No. QLXX.P2142WO2406419W0 3 / 50prone to misalignments in time between amplitude and phase components, leading to a degraded transmission performance. This challenge is exaggerated in modem wireless networks’ strong time alignment requirements to keep up with user demands, as even a 100-picosecond delay may impact user experience.

[0010] Shortcomings mentioned here are only representative and are included to highlight problems that the inventors have identified with respect to existing devices and sought to improve upon. Aspects of devices described below may address some or all of the shortcomings as well as others known in the art. Aspects of the improved devices described herein may present other benefits than, and be used in other applications than, those described above.

[0011] Various embodiments of the present disclosure describe polar transmitter devices and apparatuses for transmission with improved time alignment, and methods of delivering the same. Such devices, apparatuses, and methods may rely on the amplitude modulation (AM) component and a phase modulation (PM) component of a radio frequency (RF) signal. For example, a first polar vector may be determined based on a first input signal corresponding to the AM component, and a second polar vector may be determined based on a second input signal corresponding to the PM component. However, the second polar vector may be coaxially contra-rotated relative to the first polar vector, in order to determine a phase shift in the input signals based on a product of the two polar vectors. For example, as the angular component of each polar vector represents the phase associated the respective input signals (e.g., for the AM or the PM component), a product of the polar vectors may include a summation of these angular components. However, by coaxially contra-rotating the second polar vector, the summation may result in the difference in the phases of the AM and PM components (e.g., based on a summation of positive and negative angular values of the polar vectors, as a result of the second polar vector being coaxially contra-rotated relative to the first polar vector). The difference may indicate a phase shift between the first input signal (representing the AM component of the RF signal) and the second input signal (representing the PM component of the RF signal). The phase shift may be correlated or mapped to a time delay in the signal. The time delay may be used to adjust the signal to correct the time misalignment.

[0012] In various embodiments, devices and apparatuses may include a digital power amplifier configured to receive the AM component of the RF signal as a first input signal and the PM component of the RF signal as a second input signal. The digital power amplifier mayNRF Ref No. QLXX.P2142WO2406419W0 4 / 50be configured to operate in both polar mode (e.g., to facilitate polar modulation) and Cartesian mode (e.g., to receive input signals for quadrature modulation (e.g., in-phase (I) and quadrature (Q) inputs)). The devices and apparatuses may determine (e.g., via a processor) the first and second polar vectors using the first and second input signals, respectively, and determine the phase shift in the signal based on the first and second polar vectors. The devices and apparatuses may determine a time delay (e.g., between the baseband signal and the RF signal) based on the phase shift. Furthermore, the devices and apparatuses may include one or more delay units. The devices and apparatuses may adjust the RF signal based on the time delay to correct the time misalignment. For example, the delay unit may be used to offset the time delay between the baseband signal and the RF signal. Also or alternatively, the delay unit may be used to offset the time delay between the first input signal and the second input signal. Based on the adjustment, a different input signal may be received by the digital power amplifier (e.g., based on an adjusted AM component and / or an adjusted PM component). The aforementioned steps may be repeated until any time misalignment, as measured by the phase shift, is within a tolerance level. In some embodiments, the devices and apparatuses may use a loopback circuit to measure the phase shift to monitor corrections for time misalignment.

[0013] In some embodiments, the circuitry may be configured to operate in an IQ mode during calibration of analog components and / or delay adjustments within the circuitry, and subsequent to calibration switch to a polar mode of operation for using the configured delays.

[0014] In one aspect of the disclosure, a method includes: determining or receiving, by a processor, based on a first input signal representing an amplitude modulation (AM) component of a radiofrequency (RF) signal, a first polar vector; and determining or receiving, by the processor, based on a second input signal representing a phase modulation (PM) component of the RF signal, a second polar vector. The second polar vector is coaxially contra-rotated relative to the first polar vector. The method further includes: determining, by the processor, based on the first polar vector and the second polar vector, a phase shift in the RF signal; and adjusting, by the processor, based on the phase shift, the RF signal.

[0015] In another aspect of the disclosure, a method includes: determining, by a processor, based on a first polar vector representing an amplitude modulation (AM) component of an in- phase quadrature IQ signal and a second polar vector representing a phase modulationNRF Ref No. QLXX.P2142WO2406419W0 5 / 50(PM) component of the IQ signal, a phase shift in the IQ signal, wherein the second polar vector is coaxially contra-rotated relative to the first polar vector; and adjusting, by the processor, based on the phase shift, a radio frequency (RF) signal.

[0016] In some embodiments, adjusting the phase shift includes: offsetting, by the processor, and via a baseband mixer, the phase shift from a baseband signal associated with the RF signal. In some embodiments, prior to the adjusting, the phase shift corresponds to a time delay between the baseband signal and the RF signal. In some embodiments, offsetting the phase shift includes: offsetting, using a delay unit, the time delay between the baseband signal and the RF signal. In some embodiments, determining the first polar vector, the determining the second polar vector, the determining the phase shift, and the adjusting the RF signal, are performed iteratively until the phase shift satisfies a predetermined threshold. In some embodiments, the method further includes: receiving the first input signal prior to determining the first polar vector, wherein the first input signal comprises an in-phase / quadrature (IQ) input signal representing the AM component of the RF signal; and receiving the second input signal prior to determining the second polar vector, wherein the second input signal comprises an IQ input signal representing the PM component of the RF signal. In some embodiments, prior to adjusting, the method further includes: prior to the adjusting: applying, by the processor, to the first polar vector and the second polar vector, a frequency modulation (FM) dithering to offset an interference.

[0017] In an additional aspect of the disclosure, an apparatus includes a memory storing processor-readable code; and at least one processor coupled to the memory. The at least one processor is configured to execute the processor-readable code to cause the at least one processor to perform operations including: determining or receiving, based on a first input signal representing an amplitude modulation (AM) component of a radiofrequency (RF) signal, a first polar vector; determining or receiving, based on a second input signal representing a phase modulation (PM) component of the RF signal, a second polar vector, wherein the second polar vector is coaxially contra-rotated relative to the first polar vector; determining, based on the first polar vector and the second polar vector, a phase shift in the RF signal; and adjusting, based on the phase shift, the RF signal.

[0018] In an additional aspect of the disclosure, an apparatus includes: a memory storing processor-readable code; and at least one processor coupled to the memory, the at least one processor configured to execute the processor-readable code to cause the at least oneNRF Ref No. QLXX.P2142WO2406419W0 6 / 50processor to perform operations including: determining, based on a first polar vector representing an amplitude modulation (AM) component of an in-phase quadrature (IQ) signal and a second polar vector representing a phase modulation (PM) component of the IQ signal, a phase shift in the IQ signal, wherein the second polar vector is coaxially contra-rotated relative to the first polar vector; and adjusting, based on the phase shift, a radio frequency (RF) signal.

[0019] In an additional aspect of the disclosure, a transmitter device is disclosed that includes: a digital power amplifier configured to receive a first input signal representing an amplitude modulation (AM) component of a radiofrequency (RF) signal and a second input signal representing a phase modulation (PM) component of the RF signal; a memory storing processor-readable code; and at least one processor coupled to the memory. The at least one processor configured to execute the processor-readable code to cause the at least one processor to: determine or receive, based on the first input signal, a first polar vector; determine or receive, based on the second input signal, a second polar vector, wherein the second polar vector is coaxially contra-rotated relative to the first polar vector; determine, based on the first polar vector and the second polar vector, a phase shift in the RF signal; and adjust, based on the phase shift, the RF signal, wherein the adjustment reduces a time delay between the RF signal and a baseband signal associated with the RF signal.

[0020] In an additional aspect of the disclosure, a non-transitory computer-readable medium stores instructions that, when executed by a processor, cause the processor to perform operations. The operations include determining or receiving, by a processor, based on a first input signal representing an amplitude modulation (AM) component of a radiofrequency (RF) signal, a first polar vector; and determining or receiving, by the processor, based on a second input signal representing a phase modulation (PM) component of the RF signal, a second polar vector. The second polar vector is coaxially contra-rotated relative to the first polar vector. The method further includes: determining, by the processor, based on the first polar vector and the second polar vector, a phase shift in the RF signal; and adjusting, by the processor, based on the phase shift, the RF signal.

[0021] As used herein, a “radio frequency” signal is a signal having a frequency above baseband, which includes, in an example embodiment of a heterodyne receiver, intermediate frequency signals.

[0022] As used herein, an “intermediate frequency” signal is a RF signal that has been downconverted from another RF signal to a frequency that is above baseband, such as inNRF Ref No. QLXX.P2142WO2406419W0 7 / 50an example embodiment of a heterodyne mmWave transceiver that receives a mmWave RF signal and downconverts the mmWave RF signal to a mmWave IF signal that is further processed, such as through further downconversion, to a lower frequency RF signal or a baseband signal.

[0023] The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purposes of illustration and description, and not as a definition of the limits of the claims.

[0024] While aspects and implementations are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, aspects and / or uses may come about via integrated chip implementations and other nonmodule-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchasing devices, medical devices, artificial intelligence (Al)-enabled devices, etc.). While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range in spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described aspects. For example, transmission and reception of wireless signals necessarily includes a number ofNRF Ref No. QLXX.P2142WO2406419W0 8 / 50components for analog and digital purposes (e.g., hardware components including antenna, radio frequency (RF)-chains, power amplifiers, modulators, buffer, processor(s), interleaver, adders / summers, etc.). It is intended that innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes, and constitution.BRIEF DESCRIPTION OF THE DRAWINGS

[0025] A further understanding of the nature and advantages of the present disclosure may be realized by reference to the following drawings. In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

[0026] Figure 1 is a block diagram illustrating details of an example wireless communication system according to one or more aspects of the present disclosure.

[0027] Figure 2 is a block diagram illustrating examples of a base station and a user equipment (UE) according to one or more aspects of the present disclosure.

[0028] Figure 3 is a block diagram illustrating an example device for improving time alignment in polar transmission according to one or more aspects of the present disclosure.

[0029] Figure 4 is a block diagram illustrating the use of input signals in a device for improving time misalignment in polar transmission according to one or more aspects of the present disclosure.

[0030] Figure 5 is a schematic diagram illustrating a phase shift in a polar transmission based on polar vectors according to one or more aspects of the present disclosure.

[0031] Figure 6 is a flow diagram of an example process for improving time alignment in polar transmission according to one or more aspects of the present disclosure.

[0032] Figure 7 is a flow diagram of another example process for improving time alignment in polar transmission according to one or more aspects of the present disclosure.

