Method, communication device and infrastructure equipment

Abstract

A method of operating a communication device is provided. The method comprises transmitting a first uplink signal to a cell of the wireless communication network based on a first waveform type; determining, based on a predetermined condition being satisfied, that the communication device is to transmit a second uplink signal based on a second waveform type, which is different from the first waveform type, rather than the first waveform type; and 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 may otherwise indicate) movement of the communication device out of an uplink coverage area of a cell of the wireless communication network.

Description

Background Art Technical Field

[0001] The present disclosure relates to communication devices, infrastructure equipment, and methods for more efficient operation of communication devices and infrastructure equipment in a wireless communication network.

[0002] This application claims the Paris Convention priority of European patent application No. EP22199303.3 filed on September 30, 2022, the contents of which are incorporated herein by reference.

[0003] Description of Related Art

[0004] The "background technology" description provided herein is for the purpose of generally presenting the context of the present disclosure. The work of the presently named inventors, within the scope described in this background technology section and in aspects that may not be described as prior art at the time of filing, is neither explicitly nor implicitly admitted to be prior art with respect to the present invention.

[0005] Previous generation mobile telecommunication systems (such as those based on the UMTS and Long Term Evolution (LTE) architectures defined by 3GPP) are able to support a wider range of services beyond the simple voice and messaging services provided by previous generations of mobile telecommunication systems. For example, with the improved radio interface and enhanced data rates provided by LTE systems, users are able to enjoy high data rate applications that were previously only available via fixed line data connections, such as mobile video streaming and mobile video conferencing. Therefore, there is a strong demand to deploy such networks, and it is expected that the coverage areas of these networks (i.e., the geographic locations where the networks can be accessed) will continue to grow rapidly.

[0006] Current and future wireless communication networks are expected to routinely and efficiently support communications with an ever-increasing range of devices associated with a wider range of data traffic 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 communications with devices including reduced complexity devices, machine type communication (MTC) devices, high-resolution video displays, virtual reality headsets, extended reality (XR), etc. Some of these different types of devices may be deployed in very large numbers, such as low-complexity devices used to support the "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 streaming, may be associated with the transmission of relatively large amounts of data with relatively low latency tolerance. Other types of devices, such as those used 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 smartphone when the smartphone is running a video streaming application (high downlink data) as compared to when the smartphone is running an Internet browsing application (sporadic uplink and downlink data) or is being used by emergency responders for voice communications in an emergency scenario (data subject to strict reliability and latency requirements).

[0007] In view of this, it is expected that current wireless communication networks (such as those that may be referred to as 5G or New Radio (NR) systems / new radio access technology (RAT) systems or indeed future 6G wireless communications) will need to efficiently support connections for a wide range of devices associated with different applications and different characteristic data traffic profiles and requirements.

[0008] One example of a new service is called an ultra-reliable low-latency communication (URLLC) service, which, as its name indicates, requires the transmission of data units or packets with high reliability and low communication delay. Another example of a new service is an enhanced mobile broadband (eMBB) service, characterized by high capacity, requiring support of up to 20Gb / s. Therefore, URLLC and eMBB type services are challenging examples for both LTE type communication systems and 5G / NR communication systems.

[0009] 5G NR continues to evolve and the current work plan includes 5G-NR-advanced, where several further enhancements are expected, especially to support new use cases / scenarios with higher requirements. The desire to support these new use cases and scenarios brings new challenges that need to be addressed for efficient handling of communications in wireless communication systems. Summary of the invention

[0010] The present disclosure may help to solve or mitigate at least some of the problems discussed above.

[0011] 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 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 the communication device moving outside the uplink coverage area of ​​the cell of the wireless communication network.

[0012] In addition to methods of operating communication devices, embodiments of the present technology also relate to methods of operating infrastructure equipment, communication devices and infrastructure equipment, circuit systems for communication devices and infrastructure equipment, computer programs and computer-readable storage media that can allow more efficient use of radio resources by communication devices operating in a wireless communication network.

[0013] Accordingly aspects and features of the disclosure are defined in the appended claims.

[0014] It should be understood that both the foregoing general description and the following detailed description are exemplary, rather than limiting, of the present 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] A more complete understanding of the present disclosure and many of its attendant advantages will be readily appreciated as they become better appreciated by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference numerals refer to identical or corresponding parts throughout the several views, and in which:

[0016] Figure 1 schematically represents some aspects of an LTE-type wireless telecommunications system that may be configured to operate in accordance with certain embodiments of the present disclosure;

[0017] Figure 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;

[0018] Figure 3 is a schematic block diagram of example infrastructure equipment and communications devices that may be configured to operate in accordance with certain embodiments of the present disclosure;

[0019] Figure 4A and Figure 4B illustrates how initial access and / or uplink small data transfer (SDT) may be performed by a user equipment (UE) using a random access (RACH) scheme when the UE is in an idle or inactive state;

[0020] Figure 5 A partially schematic, partial message flow diagram representation of a wireless communication system including a communication apparatus and infrastructure equipment according to an embodiment of the present technology is shown; and

[0021] Figure 6 A flow chart is shown that illustrates the processing of communications in a communication system according to an embodiment of the present technology. DETAILED DESCRIPTION

[0022] Long Term Evolution Advanced Radio Access Technology (4G)

[0023] Figure 1 A schematic diagram is provided illustrating certain basic functionality of a mobile telecommunication network / system 6, which typically operates according to LTE principles, but which may also support other radio access technologies, and which may be adapted to implement embodiments of the present disclosure as described herein. Figure 1 Certain aspects of the various elements of the telecommunications network and their corresponding modes of operation are well known and defined in relevant standards managed by the 3GPP (RTM) body and are also described in a number of books on the subject (e.g., Holma H. ​​and Toskala A [1]). It will be appreciated that operational aspects of the telecommunications network discussed herein that are not specifically described (e.g., with respect to specific communication protocols and physical channels used for communication between the different elements) may be implemented in accordance with any known techniques (e.g., in accordance with relevant standards and known proposed modifications and additions to relevant standards).

[0024] The network 6 comprises a plurality of base stations 1 connected to a core network 2. Each base station provides a coverage area 3 (ie a cell) within which data can be communicated to and from a communication device 4. Figure 1 Each base station 1 is shown as a single entity in the figure, but those skilled in the art will understand that some functions of a base station may be performed by different interconnected elements, such as an antenna (or multiple antennas), a remote radio head, amplifiers, etc. One or more base stations may together form a radio access network.

[0025] Data is transmitted from the base station 1 to the communication device 4 within its corresponding coverage area 3 via a radio downlink (DL). Data is transmitted from the communication device 4 to the base station 1 via a radio uplink (UL). The core network 2 routes data to and from the communication device 4 via the corresponding base station 1, and provides functions such as authentication, mobility management, billing, etc. The terminal device may also be referred to as a mobile station, user equipment (UE), user terminal, mobile radio, communication device, etc. The services provided by the core network 2 may include a connection to the Internet or to an external telephone service. 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 toward the communication device 4.

