WO2020164028A1

WO2020164028A1 - Power control in uplink transmission

Info

Publication number: WO2020164028A1
Application number: PCT/CN2019/074998
Authority: WO
Inventors: Chunli Wu; Benoist Sebire; Samuli Turtinen
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Priority date: 2019-02-13
Filing date: 2019-02-13
Publication date: 2020-08-20
Anticipated expiration: 2021-08-13
Also published as: CN113228749A

Abstract

Embodiments of the disclosure provide a method, device and computer readable medium for power reduction indication. According to embodiments of the present disclosure, the terminal device transmits an indication of power reduction to the network device if the terminal device needs to reduce transmission power. The network device performs communication with the terminal device based on the indication of power reduction. In this way, the power control is improved by taking the power reduction into consideration.

Description

POWER CONTROL IN UPLINK TRANSMISSION

FIELD

Embodiments of the present disclosure generally relate to communication techniques, and more particularly, to methods, devices and computer readable medium for power headroom report.

BACKGROUND

In recent communication networks, several technologies of power management have been proposed. For example, a network device allocates bandwidths and required power for uplink transmission to terminal devices. The terminal devices may report information about the power headroom to the network device. Upon receipt of the information, the network device may control power based on the power headroom. Such a power control scheme is generally not so accurate.

SUMMARY

Generally, embodiments of the present disclosure relate to a method for power reduction indication and the corresponding communication devices.

In a first aspect, embodiments of the disclosure provide a terminal device. The terminal device comprises: at least on processor; and a memory coupled to the at least one processor, the memory storing instructions therein, the instructions, when executed by the at least one processor, causing the terminal device to: receive, at the terminal device and from a network device, first information of a required transmission power. The required transmission power is a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device. The network device is further caused to compare the required transmission power with a maximum transmission power of the terminal device. The network device is also caused to in response to the required transmission power exceeding the maximum transmission power, transmit, to the network device, second information comprising an indication of power reduction for the uplink transmission in the cell.

In a second aspect, embodiments of the disclosure provide a network device. The network device comprises: at least on processor; and a memory coupled to the at least one processor, the memory storing instructions therein, the instructions, when executed by the at least one processor, causing the network device to. : transmit, at the network device and to a terminal device, first information of a required transmission power. The required transmission power is a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device. The network device is also caused to receive, from the terminal device, second information comprising an indication of power reduction for the uplink transmission in the cell. The network device is further caused to perform communication with the terminal device based on the indication.

In a third aspect, embodiments of the present disclosure provide a method. The method comprises: receiving, at a terminal device and from a network device, first information of a required transmission power. The required transmission power is a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device. The method also comprises comparing the required transmission power with a maximum transmission power of the terminal device. The method further comprises in response to the required transmission power exceeding the maximum transmission power, transmitting, to the network device, second information comprising an indication of power reduction for the uplink transmission in the cell.

In a fourth aspect, embodiments of the present disclosure provide a method. The method comprises: transmitting, at a network device and to a terminal device, first information of a required transmission power. The required transmission power is a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device. The method also comprises receiving, from the terminal device, second information comprising an indication of power reduction for the uplink transmission in the cell. The method further comprises performing communication with the terminal device based on the indication.

In a fifth aspect, embodiments of the disclosure provide an apparatus. The apparatus comprises means for receiving, at a terminal device and from a network device, first information of a required transmission power. The required transmission power is a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device. The apparatus further comprises means for comparing the required transmission power with a maximum transmission power of the terminal device. The apparatus also comprises means for means for in response to the required transmission power exceeding the maximum transmission power, transmitting, to the network device, second information comprising an indication of power reduction for the uplink transmission in the cell.

In a sixth aspect, embodiments of the disclosure provide an apparatus. The apparatus comprises means for transmitting, at a network device and to a terminal device, first information of a required transmission power. The required transmission power is a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device. The apparatus also comprises means for receiving, from the terminal device, second information comprising an indication of power reduction for the uplink transmission in the cell. The apparatus further comprises means for performing communication with the terminal device based on the indication.

