WO2022217536A1 - Air to ground signaling enhancement for multiple waveform use - Google Patents
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- WO2022217536A1 WO2022217536A1 PCT/CN2021/087474 CN2021087474W WO2022217536A1 WO 2022217536 A1 WO2022217536 A1 WO 2022217536A1 CN 2021087474 W CN2021087474 W CN 2021087474W WO 2022217536 A1 WO2022217536 A1 WO 2022217536A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
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- H04L5/0003—Two-dimensional division
- H04L5/0005—Time-frequency
- H04L5/0007—Time-frequency the frequencies being orthogonal, e.g. OFDM(A), DMT
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- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
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- H04L5/0091—Signaling for the administration of the divided path
- H04L5/0096—Indication of changes in allocation
Definitions
- This application relates to wireless communication systems, and more particularly to techniques to support multiple waveforms in user equipment (UE) .
- UE user equipment
- Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) .
- a wireless multiple-access communications system may include a number of base stations (BSs) , each simultaneously supporting communications for multiple communication devices, which may be otherwise known as user equipment (UE) .
- BSs base stations
- UE user equipment
- NR next generation new radio
- LTE long term evolution
- NR next generation new radio
- 5G 5 th Generation
- LTE long term evolution
- NR next generation new radio
- LTE long term evolution
- NR next generation new radio
- NR is designed to provide a lower latency, a higher bandwidth or a higher throughput, and a higher reliability than LTE.
- NR is designed to operate over a wide array of spectrum bands, for example, from low-frequency bands below about 1 gigahertz (GHz) and mid-frequency bands from about 1 GHz to about 6 GHz, to high-frequency bands such as mmWave bands.
- GHz gigahertz
- NR is also designed to operate across different spectrum types, from licensed spectrum to unlicensed and shared spectrum. Spectrum sharing enables operators to opportunistically aggregate spectrums to dynamically support high-bandwidth services. Spectrum sharing can extend the benefit of NR technologies to operating entities that may not have access to a licensed spectrum.
- NR technology may also make use of a variety of different base station and user equipment technologies to maintain communication at acceptable throughput rates.
- An example type of base station and user equipment technology includes air to ground (ATG) applications.
- An example of an ATG application includes a base station having antennas oriented generally upward communicating with an aircraft-based user equipment.
- ATG base stations may have large radio frequency (RF) footprints, e.g., a radius of hundreds of kilometers.
- RF radio frequency
- a typical terrestrial base station may have a footprint of only a few kilometers. Therefore, an ATG base station and an ATG UE may benefit from use of techniques to address issues such as increased time delay and Doppler effect, which may affect ATG applications more than terrestrial applications.
- a method performed by a user equipment includes processing configuration information specifying communication using a first waveform in a first bandwidth part (BWP) or a first component carrier (CC) and a second waveform in a second BWP or a second CC, wherein the first waveform and the second waveform are different; communicating with a base station using the first waveform according to the configuration information; and subsequent to using the first waveform, communicating with the base station using the second waveform according to the configuration information.
- BWP bandwidth part
- CC component carrier
- a UE in another aspect, includes: a transceiver; and a processor controlling the transceiver, the processor configured to: process configuration information specifying uplink communications using an orthogonal time frequency and space (OTFS) waveform or a single carrier waveform and specifying downlink communication using an orthogonal frequency division multiplexing (OFDM) waveform; communicate with a base station using the OTFS waveform or the single carrier waveform in uplink according to the configuration information; and communicate with the base station using the OFDM waveform in downlink according to the configuration information.
- OTFS orthogonal time frequency and space
- OFDM orthogonal frequency division multiplexing
- a UE in another aspect, includes: means for communicating with a base station using a first waveform; means for processing configuration information from the base station specifying a parameter for a second waveform; and means for rate matching with respect to the second waveform, wherein the first waveform and the second waveform are different.
- a non-transitory computer-readable medium having program code recorded thereon includes: code for processing configuration information specifying communication using a first waveform in a first bandwidth part (BWP) or a first component carrier (CC) and a second waveform in a second BWP or a second CC, wherein the first waveform and the second waveform are different; code for communicating with a base station using the first waveform according to the configuration information; and code for communicating with the base station using the second waveform according to the configuration information subsequent to using the first waveform.
- BWP bandwidth part
- CC component carrier
- FIG. 1 illustrates a wireless communication network according to some aspects of the present disclosure.
- FIG. 2 illustrates a radio frame structure according to some aspects of the present disclosure.
- FIG. 3 illustrates a block diagram of an example SSB, according to some aspects of the present disclosure.
- FIG. 4 is an illustration of example numerologies according to some aspects of the present disclosure.
- FIG. 5 is an illustration of an example relationship between an air to ground (ATG) cell and two different terrestrial cells, including illustrating interference among UEs, according to some aspects of the present disclosure.
- ATG air to ground
- FIG. 6 is an illustration of an example method according to some aspects of the present disclosure.
- FIG. 7 is an illustration of an example method according to some aspects of the present disclosure.
- FIG. 8 is an illustration of an example method according to some aspects of the present disclosure.
- FIG. 9 is a block diagram of a user equipment (UE) according to some aspects of the present disclosure.
- FIG. 10 is a block diagram of an exemplary base station (BS) according to some aspects of the present disclosure.
- various implementations include methods of wireless communication, apparatuses, and non-transitory computer-readable media that provide support for using multiple waveforms, which may be applied to both terrestrial user equipment (UE) and air to ground (ATG) UEs.
- UE terrestrial user equipment
- ATG air to ground
- a base station configures a UE to use different waveforms with different respective bandwidth parts or component carriers.
- the base station may configure the UE to use different waveforms for uplink and downlink communications, respectively.
- the base station may configure the UE to perform rate matching around different waveforms.
- wireless communications systems also referred to as wireless communications networks.
- 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, Global System for Mobile Communications (GSM) networks, 5 th Generation (5G) or new radio (NR) networks, as well as other communications networks.
- CDMA code division multiple access
- TDMA time division multiple access
- FDMA frequency division multiple access
- OFDMA orthogonal FDMA
- SC-FDMA single-carrier FDMA
- LTE Long Term Evolution
- GSM Global System for Mobile Communications
- 5G 5 th Generation
- NR new radio
- 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.
- E-UTRA evolved UTRA
- IEEE Institute of Electrical and Electronics Engineers
- GSM Global System for Mobile communications
- LTE long term evolution
- UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided from an organization named “3 rd Generation Partnership Project” (3GPP)
- cdma2000 is described in documents from an organization named “3 rd Generation Partnership Project 2” (3GPP2) .
- 3GPP 3rd Generation Partnership Project
- LTE long term evolution
- the 3GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices.
- the present disclosure is concerned with the evolution of wireless technologies from LTE, 4G, 5G, NR, and beyond with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces.
- 5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface.
- 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 (IoTs) with a ULtra-high density (e.g., ⁇ 1M nodes/km 2 ) , ultra-low complexity (e.g., ⁇ 10s 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 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 2 ) , extreme data rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates) , and deep awareness with advanced discovery and optimizations.
- IoTs Internet of things
- the 5G NR may be implemented to use optimized OFDM-based waveforms with scalable numerology and transmission time interval (TTI) ; having a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD) /frequency division duplex (FDD) design; and with advanced wireless technologies, such as massive multiple input, multiple output (MIMO) , robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility.
- TTI transmission time interval
- MIMO massive multiple input, multiple output
- mmWave millimeter wave
- Scalability of the numerology in 5G NR with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments.
- subcarrier spacing may occur with 15 kHz, for example over 5, 10, 20 MHz, and the like bandwidth (BW) .
- BW bandwidth
- subcarrier spacing may occur with 30 kHz over a 80/100 MHz BW.
- subcarrier spacing may occur with 60 kHz over a 160 MHz BW.
- subcarrier spacing may occur with 120 kHz over a 500 MHz BW.
- the scalable numerology of the 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.
- QoS quality of service
- the efficient multiplexing of long and short TTIs may allow transmissions to start on symbol boundaries.
- 5G NR also contemplates a self-contained integrated subframe design with uplink/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 /downlink that may be flexibly configured on a per-cell basis to dynamically switch between uplink (UL) and downlink (DL) to meet the current traffic needs.
- FIG. 1 illustrates a wireless communication network 100 according to some aspects of the present disclosure.
- the network 100 may be a 5G network.
- the network 100 includes a number of base stations (BSs) 105 (individually labeled as 105a, 105b, 105c, 105d, 105e, and 105f) and other network entities.
- a BS 105 may be a station that communicates with UEs 115 and may also be referred to as an evolved node B (eNB) , a next generation eNB (gNB) , an access point, and the like.
- eNB evolved node B
- gNB next generation eNB
- Each BS 105 may provide communication coverage for a particular geographic area.
- the term “cell” can refer to this particular geographic coverage area of a BS 105 and/or a BS subsystem serving the coverage area, depending on the context in which the term is used.
- the actions of FIG. 7 may be performed by any of BSs 105.
- a BS 105 may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and/or other types of cell.
- a macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted 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 BS for a macro cell may be referred to as a macro BS.
- a BS for a small cell may be referred to as a small cell BS, a pico BS, a femto BS or a home BS. In the example shown in FIG.
- the BSs 105b, 105d, and 105e may be regular macro BSs, while the BSs 105a and 105c may be macro BSs enabled with one of three dimension (3D) , full dimension (FD) , or massive MIMO.
- the BSs 105a and 105c may take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity.
- the BS 105f may be a small cell BS which may be a home node or portable access point.
- a BS 105 may support one or multiple (e.g., two, three, four, and the like) cells.
- the network 100 may support synchronous or asynchronous operation.
- the BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time.
- the BSs may have different frame timing, and transmissions from different BSs may not be aligned in time.
- the UEs 115 are dispersed throughout the wireless network 100, and each UE 115 may be stationary or mobile.
- a UE 115 may also be referred to as a terminal, a mobile station, a subscriber unit, a station, or the like.
- a UE 115 may be a cellular phone, a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, or the like.
- PDA personal digital assistant
- WLL wireless local loop
- a UE 115 may be a device that includes a Universal Integrated Circuit Card (UICC) .
- a UE may be a device that does not include a UICC.
- UICC Universal Integrated Circuit Card
- the UEs 115 that do not include UICCs may also be referred to as IoT devices or internet of everything (IoE) devices.
- the UEs 115a-115d are examples of mobile smart phone-type devices accessing network 100.
- a UE 115 may also be a machine specifically configured for connected communication, including machine type communication (MTC) , enhanced MTC (eMTC) , narrowband IoT (NB-IoT) and the like.
- MTC machine type communication
- eMTC enhanced MTC
- NB-IoT narrowband IoT
- the UEs 115e-115h are examples of various machines configured for communication that access the network 100.
- the UEs 115i-115k are examples of vehicles equipped with wireless communication devices configured for communication that access the network 100.
- a UE 115 may be able to communicate with any type of the BSs, whether macro BS, small cell, or the like.
- a lightning bolt e.g., communication links indicates wireless transmissions between a UE 115 and a serving BS 105, which is a BS designated to serve the UE 115 on the downlink (DL) and/or uplink (UL) , desired transmission between BSs 105, backhaul transmissions between BSs, or sidelink transmissions between UEs 115.
- Figure 5 provides other examples of BSs 105 and UEs 115, and it is understood that those BSs 105 and UEs 115 operate the same as or similarly to those described with respect to Figure 1. For instance, Figure 5 illustrates an ATG BS 105g and three ATG UEs 115l-n. These additional assets are described in more detail below.
- the BSs 105a and 105c may serve the UEs 115a and 115b using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity.
- the macro BS 105d may perform backhaul communications with the BSs 105a and 105c, as well as small cell, the BS 105f.
- the macro BS 105d may also transmit multicast services which are subscribed to and received by the 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.
- the BSs 105 may also communicate with a core network.
- the core network may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions.
- IP Internet Protocol
- At least some of the BSs 105 (e.g., which may be an example of a gNB or an access node controller (ANC) ) may interface with the core network through backhaul links (e.g., NG-C, NG-U, etc. ) and may perform radio configuration and scheduling for communication with the UEs 115.
- the BSs 105 may communicate, either directly or indirectly (e.g., through core network) , with each other over backhaul links (e.g., X1, X2, etc. ) , which may be wired or wireless communication links.
- the network 100 may also support mission critical communications with ultra-reliable and redundant links for mission critical devices, such as the UE 115e, which may be a drone. Redundant communication links with the UE 115e may include links from the macro BSs 105d and 105e, as well as links from the small cell BS 105f.
- UE 115f e.g., a thermometer
- UE 115g e.g., smart meter
- UE 115h e.g., wearable device
- the network 100 may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such as vehicle-to-vehicle (V2V) , vehicle-to-everything (V2X) , cellular-V2X (C-V2X) communications between a UE 115i, 115j, or 115k and other UEs 115, and/or vehicle-to-infrastructure (V2I) communications between a UE 115i, 115j, or 115k and a BS 105.
- BS 105b is shown as a non-terrestrial network (NTN) resource, such as a satellite that orbits the earth.
- NTN non-terrestrial network
- BS 105b may include multiple antenna arrays, each array forming a relatively fixed beam.
- BS 105b may be configured as a single cell with multiple beams and BWPs, as explained in more detail below.
- the network 100 utilizes OFDM-based waveforms for communications.
- An OFDM-based system may partition the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, bins, or the like. Each subcarrier may be modulated with data.
- the subcarrier spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system BW.
- the system BW may also be partitioned into subbands. In other instances, the subcarrier spacing and/or the duration of TTIs may be scalable.
- the BSs 105 can assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RB) ) for downlink (DL) and uplink (UL) transmissions in the network 100.
- DL refers to the transmission direction from a BS 105 to a UE 115
- UL refers to the transmission direction from a UE 115 to a BS 105.
- the communication can be in the form of radio frames.
- a radio frame may be divided into a plurality of subframes or slots, for example, about 10. Each slot may be further divided into mini-slots. In a FDD mode, simultaneous UL and DL transmissions may occur in different frequency bands.
- each subframe includes a UL subframe in a UL frequency band and a DL subframe in a DL frequency band.
- UL and DL transmissions occur at different time periods using the same frequency band.
- a subset of the subframes (e.g., DL subframes) in a radio frame may be used for DL transmissions and another subset of the subframes (e.g., UL subframes) in the radio frame may be used for UL transmissions.
- each DL or UL subframe may have pre-defined regions for transmissions of reference signals, control information, and data.
- Reference signals are predetermined signals that facilitate the communications between the BSs 105 and the UEs 115.
- a reference signal can have a particular pilot pattern or structure, where pilot tones may span across an operational BW or frequency band, each positioned at a pre-defined time and a pre-defined frequency.
- a BS 105 may transmit cell specific reference signals (CRSs) and/or channel state information –reference signals (CSI-RSs) to enable a UE 115 to estimate a DL channel.
- CRSs cell specific reference signals
- CSI-RSs channel state information –reference signals
- a UE 115 may transmit sounding reference signals (SRSs) to enable a BS 105 to estimate a UL channel.
- Control information may include resource assignments and protocol controls.
- Data may include protocol data and/or operational data.
- the BSs 105 and the UEs 115 may communicate using self-contained subframes.
- a self-contained subframe may include a portion for DL communication and a portion for UL communication.
- a self-contained subframe can be DL-centric or UL-centric.