[0026] Base stations, as examples of network infrastructure equipment, may also be referred to as transceiver stations, Node Bs, eNode Bs, eNBs, gNode Bs, gNBs, etc. In this regard, different terms are often associated with different generations of wireless telecommunication systems for elements that provide broadly comparable functionality. However, certain embodiments of the present disclosure may be implemented equally in different generations of wireless telecommunication systems, and for simplicity, certain terms may be used regardless of the underlying network architecture. That is, the use of a particular term for certain example implementations is not intended to indicate that these implementations are limited to only a certain generation of networks that may be most associated with that particular term.

[0027] New Radio Access Technology (5G)

[0028] 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 for up to 20 Gb / s. Ultra-reliable low latency communications (URLLC) services require a single transmission of a 32-byte packet from a radio protocol layer 2 / 3 SDU entry point to a radio protocol layer 2 / 3 SDU exit point of the radio interface within 1 ms, with a reliability of 1-10. -5 (99.999%) or higher (99.9999%)[2].

[0029] Massive machine type communication (mMTC) is another example of a service that can 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) to support services with new requirements for high availability, high reliability, low latency, and in some cases high precision positioning.

[0030] Figure 2 An example configuration of a wireless communication network using some terminology proposed for and used in NR and 5G is shown in FIG. Figure 2 In the figure, a plurality of transmission and reception points (TRPs) 10 are connected to distributed control units (DUs) 41, 42 via connection interfaces represented by lines 16. Each of the TRPs 10 is arranged to send and receive signals via a wireless access interface within the radio frequency bandwidth available to the wireless communication network. Therefore, within the range for performing radio communications via the wireless access interface, each of the TRPs 10 forms a cell of the wireless communication network as represented by circle 12. In this way, a wireless communication device 14 within the radio communication range provided by the cell 12 can send signals to and receive signals from the TRP 10 via the wireless access interface. Each of the distributed units 41, 42 is connected to a central unit (CU) 40 (which can be referred to as a control node) via an interface 46. The central unit 40 is then connected to a core network 20, which can contain all other functions required for transmitting data for transmission to and from the wireless communication devices, and the core network 20 can be connected to other networks 30.

[0031] Figure 2 The elements of the wireless access network shown may be similar to those described above. Figure 1 The corresponding elements of the LTE network described in the examples operate in a similar manner. It will be appreciated that Figure 2 The operational aspects of the presented telecommunications networks, as well as operational aspects of other networks not specifically described herein that are discussed in accordance with embodiments of the present disclosure (e.g., with respect to specific communication protocols and physical channels used for communication between different elements), may be implemented in accordance with any known technology (e.g., in accordance with currently used methods for implementing such operational aspects of wireless telecommunications systems, e.g., in accordance with relevant standards).

[0032] Figure 2 The TRP 10 of the new RAT network may have, in part, functionality corresponding to a base station or eNode B of an LTE network. Similarly, the communication device 14 may have functionality corresponding to a UE device 4 known for operating with an LTE network. It will therefore be understood that operational aspects of the new RAT network (e.g., with respect to specific communication protocols and physical channels used for communication between different elements) may differ from those operational aspects known from LTE or other known mobile telecommunication standards. However, it will also be understood that each of the core network components, base stations, and communication devices of the new RAT network will be functionally similar to the core network components, base stations, and communication devices of the LTE wireless communication network, respectively.

[0033] In terms of broad top-level functionality, connecting to Figure 2 The core network 20 of the presented new RAT telecommunication system can be broadly considered to be similar to Figure 1The core network 2 presented corresponds to the core network 2, and the corresponding central unit 40 and its associated distributed units / TRP 10 can be broadly considered to provide Figure 1 The term network infrastructure equipment / access node may be used to encompass these elements and more conventional base station type elements of wireless telecommunication systems. Depending on the application at hand, the responsibility for scheduling transmissions scheduled over the radio interface between the corresponding distributed units and the communication device may lie with the control node / central unit and / or the distributed unit / TRP. The communication device 14 is Figure 2 The communication device 14 is presented as being located within the coverage area of ​​the first communication cell 12. The communication device 14 can therefore 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.

[0034] You will also understand that Figure 2 Only one example of the proposed architecture for a new RAT based telecommunication system is presented, wherein the method according to the principles described herein may be employed, and in terms of wireless telecommunication systems having a different architecture the functionalities disclosed herein may also be applied.

[0035] Thus, certain embodiments of the present disclosure as discussed herein may be implemented according to a variety of different architectures, such as Figure 1 and Figure 2 The example architecture shown in FIG. 1 is implemented in a wireless telecommunications system / network. It will therefore 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 communications between network infrastructure equipment / access nodes and communication devices, wherein the particular nature of the network infrastructure equipment / access nodes and the communication devices will depend on the network infrastructure used for the implementation at hand. For example, in some scenarios, the network infrastructure equipment / access nodes may include a base station (such as, for example, Figure 1 The LTE type base station 1 shown is suitable for providing the functions according to the principles described herein, while in other examples, the network infrastructure equipment may include Figure 2 A control unit / control node 40 and / or TRP 10 of the type shown is suitable for providing functionality according to the principles described herein.

[0036] Figure 3 Provided Figure 2 A more detailed schematic diagram of some of the components of the network is shown. Figure 3 In the simplified presentation, Figure 2The illustrated TRP 10 includes a wireless transmitter 30, a wireless receiver 32, and a controller or control processor 34 that is 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. Figure 3 As shown, the exemplary UE 14 is shown to include a corresponding transmitter 49, a receiver 48 and a controller 44, which is configured to control the transmitter 49 and the 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 according to normal operation.

[0037] The transmitters 30, 49 and the receivers 32, 48 (as well as other transmitters, receivers, and transceivers described with respect to the examples and embodiments of the present disclosure) may include radio frequency filters and amplifiers as well as signal processing components and devices to transmit and receive radio signals according to, for example, the 5G / NR standard. The controllers 34, 44 (as well as other controllers described with respect to the examples and embodiments of the present disclosure) may be, for example, a microprocessor, a CPU, or a dedicated chipset configured to execute instructions stored on a computer-readable medium such as a non-volatile memory. The processing steps described herein may be performed, for example, by a microprocessor in combination with a random access memory, the microprocessor operating according to instructions stored on a computer-readable medium. For ease of presentation, the following are provided herein. Figure 3 The transmitter, receiver and controller are schematically shown as separate elements in the . However, it will be understood that the functionality of these elements may be provided in a variety of different ways, such as using one or more appropriately programmed programmable computers, or one or more appropriately configured application specific integrated circuits / circuitry / chips / chip sets. It will be understood that the infrastructure equipment / TRP / base station and UE / communication device will typically include various other elements associated with their operating functions.