In a seventh aspect, embodiments of the disclosure provide a computer readable medium. The computer readable medium stores instructions thereon, the instructions, when executed by at least one processing unit of a machine, causing the machine to implement the method according to the third aspect or the fourth aspect.

Other features and advantages of the embodiments of the present disclosure will also be apparent from the following description of specific embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the disclosure are presented in the sense of examples and their advantages are explained in greater detail below, with reference to the accompanying drawings, where

Fig. 1 illustrates a schematic diagram of a PHR Medium Access Control (MAC) Control Element (CE) ;

Fig. 2 illustrates a schematic diagram of a further PHR MAC CE;

Fig. 3 illustrates a schematic diagram of another PHR MAC CE;

Fig. 4 illustrates a schematic diagram of a communication system according to embodiments of the present disclosure;

Fig. 5 illustrates a schematic diagram of interactions among devices according to embodiments of the present disclosure;

Fig. 6 illustrates a flow chart of a method implemented at a communication device according to embodiments of the present disclosure;

Fig. 7 illustrates a flow chart of a method implemented at a communication device according to embodiments of the present disclosure;

Fig. 8 illustrates a schematic diagram of a device according to embodiments of the present disclosure; and

Fig. 9 shows a block diagram of an example computer readable medium in accordance with some embodiments of the present disclosure.

Throughout the figures, same or similar reference numbers indicate same or similar elements.

DETAILED DESCRIPTION OF EMBODIMENTS

The subject matter described herein will now be discussed with reference to several example embodiments. It should be understood these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the subject matter described herein, rather than suggesting any limitations on the scope of the subject matter.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a, ” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises, ” “comprising, ” “includes” and/or “including, ” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.

It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two functions or acts shown in succession may in fact be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , New Radio (NR) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the future fifth generation (5G) communication protocols, and/or any other protocols either currently known or to be developed in the future.

Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system. For the purpose of illustrations, embodiments of the present disclosure will be described with reference to 5G communication system.

The term “network device” used herein includes, but not limited to, a base station (BS) , a gateway, a registration management entity, and other suitable device in a communication system. The term “base station” or “BS” represents a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, a low power node such as a femto, a pico, and so forth.

The term “terminal device” used herein includes, but not limited to, “user equipment (UE) ” and other suitable end device capable of communicating with the network device. By way of example, the “terminal device” may refer to a terminal, a Mobile Terminal (MT) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) .

The term “circuitry” used herein may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with

software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. ”

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As mentioned above, the terminal devices may report the power headroom to the network device. Power Headroom Reports (PHRs) are reported by the terminal device to the network to enable efficient scheduling of uplink. The PHR may be triggered by some conditions. For example, the PHR may be triggered by Pathloss (PL) change being above a threshold. Alternatively, the PHR may be triggered by periodic timer expiry.

In conventional technologies, the terminal device may transmit the PHR for one cell or multiple cells. Fig. 1 illustrates a schematic diagram of a single entry PHR MAC CE. Fig. 2 illustrates a schematic diagram of multiple entries PHR MAC CE with the highest index of a serving cell (also referred to as ServCell Index) with configured uplink less than 8. Fig. 3 illustrates a schematic diagram of multiple entries PHR MAC CE with the highest ServCell Index of a serving cell with configured uplink is equal to or higher than 32. It should be note that the ServCell Index and numbers shown with respect to Figs. 1-3 are only for the purpose of illustrations, rather than limitations.

