CN119856441A

CN119856441A - Method, communication device and infrastructure equipment

Info

Publication number: CN119856441A
Application number: CN202380065098.6A
Authority: CN
Inventors: 塞谬尔·阿桑本·阿通西里; 申·霍恩格·翁; 马丁·沃里克·贝亚勒
Original assignee: Sony Group Corp
Current assignee: Sony Group Corp
Priority date: 2022-09-30
Filing date: 2023-09-27
Publication date: 2025-04-18
Also published as: WO2024068750A1; EP4595318A1

Abstract

A method of operating a communication device is provided. The method includes: transmitting a first uplink signal to a cell of a wireless communication network based on a first waveform type; determining that the communication device is to transmit a second uplink signal based on a second waveform type instead of the first waveform type based on satisfying a predetermined condition, the second waveform type being different from the first waveform type; and transmitting the second uplink signal to the cell of the wireless communication network based on the second waveform type. Here, the predetermined condition may include (or may otherwise indicate) that the communication device moves outside the uplink coverage area of the cell of the wireless communication network.

Description

Method, communication device and infrastructure equipment

Background

Technical Field

The present disclosure relates to a communication apparatus, an infrastructure device, and a method for more efficient operation of a communication apparatus and an infrastructure device in a wireless communication network.

The present application claims paris convention priority of european patent application number EP22199303.3 filed at 9 and 30 of 2022, the contents of which are incorporated herein by reference.

Description of related Art

The description of "background art" provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

Previous generation mobile telecommunications systems, such as those based on 3GPP defined UMTS and Long Term Evolution (LTE) architectures, are capable of supporting a wider range of services of simple voice and messaging services provided by previous generations of mobile telecommunications systems. For example, with the improved radio interface and enhanced data rates provided by LTE systems, users can enjoy high data rate applications, such as mobile video streaming and mobile video conferencing, that were previously available only via fixed line data connections. Thus, the demand for deploying such networks is strong, and the coverage areas of these networks (i.e., the geographic locations where the networks can be accessed) are expected to continue to grow rapidly.

Current and future wireless communication networks are expected to routinely and efficiently support communication with an ever-increasing range of devices associated with a wider range of data flow profiles and types than existing systems are optimized to support. For example, it is expected that future wireless communication networks will be expected to efficiently support communication with devices including reduced complexity devices, machine Type Communication (MTC) devices, high resolution video displays, virtual reality headphones, augmented reality (XR), etc. Some of these different types of devices may be deployed in very large numbers, such as low complexity devices for supporting "internet of things", and may generally be associated with the transmission of relatively small amounts of data with relatively high latency tolerance. Other types of devices, such as those supporting high definition video streams, may be associated with the transmission of relatively large amounts of data with relatively low latency tolerance. Other types of devices, such as for autonomous vehicle communications and for other critical applications, may be characterized in that data should be transmitted over a network with low latency and high reliability. A single device type may also be associated with different traffic profiles/characteristics depending on the application it is running. For example, different considerations may be made for efficiently supporting data exchange with a smart phone when the smart phone is running a video streaming application (high downlink data) than when the smart phone is running an internet browsing application (sporadic uplink and downlink data) or is being used by an emergency responder for voice communication in an emergency scenario (data subject to stringent reliability and latency requirements).

In view of this, it is expected that current wireless communication networks (e.g., those networks that may be referred to as 5G or New Radio (NR) systems/new Radio Access Technology (RAT) systems or indeed future 6G wireless communications) are required, as well as future iterations/versions of existing systems, to efficiently support connections for a wide range of devices associated with different applications and different characteristic data flow profiles and requirements.

One example of a new service is known as an ultra-reliable low latency communication (URLLC) service, which, as its name suggests, requires the transmission of data units or packets with high reliability and low communication delay. Another example of a new service is the enhanced mobile broadband (eMBB) service, featuring high capacity, requiring support up to 20Gb/s. Thus, URLLC and eMBB types of services are challenging examples for both LTE type communication systems and 5G/NR communication systems.

5G NR is evolving and current work plans include 5G-NR-advanced, where some further enhancements are expected, especially to support new use cases/scenarios with higher requirements. The desire to support these new use cases and scenarios presents new challenges to be addressed for efficiently handling communications in a wireless communication system.

Disclosure of Invention

The present disclosure may help solve or mitigate at least some of the problems discussed above.

Embodiments of the present technology may provide a method of operating a communication device. The method includes transmitting a first uplink signal to a cell of the wireless communication network based on a first waveform type, determining that the communication device is to transmit a second uplink signal based on a second waveform type other than the first waveform type based on a predetermined condition being satisfied, the second waveform type being different from the first waveform type, and transmitting the second uplink signal to the cell of the wireless communication network based on the second waveform type. Here, the predetermined condition may include that the communication device moves outside an uplink coverage area of a cell of the wireless communication network.

In addition to methods of operating a communication device, embodiments of the present technology relate to methods of operating an infrastructure equipment, communication devices and infrastructure equipment, circuitry for a communication device and infrastructure equipment, computer programs and computer readable storage media may allow for more efficient use of radio resources by a communication device operating in a wireless communication network.

Corresponding aspects and features of the present disclosure are defined in the appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the technology. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

Drawings

A more complete appreciation of the present disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and wherein:

Fig. 1 schematically illustrates some aspects of an LTE-type wireless telecommunications system that may be configured to operate in accordance with certain embodiments of the present disclosure;

Fig. 2 schematically represents some aspects of a new Radio Access Technology (RAT) wireless telecommunications system that may be configured to operate in accordance with certain embodiments of the present disclosure;

FIG. 3 is a schematic block diagram of an example infrastructure device and communications apparatus that may be configured to operate in accordance with certain embodiments of the present disclosure;

fig. 4A and 4B illustrate how initial access and/or uplink Small Data Transmission (SDT) may be performed by a User Equipment (UE) using a Random Access (RACH) scheme while the UE is in an idle or inactive state;

Figure 5 shows a partially schematic, partial message flow diagram representation of a wireless communication system including a communication apparatus and an infrastructure device in accordance with an embodiment of the present technique, and

Fig. 6 shows a flowchart illustrating a process of communication in a communication system according to an embodiment of the present technology.

Detailed Description

Advanced long term evolution radio access technology (4G)

Fig. 1 provides a schematic diagram illustrating some basic functionality of a mobile telecommunication network/system 6, which generally operates according to LTE principles, but which may also support other radio access technologies and may be adapted to implement embodiments of the present disclosure as described herein. Certain aspects of the various elements of fig. 1 and their respective modes of operation are well known and defined in the relevant standards managed by the 3GPP (RTM) agency, and are also described in many books (e.g., holma h. And Toskala a [1 ]) about this theme. It will be appreciated that aspects of the operation of the telecommunications network discussed herein that are not specifically described (e.g., with respect to particular communication protocols and physical channels for communicating between the different elements) may be implemented in accordance with any known technique (e.g., in accordance with related standards and known suggested modifications and additions to related standards).

The network 6 comprises a plurality of base stations 1 connected to a core network 2. Each base station provides a coverage area 3 (i.e., a cell) within which data may be communicated to and from a communication device 4. Although each base station 1 is shown as a single entity in fig. 1, those skilled in the art will appreciate that some of the functions of the base stations may be performed by different interconnected elements, such as an antenna (or multiple antennas), a remote radio head, an amplifier, etc. One or more base stations may together form a radio access network.

Data is transmitted from the base stations 1 via the radio Downlink (DL) to the communication devices 4 within their respective coverage areas 3. Data is transmitted from the communication device 4 to the base station 1 via the radio Uplink (UL). The core network 2 routes data to and from the communication devices 4 via the respective base stations 1 and provides functions such as authentication, mobility management, charging, etc. Terminal devices may also be referred to as mobile stations, user Equipment (UE), user terminals, mobile radios, communication devices, and the like. The services provided by the core network 2 may include connections to the internet or to external telephony services. The core network 2 may also track the location of the communication device 4 so that it can efficiently contact (i.e., page) the communication device 4 to transmit downlink data towards the communication device 4.

A base station that is an example of a network infrastructure device may also be referred to as a transceiver station, node B, e node B, eNB, g node B, gNB, etc. In this regard, different terms are generally associated with different generations of wireless telecommunication systems for elements providing widely comparable functionality. However, certain embodiments of the present disclosure may be equally implemented in different generations of wireless telecommunication systems, and certain terminology may be used for simplicity, regardless of the underlying network architecture. That is, the use of particular terminology for certain example implementations is not intended to indicate that such implementations are limited to only a certain generation of networks that may be most associated with the particular terminology.

New radio access technology (5G)

Systems incorporating NR technology are expected to support different services (or service types), which may be characterized by different requirements for latency, data rate, and/or reliability. For example, enhanced mobile broadband (eMBB) services are characterized by high capacity, requiring support up to 20Gb/s. The requirement for ultra-reliable low latency communication (URLLC) services is one transfer of 32 byte packets within 1ms from the radio protocol layer 2/3SDU entry point to the radio protocol layer 2/3SDU exit point of the radio interface, where the reliability is 1-10 ^-5 (99.999%) or higher (99.9999%) [2].