[0038] like Figure 3 As shown, the TRP 10 also includes a network interface 50 that is connected to the DU 42 via the physical interface 16. Thus, the network interface 50 provides a communication link for data and signaling traffic from the TRP 10 via the DU 42 and the CU 40 to the core network 20.

[0039] The interface 46 between the DU 42 and the CU 40 is referred to as the F1 interface, which can be a physical interface or a logical interface. The F1 interface 46 between the CU and the DU can operate according to the specifications 3GPP TS 38.470 and 3GPP TS 38.473, and can be formed by optical fiber or other wired or wireless high-bandwidth connections. In one example, the connection 16 from the TRP 10 to the DU 42 is via optical fiber. The connection between the TRP 10 and the core network 20 can generally be referred to as a backhaul, which includes the interface 16 from the network interface 50 of the TRP 10 to the DU 42 and the F1 interface 46 from the DU 42 to the CU 40.

[0040] RACH procedure in LTE and NR

[0041] In wireless telecommunications networks (such as UTE and NR type networks), there are different radio resource control (RRC) modes for terminal devices. For example, it is common to support RRC idle mode (RRC_IDLE) and RRC_CONNECTED mode (RRC_CONNECTED). A terminal device in idle mode can transition to connected mode, for example because it needs to transmit uplink data or respond to a paging request by engaging in a random access procedure. The random access procedure involves the terminal device transmitting a preamble on a physical random access channel (PRACH), so the process is generally referred to as RACH or PRACH process / processing, where such a RACH process may include four steps or two steps, as described in more detail below.

[0042] 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 the RRC_INACTIVE state without first transitioning to the RRC_CONNECTED state with the network for reasons like performing a small data transfer (SDT).

[0043] In addition to the terminal device deciding to initiate a random access procedure itself to connect to the network, the network (e.g. a base station) may also instruct a 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.

[0044] There are various scenarios in which a network triggered RACH procedure (PDCCH command) may occur. For example:

[0045] The terminal device may receive a PDCCH order to transmit on the PRACH (as part of a handover procedure);

[0046] A terminal device that is RRC_CONNECTED with a base station but has not exchanged data with the base station for a relatively long time may receive a PDCCH command to cause the terminal device to transmit a RACH preamble so that it can resynchronize with the network and allow the base station to correct the timing of the terminal device;

[0047] A terminal device may receive a PDCCH command such that it may establish a different RRC configuration in a subsequent RACH procedure, which may for example be applied to narrowband IoT terminal devices that are blocked from RRC reconfiguration in connected mode, whereby sending the terminal device to idle mode via a PDCCH command allows the terminal device to be configured in a subsequent PRACH procedure, for example to configure the terminal device for a different coverage enhancement level (e.g. more or fewer repetitions).

[0048] For convenience, the term PDCCH command is used herein to refer to the signaling transmitted by the base station to instruct the terminal device to initiate the PRACH process regardless of the reason. 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 process, the PDCCH command referred to here may be an RRC connection reconfiguration instruction transmitted on the downlink shared channel / PDSCH.

[0049] When a PDCCH command is transmitted to a terminal device, the terminal device is assigned a PRACH preamble signature sequence for use in a subsequent PRACH procedure. This differs from a terminal device triggered PRACH procedure where the terminal device selects a preamble from a predefined set and can therefore be performed by coincident selection of the same preamble as another terminal device performing a PRACH procedure at the same time, thereby causing potential contention. Therefore, for a PRACH procedure initiated by a PDCCH command, there is no contention with other terminal devices undertaking a PRACH procedure at the same time, as the PRACH preamble of the terminal device of the PDCCH command is scheduled by the network / base station.

[0050] Figure 4A An example of a 4-step RACH based scheme is shown, and also how a mobile originated (MO) SDT can be initiated by such a scheme. When a UE wants or is commanded to perform an initial access, or when the UE has a UL SDT ready for transmission, it can initiate such a scheme. Figure 4A The 4-step RACH process shown includes the following steps:

[0051] · A UE in RRC IDLE or RRC_INACTIVE starts a message 1 (Msg1) transmission 50 of a physical random access (PRACH) preamble associated with a specific preamble ID, and may be selected by the UE from a set of preambles assigned for SDT in the current cell. When the gNB receives the preamble, it identifies the UE, and / or identifies the message 1 (Msg1) as an SDT initiation, and responds with a message 2 (Msg2);

[0052] The gNB transmits 51 (Msg2), which contains a Random Access Response (RAR) message in response to the RACH preamble transmitted as part of the initial access procedure, where the RAR includes the RACH preamble ID (RAPID), the UL Timing Alignment Command, the UL PUSCH schedule for message 3 (Msg3), and the temporary Cell Radio Network Temporary Identifier (C-RNTI);

[0053] UE transmits 52 (Msg3), which contains the temporary C-RNTI received in Msg2 to identify the 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 in the scheduled PUSCH);

[0054] The gNB then provides 53 contention resolution after identifying and acknowledging the UE that transmitted the preamble in the first step 50 via its temporary C-RNTI received in Msg2. In this step 53, if the UE transmitted any small data, DL and UL feedback or acknowledgment is transmitted;

[0055] ○ For UL feedback received from a UE by the gNB in ​​response to transmitting a DL PDSCH to the UE, a hybrid automatic repeat request acknowledgement is transmitted on the cell-specific physical uplink control channel (PUCCH) resources configured in the system information

[0056] (HARQ-ACK) (although it should be noted that from the third step 52 onwards the UE is already UL synchronised); and

[0057] o For DL ​​feedback received by the UE in response to transmitting UL (Msg3) in the third step 52, message 4 (Msg4) is received at the UE in the fourth step 53

[0058] is considered a positive confirmation; and

[0059] After the fourth step 53, if the UE was performing a RACH procedure for the purpose of initial access, the connection is now established and the UE now transitions to the RRC_CONNECTED state. Otherwise, if the UE was performing a RACH procedure for the purpose of SDT, the UE has now been identified by the network and is also UL synchronized. Therefore, if the UE was performing a small data transfer while in the RRC_INACTIVE state, subsequent UL and DL SDT with dynamic scheduling can occur 54 when required while the UE remains in the INACTIVE state. Likewise, if the UE is in RRC_CONNECTED at this time, it can transmit and receive data to and from the network either through dynamic scheduling or using configured grants. Later, once the SDT is completed and neither the gNB nor the UE has any further data to transmit, the gNB may choose to keep the UE in the RRC_INACTIVE state by sending an RRCRelease with a suspend indication 55.