Different types of PHR are defined: Type 1 Power Headroom is defined as the remaining power depending on Physical Uplink Shared Channel (PUSCH) transmission power; type 2 PHR is defined as remaining power depending on PUCCH transmission power and type 3 PHR is defined as remaining power depending on SRS transmission. Real and virtual PHR are defined depending on whether there is actual UL transmission on the related channel. Taking Type 1 PHR as an example: If a UE determines that a Type 1 power headroom report for an activated serving cell is based on an actual PUSCH transmission then, for PUSCH transmission occasion i on active uplink (UL) bandwidth part (BWP) b of carrier f of serving cell c, the UE computes the Type 1 power headroom report as below:

where P _CMAX, f, c (i) is the configured UE transmit power defined for carrier f of serving cell c in PUSCH transmission occasion i;

is a parameter composed of the sum of a component P _{O_NOMINAL_PUSCH, f, c} (j) and a component P _{O_UE_PUSCH, b, f, c} (j) where j∈ {0, 1, ..., J-1} ;

is the bandwidth of the PUSCH resource assignment expressed in number of resource blocks for PUSCH transmission occasion i on active UL BWP b of carrier f of serving cell c and μ is a subcarrier spacing configuration; PL _b, f, c (q _d) is a downlink pathloss estimate in dB calculated by the UE using reference signal (RS) index q _d for the active DL BWP of serving cell c;

for K _S = 1.25 and Δ _{TF, b, f, c} (i) = 0 for K _S = 0 where K _S is provided by higher layer parameter deltaMCS for each UL BWP b of each carrier f and serving cell c; f _b, f, c (i, l) is the PUSCH power control adjustment state l for active UL BWP b of carrier f of serving cell c and PUSCH transmission occasion i if the UE is provided higher layer parameter tpc-Accumulation.

The PUSCH transmission power is defined as below, which depends on the bandwidth of PUSCH resource allocation

pathloss (PL) as well as the accumulated power control command affect. For example, if a UE transmits a PUSCH on active UL BWP b of carrier f of serving cell c using parameter set configuration with indexj and PUSCH power control adjustment state with index l, the UE determines the PUSCH transmission power P _{PUSCH, b, f, c} (i, j, q _d, l) in PUSCH transmission occasion i as below:

For dual connectivity (for example, E-UTRAN New Radio -Dual Connectivity (EN-DC) and NE-DC) , power reduction may happen when the total power exceed the UE power.

In the scenario of EN-DC, if the UE indicates a capability for dynamic power sharing between E-UTRA and NR for EN-DC and if UE transmission (s) in subframe i ₁ of the MCG overlap in time with UE transmission (s) in slot i ₂ of the SCG in FR1, and if

in any portion of slot i ₂ of the SCG, the UE reduces transmission power in any portion of slot i ₂ of the SCG so that

in any portion of slot i ₂, where

and

are the linear values of the total UE transmission powers in subframe i ₁ of the MCG and in slot i ₂ of the SCG in FR1, respectively. The UE is not required to transmit in any portion of slot i ₂ of the SCG if

would need to be reduced by more than the value provided by X _SCALE in order for

in any portion of slot i ₂ of the SCG. The UE is required to transmit in slot i ₂ of the SCG if

would not need to be reduced by more than the value provided by X _SCALE in order for

in all portions of slot i ₂

In the scenario of NE-DC, if the UE indicates a capability for dynamic power sharing between E-UTRA and NR and if the UE transmission (s) in subframe i ₁ of the MCG overlap in time with UE transmission (s) in slot i ₂ of the SCG in frequency range 1, and if

in any portion of slot i ₂ of the SCG, the UE reduces transmission power in any portion of slot i ₁ of the MCG so that

in all portions of slot i ₁, where

and

are the linear values of the total UE transmission powers in slot i ₁ of the MCG in FR1 and in subframe i ₂ of the SCG, respectively.

Further, the PHR report can be large with carrier aggregation (CA) and/or dual connectivity (DC) configurations. The likelihood of a triggered PHR not being able to be included in the MAC PDU increases along with increasing the number of configured carriers. With 32 serving cells, the PHR MAC CE can be over 60 bytes. According to current technologies, the PHR is only included when the whole PHR MAC CE can be included in the PDU.