[0033] Like reference numbers and designations in the various drawings indicate like elements.DETAILED DESCRIPTIONNRF Ref No. QLXX.P2142WO2406419W0 9 / 50

[0034] The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to limit the scope of the disclosure. Rather, the detailed description includes specific details for the purpose of providing a thorough understanding of the inventive subject matter. It will be apparent to those skilled in the art that these specific details are not required in every case and that, in some instances, well-known structures and components are shown in block diagram form for clarity of presentation.

[0035] The present disclosure provides systems, devices, apparatuses, methods, and computer- readable media that support image processing, including techniques for improving time alignment in polar transmitters. Such systems, devices, apparatuses, methods, and computer-readable media may rely on polar vectors that are determined based on input signals received by a digital power amplifier. The input signals may include a first input signal representing (e.g., transferring information for) an amplitude modulation (AM) component of a radiofrequency (RF) signal and a second input signal representing (e.g., transferring information for) the phase modulation (PM) component of the RF signal. The polar vectors may include: a first polar vector determined based on the first input signal representing the AM component of the RF signal, and a second polar vector determined based on the second signal representing the PM component but coaxially contra-rotated relative to the first polar vector. The first and second input signals, representing the AM and PM components, may each have an in-phase (I) and quadrature (Q) value. For example, the first input signal may have IQ values (“IQ data”) separate from those of the second input signal. Thus, each of the AM and PM components of the RF signal may be expressed in Cartesian form (e.g., the IQ values representable on an X-Y axis). As used herein, a polar vector includes a magnitude component (r) and an angle component (9). The first and second polar vectors may be determined by using the magnitude component (r) to indicate the amplitude information represented by the first and second input signals and using the angle component (9) to indicate the phase information represented by the first and second input signals, respectively. However, by coaxially contrarotating the second polar vector, the angle may be in an opposite rotational direction from that of the first polar vector but may be rotated to a degree or radian that is still commensurate and / or proportionate to the phase of the second input signal.

[0036] A phase shift in the signal may be determined based on the first polar vector and the second polar vector. For example, the phase shift may be determined via a product of theNRF Ref No. QLXX.P2142WO2406419W0 10 / 50polar vectors, such that the phase shift is a difference in the phases encoded by the IQ data of each of the AM and PM components (e.g., based on a summation of the positive and negative angular values of the polar vectors, as the second polar vector is coaxially contra-rotated relative to the first polar vector). The phase shift may be correlated to a time misalignment in the RF signal. The time misalignment may be based on a time delay between the first input signal and the second input signal. Also or alternatively, the time misalignment may be based on a time delay between the RF signal and a baseband signal associated with the RF signal. The time delay may be used to adjust the RF signal to correct the time misalignment.

[0037] In some embodiments, the digital power amplifier (e.g., a switched capacitor power amplifier (SCPA) or, more generally, a radio frequency digital-to-analog-converter (RFDAC)) may be configured to operate in both polar mode (e.g., to facilitate polar modulation) and Cartesian mode (e.g., to receive inputs for the quadrature modulation (e.g., in-phase (I) and quadrature (Q) inputs)). Furthermore, the systems, devices, apparatuses, methods, and computer-readable media may rely on or include one or more delay units. For example, the RF signal may be adjusted by using the one or more delay units to offset the time delay between a baseband signal and the RF signal. Based on the adjustment, a different and / or an adjusted set of input signals may be received by the digital power amplifier (e.g., based on an adjusted AM component and / or PM component of the RF signal), and the a forementioned steps may be repeated until any time misalignment, as measured by the phase shift, is within a tolerance level. In some embodiments, the devices and apparatuses may use a loopback circuit to measure the phase shift to monitor corrections for time misalignment. Devices operated according to a portion of this application may provide improved timing, which results in higher throughput for the device and a better, faster experience for the user when accessing data over a wireless network.

[0038] Particular implementations of the subject matter described in this disclosure may be implemented to realize one or more of the following potential advantages or benefits. In some aspects, the present disclosure provides techniques for improving time alignment in polar transmitters and other devices incorporating polar modulation. By ensuring time alignment and / or reducing time misalignment, the present disclosure improves the RF signal quality and transmitter quality (e.g., based on error vector magnitude). Furthermore, the techniques described in the present disclosure allow polar transmittersNRF Ref No. QLXX.P2142WO2406419W0 11 / 50to be implemented in wireless networks at scale, thereby reducing power inefficiencies typically associated with wireless communications.

[0039] In various implementations, the techniques and apparatus may be used for wireless communication networks such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, 5thGeneration (5G) or new radio (NR) networks (sometimes referred to as “5GNR” networks, systems, or devices), as well as other communications networks. As described herein, the terms “networks” and “systems” may be used interchangeably.

[0040] A CDMA network, for example, may implement a radio technology such as universal terrestrial radio access (UTRA), cdma2000, and the like. UTRA includes wideband- CDMA (W-CDMA) and low chip rate (LCR). CDMA2000 covers IS-2000, IS-95, and IS-856 standards.

[0041] A TDMA network may, for example implement a radio technology such as Global System for Mobile Communication (GSM). The 3rd Generation Partnership Project (3GPP) defines standards for the GSM EDGE (enhanced data rates for GSM evolution) radio access network (RAN), also denoted as GERAN. GERAN is the radio component of GSM / EDGE, together with the network that joins the base stations (for example, the Ater and Abis interfaces) and the base station controllers (A interfaces, etc.). The radio access network represents a component of a GSM network, through which phone calls and packet data are routed from and to the public switched telephone network (PSTN) and Internet to and from subscriber handsets, also known as user terminals or user equipments (UEs). A mobile phone operator's network may comprise one or more GERANs, which may be coupled with UTRANs in the case of a UMTS / GSM network. Additionally, an operator network may also include one or more LTE networks, or one or more other networks. The various different network types may use different radio access technologies (RATs) and RANs.

[0042] An OFDMA network may implement a radio technology such as evolved UTRA (E- UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and the like. UTRA, E-UTRA, and GSM are part of universal mobile telecommunication system (UMTS). In particular, long-term evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE areNRF Ref No. QLXX.P2142WO2406419W0 12 / 50described in documents provided from an organization named “3rd Generation Partnership Project” (3 GPP), and cdma2000 is described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). These various radio technologies and standards are known or are being developed. For example, the 3GPP is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (3G) mobile phone specification. 3GPP LTE is a 3 GPP project which was aimed at improving UMTS mobile phone standard. The 3 GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices. The present disclosure may describe certain aspects with reference to LTE, 4G, or 5G NR technologies; however, the description is not intended to be limited to a specific technology or application, and one or more aspects described with reference to one technology may be understood to be applicable to another technology. Additionally, one or more aspects of the present disclosure may be related to shared access to wireless spectrum between networks using different radio access technologies or radio air interfaces.

[0043] 5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. To achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for 5G NR networks. The 5G NR will be capable of scaling to provide coverage (1) to a massive Internet of things (loTs) with an ultra-high density (e.g., ~1 M nodes / km ), ultra-low complexity (e.g., -10 s of bits / sec), ultra-low energy (e.g., -10+ years of battery life), and deep coverage with the capability to reach challenging locations; (2) including mission-critical control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., -99.9999% reliability), ultra-low latency (e.g., - 1 millisecond (ms)), and users with wide ranges of mobility or lack thereof; and (3) with enhanced mobile broadband including extreme high capacity (e.g., - 10 Tbps / km ), extreme data rates (e.g., multi - Gbps rate, 100+ Mbps user experienced rates), and deep awareness with advanced discovery and optimizations.

[0044] Devices, networks, and systems may be configured to communicate via one or more portions of the electromagnetic spectrum. The electromagnetic spectrum is often subdivided, based on frequency or wavelength, into various classes, bands, channels, etc. In 5G NR two initial operating bands have been identified as frequency rangeNRF Ref No. QLXX.P2142WO2406419W0 13 / 50designations FR1 (410 MHz - 7.125 GHz) and FR2 (24.25 GHz - 52.6 GHz). The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” (mmWave) band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz - 300 GHz) which is identified by the International Telecommunications Union (ITU) as a “mmWave” band.

[0045] With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “mmWave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, or may be within the EHF band.

[0046] 5G NR devices, networks, and systems may be implemented to use optimized OFDMbased waveform features. These features may include scalable numerology and transmission time intervals (TTIs); a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD) design or frequency division duplex (FDD) design; and advanced wireless technologies, such as massive multiple input, multiple output (MIMO), robust mmWave transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in 5G NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of less than 3 GHz FDD or TDD implementations, subcarrier spacing may occur with 15 kHz, for example over 1, 5, 10, 20 MHz, and the like bandwidth. For other various outdoor and small cell coverage deployments of TDD greater than 3 GHz, subcarrier spacing may occur with 30 kHz over 80 / 100 MHz bandwidth. For other various indoor wideband implementations, using a TDD over the unlicensed portion of the 5 GHz band, the subcarrier spacing may occur with 60 kHz over a 160 MHz bandwidth. Finally, for various deployments transmitting with mmWave components at a TDD of 28 GHz, subcarrier spacing may occur with 120 kHz over a 500 MHz bandwidth.NRF Ref No. QLXX.P2142WO2406419W0 14 / 50

[0047] The scalable numerology of 5G NR facilitates scalable TTI for diverse latency and quality of service (QoS) requirements. For example, shorter TTI may be used for low latency and high reliability, while longer TTI may be used for higher spectral efficiency. The efficient multiplexing of long and short TTIs to allow transmissions to start on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe design with uplink or downlink scheduling information, data, and acknowledgement in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive uplink or downlink that may be flexibly configured on a per-cell basis to dynamically switch between uplink and downlink to meet the current traffic needs.

[0048] For clarity, certain aspects of the apparatus and techniques may be described below with reference to example 5G NR implementations or in a 5G-centric way, and 5G terminology may be used as illustrative examples in portions of the description below; however, the description is not intended to be limited to 5G applications.

[0049] Moreover, it should be understood that, in operation, wireless communication networks adapted according to the concepts herein may operate with any combination of licensed or unlicensed spectrum depending on loading and availability. Accordingly, it will be apparent to a person having ordinary skill in the art that the systems, apparatus and methods described herein may be applied to other communications systems and applications than the particular examples provided.

[0050] While aspects and implementations are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, implementations or uses may come about via integrated chip implementations or other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail devices or purchasing devices, medical devices, AI- enabled devices, etc.). While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range from chip-level or modular components to non- modular, non-chip-level implementations and further to aggregated, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or moreNRF Ref No. QLXX.P2142WO2406419W0 15 / 50described aspects. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described aspects. It is intended that innovations described herein may be practiced in a wide variety of implementations, including both large devices or small devices, chip-level components, multi-component systems (e.g., radio frequency (RF)-chain, communication interface, processor), distributed arrangements, end-user devices, etc. of varying sizes, shapes, and constitution.