- a DL-centric subframe may include a longer duration for DL communication than for UL communication.
- a UL-centric subframe may include a longer duration for UL communication than for UL communication.
- the network 100 may be an NR network deployed over a licensed spectrum.
- the BSs 105 can transmit synchronization signals (e.g., including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) ) in the network 100 to facilitate synchronization.
- the BSs 105 can broadcast system information associated with the network 100 (e.g., including a master information block (MIB) , remaining system information (RMSI) , and other system information (OSI) ) to facilitate initial network access.
- MIB master information block
- RMSI remaining system information
- OSI system information
- the BSs 105 may broadcast the PSS, the SSS, and/or the MIB in the form of synchronization signal blocks (SSBs) over a physical broadcast channel (PBCH) and may broadcast the RMSI and/or the OSI over a physical downlink shared channel (PDSCH) .
- PBCH physical broadcast channel
- PDSCH physical downlink shared channel
- a UE 115 attempting to access the network 100 may perform an initial cell search by detecting a PSS from a BS 105.
- the PSS may enable synchronization of period timing and may indicate a physical layer identity value.
- the UE 115 may then receive a SSS.
- the SSS may enable radio frame synchronization, and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell.
- the PSS and the SSS may be located in a central portion of a carrier or any suitable frequencies within the carrier.
- the UE 115 may receive a MIB.
- the MIB may include system information for initial network access and scheduling information for RMSI and/or OSI.
- the UE 115 may receive RMSI and/or OSI.
- the RMSI and/or OSI may include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource set (CORESET) for physical downlink control channel (PDCCH) monitoring, physical UL control channel (PUCCH) , physical UL shared channel (PUSCH) , power control, and SRS.
- RRC radio resource control
- the UE 115 can perform a random access procedure to establish a connection with the BS 105.
- the random access procedure may be a four-step random access procedure.
- the UE 115 may transmit a random access preamble and the BS 105 may respond with a random access response.
- the random access response (RAR) may include a detected random access preamble identifier (ID) corresponding to the random access preamble, timing advance (TA) information, a UL grant, a temporary cell-radio network temporary identifier (C-RNTI) , and/or a backoff indicator.
- ID detected random access preamble identifier
- TA timing advance
- C-RNTI temporary cell-radio network temporary identifier
- the UE 115 may transmit a connection request to the BS 105 and the BS 105 may respond with a connection response.
- the connection response may indicate a contention resolution.
- the random access preamble, the RAR, the connection request, and the connection response can be referred to as message 1 (MSG1) , message 2 (MSG2) , message 3 (MSG3) , and message 4 (MSG4) , respectively.
- the random access procedure may be a two-step random access procedure, where the UE 115 may transmit a random access preamble and a connection request in a single transmission and the BS 105 may respond by transmitting a random access response and a connection response in a single transmission.
- the UE 115 and the BS 105 can enter a normal operation stage, where operational data may be exchanged.
- the BS 105 may schedule the UE 115 for UL and/or DL communications.
- the BS 105 may transmit UL and/or DL scheduling grants to the UE 115 via a PDCCH.
- the scheduling grants may be transmitted in the form of DL control information (DCI) .
- the BS 105 may transmit a DL communication signal (e.g., carrying data) to the UE 115 via a PDSCH according to a DL scheduling grant.
- the UE 115 may transmit a UL communication signal to the BS 105 via a PUSCH and/or PUCCH according to a UL scheduling grant.
- the BS 105 may communicate with a UE 115 using hybrid automatic repeat request (HARQ) techniques to improve communication reliability, for example, to provide an ultra-reliable low-latency communication (URLLC) service.
- the BS 105 may schedule a UE 115 for a PDSCH communication by transmitting a DL grant in a PDCCH.
- the BS 105 may transmit a DL data packet to the UE 115 according to the schedule in the PDSCH.
- the DL data packet may be transmitted in the form of a transport block (TB) . If the UE 115 receives the DL data packet successfully, the UE 115 may transmit a HARQ acknowledgement (ACK) to the BS 105.
- HARQ hybrid automatic repeat request
- the UE 115 may transmit a HARQ negative-acknowledgement (NACK) to the BS 105.
- NACK negative-acknowledgement
- the BS 105 may retransmit the DL data packet to the UE 115.
- the retransmission may include the same coded version of DL data as the initial transmission.
- the retransmission may include a different coded version of the DL data than the initial transmission.
- the UE 115 may apply soft-combining to combine the encoded data received from the initial transmission and the retransmission for decoding.
- the BS 105 and the UE 115 may also apply HARQ for UL communications using substantially similar mechanisms as the DL HARQ.
- the network 100 may operate over a system BW or a component carrier (CC) BW.
- the network 100 may partition the system BW into multiple bandwidth parts (BWPs) (e.g., portions) .
- BWPs bandwidth parts
- a BS 105 may dynamically assign a UE 115 to operate over a certain BWP (e.g., a certain portion of the system BW) .
- the assigned BWP may be referred to as the active BWP.
- the UE 115 may monitor the active BWP for signaling information from the BS 105.
- the BS 105 may schedule the UE 115 for UL or DL communications in the active BWP.
- a BS 105 may assign a pair of BWPs within the CC to a UE 115 for UL and DL communications.
- the BWP pair may include one BWP for UL communications and one BWP for DL communications.
- the network 100 may operate over a shared channel, which may include shared frequency bands or unlicensed frequency bands.
- the network 100 may be an NR-unlicensed (NR-U) network.
- the BSs 105 and the UEs 115 may be operated by multiple network operating entities. To avoid collisions, the BSs 105 and the UEs 115 may employ a listen-before-talk (LBT) procedure to monitor for transmission opportunities (TXOPs) in the shared channel.
- LBT listen-before-talk
- TXOPs transmission opportunities
- a transmitting node e.g., a BS 105 or a UE 115
- the transmitting node may refrain from transmitting in the channel.
- the LBT may be based on energy detection. For example, the LBT results in a pass when signal energy measured from the channel is below a threshold. Conversely, the LBT results in a failure when signal energy measured from the channel exceeds the threshold.
- the LBT may be based on signal detection. For example, the LBT results in a pass when a channel reservation signal (e.g., a predetermined preamble signal) is not detected in the channel.
- a channel reservation signal e.g., a predetermined preamble signal
- the network 100 may operate over a high frequency band, for example, in a frequency range 1 (FR1) band or a frequency range 2 (FR2) band.
- FR1 may refer to frequencies in the sub-6 GHz range and FR2 may refer to frequencies in the mmWave range.
- the BSs 105 and the UEs 115 may communicate with each other using directional beams. For instance, a BS 105 may transmit SSBs by sweeping across a set of predefined beam directions and may repeat the SSB transmissions at a certain time interval in the set of beam directions to allow a UE 115 to perform initial network access.
- NTN resource 105b it may transmit SSBs on each of its beams at scheduled times, even if the beams do not steer.
- each beam and its corresponding characteristics may be identified by a beam index.
- each SSB may include an indication of a beam index corresponding to the beam used for the SSB transmission.
- the UE 115 may determine signal measurements, such as reference signal received power (RSRP) and/or reference signal received quality (RSRQ) , for the SSBs at the different beam directions and select a best DL beam.
- the UE 115 may indicate the selection by transmitting a physical random access channel (PRACH) signal (e.g., MSG1) using PRACH resources associated with the selected beam direction.
- PRACH physical random access channel
- the SSB transmitted in a particular beam direction or on a particular beam may indicate PRACH resources that may be used by a UE 115 to communicate with the BS 105 in that particular beam direction.
- the UE 115 may complete the random access procedure (e.g., the 4-step random access or the 2-step random access) and proceed with network registration and normal operation data exchange with the BS 105.
- the initially selected beams may not be optimal or the channel condition may change, and thus the BS 105 and the UE 115 may perform a beam refinement procedure to refine a beam selection.
- BS 105 may transmit CSI-RSs by sweeping narrower beams over a narrower angular range and the UE 115 may report the best DL beam to the BS 105.
- the BS 105 may apply a higher gain, and thus may provide a better performance (e.g., a higher signal-noise-ratio (SNR) ) .
- the channel condition may degrade and/or the UE 115 may move out of a coverage of an initially selected beam, and thus the UE 115 may detect a beam failure condition.
- the UE 115 may perform beam handover.
- the network 100 may be an IoT network and the UEs 115 may be IoT nodes, such as smart printers, monitors, gaming nodes, cameras, audio-video (AV) production equipment, industrial IoT devices, and/or the like.
- the transmission payload data size of an IoT node typically may be relatively small, for example, in the order of tens of bytes.
- the network 100 may be a massive IoT network serving tens of thousands of nodes (e.g., UEs 115) over a high frequency band, such as a FR1 band or a FR2 band.
- FIG. 2 is a timing diagram illustrating a radio frame structure 200 according to some aspects of the present disclosure.
- the radio frame structure 200 may be employed by BSs such as the BSs 105 and UEs such as the UEs 115 in a network such as the network 100 for communications.
- the BS may communicate with the UE using time-frequency resources configured as shown in the radio frame structure 200.
- the x-axes represent time in some arbitrary units and the y-axes represent frequency in some arbitrary units.
- the transmission frame structure 200 includes a radio frame 201.
- the duration of the radio frame 201 may vary depending on the aspects. In an example, the radio frame 201 may have a duration of about ten milliseconds.
- the radio frame 201 includes M number of slots 202, where M may be any suitable positive integer. In an example, M may be about 10.
- Each slot 202 includes a number of subcarriers 204 in frequency and a number of symbols 206 in time.
- the number of subcarriers 204 and/or the number of symbols 206 in a slot 202 may vary depending on the aspects, for example, based on the channel bandwidth, the subcarrier spacing (SCS) , and/or the cyclic prefix (CP) .
- One subcarrier 204 in frequency and one symbol 206 in time forms one resource element (RE) 212 for transmission.
- a resource block (RB) 210 is formed from a number of consecutive subcarriers 204 in frequency and a number of consecutive symbols 206 in time.
- a BS may schedule a UE (e.g., UE 115 in FIG. 1) for UL and/or DL communications at a time-granularity of slots 202 or mini-slots 208.
- Each slot 202 may be time-partitioned into K number of mini-slots 208.
- Each mini-slot 208 may include one or more symbols 206.
- the mini-slots 208 in a slot 202 may have variable lengths. For example, when a slot 202 includes N number of symbols 206, a mini-slot 208 may have a length between one symbol 206 and (N-1) symbols 206.
- a mini-slot 208 may have a length of about two symbols 206, about four symbols 206, or about seven symbols 206.
- the BS may schedule UE at a frequency-granularity of a RB 210 (e.g., including about 12 subcarriers 204) .
- FIG. 3 illustrates a process of starting from an SSB to obtain the information about an initial downlink BWP and an initial uplink BWP part.
- the SSB includes a PBCH that carries MIB.
- a UE that receives the SSB decodes the SSB to acquire the MIB.
- the UE then parses the contents of the MIB, which point to a CORESET#0.
- the CORESET #0 includes a Physical Downlink Control Channel (PDCCH) and the PDCCH schedules system information block 1 (SIB1) on a PDSCH, and the SIB1 has information elements to identify an initial downlink BWP and an initial uplink BWP.
- PDCH Physical Downlink Control Channel
- SIB1 system information block 1
- the UE parses the contents of the SIB1, finds its initial downlink BWP and its initial uplink BWP and then uses the initial downlink BWP and uplink BWP to communicate with the BS for further configuration. For instance, the UE may communicate with the BS to be assigned a dedicated BWP on a particular beam for data transmission.
- the UE may communicate with the BS to be assigned a dedicated BWP on a particular beam for data transmission.
- some aspects of the disclosure may use a different MIB, a different CORESET #0, or a different SIB1.
- the SIB1 also identifies parameters relevant to numerology, such as subcarrier spacing and cyclic prefix.
- FIG. 4 is a table illustrating a variety of example numerologies that may be applied in one or more implementations.
- each column provides a different numerology, where a numerology includes a set of parameters for communication between a UE and a base station.
- the first row designates a parameter or numerology (u) , which may change among the different columns.
- u subcarrier spacing
- the set of numerologies depicted in the table of Figure 4 assumes a formula where subcarrier spacing (SCS) is equal to 15*2 u KHz.
- SCS subcarrier spacing
- the second and third rows display symbol duration and cyclic prefix (CP) in microseconds.
- the fourth row is total symbol duration in microseconds, and it equals the sum of the second and third rows.
- the fifth row provides a total number of OFDM symbols per slot.
- the column corresponding to numerology -1 has seven OFDM symbols per slot, whereas the column corresponding to numerology -1B has 14 OFDM symbols per slot.
- Traditional LTE numerologies include 14 OFDM symbols per slot.
- other numbers of OFDM symbols per slot are being considered, such as 7 (as in numerology -1) , 12 (as in numerology 1 ECP) , or 10 (as in numerology 2 e ECP) .
- ATG applications propagation delay due to reflection off of tall buildings or mountains may be as high as 8.33 ⁇ s.
- the propagation delay of ATG applications may be significantly more than that expected from NTN applications or terrestrial applications.
- Some implementations described herein include a cyclic prefix that is equal to or greater than 8.33 ⁇ s to accommodate the propagation delay that might be expected in some ATG applications.
- Another issue in ATG applications might be Doppler effect. For instance, at 700 MHz, a maximum line of sight Doppler effect might be as large as 0.77 kHz. As center frequency increases, the line of sight Doppler effect might increase more than proportionally.
- a UE or a base station may have hardware and software capable of compensating for Doppler effect that is as high as about 10%of the SCS.
- Some UEs or base stations may include better or poorer capability, and this is just an example. Nevertheless, for implementations assuming compensation abilities exist for up to 10%of SCS, then in a numerology using 700 MHz, an SCS of 7.5 kHz or greater would be desirable.
- an SCS of 30 kHz or 60 kHz would be desirable, and in a numerology using 4.8 GHz as a center frequency, an SCS equal to or greater than 60 kHz would be desirable.
- numerology -1 may have ample SCS and CP at 700 MHz, that center frequency may not provide a desired amount of bandwidth for an ATG UE that is built for 1 GHz or more bandwidth.
- numerologies 3 and 4 may be best reserved for millimeter wave applications, though millimeter wave may experience attenuation that makes it unsuitable for the long distances covered by an ATG base station cell.
- numerology 1 ECP which has an SCS of 30 kHz and a cyclic prefix of 8.33 ⁇ s.
- Numerology 1 ECP may be used with 3.5 GHz, thereby providing SCS of 30 kHz and CP of 8.33 ⁇ s. Those parameters may provide acceptable performance in an ATG application, considering propagation delay, Doppler effect, and expected attenuation.
- numerology 2 eECP may be used with either 3.5 GHz or 4.8 GHz as a center frequency to provide SCS of 60 kHz and CP of 8.33 ⁇ s. Once again, these parameters may provide acceptable performance in an ATG application.
- the numerologies including “ECP” refer to an extended CP, which is accomplished by reducing a number of OFDM symbols per slot. Disadvantages associated with ECP numerologies include a reduction in efficiency due to the relative length of the CP versus the total symbol duration as well as mismatch with traditional numerologies having 14 symbols per OFDM slot. However, in some applications, the disadvantages of those numerologies may be outweighed by the advantages. In fact, for any given application, an engineer may pick a numerology for use based on a variety of factors. ATG applications present their own special considerations, propagation delay and Doppler effect being among them, which makes them different from other applications, such as a NTN and car-based terrestrial.