Large-scale machine type communication (mMTC) is another example of a service that may be supported by NR-based communication networks. In addition, the system is expected to support further enhancements related to the industrial internet of things (IIoT) in order to support services with new requirements for high availability, high reliability, low latency, and in some cases high accuracy positioning.

An example configuration of a wireless communication network using some of the terms proposed for NR and 5G and used in NR and 5G is shown in fig. 2. In fig. 2, a plurality of Transmission and Reception Points (TRP) 10 are connected to distributed control units (DU) 41, 42 through a connection interface denoted as line 16. Each of the TRPs 10 is arranged to transmit and receive signals via the wireless access interface within the radio frequency bandwidth available to the wireless communication network. Thus, each of the TRPs 10 forms a cell as indicated by circle 12 of the wireless communication network within the range for performing radio communication via the wireless access interface. As such, wireless communication devices 14 within radio communication range provided by cell 12 may transmit signals to and receive signals from TRP 10 via the wireless access interface. Each of the distributed units 41, 42 is connected to a Central Unit (CU) 40 (which may be referred to as a control node) via an interface 46. The central unit 40 is then connected to the core network 20, which may contain all other functions necessary for transmitting data for transmission to and from the wireless communication device, and the core network 20 may be connected to the other networks 30.

The elements of the radio access network shown in fig. 2 may operate in a similar manner as the corresponding elements of the LTE network as described with respect to the example of fig. 1. It will be appreciated that the operational aspects of the telecommunications network presented in fig. 2, as well as operational aspects of other networks not specifically described discussed herein (e.g., with respect to particular communication protocols and physical channels for communicating between different elements) discussed in accordance with embodiments of the present disclosure, may be implemented in accordance with any known technique (e.g., in accordance with currently used methods for implementing such operational aspects of a wireless telecommunications system, e.g., in accordance with relevant standards).

The TRP 10 of fig. 2 may have, in part, a function corresponding to a base station or enode B of an LTE network. Similarly, the communication device 14 may have functionality corresponding to UE devices 4 known for operation with LTE networks. Thus, it will be appreciated that operational aspects of the new RAT network (e.g., with respect to specific communication protocols and physical channels for communication between different elements) may differ from those known from LTE or other known mobile telecommunications standards. However, it will also be appreciated that each of the core network components, base stations and communication devices of the new RAT network will be similar in function to the core network components, base stations and communication devices, respectively, of the LTE wireless communication network.

With respect to the broad top-level functionality, the core network 20 connected to the new RAT telecommunications system presented in fig. 2 may be broadly considered to correspond to the core network 2 presented in fig. 1, and the respective central unit 40 and its associated distributed units/TRP 10 may be broadly considered to provide functionality corresponding to the base station 1 of fig. 1. The term network infrastructure equipment/access node may be used for more conventional base station type elements including these elements and wireless telecommunication systems. Depending on the impending application, the responsibility of scheduling the scheduled transmission on the radio interface between the respective distributed unit and the communication device may consist in the control node/central unit and/or the distributed unit/TRP. The communication device 14 is shown in fig. 2 as being located within the coverage area of the first communication cell 12. The communication device 14 may thus exchange signaling with the first central unit 40 in the first communication cell 12 via one of the distributed units/TRPs 10 associated with the first communication cell 12.

It will also be appreciated that fig. 2 presents only one example of the proposed architecture for a new RAT-based telecommunication system, wherein the method according to the principles described herein may be employed and that the functionality disclosed herein may also be applied in respect of a wireless telecommunication system having a different architecture.

Thus, certain embodiments of the present disclosure as discussed herein may be implemented in a wireless telecommunication system/network according to a variety of different architectures, such as the example architectures shown in fig. 1 and 2. Thus, it will be appreciated that the particular wireless telecommunications architecture in any given implementation is not particularly important to the principles described herein. In this regard, certain embodiments of the present disclosure may generally be described in the context of communication between a network infrastructure device/access node and a communication apparatus, where the particular nature of the network infrastructure device/access node and communication apparatus will depend on the network infrastructure for the impending implementation. For example, in some scenarios, the network infrastructure device/access node may comprise a base station (such as LTE type base station 1 as shown in fig. 1) adapted to provide functionality in accordance with the principles described herein, while in other examples, the network infrastructure device may comprise a control unit/control node 40 and/or TRP 10 of the type shown in fig. 2 adapted to provide functionality in accordance with the principles described herein.

Fig. 3 provides a more detailed schematic diagram of some of the components of the network shown in fig. 2. In fig. 3, as a simplified presentation, the TRP 10 shown in fig. 2 includes a wireless transmitter 30, a wireless receiver 32, and a controller or control processor 34 operable to control the transmitter 30 and the wireless receiver 32 to transmit and receive radio signals to one or more UEs 14 within the cell 12 formed by the TRP 10. As shown in fig. 3, the exemplary UE 14 is shown to include a corresponding transmitter 49, receiver 48, and controller 44 configured to control the transmitter 49 and receiver 48 to transmit signals representing uplink data to the wireless communication network via the wireless access interface formed by the TRP 10 and to receive downlink data as signals transmitted by the transmitter 30 and received by the receiver 48 in accordance with conventional operation.

The transmitters 30, 49 and receivers 32, 48 (and other transmitters, receivers and transceivers described with respect to examples and embodiments of the present disclosure) may include radio frequency filters and amplifiers and signal processing components and devices to transmit and receive radio signals according to, for example, the 5G/NR standard. The controllers 34, 44 (and other controllers described with respect to examples and embodiments of the present disclosure) may be, for example, microprocessors, CPUs, or special purpose chipsets configured to execute instructions stored on computer readable media (such as non-volatile memory), or the like. The process steps described herein may be performed by, for example, a microprocessor operating in accordance with instructions stored on a computer readable medium in conjunction with random access memory. For ease of presentation, the transmitter, receiver and controller are schematically shown as separate elements in fig. 3. However, it will be appreciated that the functionality of these elements may be provided in a variety of different ways, for example using one or more suitably programmed programmable computers, or one or more suitably configured application specific integrated circuits/circuitry/chips/chipsets. It will be appreciated that the infrastructure equipment/TRP/base station as well as the UE/communications device will typically include various other elements associated with its operational functions.

As shown in fig. 3, TRP 10 also includes a network interface 50 connected to DU 42 via physical interface 16. Thus, the network interface 50 provides a communication link for data and signaling traffic from the TRP 10 to the core network 20 via the DU 42 and CU 40.

The interface 46 between the DU 42 and the CU 40 is referred to as the F1 interface, which may be a physical interface or a logical interface. The F1 interface 46 between CUs and DUs may operate in accordance with specifications 3gpp TS 38.470 and 3gpp TS 38.473 and may be formed from fiber optics or other wired or wireless high bandwidth connections. In one example, the connection 16 from the TRP 10 to the DU 42 is via an optical fiber. The connection between TRP 10 and core network 20 may be generally referred to as a backhaul, which includes interface 16 from network interface 50 of TRP 10 to DU 42 and F1 interface 46 from DU 42 to CU 40.

RACH procedure in LTE and NR

In wireless telecommunication networks, such as UTE and NR type networks, there are different Radio Resource Control (RRC) modes for the terminal devices. For example, it is common to support an RRC IDLE mode (rrc_idle) and an rrc_connected mode (rrc_connected). A terminal device in idle mode may transition to connected mode, for example, because it needs to transmit uplink data by engaging in a random access procedure or respond to a paging request. The random access procedure involves the terminal device transmitting a preamble on a Physical Random Access Channel (PRACH), and thus the procedure is generally referred to as RACH or PRACH procedure/process, where such RACH procedure may include four steps or two steps, as described in more detail below.

As will be appreciated by those skilled in the art, in addition to the UE performing a RACH procedure to perform initial access by, for example, transitioning from rrc_idle to rrc_connected, the UE may perform a RACH-based scheme (e.g., 2-step RACH or 4-step RACH) while in an rrc_inactive state for the same reasons as performing Small Data Transfer (SDT) without having to first transition to an rrc_connected state with the network.

In addition to the terminal device deciding itself to initiate a random access procedure to connect to the network, the network (e.g., a base station) may instruct the terminal device in connected mode to initiate a random access procedure (by transmitting an instruction to do so to the terminal device). Such an instruction is sometimes referred to as a Physical Downlink Control Channel (PDCCH) command for RACH.

There are various scenarios in which a network triggered RACH procedure (PDCCH order) may occur. For example:

The terminal device may receive a PDCCH order for transmission on the PRACH (as part of the handover procedure);

A terminal device that is rrc_connected with the base station but has not exchanged data with the base station for a relatively long time may receive the PDCCH order to cause the terminal device to transmit the RACH preamble so that it can resynchronize with the network and allow the base station to correct the timing of the terminal device;

The terminal device may receive the PDCCH order so that it may establish a different RRC configuration in a subsequent RACH procedure, which may for example apply to narrowband IoT terminal devices that are prevented from RRC reconfiguration in connected mode, whereby transmitting the terminal device to idle mode via the PDCCH order allows the terminal device to be configured in a subsequent PRACH procedure, e.g., to configure the terminal device for a different coverage enhancement level (e.g., more or less repetition).