[0060] Figure 4B An example of a 2-step RACH based scheme is shown, and also how MO SDT can be initiated by such a scheme. When a UE wants or is commanded to perform initial access, or has UL SDT ready for transmission, it can initiate such a scheme. Figure 4B The 2-step RACH process shown includes the following steps:

[0061] · A UE in RRC_IDLE or RRC_INACTIVE starts a msgA transmission 56 of a PRACH preamble associated with a specific preamble ID, and may be selected by the UE from a set of preambles assigned for SDT in the current cell, and the msgA also includes the associated PUSCH in the current cell (i.e. for SDT). If there is any remaining space in the PUSCH, the PUSCH contains RRC signaling (i.e. RRCConnectRequest for initial access or RRCResumeRequest for initiating SDT) and SDT

[0062] data;

[0063] Similar to the common 4-step RACH process, when the gNB receives 56msgA, it recognizes that the UE has initiated the RACH process and / or identifies it as SDT initiation and uses msgB

[0064] In response to 57, msgB contains the response to the RACH transmitted as part of the initial access procedure.

[0065] The preamble code of the random access response (RAR) message, where RAR includes RAPID, UL

[0066] The timing alignment command, C-RNTI and the identification and confirmation thereof are transmitted in the first step 56

[0067] UE contention resolution for msgA. In this step 57, DL and UL feedback or confirmation is transmitted;

[0068] o For UL feedback received by the gNB from a UE in response to a DL PDSCH transmitted by the gNB to the UE, HARQ-ACK is transmitted by the UE on the cell-specific PUCCH resources configured in the system information; and

[0069] o For DL ​​feedback received by a UE from a gNB in ​​response to transmission 56 of msgA by the UE, reception 57 of MsgB at the UE is considered a positive acknowledgement;

[0070] as well as

[0071] After the second step 57, if the UE is performing a RACH for the purpose of initial access

[0072] process, the connection is now established and the UE now transitions to RRC_CONNECTED

[0073] state. Otherwise, if the UE is performing a RACH procedure for the purpose of SDT, the UE has now been identified by the network and is also UL synchronized. Therefore, if the UE is performing a small data transfer while in the RRC_INACTIVE state, subsequent UL and DL SDT with dynamic scheduling can occur 58 when required while the UE remains in the INACTIVE state. Likewise, if the UE is in RRC_CONNECTED at this time, it can transmit data to and receive data from the network, typically through dynamic scheduling or using configured grants. Later, once the SDT is completed and neither the gNB nor the UE has any further data to transmit, the gNB may choose to keep the UE in the RRC_INACTIVE state by sending an RRCRelease with a suspend indication 59.

[0074] Configured authorization

[0075] As is well understood by those skilled in the art, the UE uses the Physical Uplink Shared Channel (PUSCH) for uplink data transmission. The PUSCH resources used for transmission of the PUSCH can be scheduled by the gNB using a dynamic grant (DG) or a configured grant (CG).

[0076] In Dynamic Grant PUSCH (DG-PUSCH), the UE typically sends a Scheduling Request (SR) to the gNB when uplink data arrives in its buffer. In response to receiving the SR, the gNB will then send an uplink grant to the UE using downlink control information (DCI), for example, using DCI format 0_0, 0_1, or 0_2 carried via the 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.

[0077] It is observed that the use of DG-PUSCH introduces latency as the UE needs to initiate an SR and has to wait for an uplink grant before it is scheduled with PUSCH resources. For regular and periodic traffic, DG-PUSCH will result in sending multiple SRs and uplink grants, which is not an efficient use of resources. Therefore, recognizing the shortcomings of DG-PUSCH, Configured Grant PUSCH (CG-PUSCH) was introduced in NR. In CG-PUSCH, the UE is pre-configured with periodic PUSCH resources using Radio Resource Control (RRC) configuration, 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:

[0078] · Type 1CG-PUSCH : Once a CG-PUSCH resource is configured by RRC, the UE can use it without activation; and

[0079] · Type 2CG-PUSCH : CG-PUSCH resources are first configured by RRC. A UE can only use CG-PUSCH resources if it receives an activation DCI which is an UL grant with a configured Scheduling-Radio Network Temporary Identifier (CS-RNTI).

[0080] Once CG-PUSCH is activated, the UE can use it until it is deactivated via another DCI. Type 2 CG-PUSCH provides better control for the gNB scheduler,

[0081] And thus use resources more efficiently.

[0082] CP-OFDM and DFT-S-OFDM

[0083] The coupling loss (CL) between the UE and the gNB depends strongly on the distance between the UE and the gNB, but also on any obstacles that happen to be in the line of sight between the UE and the gNB, such as buildings, traffic, foliage, etc. To a lesser extent, the CL is also affected by propagation conditions such as fading due to precipitation and Doppler spread due to UE mobility. On the 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 if the UE battery can sustain higher power. Therefore, there are limits to improving UL coverage by increasing transmit power.

[0084] Given the CL, it is therefore expected that cell coverage can be improved, especially for UEs located at the cell edge. 3GPP has completed the basic release of 5G in 3GPP Release 15, called New Radio (NR), and further enhancements have been added in 3GPP Releases 16 and 17. In these releases, transmissions in the downlink are based on a cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) waveform, while the uplink can use CP-OFDM or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) waveform.

[0085] The benefit of supporting DFT-S-OFDM in the uplink is that it increases coverage due to its lower peak-to-average power ratio (PAPR) than CP-OFDM, especially when the UE is at the edge of the cell. Lower PAPR allows the UE to transmit with a higher average power, which improves UL coverage. DFT-S-OFDM is a form of transform precoding. DFT-S-OFDM waveforms can be used in single carrier-frequency division multiple access (SC-FDMA) multiple access schemes. Alternatively, the UE can transmit at the same radiated power level in a more efficient manner because the power amplifier in the UE can operate with less back-off. However, the DFT-S-OFDM implemented in 3GPP Release 15 to Release 17 only supports single stream / layer transmission in order to reduce implementation complexity.

[0086] All Release 17 NR capable UEs must support both CP-OFDM and DFT-S-OFDM as UL transmission waveforms. In normal use, in terms of telling the UE which waveform to use in the uplink, the UE receives higher layer "broadcast" signaling (in, for example, System Information Block 1 (SIB1)) to enable or disable DFT-S-OFDM for Msg3 transmissions during the random access procedure. Alternatively, the UE may receive dedicated semi-static (e.g., Radio Resource Control RRC) signaling as part of the PUSCH (Physical Uplink Shared Channel) configuration for UL transmissions. The configuration details for supporting both CP-OFDM and DFT-S-OFDM in the uplink are captured, for example, in Section 6.1.3 of [3].

[0087] As described above, DFT-S-OFDM is similar to a single-carrier waveform and has a lower PAPR than a multi-carrier CP-OFDM waveform. Therefore, a transmitter using DFT-S-OFDM can operate its output power amplifier at its nonlinear characteristic region without worrying about excessive waveform clipping, thereby producing a lower adjacent channel leakage ratio (ACER) and reduced interference at the victim receiver in the adjacent channel. In addition, because of its lower ACER (i.e., the ratio of the power within the allocated frequency channel to the power in the adjacent channel), the UE can operate with a lower maximum power reduction (MPR) factor than a UE transmitting using CP-OFDM. This means that a UE transmitting using DFT-S-OFDM in the UL is allowed to transmit more power (in some cases, up to 1.5dB more power) than a UE using CP-OFDM. Therefore, the use of DFT-S-OFDM allows a given UE to very efficiently achieve the maximum output power for its class while saving battery power. In addition, since DFT-S-OFDM does not support multiple-input multiple-output (MIMO) transmission, there is no cross-spatial interference, which means that for the same UE transmit power, DFT-S-OFDM can provide significantly more coverage than CP-OFDM. 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 they are in good coverage.

