METHOD, APPARATUS AND COMPUTER PROGRAM FOR USE IN POWER HEADROOM

REPORTING

Field

The present application relates to a method, apparatus, and computer program and in particular but not exclusively to a method, apparatus and computer program for use in power headroom reporting (PHR).

Background

A communication system can be seen as a facility that enables communication between two or more devices such as user terminals, machine-like terminals, base stations and/or other nodes by providing communication channels for carrying information between the communicating devices. A communication system can be provided for example by means of a communication network and one or more compatible communication devices. The communication may comprise, for example, communication of data for carrying data for voice, electronic mail (email), text message, multimedia and/or content data communications and so on. Non-limiting examples of services provided include two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

In a wireless system at least a part of communications occurs over wireless interfaces. Examples of wireless systems include public land mobile networks (PLMN), satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). A local area wireless networking technology allowing devices to connect to a data network is known by the tradename Wi-Fi (or Wi-Fi). Wi-Fi is often used synonymously with WLAN. The wireless systems can be divided into cells, and are therefore often referred to as cellular systems. A base station provides at least one cell.

A user can access a communication system by means of an appropriate communication device or terminal capable of communicating with a base station. Hence nodes like base stations are often referred to as access points. A communication device of a user is often referred to as user equipment (UE) or user apparatus. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling communications with the base station and/or communications directly with other user devices. The communication device can communicate on appropriate channels, e.g. listen to a channel on which a station, for example a base station of a cell, transmits. A communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and/or parameters which shall be used for the connection are also typically defined. Non-limiting examples of standardised radio access technologies include GSM (Global System for Mobile), EDGE (Enhanced Data for GSM Evolution) Radio Access Networks (GERAN), Universal Terrestrial Radio Access Networks (UTRAN) and evolved UTRAN (E-UTRAN). An example communication system architecture is the long-term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio-access technology. The LTE is standardized by the 3rd Generation Partnership Project (3GPP). The LTE employs the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access and a further development thereof which is sometimes referred to as LTE Advanced (LTE-A). Since introduction of fourth generation (4G) services increasing interest has been paid to the next, or fifth generation (5G) standard.

In the LTE system, PHR provides the serving eNodeB (eNB) with information about the difference between the nominal UE maximum transmit power and the estimated transmission power for example PUSCH (physical uplink shared control channel) and/or PUCCH (physical uplink control channel) transmission. The eNB can use the PHR information for its uplink power control and uplink scheduling. It may be desirable to have PHR reporting for 5G or similar systems.

Summary

According to an aspect, there is provided a method comprising: determining, in a communications device, information relating to channel quality associated with communications between said communications device and an access point, said communication device being arranged to use a plurality of different waveforms for communicating with said access point; and using at least one of a plurality of different power head room report modes, wherein at least one of said power head room report modes is associated with one of said plurality of different waveforms, said used at least one power head room report mode based on the information relating to channel quality.

The determining information relating to channel quality may comprise measuring at least one reference signal.

The determining in a communications device information relating to channel quality may comprise determining one or more of RSRP, RSRQ, CQI and path loss.

The plurality of different power head room report modes may comprise at least one of: a discrete Fourier transform-spread-orthogonal frequency division multiplexing mode; a cyclic prefix orthogonal frequency division multiplexing mode; a mode using both discrete Fourier transform-spread-orthogonal frequency division multiplexing and cyclic prefix orthogonal frequency division multiplexing; and a mode using a long term evolution discrete Fourier transform-spread-orthogonal frequency division multiplexing mode.

The method may comprise causing information about the channel quality to be transmitted to the access node and receiving, in response to said channel quality information, information about which of said plurality of different power head room reporting modes is to be used.

The information about which of said plurality of different power head room reporting modes is used may be provided for different carrier and/or beams.

The method may comprise determining, in said communications device, which of said plurality of different power head room report modes is to be used, using said channel quality information.

The used at least one of said plurality of different power head room modes may be dependent on said channel quality information with respect to at least one threshold.

At two thresholds may be used.

At least one different threshold may be provided for different carriers and/or different beams.

The method may comprise receiving said at least one threshold at said communications device, and determining in said communications device using said channel quality information which of said plurality of different power head room report modes is to be used comprises comparing said channel quality information with said at least one received threshold

The method may comprise using a trigger to determine when to send a power headroom report, wherein two of the modes are associated with different triggers.

The trigger may comprises one or more of: a defined path loss; a periodic timer; a prohibiting of power headroom report mode timer; activation of cell; deactivation of a cell; configuration or reconfiguration of a power headroom report mode functionality.

When both a first and second power headroom reporting mode are used, one of said modes may be only used for a primary cell and the other of the modes is used for both the primary cell and a secondary cell.

When one of said power report modes is triggered, the method may comprise causing reporting using said triggered one of said power head room report modes and at least one other of said power head room report mode

The method may be performed in an apparatus. The apparatus may be provided in a communications device.

According to another aspect, there is provided an apparatus in a communications device comprising: means for determining information relating to channel quality associated with communications between said communications device and an access point, said communication device being arranged to use a plurality of different waveforms for communicating with said access point; and means for causing at least one of a plurality of different power head room report modes to be used, wherein at least one of said power head room report modes is associated with one of said plurality of different waveforms, said used at least one power head room report mode based on the information relating to channel quality

The means for determining may be for measuring at least one reference signal. The means for determining may be for determining one or more of RSRP, RSRQ, CQI and path loss.