For convenience, the term PDCCH order is used herein to refer to signaling transmitted by a base station for instructing a terminal device to initiate a PRACH procedure regardless of the cause. However, it should be understood that such instructions may be transmitted on other channels/in higher layers in some cases. For example, for an intra-system handover procedure, the PDCCH order referred to herein may be an RRC connection reconfiguration instruction transmitted on the downlink shared channel/PDSCH.

When the PDCCH order is transmitted to the terminal device, the terminal device is allocated a PRACH preamble signature sequence for a subsequent PRACH procedure. This is different from a PRACH procedure triggered by a terminal device, in which the terminal device selects a preamble from a predefined set, and thus may proceed by coincident selection of the same preamble as another terminal device that is concurrently performing the PRACH procedure, thereby causing potential contention. Therefore, for the PRACH procedure initiated by the PDCCH order, there is no contention with other terminal apparatuses simultaneously assuming the PRACH procedure, because the PRACH preamble of the terminal apparatus of the PDCCH order is scheduled by the network/base station.

Fig. 4A shows an example of a 4-step RACH based scheme, and also shows how Mobile Originated (MO) SDT may be initiated by such a scheme. When the UE wants or is instructed to perform an initial access, or when the UE has a UL SDT ready for transmission, it may initiate a 4-step RACH procedure as shown in fig. 4A, comprising the steps of:

A UE in RRC IDLE or rrc_inactive starts message 1 (Msg 1) transmission 50 of a Physical Random Access (PRACH) preamble associated with a specific preamble ID and may be selected by the UE from a preamble set assigned for SDT in the current cell. When the gNB receives the preamble, it identifies the UE and/or message 1 (Msg 1) as SDT initiated and responds with message 2 (Msg 2);

gNB transmission 51 (Msg 2), msg2 containing a Random Access Response (RAR) message in response to a RACH preamble transmitted as part of an initial access procedure, wherein RAR comprises a RACH preamble ID (RAPID), a UL timing alignment command, a UL PUSCH schedule for message 3 (Msg 3), and a temporary cell radio network temporary identifier (C-RNTI);

UE transmission 52 (Msg 3), msg3 containing temporary C-RNTI received in Msg2 for identifying UE, radio Resource Control (RRC) signaling (i.e. RRCConnectRequest for initial access or RRCResumeRequest for initiating SDT), and SDT data (if there is any remaining space within scheduled PUSCH);

Then, the gNB provides 53 a contention resolution after identifying and acknowledging the UE transmitting the preamble in the first step 50 via its temporary C-RNTI received in Msg 2. In this step 53, if the UE transmits any small data, DL and UL feedback or acknowledgements are transmitted;

Transmitting hybrid automatic repeat request acknowledgement on cell-specific Physical Uplink Control Channel (PUCCH) resources configured within system information for UL feedback received by a gNB from a UE in response to transmitting a DL PDSCH to the UE

(HARQ-ACK) (although it should be noted that from the third step 52 the UE has been UL synchronized), and

DL feedback received for the UE in response to transmitting UL (Msg 3) in the third step 52, message 4 (Msg 4) is received at the UE in the fourth step 53

Is considered to be a positive acknowledgement, and

After the fourth step 53, if the UE is performing a RACH procedure for initial access purposes, the connection is now established and the UE is now transitioned to the rrc_connected state. Otherwise, if the UE is performing RACH procedure for SDT purposes, the UE is already identified by the network at this time and is also UL synchronized. Thus, if the UE is performing a small data transmission while in the rrc_inactive state, subsequent UL and DL SDTs with dynamic scheduling may occur 54 when needed while the UE remains in the INACTIVE state. Likewise, if the UE is at this time rrc_connected, it may transmit and receive data to and from the network through dynamic scheduling or using a configured grant. Later, once SDT is complete and neither the gNB nor the UE has any additional data to transmit, the gNB may choose to keep the UE in rrc_inactive state by sending RRCRELEASE with a suspend indication 55.

Fig. 4B shows an example of a 2-step RACH based scheme, and also shows how MO SDT may be initiated by such a scheme. When the UE wants to either be instructed to perform an initial access or to have a UL SDT ready for transmission, it may initiate a 2-step RACH procedure as shown in fig. 4B, comprising the steps of:

The UE in rrc_idle or rrc_inactive starts msgA transmission 56 of the PRACH preamble associated with a particular preamble ID and may be selected by the UE from the preamble set assigned for SDT in the current cell and msgA also includes the associated PUSCH in the current cell (i.e. for SDT). If there is any remaining space within the PUSCH, the PUSCH contains RRC signaling (i.e., RRCConnectRequest for initial access or RRCResumeRequest for initiating SDT) and SDT

Data;

Similar to the common 4-step RACH procedure, when the gNB receives 56msgA, it identifies that the UE has initiated the RACH procedure and/or identifies it as SDT initiated and uses msgB

In response 57, msgb contains RACH in response to transmission as part of the initial access procedure

Random Access Response (RAR) message of preamble, wherein RAR includes RAPID, UL

Timing alignment command, C-RNTI and method wherein the transmission 56 is identified and acknowledged in a first step

MsgA UE contention resolution. In this step 57 DL and UL feedback or acknowledgements are transmitted;

For UL feedback received by the gNB from the UE in response to the DL PDSCH transmitted by the gNB to the UE, transmitting by the UE HARQ-ACK on cell-specific PUCCH resources configured within the system information, and

For DL feedback received by the UE from the gNB in response to the UE transmission 56msgA, the receipt 57 of MsgB at the UE is considered a positive acknowledgement;

And

After the second step 57, if the UE is performing RACH for initial access purposes

Procedure, then a connection is established at this time and the UE transitions to rrc_connected at this time

Status of the device. Otherwise, if the UE is performing RACH procedure for SDT purposes, the UE is already identified by the network at this time and is also UL synchronized. Thus, if the UE is performing a small data transmission while in rrc_inactive state, subsequent UL and DL SDTs with dynamic scheduling may occur 58 when needed while the UE remains in INACTIVE state. Likewise, if the UE is now in rrc_connected, it may transmit and receive data to and from the network, typically through dynamic scheduling or using configured grants. Later, once SDT is complete and neither the gNB nor the UE has any additional data to transmit, the gNB may choose to keep the UE in rrc_inactive state by sending RRCRELEASE with a suspend indication 59.

Authorization of configuration

As is well understood by those skilled in the art, the UE uses a Physical Uplink Shared Channel (PUSCH) for uplink data transmission. PUSCH resources for transmission of PUSCH may be scheduled by the gNB using Dynamic Grants (DG) or Configured Grants (CG).

In dynamic grant PUSCH (DG-PUSCH), a UE typically sends a Scheduling Request (SR) to the gNB when uplink data arrives at its buffer. In response to receiving the SR, the gNB will then send an uplink grant to the UE using Downlink Control Information (DCI), e.g., using DCI format 0_0, 0_1, or 0_2 carried via a Physical Downlink Control Channel (PDCCH), where the uplink grant schedules resources for PUSCH. The UE then uses the scheduled PUSCH (i.e., DG-PUSCH) to transmit its uplink data.

It is observed that the use of DG-PUSCH introduces a delay, as the UE needs to initiate SR and has to wait for uplink grants before it is scheduled PUSCH resources. For regular and periodic traffic, DG-PUSCH will cause multiple SRs and uplink grants to be sent, which is not an efficient use of resources. Thus, the disadvantage of DG-PUSCH is recognized, and configured grant PUSCH (CG-PUSCH) is introduced in NR. In CG-PUSCH, the UE uses Radio Resource Control (RRC) configuration for the pre-configuration of periodic PUSCH resources so that the UE can transmit its uplink data in any of these periodically occurring CG-PUSCH resources without requesting it with an SR. There are two types of CG-PUSCH:

type 1CG-PUSCH Once CG-PUSCH resources are configured by RRC, UE can use it without activation, and

Type 2CG-PUSCH resources are first configured by RRC. The UE can only use CG-PUSCH resources if it receives an active DCI, which is a UL grant with a configured scheduling-radio network temporary identifier (CS-RNTI).

Once CG-PUSCH is activated, a UE may use it until it is deactivated by another DCI. The type 2CG-PUSCH provides better control for the gNB scheduler,

And thus more efficiently utilize resources.

CP-OFDM and DFT-S-OFDM

The Coupling Loss (CL) between the UE and the gNB depends largely on the distance between the UE and the gNB, and on any obstacle, such as a building, traffic, foliage, etc., that happens to be in the line of sight between the UE and the gNB. To a lesser extent, CL is also affected by propagation conditions such as fading due to precipitation and doppler spread due to UE mobility. On DL, coverage can be improved by transmitting more power from the gNB. In the UL, the situation may be more critical, given that the power that a given class of UE can transmit is limited by regulations, even though the UE battery may maintain higher power. Therefore, there is a limit to enhance UL coverage by increasing transmit power.