[0088] This suggests 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 its coverage needs to be increased because, for example, it is about to leave good coverage; either for all UL transmissions (such as PUSCH), or only for those UL transmissions that are out of coverage.

[0089] The configuration of the UL waveform of Msg3 for the 4-step RACH procedure in Release 17 is done via the msg3-transformPrecoding field of the SIB1 RACH-ConfigCommon information element (IE). Since this is configured in the SIB, it is cell-specific and the same for all UEs, whether in coverage or out of coverage. Therefore, it is technically not feasible to use such a SIB to instruct UEs in poor coverage or UEs out of coverage to switch to DFT-S-OFDM, because UEs that are in good coverage and are unlikely to leave good coverage will also receive such a SIB. Then, performing such signaling to instruct UEs in poor coverage or UEs out of coverage to switch from CP-OFDM to DFT-S-OFDM via SIB would require, for example, the specification of a new, different type of SIB, which would therefore have a fairly significant regulatory impact.

[0090] Semi-static configuration of the UL waveform for dynamic grants is implemented in Release 17 via the transformPrecoding field of the RRC PUSCH-Config IE. Similarly, for configured grants, it is implemented via the transformPrecoding field of the RRCConfiguredGrantConfig IE. Semi-static configuration via RRC means that the UE can be configured to use DFT-S-OFDM indefinitely until it is changed by a new RRC configuration. The network can do this when the network determines that the UE is in a coverage-limited situation or out of coverage (or is about to leave coverage). However, since RRC configuration can be slow, the UE may have gone out of coverage without having a chance to ACK and apply the RRC command.

[0091] Therefore, it is necessary to find a more efficient method to instruct the UE to switch the waveform to DFT-S-OFDM, especially when the UE is in poor coverage, out of coverage, or about to be out of coverage. Therefore, embodiments of the present technology seek to provide a solution for solving such problems.

[0092] NR waveform switching for coverage extension

[0093] Figure 5A partially schematic, partial message flow diagram representation of a wireless communication system including a communication device (e.g., UE) 101 and an infrastructure device (e.g., gNB) 102 according to at least some embodiments of the present technology is shown. The communication device 101 is configured to transmit signals to and / or receive signals from a wireless communication network, for example, to and from the infrastructure device 102. Specifically, the communication device 101 may be configured to transmit data to and / or receive data from the wireless communication network (e.g., to and / or from the infrastructure device 102) via a wireless radio interface provided by the wireless communication network (e.g., a Uu interface between the communication device 101 and a radio access network (RAN) including the infrastructure device 102). The communication device 101 and the infrastructure device 102 each include a transceiver (or transceiver circuit system) 101.1, 102.1 and a controller (or controller circuit system) 101.2, 102.2. Each of the controllers 101.2, 102.2 may be, for example, a microprocessor, a CPU, or a dedicated chipset.

[0094] like Figure 5 As shown in the example, the transceiver circuit 101.1 and the controller circuit system 101.2 of the communication device 101 are configured in combination to: transmit 104 a first uplink signal based on a first waveform type (e.g., CP-OFDM) to a cell of the wireless communication network (e.g., formed by the infrastructure equipment 102), 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) that, based on satisfying a predetermined condition, the communication device 101 is to transmit a second uplink signal based on a second waveform type (e.g., DFT-S-OFDM) instead of the first waveform type, the second waveform type being different from the first waveform type; and transmit 108 a second uplink signal based on the second waveform type to the cell of the wireless communication network (e.g., to the infrastructure equipment 102). Here, the predetermined condition may include (or may indicate) that the communication device 101 moves outside the uplink coverage area of ​​a cell of the wireless communication network, or the predetermined condition may include that the UE is switched (or is about to be switched) to a non-terrestrial network (NTN) where the use of a waveform (such as DFT-S-OFDM) will be advantageous, etc.

[0095] For a UE in RRC idle mode that happens to be outside of normal coverage, such a UE may still be able to reach the network with RACH Msg1 (i.e., of a 4-step RACH process) because of the PRACH power ramp that can be engaged during the RACH process. In other words, the first uplink signal may be the first message (e.g., msg1) of a (4-step) random access RACH process 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 does not receive the RAR, and 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 is increased relative to the previous transmission of the first uplink signal.

[0096] The gNB may be able to determine whether a UE is out of normal coverage using various means. 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 specific preamble used for successful retransmissions by the UE (where such a preamble may indicate or be associated with a power ramp level - for example, 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 gNB retaining a subset of preambles for UEs in poor coverage or out of coverage and another subset for UEs in normal coverage (i.e., preamble segmentation), the gNB may be able to detect whether a UE is out of normal coverage. Another way that the gNB may be able to determine whether a UE is out of normal coverage may be at the RACH opportunities used by the UE to transmit the first signal (i.e., the RACH preamble) - for example, some RACH opportunities may be used for UEs in normal coverage and other ROs may be used for UEs that require coverage extension. In coverage extension, the UE will repeat the preamble. If there is a known starting point (RO) for these repetitions and the gNB detects the preamble only in late ROs, the gNB can know that the UE is in bad coverage.

[0097] If the UE must power ramp the PRACH above a certain level, then according to some embodiments of the present technology, it should be determined that it should use DFT-S-OFDM for Msg3 or msgA PUSCH. In other words, the communication device can be configured to determine that the first uplink signal has not been successfully received by the cell of the wireless communication network to retransmit the first uplink signal one or more times, wherein the transmission power of each retransmission of the first uplink signal is increased relative to the previous transmission of the first uplink signal, and based on the transmission power of one of the retransmissions of the first uplink signal being higher than a specified threshold power, it is determined that based on satisfying a predetermined condition, the communication device is to transmit the second uplink signal based on the second waveform type instead of the first waveform type.

[0098] 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 higher than a threshold. That is, the UE may determine whether or not the UE needs to perform power ramping. The power threshold may be RRC configured (e.g., in SIB or UE-specific signaling) or predefined in the specification.

[0099] In the above two arrangements of embodiments of the present technology, the UE can autonomously decide which waveform to use based on the amount of power ramp and / or whether the preamble transmission power is above a threshold. Because 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 can estimate whether the UE is at the cell edge or out of coverage, and if so, it can first try to decode it using DFT-S-OFDM; and if it fails, it uses CP-OFDM, and vice versa for the case where the gNB knows that the UE is in coverage. In other words, the infrastructure equipment can be configured to determine that the first uplink signal is a first message of a random access RACH procedure (e.g., msgA PRACH for a 2-step RACH procedure or Msg1 for a 4-step RACH procedure) initiated by the communication device with a cell of the wireless communication network, and receive the second signal by blindly decoding the second signal according to each of the first waveform type and the second waveform type.