The plurality of different power head room report modes may comprise at least one of: a discrete Fourier transform-spread-orthogonal frequency division multiplexing mode; a cyclic prefix orthogonal frequency division multiplexing mode; a mode using both discrete Fourier transform-spread-orthogonal frequency division multiplexing and cyclic prefix orthogonal frequency division multiplexing; and a mode using a long term evolution discrete Fourier transform-spread-orthogonal frequency division multiplexing mode

The apparatus may comprise means for causing information about the channel quality to be transmitted to the access node and means for receiving, in response to said channel quality information, information about which of said plurality of different power head room reporting modes is to be used.

The information about which of said plurality of different power head room reporting modes is used may be provided for different carrier and/or beams.

The apparatus may comprise means for determining which of said plurality of different power head room report modes is to be used, using said channel quality information.

The used at least one of said plurality of different power head room modes may be dependent on said channel quality information with respect to at least one threshold.

At two thresholds may be used.

At least one different threshold may be provided for different carriers and/or different beams.

The apparatus may comprise means for receiving said at least one threshold, and means for determining using said channel quality information which of said plurality of different power head room report modes is to be used is for comparing said channel quality information with said at least one received threshold

The apparatus may comprise means for using a trigger to determine when to send a power headroom report, wherein two of the modes are associated with different triggers.

The trigger may comprises one or more of: a defined path loss; a periodic timer; a prohibiting of power headroom report mode timer; activation of cell; deactivation of a cell; configuration or reconfiguration of a power headroom report mode functionality. When both a first and second power headroom reporting mode are used, one of said modes may be only used for a primary cell and the other of the modes is used for both the primary cell and a secondary cell.

When one of said power report modes is triggered, the apparatus may comprise means for causing reporting using said triggered one of said power head room report modes and at least one other of said power head room report mode

The apparatus may be provided in a communications device.

According to another aspect, there is provided an apparatus for use in a communications device, said apparatus comprising at least one processor and at least one memory including computer code for one or more programs, the at least one memory and the computer code configured, with the at least one processor, to cause the apparatus at least to: determine information relating to channel quality associated with communications between said communications device and an access point, said communication device being arranged to use a plurality of different waveforms for communicating with said access point; and use at least one of a plurality of different power head room report modes, wherein at least one of said power head room report modes is associated with one of said plurality of different waveforms, said used at least one power head room report mode based on the information relating to channel quality.

The at least one memory and the computer code may be configured, with the at least one processor, to cause measuring of at least one reference signal to determine channel quality.

The at least one memory and the computer code may be configured, with the at least one processor, to cause determining one or more of RSRP, RSRQ, CQI and path loss to determine channel quality.

The plurality of different power head room report modes may comprise at least one of: a discrete Fourier transform-spread-orthogonal frequency division multiplexing mode; a cyclic prefix orthogonal frequency division multiplexing mode; a mode using both discrete Fourier transform-spread-orthogonal frequency division multiplexing and cyclic prefix orthogonal frequency division multiplexing; and a mode using a long term evolution discrete Fourier transform-spread-orthogonal frequency division multiplexing mode.

The at least one memory and the computer code may be configured, with the at least one processor, to cause information about the channel quality to be transmitted to the access node and receive, in response to said channel quality information, information about which of said plurality of different power head room reporting modes is to be used.

The information about which of said plurality of different power head room reporting modes is used may be provided for different carrier and/or beams. The at least one memory and the computer code may be configured, with the at least one processor, to cause determining which of said plurality of different power head room report modes is to be used, using said channel quality information.

The used at least one of said plurality of different power head room modes may be dependent on said channel quality information with respect to at least one threshold.

At two thresholds may be used.

At least one different threshold may be provided for different carriers and/or different beams.

The at least one memory and the computer code may be configured, with the at least one processor, to cause receiving said at least one threshold, and comparing said channel quality information with said at least one received threshold to which of said plurality of different power head room report modes is to be used.

The at least one memory and the computer code may be configured, with the at least one processor, to cause using a trigger to determine when to send a power headroom report, wherein two of the modes are associated with different triggers.

The trigger may comprises one or more of: a defined path loss; a periodic timer; a prohibiting of power headroom report mode timer; activation of cell; deactivation of a cell; configuration or reconfiguration of a power headroom report mode functionality.

When both a first and second power headroom reporting mode are used, one of said modes may be only used for a primary cell and the other of the modes is used for both the primary cell and a secondary cell.

When one of said power report modes is triggered, The at least one memory and the computer code may be configured, with the at least one processor, to cause reporting using said triggered one of said power head room report modes and at least one other of said power head room report mode.

According to an aspect, there is provided a method comprising: receiving at an access device from a communications device, information relating to channel quality associated with communications between said communications device and the access point, said communication device being arranged to use a plurality of different waveforms for communicating with said access point; and in response providing information about which of one or more of a plurality of different power head room reporting modes is to be used based on the information relating to channel quality, wherein at least one of said power head room report modes is associated with one of said plurality of different waveforms.

The information relating to channel quality may comprise one or more of RSRP, RSRQ,

CQI and path loss. The plurality of different power head room report modes may comprise at least one of: a discrete Fourier transform-spread-orthogonal frequency division multiplexing mode; a cyclic prefix orthogonal frequency division multiplexing mode; a mode using both discrete Fourier transform-spread-orthogonal frequency division multiplexing and cyclic prefix orthogonal frequency division multiplexing; and a mode using a long term evolution discrete Fourier transform-spread-orthogonal frequency division multiplexing mode

The information about which of said plurality of different power head room reporting modes is to be used may be provided for different carrier and/or beams.

The at least one of said plurality of different power head room modes to be used may be dependent on said channel quality information with respect to at least one threshold.