[0051] FIG. 1 is a block diagram illustrating details of an example wireless communication system according to one or more aspects. The wireless communication system may include wireless network 100. Wireless network 100 may, for example, include a 5G wireless network. As appreciated by those skilled in the art, components appearing in FIG. 1 are likely to have related counterparts in other network arrangements including, for example, cellular- style network arrangements and non-cellular-style-network arrangements (e.g., device to device or peer to peer or ad hoc network arrangements, etc.).

[0052] Wireless network 100 illustrated in FIG. 1 includes a number of base stations 105 and other network entities. A base station may be a station that communicates with the UEs and may also be referred to as an evolved node B (eNB), a next generation eNB (gNB), an access point, and the like. Each base station 105 may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” may refer to this particular geographic coverage area of a base station or a base station subsystem serving the coverage area, depending on the context in which the term is used. In implementations of wireless network 100 herein, base stations 105 may be associated with a same operator or different operators (e.g., wireless network 100 may include a plurality of operator wireless networks). Additionally, in implementations of wireless network 100 herein, base station 105 may provide wireless communications using one or more of the same frequencies (e.g., one or more frequency bands in licensed spectrum, unlicensed spectrum, or a combination thereof) as a neighboring cell. In some examples, an individual base station 105 or UE 115 may be operated by more than one network operating entity. In some other examples, each base station 105 and UE 115 may be operated by a single network operating entity.

[0053] A base station may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, or other types of cell. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allowNRF Ref No. QLXX.P2142WO2406419W0 16 / 50unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a pico cell, would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a femto cell, would also generally cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in the home, and the like). A base station for a macro cell may be referred to as a macro base station. A base station for a small cell may be referred to as a small cell base station, a pico base station, a femto base station or a home base station. In the example shown in FIG. 1, base stations 105d and 105e are regular macro base stations, while base stations 105a- 105c are macro base stations enabled with one of 3 dimension (3D), full dimension (FD), or massive MIMO. Base stations 105a-105c take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. Base station 105f is a small cell base station which may be a home node or portable access point. A base station may support one or multiple (e.g., two, three, four, and the like) cells.

[0054] Wireless network 100 may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. In some scenarios, networks may be enabled or configured to handle dynamic switching between synchronous or asynchronous operations.

[0055] UEs 115 are dispersed throughout the wireless network 100, and each UE may be stationary or mobile. It should be appreciated that, although a mobile apparatus is commonly referred to as a UE in standards and specifications promulgated by the 3 GPP, such apparatus may additionally or otherwise be referred to by those skilled in the art as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, a gaming device, an augmented reality device, vehicular component, vehicularNRF Ref No. QLXX.P2142WO2406419W0 17 / 50device, or vehicular module, or some other suitable terminology. Within the present document, a “mobile” apparatus or UE need not necessarily have a capability to move, and may be stationary. Some non-limiting examples of a mobile apparatus, such as may include implementations of one or more of UEs 115, include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a laptop, a personal computer (PC), a notebook, a netbook, a smart book, a tablet, and a personal digital assistant (PDA). A mobile apparatus may additionally be an loT or “Internet of everything” (loE) device such as an automotive or other transportation vehicle, a satellite radio, a global positioning system (GPS) device, a global navigation satellite system (GNSS) device, a logistics controller, a drone, a multi-copter, a quad-copter, a smart energy or security device, a solar panel or solar array, municipal lighting, water, or other infrastructure; industrial automation and enterprise devices; consumer and wearable devices, such as eyewear, a wearable camera, a smart watch, a health or fitness tracker, a mammal implantable device, gesture tracking device, medical device, a digital audio player (e.g., MP3 player), a camera, a game console, etc.; and digital home or smart home devices such as a home audio, video, and multimedia device, an appliance, a sensor, a vending machine, intelligent lighting, a home security system, a smart meter, etc. In one aspect, a UE may be a device that includes a Universal Integrated Circuit Card (UICC). In another aspect, a UE may be a device that does not include a UICC. In some aspects, UEs that do not include UICCs may also be referred to as loE devices. UEs 115a-l 15d of the implementation illustrated in FIG. 1 are examples of mobile smart phone-type devices accessing wireless network 100. A UE may also be a machine specifically configured for connected communication, including machine type communication (MTC), enhanced MTC (eMTC), narrowband loT (NB-IoT) and the like. UEs 115e-l 15k illustrated in FIG. 1 are examples of various machines configured for communication that access wireless network 100.

[0056] A mobile apparatus, such as UEs 115, may be able to communicate with any type of the base stations, whether macro base stations, pico base stations, femto base stations, relays, and the like. In FIG. 1, a communication link (represented as a lightning bolt) indicates wireless transmissions between a UE and a serving base station, which is a base station designated to serve the UE on the downlink or uplink, or desired transmission between base stations, and backhaul transmissions between base stations. UEs may operate as base stations or other network nodes in some scenarios. Backhaul communicationNRF Ref No. QLXX.P2142WO2406419W0 18 / 50between base stations of wireless network 100 may occur using wired or wireless communication links.

[0057] In operation at wireless network 100, base stations 105a-105c serve UEs 115a and 115b using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. Macro base station 105d performs backhaul communications with base stations 105a- 105c, as well as small cell, base station 105f. Macro base station 105d also transmits multicast services which are subscribed to and received by UEs 115c and 115d. Such multicast services may include mobile television or stream video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or gray alerts.

[0058] Wireless network 100 of implementations supports mission critical communications with ultra-reliable and redundant links for mission critical devices, such UE 115e, which is a drone. Redundant communication links with UE 115e include from macro base stations 105d and 105e, as well as small cell base station 105f. Other machine type devices, such as UE 115f (thermometer), UE 115g (smart meter), and UE 115h (wearable device) may communicate through wireless network 100 either directly with base stations, such as small cell base station 105f, and macro base station 105e, or in multi-hop configurations by communicating with another user device which relays its information to the network, such as UE 115f communicating temperature measurement information to the smart meter, UE 115g, which is then reported to the network through small cell base station 105f. Wireless network 100 may also provide additional network efficiency through dynamic, low-latency TDD communications or low-latency FDD communications, such as in a vehicle-to-vehicle (V2V) mesh network between UEs 115i-l 15k communicating with macro base station 105e. Furthermore, the use of improved polar transmitters, such as those described herein, may further improve wireless networks, for example, by increasing power efficiency and signal quality of wireless communications.

[0059] FIG. 2 is a block diagram illustrating examples of base station 105 and UE 115 according to one or more aspects. Base station 105 and UE 115 may be any of the base stations and one of the UEs in FIG. 1. For a restricted association scenario (as mentioned above), base station 105 may be small cell base station 105f in FIG. 1, and UE 115 may be UE 115c or 115d operating in a service area of base station 105f, which in order to access small cell base station 105f, would be included in a list of accessible UEs for small cell base station 105f. Base station 105 may also be a base station of some other type. As shownNRF Ref No. QLXX.P2142WO2406419W0 19 / 50in FIG. 2, base station 105 may be equipped with antennas 234a through 234t, and UE 115 may be equipped with antennas 252a through 252r for facilitating wireless communications.

[0060] At base station 105, transmit processor 220 may receive data from data source 212 and control information from controller 240, such as a processor. The control information may be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid-ARQ (automatic repeat request) indicator channel (PHICH), a physical downlink control channel (PDCCH), an enhanced physical downlink control channel (EPDCCH), an MTC physical downlink control channel (MPDCCH), etc. The data may be for a physical downlink shared channel (PDSCH), etc. Additionally, transmit processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Transmit processor 220 may also generate reference symbols, e.g., for the primary synchronization signal (PSS) and secondary synchronization signal (SSS), and cell-specific reference signal. Transmit (TX) MIMO processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, or the reference symbols, if applicable, and may provide output symbol streams to modulators (MODs) 232a through 232t. For example, spatial processing performed on the data symbols, the control symbols, or the reference symbols may include precoding. In some embodiments, one or more of the aforementioned transmit processors (e.g., Transmit processor 220, TX MIMO processor 230, etc.) may include a polar transmitter and / or may rely on polar transmission. Furthermore, the polar transmitter and / or polar transmission may include improved time alignment using techniques described herein. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may additionally or alternatively process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 232a through 232t may be transmitted via antennas 234a through 234t, respectively. In some embodiments, the modulators 232A-232t may use polar modulation, based on techniques for improving time alignment of polar modulation as described herein.

[0061] At UE 115, antennas 252a through 252r may receive the downlink signals from base station 105 and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify,NRF Ref No. QLXX.P2142WO2406419W0 20 / 50downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 may obtain received symbols from demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. Receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 115 to data sink 260, and provide decoded control information to controller 280, such as a processor.

[0062] On the uplink, at UE 115, transmit processor 264 may receive and process data (e.g., for a physical uplink shared channel (PUSCH)) from data source 262 and control information (e.g., for a physical uplink control channel (PUCCH)) from controller 280. Additionally, transmit processor 264 may also generate reference symbols for a reference signal. The symbols from transmit processor 264 may be precoded by TX MIMO processor 266 if applicable, further processed by modulators 254a through 254r (e.g., for SC-FDM, etc.), and transmitted to base station 105. At base station 105, the uplink signals from UE 115 may be received by antennas 234, processed by demodulators 232, detected by MIMO detector 236 if applicable, and further processed by receive processor 238 to obtain decoded data and control information sent by UE 115. Receive processor 238 may provide the decoded data to data sink 239 and the decoded control information to controller 240.

[0063] Controllers 240 and 280 may direct the operation at base station 105 and UE 115, respectively. Controller 240 or other processors and modules at base station 105 or controller 280 or other processors and modules at UE 115 may perform or direct the execution of various processes for the techniques described herein, such as to perform or direct the execution illustrated in FIG. 5 or FIG. 6, or other processes for the techniques described herein. Memories 242 and 282 may store data and program codes for base station 105 and UE 115, respectively. Scheduler 244 may schedule UEs for data transmission on the downlink or the uplink.