[0100] As will be appreciated by those skilled in the art, multiple PRACH transmission is a method by which a UE in a cell edge or out of coverage reaches a gNB by transmitting multiple PRACHs to the gNB using the same preamble. The gNB will combine these multiple PRACH transmissions to improve its SNR. Therefore, in another implementation of an embodiment of the present disclosure, the gNB may determine that a UE is out of coverage by determining the number of multiple PRACH transmissions made 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 the SIB or defined in the specification.

[0101] There are implementation specific methods that network providers can use to determine whether a UE is out of coverage. For example, in the prior art in eMTC, the eNB can estimate the location of the UE based on the last known location when the UE was connected, and if the UE is at the cell edge, the eNB can adjust its repetition of paging messages for it under the assumption that the UE is at the cell edge. Of course, as will be known to those skilled in the art, similar and other mechanisms can be used to determine the location of an idle mode UE.

[0102] Alternatively or additionally, if the gNB can determine whether the UE is in coverage, at a cell edge, or out of coverage, for example using a vendor-specific implementation or a standardized method (such as preamble / RACH opportunity segmentation) or based on the number of multiple PRACH transmissions, the gNB can include a new bit (e.g., a reserved bit in the RAR - i.e., an "R" bit is known to those skilled in the art) in a random access response (RAR) to inform the UE that it should use DFT-S-OFDM (4-step RACH) for Msg3, which may be a second uplink signal transmitted by the UE. In other words, according to such an arrangement of an embodiment of the present technology, the indication can be received by the communication device from a 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 can be carried by a reserved bit of the RAR message. The infrastructure equipment can 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.

[0103] In at least some such arrangements of embodiments of the present technology, for 2-step RACH, a gNB that has determined that the UE is at a cell edge or out of coverage engages a DFT-S-OFDM receiver for msgA PUSCH.

[0104] In addition to the UE determining that the second uplink signal will be transmitted based on the second waveform type (e.g., DFT-S-OFDM) instead of the first waveform type based on the satisfaction of a predetermined condition (e.g., the UE is out of coverage or out of good coverage) based on an indication in the RAR or its PRACH ramp power is higher than a threshold power, some UEs arranged 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 the second uplink signal based on the second waveform type, and determine that based on the satisfaction of the predetermined condition, 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.

[0105] For example, for a UE in RRC connected or RRC inactive mode that happens to be outside of (good) UL coverage, in some arrangements, the SIB 1 transformPrecoding field may be overwritten via new RRC or MAC CE signaling. 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 a medium access control MAC control element.

[0106] In some such arrangements of embodiments of the present technology, the rewritten RRC or MAC CE signaling can 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 a (4-step or 2-step) 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 (e.g., msg3 or msgA).

[0107] When the UE is in RRC connected mode, there are other arrangements of embodiments of the present disclosure for RACH processing. For example, the gNB may also include a waveform in the PDCCH command for 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, 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.

[0108] In other arrangements of embodiments of the present technology, the indication may be received by the communication device in a DCI from the infrastructure equipment. For example, for PUSCH, there is a dynamic grant configured for UL data transmission and a configured authorized PUSCH. Since RRC signaling may be quite slow, in terms of dynamic configuration, the command to switch to / from DFT-S-OFDM may be sent in a DCI that schedules the PUSCH or sets or activates the CG. In other words, the DCI may indicate uplink resources to be used by the communication device for transmitting a second uplink signal, or the DCI may be an activation DCI indicating that unauthorized resources for which the communication device is able to transmit signals to a cell of the wireless communication network are activated or deactivated. To do this, it may be necessary to add additional bits to the scheduling / activation DCI. Those skilled in the art should note that this choice may have significant regulatory impacts.

[0109] Those skilled in the art should note that in arrangements of embodiments of the present technology in which the UE can determine that it should switch waveforms based on an indication received from the network, such indications can be received based on the UE being outside good coverage (i.e., it is within DL coverage but not within good UL coverage, for example because it is based on being at the edge of a cell) or based on the UE being completely outside UL coverage. In other words, in response to the communication device moving outside the area of ​​good coverage of a cell of the wireless communication network or in response to the communication device completely moving outside the area of ​​coverage of a cell of the wireless communication network, the indication can be received by the communication device from a cell of the wireless communication network. In some other arrangements of embodiments of the present technology, the indication can 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 a second waveform (e.g., DFT-S-OFDM) without having to wait for additional instructions from the network. In other words, the indication can be received by the communication device from a cell of the wireless communication network before the communication device moves outside the uplink coverage area of ​​the cell of the wireless communication network.

[0110] Figure 6 A flow chart illustrating an example process of communication in a communication system according to an embodiment of the present technology is shown. Figure 6 The process shown is a method of operating a communication device.

[0111] The method starts at step S1. The method includes, 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 instead of the first waveform type based on satisfying a predetermined condition, the second waveform type being different from the first waveform type. Then, in step S4, the process includes transmitting a second uplink signal to the cell of the wireless communication network based on the second waveform type. Here, the predetermined condition may include (or indicate) that the communication device moves outside the uplink coverage area of ​​the cell of the wireless communication network. The process ends at step S5.

[0112] Those skilled in the art will understand that Figure 6 The method shown may be modified according to the implementation of the present technology. For example, other intermediate steps may be included in the method, or the steps may be performed in any logical order. Figure 5 The example communication system shown describes embodiments of the present technology, but 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.

[0113] Those skilled in the art will further appreciate that such infrastructure equipment and / or communication devices as defined herein may be further defined according to the various arrangements and implementations discussed in the preceding paragraphs. Those skilled in the art will also appreciate that such infrastructure equipment and communication devices as defined and described herein may form part of a communication system other than the communication system defined in the present disclosure.

[0114] The following numbered paragraphs provide additional example aspects and features of the present technology:

[0115] Paragraph 1. A method of operating a communication device, the method comprising:

[0116] transmitting a first uplink signal to a cell of a wireless communication network based on a first waveform type,

[0117] 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

[0118] A second uplink signal is transmitted to a cell of the wireless communication network based on the second waveform type.

[0119] Paragraph 2. A method according to paragraph 1, wherein the predetermined condition includes the communication device moving outside the uplink coverage area of ​​a cell of the wireless communication network.

[0120] Paragraph 3. The method according to paragraph 1 or paragraph 2, comprising:

[0121] Based on satisfying a predetermined condition, it is autonomously determined that the communications device is to transmit a second uplink signal based on the second waveform type instead of the first waveform type.

[0122] Paragraph 4. A method according to any one of paragraphs 1 to 3, comprising:

[0123] 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

[0124] Based on satisfying the predetermined condition, based on the received indication, it is determined that the communications device is to transmit a second uplink signal based on the second waveform type instead of the first waveform type.