At two thresholds may be used.

At least one different threshold may be provided for different carriers and/or different beams.

According to an aspect, there is provided an apparatus in an access point, the apparatus comprising: means for receiving from a communications device, information relating to channel quality associated with communications between said communications device and the access point, said communication device being arranged to use a plurality of different waveforms for communicating with said access point; and means for providing, in response, information about which of one or more of a plurality of different power head room reporting modes is to be used based on the information relating to channel quality, wherein at least one of said power head room report modes is associated with one of said plurality of different waveforms.

The information relating to channel quality may comprise one or more of RSRP, RSRQ, CQI and path loss.

The plurality of different power head room report modes may comprise at least one of: a discrete Fourier transform-spread-orthogonal frequency division multiplexing mode; a cyclic prefix orthogonal frequency division multiplexing mode; a mode using both discrete Fourier transform-spread-orthogonal frequency division multiplexing and cyclic prefix orthogonal frequency division multiplexing; and a mode using a long term evolution discrete Fourier transform-spread-orthogonal frequency division multiplexing mode

The information about which of said plurality of different power head room reporting modes is to be used may be provided for different carrier and/or beams.

The at least one of said plurality of different power head room modes to be used may be dependent on said channel quality information with respect to at least one threshold.

At two thresholds may be used.

At least one different threshold may be provided for different carriers and/or different beams. According to another aspect, there is provided an apparatus for use in an access point, said apparatus comprising at least one processor and at least one memory including computer code for one or more programs, the at least one memory and the computer code configured, with the at least one processor, to cause the apparatus at least to: receive from a communications device, information relating to channel quality associated with communications between said communications device and the access point, said communication device being arranged to use a plurality of different waveforms for communicating with said access point; and in response provide information about which of one or more of a plurality of different power head room reporting modes is to be used based on the information relating to channel quality, wherein at least one of said power head room report modes is associated with one of said plurality of different waveforms.

The information relating to channel quality may comprise one or more of RSRP, RSRQ, CQI and path loss.

The plurality of different power head room report modes may comprise at least one of: a discrete Fourier transform-spread-orthogonal frequency division multiplexing mode; a cyclic prefix orthogonal frequency division multiplexing mode; a mode using both discrete Fourier transform-spread-orthogonal frequency division multiplexing and cyclic prefix orthogonal frequency division multiplexing; and a mode using a long term evolution discrete Fourier transform-spread-orthogonal frequency division multiplexing mode

The information about which of said plurality of different power head room reporting modes is to be used may be provided for different carrier and/or beams.

The at least one of said plurality of different power head room modes to be used may be dependent on said channel quality information with respect to at least one threshold.

At two thresholds may be used.

At least one different threshold may be provided for different carriers and/or different beams.

A computer program comprising program code means adapted to perform the herein described methods may also be provided. In accordance with further embodiments apparatus and/or computer program product that can be embodied on a computer readable medium for providing at least one of the above methods is provided.

It should be appreciated that any feature of any aspect may be combined with any other feature of any other aspect.

Brief description of Figures

Some embodiments will now be described in further detail, by way of example only, with reference to the following examples and accompanying drawings, in which: Figure 1 shows a schematic example of a wireless communication system where the invention may be implemented;

Figure 2 shows an example of a communication device;

Figure 3 shows an example of control apparatus;

Figure 4 shows three scenarios for both waveform specific PHR reporting;

Figure 5 shows a scenario for one or two waveform specific PHR reporting based on RSRP (reference signal received power) in some embodiments;

Figure 6 a, b and c show a MAC elements for PHR reporting;

Figure 7 shows a first method flow of some embodiments;

Figure 8 shows a second method flow of some embodiments; and

Figure 9 shows a third method flow of some embodiments.

Detailed description

In general, the following disclosure relates to providing power headroom reporting in a 5G or similar system.

In the following certain exemplifying embodiments are explained with reference to a wireless communication system serving communication devices adapted for wireless communication. Certain general principles of wireless systems are first briefly explained with reference to Figures 1 to 3.

A communication device 20, 21 can be used for accessing various services and/or applications provided via cells 4, 5, 6 of a cellular system. In a wireless communication system the access can be provided via wireless access interfaces between wireless communication devices and one or more base stations of a radio access network 1 . Each communication device and base station may have one or more radio channels open at the same time and may receive signals from more than one source.

The communication devices can move from a cell to another, as illustrated by arrows on top of the devices 20 and 21 in Figure 1 . The process of handling the moving from a cell to the other is called handover. Handovers can be provided, for example, in wireless environment comprising one or more fifth generation (5G) radio access networks (RAN). A part of handover procedure is known as cell reselection.

A base station site can provide at least one cell. In the highly schematic Figure 1 example, a base station site 10 comprising a controller 13 and base station apparatus 12 and 14 is shown to provide a plurality of cells 4 and 5, respectively. A further base station 1 1 may provide further cells 6. The base stations may communicate via the X2 ^* interface, indicated by the dashed line. In Figure 1 , cell 4 is provided by antenna apparatus of station 12 in one location, and at least one further cell is provided by a remote radio head 14. It is noted that this exemplifying arrangement is only shown for illustrative purposes, and that e.g. antenna apparatus 12 can provide more than one cell. The relevance in view of certain examples described below is that the controller 13 of the base station site 10 can control access and devices accessing the radio access network 1 in a number of cells.

A wireless system is typically divided between a radio access system 1 , typically called radio access network (RAN) and a core network (CN) 2. The division is denoted by line 3. The core network can comprise elements such as mobile management entity (MME) 18, home subscriber server (HSS) 19 and so forth. Connection between base station sites of the radio access network (RAN) and core network (CN) element can be provided via appropriate interfaces 15, 16.