In the scenario of truncated PHR, the power headroom (PH) of some cells may be reported when the full PHR cannot fit into the MAC PDU. When power reduction happens, the network device would not be able to know if current allocation and power control is proper based on the PH of the reported cells even if the PH values indicate there is still power left, since the reduction of transmission power is not taken into account.

According to embodiments of the present disclosure, the terminal device transmits an indication of power reduction to the network device if the terminal device needs to reduce transmission power. The network device performs communication with the terminal device based on the indication of power reduction. In this way, the power reduction is taken into consideration during the power control, and thus the UL scheduling is improved.

Fig. 4 illustrates a schematic diagram of a communication system 400 in which embodiments of the present disclosure can be implemented. The communication system 400, which is a part of a communication network, comprises terminal devices 410-1, 410-2, ..., 410-N (collectively referred to as “terminal device (s) 410” where N is an integer number) . The communication system 400 comprises one or more network devices, for example, network devices 420-1, 420-2, ..., 420-M (collectively referred to as “network device (s) 420” where M is an integer number) . It should be understood that the communication system 400 may also comprise other elements which are omitted for the purpose of clarity. It is to be understood that the numbers of terminal devices and network devices shown in Fig. 4 are given for the purpose of illustration without suggesting any limitations. The network device 420 may communicate with the terminal devices 410.

Communications in the communication system 400 may be implemented according to any proper communication protocol (s) , including, but not limited to, cellular communication protocols of the first generation (1G) , the second generation (2G) , the third generation (3G) , the fourth generation (4G) and the fifth generation (5G) and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, including but not limited to: Code Divided Multiple Address (CDMA) , Frequency Divided Multiple Address (FDMA) , Time Divided Multiple Address (TDMA) , Frequency Divided Duplexer (FDD) , Time Divided Duplexer (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Divided Multiple Access (OFDMA) and/or any other technologies currently known or to be developed in the future.

Fig. 5 illustrates a schematic diagram of interactions 500 in accordance with embodiments of the present disclosure. The interactions 500 may be implemented at any suitable devices. Only for the purpose of illustrations, the interactions 500 are described to be implemented at the terminal device 410-1 and the network device 420-1.

The network device 420-1 transmits 505 first information of required transmission power. The required power is required by the network device for performing uplink transmission. In some embodiments, the first information may indicate the required power for one cell 430-1 which is managed by the network device 420-1. In other embodiments, the first information may indicate the required power for several cells, for example, cells 430-1 and 430-2. In some embodiments, the cells 430-1 and 430-2 may be managed by the network device 420-1. Alternatively, the cells 430-1 and 430-2 may be managed by different network devices, for example, the network devices 420-1 and 420-2.

The terminal device 410-1 compares 510 the required transmission power with a maximum transmission power of the terminal device 410-1. The maximum transmission power is the power that the terminal device 410-1 is able to provide for uplink transmissions.

If the terminal device 410-1 determines that the required transmission power exceeds the maximum transmission power, the terminal device 410-1transmits 515 second information to the network device 420-1. The second information comprises an indication of power reduction. The indication of power reduction may be transmitted using reserved bit (s) from Pcmax, c octet. In some embodiments, the second information may be transmitted via the PHR. In other embodiments, the power reduction may trigger a PHR. The second information may indicate per serving cell whether power scaling is applied for each serving cell with PH reported. In this way, the power reduction/scaling is transmitted to the network device for further power control.

In some embodiments, the terminal device 410-1 may determine 520 which cell (s) and/or channel (s) is to perform power reduction based on predetermined rules. For example, if the cell 430-1 is a primary cell and the cell 430-2 is a secondary cell, the terminal device 410-1 may reduce 525 the transmission power on the cell 430-2.

In some other embodiments, if the cell 430-1 is a cell in a long-term evolution (LTE) network and the cell 430-2 is a cell in a new radio (NR) network, the terminal device 410-1 may reduce 525 the transmission power on the cell 430-2.