Given CL, it is therefore desirable to be able to improve cell coverage, especially for UEs located at the cell edge. The 3GPP has completed the base release of 5G in 3GPP release 15, known as New Radio (NR), and has added further enhancements in 3GPP releases 16 and 17. In these versions, the transmission in the downlink is based on a cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) waveform, while the uplink may use a CP-OFDM or discrete fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) waveform.

The benefit of supporting DFT-S-OFDM in the uplink is that coverage is increased due to its lower peak-to-average power ratio (PAPR) than CP-OFDM, especially when the UE is at the cell edge. The lower PAPR allows the UE to transmit at a higher average power, which improves UL coverage. DFT-S-OFDM is a form of transform precoding. The DFT-S-OFDM waveform may be used in a single carrier-frequency division multiple access (SC-FDMA) multiple access scheme. Alternatively, the UE may transmit at the same radiated power level in a more efficient manner because the power amplifier in the UE may operate with less backoff. However, DFT-S-OFDM implemented in 3GPP release 15 to release 17 supports only single stream/layer transmission in order to reduce implementation complexity.

All release 17NR capable UEs must support both CP-OFDM and DFT-S-OFDM as UL transmission waveforms. In normal use, the UE receives higher layer "broadcast" signaling (in, for example, system information block 1 (SIB 1)) to enable or disable DFT-S-OFDM for Msg3 transmission during the random access procedure, in terms of informing the UE which waveform to use in the uplink. Alternatively, the UE may receive dedicated semi-static (e.g., radio resource control, RRC) signaling as part of PUSCH (physical uplink shared channel) configuration for UL transmissions. Configuration details for supporting both CP-OFDM and DFT-S-OFDM in the uplink are captured, for example, in section [3] 6.1.3.

As described above, DFT-S-OFDM has a lower PAPR than a multi-carrier CP-OFDM waveform, similar to a single carrier waveform. Thus, a transmitter using DFT-S-OFDM may operate its output power amplifier at its nonlinear characteristic region without fear of excessive waveform clipping, thereby producing lower adjacent channel leakage ratio (acr) and reduced interference at the victim receiver in the adjacent channel. Furthermore, because of its lower ACER (i.e., the ratio of power within an allocated frequency channel to power in an adjacent channel), a UE may operate at a lower Maximum Power Reduction (MPR) factor than a UE transmitting using CP-OFDM. This means that a UE that is allowed to transmit using DFT-S-OFDM in the UL transmits more power (in some cases, up to 1.5dB more power) than a UE that is using CP-OFDM. Thus, the use of DFT-S-OFDM allows a given UE to very efficiently achieve maximum output power for its class while conserving battery power. Furthermore, since DFT-S-OFDM does not support multiple-input multiple-output (MIMO) transmission, there is no cross-space interference, which means that DFT-S-OFDM can provide significantly more coverage than CP-OFDM for the same UE transmission power. On the other hand, this lack of support for MIMO mitigates the use of DFT-S-OFDM for reasons of inefficient use of communication resources. This means that for a typical network, most of the UEs will be configured to use CP-OFDM when in good coverage.

This shows that it would be advantageous for a UE with CP-OFDM configured as its UL waveform to be configured to switch to DFT-S-OFDM (when it needs to increase its coverage because, for example, it is about to come out of good coverage), or for all UL transmissions (such as PUSCH), or only those that are out of coverage.

Configuration of the UL waveform for Msg3 of the 4-step RACH procedure in release 17 is accomplished via the Msg3-transformPrecoding field of the SIB1RACH-ConfigCommon Information Element (IE). Since this is configured in SIB, it is cell specific and the same for all UEs, whether in coverage or out of coverage. Thus, using such SIBs to indicate that a UE in poor coverage or an out-of-coverage UE switches to DFT-S-OFDM is technically not feasible because a UE that is in good coverage and is unlikely to deviate from good coverage will also receive such SIBs. Then, performing such signaling to indicate that a UE in poor coverage or an out-of-coverage UE switching from CP-OFDM to DFT-S-OFDM via SIB would require a specification of e.g. a new, different type of SIB, which would therefore have a quite significant specification impact.

Semi-static configuration of UL waveforms for dynamic grant is implemented in release 17 via transformPrecoding field of RRC PUSCH-Config IE. Similarly, for authorization of the configuration, it is implemented via transformPrecoding field of RRC ConfiguredGrantConfig IE. Semi-static configuration via RRC means that the UE may be configured to use DFT-S-OFDM indefinitely until changed by a new RRC configuration. The network may do so when it determines that the UE is in a limited coverage situation or out of coverage (or about to come out of coverage). However, since RRC configuration may be slow, the UE may have come out of coverage without the opportunity for ACK and application of RRC commands.

Therefore, there is a need to find a more efficient way to instruct a UE to switch waveforms to DFT-S-OFDM, especially when the UE is in poor coverage, out of coverage, or about to be out of coverage. Accordingly, embodiments of the present technology seek to provide solutions for solving such problems.

NR waveform switching for coverage extension

Fig. 5 shows a partially schematic, partial message flow diagram representation of a wireless communication system including a communication apparatus (e.g., UE) 101 and an infrastructure device (e.g., gNB) 102 in accordance with at least some embodiments of the present technology. The communication apparatus 101 is configured to transmit signals to and/or receive signals from a wireless communication network, e.g., to and from an infrastructure device 102. In particular, the communication apparatus 101 may be configured to transmit data to and/or receive data from a wireless communication network (e.g., transmit data to and/or receive data from the infrastructure equipment 102) via a wireless radio interface provided by the wireless communication network (e.g., a Uu interface between the communication apparatus 101 and a Radio Access Network (RAN) including the infrastructure equipment 102). The communication means 101 and the infrastructure equipment 102 each comprise a transceiver (or transceiver circuitry) 101.1, 102.1 and a controller (or controller circuitry) 101.2, 102.2. Each of the controllers 101.2, 102.2 may be, for example, a microprocessor, a CPU, or a dedicated chipset, etc.

As shown in the example of fig. 5, the transceiver circuitry 101.1 and the controller circuitry 101.2 of the communication apparatus 101 are configured in combination to transmit 104 a first uplink signal to a cell of the wireless communication network (e.g., formed by the infrastructure equipment 102) based on a first waveform type (e.g., CP-OFDM) to determine 106 (e.g., based on receiving 110 an indication from the cell of the wireless communication network (e.g., from the infrastructure equipment 102)), to transmit a second uplink signal to the communication apparatus 101 based on a second waveform type (e.g., DFT-S-OFDM) other than the first waveform type based on meeting a predetermined condition, the second waveform type being different from the first waveform type, and to transmit 108 the second uplink signal to the cell of the wireless communication network (e.g., to the infrastructure equipment 102) based on the second waveform type. Here, the predetermined condition may include (or may indicate) that the communication apparatus 101 moves outside an uplink coverage area of a cell of the wireless communication network, or the predetermined condition may include that the UE is handed over (or is about to be handed over) to a non-terrestrial network (NTN) or the like where it would be advantageous to use a waveform such as DFT-S-OFDM.

For UEs that happen to be in an RRC Idle (Idle) mode outside of normal coverage, such UEs may still be possible to reach the network with RACH Msg1 (i.e., of a 4-step RACH procedure) because of the PRACH power ramp that may be engaged during RACH processing. In other words, the first uplink signal may be a first message (e.g., msg 1) of a (4-step) random access RACH procedure initiated by the communication device with a cell of the wireless communication network. Here, the communication device may be configured to determine that the first uplink signal has not been successfully received by the cell of the wireless communication network when it has not received the RAR, and to retransmit the first uplink signal one or more times until it is determined that it has been successfully received by the cell of the wireless communication network. Here, the transmission power of each retransmission of the first uplink signal increases relative to the previous transmission of the first uplink signal.

The gNB may be able to use various means to determine whether the UE is out of normal coverage. For example, based on the last known location of the UE (which may be used to page the UE), or based on the number of PRACH retransmissions performed by the UE, or based on a particular preamble used for successful retransmissions by the UE (where such a preamble may indicate or be associated with a power ramp level-e.g., the UE may use a different sequence to send its last power ramp preamble-the gNB will detect that the UE used a high power ramp on the preamble based on the preamble ID), or based on the subset of preambles that the gNB will use for UEs that are in poor coverage or out of coverage and another subset of UEs that are in normal coverage that remain on it (i.e., preamble splitting), the gNB may be able to detect whether the UE is out of normal coverage. Another way that the gNB may be able to determine whether the UE is outside of normal coverage may be on RACH occasions for the UE to transmit the first signal (i.e., RACH preamble) -e.g., some RACH occasions may be for UEs within normal coverage and other ROs may be for UEs that require coverage extension. In coverage extension, the UE will repeat the preamble. If there are known starting points (ROs) for these repetitions and the gNB detects the preamble only in late ROs, the gNB can know that the UE is in poor coverage.