A communication device can access a communication system based on various access techniques, for example those based on the third Generation Partnership Project (3GPP) specifications. A non-limiting example of mobile architectures is known as the Evolved Universal Terrestrial Radio Access Network (E-UTRAN). The architecture may of course alternatively comprise a future equivalent to E-UTRAN, for example the architecture of the "Next Gen" or 5G network. A non-limiting example of a base station of a cellular system is what is termed as a NodeB or E-UTRAN NodeB (eNB / ENodeB) in the vocabulary of the 3GPP specifications. The eNBs may provide E-UTRAN features such as user plane Radio Link Control/Medium Access Control/Physical Layer Protocol (RLC/MAC/PHY) and control plane Radio Resource Control (RRC) protocol terminations towards mobile communication devices. At least some of the stations may be arranged to operate on the unlicensed radio spectrum.

Figure 2 shows a schematic, partially sectioned view of a communication device 20 that a user can use for communications. Such a communication device is often referred to as user equipment (UE) or terminal. An appropriate communication device may be provided by any device capable of sending and receiving radio signals. Non-limiting examples include a mobile station (MS) such as a mobile phone or what is known as a 'smart phone', a portable computer provided with a wireless interface card or other wireless interface facility, personal data assistant (PDA) provided with wireless communication capabilities, or any combinations of these or the like. A mobile communication device may provide, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia, positioning data, other data, and so on. Users may thus be offered and provided numerous services via their communication devices. Non-limiting examples of these services include two-way or multi-way calls, data communication or multimedia services or simply an access to a data communications network system, such as the Internet.

A mobile device is typically provided with at least one data processing entity 23, at least one memory 24 and other possible components 29 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with base stations and/or other user terminals. The tasks can include operation related to mobility management such as handling handovers and cell reselections. Further, the tasks can also relate to security aspects of the communications. The data processing, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This apparatus is denoted by reference 26.

A user may control the operation of the device 20 by means of a suitable user interface such as key pad, voice commands, touch sensitive screen or pad, combinations thereof or the like. A display 25, a speaker and a microphone are also typically provided. Furthermore, a mobile communication device may comprise appropriate connectors (either wired or wireless) to other devices and/or for connecting external accessories, for example hands-free equipment, thereto.

The device 20 may receive and transmit signals 28 via appropriate apparatus for receiving and transmitting signals. In Figure 2 transceiver apparatus is designated schematically by block 27. The transceiver may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device. A wireless communication device can be provided with a Multiple Input / Multiple Output (MIMO) antenna system.

Figure 3 shows an example of a control apparatus 30 for a station, for example to be coupled to and/or for controlling one of the stations 1 1 , 12 and 14 of Figure 1 . The control apparatus 30 can be arranged to provide control on configurations used by the communications devices accessing the station, information processing and/or communication operations. A control apparatus can be configured to provide control functions in association with generation, communications, and interpretation of control information. The control apparatus 30 comprises at least one memory 31 , at least one data processing unit 32, 33 and an input/output interface 34. Via the interface the control apparatus can be coupled to the relevant node. The control apparatus 30 can be configured to execute an appropriate software code to provide the control functions.

Some embodiments relate to 5G wireless systems with support for waveforms, such as DFT-s-OFDM (Discrete Fourier Transform-spread-Orthogonal Frequency Division Multiplexing) and CP-OFDM (Cyclic Prefix Orthogonal Frequency Division Multiplexing). It has been proposed in 5G that a plurality of different waveforms be available for use. For example the waveforms may be CP-OFDM or DFT-S-OFDM Some embodiments provide power headroom (PHR) reporting used to support flexible usage of both waveforms at the user equipment (UE). In some embodiments, the signalling overhead may be kept at a low level. It has been proposed for 5G that that two waveforms, i.e. DFT-s-OFDM and CP-

OFDM, may be supported for eMBB (enhanced mobile broadband) uplink for up to 40GHz. The DFT-S-OFDM based waveform may be limited to single stream transmission and targeted at link budget limited cases. A common framework may be provided for CP-OFDM and DFT- S-OFDM based waveforms. NR (new radio) may support DFT-S-OFDM based waveform complementary to CP-OFDM waveform, at least for eMBB uplink for up to 40GHz.

In a LTE system, PHR provides t e serving eNodeB (eNB) with information about the difference between the nominal UE maximum transmit power and the estimated transmission power for PUSCH and/or PUCCH transmission. The eNB can use the PHR information for its uplink power control and uplink scheduling. There are three different types of PHR:

PHR; extended PHR; and dual connectivity PHR.

PHR can be used in single carrier system. Extended PHR is used in a carrier aggregation system where both type 1 for each carrier and type 2 PHR for the primary cell (PCell) are used. The dual connectivity PHR can be used in a dual connectivity scenario, whereby both type 1 and type 2 PHR are also reported for the primary secondary cell (PSCell).

For type 1 PHR, only PUSCH transmission power is considered in the PHR computation formula. For type 2 PHR, both PUSCH and PUCCH transmission power are considered in the PHR computation formula. The computation formula for type 1 and 2 PHR are specified in the 3GPP document TS36.213 which is hereby incorporated by reference. Type 1 PHR

If the UE transmits PUSCH with PUCCH in subframe ^z for serving cell ^c , power headroom for a Type 1 report is computed using

«?typel,c (0 = ?CMAX ,c (* { 10 log ₁₀ ( p _{USC¾ c} (;)) + P ₀ PUSCH, c U) + »cU) ' L _C + & _T F,c (i) + f _c (i) }

" [dB] where, ^m PUSCH, _AND f _c (i _{are defined in sub C} | _ause

P (i)

5.1.1.1. of TS36.213 ^CMAJ fc i _S computed based on the requirements assuming a PUSCH only transmission in subframe ^z . For this case, the physical layer delivers ^PcMA instead of ^PcMAX to higher layers.