- traditional LTE numerologies include 14 OFDM symbols per slot.
- the number of OFDM symbols allow different emitters to coexist more easily.
- numerology -1 it has seven OFDM symbols per slot, but it aligns with traditional numerologies including 14 OFDM symbols per slot since 14 is a multiple of seven.
- the other numerologies in the table of Figure 4 may include 12 OFDM symbols per slot or 10 symbols per slot in order to accommodate a larger CP. Since neither 10 nor 12 are a multiple of seven, such numerologies create misalignment when coexisting with other applications using seven or 14 OFDM symbols per slot.
- ATG applications adopting a numerology using 10 or 12 (or some other number of OFDM symbols per slot) may cause incrementally more interference with terrestrial UEs.
- Figure 4 describes different numerologies that may be used in ATG applications, other options may exist as well.
- OFDM waveforms include orthogonal time frequency space (OTFS) , direct Fourier transform spread OFDM (DFT-s-OFDM) , single carrier waveform, CDMA, GSM.
- OTFS is a particular case of time frequency spreading, and other time frequency spreading waveforms may be considered for use in various implementations as well.
- OTFS may be implemented in some ATG applications due to various advantageous features.
- OTFS may be used with any appropriate subcarrier spacing, such as 30 kHz or 60 kHz. Therefore, OTFS may provide acceptable performance when Doppler effect is expected to be relatively high.
- OTFS may omit using a CP, which may increase its spectral efficiency compared with OFDM waveforms having a larger CP.
- OTFS does have other concerns, such as the use of more complex receivers to account for inter-symbol interference in the time domain. While more complex receivers may be acceptable for use in projects that are less cost-sensitive, more cost-sensitive projects may be less likely to adopt the complex receivers associated with OTFS. Nevertheless, as time goes on, the cost of hardware and software capable of communicating using OTFS may decrease, thereby making OTFS more acceptable to general aviation. In the meantime, OTFS receivers may be more likely to be adopted by commercial and governmental aircraft.
- OTFS may be desirable for use during some flight scenarios. For instance, OTFS decoding latency may be higher than in OFDM because of the increased complexity of decoding in OTFS. OTFS may be a desirable option to choose when the Doppler effect is high, such as when an aircraft is en route. However, OFDM with its lower latency may be desirable when the Doppler effect is lower, such as during takeoff and landing. Accordingly, some ATG systems may be capable of switching between waveforms as appropriate.
- Different waveforms may cause interference.
- a terrestrial UE using OFDM for its downlink it may experience increased interference from an uplink signal from an ATG UE using OTFS both because of the high power expected to be used by the ATG UE as well as the difference in time domain and frequency domain properties present in the OTFS waveform.
- OTFS may include a shorter symbol duration relative to OFDM, and that unmatched symbol alignment may increase interference.
- numerologies with non-aligning numbers of symbols in a slot may be expected to cause increased interference
- an OTFS waveform spreads data over both the time and frequency domains and, thus, has increased non-alignment issues when interfering with an OFDM downlink.
- ATG applications may increase use of other waveforms, such as time frequency spreading and others, terrestrial UEs may expect to see interference from those sources.
- various ATG applications may experience propagation delays significantly different from those experienced by terrestrial UEs, and that difference in timing alignment may further increase interference experienced by terrestrial UEs.
- FIG. 5 is an illustration of an example wireless communication network according to one implementation.
- Figure 5 is offered to illustrate coexistence of an ATG BS 105g with a plurality of terrestrial BSs 105d, 105e.
- Terrestrial BSs 105d may be substantially the same as the terrestrial BS 105d of Figure 1.
- the UEs 115a, 115b may be the same as or similar to UEs 115a, 115b of Figure 1.
- Terrestrial BS 105e may also be the same as or similar to any of the BSs 105 of Figure 1
- UEs 115o, 115p may also be the same as or similar to any of the BSs of Figure 1.
- ATG BS 105g may have a backhaul connection with either one or both of the terrestrial BSs 105d, 105e.
- ATG BS 105g may be implemented in any appropriate manner, although in one example it has antennas that are directed upward for better reception by the ATG UEs 115l-n.
- the UEs 115l-n may include hardware mounted to a bottom of an aircraft to facilitate transmission and reception with the antennas of ATG BS 105g.
- ATG BS 105g may communicate using greater power than would traditionally be used by any of the terrestrial BSs 105d, 105e.
- the greater power allows ATG BS 105g to provide transmission and reception over a large cell 501, which in this example is shown as extending up to 300 km.
- the scope of implementations includes any appropriate size of cell 501, as 300 km is merely one example.
- the ATG BSs 115l-n may also transmit using a higher power than would traditionally be used with any of the terrestrial UEs 115.
- FIG. 5 shows that the terrestrial cells 502, 503 may be encompassed by the large area of ATG cell 501.
- ATG cell 501 may encompass more or fewer terrestrial cells, and some terrestrial cells may be partially within and partially without cell 501.
- the two terrestrial cells 502, 503 are shown encompassed by ATG cell 501 for ease of illustration, and it is understood that in some applications an example ATG cell 501 may encompass tens or even hundreds of terrestrial cells within a 200 km or 300 km radius.
- ATG communications and terrestrial NR are frequency division multiplexing, although that may suffer from low spectral efficiency in some instances.
- Another more spectral-efficient way to allow a non-orthogonal use of radio frequencies among ATG assets and terrestrial assets is OTFS, which may cause other issues to arise. For instance, spectral efficiency may be low at higher frequencies (e.g., 4.8 GHz) due to larger Doppler effect and propagation delay.
- Various implementations herein propose to use NR techniques with different waveforms than OFDM in order to achieve a higher spectral efficiency considering large Doppler effect and delays that might be expected in ATG applications. In doing so, there may be interference, such as illustrated in Figure 5. Nevertheless, despite the potential for interference, the benefits of using different waveforms are evident. As noted above, some different waveforms, such as OTFS, may achieve a higher spectral efficiency considering large Doppler effect and delays that might be expected in ATG applications. Also, as noted above, OTFS may be a desirable option to choose when the Doppler effect is high, such as when an aircraft is en route, and, OFDM with its lower latency may be desirable when the Doppler effect is lower, such as during takeoff and landing.
- a terrestrial UE may be adapted according to the principles herein.
- a terrestrial UE may be configured to switch between different waveforms to increase reliability, to decrease power use, to avoid interference from another waveform, and/or the like.
- Figure 6 is an illustration of an example method 600 for using multiple waveforms by a UE.
- Method 600 may be performed by a UE, such as any of the UEs 115 of Figure 1 and 5.
- the UE may be a terrestrial UE or an ATG UE.
- the actions of method 600 are performed as the UE communicates with the BS, which may be any of the BSs 105 of Figure 1 and 5.
- the UE transmits information regarding its capabilities to a BS.
- the UE may be camping on the BS, or the transmitting may take place during an initial access procedure or later when user data is being transmitted.
- the capabilities refer to which waveforms may be supported by the UE, allowing the base station to schedule appropriate waveforms.
- some commercial aircraft may include robust UEs that may be able to support many waveforms.
- general aviation aircraft and terrestrial UEs may be less robust and may support a fewer number of waveforms.
- different kinds of UEs may have different kinds of capabilities and, thus, action 601 allows the UE to report its capabilities to the BS.
- a particular UE may report to the BS that various waveforms are available or preferred.
- Example waveforms include, but are not limited to, OFDM, OTFS, DFT-s-OFDM, single carrier waveform, CDMA, and GSM.
- various implementations also include the UE providing information regarding whether it supports dual connectivity carrier aggregation (DC-CA) .
- Carrier aggregation generally refers to the ability of carriers to be aggregated and transmitted in parallel to/from the same UE to allow for wider bandwidth and higher data rates.
- a UE capable of carrier aggregation may receive or transmit simultaneously on multiple component carriers (CCs) .
- CCs component carriers
- Dual connectivity refers to the ability of the UE to have simultaneous connectivity to multiple nodes within a radio access network and, thus, DC-CA may provide the ability for UE to access two different CCs each using a different waveform. This is described in more detail with respect to actions 602-604.
- An action 602 the UE receives and processes configuration information from the base station, where the configuration information is based at least in part on the capability of the first UE. For instance, once the BS is aware of the capabilities of the UE, then it may determine combinations of waveforms to be assigned or scheduled to the UE.
- the BS determines to configure the UE so that different BWPs are associated with different waveforms. So, for instance, the BS may determine a configuration that looks like: BWP#0-OFDM, BWP#1-DFT-s-OFDM, BWP#2-Time-Freq-Spreading, BWP#3-OTFS.
- BWP#0OFDM BWP#0-OFDM
- BWP#1-DFT-s-OFDM BWP#2-Time-Freq-Spreading
- BWP#3-OTFS BWP#3-OTFS.
- a UE may support a fewer number of waveforms, such as only OFDM and single carrier or OFDM and DFT-s-OFDM.
- the BS may determine a configuration that uses any combination of BWPs to support multiple waveforms according to the capability of the UE.
- multiple BWPs may be assigned to a same waveform, while other BWPs are assigned to one or more other waveforms.
- the scope of implementations does not exclude the possibility of a combination of waveforms using fewer than four individual waveforms.
- the BS determines to configure the UE so that different CCs are assigned to different waveforms. For example, a first CC may be assigned to OFDM, and a 2 nd CC may be assigned to OTFS.
- a first CC may be assigned to OFDM
- a 2 nd CC may be assigned to OTFS.
- this is just an example, and the scope of implementations is not limited to any specific combination of waveforms to be assigned to different CCs. In fact, any appropriate combination of different waveforms may be used according to the capabilities of the UE.
- assigning different CCs to different waveforms may assume that at action 601 the UE indicated that it supports DC-CA.
- the configuration information of action 602 may be included in any appropriate control signal. For instance, assigning different BWPs to different waveforms may be accomplished using RRC. Additionally, the UE may be scheduled with an updated waveform using DCI to associate a BWP to a waveform or to switch between BWPs. Also, switching between BWPs may be performed semi-persistently according to RRC signaling.
- the UE communicates with the BS using the first waveform according to the configuration information.
- the UE is configured to use different waveforms with different BWPs.
- the UE may communicate with the UE using the first BWP and using the first waveform.
- the UE is configured to use different waveforms with different CCs.
- the UE may communicate with the UE using the first CC and using the first waveform.
- the UE communicates with the BS using the second waveform according to the configuration information.
- switching between different waveforms may be performed dynamically or semi-persistently.
- the BS may use DCI to schedule the UE to switch from a first BWP to a second BWP, thereby switching between waveforms.
- some implementations may include DCI having a BWP identifier in it. Switching between different BWPs may also be indicated semi-persistently using RRC.
- the scope of implementations is not limited to any particular control signaling, as any appropriate control signaling to switch between BWPs and/or waveforms may be used.
- OFDM may provide good performance, especially with respect to latency, during takeoff and landing
- OTFS may provide better spectral efficiency and Doppler performance when an aircraft is en route.
- Some implementations may include the BS causing the UE to switch between OFDM and OTFS as the aircraft transitions between takeoff and being en route or may cause the UE to switch between OTFS and OFDM as the aircraft transitions between being en route and landing. Implementations described herein allow the aircraft to switch between waveforms by switching between BWPs.
- switching between BWPs may include using configuration information, such as RRC parameters and DCI.
- the configuration information discussed above at 601 may be applied at actions 603-604 to affect a switch between BWPs.
- the UE may support DC-CA and, thus, may be able to access both CCs at the same time.
- the BS may then use one CC more heavily during takeoff and landing and the other CC more heavily when the aircraft is en route.
- different RRC parameters and/or DCI fields may support multiple waveforms, and each CC or BWP may include different configurations for different waveforms.
- Various embodiments may use DCI to tell the UE of a schedule of waveforms. In this example, instead of switching between BWPs and component carriers, each BWP or component carrier may be switched between waveforms.
- Various embodiments may indicate waveforms in semi-persistent scheduling (e.g., RRC) or DCI. When implemented within the method of Figure 6, such ability may allow the UE to switch between waveforms while continuing to use a same BWP or CC according to scheduling.
- method 600 may further include the base station configuring the UE to perform rate matching with respect to an additional and different waveform.
- the additional or different waveform may be associated with another UE or another base station, and the base station may configure the UE for rate matching by providing an RRC parameter or other appropriate information. Rate matching is described in more detail with respect to Figure 8.
- PDCCH may only include OFDM in some instances because PDCCH does not require as high throughput as PDSCH/PUSCH/PUCCH. Also, PDCCH may not include enough symbols to be spread using OTFS in some implementations.
- Figure 7 is an illustration of an example method 700 for using multiple waveforms by a UE.
- Method 700 may be performed by a UE, such as any of the UEs 115 of Figure 1 and 5.
- the UE may be a terrestrial UE or an ATG UE.
- the actions of method 700 are performed as the UE communicates with the BS, which may be any of the BSs 105 of Figure 1 and 5.
- a BS may have a higher beamforming capability than does a UE.
- the base station may include enhanced transmitting beamforming capability due to having a more robust antenna array.
- the UE even an ATG UE, may as a default use omnidirectional antennas with weaker beamforming capability.
- the result is that multipath effects may be asymmetrical as to uplink and downlink, so there may be greater multipath issues for uplink communications than for downlink communications.
- Method 700 uses separate waveforms for uplink and downlink to address this disparity.
- the ATG application uses OFDM on the downlink and uses OTFS on the uplink.
- the uplink may be expected to be affected by multipath
- the time and spectrum spreading of OTFS may ameliorate the effects of multipath on the uplink communications, and the system may still take advantage of the low latency of OFDM on the downlink.
- this example is given with respect to an ATG application, it is noted that the scope of implementations is not limited to ATG applications. Rather, the principles described herein may be applied to other applications, such as terrestrial applications.
- the BS receives and processes configuration information specifying uplink communications using OTFS or a single carrier waveform and specifying downlink communication using an OTFS waveform.
- the configuration information may specify the uplink and downlink communications according to the different waveforms using any appropriate control signal, such as RRC or DCI.
- the UE communicates with the base station using the OTFS waveform or single carrier waveform in uplink according to the configuration information.
- the UE communicates with the base station using the OFDM waveform in downlink according to the configuration information.
- the switch from waveform to waveform between actions 702 and 703 may be scheduled semi-persistently (e.g., by RRC) or dynamically (e.g., by DCI) .
- the UE may be configured to operate either in frequency division duplexing (FDD) mode or TDD mode with a particular CC.
- FDD frequency division duplexing
- the BS may determine an appropriate gap time between the uplink and the downlink to ensure overall time domain alignment. For instance, a time slot in OTFS may be different compared to a time slot in OFDM. So the two different waveforms may not be time domain aligned without the use of a gap time.
- FIG. 8 is an illustration of an example method 800 for rate matching by a UE.
- Method 800 may be performed by a UE, such as any of the UEs 115 of Figure 1 and 5.
- the UE may be a terrestrial UE or an ATG UE.
- the actions of method 800 are performed as the UE communicates with the BS, which may be any of the BSs 105 of Figure 1 and 5.
- rate matching may include a process of sizing and/or modulating data to fit into a particular block of time-frequency elements (such as available resource elements within a time frame, such as a slot, according to embodiments of the present disclosure) .