If the UE has to ramp the power PRACH above a certain level, it should be determined that it should use DFT-S-OFDM for Msg3 or msgA PUSCH, according to some embodiments of the present technique. In other words, the communication device may be configured to determine that the first uplink signal has not been successfully received by a cell of the wireless communication network to retransmit the first uplink signal one or more times, wherein a transmission power of each retransmission of the first uplink signal is increased relative to a previous transmission of the first uplink signal, and based on the transmission power of one of the retransmissions of the first uplink signal being above a specified threshold power, determine that the communication device is to transmit the second uplink signal based on the second waveform type instead of the first waveform type based on the predetermined condition being met.

The UE may also determine whether to use DFT-S-OFDM or CP-OFDM for Msg3 or msgA based on whether the transmission power of the PRACH is above a threshold. That is, the UE may make a determination regarding whether or not the UE needs to perform forming the power ramp. The power threshold may be RRC configured (e.g., in SIB or UE-specific signaling) or predefined in the specification.

In both arrangements of embodiments of the present technology, the UE may autonomously decide which waveform to use based on the amount of power ramp and/or whether the preamble transmission power is above a threshold. Since the gNB does not know which waveform the UE has selected, it may have to blindly decode Msg 3 or msgA PUSCH, attempting to decode it by assuming that the UE has transmitted both DFT-S-OFDM and CP-OFDM. The gNB may estimate whether the UE is at the cell edge or out of coverage and, if so, it may first attempt to decode it using DFT-S-OFDM, and if failed, it uses CP-OFDM and knows that the UE is in coverage for the gNB and vice versa. In other words, the infrastructure equipment may be configured to determine that the first uplink signal is a first message of a random access RACH procedure (e.g., MSGA PRACH of a 2-step RACH procedure or Msg1 of a 4-step RACH procedure) initiated by the communication device with a cell of the wireless communication network, and to receive the second signal by blindly decoding the second signal according to each of the first waveform type and the second waveform type.

As will be appreciated by those skilled in the art, a multi-PRACH transmission is a method for a UE in the cell edge or out of coverage to reach the gNB by transmitting multiple PRACH to the gNB using the same preamble. The gNB will combine these multiple PRACH transmissions to improve its SNR. Thus, in another implementation of embodiments of the present disclosure, the gNB may determine that the UE is out of coverage by determining a number of PRACH transmissions by the UE for Msg1, e.g., if the number of PRACH transmissions for Msg1 is above a threshold, the UE will use a DFT-S-OFDM waveform, otherwise it uses CP-OFDM. The threshold may be configured in a SIB or defined in a specification.

There are implementation specific methods that the network provider can use to determine if the UE is out of coverage. For example, in the prior art in eMTC, the eNB may estimate the location of the UE based on the last known location when the UE was connected, and if the UE is cell edge, the eNB may adjust its repetition of paging messages for it assuming the UE is at the cell edge. Of course, similar and other mechanisms may be used to determine the location of idle mode UEs, as will be appreciated by those skilled in the art.

Alternatively or additionally, if the gNB can determine whether the UE is in coverage, at the cell edge, or out of coverage, e.g., using a vendor specific implementation or standardized method (such as preamble/RACH occasion segmentation) or based on the number of PRACH transmissions, the gNB can include a new bit in the Random Access Response (RAR) to inform the UE that it should use DFT-S-OFDM (4-step RACH) for the Msg3 (e.g., the reserved-i.e., "R" bit in RAR will be known to those skilled in the art) -where the Msg3 may be the second uplink signal transmitted by the UE. In other words, in accordance with such an arrangement of embodiments of the present technology, the indication may be received by the communication device from a cell of the wireless communication network within a random access response, RAR, message that is responsive to the first message of the RACH procedure, wherein the indication may be carried by reserved bits of the RAR message. The infrastructure equipment may be configured to transmit the indication to the communication device based on determining that the UE is at a cell edge or out of coverage.

In at least some such arrangements of embodiments of the present technology, for a 2-step RACH, it has been determined that the gNB, with the UE at the cell edge or out of coverage, engages a DFT-S-OFDM receiver for msgA PUSCH.

In addition to the UE determining that a second uplink signal is to be transmitted based on a second waveform type (e.g., DFT-S-OFDM) instead of the first waveform type based on an indication in the RAR or its PRACH ramp power being higher than a threshold power based on meeting a predetermined condition (e.g., UE to out-of-coverage or out-of-good-coverage), a UE in some arrangements according to embodiments of the present technology may determine that it should switch waveforms based on other indications received from the network. In other words, the communication device may be configured to receive an indication from a cell of the wireless communication network that the communication device is to transmit a second uplink signal based on the second waveform type, and to determine that based on the received indication, the communication device is to transmit the second uplink signal based on the second waveform type instead of the first waveform type based on the predetermined condition being met.

For example, for UEs that happen to be in RRC connected or RRC inactive mode outside (good) UL coverage, the SIB 1transformPrecoding field may be covered via new RRC or MAC CE signaling in some arrangements. In other words, the indication may be received by the communication device from a cell of the wireless communication network in semi-static signaling, where the semi-static signaling may be radio resource control, RRC, signaling, or the indication may be carried by the medium access control, MAC, control element.

In some such arrangements of embodiments of the present technology, the re-write RRC or MAC CE signaling may tell the UE to use DFT-S-OFDM for Msg3 (4-step RACH) or msgA PUSCH (2-step RACH) transmission. In other words, the semi-static signaling may include instructions for the communication device to initiate (4 steps or 2 steps) a random access RACH procedure with a cell of the wireless communication network, and wherein the second uplink signal is a message (e.g., msg3 or msgA) of the RACH procedure.

Other arrangements of embodiments of the present disclosure exist for RACH processing when the UE is in RRC connected mode. For example, the gNB may also include waveforms in the PDCCH order for the RACH by the UE. In other words, the indication may be received by the communication device from a cell of the wireless communication network in a control signal that instructs the communication device to initiate a random access RACH procedure with the cell of the wireless communication network, and wherein the second uplink signal is a message of the RACH procedure.

In other arrangements of embodiments of the present technology, the indication may be received by the communication apparatus in DCI from the infrastructure equipment. For example, for PUSCH, there is a dynamic grant configured for UL data transmission and a grant PUSCH configured. Since RRC signaling may be quite slow, for dynamic configuration, commands to switch to/from DFT-S-OFDM may be sent in DCI scheduling PUSCH or setting or activating CG. In other words, the DCI may indicate uplink resources to be used by the communication device to transmit the second uplink signal, or the DCI may be an activation DCI indicating that unlicensed resources, which the communication device is able to transmit signals to a cell of the wireless communication network, are activated or deactivated. To this end, it may be necessary to add additional bits to the scheduling/activation DCI. Those skilled in the art will note that this selection may have significant regulatory impact.

Those skilled in the art should note that in an arrangement of embodiments of the present technology in which a UE can determine that it should switch waveforms based on an indication received from the network, such an indication can be received based on the UE being out of good coverage (i.e., it is in DL coverage but not in good UL coverage, for example because it is based on being at the cell edge) or based on the UE being completely outside of UL coverage. In other words, the indication may be received by the communication device from a cell of the wireless communication network in response to the communication device moving outside of a region of good coverage of the cell of the wireless communication network or in response to the communication device moving completely outside of a region of coverage of the cell of the wireless communication network. In some other arrangements of embodiments of the present technology, the indication may be received before the UE is out of coverage so that the UE knows that when it detects at a later time that it has been out of coverage, it should switch to the second waveform (e.g. DFT-S-OFDM) without having to wait for further instructions from the network. In other words, the indication may be received by the communication device from a cell of the wireless communication network before the communication device moves outside an uplink coverage area of the cell of the wireless communication network.

Fig. 6 shows a flow chart illustrating an example process of communication in a communication system in accordance with an embodiment of the present technology. The process shown in fig. 6 is a method of operating a communication device.

The method starts in step S1. The method comprises, in step S2, transmitting a first uplink signal to a cell of the wireless communication network based on a first waveform type. In step S3, the method includes determining that the communication device is to transmit a second uplink signal based on a second waveform type other than the first waveform type, based on the predetermined condition being satisfied. Then, in step S4, the process includes transmitting a second uplink signal to a cell of the wireless communication network based on the second waveform type. Here, the predetermined condition may include (or instruct) the communication device to move outside of an uplink coverage area of a cell of the wireless communication network. The process ends at step S5.

Those skilled in the art will appreciate that the method illustrated in fig. 6 may be modified in accordance with embodiments of the present technique. For example, other intermediate steps may be included in the method, or steps may be performed in any logical order. Although embodiments of the present technology have been described primarily with respect to the example communication system shown in fig. 5, it should be apparent to those skilled in the art that embodiments of the present technology may be equally applied to other systems described herein.

Those skilled in the art will further appreciate that such infrastructure equipment and/or communications devices as defined herein may be further defined in accordance with the various arrangements and embodiments discussed in the preceding paragraphs. Those skilled in the art will also appreciate that such infrastructure equipment and communications devices as defined and described herein may form part of a communications system other than that defined by the present disclosure.