In some embodiments, the channels may comprise a plurality of channels, for example, one or more of: PUSCH, physical uplink control channel (PUCCH) and physical random access channel (PRACH) . If the required power exceeds the maximum transmission power, the terminal device 410-1 may reduce 525 transmission power on the PUSCH other than PUCCH/PRACH based on their priorities.

The network device 420-1 performs 530 communication with the terminal device 410-1 based on the received indication of power reduction. The network device 420-1 may perform UL scheduling based on the indication. In some embodiments, the network device 420-1 may reduce PUSCH allocation bandwidth to the terminal device 410-1. Alternatively, if the network device 420-1 receives the indication of power reduction, the network device 420-1 may not transmit power control command to increase/decrease the transmission power to the terminal device 410-1.

Fig. 6 illustrates a flow chart of a method 600 in accordance with embodiments of the present disclosure. The method 600 may be implemented at any suitable devices. Only for the purpose of illustrations, the method 600 is described to be implemented at the terminal device 410-1.

At block 610, the terminal device 410-1 receives first information of a required transmission power. The required transmission power is required by the network device for performing uplink transmission. In some embodiments, the first information may indicate the required power for one cell 430-1 which is managed by the network device 420-1. In other embodiments, the first information may indicate the required power for several cells, for example, cells 430-1 and 430-2.

At block 620, the terminal device 410-1 compares the required transmission power with a maximum transmission power of the terminal device 410-1. The maximum transmission power is the power that the terminal device 410-1 is able to provide for uplink transmissions.

If the terminal device 410-1 determines that the required transmission power exceeds the maximum transmission power, the terminal device 410-1 transmits, at block 630, second information to the network device 420-1. The second information comprises an indication of power reduction. The indication of power reduction may be transmitted using reserved bit (s) from P _cmax, c octet in PHR. In other embodiments, the power reduction may trigger a PHR. The second information may indicate per serving cell whether power scaling is applied for each serving cell with PH reported. In this way, the power reduction/scaling is transmitted to the network device for further power control.

In some embodiments, the terminal device 410-1 may determine which cell (s) is to perform power reduction based on predetermined rules, for example, priorities. For example, if the cell 430-1 is a primary cell and the cell 430-2 is a secondary cell, the terminal device 410-1 may reduce the transmission power on the cell 430-2.

In other embodiments, if the cell 430-1 is a cell in a long-term evolution (LTE) network and the cell 430-2 is a cell in a new radio (NR) network, the terminal device 410-1 may reduce the transmission power on the cell 430-2.

In some embodiments, when power reduction needs to be performed by the terminal device, the PHR may be triggered to be transmitted to the network device. In some examples, the power headroom report is triggered in case power reduction needs to be applied for multiple serving cells or threshold number of serving cells where such threshold number could be configurable by the network devices. In some examples, the power headroom report is triggered in case power reduction is applied for PCell, PSCell, and/or SCell (s) .

In an example embodiment of the present disclosure, it introduces truncated PHR to enable reporting partial PHR when the full PHR MAC CE cannot fit into the MAC PDU. The truncated PHR may not cancel the triggered PHR and it may remain pending until the full report can be multiplexed into a MAC PDU.

The truncated PHR can also indicate explicitly that PHR was triggered but did not fit to the available resources (for example, in case it is included when padding is available) . For instance, with a different logical channel identify (LCID) or the reserved bit in the bitmap in the multiple entry PHR format may be used for this purpose or one of the reserved bits before power headroom (PH) value in the single entry PHR format.

In one embodiment, the terminal device 410-1 may set the bit in the bitmap for every activated serving cell (as currently) but reports the PH for as many as it can fit before the available bytes in the MAC PDU are exhausted. The terminal device 410-1 may report the cells based on strict priority rules based on which the network device determines which serving cells are actually reported. This is especially useful to give the network device knowledge of how many serving cells are activated in the other cell group in dual connectivity, for instance.