- rate matching may include sizing and/or modulating the contents of various resource elements on an uplink signal or a downlink signal so as to reduce misalignment or interference with respect to signals of another UE or another BS.
- a UE using OTFS may experience interference by an OFDM source that is non-aligned (or vice versa) .
- Various implementations herein configure a UE to rate match around signals associated with waveforms different from a waveform associated with a currently active BWP of the UE.
- the base station transmits RRC parameters to the UE, where those RRC parameters describe the other waveform.
- the base station may be programmed so when it performs that configuration it also additionally provides the RRC parameters associated with expected interference from another waveform.
- some symbols may be only partially affected by the interfering signal, and partially affected symbols may also be rate match around. However, in an instance in which the impact on a partially affected symbol is only within a cyclic prefix of the affected symbol, the UE may be configured to refrain from rate matching around.
- the UE communicates with the BS using a first waveform. Examples of waveforms are given above, and any appropriate waveform may be used.
- the UE receives and processes configuration information from the base station specifying a parameter for a second waveform.
- the base station may configure the UE by transmitting RRC parameters that are associated with a different waveform. For example, if the UE has an active BWP and is using an OFDM waveform, then the RRC parameters may be associated with an OTFS waveform or other waveform different from OFDM.
- the UE In response to the configuration information, the UE then performs rate matching with respect to the second waveform. Of course, if a symbol is only affected within its CP, then the UE may refrain from rate matching at least for that symbol. However, the UE may still perform rate matching with respect to other affected symbols.
- the BS may receive information regarding UE capabilities and then provide appropriate configuration information, such as described above with respect to Figures 6-8.
- Various implementations may provide one or more advantages. For instance, in implementations that jointly support multiple waveforms by the UE, then the UE may take advantage of a first waveform providing more robust operation with respect to Doppler effect in timing alignment when appropriate and then switching to another waveform to take advantage of decreased latency when appropriate. By assigning a particular waveform to either a BWP or a CC, then switching between waveforms may be performed by switching between BWPs or CCs. Similarly, by using separate waveforms for the uplink and downlink, a UE may take advantage of a first waveform more appropriate for beam forming by the BS and another waveform that is more appropriate for an omnidirectional antenna of the UE. Similarly, configuring the UE to perform rate matching may allow the UE to coexist with another UE using a different waveform.
- FIG. 9 is a block diagram of an exemplary UE 900 according to some aspects of the present disclosure.
- the UE 900 may be a UE 115 discussed above in FIGS. 1 and 5.
- the UE 900 may include a processor 902, a memory 904, a transceiver 910 including a modem subsystem 912 and a radio frequency (RF) unit 914, and one or more antennas 916. These elements may be in direct or indirect communication with each other, for example via one or more buses.
- RF radio frequency
- the processor 902 may include a central processing unit (CPU) , a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.
- the processor 902 may also be implemented as a combination of computing devices, e.g., 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.
- the memory 904 may include a cache memory (e.g., a cache memory of the processor 902) , random access memory (RAM) , magnetoresistive RAM (MRAM) , read-only memory (ROM) , programmable read-only memory (PROM) , erasable programmable read only memory (EPROM) , electrically erasable programmable read only memory (EEPROM) , flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory.
- memory 904 may include a ROM that stores a database, where that database includes information indicating capabilities, such as with respect to waveforms they can be used for PDSCH and waveforms that can be canceled.
- the memory 904 includes a non-transitory computer-readable medium.
- the memory 904 may store, or have recorded thereon, instructions 906.
- the instructions 906 may include instructions that, when executed by the processor 902, cause the processor 902 to perform the operations described herein with reference to the UEs 115 in connection with aspects of the present disclosure, for example, aspects of FIGS. 1-8.
- Instructions 906 may also be referred to as program code.
- the program code may be for causing a wireless communication device to perform these operations, for example by causing one or more processors (such as processor 902) to control or command the wireless communication device to do so.
- the terms “instructions” and “code” should be interpreted broadly to include any type of computer-readable statement (s) .
- instructions and code may refer to one or more programs, routines, sub-routines, functions, procedures, etc. “Instructions” and “code” may include a single computer-readable statement or many computer-readable statements.
- the transceiver 910 may include the modem subsystem 912 and the RF unit 914.
- the transceiver 910 can be configured to communicate bi-directionally with other devices, such as the BSs 105.
- the modem subsystem 912 may be configured to modulate and/or encode the data from the memory 904 and/or the beam module 908 according to a modulation and coding scheme (MCS) , e.g., a low-density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc.
- MCS modulation and coding scheme
- LDPC low-density parity check
- the RF unit 914 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.
- modulated/encoded data e.g., PUCCH control information, PRACH signals, PUSCH data, beam refinement request, beam switch command, reference signals
- modulated/encoded data e.g., PUCCH control information, PRACH signals, PUSCH data, beam refinement request, beam switch command, reference signals
- the RF unit 914 may be further configured to perform analog beamforming in conjunction with the digital beamforming.
- the modem subsystem 912 and the RF unit 914 may be separate devices that are coupled together at the UE 115 to enable the UE 115 to communicate with other devices.
- the RF unit 914 may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information) , to the antennas 916 for transmission to one or more other devices.
- the antennas 916 may further receive data messages transmitted from other devices.
- the antennas 916 may provide the received data messages for processing and/or demodulation at the transceiver 910.
- the transceiver 910 may provide the demodulated and decoded data (e.g., SSBs, PDCCH, PDSCH, beam switch command, CSI-RS resource configuration, CSI-RS reporting configuration, ) to the processor 902 processing.
- the antennas 916 may include multiple antennas of similar or different designs in order to sustain multiple transmission links.
- the RF unit 914 may configure the antennas 916.
- the UE 900 can include multiple transceivers 910 implementing different RATs (e.g., NR and LTE) .
- the UE 900 can include a single transceiver 910 implementing multiple RATs (e.g., NR and LTE) .
- the transceiver 910 can include various components, where different combinations of components can implement different RATs.
- FIG. 10 is a block diagram of an exemplary BS 1000 according to some aspects of the present disclosure.
- the BS 1000 may be a BS 105 in the network 100 as discussed above in FIGS. 1 and 5.
- the BS 1000 may include a processor 1002, a memory 1004, a transceiver 1010 including a modem subsystem 1012 and a RF unit 1014, and one or more antennas 1016. These elements may be in direct or indirect communication with each other, for example via one or more buses.
- the processor 1002 may have various features as a specific-type processor. For example, these may include a CPU, a DSP, an ASIC, a controller, a FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.
- the processor 1002 may also be implemented as a combination of computing devices, e.g., 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.
- the memory 1004 may include a cache memory (e.g., a cache memory of the processor 1002) , RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, a solid state memory device, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory.
- the memory 1004 may include a non-transitory computer-readable medium.
- the memory 1004 may store instructions 1006.
- the instructions 1006 may include instructions that, when executed by the processor 1002, cause the processor 1002 to cause the other components of the base station 1000 to communicate with the UE 1000, such as by transmitting SSBs, configurations, and the like, and actions described above with respect to FIGS. 1-8. Instructions 1006 may also be referred to as code, which may be interpreted broadly to include any type of computer-readable statement (s) as discussed above with respect to FIG. 9.
- the transceiver 1010 may include the modem subsystem 1012 and the RF unit 1014.
- the transceiver 1010 can be configured to communicate bi-directionally with other devices, such as the UEs 115 and/or another core network element.
- the modem subsystem 1012 may be configured to modulate and/or encode data according to a MCS, e.g., a LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc.
- the RF unit 1014 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.
- modulated/encoded data e.g., SSBs, RMSI, MIB, SIB, frame based equipment-FBE configuration, PRACH configuration PDCCH, PDSCH
- modulated/encoded data e.g., SSBs, RMSI, MIB, SIB, frame based equipment-FBE configuration, PRACH configuration PDCCH, PDSCH
- the RF unit 1014 may be further configured to perform analog beamforming in conjunction with the digital beamforming.
- the modem subsystem 1012 and/or the RF unit 1014 may be separate devices that are coupled together at the BS 105 to enable the BS 105 to communicate with other devices.
- the RF unit 1014 may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information) , to the antennas 1016 for transmission to one or more other devices.
- the antennas 1016 may be similar to the antennas of the BS 105 discussed above. This may include, for example, transmission of information to complete attachment to a network and communication with a camped UE 115 according to some aspects of the present disclosure.
- the antennas 1016 may further receive data messages transmitted from other devices and provide the received data messages for processing and/or demodulation at the transceiver 1010.
- the transceiver 1010 may provide the demodulated and decoded data (e.g., PUCCH control information, PRACH signals, PUSCH data) to the processor 1002 for processing.
- the antennas 1016 may include multiple antennas of similar or different designs in order to sustain multiple transmission links.
- the BS 1000 can include multiple transceivers 1010 implementing different RATs (e.g., NR and LTE) .
- the BS 1000 can include a single transceiver 1010 implementing multiple RATs (e.g., NR and LTE) .
- the transceiver 1010 can include various components, where different combinations of components can implement different RATs.
- a general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine.
- a processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) .
- the functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.
- “or” as used in a list of items indicates an inclusive 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 (i.e., A and B and C) .
- a method performed by a user equipment (UE) comprising:
- processing configuration information specifying communication using a first waveform in a first bandwidth part (BWP) or a first component carrier (CC) and a second waveform in a second BWP or a second CC, wherein the first waveform and the second waveform are different;
- BWP bandwidth part
- CC component carrier
- the configuration information comprises radio resource control (RRC) information.
- RRC radio resource control
- the base station reporting UE capability information to the base station, the UE capability information identifying the first waveform and the second waveform as available to the UE.
- the UE capability information identifying availability of dual connectivity carrier aggregation (DC-CA) .
- DC-CA dual connectivity carrier aggregation
- the further configuration information comprises an item selected from a list consisting of: DL control information (DCI) ; and a radio resource control (RRC) signal.
- DCI DL control information
- RRC radio resource control
- a user equipment comprising:
- a processor controlling the transceiver configured to:
- process configuration information specifying uplink communications using an orthogonal time frequency and space (OTFS) waveform or a single carrier waveform and specifying downlink communication using an orthogonal frequency division multiplexing (OFDM) waveform;
- OTFS orthogonal time frequency and space
- OFDM orthogonal frequency division multiplexing
- the configuration information comprises radio resource control (RRC) information.
- RRC radio resource control
- the processor is configured to communicate with the base station using the OTFS waveform and communicate with the base station using the OFDM waveform according to time domain duplexing (TDD) , further wherein the configuration information indicates a time gap between downlink and uplink.
- TDD time domain duplexing
- a user equipment comprising:
- the configuration information comprises radio resource control (RRC) information.
- RRC radio resource control
- the means for rate matching further includes means for omitting rate matching with respect to a symbol in the first waveform wherein only a cyclic prefix (CP) of the symbol is affected.
- CP cyclic prefix
- BWP bandwidth part
- CC component carrier
- UE user equipment
- UE user equipment
- DC-CA dual connectivity carrier aggregation
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Abstract
A method performed by a user equipment (UE) includes: processing configuration information specifying communication using a first waveform in a first bandwidth part (BWP) or a first component carrier (CC) and a second waveform in a second BWP or a second CC, wherein the first waveform and the second waveform are different; communicating with a base station using the first waveform according to the configuration information; and subsequent to using the first waveform, communicating with the base station using the second waveform according to the configuration information.
Description
Qiaoyu Li, Chao Wei, Yu Zhang, Hao Xu
This application relates to wireless communication systems, and more particularly to techniques to support multiple waveforms in user equipment (UE) .
INTRODUCTION
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . A wireless multiple-access communications system may include a number of base stations (BSs) , each simultaneously supporting communications for multiple communication devices, which may be otherwise known as user equipment (UE) .
To meet the growing demands for expanded mobile broadband connectivity, wireless communication technologies are advancing from the long term evolution (LTE) technology to a next generation new radio (NR) technology, which may be referred to as 5
th Generation (5G) . For example, NR is designed to provide a lower latency, a higher bandwidth or a higher throughput, and a higher reliability than LTE. NR is designed to operate over a wide array of spectrum bands, for example, from low-frequency bands below about 1 gigahertz (GHz) and mid-frequency bands from about 1 GHz to about 6 GHz, to high-frequency bands such as mmWave bands. NR is also designed to operate across different spectrum types, from licensed spectrum to unlicensed and shared spectrum. Spectrum sharing enables operators to opportunistically aggregate spectrums to dynamically support high-bandwidth services. Spectrum sharing can extend the benefit of NR technologies to operating entities that may not have access to a licensed spectrum.
NR technology may also make use of a variety of different base station and user equipment technologies to maintain communication at acceptable throughput rates. An example type of base station and user equipment technology includes air to ground (ATG) applications. An example of an ATG application includes a base station having antennas oriented generally upward communicating with an aircraft-based user equipment. ATG base stations may have large radio frequency (RF) footprints, e.g., a radius of hundreds of kilometers. By contrast, a typical terrestrial base station may have a footprint of only a few kilometers. Therefore, an ATG base station and an ATG UE may benefit from use of techniques to address issues such as increased time delay and Doppler effect, which may affect ATG applications more than terrestrial applications.
BRIEF SUMMARY OF SOME EXAMPLES
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.
For example, in an aspect of the disclosure, a method performed by a user equipment (UE) includes processing configuration information specifying communication using a first waveform in a first bandwidth part (BWP) or a first component carrier (CC) and a second waveform in a second BWP or a second CC, wherein the first waveform and the second waveform are different; communicating with a base station using the first waveform according to the configuration information; and subsequent to using the first waveform, communicating with the base station using the second waveform according to the configuration information.
In another aspect, a UE includes: a transceiver; and a processor controlling the transceiver, the processor configured to: process configuration information specifying uplink communications using an orthogonal time frequency and space (OTFS) waveform or a single carrier waveform and specifying downlink communication using an orthogonal frequency division multiplexing (OFDM) waveform; communicate with a base station using the OTFS waveform or the single carrier waveform in uplink according to the configuration information; and communicate with the base station using the OFDM waveform in downlink according to the configuration information.
In another aspect, a UE includes: means for communicating with a base station using a first waveform; means for processing configuration information from the base station specifying a parameter for a second waveform; and means for rate matching with respect to the second waveform, wherein the first waveform and the second waveform are different.
In another aspect, a non-transitory computer-readable medium having program code recorded thereon includes: code for processing configuration information specifying communication using a first waveform in a first bandwidth part (BWP) or a first component carrier (CC) and a second waveform in a second BWP or a second CC, wherein the first waveform and the second waveform are different; code for communicating with a base station using the first waveform according to the configuration information; and code for communicating with the base station using the second waveform according to the configuration information subsequent to using the first waveform.
Other aspects, features, and embodiments of the present disclosure will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary embodiments of the present disclosure in conjunction with the accompanying figures. While features of the present disclosure may be discussed relative to certain embodiments and figures below, all embodiments of the present disclosure can include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various embodiments of the disclosure discussed herein. In similar fashion, while exemplary embodiments may be discussed below as device, system, or method embodiments it should be understood that such exemplary embodiments can be implemented in various devices, systems, and methods.
FIG. 1 illustrates a wireless communication network according to some aspects of the present disclosure.
FIG. 2 illustrates a radio frame structure according to some aspects of the present disclosure.
FIG. 3 illustrates a block diagram of an example SSB, according to some aspects of the present disclosure.