[0064] In some cases, UE 115 and base station 105 may operate in a shared radio frequency spectrum band, which may include licensed or unlicensed (e.g., contention-based) frequency spectrum. In an unlicensed frequency portion of the shared radio frequency spectrum band, UEs 115 or base stations 105 may traditionally perform a medium-sensing procedure to contend for access to the frequency spectrum. For example, UE 115 or base station 105 may perform a listen-before-talk or listen-before-transmitting (LBT)NRF Ref No. QLXX.P2142WO2406419W0 21 / 50procedure such as a clear channel assessment (CCA) prior to communicating in order to determine whether the shared channel is available. In some implementations, a CCA may include an energy detection procedure to determine whether there are any other active transmissions. For example, a device may infer that a change in a received signal strength indicator (RSSI) of a power meter indicates that a channel is occupied. Specifically, signal power that is concentrated in a certain bandwidth and exceeds a predetermined noise floor may indicate another wireless transmitter. A CCA also may include detection of specific sequences that indicate use of the channel. For example, another device may transmit a specific preamble prior to transmitting a data sequence. In some cases, an LBT procedure may include a wireless node adjusting its own backoff window based on the amount of energy detected on a channel or the acknowledge / negative-acknowledge (ACK / NACK) feedback for its own transmitted packets as a proxy for collisions.

[0065] Figure 3 is a block diagram illustrating an example device 300 for improving time alignment in polar transmission according to one or more aspects. In some embodiments, the device 300 may include or may be part of a polar radio frequency (RF) transceiver, such as a converged sub-6 Ghz and mmWave radio frequency (RF) transceiver, a sub-6 GHz radio frequency (RF) transceiver, or a mmWave radio frequency (RF) transceiver. In some embodiments, portions or all of the device 300 of FIG. 3 may be located in a single integrated circuit (IC) sharing a common substrate. The device 300 may include a hybrid phase module 310 configured to generate digital input signals carrying in-phase (I) and quadrature (Q) information. In some embodiments, the device 300 may include a RF front-end (RFFE), which may include duplexers, SAW filters, switches, LNAs, and / or other transmit or receive circuits for conditioning signals received from an antenna (e.g., such as but not limited to antenna 312 or another antenna). For example, the device 300 may include an antenna 312, to transmit or receive radio frequency (RF) signals, including polar RF signals transmitted by the device 300. In some embodiments, the device 300 may include separate circuits for conditioning or otherwise processing signals.

[0066] The output of the hybrid phase module 310 may include input signals for the digital power amplifier 320 and / or the phase modulator 330. Such input signals generated by the hybrid phase module 310 for inputting to the digital power amplifier 320 and / or the phase modulator 330 may be In-phase / Quadrature (IQ) signals that are digital, but which may based on or represent properties of RF and / or baseband signal. The input signals may include a first input signal carrying amplitude modulation information of the RF signal.NRF Ref No. QLXX.P2142WO2406419W0 22 / 50The input signals may further include a second input signal carrying phase modulation (PM) information of the RF signal. In some embodiments, the second input signal may be further processed at a phase modulator 330 so that the second input signal carries the PM information. In some embodiments, the input signals (e.g., first input signal, second input signal, phase modulated input signal, etc.) may be digital input signals received by the digital power amplifier 320. Alternatively, such input signals may be radio frequency signals (e.g., baseband (BB) RF signals).

[0067] The phase modulator 330 (e.g., a wideband phase modulator) may include one or more a digital-to-analog converters (DAC) 332, baseband filters (BBFs) 334, mixer 336, and / or limiters 338. For example, in at least one embodiment, the phase modulator 330 may include a DAC and a baseband filter for each of the I and Q components of the incoming second input signal received by the phase modulator 330, one or more mixers 336 and a limiter 338 for each of the I and Q components of the outgoing second input signal from the phase modulator 330. In some embodiments, the phase modulator 330 may be used to modulate a phase for the second input signal based on PM information of the RF signal.

[0068] The hybrid phase module 310 may be coupled to a digital power amplifier 320, such as a switched capacitor power amplifier (SCPA). The digital power amplifier 320 may be configured to receive the input signals from the hybrid phase module 310 and / or the phase modulator 330 and determine polar signals based on polar vectors for transmission. Furthermore, the digital power amplifier 320 may be configured to modulate the polar signals using a voltage supply based on amplitude and phase information. Thus, the digital power amplifier 320 may be configured to operate in both polar mode (e.g., to facilitate polar modulation for transmission) and Cartesian mode (e.g., to receive inputs for quadrature modulation (e.g., in-phase (I) and quadrature (Q) inputs)). In some embodiments, the digital power amplifier 320 is shared on an IC with one or more of the hybrid phase module 310, antenna 312, and / or the phase modulator 330.

[0069] As discussed below, the digital power amplifier 320 may be used to determine a phase shift based on the first input signal (e.g., carrying the AM information of the RF signal and represented as a digital IQ signal) and the second input signal (e.g., carrying the PM information of the RF signal and represented as a digital IQ signal). In some embodiments, the digital power amplifier 320 may rely on the controller 370 to perform these determinations based on instructions stored in the memory 360. In particular, the digital power amplifier 320 may determine or receive a first polar vector based on theNRF Ref No. QLXX.P2142WO2406419W0 23 / 50first input signal representing the AM component of the RF signal (and represented as a digital IQ signal), and a second polar vector based on the second input signal representing the PM component but coaxially contra-rotated relative to the first polar vector. For example, the magnitude component (r) of the first and second polar vectors may indicate the amplitude information represented by the first and second input signals, respectively, and the angle component (9) of the first and second polar vectors may indicate the phase information represented by the first and second input signals, respectively. The second polar vector may be coaxially contra-rotated relative to the first polar vector such that the angle representing the phase in the second input signal may rotate to a degree or radian that is still commensurate and / or proportionate to the phase of the second input signal but in an opposite direction from the angle of the first polar vector.

[0070] In some embodiments, the first input signal may be applied to the amplitude modulation (AM) path of an IQ signal of the digital power amplifier 320, whereas the second input signal may be applied to a phase modulated (PM) path of an IQ signal of the digital power amplifier 320. The first input signal may (e.g., in the absence of the second input signal) cause the outputted signal of the digital power amplifier 320 to rotate (e.g., by phase) in a first direction (e.g., relative to a unmodulated or minimally modulated phase of a low oscillator (e.g., oscillator 340)). The second input signal may (e.g., in the absence of the first input signal) cause the outputted signal of the digital power amplifier 320 to rotate in a second direction (e.g., relative to the unmodulated or minimally modulated phase of the low oscillator (e.g., oscillator 340)). For example, the first direction may be a counterclockwise direction of the phase, as represented in a first polar vector corresponding to the first input signal, whereas the second direction may be a clockwise direction of the phase, as represented in a second polar vector corresponding to the second input signal. In some embodiments, the outputted signal of the digital power amplifier may be a radio frequency continuous wave (RF CW).

[0071] In some embodiments, the digital power amplifier 320 may be used to determine a phase shift in the received signal based on the first polar vector and the second polar vector. As will be discussed herein, fluctuations in process, voltage, and / or temperature within a polar transmitter may cause unintended shifts in phase, for example, in the first input signal and / or the second input signal. The phase shift may cause a time misalignment in the input signals, thus affecting the quality of the polar transmission. The phase shift may be determined via a product of the polar vectors, such that the phase shift is a differenceNRF Ref No. QLXX.P2142WO2406419W0 24 / 50in the phases encoded by the IQ data of each of the AM and PM components (e.g., based on a summation of the positive and negative angular values of the polar vectors, as the second polar vector is coaxially contra-rotated relative to the first polar vector). Thus, in at least one embodiment, the phase shift may be based on an output of the digital power amplifier that is an RF CW. Absent any delay in the PM path, the output RF CW signal from the digital power amplifier 320 may not be rotated by phase relative to the phase of the low oscillator (e.g., oscillator 340). For example, the outputted RF CW signal may be based on a cancellation of the first component of the output signal that is rotated in a first direction (e.g., based on the first input signal) and a second component of the output signal that is rotated in the second direction (e.g., based on the second input signal).

[0072] For example, the digital power amplifier 320 may output a signal based on the product of the first polar vector and the second polar vector (e.g., for transmission via antenna 312). The signal may be measured, for example, by a loopback circuit 350. For example, the outputted signal of the digital power amplifier 320 may be downconverted by the loopback circuit 350, resulting in an IQ signal (e.g., IQ direct current (IQ DC)). In some embodiments, the loopback circuit 350 may include a measurement probe to analyze or measure a specimen of the signal outputted by the digital power amplifier 320 and / or the antenna 312. If there is no phase shift (e.g., no time misalignment), the angular components of the polar vectors may cancel out to zero. However, if there is a phase shift or, if the phase shift is above a predetermined threshold, the device 300 may facilitate the adjustment of the IQ signals (or of the original RF and / or baseband signal on which the IQ signals are based) to offset the phase shift and thereby improve time alignment.

[0073] In some embodiments, the device may offset the phase shift by adjusting the phase of one or both of the first input signal and the second input signal via delay units 390 A and 390B respectively. Each delay unit 390A-390B may comprise a hardware configured to provide a specific time delay. The specific time delay may be correlated to the phase shift, as determined by the product of the polar vectors. In some embodiments, phase shifts may be mapped to time delays based on a lookup table 362 stored in the memory 360. Also or alternatively, the device 300 may adjust the RF signal (on which the IQ signals are based) by causing an oscillator 340 to reconfigure the phase of the second input signal to offset the phase shift. The oscillator 340 (e.g., low oscillator) may be a hardware used by the phase modulator 330 to modulate the second input signal to carry a desired phase information, such as that extracted from an RF signals (or from the IQ signals based onNRF Ref No. QLXX.P2142WO2406419W0 25 / 50the RF signals). In some embodiments, the oscillator 340 may be a low oscillator that may remain unmodulated or have low or minimal oscillation, relative to outputs of the digital power amplifier 320.

[0074] In some embodiments, the device 300 may be configured to detect interferences in signal transmission and calibrate for the interferences while improving the time alignment for the input signals. For example, an interference in signal transmission (e.g., a known noise signal) may be detected via the antenna 312. The digital power amplifier 320 may apply a frequency modulation (FM) dithering to the output polar vectors (e.g., the first polar vector and the second polar vector) based on the interference. The product of the polar vector may thus account for the FM dithering as well (e.g., when summing the angular components). When adjusting for the phase shift, the device 300 may further adjust the input signals by removing (e.g., cancelling out) the FM dithering using a baseband signal (e.g., via the oscillator 340).

[0075] The device 300 may further include a memory 360 and a controller 370. In some embodiments, the memory may store or include a lookup table 362 that stores information mapping a phase shift to a time delay. For example, the phase shift may be mapped to time delay based on historical data. Also or alternatively, the phase shift may be mapped to a time delay using a computation based on a correlation or linear relationship.