In the scenario of reporting truncated PHR, reporting the cells having real PUSCH transmission may be prioritized since the power reduction only happens for the cells with real PUSCH transmissions. In addition, the terminal device 410-1 may transmit PHR for the cells where power reduction is applied rather than the cells without power reduction.

To reduce overhead, some of the rules for truncated PHR may be applicable to regular triggered PHR as well, for example, rules on explicit configurations of a subset of cells to be reported in the PHR or explicitly configured only a subset of cells are to be reported in PHR.

In some embodiments, the cells to be reported in the truncated PHR may be selected with one or more of the following rules:

(1) The cells within the same MAC entity (that is, the same cell group) are prioritized over cells of the other MAC entity (i.e. the other cell group) ;

(2) PCell/PSCell is prioritized over SCells;

(3) According to the PH type/value, e.g. real/virtual, type 1/2/3: (a) The cells with actual UL transmission resources at the time the PHR is transmitted are prioritized, that is, the cells with real PH reported, not the ones with virtual PHR; (b) Type 1 PH is prioritized over Type 3 for any cell; (c) The cells with applied or not applied power backoff are prioritized; (d) The cells with lowest PH value are prioritized; (e) The cells with a PH that has changed the most compared to the last PHR are prioritized;

(4) According to cell index or frequency/band of the cell: (a) Ascending/descending order of the cell index. The cells with lowest serving cell indices (to be able to use 8 bit bitmap multiple entry PHR format instead of 32 bit bitmap multiple entry PHR format) are prioritized; (b) Ascending/descending order of the frequency/band of the cells. One cell per band, the cell with lowest/highest cell index within each band is reported;

(5) Explicitly indicated whether PH for the cell shall be reported when the cell is configured;

(6) The newly activated SCell (s) , in case PHR was triggered due to SCell activation;

(7) The SCells in the order of configuration;

(8) The SCells in the order of numerology;

(9) The SCells in the order of BWP size.

In some embodiments, the terminal device 410-1 may perform uplink transmission only in one cell. The terminal device 410-1 may determine on which channel (s) the power reduction is performed base on predetermined rules. For example, the channels may comprise a plurality of channels, for example, one or more of: PUSCH, physical uplink control channel (PUCCH) and physical random access channel (PRACH) . If the required power exceeds the maximum transmission power, the terminal device 410-1 may determine to reduce transmission power on the PUSCH other than PUCCH/PRACH based on their priorities.

Alternatively or in addition, the second information may also comprise the amount of the power reduction. In some embodiments, the amount of the power reduction may be transmitted using the PH field. In other embodiments, the amount of power reduction may be transmitted using the PCmax field. In this way, the network device knows the amount of the power reduction which is used to improve power scheduling.

In an example embodiment, the second information may also comprise the cause for the power reduction. For example, the cause may comprise overheating. Alternatively or in addition, the cause may comprise TX over another cell group/MAC entity. In this way, the network device has information of the transmission conditions, thereby improving the transmissions between the network device and the terminal device.

In some embodiments, an apparatus for performing the method 600 (for example, the terminal device 110-1) may comprise respective means for performing the corresponding steps in the method 600. These means may be implemented in any suitable manners. For example, it can be implemented by circuitry or software modules.

In some embodiments, the apparatus comprises means for receiving, at a terminal device and from a network device, first information of a required transmission power, the required transmission power being a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device; means for comparing the required transmission power with a maximum transmission power of the terminal device; and means for in response to the required transmission power exceeding the maximum transmission power, transmitting, to the network device, second information comprising an indication of power reduction for the uplink transmission in the cell.

In some embodiments, the second information further comprises at least one of: an amount of the power reduction, and a cause for the power reduction.