FIG. 4 is an illustration of example numerologies according to some aspects of the present disclosure.
FIG. 5 is an illustration of an example relationship between an air to ground (ATG) cell and two different terrestrial cells, including illustrating interference among UEs, according to some aspects of the present disclosure.
FIG. 6 is an illustration of an example method according to some aspects of the present disclosure.
FIG. 7 is an illustration of an example method according to some aspects of the present disclosure.
FIG. 8 is an illustration of an example method according to some aspects of the present disclosure.
FIG. 9 is a block diagram of a user equipment (UE) according to some aspects of the present disclosure.
FIG. 10 is a block diagram of an exemplary base station (BS) according to some aspects of the present disclosure.
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 represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.
As described in more detail below, various implementations include methods of wireless communication, apparatuses, and non-transitory computer-readable media that provide support for using multiple waveforms, which may be applied to both terrestrial user equipment (UE) and air to ground (ATG) UEs. For instance, in one implementation, a base station configures a UE to use different waveforms with different respective bandwidth parts or component carriers. In another implementation, the base station may configure the UE to use different waveforms for uplink and downlink communications, respectively. In yet another implementation, the base station may configure the UE to perform rate matching around different waveforms. An advantage to using multiple waveforms is that a UE may benefit from increased robustness against Doppler effect and timing alignment issues, as explained in more detail below.
This disclosure relates generally to wireless communications systems, also referred to as wireless communications networks. 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, Global System for Mobile Communications (GSM) networks, 5
th Generation (5G) or new radio (NR) networks, as well as other communications networks. As described herein, the terms “networks” and “systems” may be used interchangeably.
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 are described in documents provided from an organization named “3
rd Generation Partnership Project” (3GPP) , and cdma2000 is described in documents from an organization named “3
rd Generation Partnership Project 2” (3GPP2) . These various radio technologies and standards are known or are being developed. For example, the 3
rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (3G) mobile phone specification. 3GPP long term evolution (LTE) is a 3GPP project which was aimed at improving the UMTS mobile phone standard. The 3GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices. The present disclosure is concerned with the evolution of wireless technologies from LTE, 4G, 5G, NR, and beyond with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces.
In particular, 5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. In order 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 (IoTs) with a ULtra-high density (e.g., ~1M nodes/km
2) , ultra-low complexity (e.g., ~10s 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 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
2) , extreme data rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates) , and deep awareness with advanced discovery and optimizations.
The 5G NR may be implemented to use optimized OFDM-based waveforms with scalable numerology and transmission time interval (TTI) ; having a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD) /frequency division duplex (FDD) design; and with advanced wireless technologies, such as massive multiple input, multiple output (MIMO) , robust millimeter wave (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 3GHz FDD/TDD implementations, subcarrier spacing (SCS) may occur with 15 kHz, for example over 5, 10, 20 MHz, and the like bandwidth (BW) . For other various outdoor and small cell coverage deployments of TDD greater than 3 GHz, subcarrier spacing may occur with 30 kHz over a 80/100 MHz BW. 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 BW. 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 BW.
The scalable numerology of the 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 may allow transmissions to start on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe design with uplink/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 /downlink that may be flexibly configured on a per-cell basis to dynamically switch between uplink (UL) and downlink (DL) to meet the current traffic needs.
FIG. 1 illustrates a wireless communication network 100 according to some aspects of the present disclosure. The network 100 may be a 5G network. The network 100 includes a number of base stations (BSs) 105 (individually labeled as 105a, 105b, 105c, 105d, 105e, and 105f) and other network entities. A BS 105 may be a station that communicates with UEs 115 and may also be referred to as an evolved node B (eNB) , a next generation eNB (gNB) , an access point, and the like. Each BS 105 may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to this particular geographic coverage area of a BS 105 and/or a BS subsystem serving the coverage area, depending on the context in which the term is used. The actions of FIG. 7 may be performed by any of BSs 105.
A BS 105 may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and/or other types of cell. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted 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 BS for a macro cell may be referred to as a macro BS. A BS for a small cell may be referred to as a small cell BS, a pico BS, a femto BS or a home BS. In the example shown in FIG. 1, the BSs 105b, 105d, and 105e may be regular macro BSs, while the BSs 105a and 105c may be macro BSs enabled with one of three dimension (3D) , full dimension (FD) , or massive MIMO. The BSs 105a and 105c may take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. The BS 105f may be a small cell BS which may be a home node or portable access point. A BS 105 may support one or multiple (e.g., two, three, four, and the like) cells.
The network 100 may support synchronous or asynchronous operation. For synchronous operation, the BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, the BSs may have different frame timing, and transmissions from different BSs may not be aligned in time.
The UEs 115 are dispersed throughout the wireless network 100, and each UE 115 may be stationary or mobile. A UE 115 may also be referred to as a terminal, a mobile station, a subscriber unit, a station, or the like. A UE 115 may be a cellular phone, a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, or the like. In one aspect, a UE 115 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, the UEs 115 that do not include UICCs may also be referred to as IoT devices or internet of everything (IoE) devices. The UEs 115a-115d are examples of mobile smart phone-type devices accessing network 100. A UE 115 may also be a machine specifically configured for connected communication, including machine type communication (MTC) , enhanced MTC (eMTC) , narrowband IoT (NB-IoT) and the like. The UEs 115e-115h are examples of various machines configured for communication that access the network 100. The UEs 115i-115k are examples of vehicles equipped with wireless communication devices configured for communication that access the network 100. A UE 115 may be able to communicate with any type of the BSs, whether macro BS, small cell, or the like. In FIG. 1, a lightning bolt (e.g., communication links) indicates wireless transmissions between a UE 115 and a serving BS 105, which is a BS designated to serve the UE 115 on the downlink (DL) and/or uplink (UL) , desired transmission between BSs 105, backhaul transmissions between BSs, or sidelink transmissions between UEs 115.
Figure 5 provides other examples of BSs 105 and UEs 115, and it is understood that those BSs 105 and UEs 115 operate the same as or similarly to those described with respect to Figure 1. For instance, Figure 5 illustrates an ATG BS 105g and three ATG UEs 115l-n. These additional assets are described in more detail below.
Now returning to Figure 1, in operation, the BSs 105a and 105c may serve the UEs 115a and 115b using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. The macro BS 105d may perform backhaul communications with the BSs 105a and 105c, as well as small cell, the BS 105f. The macro BS 105d may also transmit multicast services which are subscribed to and received by the 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.
The BSs 105 may also communicate with a core network. The core network may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs 105 (e.g., which may be an example of a gNB or an access node controller (ANC) ) may interface with the core network through backhaul links (e.g., NG-C, NG-U, etc. ) and may perform radio configuration and scheduling for communication with the UEs 115. In various examples, the BSs 105 may communicate, either directly or indirectly (e.g., through core network) , with each other over backhaul links (e.g., X1, X2, etc. ) , which may be wired or wireless communication links.
The network 100 may also support mission critical communications with ultra-reliable and redundant links for mission critical devices, such as the UE 115e, which may be a drone. Redundant communication links with the UE 115e may include links from the macro BSs 105d and 105e, as well as links from the small cell BS 105f. Other machine type devices, such as the UE 115f (e.g., a thermometer) , the UE 115g (e.g., smart meter) , and UE 115h (e.g., wearable device) may communicate through the network 100 either directly with BSs, such as the small cell BS 105f, and the macro BS 105e, or in multi-step-size configurations by communicating with another user device which relays its information to the network, such as the UE 115f communicating temperature measurement information to the smart meter, the UE 115g, which is then reported to the network through the small cell BS 105f. The network 100 may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such as vehicle-to-vehicle (V2V) , vehicle-to-everything (V2X) , cellular-V2X (C-V2X) communications between a UE 115i, 115j, or 115k and other UEs 115, and/or vehicle-to-infrastructure (V2I) communications between a UE 115i, 115j, or 115k and a BS 105. Additionally, BS 105b is shown as a non-terrestrial network (NTN) resource, such as a satellite that orbits the earth. In this example, BS 105b may include multiple antenna arrays, each array forming a relatively fixed beam. BS 105b may be configured as a single cell with multiple beams and BWPs, as explained in more detail below.
In some implementations, the network 100 utilizes OFDM-based waveforms for communications. An OFDM-based system may partition the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, bins, or the like. Each subcarrier may be modulated with data. In some instances, the subcarrier spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system BW. The system BW may also be partitioned into subbands. In other instances, the subcarrier spacing and/or the duration of TTIs may be scalable.
In some aspects, the BSs 105 can assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RB) ) for downlink (DL) and uplink (UL) transmissions in the network 100. DL refers to the transmission direction from a BS 105 to a UE 115, whereas UL refers to the transmission direction from a UE 115 to a BS 105. The communication can be in the form of radio frames. A radio frame may be divided into a plurality of subframes or slots, for example, about 10. Each slot may be further divided into mini-slots. In a FDD mode, simultaneous UL and DL transmissions may occur in different frequency bands. For example, each subframe includes a UL subframe in a UL frequency band and a DL subframe in a DL frequency band. In a TDD mode, UL and DL transmissions occur at different time periods using the same frequency band. For example, a subset of the subframes (e.g., DL subframes) in a radio frame may be used for DL transmissions and another subset of the subframes (e.g., UL subframes) in the radio frame may be used for UL transmissions.
The DL subframes and the UL subframes can be further divided into several regions. For example, each DL or UL subframe may have pre-defined regions for transmissions of reference signals, control information, and data. Reference signals are predetermined signals that facilitate the communications between the BSs 105 and the UEs 115. For example, a reference signal can have a particular pilot pattern or structure, where pilot tones may span across an operational BW or frequency band, each positioned at a pre-defined time and a pre-defined frequency. For example, a BS 105 may transmit cell specific reference signals (CRSs) and/or channel state information –reference signals (CSI-RSs) to enable a UE 115 to estimate a DL channel. Similarly, a UE 115 may transmit sounding reference signals (SRSs) to enable a BS 105 to estimate a UL channel. Control information may include resource assignments and protocol controls. Data may include protocol data and/or operational data. In some aspects, the BSs 105 and the UEs 115 may communicate using self-contained subframes. A self-contained subframe may include a portion for DL communication and a portion for UL communication. A self-contained subframe can be DL-centric or UL-centric. A DL-centric subframe may include a longer duration for DL communication than for UL communication. A UL-centric subframe may include a longer duration for UL communication than for UL communication.
In some aspects, the network 100 may be an NR network deployed over a licensed spectrum. The BSs 105 can transmit synchronization signals (e.g., including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) ) in the network 100 to facilitate synchronization. The BSs 105 can broadcast system information associated with the network 100 (e.g., including a master information block (MIB) , remaining system information (RMSI) , and other system information (OSI) ) to facilitate initial network access. In some instances, the BSs 105 may broadcast the PSS, the SSS, and/or the MIB in the form of synchronization signal blocks (SSBs) over a physical broadcast channel (PBCH) and may broadcast the RMSI and/or the OSI over a physical downlink shared channel (PDSCH) .
In some aspects, a UE 115 attempting to access the network 100 may perform an initial cell search by detecting a PSS from a BS 105. The PSS may enable synchronization of period timing and may indicate a physical layer identity value. The UE 115 may then receive a SSS. The SSS may enable radio frame synchronization, and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell. The PSS and the SSS may be located in a central portion of a carrier or any suitable frequencies within the carrier.
After receiving the PSS and SSS, the UE 115 may receive a MIB. The MIB may include system information for initial network access and scheduling information for RMSI and/or OSI. After decoding the MIB, the UE 115 may receive RMSI and/or OSI. The RMSI and/or OSI may include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource set (CORESET) for physical downlink control channel (PDCCH) monitoring, physical UL control channel (PUCCH) , physical UL shared channel (PUSCH) , power control, and SRS.
After obtaining the MIB, the RMSI and/or the OSI, the UE 115 can perform a random access procedure to establish a connection with the BS 105. In some examples, the random access procedure may be a four-step random access procedure. For example, the UE 115 may transmit a random access preamble and the BS 105 may respond with a random access response. The random access response (RAR) may include a detected random access preamble identifier (ID) corresponding to the random access preamble, timing advance (TA) information, a UL grant, a temporary cell-radio network temporary identifier (C-RNTI) , and/or a backoff indicator. Upon receiving the random access response, the UE 115 may transmit a connection request to the BS 105 and the BS 105 may respond with a connection response. The connection response may indicate a contention resolution. In some examples, the random access preamble, the RAR, the connection request, and the connection response can be referred to as message 1 (MSG1) , message 2 (MSG2) , message 3 (MSG3) , and message 4 (MSG4) , respectively. In some examples, the random access procedure may be a two-step random access procedure, where the UE 115 may transmit a random access preamble and a connection request in a single transmission and the BS 105 may respond by transmitting a random access response and a connection response in a single transmission.
After establishing a connection, the UE 115 and the BS 105 can enter a normal operation stage, where operational data may be exchanged. For example, the BS 105 may schedule the UE 115 for UL and/or DL communications. The BS 105 may transmit UL and/or DL scheduling grants to the UE 115 via a PDCCH. The scheduling grants may be transmitted in the form of DL control information (DCI) . The BS 105 may transmit a DL communication signal (e.g., carrying data) to the UE 115 via a PDSCH according to a DL scheduling grant. The UE 115 may transmit a UL communication signal to the BS 105 via a PUSCH and/or PUCCH according to a UL scheduling grant.
In some aspects, the BS 105 may communicate with a UE 115 using hybrid automatic repeat request (HARQ) techniques to improve communication reliability, for example, to provide an ultra-reliable low-latency communication (URLLC) service. The BS 105 may schedule a UE 115 for a PDSCH communication by transmitting a DL grant in a PDCCH. The BS 105 may transmit a DL data packet to the UE 115 according to the schedule in the PDSCH. The DL data packet may be transmitted in the form of a transport block (TB) . If the UE 115 receives the DL data packet successfully, the UE 115 may transmit a HARQ acknowledgement (ACK) to the BS 105. Conversely, if the UE 115 fails to receive the DL transmission successfully, the UE 115 may transmit a HARQ negative-acknowledgement (NACK) to the BS 105. Upon receiving a HARQ NACK from the UE 115, the BS 105 may retransmit the DL data packet to the UE 115. The retransmission may include the same coded version of DL data as the initial transmission. Alternatively, the retransmission may include a different coded version of the DL data than the initial transmission. The UE 115 may apply soft-combining to combine the encoded data received from the initial transmission and the retransmission for decoding. The BS 105 and the UE 115 may also apply HARQ for UL communications using substantially similar mechanisms as the DL HARQ.
In some aspects, the network 100 may operate over a system BW or a component carrier (CC) BW. The network 100 may partition the system BW into multiple bandwidth parts (BWPs) (e.g., portions) . A BS 105 may dynamically assign a UE 115 to operate over a certain BWP (e.g., a certain portion of the system BW) . The assigned BWP may be referred to as the active BWP. The UE 115 may monitor the active BWP for signaling information from the BS 105. The BS 105 may schedule the UE 115 for UL or DL communications in the active BWP. In some aspects, a BS 105 may assign a pair of BWPs within the CC to a UE 115 for UL and DL communications. For example, the BWP pair may include one BWP for UL communications and one BWP for DL communications.