[0076] In some embodiments, the memory 360 may include a computer readable storage medium. Such computer-readable storage media may include, but are not limited to, random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium capable of storing instructions for execution by the controller 370. For example, the memory 360 may store instructions that, when executed by the controller 370, may cause the controller 370 to perform one or more processes described herein. Such processes may include determining polar vectors based on the received inputs by the digital power amplifier 320, receiving a phase shift (e.g., measured via the loopback circuit 350), and / or determining a time delay based on a phase shift. In some embodiments, the memory 360 may store data obtained from other components of the device 300, for example, IQ data from the first input signal and IQ data from the second input signal, allowing the controller 370 to determine polar vectorsNRF Ref No. QLXX.P2142WO2406419W0 26 / 50for the digital power amplifier 320. Furthermore, the memory 360 may store a look-up table that allows the controller 370 to map the phase shift (determined via the loopback circuit 350) to a time delay. In some embodiments, the controller 370 may use the time delay to cause delay unit 390A and / or delay unit 390B to align the time of the respective input signals (e.g., thereby offsetting the phase shift). In some embodiments, the controller 370 may be a processor configured to execute processor readable instructions stored in the memory 360 for performing one or more processes described herein.

[0077] In some embodiments, the time delay may be determined based on two or more phase shifts respectively determined from two or more sets of first and second input signals. For example, the first set may be based on a first input signal being applied to the AM path of an IQ signal of the digital power amplifier 320 having a first frequency, and the second input signal being applied to the PM path of the IQ signal having the first frequency, of which each of the first and second input signals may (e.g., in the absence of the other input signals) be coaxially contra-rotated (e.g., relative to a unmodulated or minimally modulated phase of a low oscillator (e.g., oscillator 340)), such that the phases are in opposite directions when represented as polar vectors. The outputted RF CW signal of the digital power amplifier, which may reflect a product of these components, may be downcoverted by the loopback circuit 350 to determine a phase shift as previously discussed. The aforementioned phase shift may thus be a first phase shift representing the first set of the two or more sets.

[0078] However, the aforementioned process may be repeated again based on a subsequent IQ signal of the digital power amplifier 320 having a second frequency. Thus, the second set may be based on another first input signal being applied to the AM path of an IQ signal of the digital power amplifier 320 having the second frequency, and another second input signal being applied to the PM path of the IQ signal having the second frequency. As before, each of the first and second input signals may (e.g., in the absence of the other input signals) be coaxially contra-rotated (e.g., relative to a unmodulated or minimally modulated phase of a low oscillator), such that the phases are in opposite directions when represented as polar vectors. The subsequently outputted RF CW signal of the digital power amplifier in the second set may be downcoverted by the loopback circuit 350 to determine a second phase shift.

[0079] A processor or controller (e.g., controller 370) may use the first and second phase shifts (Phasei and Phase?, respectively) and the first and second frequencies (Freqi and Freq?,NRF Ref No. QLXX.P2142WO2406419W0 27 / 50respectively) to determine a group delay (GD), for example, via the expression: GD = §rouP delay (GD) value may be used to compensate and / orotherwise adjust a delay in the PM path of the device 300 and / or otherwise align the PM and AM paths of the device 300.

[0080] FIG. 4 is a block diagram illustrating the use of input signals in a device 400 for improving time misalignment in polar transmission according to one or more aspects of the present disclosure. As shown in FIG. 4, the device 400 (e.g., such as but not limited to device 300), may include a digital power amplifier 440 comprising a set of two switched capacitor power amplifiers (SCPAs) 450A and 450B to receive two input signals (first input signal and second input signal) for outputting a RF signal, and each input signal may include IQ data. The digital power amplifier 440 may be an example of the digital power amplifier 320 of FIG. 3. The first input signal may represent (e.g., carry) the amplitude information of an RF or baseband signal (e.g., on which an IQ signal received by the hybrid phase module 310 may be based). The first input signal may itself also exhibit or otherwise represent a phase 410. The second input signal may represent (e.g., carry) the phase information of the RF signal (e.g., on which an IQ signal received by the hybrid phase module 310 may be based). In some embodiments, the phase modulation (PM) information of the RF signal may be transferred to the second input signal via a phase modulator 330 and / or oscillator 340, based on the phase modulation of the RF signal. The second input signal may thus exhibit or otherwise represent a phase 420. As shown in FIG. 4, a first SCPA 450A may receive the in-phase (I) components of the first and second input signals, while the second SCPA 450B may receive the quadrature (Q) components of the first and second input signals. The digital power amplifier comprising the SCPA 450A and 450B may be configured to determine polar vectors (a first polar vector and a second polar vector) based on the received input signals (first input signal and second input signa.)

[0081] For example, in at least one embodiment, the first polar vector may be determined by expressing the received information as M, where co is an angular value representing the phase 410 of the first input signal, M is the magnitude value for the polar vector representing the amplitude for the first input signal, and t is the time. The second polar vector may be determined by expressing the received information as N * exp_i“t+i“Iot+<p, where co is an angular value for the polar vector representing the phase 420 of the second input signal, )_lo is an angular value representing a phaseNRF Ref No. QLXX.P2142WO2406419W0 28 / 50associated with the oscillator 340, as written in the polar vector, N is the amplitude for the polar vector, t is the time, and <p is any phase shift, which may result from a time misalignment. As previously discussed, the digital power amplifier 440 may determine a polar signal based on a product of the first polar vector and the second polar vector, such that the polar vector is coaxially contra-rotated relative to the first polar vector. The product determination may be facilitated via logic gate 430. Thus, in at least one embodiment, the resulting product may be expressed as M * expi6)t* N *

[0082] The loopback circuit 350 may be used to measure any phase shift, (p, based on the polar signal resulting from the digital power amplifier 440. If there is a phase shift, the delay unit 390A and / or delay unit 390B may adjust one or both of the first input signal and / or second input signal (e.g., based on commands by a controller 370) to offset a time delay associated with the phase shift. As previously discussed, phase shifts may be mapped to time delays based on a lookup table 362 stored in the memory 360.

[0083] FIG. 5 is a schematic diagram illustrating a phase shift in a polar transmission based on polar vectors according to one or more aspects of the disclosure. Specifically FIG. 5 shows graphs 500A and 500B that illustrate the absence or presence of phase shifts based on time delays of input signals. As previously discussed, such time delays may result from fluctuations in processes, voltages, and temperatures in devices for polar transmission. For each graph, the x-axis represents time while the y-axis represents phase, and phases 410 and 420 may correspond to those discussed in relation to the first input signal and the second input signal in FIG. 4. As the polar vector corresponding to the second input signal is coaxially contra-rotated relative to the polar vector corresponding to the first input signal, phase 420 is similarly shown in both graphs 500A and 500B as having an inverse (e.g., downward facing) slope to that of phase 410.

[0084] In particular, graph 500A shows a scenario where there is no time misalignment between the first input signal representing the AM component of the RF signal and the second input signal representing the PM component of the RF signal. For example, phase 410 associated with the first input signal begins at the same time as phase 420 associated with the second input signal that is outputted from the phase modulator 330. The digital power amplifier 320 may determine a difference between phases 410 and 420 when the respective signals are received (e.g., based on a product of the corresponding polar vectors). Due to the input signals aligning in time, the respective phases 410 and 420NRF Ref No. QLXX.P2142WO2496419W0 29 / 50subtract each other out. Although there is shown a phase offset in graph 500A, such phase offset may be treated as a background phase shift occurring due to measurement of phase data via the loopback circuit 350.

[0085] In contrast, graph 500B shows a scenario where there is time misalignment between the first input signal and the second input signal, as phase 420 associated with the second input signal begins at a later time point than phase 410. The difference thus results in an additional phase offset due to the time misalignment. After filtering background phase shift, the additional phase offset may be used to determine a time delay to adjust the phases of the input signals and therefore improve time alignment of the polar transmitter.

[0086] Figure 6 is a flow diagram of an example process 600 for improving time alignment in polar transmission according to one or more aspects of the disclosure. Operations of process 600 may be performed by a device used for polar transmission of RF signals, such as devices 300 or 400 as described above with reference to FIGs. 3 or 4, respectively. In some embodiments, various blocks may be performed by a processor or controller of the device (e.g., controller 370) based on computer-readable or processor readable instructions stored in a memory (e.g., memory 360) of the device. The example operations of process 600 may enable the device to improve time alignment in polar transmission.

[0087] At block 602, the device (e.g., via controller 370 of the device 300) may receive or determine based on a first input signal representing an AM component of an RF signal (e.g., on which a digital IQ signal may be based), a first polar vector. At block 604, the device (e.g., processor or controller of the device) may receive or determine, based on a second input signal representing a PM component of the RF signal (e.g., on which a digital IQ signal may be based), a second polar vector. The second polar vector may be coaxially contra-rotated relative to the first polar vector. As previously, discussed, the polar vector includes a magnitude component (r) and an angle component (9). The first and second polar vectors may be determined by using the magnitude component (r) to indicate the amplitude information represented by the first and second input signals, and using the angle component (9) to indicate the phase information represented by the first and second input signals, respectively. However, by coaxially contrarotating the second polar vector, the angle may be in an opposite direction from that of the first polar vector, but may be rotated to a degree or radian that is still commensurate and / or proportionate to the phase of the second input signal. Although polar vectors with magnitude and angle components are described through this application, it should be understood that the polar vector mayNRF Ref No. QLXX.P2142WO2406419W0 30 / 50take other formats and representations, including as cartesian or other representations. That is, the application of rotating vectors for adjusting time alignments may be accomplished using polar vectors in non-polar representations.

[0088] In some embodiments, the first input signal is a digital input in-phase / quadrature (IQ) signal representing the AM component of an RF signal, and the second input signal is a digital IQ signal representing the PM component of the RF signal. The first input signal and the second input signals may be received by a digital power amplifier (e.g., digital power amplifier 440, digital power amplifier 320, etc.). In some embodiments, circuitry and / or components within the digital power amplifier 320 (e.g., SCPAs 450A-450B, logic gate 430, etc.) may generate, or assist the processor to determining, the polar vectors.

[0089] At block 606, the device (e.g., via controller 370 of the device 300) may determine, based on the first polar vector and the second polar vector representing the IQ signals of the first and second input signals, a phase shift in the RF signal. For example, the device may include a loopback circuit (e.g., loopback circuit 350) configured to determine or measure the phase shift from a signal generated by a digital power amplifier (e.g., digital power amplifier 440, digital power amplifier 320, etc.). The signal generated by the digital power amplifier may be a polar signal based on the product of the first and second polar vector.