The following numbered paragraphs provide additional example aspects and features of the present technology:

Paragraph 1. A method of operating a communication device, the method comprising:

transmitting a first uplink signal to a cell of the wireless communication network based on the first waveform type,

Determining that the communication device is to transmit a second uplink signal based on a second waveform type other than the first waveform type based on satisfying the predetermined condition, and

A second uplink signal is transmitted to a cell of the wireless communication network based on the second waveform type.

Paragraph 2. The method of paragraph 1 wherein the predetermined condition comprises the communication device moving outside of an uplink coverage area of a cell of the wireless communication network.

Paragraph 3. The method of paragraph 1 or paragraph 2, comprising:

Based on meeting the predetermined condition, autonomously determining that the communication device is to transmit the second uplink signal based on the second waveform type instead of the first waveform type.

Paragraph 4. The method according to any of paragraphs 1 to 3, comprising:

Receiving an indication from a cell of the wireless communication network that the communication device is to transmit a second uplink signal based on a second waveform type, and

Based on the predetermined condition being met, based on the received indication, it is determined that the communication device is to transmit a second uplink signal based on the second waveform type instead of the first waveform type.

Paragraph 5. The method of paragraph 4, wherein the indication is received by the communication device in downlink control information, DCI, from a cell of the wireless communication network.

Paragraph 6. The method of paragraph 5, wherein the DCI indicates uplink resources to be used by the communication device to transmit the second uplink signal.

Paragraph 7. The method of paragraph 5 or paragraph 6 wherein the DCI is an activation DCI indicating that an unlicensed resource of the communication device is capable of transmitting signals to a cell of the wireless communication network in the unlicensed resource is activated or deactivated.

A method according to any of paragraphs 4 to 7, wherein the indication is received by the communication device from a cell of the wireless communication network in a control signal indicating that the communication device initiates a random access RACH procedure with the cell of the wireless communication network, and wherein the second uplink signal is a message of the RACH procedure.

A method according to any of paragraphs 9, wherein the indication is received by the communication device from a cell of the wireless communication network in semi-static signaling.

Paragraph 10. The method of paragraph 9 wherein the semi-static signaling is radio resource control, RRC, signaling.

Paragraph 11. The method of any of paragraphs 4 to 10, wherein the indication comprises an instruction for the communication device to initiate a random access RACH procedure with a cell of the wireless communication network, and wherein the second uplink signal is a message of the RACH procedure.

Paragraph 12. The method of any of paragraphs 4 to 11, wherein the indication is carried by a medium access control, MAC, control element.

Paragraph 13. The method of any of paragraphs 4 to 12, wherein the indication is received by the communication device from a cell of the wireless communication network in response to the communication device moving outside of an area of good coverage of the cell of the wireless communication network.

The method of any of paragraphs 4 to 13, wherein the indication is received by the communication device from a cell of the wireless communication network in response to the communication device moving completely outside of an area of coverage of the cell of the wireless communication network.

A method according to any of paragraphs 15, wherein the indication is received by the communication device from a cell of the wireless communication network before the communication device moves outside an uplink coverage area of the cell of the wireless communication network.

Paragraph 16. The method of any of paragraphs 4 to 15 wherein the first uplink signal is a first message initiated by the communication device with a random access RACH procedure of a cell of the wireless communication network.

Paragraph 17. The method of paragraph 16, comprising:

Determining that the first uplink signal has not been successfully received by a cell of the wireless communication network, an

The first uplink signal is retransmitted one or more times until it is determined that the first uplink signal has been successfully received by a cell of the wireless communication network, wherein a transmission power of each retransmission of the first uplink signal is increased relative to a previous transmission of the first uplink signal.

The method of paragraph 17, wherein the indication is received by the communication device from a cell of the wireless communication network based on a preamble used by the communication device to retransmit a first uplink signal, the first uplink signal successfully received by the cell of the wireless communication network, the preamble from a set of one or more preambles associated with a transmission power above a specified threshold power.

Paragraph 19. The method according to any of paragraphs 16 to 18, comprising:

Retransmitting the first uplink signal one or more times until it is determined that the first uplink signal has been successfully received by a cell of the wireless communication network, wherein a RACH occasion for each retransmission of the first uplink signal changes relative to a previous transmission of the first uplink signal,

Wherein the indication is received by the communication device from a cell of the wireless communication network based on a RACH occasion used by the communication device to retransmit a first uplink signal that was successfully received by the cell of the wireless communication network.

Paragraph 20. The method according to any of paragraphs 16 to 19, comprising:

Retransmitting the first uplink signal one or more times until it is determined that the first uplink signal has been successfully received by a cell of the wireless communication network,

Wherein the indication is received by the communication device from a cell of the wireless communication network based on a number of retransmissions performed by the communication device before determining that the first uplink signal has been successfully received by the cell of the wireless communication network being above a specified threshold.

A method according to any of paragraphs 16 to 20, wherein the indication is received by the communication device from a cell of the wireless communication network within a random access response, RAR, message responsive to the first message of the RACH procedure, wherein the indication is carried by reserved bits of the RAR message.

Paragraph 22. The method according to any of paragraphs 16 to 21, comprising:

The first uplink signal is retransmitted one or more times according to the multiple PRACH transmission mode,

Wherein the indication is received by the communication device from a cell of the wireless communication network based on a number of retransmissions used in the multiple PRACH transmission of the first message for the RACH procedure being above a specified threshold.

The method of any of paragraphs 23, wherein the indication is received by the communication device from a cell of the wireless communication network based on the communication device transmitting a first uplink signal having a preamble selected from a predetermined set of preambles.

A method according to any of paragraphs 4 to 23, wherein the indication is received by the communication device from a cell of the wireless communication network based on the communication device transmitting the first uplink signal in RACH occasions of a predetermined set of RACH occasions.

A method according to any of paragraphs 1 to 24, wherein the first uplink signal is a first message of a random access RACH procedure with a cell of the wireless communication network initiated by the communication device, and wherein the method comprises:

It is determined that the first uplink signal has not been successfully received by a cell of the wireless communication network,

Retransmitting the first uplink signal one or more times, wherein a transmission power of each retransmission of the first uplink signal is increased relative to a previous transmission of the first uplink signal, and

Based on the transmission power of one of the retransmissions of the first uplink signal being above a specified threshold power, it is determined that the communication device is to transmit the second uplink signal based on the second waveform type instead of the first waveform type.

A method according to any of paragraphs 1 to 25, wherein the first uplink signal is a first message of a random access RACH procedure with a cell of a wireless communication network initiated by the communication device, and wherein the method comprises:

Based on the transmission power of one of the transmissions of the first uplink signal being above a specified threshold power, it is determined that the communication device is to transmit the second uplink signal based on the second waveform type instead of the first waveform type.

A method according to any one of paragraphs 27, wherein the second waveform type is discrete fourier transform spread orthogonal frequency division multiplexing, DFT-S-OFDM.

Paragraph 28. A communication device comprising:

transceiver circuitry, and

Controller circuitry configured in combination with transceiver circuitry

To transmit a first uplink signal to a cell of the wireless communication network based on the first waveform type,

To determine that the communication device is to transmit a second uplink signal based on a second waveform type other than the first waveform type based on meeting the predetermined condition, and

Paragraph 29. Circuitry for a communication device, comprising:

transceiver circuitry, and

Controller circuitry configured in combination with transceiver circuitry

Paragraph 30. A method of operating an infrastructure device forming part of a first wireless communications network, the method comprising:

Based on the first waveform type, a first uplink signal is received from the communication device,

A second uplink signal is received from the communication device based on the second waveform type.

Paragraph 31. The method of paragraph 30 wherein the predetermined condition comprises the communication device moving outside of an uplink coverage area of a cell of the wireless communication network formed by the infrastructure equipment.

Paragraph 32. The method of either paragraph 30 or paragraph 31, comprising transmitting to the communication device an indication that the communication device is to transmit a second uplink signal based on the second waveform type.

Paragraph 33. The method of paragraph 32 wherein the indication is transmitted by the infrastructure equipment to the communication device in downlink control information, DCI.

Paragraph 34. The method of paragraph 33 wherein the DCI indicates uplink resources to be used by the communication device to transmit the second uplink signal.

Paragraph 35. The method of either paragraph 33 or paragraph 34 wherein the DCI is an activation DCI indicating that an unlicensed resource of the communications apparatus is capable of transmitting a signal to the infrastructure equipment among the unlicensed resources is activated or deactivated.

A method according to any of paragraphs 32 to 35, wherein the indication is transmitted by the infrastructure equipment to the communication device in a control signal that instructs the communication device to initiate a random access RACH procedure with the infrastructure equipment, and wherein the second uplink signal is a message of the RACH procedure.

Paragraph 37. The method of any of paragraphs 32 to 36, wherein the indication is transmitted by the infrastructure equipment to the communication device in semi-static signaling.

Paragraph 38. The method of paragraph 37 wherein the semi-static signaling is radio resource control, RRC, signaling.

Paragraph 39. The method according to any of paragraphs 32 to 38, wherein the indication comprises an instruction for the communication device to initiate a random access RACH procedure with the infrastructure equipment, and wherein the second uplink signal is a message of the RACH procedure.