In some aspects, the network 100 may operate over a shared channel, which may include shared frequency bands or unlicensed frequency bands. For example, the network 100 may be an NR-unlicensed (NR-U) network. The BSs 105 and the UEs 115 may be operated by multiple network operating entities. To avoid collisions, the BSs 105 and the UEs 115 may employ a listen-before-talk (LBT) procedure to monitor for transmission opportunities (TXOPs) in the shared channel. For example, a transmitting node (e.g., a BS 105 or a UE 115) may perform an LBT prior to transmitting in the channel. When the LBT passes, the transmitting node may proceed with the transmission. When the LBT fails, the transmitting node may refrain from transmitting in the channel. In an example, the LBT may be based on energy detection. For example, the LBT results in a pass when signal energy measured from the channel is below a threshold. Conversely, the LBT results in a failure when signal energy measured from the channel exceeds the threshold. In another example, the LBT may be based on signal detection. For example, the LBT results in a pass when a channel reservation signal (e.g., a predetermined preamble signal) is not detected in the channel.
In some aspects, the network 100 may operate over a high frequency band, for example, in a frequency range 1 (FR1) band or a frequency range 2 (FR2) band. FR1 may refer to frequencies in the sub-6 GHz range and FR2 may refer to frequencies in the mmWave range. To overcome the high path-loss at high frequency, the BSs 105 and the UEs 115 may communicate with each other using directional beams. For instance, a BS 105 may transmit SSBs by sweeping across a set of predefined beam directions and may repeat the SSB transmissions at a certain time interval in the set of beam directions to allow a UE 115 to perform initial network access. In the example of NTN resource 105b, it may transmit SSBs on each of its beams at scheduled times, even if the beams do not steer. In some instances, each beam and its corresponding characteristics may be identified by a beam index. For instance, each SSB may include an indication of a beam index corresponding to the beam used for the SSB transmission.
The UE 115 may determine signal measurements, such as reference signal received power (RSRP) and/or reference signal received quality (RSRQ) , for the SSBs at the different beam directions and select a best DL beam. The UE 115 may indicate the selection by transmitting a physical random access channel (PRACH) signal (e.g., MSG1) using PRACH resources associated with the selected beam direction. For instance, the SSB transmitted in a particular beam direction or on a particular beam may indicate PRACH resources that may be used by a UE 115 to communicate with the BS 105 in that particular beam direction. After selecting the best DL beam, the UE 115 may complete the random access procedure (e.g., the 4-step random access or the 2-step random access) and proceed with network registration and normal operation data exchange with the BS 105. In some instances, the initially selected beams may not be optimal or the channel condition may change, and thus the BS 105 and the UE 115 may perform a beam refinement procedure to refine a beam selection. For instance, BS 105 may transmit CSI-RSs by sweeping narrower beams over a narrower angular range and the UE 115 may report the best DL beam to the BS 105. When the BS 105 uses a narrower beam for transmission, the BS 105 may apply a higher gain, and thus may provide a better performance (e.g., a higher signal-noise-ratio (SNR) ) . In some instances, the channel condition may degrade and/or the UE 115 may move out of a coverage of an initially selected beam, and thus the UE 115 may detect a beam failure condition. Upon detecting a beam failure, the UE 115 may perform beam handover.
In some aspects, the network 100 may be an IoT network and the UEs 115 may be IoT nodes, such as smart printers, monitors, gaming nodes, cameras, audio-video (AV) production equipment, industrial IoT devices, and/or the like. The transmission payload data size of an IoT node typically may be relatively small, for example, in the order of tens of bytes. In some aspects, the network 100 may be a massive IoT network serving tens of thousands of nodes (e.g., UEs 115) over a high frequency band, such as a FR1 band or a FR2 band.
FIG. 2 is a timing diagram illustrating a radio frame structure 200 according to some aspects of the present disclosure. The radio frame structure 200 may be employed by BSs such as the BSs 105 and UEs such as the UEs 115 in a network such as the network 100 for communications. In particular, the BS may communicate with the UE using time-frequency resources configured as shown in the radio frame structure 200. In FIG. 2, the x-axes represent time in some arbitrary units and the y-axes represent frequency in some arbitrary units. The transmission frame structure 200 includes a radio frame 201. The duration of the radio frame 201 may vary depending on the aspects. In an example, the radio frame 201 may have a duration of about ten milliseconds. The radio frame 201 includes M number of slots 202, where M may be any suitable positive integer. In an example, M may be about 10.
Each slot 202 includes a number of subcarriers 204 in frequency and a number of symbols 206 in time. The number of subcarriers 204 and/or the number of symbols 206 in a slot 202 may vary depending on the aspects, for example, based on the channel bandwidth, the subcarrier spacing (SCS) , and/or the cyclic prefix (CP) . One subcarrier 204 in frequency and one symbol 206 in time forms one resource element (RE) 212 for transmission. A resource block (RB) 210 is formed from a number of consecutive subcarriers 204 in frequency and a number of consecutive symbols 206 in time.
In an example, a BS (e.g., BS 105 in FIG. 1) may schedule a UE (e.g., UE 115 in FIG. 1) for UL and/or DL communications at a time-granularity of slots 202 or mini-slots 208. Each slot 202 may be time-partitioned into K number of mini-slots 208. Each mini-slot 208 may include one or more symbols 206. The mini-slots 208 in a slot 202 may have variable lengths. For example, when a slot 202 includes N number of symbols 206, a mini-slot 208 may have a length between one symbol 206 and (N-1) symbols 206. In some aspects, a mini-slot 208 may have a length of about two symbols 206, about four symbols 206, or about seven symbols 206. In some examples, the BS may schedule UE at a frequency-granularity of a RB 210 (e.g., including about 12 subcarriers 204) .
FIG. 3 illustrates a process of starting from an SSB to obtain the information about an initial downlink BWP and an initial uplink BWP part. In this implementation, the SSB includes a PBCH that carries MIB. A UE that receives the SSB decodes the SSB to acquire the MIB. The UE then parses the contents of the MIB, which point to a CORESET# 0. The CORESET # 0 includes a Physical Downlink Control Channel (PDCCH) and the PDCCH schedules system information block 1 (SIB1) on a PDSCH, and the SIB1 has information elements to identify an initial downlink BWP and an initial uplink BWP. The UE parses the contents of the SIB1, finds its initial downlink BWP and its initial uplink BWP and then uses the initial downlink BWP and uplink BWP to communicate with the BS for further configuration. For instance, the UE may communicate with the BS to be assigned a dedicated BWP on a particular beam for data transmission. Of course, some aspects of the disclosure may use a different MIB, a different CORESET # 0, or a different SIB1. The SIB1 also identifies parameters relevant to numerology, such as subcarrier spacing and cyclic prefix.
FIG. 4 is a table illustrating a variety of example numerologies that may be applied in one or more implementations. In this example, each column provides a different numerology, where a numerology includes a set of parameters for communication between a UE and a base station. The first row designates a parameter or numerology (u) , which may change among the different columns. For instance, the set of numerologies depicted in the table of Figure 4 assumes a formula where subcarrier spacing (SCS) is equal to 15*2
uKHz. Thus, when u is equal to -1, then the SCS equals 7.5 kHz. Similarly, when u is equal to 0, then SCS equals 15 kHz, and when u is equal to 2, SCS equals 60KHz.
The second and third rows display symbol duration and cyclic prefix (CP) in microseconds. The fourth row is total symbol duration in microseconds, and it equals the sum of the second and third rows. The fifth row provides a total number of OFDM symbols per slot. For example, the column corresponding to numerology -1 has seven OFDM symbols per slot, whereas the column corresponding to numerology -1B has 14 OFDM symbols per slot. Traditional LTE numerologies include 14 OFDM symbols per slot. However, with new uses for NR being pioneered, other numbers of OFDM symbols per slot are being considered, such as 7 (as in numerology -1) , 12 (as in numerology 1 ECP) , or 10 (as in numerology 2 e ECP) .
It has been observed that in some ATG applications, propagation delay due to reflection off of tall buildings or mountains may be as high as 8.33 μs. Thus, the propagation delay of ATG applications may be significantly more than that expected from NTN applications or terrestrial applications. Some implementations described herein include a cyclic prefix that is equal to or greater than 8.33 μs to accommodate the propagation delay that might be expected in some ATG applications. Another issue in ATG applications might be Doppler effect. For instance, at 700 MHz, a maximum line of sight Doppler effect might be as large as 0.77 kHz. As center frequency increases, the line of sight Doppler effect might increase more than proportionally. For instance, at 3.5 GHz, the maximum line of sight Doppler effect might be around 3.89 kHz, and at 4.8 GHz, the maximum line of sight Doppler effect might be around 5.33 kHz. In some instances, a UE or a base station may have hardware and software capable of compensating for Doppler effect that is as high as about 10%of the SCS. Some UEs or base stations may include better or poorer capability, and this is just an example. Nevertheless, for implementations assuming compensation abilities exist for up to 10%of SCS, then in a numerology using 700 MHz, an SCS of 7.5 kHz or greater would be desirable. Similarly, in a numerology using a center frequency of 3.5 GHz, an SCS of 30 kHz or 60 kHz would be desirable, and in a numerology using 4.8 GHz as a center frequency, an SCS equal to or greater than 60 kHz would be desirable.
However, these concerns may also run into other constraints, such as available bandwidth on a center frequency or attenuation expected to affect a center frequency. Thus, while numerology -1 may have ample SCS and CP at 700 MHz, that center frequency may not provide a desired amount of bandwidth for an ATG UE that is built for 1 GHz or more bandwidth. Similarly, numerologies 3 and 4 may be best reserved for millimeter wave applications, though millimeter wave may experience attenuation that makes it unsuitable for the long distances covered by an ATG base station cell.
One possible solution might be to use numerology 1 ECP, which has an SCS of 30 kHz and a cyclic prefix of 8.33 μs. Numerology 1 ECP may be used with 3.5 GHz, thereby providing SCS of 30 kHz and CP of 8.33 μs. Those parameters may provide acceptable performance in an ATG application, considering propagation delay, Doppler effect, and expected attenuation. Similarly, numerology 2 eECP may be used with either 3.5 GHz or 4.8 GHz as a center frequency to provide SCS of 60 kHz and CP of 8.33 μs. Once again, these parameters may provide acceptable performance in an ATG application. The numerologies including “ECP” refer to an extended CP, which is accomplished by reducing a number of OFDM symbols per slot. Disadvantages associated with ECP numerologies include a reduction in efficiency due to the relative length of the CP versus the total symbol duration as well as mismatch with traditional numerologies having 14 symbols per OFDM slot. However, in some applications, the disadvantages of those numerologies may be outweighed by the advantages. In fact, for any given application, an engineer may pick a numerology for use based on a variety of factors. ATG applications present their own special considerations, propagation delay and Doppler effect being among them, which makes them different from other applications, such as a NTN and car-based terrestrial.
As noted above, traditional LTE numerologies include 14 OFDM symbols per slot. The number of OFDM symbols allow different emitters to coexist more easily. In the case of numerology -1, it has seven OFDM symbols per slot, but it aligns with traditional numerologies including 14 OFDM symbols per slot since 14 is a multiple of seven. However, the other numerologies in the table of Figure 4 may include 12 OFDM symbols per slot or 10 symbols per slot in order to accommodate a larger CP. Since neither 10 nor 12 are a multiple of seven, such numerologies create misalignment when coexisting with other applications using seven or 14 OFDM symbols per slot. Thus, ATG applications adopting a numerology using 10 or 12 (or some other number of OFDM symbols per slot) may cause incrementally more interference with terrestrial UEs.
While Figure 4 describes different numerologies that may be used in ATG applications, other options may exist as well. For instance, as wireless communications progress, other waveforms are being developed and used. The example above in Figure 4 assumes OFDM waveforms. Other waveforms that may be used include orthogonal time frequency space (OTFS) , direct Fourier transform spread OFDM (DFT-s-OFDM) , single carrier waveform, CDMA, GSM. OTFS is a particular case of time frequency spreading, and other time frequency spreading waveforms may be considered for use in various implementations as well.
Looking to OTFS first, it may be implemented in some ATG applications due to various advantageous features. For instance, OTFS may be used with any appropriate subcarrier spacing, such as 30 kHz or 60 kHz. Therefore, OTFS may provide acceptable performance when Doppler effect is expected to be relatively high. Also, OTFS may omit using a CP, which may increase its spectral efficiency compared with OFDM waveforms having a larger CP. Nevertheless, OTFS does have other concerns, such as the use of more complex receivers to account for inter-symbol interference in the time domain. While more complex receivers may be acceptable for use in projects that are less cost-sensitive, more cost-sensitive projects may be less likely to adopt the complex receivers associated with OTFS. Nevertheless, as time goes on, the cost of hardware and software capable of communicating using OTFS may decrease, thereby making OTFS more acceptable to general aviation. In the meantime, OTFS receivers may be more likely to be adopted by commercial and governmental aircraft.
In one use case, OTFS may be desirable for use during some flight scenarios. For instance, OTFS decoding latency may be higher than in OFDM because of the increased complexity of decoding in OTFS. OTFS may be a desirable option to choose when the Doppler effect is high, such as when an aircraft is en route. However, OFDM with its lower latency may be desirable when the Doppler effect is lower, such as during takeoff and landing. Accordingly, some ATG systems may be capable of switching between waveforms as appropriate.
Different waveforms may cause interference. For instance, for a terrestrial UE using OFDM for its downlink, it may experience increased interference from an uplink signal from an ATG UE using OTFS both because of the high power expected to be used by the ATG UE as well as the difference in time domain and frequency domain properties present in the OTFS waveform. For instance, OTFS may include a shorter symbol duration relative to OFDM, and that unmatched symbol alignment may increase interference. In other words, just as numerologies with non-aligning numbers of symbols in a slot may be expected to cause increased interference, an OTFS waveform spreads data over both the time and frequency domains and, thus, has increased non-alignment issues when interfering with an OFDM downlink. So as ATG applications may increase use of other waveforms, such as time frequency spreading and others, terrestrial UEs may expect to see interference from those sources. In addition to the misalignment caused by different numerologies in different waveforms, various ATG applications may experience propagation delays significantly different from those experienced by terrestrial UEs, and that difference in timing alignment may further increase interference experienced by terrestrial UEs.
Figure 5 is an illustration of an example wireless communication network according to one implementation. Figure 5 is offered to illustrate coexistence of an ATG BS 105g with a plurality of terrestrial BSs 105d, 105e. Terrestrial BSs 105d may be substantially the same as the terrestrial BS 105d of Figure 1. Also, the UEs 115a, 115b may be the same as or similar to UEs 115a, 115b of Figure 1. Terrestrial BS 105e may also be the same as or similar to any of the BSs 105 of Figure 1, and UEs 115o, 115p may also be the same as or similar to any of the BSs of Figure 1. And although not shown in Figure 5, ATG BS 105g may have a backhaul connection with either one or both of the terrestrial BSs 105d, 105e.
Figure 5 shows that the terrestrial cells 502, 503 may be encompassed by the large area of ATG cell 501. In some implementations, ATG cell 501 may encompass more or fewer terrestrial cells, and some terrestrial cells may be partially within and partially without cell 501. The two terrestrial cells 502, 503 are shown encompassed by ATG cell 501 for ease of illustration, and it is understood that in some applications an example ATG cell 501 may encompass tens or even hundreds of terrestrial cells within a 200 km or 300 km radius.