Type 2 PHR

If the UE transmits PUSCH simultaneous with PUCCH in subframe ^z for the primary cell, power headroom for a Type 2 report is computed using

™type2 (0 = "PCMAX ,c(

where, ^cMAXc , ^M PUSCH, _C ( _ PUSCH, _C U) _ a _c (j) _ ^Δχ _Ρ ,,( _AND / _C ( _{are the} primary cell parameters as defined in sub clause 5.1.1.1 of TS36.213 and °-™«ΙΗ PL _C h(n _CQI ,n _HARQ ,n _SR ) ^ A _{F PUCCH} (F) ^ A _TxD (F') _md g( ) ^ _defined |η _{sub c} |g _{use 5 1 2} .1 Of

TS36.213. Type 1 PHR is defined per carrier, and type 2 PHR is just defined for PCell and gives more power information for both PUCCH and PUSCH simultaneous transmission.

PHR can either be periodic or event triggered. The PHR procedure may be controlled by a periodic PHR-timer, a prohibit PHR-timer and downlink (dl)-path loss change parameter.

PHR reporting may be event triggered in one or more of the following cases:

1. The periodic PHR-Timer expires;

2. The prohibit PHR-Timer expires or has expired and the path loss has changed more than dl-path loss change dB for at least one activated serving cell of any MAC entity which is used as a path loss reference since the last transmission of a PHR in that MAC entity when that MAC entity has uplink (UL) resources for a new transmission;

3. Upon configuration or reconfiguration of the PHR functionality, which is not used to disable the function;

4. Activation of a secondary cell (SCell) of any MAC entity with a configured uplink; and

5. Addition of the PSCell.

It may be advantageous to provide an enhanced PHR reporting scheme with a low reporting signalling overhead to support flexible transmission with different waveforms. This may be for use with a 5G or similar system.

Some embodiments relate to mobile communication networks with beamforming techniques. For example, 5G radio access technology have proposed using beam forming techniques. Power control may be provided on a beam specific basis. PHR is used in the power control process. It should be appreciated that other embodiments may be used with any other communication system which uses beamforming. For example some wireless area networks may use beamforming. The 5G radio system may use frequencies from 400MHz to 100GHz. Beamforming is considered to be desirable in enabling the use of the higher frequency bands due to coverage issues.

Some transceivers (e.g. a hybrid transceiver architecture) may use analogue beamforming, which may mean a limited number of concurrent beams as this is dependent on the number of antenna ports. It should be appreciated that other embodiments may be used with digital beamforming transceiver architecture or so-called hybrid transceiver architecture which use a hybrid of digital baseband processing (such as MIMO Multiple Input Multiple Output, and /or digital precoding) and analogue beamforming. It should be appreciated that embodiments can be used with any method of beam forming.

Figure 4 shows some embodiments where both waveform specific PHR may be used in order to increase scheduling flexibility. As mentioned previously, it has been proposed in 5G that a plurality of different waveforms be available for use. For example the waveforms may be CP-OFDM or DFT-S-OFDM waveforms. Waveform specific PHR can serve as power information which can be used to assist the network to decide which one or two of CP-OFDM or DFT-S-OFDM based waveforms should be used at the UE. From one view, when the UE moves to the cell edge, the path loss becomes larger and it may be in power limited case. In this case, the DFT-s-OFDM based PHR may be more useful for the gNode-Bs (gNB) scheduling and power control. (gNB is the terminology used in 5G for base stations). From another view, the gNB can flexibly switch uplink transmission with different waveforms if it has both waveform specific PHR.

Figure 4 illustrates three different cases in which the waveform specific PHR can be used.

In case 1 the scheduled physical resource block (PRB) number may be changed according to the actual network load condition. When the UE 400 is located in the critical region 403 for both CP-OFDM and DFT-s-OFDM from a path loss/RSRP view, the gNB 401 has the ability to choose the transmission waveform and make flexible scheduling with a preferred PRB (physical resource block) number if two waveform specific PHRs are reported. CP-OFDM may be used in the case where there is a smaller scheduled bandwidth 405. DFT- s-OFDM may be used in the case where there is a larger scheduled bandwidth 407.

In case 2 when a multi-user multiple-input multiple-output (MU-MIMO) transmission is made, the same waveform is assumed for both UEs. The gNB 401 can make flexible MU- MIMO transmissions for a cell centre UE 409 and a cell edge UE 41 1 when the two waveform specific PHRs are reported from cell centre UEs. DFT-s-OFDM may be used for MU-MIMO and CP-OFDM may be used for single-user MIMO.

In case 3 when link adaptation is used, both single stream or multiple stream transmission can be supported for a cell edge UE. If DFT-s-OFDM waveform is configured for a cell edge UE 413, only a single stream transmission is currently proposed to be supported, according to current agreement. For the UE to be able to support multiple stream transmission, then the waveform must be switched to CP-OFDM. If CP-OFDM is configured for a cell edge UE 415 then multiple stream transmission will be supported. In this case, both DFT-s-OFDM and CP-OFDM PHR specific reporting may be beneficial for the gNB 401 , meaning the gNB 401 can be flexible when selecting a waveform and can support transmission with link adaptation.