[0125] Paragraph 5. A method according to paragraph 4, wherein the indication is received by the communication device from a cell of the wireless communication network in downlink control information DCI.

[0126] Paragraph 6. A method according to paragraph 5, wherein the DCI indicates uplink resources to be used by the communication device to transmit the second uplink signal.

[0127] Paragraph 7. A method according to paragraph 5 or paragraph 6, wherein the DCI is an activation DCI indicating that unlicensed resources are activated or deactivated in which the communication device is able to transmit signals to a cell of the wireless communication network in the unlicensed resources.

[0128] Paragraph 8. A method according to any one 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, 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.

[0129] Paragraph 9. A method according to any one of paragraphs 4 to 8, wherein the indication is received by the communication device from a cell of the wireless communication network in semi-static signaling.

[0130] Paragraph 10. A method according to paragraph 9, wherein the semi-static signaling is radio resource control RRC signaling.

[0131] Paragraph 11. A method according to any one 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.

[0132] Paragraph 12. A method according to any one of paragraphs 4 to 11, wherein the indication is carried by a medium access control MAC control element.

[0133] Paragraph 13. A method according to 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 an area of ​​good coverage of the cell of the wireless communication network.

[0134] Paragraph 14. A method according to 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 the coverage area of ​​the cell of the wireless communication network.

[0135] Paragraph 15. A method according to any of paragraphs 4 to 14, 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.

[0136] Paragraph 16. A method according to any one of paragraphs 4 to 15, wherein 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.

[0137] Paragraph 17. The method according to paragraph 16, comprising:

[0138] determining that the first uplink signal has not been successfully received by a cell of the wireless communication network, and

[0139] 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 the transmission power of each retransmission of the first uplink signal is increased relative to a previous transmission of the first uplink signal.

[0140] Paragraph 18. A method according to paragraph 17, wherein the indication is received by the communication device from a cell of the wireless communication network based on a preamble code used by the communication device to retransmit a first uplink signal, the first uplink signal being successfully received by the cell of the wireless communication network, the preamble code being from a set of one or more preamble codes associated with a transmission power greater than a specified threshold power.

[0141] Paragraph 19. A method according to any one of paragraphs 16 to 18, comprising:

[0142] determining that the first uplink signal has not been successfully received by a cell of the wireless communication network, and

[0143] 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 timing for each retransmission of the first uplink signal is changed relative to a previous transmission of the first uplink signal,

[0144] The indication is received by the communication device from a cell of the wireless communication network based on a RACH opportunity used by the communication device to retransmit a first uplink signal, and the first uplink signal is successfully received by the cell of the wireless communication network.

[0145] Paragraph 20. The method according to any one of paragraphs 16 to 19, comprising:

[0146] determining that the first uplink signal has not been successfully received by a cell of the wireless communication network, and

[0147] 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,

[0148] 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 higher than a specified threshold.

[0149] Paragraph 21. A method according to any one of paragraphs 16 to 20, wherein the indication is received by the communication device from a cell of the wireless communication network in a random access response RAR message in response to the first message of the RACH process, wherein the indication is carried by a reserved bit of the RAR message.

[0150] Paragraph 22. The method according to any one of paragraphs 16 to 21, comprising:

[0151] retransmitting the first uplink signal one or more times according to the multi-PRACH transmission mode,

[0152] The indication is received by the communication device from a cell of the wireless communication network based on the number of retransmissions used in the multiple PRACH transmissions for the first message of the RACH process being higher than a specified threshold.

[0153] Paragraph 23. A method according to any one of paragraphs 4 to 22, 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.

[0154] Paragraph 24. 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 a RACH opportunity in a predetermined RACH opportunity set.

[0155] Paragraph 25. 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 initiated by the communication device with a cell of the wireless communication network, and wherein the method comprises:

[0156] determining that the first uplink signal has not been successfully received by a cell of the wireless communication network,

[0157] 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

[0158] Based on the transmission power of one of the retransmissions of the first uplink signal being higher than a specified threshold power, 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.

[0159] Paragraph 26. 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 initiated by the communication device with a cell of the wireless communication network, and wherein the method comprises:

[0160] Based on a 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 a second uplink signal based on the second waveform type instead of the first waveform type.

[0161] Paragraph 27. A method according to any of paragraphs 1 to 26, wherein the second waveform type is discrete Fourier transform spread orthogonal frequency division multiplexing DFT-S-OFDM.

[0162] Paragraph 28. A communication device comprising:

[0163] transceiver circuitry, and

[0164] Controller circuitry configured in combination with transceiver circuitry

[0165] transmitting a first uplink signal to a cell of a wireless communication network based on a first waveform type,

[0166] 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

[0167] A second uplink signal is transmitted to a cell of the wireless communication network based on the second waveform type.

[0168] Paragraph 29. A circuit system for a communication device, comprising:

[0169] transceiver circuitry, and

[0170] Controller circuitry configured in combination with transceiver circuitry

[0171] transmitting a first uplink signal to a cell of a wireless communication network based on a first waveform type,

[0172] 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

[0173] A second uplink signal is transmitted to a cell of the wireless communication network based on the second waveform type.

[0174] Paragraph 30. A method of operating infrastructure equipment forming part of a first wireless communication network, the method comprising:

[0175] receiving a first uplink signal from a communication device based on a first waveform type,

[0176] 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

[0177] A second uplink signal is received from the communication device based on the second waveform type.

[0178] Paragraph 31. A method according to paragraph 30, wherein the predetermined condition includes the communication device moving outside an uplink coverage area of ​​a cell of the wireless communication network formed by the infrastructure equipment.

[0179] Paragraph 32. A method as described in 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 a second waveform type.

[0180] Paragraph 33. A method according to paragraph 32, wherein the indication is transmitted by the infrastructure equipment to the communication device in downlink control information DCI.

[0181] Paragraph 34. A method according to paragraph 33, wherein the DCI indicates uplink resources to be used by the communication device to transmit the second uplink signal.

[0182] Paragraph 35. A method according to paragraph 33 or paragraph 34, wherein the DCI is an activation DCI indicating that unlicensed resources in which the communication device can transmit signals to the infrastructure equipment in the unlicensed resources are activated or deactivated.

[0183] Paragraph 36. A method according to any one of paragraphs 32 to 35, 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.

[0184] Paragraph 37. A method according to any of paragraphs 32 to 36, wherein the indication is transmitted by the infrastructure equipment to the communication device in semi-static signaling.

[0185] Paragraph 38. A method according to paragraph 37, wherein the semi-static signaling is radio resource control RRC signaling.

[0186] Paragraph 39. A method according to any one 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.

[0187] Paragraph 40. A method according to any of paragraphs 32 to 39, wherein the indication is carried by a medium access control (MAC) control element.

[0188] Paragraph 41. A method as described in 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.

[0189] Paragraph 42. A method as described in 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 an area of ​​good coverage of the infrastructure equipment.