An option for multiplexing ATG communications and terrestrial NR is frequency division multiplexing, although that may suffer from low spectral efficiency in some instances. Another more spectral-efficient way to allow a non-orthogonal use of radio frequencies among ATG assets and terrestrial assets is OTFS, which may cause other issues to arise. For instance, spectral efficiency may be low at higher frequencies (e.g., 4.8 GHz) due to larger Doppler effect and propagation delay.
Various implementations herein propose to use NR techniques with different waveforms than OFDM in order to achieve a higher spectral efficiency considering large Doppler effect and delays that might be expected in ATG applications. In doing so, there may be interference, such as illustrated in Figure 5. Nevertheless, despite the potential for interference, the benefits of using different waveforms are evident. As noted above, some different waveforms, such as OTFS, may achieve a higher spectral efficiency considering large Doppler effect and delays that might be expected in ATG applications. Also, as noted above, OTFS may be a desirable option to choose when the Doppler effect is high, such as when an aircraft is en route, and, OFDM with its lower latency may be desirable when the Doppler effect is lower, such as during takeoff and landing. Therefore, there may be benefit in allowing some NR systems to switch between different waveforms as appropriate. While the examples herein are given with respect to an ATG UE, it should be noted that the scope of implementations is not so limited. Rather, a terrestrial UE may be adapted according to the principles herein. For instance, a terrestrial UE may be configured to switch between different waveforms to increase reliability, to decrease power use, to avoid interference from another waveform, and/or the like.
Figure 6 is an illustration of an example method 600 for using multiple waveforms by a UE. Method 600 may be performed by a UE, such as any of the UEs 115 of Figure 1 and 5. For instance, the UE may be a terrestrial UE or an ATG UE. The actions of method 600 are performed as the UE communicates with the BS, which may be any of the BSs 105 of Figure 1 and 5.
At action 601, the UE transmits information regarding its capabilities to a BS. In this example, the UE may be camping on the BS, or the transmitting may take place during an initial access procedure or later when user data is being transmitted. Further in this example the capabilities refer to which waveforms may be supported by the UE, allowing the base station to schedule appropriate waveforms.
In the case of an ATG UE, some commercial aircraft may include robust UEs that may be able to support many waveforms. By contrast, general aviation aircraft and terrestrial UEs may be less robust and may support a fewer number of waveforms. In other words, different kinds of UEs may have different kinds of capabilities and, thus, action 601 allows the UE to report its capabilities to the BS.
For instance, in a use case example, a particular UE may report to the BS that various waveforms are available or preferred. Example waveforms include, but are not limited to, OFDM, OTFS, DFT-s-OFDM, single carrier waveform, CDMA, and GSM. In addition to reporting capabilities regarding supported waveforms, various implementations also include the UE providing information regarding whether it supports dual connectivity carrier aggregation (DC-CA) . Carrier aggregation generally refers to the ability of carriers to be aggregated and transmitted in parallel to/from the same UE to allow for wider bandwidth and higher data rates. A UE capable of carrier aggregation may receive or transmit simultaneously on multiple component carriers (CCs) . Dual connectivity refers to the ability of the UE to have simultaneous connectivity to multiple nodes within a radio access network and, thus, DC-CA may provide the ability for UE to access two different CCs each using a different waveform. This is described in more detail with respect to actions 602-604.
An action 602, the UE receives and processes configuration information from the base station, where the configuration information is based at least in part on the capability of the first UE. For instance, once the BS is aware of the capabilities of the UE, then it may determine combinations of waveforms to be assigned or scheduled to the UE.
In one example, the BS determines to configure the UE so that different BWPs are associated with different waveforms. So, for instance, the BS may determine a configuration that looks like: BWP#0-OFDM, BWP#1-DFT-s-OFDM, BWP#2-Time-Freq-Spreading, BWP#3-OTFS. Of course, that is just one example, and it assumes that the UE supports those different waveforms. In some instances, a UE may support a fewer number of waveforms, such as only OFDM and single carrier or OFDM and DFT-s-OFDM. In such instances, the BS may determine a configuration that uses any combination of BWPs to support multiple waveforms according to the capability of the UE. Furthermore, in some instances, multiple BWPs may be assigned to a same waveform, while other BWPs are assigned to one or more other waveforms. In other words, the scope of implementations does not exclude the possibility of a combination of waveforms using fewer than four individual waveforms.
In another example, the BS determines to configure the UE so that different CCs are assigned to different waveforms. For example, a first CC may be assigned to OFDM, and a 2
nd CC may be assigned to OTFS. Once again, this is just an example, and the scope of implementations is not limited to any specific combination of waveforms to be assigned to different CCs. In fact, any appropriate combination of different waveforms may be used according to the capabilities of the UE. Furthermore, assigning different CCs to different waveforms may assume that at action 601 the UE indicated that it supports DC-CA. Currently, general aviation aircraft may prefer not to support DC-CA with multiple waveforms, whereas commercial aircraft may have more complex receivers and may have more robust support for a variety of DC-CA combinations. However, the scope of implementations is not limited to using DC-CA with commercial aircraft, as any appropriate UE having DC-CA capability may be adapted for use as described herein.
The configuration information of action 602 may be included in any appropriate control signal. For instance, assigning different BWPs to different waveforms may be accomplished using RRC. Additionally, the UE may be scheduled with an updated waveform using DCI to associate a BWP to a waveform or to switch between BWPs. Also, switching between BWPs may be performed semi-persistently according to RRC signaling.
At action 603, the UE communicates with the BS using the first waveform according to the configuration information. In one example, the UE is configured to use different waveforms with different BWPs. Thus, the UE may communicate with the UE using the first BWP and using the first waveform. In another example, the UE is configured to use different waveforms with different CCs. Thus, the UE may communicate with the UE using the first CC and using the first waveform.
At action 604, the UE communicates with the BS using the second waveform according to the configuration information. Looking first at an example in which the UE is configured to use different waveforms with different BWPs, switching between different waveforms may be performed dynamically or semi-persistently. For instance, the BS may use DCI to schedule the UE to switch from a first BWP to a second BWP, thereby switching between waveforms. Thus, some implementations may include DCI having a BWP identifier in it. Switching between different BWPs may also be indicated semi-persistently using RRC. Of course, the scope of implementations is not limited to any particular control signaling, as any appropriate control signaling to switch between BWPs and/or waveforms may be used.
One example of switching between waveforms was discussed briefly above. Specifically, OFDM may provide good performance, especially with respect to latency, during takeoff and landing, whereas OTFS may provide better spectral efficiency and Doppler performance when an aircraft is en route. Some implementations may include the BS causing the UE to switch between OFDM and OTFS as the aircraft transitions between takeoff and being en route or may cause the UE to switch between OTFS and OFDM as the aircraft transitions between being en route and landing. Implementations described herein allow the aircraft to switch between waveforms by switching between BWPs. Note that switching between BWPs may include using configuration information, such as RRC parameters and DCI. In other words, the configuration information discussed above at 601 may be applied at actions 603-604 to affect a switch between BWPs.
Now looking to an example in which the UE is configured with multiple CCs using different waveforms. In this example, the UE may support DC-CA and, thus, may be able to access both CCs at the same time. The BS may then use one CC more heavily during takeoff and landing and the other CC more heavily when the aircraft is en route.
The scope of implementations is not limited to the specific actions described above. Rather, other embodiments may add, omit, rearrange, or modify any of the actions described above.
For instance, in one example, different RRC parameters and/or DCI fields may support multiple waveforms, and each CC or BWP may include different configurations for different waveforms. Various embodiments may use DCI to tell the UE of a schedule of waveforms. In this example, instead of switching between BWPs and component carriers, each BWP or component carrier may be switched between waveforms. Various embodiments may indicate waveforms in semi-persistent scheduling (e.g., RRC) or DCI. When implemented within the method of Figure 6, such ability may allow the UE to switch between waveforms while continuing to use a same BWP or CC according to scheduling.
Additionally, method 600 may further include the base station configuring the UE to perform rate matching with respect to an additional and different waveform. The additional or different waveform may be associated with another UE or another base station, and the base station may configure the UE for rate matching by providing an RRC parameter or other appropriate information. Rate matching is described in more detail with respect to Figure 8.
In some instances, PDCCH may only include OFDM in some instances because PDCCH does not require as high throughput as PDSCH/PUSCH/PUCCH. Also, PDCCH may not include enough symbols to be spread using OTFS in some implementations.
Figure 7 is an illustration of an example method 700 for using multiple waveforms by a UE. Method 700 may be performed by a UE, such as any of the UEs 115 of Figure 1 and 5. For instance, the UE may be a terrestrial UE or an ATG UE. The actions of method 700 are performed as the UE communicates with the BS, which may be any of the BSs 105 of Figure 1 and 5.
In general, it is expected that a BS may have a higher beamforming capability than does a UE. Specifically, the base station may include enhanced transmitting beamforming capability due to having a more robust antenna array. By contrast, the UE, even an ATG UE, may as a default use omnidirectional antennas with weaker beamforming capability. The result is that multipath effects may be asymmetrical as to uplink and downlink, so there may be greater multipath issues for uplink communications than for downlink communications. Method 700 uses separate waveforms for uplink and downlink to address this disparity. In one example, the ATG application uses OFDM on the downlink and uses OTFS on the uplink. While the uplink may be expected to be affected by multipath, the time and spectrum spreading of OTFS may ameliorate the effects of multipath on the uplink communications, and the system may still take advantage of the low latency of OFDM on the downlink. And while this example is given with respect to an ATG application, it is noted that the scope of implementations is not limited to ATG applications. Rather, the principles described herein may be applied to other applications, such as terrestrial applications.
At action 701, the BS receives and processes configuration information specifying uplink communications using OTFS or a single carrier waveform and specifying downlink communication using an OTFS waveform. The configuration information may specify the uplink and downlink communications according to the different waveforms using any appropriate control signal, such as RRC or DCI.
At action 702, the UE communicates with the base station using the OTFS waveform or single carrier waveform in uplink according to the configuration information.
At action 703, the UE communicates with the base station using the OFDM waveform in downlink according to the configuration information. The switch from waveform to waveform between actions 702 and 703 may be scheduled semi-persistently (e.g., by RRC) or dynamically (e.g., by DCI) .
In method 700, the UE may be configured to operate either in frequency division duplexing (FDD) mode or TDD mode with a particular CC. In instances in which TDD is used, the BS may determine an appropriate gap time between the uplink and the downlink to ensure overall time domain alignment. For instance, a time slot in OTFS may be different compared to a time slot in OFDM. So the two different waveforms may not be time domain aligned without the use of a gap time.
FIG. 8 is an illustration of an example method 800 for rate matching by a UE. Method 800 may be performed by a UE, such as any of the UEs 115 of Figure 1 and 5. For instance, the UE may be a terrestrial UE or an ATG UE. The actions of method 800 are performed as the UE communicates with the BS, which may be any of the BSs 105 of Figure 1 and 5. As described herein, rate matching may include a process of sizing and/or modulating data to fit into a particular block of time-frequency elements (such as available resource elements within a time frame, such as a slot, according to embodiments of the present disclosure) . For instance, rate matching may include sizing and/or modulating the contents of various resource elements on an uplink signal or a downlink signal so as to reduce misalignment or interference with respect to signals of another UE or another BS.
It was noted above that the duration of an OTFS waveform is shorter than the duration of an OFDM waveform. Thus, a UE using OTFS may experience interference by an OFDM source that is non-aligned (or vice versa) . Various implementations herein configure a UE to rate match around signals associated with waveforms different from a waveform associated with a currently active BWP of the UE. In one example, the base station transmits RRC parameters to the UE, where those RRC parameters describe the other waveform. In an example in which the base station configures the UE to use different waveforms (either in different BWPs or in different CCs) , then the base station may be programmed so when it performs that configuration it also additionally provides the RRC parameters associated with expected interference from another waveform.
Due to unmatched symbol alignment among different waveforms, some symbols may be only partially affected by the interfering signal, and partially affected symbols may also be rate match around. However, in an instance in which the impact on a partially affected symbol is only within a cyclic prefix of the affected symbol, the UE may be configured to refrain from rate matching around.
At action 801, the UE communicates with the BS using a first waveform. Examples of waveforms are given above, and any appropriate waveform may be used.
At action 802, the UE receives and processes configuration information from the base station specifying a parameter for a second waveform. For instance, the base station may configure the UE by transmitting RRC parameters that are associated with a different waveform. For example, if the UE has an active BWP and is using an OFDM waveform, then the RRC parameters may be associated with an OTFS waveform or other waveform different from OFDM.
In response to the configuration information, the UE then performs rate matching with respect to the second waveform. Of course, if a symbol is only affected within its CP, then the UE may refrain from rate matching at least for that symbol. However, the UE may still perform rate matching with respect to other affected symbols.
Other implementations may include actions performed by the BS. For instance, the BS may receive information regarding UE capabilities and then provide appropriate configuration information, such as described above with respect to Figures 6-8.
Various implementations may provide one or more advantages. For instance, in implementations that jointly support multiple waveforms by the UE, then the UE may take advantage of a first waveform providing more robust operation with respect to Doppler effect in timing alignment when appropriate and then switching to another waveform to take advantage of decreased latency when appropriate. By assigning a particular waveform to either a BWP or a CC, then switching between waveforms may be performed by switching between BWPs or CCs. Similarly, by using separate waveforms for the uplink and downlink, a UE may take advantage of a first waveform more appropriate for beam forming by the BS and another waveform that is more appropriate for an omnidirectional antenna of the UE. Similarly, configuring the UE to perform rate matching may allow the UE to coexist with another UE using a different waveform.
FIG. 9 is a block diagram of an exemplary UE 900 according to some aspects of the present disclosure. The UE 900 may be a UE 115 discussed above in FIGS. 1 and 5. As shown, the UE 900 may include a processor 902, a memory 904, a transceiver 910 including a modem subsystem 912 and a radio frequency (RF) unit 914, and one or more antennas 916. These elements may be in direct or indirect communication with each other, for example via one or more buses.
The processor 902 may include a central processing unit (CPU) , a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 902 may also be implemented as a combination of computing devices, e.g., 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.
The memory 904 may include a cache memory (e.g., a cache memory of the processor 902) , random access memory (RAM) , magnetoresistive RAM (MRAM) , read-only memory (ROM) , programmable read-only memory (PROM) , erasable programmable read only memory (EPROM) , electrically erasable programmable read only memory (EEPROM) , flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. For instance, memory 904 may include a ROM that stores a database, where that database includes information indicating capabilities, such as with respect to waveforms they can be used for PDSCH and waveforms that can be canceled.
In an aspect, the memory 904 includes a non-transitory computer-readable medium. The memory 904 may store, or have recorded thereon, instructions 906. The instructions 906 may include instructions that, when executed by the processor 902, cause the processor 902 to perform the operations described herein with reference to the UEs 115 in connection with aspects of the present disclosure, for example, aspects of FIGS. 1-8. Instructions 906 may also be referred to as program code. The program code may be for causing a wireless communication device to perform these operations, for example by causing one or more processors (such as processor 902) to control or command the wireless communication device to do so. The terms “instructions” and “code” should be interpreted broadly to include any type of computer-readable statement (s) . For example, the terms “instructions” and “code” may refer to one or more programs, routines, sub-routines, functions, procedures, etc. “Instructions” and “code” may include a single computer-readable statement or many computer-readable statements.