Based on these three cases, it can be seen that the gNB 401 may have more scheduling flexibility when it is provided with both waveform specific PHR information.

In some embodiments, configurable waveform PHR reporting based on RSRP may be provided. This is shown in Figure 5. In some embodiments, there may be two working modes for waveform specific PHR reporting. In one mode the gNB 501 semi-statically configures the waveform for transmission. In this mode the UE reports one waveform specific PHR according to gNB's configuration. This mode may not provide enough power information for a dynamic change of the transmission waveform.

In another mode the gNB 501 dynamically selects the transmission waveform. The UE reports two waveform specific PHRs so that the gNB 501 can select a waveform. This mode allows for flexible waveform selection and is optimal for the network. However, the reporting signalling overhead is increased with this mode and there can be redundancy in some cases.

Some embodiments may have configurable one or two waveform specific PHR reporting system based on reference signal received power (RSRP).

In this regard, Figure 5 schematically shows a configurable one or two waveform specific PHR reporting system based on RSRP. The gNB is referenced 501 .

When the UE reported RSRP is smaller than one threshold value 7 , the gNB 501 will configure the UE 503 in region 1 to report DFT-s-OFDM based PHR. Region 1 is the outer region of the cell.

When UE reported RSRP is larger than a second threshold valuer ₂ , the gNB will configure UE 507 in region 3 to report CP-OFDM based PHR. Region 3 is the inner region of the cell.

When UE reported RSRP is between the first threshold value 7 and the second threshold valuer ₂ , the gNB will configure the UE 505 in region 2 to report both DFT-s-OFDM and CP-OFDM based PHRs. Region 2 is between the inner and outer regions of the cell.

In some embodiments, if threshold T ₂ is not provided, region 2 may be treated as part of region 3.

In some embodiments, if the threshold values 7 and T ₂ are the same, then the UE may just report one waveform specific PHR.

If a gNB wants to achieve flexible MU-MIMO for cell edge and cell centre user devices, both DTF-s-OFDM and CP-OFDM based PHRs should be reported for the cell centre UE. In this case, there is no need for the second threshold valuer ₂ . Thus, the second threshold value T ₂ may be an optional parameter in some embodiments.

If a gNB wants a cell edge user device to make flexible single or multiple stream transmission, both DTF-s-OFDM and CP-OFDM based PHRs should be reported for the cell edge UE. In this case, there is no need for the first threshold value 7 . Thus, the first threshold value T may be an optional parameter.

If the gNB does not want two waveform specific PHR reporting, it can set the same value for the first threshold value 7 and second threshold value T ₂ . In some embodiments, for a first scheme the gNB 501 determines which DFT-s-OFDM and CP-OFDM based PHR should be reported, this being based on the UE reported RSRP. The gNB 501 will notify the waveform selection result to the UE.

In another embodiment, for a second scheme the gNB 501 notifies the threshold values T and T ₂ for RSRP to the UE and the UE determines which DFT-s-OFDM and CP-OFDM based PHR are reported to the gNB 501 by comparing the threshold values and its measured results for RSRP. The UE will implement PHR reporting based on the waveform specific PHR reporting selection results, including periodic reporting and event triggering reporting.

Similarly as in the previous mentioned embodiment, if the gNB does not want two waveform specific PHR reporting, it can set the same value for the first threshold value 7 and second threshold value T ₂ . If the gNB wants to get more PHR information to make flexible transmissions, both the first threshold value 7 and the second threshold value T ₂ can be an optional value. If the first threshold value 7 is not signalled, the cell edge user will be reported with both DFT-s-OFDM and CP-OFDM based PHR for flexible single or multiple stream transmission. If the second threshold value T ₂ is not signalled, a cell centre user will be reported with both DFT-s-OFDM and CP-OFDM based PHR for flexible SU-MIMO and MU- MIMO transmission.

When a carrier aggregation scenario is considered, the thresholds for determining which waveform specific PHR for reporting is chosen, can be carrier specific on account of different path loss experienced for different carriers.

When a multiple beam scenario is considered, beam specific PHR can be reported. The thresholds for determining which waveform specific PHR for reporting is chosen, can be beam specific on account of different beamforming gain and thus different path loss for different beams. Embodiments may use two or more reference signals, for example where there is PHR reporting for two or more carriers/beams.

When two waveform specific PHRs are reported to the gNB, the reporting signalling overhead is twice the size in comparison to single waveform PHR reporting. Since using the DFT-s-OFDM waveform only, without CP-OFDM, is used for link budget limited cases, there may be some restriction for its transmission when multiple carriers are configured. Only the primary carrier may be used with the DFT-s-OFDM waveform for the limited link budget application scenario, in some embodiments. There may be no need for DFT-s-OFDM PHR reporting for other carriers. Thus, the UE may report all of the PHRs for CP-OFDM and just type 1 DFT-s-OFDM PHR for the primary carrier.

Figure 6 shows schematically some methods of reducing the signalling overhead for DFT-s-OFDM based PHR reporting. Some embodiments shown in Figure 6 may achieve some trade-off between reporting signalling overhead and flexible transmission with different waveforms.