The method of any of paragraphs 32 to 39, wherein the indication is carried by a medium access control, MAC, control element.

Paragraph 41. The method of any of paragraphs 32 to 40, wherein the indication is transmitted by the infrastructure equipment to the communication device in response to the communication device moving completely outside the area of coverage of the infrastructure equipment.

Paragraph 42. The method of any of paragraphs 32 to 41, wherein the indication is transmitted by the infrastructure equipment to the communication device in response to the communication device moving outside of an area of good coverage of the infrastructure equipment.

Paragraph 43. The method of any of paragraphs 32 to 42, wherein the indication is transmitted by the infrastructure equipment to the communication device before the communication device moves to an uplink coverage area of the infrastructure equipment.

Paragraph 44. The method according to any of paragraphs 32 to 43, wherein the first uplink signal is a first message initiated by the communication device with a random access RACH procedure of the infrastructure equipment.

Paragraph 45. The method of paragraph 44, comprising:

The method includes receiving a first uplink signal from a communication device as a successfully received retransmission of one or more retransmissions of the first uplink signal, wherein a transmission power of each retransmission of the first uplink signal is increased at the communication device relative to a previous transmission of the first uplink signal.

Paragraph 46. The method of paragraph 45, wherein the indication is transmitted by the infrastructure equipment to the communication device based on a preamble of the retransmission used by the communication device for successful reception, the preamble being from a set of one or more preambles associated with a transmission power above a specified threshold power.

Paragraph 47. The method according to any of paragraphs 44 to 46, comprising

The first uplink signal is received from the communication device as a successfully received retransmission of the one or more retransmissions of the first uplink signal, wherein the RACH occasion for each retransmission of the first uplink signal is changed relative to the previous transmission of the first uplink signal,

Wherein the indication is transmitted by the infrastructure equipment to the communication device based on RACH occasions of the transmission used by the communication device for successful reception.

Paragraph 48. The method according to any of paragraphs 44 to 47, comprising

The first uplink signal is received from the communication device as a successfully received retransmission of the one or more retransmissions of the first uplink signal,

Wherein the indication is transmitted by the infrastructure equipment to the communication device based on the number of retransmissions determined by the infrastructure equipment that have been performed by the communication device prior to the successfully received retransmission being above a specified threshold.

A method according to any of paragraphs 32 to 48, wherein the indication is transmitted by the infrastructure equipment to the communication device based on the communication device transmitting a first uplink signal having a preamble selected from a predetermined set of preambles.

Paragraph 50. The method of any of paragraphs 32 to 49, wherein the indication is transmitted by the infrastructure equipment to the communication device based on the communication device transmitting a first uplink signal in a RACH occasion from a predetermined set of RACH occasions.

Paragraph 51. The method according to any of paragraphs 32 to 50, comprising

It is determined that a number of retransmissions of the first uplink signal performed by the communication device according to the multiple PRACH transmission mode is above a specified threshold,

Wherein the indication is transmitted by the infrastructure equipment to the communication device based on the number of retransmissions used in the multiple PRACH transmission of the first message for the RACH procedure being above a specified threshold.

Paragraph 52. The method according to any of paragraphs 32 to 51, wherein the indication is transmitted by the infrastructure equipment to the communication device within a random access response, RAR, message that is responsive to the first message of the RACH procedure, wherein the indication may be carried by reserved bits of the RAR message.

Paragraph 53. The method of any of paragraphs 30 to 52, comprising

It is determined that the first uplink signal is a first message of a random access RACH procedure initiated by the communication device with a cell of the wireless communication network.

The second signal is received by blindly decoding the second signal according to each of the first waveform type and the second waveform type.

Paragraph 54. The method according to any of paragraphs 30 to 53, wherein the second waveform type is discrete fourier transform spread orthogonal frequency division multiplexing, DFT-S-OFDM.

Paragraph 55. An infrastructure equipment forming part of a first wireless communication network, the infrastructure equipment comprising:

transceiver circuitry, and

Controller circuitry configured in combination with transceiver circuitry

To receive a first uplink signal from a communication device based on a first waveform type,

To receive a second uplink signal from the communication device based on the second waveform type.

Paragraph 56. Circuitry of an infrastructure equipment forming part of a first wireless communications network, the infrastructure equipment comprising

Transceiver circuitry, and

Controller circuitry configured in combination with transceiver circuitry

Paragraph 57. A wireless communication system comprising the communication apparatus of paragraph 28 and the infrastructure equipment of paragraph 55.

Paragraph 58. A computer program comprising instructions which, when loaded onto a computer, cause the computer to perform the method according to any of paragraphs 1 to 27 or paragraphs 30 to 54.

Paragraph 59. A non-transitory computer readable storage medium storing a computer program according to paragraph 58.

It will be appreciated that for clarity, the above description has described embodiments with reference to different functional units, circuitry and/or processors. However, it will be apparent that any suitable distribution of functionality between different functional units, circuitry and/or processors may be used without detracting from the implementation.

The described embodiments may be implemented in any suitable form including hardware, software, firmware or any combination of these. The described embodiments may optionally be implemented at least partly as computer software running on one or more data processors and/or digital signal processors. The elements and components of any embodiment may be physically, functionally and logically implemented in any suitable way. Indeed the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. Thus, the disclosed embodiments may be implemented in a single unit or may be physically and functionally distributed between different units, circuits and/or processors.

Although the present disclosure has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. In addition, while a feature may appear to be described in connection with particular embodiments, one skilled in the art will recognize that various features of the described embodiments may be combined in any manner suitable to implement the technology.

Reference to the literature

[1]Holma H.and Toskala A,"LTE for UMTS OFDMA and SC-FDMA based radio access",John Wiley and Sons,2009.

[2]TR 38.913,"3rd Generation Partnership Project;Technical Specification Group Radio Access Network;Study on Scenarios and Requirements for Next Generation Access Technologies(Release 14)",3GPP,vl4.3.0,August 2017.

[3]TS 38.214,"3rd Generation Partnership Project;Technical Specification Group Radio Access Network;NR;Physical layer procedures for data(Release 15)",3GPP,vl5.16.0,March 2022.

Claims

1. A method of operating a communication device, the method comprising:

transmitting a first uplink signal to a cell of a wireless communication network based on a first waveform type,

determining that the communication device is to transmit a second uplink signal based on a second waveform type instead of the first waveform type based on satisfying a predetermined condition, the second waveform type being different from the first waveform type, and

The second uplink signal is transmitted to the cell of the wireless communication network based on the second waveform type.

2 . The method according to claim 1 , wherein the predetermined condition comprises the communication device moving out of an uplink coverage area of the cell of the wireless communication network.

3. The method of claim 1 , comprising autonomously determining that the communications device is to transmit the second uplink signal based on the second waveform type instead of the first waveform type based on satisfying the predetermined condition.

4. The method according to claim 1, comprising:

receiving, from the cell of the wireless communication network, an indication that the communication device is to transmit the second uplink signal based on the second waveform type, and

Based on satisfying the predetermined condition, based on the received indication, it is determined that the communications device is to transmit the second uplink signal based on the second waveform type instead of the first waveform type.

5 . The method of claim 4 , wherein the indication is received by the communication device from the cell of the wireless communication network in downlink control information (DCI).

The method of claim 5 , wherein the DCI indicates uplink resources to be used by the communication device to transmit the second uplink signal.

7 . The method according to claim 5 , wherein the DCI is an activation DCI indicating that the unlicensed resources in which the communication device can transmit a signal to the cell of the wireless communication network in the unlicensed resources are activated or deactivated.

8. The method of claim 4, wherein the indication is received by the communication device from the cell of the wireless communication network in a control signal, the control signal instructing the communication device to initiate a random access (RACH) procedure with the cell of the wireless communication network, and wherein the second uplink signal is a message of the RACH procedure.

9. The method of claim 4, wherein the indication is received by the communication device from the cell of the wireless communication network in semi-static signaling.

10. The method according to claim 9, wherein the semi-static signaling is Radio Resource Control (RRC) signaling.

11. The method of claim 4, wherein the indication comprises an instruction for the communication device to initiate a random access (RACH) procedure with the cell of the wireless communication network, and wherein the second uplink signal is a message of the RACH procedure.

12. The method of claim 4, wherein the indication is carried by a medium access control (MAC) control element.

13. The method of claim 4, wherein the indication is received by the communication device from the cell of the wireless communication network in response to the communication device moving outside an area of good coverage of the cell of the wireless communication network.

14. The method of claim 4, wherein the indication is received by the communication device from the cell of the wireless communication network in response to the communication device moving completely out of an area of coverage of the cell of the wireless communication network.

15. The method of claim 4, wherein the indication is received by the communication device from the cell of the wireless communication network before the communication device moves outside the uplink coverage area of the cell of the wireless communication network.

16. The method according to claim 4, wherein the first uplink signal is a first message of a random access (RACH) procedure initiated by the communication device with the cell of the wireless communication network.