As shown, the transceiver 910 may include the modem subsystem 912 and the RF unit 914. The transceiver 910 can be configured to communicate bi-directionally with other devices, such as the BSs 105. The modem subsystem 912 may be configured to modulate and/or encode the data from the memory 904 and/or the beam module 908 according to a modulation and coding scheme (MCS) , e.g., a low-density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit 914 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc. ) modulated/encoded data (e.g., PUCCH control information, PRACH signals, PUSCH data, beam refinement request, beam switch command, reference signals) from the modem subsystem 912 (on outbound transmissions) or of transmissions originating from another source such as a UE 115 or a BS 105. The RF unit 914 may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver 910, the modem subsystem 912 and the RF unit 914 may be separate devices that are coupled together at the UE 115 to enable the UE 115 to communicate with other devices.
The RF unit 914 may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information) , to the antennas 916 for transmission to one or more other devices. The antennas 916 may further receive data messages transmitted from other devices. The antennas 916 may provide the received data messages for processing and/or demodulation at the transceiver 910. The transceiver 910 may provide the demodulated and decoded data (e.g., SSBs, PDCCH, PDSCH, beam switch command, CSI-RS resource configuration, CSI-RS reporting configuration, ) to the processor 902 processing. The antennas 916 may include multiple antennas of similar or different designs in order to sustain multiple transmission links. The RF unit 914 may configure the antennas 916.
In an aspect, the UE 900 can include multiple transceivers 910 implementing different RATs (e.g., NR and LTE) . In an aspect, the UE 900 can include a single transceiver 910 implementing multiple RATs (e.g., NR and LTE) . In an aspect, the transceiver 910 can include various components, where different combinations of components can implement different RATs.
FIG. 10 is a block diagram of an exemplary BS 1000 according to some aspects of the present disclosure. The BS 1000 may be a BS 105 in the network 100 as discussed above in FIGS. 1 and 5. A shown, the BS 1000 may include a processor 1002, a memory 1004, a transceiver 1010 including a modem subsystem 1012 and a RF unit 1014, and one or more antennas 1016. These elements may be in direct or indirect communication with each other, for example via one or more buses.
The processor 1002 may have various features as a specific-type processor. For example, these may include a CPU, a DSP, an ASIC, a controller, a FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 1002 may also be implemented as a combination of computing devices, e.g., 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.
The memory 1004 may include a cache memory (e.g., a cache memory of the processor 1002) , RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, a solid state memory device, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some aspects, the memory 1004 may include a non-transitory computer-readable medium. The memory 1004 may store instructions 1006. The instructions 1006 may include instructions that, when executed by the processor 1002, cause the processor 1002 to cause the other components of the base station 1000 to communicate with the UE 1000, such as by transmitting SSBs, configurations, and the like, and actions described above with respect to FIGS. 1-8. Instructions 1006 may also be referred to as code, which may be interpreted broadly to include any type of computer-readable statement (s) as discussed above with respect to FIG. 9.
As shown, the transceiver 1010 may include the modem subsystem 1012 and the RF unit 1014. The transceiver 1010 can be configured to communicate bi-directionally with other devices, such as the UEs 115 and/or another core network element. The modem subsystem 1012 may be configured to modulate and/or encode data according to a MCS, e.g., a LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit 1014 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc. ) modulated/encoded data (e.g., SSBs, RMSI, MIB, SIB, frame based equipment-FBE configuration, PRACH configuration PDCCH, PDSCH) from the modem subsystem 1012 (on outbound transmissions) or of transmissions originating from another source such as a UE 115, the node 315, and/or BS 1000. The RF unit 1014 may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver 1010, the modem subsystem 1012 and/or the RF unit 1014 may be separate devices that are coupled together at the BS 105 to enable the BS 105 to communicate with other devices.
The RF unit 1014 may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information) , to the antennas 1016 for transmission to one or more other devices. The antennas 1016 may be similar to the antennas of the BS 105 discussed above. This may include, for example, transmission of information to complete attachment to a network and communication with a camped UE 115 according to some aspects of the present disclosure. The antennas 1016 may further receive data messages transmitted from other devices and provide the received data messages for processing and/or demodulation at the transceiver 1010. The transceiver 1010 may provide the demodulated and decoded data (e.g., PUCCH control information, PRACH signals, PUSCH data) to the processor 1002 for processing. The antennas 1016 may include multiple antennas of similar or different designs in order to sustain multiple transmission links.
In an aspect, the BS 1000 can include multiple transceivers 1010 implementing different RATs (e.g., NR and LTE) . In an aspect, the BS 1000 can include a single transceiver 1010 implementing multiple RATs (e.g., NR and LTE) . In an aspect, the transceiver 1010 can include various components, where different combinations of components can implement different RATs.
The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, an 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, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) .
The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items (for example, a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive 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 (i.e., A and B and C) .
As those of some skill in this art will by now appreciate and depending on the particular application at hand, many modifications, substitutions and variations can be made in and to the materials, apparatus, configurations and methods of use of the devices of the present disclosure without departing from the spirit and scope thereof. In light of this, the scope of the present disclosure should not be limited to that of the particular implementations illustrated and described herein, as they are merely by way of some examples thereof, but rather, should be fully commensurate with that of the claims appended hereafter and their functional equivalents.
Implementation examples are described in the following numbered clauses:
1. A method performed by a user equipment (UE) , the method comprising:
processing configuration information specifying communication using a first waveform in a first bandwidth part (BWP) or a first component carrier (CC) and a second waveform in a second BWP or a second CC, wherein the first waveform and the second waveform are different;
communicating with a base station using the first waveform according to the configuration information; and
subsequent to using the first waveform, communicating with the base station using the second waveform according to the configuration information.
2. The method of clause 1, wherein the first waveform comprises orthogonal frequency division multiplexing (OFDM) , and the second waveform comprises orthogonal time frequency and space (OTFS) .
3. The method of clauses 1-2, wherein the configuration information comprises radio resource control (RRC) information.
4. The method of clauses 1-3, wherein a switch from the first waveform to the second waveform is performed according to dynamically using DL control information (DCI) .
5. The method of clauses 1-4, wherein the method is performed by an air to ground (ATG) UE.
6. The method of clauses 1-5, further comprising:
reporting UE capability information to the base station, the UE capability information identifying the first waveform and the second waveform as available to the UE.
7. The method of clauses 1-6, further comprising:
reporting UE capability information to the base station, the UE capability information identifying availability of dual connectivity carrier aggregation (DC-CA) .
8. The method of clauses 1-7, further comprising:
receiving further configuration information to indicate switching between the second waveform and the first waveform while continuing to use the second BWP or the second CC.
9. The method of clause 8, wherein the further configuration information comprises an item selected from a list consisting of: DL control information (DCI) ; and a radio resource control (RRC) signal.
10. The method of clauses 1-9, further comprising:
processing further configuration information regarding an additional waveform; and
performing rate matching with respect to the additional waveform.
11. A user equipment (UE) comprising:
a transceiver; and
a processor controlling the transceiver, the processor configured to:
process configuration information specifying uplink communications using an orthogonal time frequency and space (OTFS) waveform or a single carrier waveform and specifying downlink communication using an orthogonal frequency division multiplexing (OFDM) waveform;
communicate with a base station using the OTFS waveform or the single carrier waveform in uplink according to the configuration information; and
communicate with the base station using the OFDM waveform in downlink according to the configuration information.
12. The UE of clause 11, wherein the configuration information comprises radio resource control (RRC) information.
13. The UE of clauses 11-12, wherein the processor is configured to perform a switch from the OTFS waveform or the single carrier waveform to the OFDM waveform dynamically according to DL control information (DCI) .
14. The UE of clauses 11-13, comprising an air to ground (ATG) applications.
15. The UE of clauses 11-14, wherein the processor is configured to communicate with the base station using the OTFS waveform and communicate with the base station using the OFDM waveform according to time domain duplexing (TDD) , further wherein the configuration information indicates a time gap between downlink and uplink.
16. A user equipment (UE) comprising:
means for communicating with a base station using a first waveform;
means for processing configuration information from the base station specifying a parameter for a second waveform; and
means for rate matching with respect to the second waveform, wherein the first waveform and the second waveform are different.
17. The UE of clause 16, wherein reception of the configuration information is associated with the UE switching between waveforms.
18. The UE of clauses 16-17, wherein the configuration information comprises radio resource control (RRC) information.
19. The UE of clauses 16-18, comprising an air to ground (ATG) application.
20. The UE of clauses 16-19, wherein the means for rate matching further includes means for omitting rate matching with respect to a symbol in the first waveform wherein only a cyclic prefix (CP) of the symbol is affected.
21. The UE of clauses 16-20, wherein the first waveform comprises orthogonal frequency division multiplexing, and wherein the second waveform comprises orthogonal time frequency and space (OTFS) .
22. A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:
code for processing configuration information specifying communication using a first waveform in a first bandwidth part (BWP) or a first component carrier (CC) and a second waveform in a second BWP or a second CC, wherein the first waveform and the second waveform are different;
code for communicating with a base station using the first waveform according to the configuration information; and
code for communicating with the base station using the second waveform according to the configuration information subsequent to using the first waveform.
23. The non-transitory computer-readable medium of clause 22, wherein the first waveform comprises orthogonal frequency division multiplexing (OFDM) , and the second waveform comprises orthogonal time frequency and space (OTFS) .
24. The non-transitory computer-readable medium of clauses 22-23, wherein the configuration information comprises radio resource control (RRC) information.
25. The non-transitory computer-readable medium of clauses 22-24, wherein a switch from the first waveform to the second waveform is performed according to dynamically using DL control information (DCI) .
26. The non-transitory computer-readable medium of clauses 22-25, further comprising:
reporting user equipment (UE) capability information to the base station, the UE capability information identifying the first waveform and the second waveform as available to the UE.
27. The non-transitory computer-readable medium of clauses 22-26, further comprising:
reporting user equipment (UE) capability information to the base station, the UE capability information identifying availability of dual connectivity carrier aggregation (DC-CA) .
28. The non-transitory computer-readable medium of clauses 22-27, further comprising:
receiving further configuration information to indicate switching between the second waveform and the first waveform while continuing to use the second BWP or the second CC.
29. The non-transitory computer-readable medium of clauses 28, wherein the further configuration information comprises an item selected from a list consisting of: DL control information (DCI) ; and a radio resource control (RRC) signal.
30. The non-transitory computer-readable medium of clauses 22-29, further comprising:
processing further configuration information regarding an additional waveform; and
performing rate matching with respect to the additional waveform.
Claims (30)
- A method performed by a user equipment (UE) , the method comprising:processing configuration information specifying communication using a first waveform in a first bandwidth part (BWP) or a first component carrier (CC) and a second waveform in a second BWP or a second CC, wherein the first waveform and the second waveform are different;communicating with a base station using the first waveform according to the configuration information; andsubsequent to using the first waveform, communicating with the base station using the second waveform according to the configuration information.
- The method of claim 1, wherein the first waveform comprises orthogonal frequency division multiplexing (OFDM) , and the second waveform comprises orthogonal time frequency and space (OTFS) .
- The method of claim 1, wherein the configuration information comprises radio resource control (RRC) information.
- The method of claim 1, wherein a switch from the first waveform to the second waveform is performed according to dynamically using DL control information (DCI) .
- The method of claim 1, wherein the method is performed by an air to ground (ATG) UE.
- The method of claim 1, further comprising:reporting UE capability information to the base station, the UE capability information identifying the first waveform and the second waveform as available to the UE.
- The method of claim 1, further comprising:reporting UE capability information to the base station, the UE capability information identifying availability of dual connectivity carrier aggregation (DC-CA) .
- The method of claim 1, further comprising:receiving further configuration information to indicate switching between the second waveform and the first waveform while continuing to use the second BWP or the second CC.
- The method of claim 8, wherein the further configuration information comprises an item selected from a list consisting of:DL control information (DCI) ; anda radio resource control (RRC) signal.
- The method of claim 1, further comprising:processing further configuration information regarding an additional waveform; andperforming rate matching with respect to the additional waveform.
- A user equipment (UE) comprising:a transceiver; anda processor controlling the transceiver, the processor configured to:process configuration information specifying uplink communications using an orthogonal time frequency and space (OTFS) waveform or a single carrier waveform and specifying downlink communication using an orthogonal frequency division multiplexing (OFDM) waveform;communicate with a base station using the OTFS waveform or the single carrier waveform in uplink according to the configuration information; andcommunicate with the base station using the OFDM waveform in downlink according to the configuration information.
- The UE of claim 11, wherein the configuration information comprises radio resource control (RRC) information.
- The UE of claim 11, wherein the processor is configured to perform a switch from the OTFS waveform or the single carrier waveform to the OFDM waveform dynamically according to DL control information (DCI) .
- The UE of claim 11, comprising an air to ground (ATG) applications.
- The UE of claim 11, wherein the processor is configured to communicate with the base station using the OTFS waveform and communicate with the base station using the OFDM waveform according to time domain duplexing (TDD) , further wherein the configuration information indicates a time gap between downlink and uplink.
- A user equipment (UE) comprising:means for communicating with a base station using a first waveform;means for processing configuration information from the base station specifying a parameter for a second waveform; andmeans for rate matching with respect to the second waveform, wherein the first waveform and the second waveform are different.
- The UE of claim 16, wherein reception of the configuration information is associated with the UE switching between waveforms.
- The UE of claim 16, wherein the configuration information comprises radio resource control (RRC) information.
- The UE of claim 16, comprising an air to ground (ATG) application.
- The UE of claim 16, wherein the means for rate matching further includes means for omitting rate matching with respect to a symbol in the first waveform wherein only a cyclic prefix (CP) of the symbol is affected.
- The UE of claim 16, wherein the first waveform comprises orthogonal frequency division multiplexing, and wherein the second waveform comprises orthogonal time frequency and space (OTFS) .
- A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:code for processing configuration information specifying communication using a first waveform in a first bandwidth part (BWP) or a first component carrier (CC) and a second waveform in a second BWP or a second CC, wherein the first waveform and the second waveform are different;code for communicating with a base station using the first waveform according to the configuration information; andcode for communicating with the base station using the second waveform according to the configuration information subsequent to using the first waveform.
- The non-transitory computer-readable medium of claim 22, wherein the first waveform comprises orthogonal frequency division multiplexing (OFDM) , and the second waveform comprises orthogonal time frequency and space (OTFS) .
- The non-transitory computer-readable medium of claim 22, wherein the configuration information comprises radio resource control (RRC) information.
- The non-transitory computer-readable medium of claim 22, wherein a switch from the first waveform to the second waveform is performed according to dynamically using DL control information (DCI) .
- The non-transitory computer-readable medium of claim 22, further comprising:reporting user equipment (UE) capability information to the base station, the UE capability information identifying the first waveform and the second waveform as available to the UE.
- The non-transitory computer-readable medium of claim 22, further comprising:reporting user equipment (UE) capability information to the base station, the UE capability information identifying availability of dual connectivity carrier aggregation (DC-CA) .
- The non-transitory computer-readable medium of claim 22, further comprising:receiving further configuration information to indicate switching between the second waveform and the first waveform while continuing to use the second BWP or the second CC.
- The non-transitory computer-readable medium of claim 28, wherein the further configuration information comprises an item selected from a list consisting of:DL control information (DCI) ; anda radio resource control (RRC) signal.
- The non-transitory computer-readable medium of claim 22, further comprising:processing further configuration information regarding an additional waveform; andperforming rate matching with respect to the additional waveform.
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