Figure 6 shows different MAC (media access control) entities. The various fields are summarised below:

Q: this field indicates the presence of a PH field for the serving cell of any MAC entity, except the PCell. The C, field set to "1 " indicates that a PH field for the serving cell with SCelllndex i is reported. The C, field set to "0" indicates that a PH field for the serving cell with SCelllndex i is not reported;

R: reserved bit, set to "0";

- V: this field indicates if the PH value is based on a real transmission or a reference format. For Type 1 PH, V=0 indicates real transmission on PUSCH and V=1 indicates that a PUSCH reference format is used. For Type 2 PH, V=0 indicates real transmission on PUCCH and V=1 indicates that a PUCCH reference format is used. Furthermore, for both Type 1 and Type 2 PH, V=0 indicates the presence of the octet containing the associated P CMAX,C field, and V=1 indicates that the octet containing the associated P CMAX,C field is omitted;

Power Headroom (PH): this field indicates the power headroom level;

P: this field indicates whether power backoff due to power management is applied. The MAC entity shall set P=1 if the corresponding PCMAX,C field would have had a different value if no power backoff due to power management had been applied;

p

- PCMAX, _c : if present, this field indicates the PCMAX, _C or ^CMAX - ^c used for calculation of the preceding PH field.

If PUCCH and PUSCH can be supported to transmit on the same cell, additional type 2 DFT-s-OFDM based PHR for the primary carrier may be reported to the gNB. If limited carrier aggregation is supported, then additional type 1 DFT-s-OFDM based PHR for one configured carrier may be reported to the gNB.

Figure 6 illustrates that the PHR for DFT-s-OFDM and CP-OFDM can be reported in one united or two independent MAC control elements.

Fig 6a illustrates a scenario whereby there is only type 1 PHR reporting on the primary cell (PCell) for the DFT-s-OFDM waveform. Type 2 PHR will be reported on the PCell for CP- OFDM as well. Type 1 PHR will be reported on the PCell and the SCell for CP-OFDM.

Figure 6b illustrates scenario whereby type 1 and type 2 PHR will be reported on the primary cell for the DFT-s-OFDM waveform, when simultaneous PUCCH and PUSCH transmission is supported. Type 2 PHR will be reported on the PCell for CP-OFDM as well. Type 1 PHR will be reported on the PCell and the SCell for CP-OFDM.

Figure 6c illustrates embodiment scenario whereby type 1 and type 2 PHR report on the primary cell for DFT-s-OFDM Type 1 PHR will report on one configured cell for DFT-s- OFDM when limited CA is supported. Type 2 PHR will be reported on the PCell for CP-OFDM as well. Type 1 PHR will be reported on the PCell and the SCell for CP-OFDM.

In an LTE system, one triggering condition for PHR reporting is that the path loss has changed more than the dl-path loss change dB for at least one activated serving cell of any MAC entity. For DFT-s-OFDM, it is usually used for link budget limited cases and a small path loss change will cause a relatively large impact on the reliable transmission of the real link. For CP-OFDM, a small path loss change has only a little impact on the link quality. Thus, a different dl-path loss change can be introduced for different waveforms in the case of event triggering PHR reporting. When two waveform specific PHR are configured to be reported, two waveform specific PHRs need to be reported even if the triggering condition is met by only one waveform specific PHR. This may provide more power information for scheduling.

Thus some embodiments may provide configurable one or two waveform specific PHR reporting based on RSRP. Some embodiments may provide a signalling reduction for DFT-s- OFDM based PHR reporting, e.g. just type 1 PHR for the primary carrier. Some embodiments may have waveform specific dl path loss change, and joint reporting for two waveform specific PHRs even if only one waveform specific PHR is triggered.

Fig 7 shows a flowchart whereby the PHR for DFT-s-OFDM and CP-OFDM can be reported in one united or two independent MAC control elements. The gNB sends signalling to the UE to indicate which waveform specific PHR for reporting is chosen based on RSRP value.

At step 701 the UE reports the measured RSRP value to the gNB.

At step 702 it is determined whether the RSRP is smaller than a first threshold value (Ti ). In this embodiment, this is performed in the gNB.

If the RSRP value is less than the first threshold value, then the next step is step 703, where the UE is configured to report DFT-s-OFDM based PHR to the gNB. If it is determined that in step 702 that the RSRP value is larger than the first threshold value Ti , then the next step is step 704.

At step 704 it is determined in the gNB whether the RSRP is larger than a second threshold value. If the RSRP value is larger than the second threshold valueT ₂ , then the next step is step 705, the UE will be configured to report CP-OFDM based PHR to the gNB. If the RSRP value is smaller than the second threshold value, meaning Ti < RSRP < T ₂ , then at step 706, the UE will be configured to report both DFT-s-OFDM and CP-OFDM based PHR to the gNB.

The signalling details may be: 0 for DFT-s-OFDM based PHR reporting; 1 for CP- OFDM based PHR reporting; 2 for both DFT-s-OFDM and CP-OFDM based PHR reporting. Of course different values may be used for the different reporting in different embodiments. The UE may make PHR reporting according to gNB' s indication as to which waveform specific PHR(s) reporting is to be used.

When the gNB signals to the UE which waveform specific PHR it requires the signalling may be dynamic or high layer signalling.

Figure 8 shows a flowchart for an alternate embodiment whereby the PHR for DFT-s-

OFDM and CP-OFDM can be reported in one united or two independent MAC control elements.

At step 801 the gNB transmits the two threshold values Ti and T ₂ to the UE. The UE will determine how the measured RSRP value compares with the threshold values.

At step 802 the UE will determine whether the RSRP value is smaller than the first threshold value Ti .

At step 803, if the value is smaller than the first threshold (Ti ), then the UE will report DFT-s-OFDM based PHR to the gNB.

If the value is larger than the first threshold value Ti , then at step 804 it is determined whether the RSRP is larger than the second threshold value T ₂ .

If the RSRP value is larger than the second threshold valueT ₂ , then at step 806 the UE will report CP-OFDM based PHR to the gNB.