[0090] In some embodiments, blocks 602 through 606 may be performed as a single step by the device. For example, the device may receive the first polar vector and the second polar vector to determine the phase shift in the RF signal as a single step. Alternatively, blocks 602 through 606 may be performed as separate steps and / or as not a single step.

[0091] In some embodiments, the phase shift may be mapped to a time delay. For example, the phase shift may correspond to a time delay between the first input signal and the second input signal. Also or alternatively, the phase shift may correspond to a time delay between a baseband signal (e.g., generated via the oscillator 340) and the RF signal represented by the IQ signal. The mapping between the phase shift and the time delay may be determined via a lookup table stored in a memory of the device (e.g., lookup table 362 stored in memory 360).

[0092] At block 608, the device (e.g., via controller 370 of the device 300) may adjust, based on the phase shift, the RF signal (e.g., to be upconverted by the digital power amplifier 440 / 320). For example, the device may further include one or more delay units (e.g., delay units 390A-390B). The device (e.g., the via controller 370 of the device 300) can thus adjust the RF signal by causing the one or more delay units (e.g., delay units 390A-NRF Ref No. QLXX.P2142WO2406419W0 31 / 50390B) to adjust one or both of the first input signal or the second input signal to be delayed in time that is commensurate with, proportionate to, or otherwise corresponding to the phase shift. In some embodiments, the digital power amplifier 440 / 320 may be configured to adjust, based on the phase shift, the RF signal. The adjustment may reduce a time delay of the RF signal. Furthermore, in some embodiments, the digital power amplifier may be configured to determine the time delay using the one or more delay units.

[0093] For example, the device can offset the phase shift by determining, using the phase shift, the time delay, and may then offset, using the one or more delay units, the time delay between the baseband signal and the RF signal and / or between the first input signal and the second input signal.

[0094] In some embodiments, the device may further include a baseband mixer (e.g., baseband mixer 334). The device may adjust the RF signal by offsetting, via the baseband mixer, the phase shift from a baseband signal associated with the RF signal.

[0095] Figure 7 is a flow diagram of another example process 700 for improving time alignment in polar transmission according to one or more aspects of the disclosure. Operations of process 700 may be performed by a device used for polar transmission of RF signals, such as devices 300 or 400 as described above with reference to FIGs. 3 or 4, respectively. In some embodiments, various blocks may be performed by a processor or controller of the device (e.g., controller 370) based on computer-readable or processor readable instructions stored in a memory (e.g., memory 360) of the device. The example operations of process 700 may enable the device to improve time alignment in polar transmission. In some embodiments, various blocks or aspects of blocks of process 700 may be combined with, interchanged with, replaced with, and / or added to various blocks or aspects of blocks of process 600 for additional examples of improving time alignment in polar transmission according to one or more aspects of the disclosure.

[0096] At block 702, the device (e.g., via controller 370 of the device 300) may determine, based on a first polar vector and a second polar vector, a phase shift in an IQ signal. Also or alternatively, the phase shift may be determined for an RF signal on which the IQ signal may be based on. The first polar vector may represent an amplitude modulation (AM) component of the IQ signal and the second polar vector may represent a phase modulation (PM) component of the IQ signal. Moreover, the second polar vector may be coaxially contra-rotated relative to the first polar vector (e.g., the angle of rotation of the second polar vector may be in an opposite direction from that of the first polar vector, but mayNRF Ref No. QLXX.P2142WO2406419W0 32 / 50be rotated to a degree or radian that is still commensurate and / or proportionate to the phase of the second PM component of the IQ signal).

[0097] For example, input signals received by the digital power amplifier may include an AM component (e.g., the input signal received by the digital power amplifier directly from the hybrid phase module 310 (e.g., via an AM path)) and a PM component (e.g., received from the phase modulator 330 (e.g., via a PM path)). The input signal that is the AM component may be an IQ signal. In some embodiments, the IQ signal may be a baseband continuous wave (BB CW) having a frequency. When received by the digital power amplifier, the AM component may be characterized as, represented as, or transformed into a first polar vector having a rotation in a first direction (e.g., a counterclockwise direction). The value of the rotation (e.g., radians, degrees, etc.) may be based on the phase of the AM component of the IQ signal.

[0098] As previously discussed, the PM component may be an input signal received by the digital power amplifier 320 from the phase modulator 330. In some embodiments, the input signal corresponding to the PM component may be an IQ signal that is a conjugate of the IQ signal corresponding to the AM component transmitted by the hybrid phase module 310 to the digital power amplifier 320 (e.g., directly). Thus, the IQ signal corresponding to the PM component may be a BB CW that may have the same (or similar) frequency. For example, the phase modulator 330 may receive the same IQ signal from the hybrid phase module 310 but may output a phase modulated signal to the digital power amplifier 320. The phase modulated signal may be, comprise, or otherwise serve the basis for the PM component of the IQ signal received by the digital power amplifier 320. When received by the digital power amplifier 320, the PM component may be characterized as, represented as, or transformed to a second polar vector having a rotation in a second direction (e.g., clockwise). The value of the rotation (e.g., radians, degrees, etc.) may be based on the phase of the PM component of the IQ signal, but may be rotated in a direction opposite that of the AM component.

[0099] In some embodiments, the direction of the rotation or the value of the rotation of the first polar vector or the second polar vector may be relative to a polar vector representing or characterizing a signal generated by a low oscillator (e.g., an unmodulated or minimally modulated oscillator, such as but not limited to oscillator 340)).

[0100] In some embodiments, the output of the digital power amplifier 320 based on the AM and PM components of the IQ signal may be radio frequency continuous wave (RF CW). InNRF Ref No. QLXX.P2142WO2406419W0 33 / 50some embodiments, determining the phase shift in the IQ signal (e.g., the IQ signal serving as the basis for the AM and PM components and the first and second polar vectors, respectively) may be based on the product of the first polar vector and the second polar vector. If there are no delays occurring as a result of the phase modulation (or other paths in the device 300), it is expected that the coaxially contra-rotated first and second polar vectors may cancel out their phase differences, resulting in a net zero phase shift relative to the phase of the signal generated by the low oscillator 340. For example, the outputted RF CW from the digital power amplifier 320 may not have any rotation relative to the rotation of the phase exhibited by the low oscillator signal, in such ideal conditions. However, a delay in the PM component or any paths in the device (e.g., AM path, PM path, etc.) may result in a phase shift, therefore resulting in a rotation in the outputted RF CW, relative to the rotation exhibited by the low oscillator signal.

[0101] In some embodiments, the phase shift may be determined by applying the outputted RF CW of the digital power amplifier 320 to the loopback circuit 350. The loopback circuit 350 may downconvert the RF CW and determine a phase shift using one or more techniques described herein.

[0102] At block 710, the device may (e.g., via controller 370 of the device 300) adjust, based on the phase shift, an RF signal (e.g., the RF CW outputted by the digital power amplifier). For example, as previously discussed, the digital power amplifier 320 may apply the AM and PM components of the IQ signal to output a RF CW. Any phase shift may be exhibited by a rotation in a corresponding polar vector representing the RF CW, relative to the rotation in a low oscillator signal. The phase shift may correspond to a time delay between the first input signal and the second input signal. Also or alternatively, the phase shift may correspond to a time delay between a baseband signal (e.g., generated via the oscillator 340) and the RF signal represented by the IQ signal. The mapping between the phase shift and the time delay may be determined via a lookup table stored in a memory of the device (e.g., lookup table 362 stored in memory 360) and / or via other techniques described herein (e.g., by comparison to a subsequently determined phase shift using a subsequent (e.g., second set of first and second polar vectors based on an IQ signal with a second frequency).

[0103] For example, the aforementioned process (e.g., of determining the phase shift based on a set of first and second polar vectors representing the AM and PM components of an IQ signal) may be repeated again based on a subsequent IQ signal of the digital powerNRF Ref No. QLXX.P2142WO2406419W0 34 / 50amplifier 320 having a second frequency. The subsequent IQ signal having the second frequency may be represented via a second set of first and polar vectors representing the AM and PM components of the subsequent IQ signal. For example, the second set may be based on another first input signal being applied to the AM path of an IQ signal of the digital power amplifier 320 having the second frequency, and another second input signal being applied to the PM path of the IQ signal having the second frequency. As before, each of the first and second input signals may (e.g., in the absence of the other input signals) be coaxially contra-rotated (e.g., relative to a unmodulated or minimally modulated phase of a low oscillator), such that the phases are in opposite directions when represented as polar vectors. The subsequently outputted RF CW signal of the digital power amplifier in the second set may be downconverted by the loopback circuit 350 to determine a second phase shift.

[0104] The device (e.g., via controller 370) may use the first and second phase shifts (Phasei and Phase?, respectively) and the first and second frequencies (Freqi and Freq2, respectively) to determine a group delay (GD), for example, via the expression: GD = §rouP delay (GD) value may be used to compensate and / orotherwise adjust a delay in the PM path of the device 300 and / or otherwise align the PM and AM paths of the device 300. In some embodiments, the device (e.g., via controller 370 of the device 300) may adjust, based on the phase shift, the RF signal via one or more delay units (e.g., delay units 390A-390B). For example, the device may cause the one or more delay units to adjust input signals for the AM component and / or the PM component to be delayed in time that is commensurate with, proportionate to, or otherwise corresponding to the phase shift. The adjustment may cause the adjustment of the RF signal outputted by the digital power amplifier 320.

[0105] In one or more aspects, techniques for supporting wireless communications may include additional aspects, such as any single aspect or any combination of aspects described below or in connection with one or more other processes or devices described elsewhere herein.

[0106] In a first aspect, supporting wireless communication may include an apparatus configured for polar transmission with improved time alignment. The apparatus includes: a memory storing processor-readable code; and at least one processor coupled to the memory. The at least one processor configured to execute the processor-readable code to cause the at least one processor to perform operations including: determining or receiving, based on aNRF Ref No. QLXX.P2142WO2406419W0 35 / 50first input signal representing an amplitude modulation (AM) component of a radiofrequency (RF) signal, a first polar vector; determining or receiving, based on a second input signal representing a phase modulation (PM) component of the RF signal, a second polar vector, wherein the second polar vector is coaxially contra-rotated relative to the first polar vector; determining, based on the first polar vector and the second polar vector, a phase shift in the RF signal; and adjusting, based on the phase shift, the RF signal.