17. The method according to claim 16, comprising:

determining that the first uplink signal has not been successfully received by a cell of the wireless communication network, and

The first uplink signal is retransmitted one or more times until it is determined that the first uplink signal has been successfully received by the cell of the wireless communication network, wherein the transmission power of each retransmission of the first uplink signal is increased relative to a previous transmission of the first uplink signal.

18. A method according to claim 17, wherein the indication is received by the communication device from the cell of the wireless communication network based on a preamble code used by the communication device to retransmit the first uplink signal, and the first uplink signal is successfully received by the cell of the wireless communication network, and the preamble code is from a set of one or more preamble codes associated with a transmission power higher than a specified threshold power.

19. The method according to claim 16, comprising:

retransmitting the first uplink signal one or more times until it is determined that the first uplink signal has been successfully received by the cell of the wireless communication network, wherein a RACH timing for each retransmission of the first uplink signal is changed relative to a previous transmission of the first uplink signal,

The indication is received by the communication device from the cell of the wireless communication network based on a RACH opportunity used by the communication device to retransmit the first uplink signal, and the first uplink signal is successfully received by the cell of the wireless communication network.

20. The method according to claim 16, comprising:

determining that the first uplink signal has not been successfully received by the cell of the wireless communication network, and

retransmitting the first uplink signal one or more times until it is determined that the first uplink signal has been successfully received by the cell of the wireless communication network,

wherein the indication is received by the communication device from the cell of the wireless communication network based on the number of retransmissions performed by the communication device before determining that the first uplink signal has been successfully received by the cell of the wireless communication network being higher than a specified threshold.

21. The method of claim 16, wherein the indication is received by the communication device from the cell of the wireless communication network in a random access response (RAR) message in response to the first message of the RACH procedure, wherein the indication is carried by a reserved bit of the RAR message.

22. The method according to claim 16, comprising:

retransmitting the first uplink signal one or more times according to a multi-PRACH transmission mode,

The indication is received by the communication device from the cell of the wireless communication network based on the number of retransmissions used in the multiple PRACH transmission of the first message for the RACH process being higher than a specified threshold.

23. The method of claim 4, wherein the indication is received by the communication device from the cell of the wireless communication network based on the communication device transmitting the first uplink signal having a preamble selected from a predetermined set of preambles.

24. The method of claim 4, wherein the indication is received by the communication device from the cell of the wireless communication network based on the communication device transmitting the first uplink signal in a RACH opportunity from a predetermined set of RACH opportunities.

25. The method according to claim 1, wherein the first uplink signal is a first message of a random access RACH procedure initiated by the communication device with the cell of the wireless communication network, and wherein the method comprises:

determining that the first uplink signal has not been successfully received by the cell of the wireless communication network,

retransmitting the first uplink signal one or more times, wherein the transmission power of each retransmission of the first uplink signal is increased relative to a previous transmission of the first uplink signal, and

Based on the transmission power of one of the retransmissions of the first uplink signal being above a specified threshold power, it is determined that the communications device is to transmit the second uplink signal based on the second waveform type instead of the first waveform type.

26. The method according to claim 1, wherein the first uplink signal is a first message of a random access RACH procedure initiated by the communication device with the cell of the wireless communication network, and wherein the method comprises:

Based on the transmission power of one of the transmissions of the first uplink signal being above a specified threshold power, it is determined that the communications device is to transmit the second uplink signal based on the second waveform type instead of the first waveform type.

27. The method of claim 1, wherein the second waveform type is discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM).

28. A communication device, comprising:

transceiver circuitry, and

A controller circuit system configured in combination with the transceiver circuit system

29. A circuit system for a communication device, comprising:

transceiver circuitry, and

30. A method of operating infrastructure equipment forming part of a first wireless communication network, the method comprising:

receiving a first uplink signal from a communication device based on a first waveform type,

The second uplink signal is received from the communication device based on the second waveform type.

31. The method of claim 30, wherein the predetermined condition comprises the communication device moving outside an uplink coverage area of a cell of the wireless communication network formed by the infrastructure equipment.

32. The method of claim 30, comprising:

An indication is transmitted to the communications device that the communications device is to transmit the second uplink signal based on the second waveform type.

33. The method of claim 32, wherein the indication is transmitted by the infrastructure equipment to the communication device in downlink control information (DCI).

34. The method of claim 33, wherein the DCI indicates uplink resources to be used by the communication device to transmit the second uplink signal.

35 . The method of claim 33 , wherein the DCI is an activation DCI indicating that the unlicensed resources in which the communication apparatus can transmit a signal to the infrastructure equipment are activated or deactivated.

36. The method of claim 32, wherein the indication is transmitted by the infrastructure equipment to the communication device in a control signal, the control signal instructing the communication device to initiate a random access (RACH) procedure with the infrastructure equipment, and wherein the second uplink signal is a message of the RACH procedure.

37. The method of claim 32, wherein the indication is transmitted by the infrastructure equipment to the communication device in semi-static signaling.

38. The method of claim 37, wherein the semi-static signaling is Radio Resource Control (RRC) signaling.

39. The method of claim 32, wherein the indication comprises an instruction for the communication device to initiate a random access (RACH) procedure with the infrastructure equipment, and wherein the second uplink signal is a message of the RACH procedure.

40. The method of claim 32, wherein the indication is carried by a Medium Access Control (MAC) control element.

41. The method of claim 32, wherein the indication is transmitted by the infrastructure equipment to the communication device in response to the communication device moving completely outside of an area of coverage of the infrastructure equipment.

42. The method of claim 32, wherein the indication is transmitted by the infrastructure equipment to the communication device in response to the communication device moving outside an area of good coverage of the infrastructure equipment.

43. The method of claim 32, wherein the indication is transmitted by the infrastructure equipment to the communication device before the communication device moves into the uplink coverage area of the infrastructure equipment.

44. The method of claim 32, wherein the first uplink signal is a first message of a random access (RACH) procedure initiated by the communication device with the infrastructure equipment.

45. The method of claim 44, comprising:

The first uplink signal is received from the communication device as a successfully received retransmission among one or more retransmissions of the first uplink signal, wherein the transmission power of each retransmission of the first uplink signal is increased at the communication device relative to the previous transmission of the first uplink signal.

46. A method according to claim 45, wherein the indication is transmitted by the infrastructure equipment to the communication device based on a preamble code used by the communication device for the successfully received retransmission, and the preamble code is from a set of one or more preamble codes associated with a transmission power above a specified threshold power.

47. The method of claim 44, comprising:

receiving, from the communication device, the first uplink signal as a successfully received retransmission among one or more retransmissions of the first uplink signal, wherein a RACH timing for each retransmission of the first uplink signal is changed relative to a previous transmission of the first uplink signal,

Wherein the indication is transmitted by the infrastructure equipment to the communication device based on the RACH opportunity used by the communication device for the successfully received transmission.

48. The method of claim 44, comprising:

receiving the first uplink signal from the communication device as a successfully received retransmission among one or more retransmissions of the first uplink signal,

wherein the indication is transmitted by the infrastructure equipment to the communication device based on a number of retransmissions determined by the infrastructure equipment to have been performed by the communication device prior to the successfully received retransmission being above a specified threshold.

49. The method of claim 32, wherein the indication is transmitted by the infrastructure equipment to the communications device based on the communications device transmitting the first uplink signal having a preamble selected from a predetermined set of preambles.

50. The method of claim 32, wherein the indication is transmitted by the infrastructure equipment to the communications device based on the communications device transmitting the first uplink signal in a RACH opportunity from a predetermined set of RACH opportunities.

51. The method of claim 32, comprising:

determining that a number of retransmissions of the first uplink signal performed by the communication device according to the multi-PRACH transmission mode is higher than a specified threshold,

Wherein, the indication is transmitted by the infrastructure equipment to the communication device based on the number of retransmissions used in the multiple PRACH transmission of the first message for the RACH procedure being higher than the specified threshold.

52. The method of claim 32, wherein the indication is transmitted by the infrastructure equipment to the communication device in a random access response (RAR) message in response to the first message of the RACH procedure, wherein the indication is carried by a reserved bit of the RAR message.

53. The method of claim 30, comprising:

determining that the first uplink signal is a first message of a random access RACH procedure initiated by the communication device to a cell of the wireless communication network, and

The second signal is received by blindly decoding a second signal according to each of the first waveform type and the second waveform type.

54. The method of claim 30, wherein the second waveform type is discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM).

55. Infrastructure equipment forming part of a first wireless communication network, the infrastructure equipment comprising:

transceiver circuitry, and

receiving a first uplink signal from a communication device based on a first waveform type, determining that the communication device is to transmit a second uplink signal based on a second waveform type other than the first waveform type based on satisfaction of a predetermined condition, the second waveform type being different from the first waveform type, and

56. A circuit system of infrastructure equipment forming part of a first wireless communication network, the infrastructure equipment comprising:

transceiver circuitry, and

57. A wireless communication system comprising the communication apparatus according to claim 28 and the infrastructure equipment according to claim 55.

58. A computer program comprising instructions which, when loaded onto a computer, cause the computer to perform the method according to claim 1 or claim 30.

59. A non-transitory computer-readable storage medium storing the computer program according to claim 58.