If the RSRP value is smaller than the second threshold value T ₂ , meaning Ti < RSRP < T ₂ , then at step 805, the UE will report both DFT-s-OFDM and CP-OFDM based PHR to the gNB.

The thresholds sent to the UE may be carrier specific in a carrier aggregation scenario.

The gNB may configure the waveform specific dl path loss change, i.e. dl path loss changel for DFT-s-OFDM and dl path loss change2 for CP-OFDM. This may be an event trigger condition which may be used in some embodiments.

When the periodic PHR-Timer expires, the UE may perform PHR reporting according to gNB' s configuration of which waveform specific PHR is to be used for reporting. In some embodiments, independent or separate timers may be provided for the different waveforms.

When DFT-s-OFDM based PHR reporting is made, the available PHR reporting scheme in LTE system may be used.

When CP-OFDM based PHR reporting is made, the available PHR reporting scheme in LTE system can be used with DFT-s-OFDM based PHR being changed to CP-OFDM based PHR;

When both DFT-s-OFDM and CP-OFDM based PHR reporting is made, one or more of the following schemes can be used with potential trade-offs between flexibility usage for waveform and reporting signalling overhead:

i. CP-OFDM based PHR reporting and DFT-s-OFDM based type 1 PHR for primary cell (base scheme); ii. CP-OFDM based PHR reporting and DFT-s-OFDM based type 1 and type 2 PHR for primary cell in case of supporting simultaneous transmission for PUCCH and PUSCH;

Hi. CP-OFDM based PHR reporting and DFT-s-OFDM based type 1 and type 2 PHR for primary cell and one configured cell in case of supporting limited carrier aggregation;

In some embodiments the definition of Type 1 and type 2 PHR may be the same as the LTE system, for example specified in TS36.213. However, this is by way of example and in some embodiments, one or of more of the type 1 and type 2 characteristics may be differ from the LTE system.

Fig 9 shows a flowchart of a method when a waveform specific prohibit PHR-timer expires or has expired.

At step 901 , when the timer has expired and when only DFT-s-OFDM based PHR is configured to report to the gNB, it is determined if the path loss has changed more than dl- path loss Changel dB. If so the UE will report event triggered PHR in the same manner as for example LTE system in step 904.

At step 902, when the timer has expired and when only CP-OFDM based PHR is configured to report to the gNB and it is determined if the path loss has changed more than dl-path loss change2 dB. If so, the UE will report event triggered PHR similar to the LTE system but changing DFT-s-OFDM based PHR to CP-OFDM based PHR in step 905.

At step 903 when any timer for both CP-OFDM and DFT-s-OFDM PHR reporting has expired and when both CP-OFDM and DFT-s-OFDM based PHR are configured to report to the gNB, it is determined if the path loss has changed and the path loss has changed more than dl-path loss changel or dl-path loss change 2 dB, the UE will report event triggered PHR including both DFT-s-OFDM based PHR and CP-OFDM based PHR at step 906.

Some embodiments may thus have waveform specific dl-Path loss Change values. Some embodiments may have joint reporting for two waveform specific PHRs even if only one waveform specific PHR is triggered

Some embodiments may have one or more of the following advantages: Provide enough power information for flexible selection of transmission waveform for UE;

Achieve performance gain by flexible usage of waveform; and

Achieve good trade-off between reporting signalling overhead and transmission flexibility for different waveforms.

In the previously described embodiments, RSRP is used to control the PHR reporting. In other embodiments, one or more different measures or parameters may alternatively or additionally be used. For example, path loss may be used. Other embodiments may use RSRQ (reference signal received quality), CQI (channel quality indicator) etc. Embodiments may use any suitable measure or parameter reflection a quality of a channel. In t e previously described embodiments, CP-OFDM or DFT-S-OFDM waveforms have been the two available waveforms. It should be appreciated that different wave forms may be used in different embodiments. This may be in the context of a 5G system or a different system. In some embodiments CP-OFDM and one or more other waveforms may be available to use. In some embodiments DFT-S-OFDM and one or more other waveforms may be available to use. The number of waveforms may be more than two in some embodiments.

It is noted that whilst embodiments have been described in relation to 5G networks, similar principles can be applied in relation to other networks and communication systems, for example, other implementations new radio networks, or Ml MO systems in LTE networks. It should be appreciated that other embodiments may be used with any other suitable system where two or more different waveforms can be used.

It is noted that whilst embodiments have been described in relation to 5G networks, similar principles can be applied in coexistence with the LTE system and 5G system. For the LTE system in one carrier, DFT-s-OFDM based PHR is reported similarly as LTE mechanism. For the 5G system in another carrier, configured PHR modes can be used as previously described, where DFT-s-OFDM and CP-OFDM based 5G PHR will be reported. Here, LTE based PHR/5G based PHR are computed based on a LTE/5G power control scheme and power splitting scheme between LTE and 5G modules Therefore, although certain embodiments were described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, embodiments may be applied to any other suitable forms of communication systems than those illustrated and described herein.

In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The embodiments of this invention may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and/or macros, may be stored in any apparatus-readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computer- executable components which, when the program is run, are configured to carry out embodiments. The one or more computer-executable components may be at least one software code or portions of it.

Further in this regard it should be noted that any blocks of the logic flow as in the

Figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The physical media is a non-transitory media.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), FPGA, gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

The foregoing description has provided by way of non-limiting examples a full and informative description of the exemplary embodiment of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention as defined in the appended claims. Indeed there is a further embodiment comprising a combination of one or more embodiments with any of the other embodiments previously discussed.