[0107] In a second aspect, in combination with the first aspect, the apparatus further includes a baseband mixer. The at least one processor is configured to adjust the RF signal by: offsetting, via the baseband mixer, the phase shift from a baseband signal associated with the RF signal.

[0108] In a third aspect, in combination with one or more of the first aspect or the second aspect, the apparatus further includes a loopback circuit configured to measure the phase shift. The at least one processor is configured to determine the phase shift using the loopback circuit to monitor correction of a time misalignment.

[0109] In a fourth aspect, in combination with one or more of the first aspect through the third aspect, the apparatus further includes a delay unit. Prior to the adjusting, the phase shift corresponds to a time delay between the baseband signal and the RF signal. The at least one processor is configured to offset the phase shift by: determining, using the phase shift, the time delay; and offsetting, using the delay unit, the time delay between the baseband signal and the RF signal.

[0110] In a fifth aspect, in combination with one or more of the first aspect through the fourth aspect, the at least one processor is configured to: determine the first polar vector, determine the second polar vector, adjust the RF signal, and measure the phase shift iteratively until the phase shift satisfies a predetermined threshold.[OHl] In a sixth aspect, in combination with one or more of the first aspect through the fifth aspect, the apparatus further includes a digital power amplifier. The digital power amplifier is configured to receive the first input signal and the second input signal.

[0112] In a seventh aspect, in combination with one or more of the first aspect through the sixth aspect, the first input signal is an in-phase / quadrature (IQ) input signal representing the AM component of the RF signal. The second input signal is an IQ input representing the PM component of the RF signal.NRF Ref No. QLXX.P2142WO2406419W0 36 / 50

[0113] In an eighth aspect, in combination with one or more of the first aspect through the seventh aspect, the at least one processor is further configured to, prior to the adjusting: apply, to the first polar vector and the second polar vector, a frequency modulation (FM) dithering to offset an interference.

[0114] In a ninth aspect, a method is disclosed for polar transmission with improved time alignment. The method includes: determining or receiving, by a processor, based on a first input signal representing an amplitude modulation (AM) component of a radiofrequency (RF) signal, a first polar vector; determining or receiving, by the processor, based on a second input signal representing a phase modulation (PM) component of the RF signal, a second polar vector, wherein the second polar vector is coaxially contra-rotated relative to the first polar vector; determining, by the processor, based on the first polar vector and the second polar vector, a phase shift in the RF signal; and adjusting, by the processor, based on the phase shift, the RF signal.

[0115] In a tenth aspect, in combination with the ninth aspect, adjusting the phase shift includes:offsetting, by the processor, and via a baseband mixer, the phase shift from a baseband signal associated with the RF signal.

[0116] In an eleventh aspect, in combination with one or more of the ninth aspect through the tenth aspect, prior to the adjusting, the phase shift corresponds to a time delay between the baseband signal and the RF signal.

[0117] In a twelfth aspect, in combination with one or more of the ninth aspect through the eleventh aspect, offsetting the phase shift includes: offsetting, using a delay unit, the time delay between the baseband signal and the RF signal.

[0118] In a thirteenth aspect, in combination with one or more of the ninth aspect through the twelfth aspect, determining the first polar vector, the determining the second polar vector, the determining the phase shift, and the adjusting the RF signal, are performed iteratively until the phase shift satisfies a predetermined threshold.

[0119] In a fourteenth aspect, in combination with one or more of the ninth aspect through the thirteenth aspect, the method further includes: receiving the first input signal prior to determining the first polar vector, wherein the first input signal comprises an in- phase / quadrature (IQ) input signal representing the AM component of the RF signal; and receiving the second input signal prior to determining the second polar vector, wherein the second input signal comprises an IQ input signal representing the PM component of the RF signal.NRF Ref No. QLXX.P2142WO2406419W0 37 / 50

[0120] In a fifteenth aspect, in combination with one or more of the ninth aspect through the fourteenth aspect, the method further includes: prior to the adjusting: applying, by the processor, to the first polar vector and the second polar vector, a frequency modulation (FM) dithering to offset an interference.

[0121] In a sixteenth aspect, in combination with one or more of the first aspect through the fifteenth aspect, a transmitter device is disclosed that includes: a digital power amplifier configured to receive a first input signal representing an amplitude modulation (AM) component of a radiofrequency (RF) signal and a second input signal representing a phase modulation (PM) component of the RF signal; a memory storing processor-readable code; and at least one processor coupled to the memory. The at least one processor is configured to execute the processor-readable code to cause the at least one processor to: determine, based on the first input signal, a first polar vector; determine, based on the second input signal, a second polar vector, wherein the second polar vector is coaxially contra-rotated relative to the first polar vector; determine, based on the first polar vector and the second polar vector, a phase shift in the RF signal; and adjust, based on the phase shift, the RF signal, wherein the adjustment reduces a time delay between the RF signal and a baseband signal associated with the RF signal.

[0122] In a seventeenth aspect, in combination with the sixteenth aspect, the transmitter device further includes one or more delay units. The phase shift corresponds to the time delay between the baseband signal and the RF signal. The at least one processor is configured to determine the time delay using the one or more delay units.

[0123] In an eighteenth aspect, in combination with one or more of the sixteenth aspect through the seventeenth aspect, the at least one processor is configured to: determine the first polar vector, determine the second polar vector, and adjust the phase shift, until the phase shift satisfies a predetermined threshold.

[0124] In a nineteenth aspect, in combination with one or more of the sixteenth aspect through the eighteenth aspect, the digital power amplifier is a switched capacitor power amplifier.

[0125] In a twentieth aspect, in combination with one or more of the sixteenth aspect through the nineteenth aspect, the transmitter device further includes the transmitter device further includes a baseband mixer configured to offset the phase shift from the baseband signal.

[0126] In a twenty first aspect, a transmitter device is disclosed. The transmitter device may include: a digital power amplifier configured to receive a first input signal corresponding to a first polar vector rotated in a first direction and a second input signal correspondingNRF Ref No. QLXX.P2142WO2406419W0 38 / 50to a second polar vector rotated in a second direction; a phase modulator circuit coupled to the digital power amplifier and configured to: output a phase modulated signal to the digital power amplifier, wherein the second input signal is based on the phase modulated signal; and a loopback circuit configured to determine a phase shift at an output of the digital power amplifier.

[0127] In a twenty second aspect, in combination with the twenty first aspect, the phase shift is determined based on the first polar vector and the second polar vector. The digital power amplifier is further configured to: adjust, based on the phase shift, an RF signal. The adjustment reduces a time delay of the RF signal.

[0128] In a twenty third aspect, in combination with one or more of the twenty first aspect or the twenty second aspect, the transmitter device further includes one or more delay units. The digital power amplifier is further configured to determine the time delay using the one or more delay units.

[0129] In a twenty fourth aspect, in combination with one or more of the twenty first aspect through the twenty third aspect, the digital power amplifier is configured to: adjust the phase shift until the phase shift satisfies a predetermined threshold.

[0130] In a twenty fifth aspect, in combination with one or more of the twenty first aspect through the twenty fourth aspect, the digital power amplifier is a switched capacitor power amplifier.

[0131] In a twenty sixth aspect, an apparatus is disclosed for improving time alignment in transmission devices. The apparatus includes a memory storing processor-readable code; and at least one processor coupled to the memory. The at least one processor is configured to execute the processor-readable code to cause the at least one processor to perform operations including: determining, based on a first polar vector representing an amplitude modulation (AM) component of an in-phase quadrature (IQ) signal and a second polar vector representing a phase modulation (PM) component of the IQ signal, a phase shift in the IQ signal. The second polar vector is coaxially contra-rotated relative to the first polar vector. The operations further include adjusting, based on the phase shift, a radio frequency (RF) signal.

[0132] In a twenty seventh aspect, in combination with the twenty sixth aspect, the apparatus further includes a loopback circuit configured to measure the phase shift. The at least one processor is configured to determine the phase shift using the loopback circuit to monitor correction of a time misalignment.NRF Ref No. QLXX.P2142WO2406419W0 39 / 50

[0133] In a twenty eighth aspect, in combination with the twenty sixth aspect or the twenty seventh aspect, the apparatus further includes a baseband mixer. The at least one processor is configured to adjust the RF signal by: offsetting, via the baseband mixer, the phase shift from a baseband signal associated with the RF signal.

[0134] In a twenty ninth aspect, in combination with one or more of the twenty sixth aspect through the twenty eighth aspect, the apparatus further includes a delay unit. Prior to the adjusting, the phase shift corresponds to a time delay between the baseband signal and the RF signal. The at least one processor is configured to offset the phase shift by: determining, using the phase shift, the time delay; and offsetting, using the delay unit, the time delay between the baseband signal and the RF signal.

[0135] In a thirtieth aspect, in combination with one or more of the twenty sixth aspect through the twenty ninth aspect, the at least one processor is configured to: adjust the RF signal and measure the phase shift iteratively until the phase shift satisfies a predetermined threshold.

[0136] In a thirty first aspect, in combination with one or more of the twenty sixth aspect through the thirtieth aspect, the apparatus further includes a digital power amplifier. The digital power amplifier is configured to receive the AM component of the IQ signal and the PM component of the IQ signal; and output the RF signal based on the IQ signal.

[0137] In a thirty second aspect, in combination with one or more of the twenty sixth aspect through the thirty first aspect, the apparatus further includes a phase modulator coupled to the digital power amplifier and configured to output a phase modulated IQ signal to the digital power amplifier. The PM component of the IQ signal may be based on the phase modulated IQ signal.

[0138] In a thirty third aspect, in combination with one or more of the twenty sixth aspect through the thirty second aspect, the at least one processor is further configured to, prior to the adjusting: apply, to the first polar vector and the second polar vector, a frequency modulation (FM) dithering to offset an interference.

[0139] In a thirty fourth aspect, a method is disclosed for improving time alignment in a transmission device. The method includes: determining, by a processor, based on a first polar vector representing an amplitude modulation (AM) component of an in-phase quadrature IQ signal and a second polar vector representing a phase modulation (PM) component of the IQ signal, a phase shift in the IQ signal, wherein the second polar vectorNRF Ref No. QLXX.P2142WO2406419W0 40 / 50is coaxially contra-rotated relative to the first polar vector; and adjusting, by the processor, based on the phase shift, a radio frequency (RF) signal.

[0140] In a thirty fifth aspect, in combination with the thirty fourth aspect, adjusting the phase shift includes: offsetting, by the processor, and via a baseband mixer, the phase shift from a baseband signal associated with the RF signal.

[0141] In a thirty sixth aspect, in combination with the thirty fourth aspect or the thirty fifth aspect, prior to the adjusting, the phase shift corresponds to a time delay between the baseband signal and the RF signal.