[0190] Paragraph 43. A method according to any of paragraphs 32 to 42, 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.

[0191] Paragraph 44. A method according to any of paragraphs 32 to 43, wherein the first uplink signal is a first message of a random access RACH procedure initiated by the communication device with the infrastructure equipment.

[0192] Paragraph 45. The method according to paragraph 44, comprising:

[0193] A first uplink signal is received from a communication device as a successfully received retransmission among 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.

[0194] Paragraph 46. A method according to paragraph 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 a successfully received retransmission, the preamble code being from a set of one or more preamble codes associated with a transmission power above a specified threshold power.

[0195] Paragraph 47. A method according to any one of paragraphs 44 to 46, comprising

[0196] receiving, from the communication device, a 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,

[0197] Therein, the indication is transmitted by the infrastructure equipment to the communication device based on a RACH opportunity used by the communication device for a transmission successfully received.

[0198] Paragraph 48. A method according to any one of paragraphs 44 to 47, comprising

[0199] receiving a first uplink signal from the communication device as a successfully received retransmission among one or more retransmissions of the first uplink signal,

[0200] Therein, the indication is transmitted by the infrastructure equipment to the communication device based on a determination by the infrastructure equipment that a number of retransmissions that have been performed by the communication device prior to the successfully received retransmission is above a specified threshold.

[0201] Paragraph 49. 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.

[0202] Paragraph 50. A method according to 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 the first uplink signal in a RACH opportunity from a predetermined set of RACH opportunities.

[0203] Paragraph 51. A method according to any one of paragraphs 32 to 50, comprising

[0204] determining that the 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,

[0205] Wherein, based on the number of retransmissions used in the multiple PRACH transmissions of the first message for the RACH procedure being higher than a specified threshold, the indication is transmitted by the infrastructure equipment to the communication device.

[0206] Paragraph 52. A method according to any one of paragraphs 32 to 51, 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 process, wherein the indication can be carried by a reserved bit of the RAR message.

[0207] Paragraph 53. A method according to any one of paragraphs 30 to 52, comprising

[0208] It is determined 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.

[0209] The second signal is received by blindly decoding the second signal according to each of the first waveform type and the second waveform type.

[0210] Paragraph 54. A method as described in any of paragraphs 30 to 53, wherein the second waveform type is discrete Fourier transform spread orthogonal frequency division multiplexing DFT-S-OFDM.

[0211] Paragraph 55. An infrastructure device forming part of a first wireless communication network, the infrastructure device comprising:

[0212] transceiver circuitry, and

[0213] Controller circuitry configured in combination with transceiver circuitry

[0214] receiving a first uplink signal from a communication device based on a first waveform type,

[0215] 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

[0216] A second uplink signal is received from the communication device based on a second waveform type.

[0217] Paragraph 56. A circuit system of infrastructure equipment forming part of a first wireless communication network, the infrastructure equipment comprising

[0218] transceiver circuitry, and

[0219] Controller circuitry configured in combination with transceiver circuitry

[0220] receiving a first uplink signal from a communication device based on a first waveform type,

[0221] 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

[0222] A second uplink signal is received from the communication device based on a second waveform type.

[0223] Paragraph 57. A wireless communication system comprising a communication device according to paragraph 28 and an infrastructure device according to paragraph 55.

[0224] Paragraph 58. A computer program comprising instructions which, when loaded onto a computer, cause the computer to perform a method according to any one of paragraphs 1 to 27 or paragraphs 30 to 54.

[0225] Paragraph 59. A non-transitory computer-readable storage medium storing a computer program according to Paragraph 58.

[0226] It will be appreciated that for clarity, the above description has described embodiments with reference to different functional units, circuit systems and / or processors. However, it will be apparent that any suitable distribution of functionality between different functional units, circuit systems and / or processors may be used without departing from the embodiments.

[0227] The described embodiments can be implemented in any suitable form, including hardware, software, firmware or any combination of these. The described embodiments can be optionally implemented at least in part as computer software running on one or more data processors and / or digital signal processors. The elements and components of any embodiment can be implemented physically, functionally and logically in any suitable manner. In fact, the function can be implemented in a single unit, in multiple units or as part of other functional units. Therefore, the disclosed embodiments can be implemented in a single unit, or can be physically and functionally distributed between different units, circuit systems and / or processors.

[0228] Although the present disclosure has been described in conjunction with some embodiments, the present disclosure is not intended to be limited to the specific form set forth herein. In addition, although features may appear to be described in conjunction with specific embodiments, those skilled in the art will recognize that the various features of the described embodiments may be combined in any manner suitable for implementing the present technology.

[0229] References

[0230] [1]Holma H.and Toskala A,“LTE for UMTS OFDMA and SC-FDMA based radioaccess”,John Wiley and Sons,2009.

[0231] [2]TR 38.913,“3rd Generation Partnership Project;TechnicalSpecification Group Radio Access Network;Study on Scenarios and Requirementsfor Next Generation Access Technologies(Release 14)”,3GPP,vl4.3.0,August2017.

[0232] [3]TS 38.214,“3rd Generation Partnership Project;TechnicalSpecification Group Radio Access Network;NR;Physical layer procedures fordata(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 includes 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 according to claim 4, wherein: The indication is received by the communication device in downlink control information, DCI, from the cell of the wireless communication network.

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

10. The method according to claim 9, wherein: The semi-static signaling is radio resource control RRC signaling.

11. The method according to 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 according to claim 4, wherein: The indication is carried by a medium access control MAC control element.

13. The method according to 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 according to 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 outside of an area of ​​coverage of the cell of the wireless communication network.

15. The method according to 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 to 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. The 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 used by the communication device for retransmitting the first uplink signal, the first uplink signal being successfully received by the cell of the wireless communication network, the preamble being from a set of one or more preambles associated with a transmission power above a specified threshold power.

19. 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 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 is higher than a specified threshold.

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

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

25. The method of 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 of 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 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.

29. A circuit system for a communication device, comprising: transceiver circuitry, and A controller circuit system configured in combination with the transceiver circuit system 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.

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, 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 received from the communication device based on the second waveform type.

31. The method according to claim 30, wherein: The predetermined condition includes 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 in the unlicensed resources, 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 the 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 of 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 a previous transmission of the first uplink signal.

46. ​​The method of claim 45, wherein: The indication is transmitted by the infrastructure equipment to the communication device based on a preamble used by the communication device for the successfully received retransmission, the preamble being from a set of one or more preambles 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 communication device based on the communication 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 communication device based on the communication 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 A controller circuit system configured in combination with the transceiver circuit system 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 The second uplink signal is received from the communication device based on the second waveform type.

56. A circuit system of infrastructure equipment forming part of a first wireless communication network, the infrastructure equipment comprising: transceiver circuitry, and A controller circuit system configured in combination with the transceiver circuit system 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 The second uplink signal is received from the communication device based on the second waveform type.

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.

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