[0142] In a thirty seventh aspect, in combination with one or more of the thirty fourth aspect through the thirty sixth aspect, offsetting the phase shift includes: offsetting, using a delay unit, the time delay between the baseband signal and the RF signal.

[0143] In a thirty eighth aspect, in combination with one or more of the thirty fourth aspect through the thirty seventh aspect, determining the phase shift and adjusting the RF signal are performed iteratively until the phase shift satisfies a predetermined threshold.

[0144] In a thirty ninth aspect, in combination with one or more of the thirty fourth aspect through the thirty eighth aspect, the method further includes: determining, based on the AM component of the IQ signal and the PM component of the IQ signal, the RF signal.

[0145] In a fortieth aspect, in combination with one or more of the thirty fourth aspect through the thirty ninth aspect, the method further includes, prior to the adjusting: applying, by the processor, to the first polar vector and the second polar vector, a frequency modulation (FM) dithering to offset an interference.

[0146] Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0147] Components, the functional blocks, and the modules described herein with respect to FIGs. 1-4 include processors, electronics devices, hardware devices, electronics components, logical circuits, memories, software codes, firmware codes, among other examples, or any combination thereof. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, application, software applications, software packages,NRF Ref No. QLXX.P2142WO2406419W0 41 / 50routines, subroutines, objects, executables, threads of execution, procedures, and / or functions, among other examples, whether referred to as software, firmware, middleware, microcode, hardware description language or otherwise. In addition, features discussed herein may be implemented via specialized processor circuitry, via executable instructions, or combinations thereof.

[0148] Those of skill in the art that one or more blocks (or operations) described with reference to FIGs. 3 and 4 may be combined with one or more blocks (or operations) described with reference to another of the figures. For example, one or more blocks (or operations) of FIG. 3 may be combined with one or more blocks (or operations) of FIG. 1. As another example, one or more blocks associated with FIG. 4 may be combined with one or more blocks (or operations) associated with FIGs. 1. Additionally, or alternatively, one or more operations described above with reference to FIGs. 1-4 may be combined with one or more operations described with reference to FIGs. 5-6.

[0149] Those of skill in the art would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure. Skilled artisans will also readily recognize that the order or combination of components, methods, or interactions that are described herein are merely examples and that the components, methods, or interactions of the various aspects of the present disclosure may be combined or performed in ways other than those illustrated and described herein.

[0150] The various illustrative logics, logical blocks, modules, circuits and algorithm processes described in connection with the implementations disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. The interchangeability of hardware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules,NRF Ref No. QLXX.P2142WO2406419W0 42 / 50circuits and processes described above. Whether such functionality is implemented in hardware or software depends upon the particular application and design constraints imposed on the overall system.

[0151] The hardware and data processing apparatus used to implement the various illustrative logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general- purpose processor may be a microprocessor, or, any conventional processor, controller, microcontroller, or state machine. In some implementations, a processor may be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, particular processes and methods may be performed by circuitry that is specific to a given function.

[0152] In one or more aspects, the functions described may be implemented in hardware, digital electronic circuitry, computer software, firmware, including the structures disclosed in this specification and their structural equivalents thereof, or in any combination thereof. Implementations of the subject matter described in this specification also may be implemented as one or more computer programs, which is one or more modules of computer program instructions, encoded on a computer storage media for execution by, or to control the operation of, data processing apparatus.

[0153] If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. The processes of a method or algorithm disclosed herein may be implemented in a processor-executable software module which may reside on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that may be enabled to transfer a computer program from one place to another. A storage media may be any available media that may be accessed by a computer. By way of example, and not limitation, such computer-readable media may include random-access memory (RAM), read-only memory (ROM), electrically erasable programmable read-NRF Ref No. QLXX.P2142WO2406419W0 43 / 50only memory (EEPROM), CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store desired program code in the form of instructions or data structures and that may be accessed by a computer. Also, any connection may be properly termed a computer-readable medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. Additionally, the operations of a method or algorithm may reside as one or any combination or set of codes and instructions on a machine readable medium and computer-readable medium, which may be incorporated into a computer program product.

[0154] Various modifications to the implementations described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to some other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

[0155] Additionally, a person having ordinary skill in the art will readily appreciate, opposing terms such as “upper” and “lower” or “front” and back” or “top” and “bottom” or “forward” and “backward” are sometimes used for ease of describing the figures, and indicate relative positions corresponding to the orientation of the figure on a properly oriented page, and may not reflect the proper orientation of any device as implemented.

[0156] Certain features that are described in this specification in the context of separate implementations also may be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also may be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination may in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

[0157] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieveNRF Ref No. QLXX.P2142WO2406419W0 44 / 50desirable results. Further, the drawings may schematically depict one or more example processes in the form of a flow diagram. However, other operations that are not depicted may be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations may be performed before, after, simultaneously, or between any of the illustrated operations. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems may generally be integrated together in a single software product or packaged into multiple software products. Additionally, some other implementations are within the scope of the following claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve desirable results.

[0158] As used herein, including in the claims, the term “or,” when used in a list of two or more items, means that any one of the listed items may be employed by itself, or any combination of two or more of the listed items may be employed. For example, if a composition is described as containing components A, B, or C, the composition may contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of’ indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (that is A and B and C) or any of these in any combination thereof. The term “substantially” is defined as largely but not necessarily wholly what is specified (and includes what is specified; for example, substantially 90 degrees includes 90 degrees and substantially parallel includes parallel), as understood by a person of ordinary skill in the art. In any disclosed implementations, the term “substantially” may be substituted with “within [a percentage] of’ what is specified, where the percentage includes .1, 1, 5, or 10 percent.

[0159] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs describedNRF Ref No. QLXX.P2142WO2406419W0 45 / 50herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.NRF Ref No. QLXX.P2142WO

Claims

1. 2406419W0 46 / 50CLAIMS WHAT IS CLAIMED IS:

1. An apparatus, comprising:a memory storing processor-readable code; andat least one processor coupled to the memory, the at least one processor configured to execute the processor-readable code to cause the at least one processor to perform operations including:determining, based on a first polar vector representing an amplitude modulation (AM) component of an in-phase quadrature (IQ) signal and a second polar vector representing a phase modulation (PM) component of the IQ signal, a phase shift in the IQ signal, wherein the second polar vector is coaxially contra-rotated relative to the first polar vector; andadjusting, based on the phase shift, a radio frequency (RF) signal.

2. The apparatus of claim 1, further comprising a loopback circuit configured to measure the phase shift, wherein the at least one processor is configured to determine the phase shift using the loopback circuit to monitor correction of a time misalignment.

3. The apparatus of claim 1, further comprising a baseband mixer, wherein the at least one processor is configured to adjust the RF signal by:offsetting, via the baseband mixer, the phase shift from a baseband signal associated with the RF signal.

4. The apparatus of claim 3, further comprising a delay unit,wherein, prior to the adjusting, the phase shift corresponds to a time delay between the baseband signal and the RF signal,wherein the at least one processor is configured to offset the phase shift by:NRF Ref No. QLXX.P2142WO2406419W0 47 / 50determining, using the phase shift, the time delay; andoffsetting, using the delay unit, the time delay between the baseband signal and the RF signal.

5. The apparatus of claim 3, wherein the at least one processor is configured to:adjust the RF signal and measure the phase shift iteratively until the phase shift satisfies a predetermined threshold.

6. The apparatus of claim 1, further comprising a digital power amplifier, wherein the digital power amplifier is configured to receive the AM component of the IQ signal and the PM component of the IQ signal; and output the RF signal based on the IQ signal.

7. The apparatus of claim 6, further comprising a phase modulator coupled to the digital power amplifier and configured to output a phase modulated IQ signal to the digital power amplifier, wherein the PM component of the IQ signal is based on the phase modulated IQ signal.

8. The apparatus of claim 1, wherein the at least one processor is further configured to, prior to the adjusting:apply, to the first polar vector and the second polar vector, a frequency modulation (FM) dithering to offset an interference.

9. A method, comprising:determining, by a processor, based on a first polar vector representing an amplitude modulation (AM) component of an in-phase quadrature IQ signal and a second polar vector representing a phase modulation (PM) component of the IQ signal, a phase shift in the IQ signal, wherein the second polar vector is coaxially contra-rotated relative to the first polar vector; andadjusting, by the processor, based on the phase shift, a radio frequency (RF) signal.

10. The method of claim 9, wherein adjusting the phase shift comprises:NRF Ref No. QLXX.P2142WO2406419W0 48 / 50offsetting, by the processor, and via a baseband mixer, the phase shift from a baseband signal associated with the RF signal.

11. The method of claim 10, wherein, prior to the adjusting, the phase shift corresponds to a time delay between the baseband signal and the RF signal.

12. The method of claim 11, wherein offsetting the phase shift comprises:offsetting, using a delay unit, the time delay between the baseband signal and the RF signal.

13. The method of claim 9, wherein determining the phase shift and adjusting the RF signal are performed iteratively until the phase shift satisfies a predetermined threshold.

14. The method of claim 9, further comprising:determining, based on the AM component of the IQ signal and the PM component of the IQ signal, the RF signal .

15. The method of claim 9, further comprising, prior to the adjusting:applying, by the processor, to the first polar vector and the second polar vector, a frequency modulation (FM) dithering to offset an interference.

16. A transmitter device, comprising:a digital power amplifier configured to receive a first input signal corresponding to a first polar vector rotated in a first direction and a second input signal corresponding to a second polar vector rotated in a second direction;a phase modulator circuit coupled to the digital power amplifier and configured to:output a phase modulated signal to the digital power amplifier, wherein the second input signal is based on the phase modulated signal; anda loopback circuit configured to determine a phase shift at an output of the digital power amplifier.NRF Ref No. QLXX.P2142WO2406419W0 49 / 5017. The transmitter device of claim 16, wherein the phase shift is determined based on the first polar vector and the second polar vector, wherein the digital power amplifier is further configured to:adjust, based on the phase shift, an RF signal, wherein the adjustment reduces a time delay of the RF signal.

18. The transmitter device of claim 17, further comprising one or more delay units, wherein the digital power amplifier is further configured to determine the time delay using the one or more delay units.

19. The transmitter device of claim 17, wherein the digital power amplifier is configured to:adjust the phase shift until the phase shift satisfies a predetermined threshold.

20. The transmitter device of claim 16, wherein the digital power amplifier is configured to output the RF signal based on the first input signal and the second input signal.NRF Ref No. QLXX.P2142WO

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