In some embodiments, the apparatus further comprises: means for determining a priority of the cell based on a type of the cell; and means for in response to the priority of the cell being higher than a priority of a further cell managed by the network device, reducing a transmission power of the terminal device in the further cell.

In some embodiments, the apparatus further comprises: means for determining first and second priorities of first and second channels used by the terminal device in the cell based on types of the first and second channels; and means for in response to the first priority being higher than the second priority, reducing a transmission power of the terminal device on the second channel.

In some embodiments, the second information is transmitted in a power headroom report (PHR) .

Fig. 7 illustrates a flow chart of a method 700 in accordance with embodiments of the present disclosure. The method 700 may be implemented at any suitable devices. Only for the purpose of illustrations, the method 700 is described to be implemented at the network device 420-1.

At block 710, the network device 420-1 transmits first information of required transmission power. The required power is required by the network device for performing uplink transmission. In some embodiments, the first information may indicate the required power for one cell 430-1 which is managed by the network device 420-1. In other embodiments, the first information may indicate the required power for several cells, for example, cells 430-1 and 430-2.

At block 720, the network device 420-1 receives second information comprising an indication of power reduction for the transmission in the cell. The second information comprises an indication of power reduction. The indication of power reduction may be transmitted using reserved bit (s) from P _cmax, c octet. In some embodiments, the second information may be received via the PHR. The second information may indicate that power scaling is applied for each serving cell with PH reported. In this way, the network device knows power reduction happened.

Alternatively or in addition, the second information may also comprise the amount of the power reduction. In some embodiments, the amount of the power reduction may be transmitted using the PH value. In other embodiments, the amount of power reduction may be transmitted using the PCmax field.

In an example embodiment, the second information may also comprise the cause for the power reduction. For example, the cause may comprise overheating. Alternatively or in addition, the cause may comprise TX over another cell group/MAC entity. In this way, the network device also knows the reason for the power reduction.

At block 730, the network device 420-1 performs communication with the terminal device 410-1 based on the indication. The network device 420-1 may perform power scheduling based on the indication. In some embodiments, the network device 420-1 may reduce PUSCH allocation bandwidth to the terminal device 410-1. Alternatively, if the network device 420-1 receives the indication of power reduction, the network device 420-1 may not transmit power control command to increase the transmission power to the terminal device 410-1.

In some embodiments, the apparatus comprises means for transmitting, at a network device and to a terminal device, first information of a required transmission power, the required transmission power being a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device; means for receiving, from the terminal device, second information comprising an indication of power reduction for the uplink transmission in the cell; and means for performing communication with the terminal device based on the indication.

In some embodiments, the means for performing communication with the terminal device comprises: means for reducing physical uplink shared channel (PUSCH) allocation bandwidth for the terminal device.

In some embodiments, the second information is received in a power headroom report (PHR) .

Fig. 8 is a simplified block diagram of a device 800 that is suitable for implementing embodiments of the present disclosure. The device 800 may be implemented at the network device 120. The device 800 may also be implemented at the terminal devices 110. As shown, the device 800 includes one or more processors 810, one or more memories 820 coupled to the processor (s) 810, one or more transmitters and/or receivers (TX/RX) 840 coupled to the processor 810.

The processor 810 may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 800 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 820 may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples.

The memory 820 stores at least a part of a program 830. The device 800 may load the program 830 from the computer readable medium to the RAM for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. Fig. 9 shows an example of the computer readable medium 800 in form of CD or DVD. The computer readable medium has the program 830 stored thereon.

The TX/RX 840 is for bidirectional communications. The TX/RX 840 has at least one antenna to facilitate communication, though in practice an Access Node mentioned in this application may have several ones. The communication interface may represent any interface that is necessary for communication with other network elements.

The program 830 is assumed to include program instructions that, when executed by the associated processor 810, enable the device 800 to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to Figs. 5 and 7. That is, embodiments of the present disclosure can be implemented by computer software executable by the processor 810 of the device 800, or by hardware, or by a combination of software and hardware.

While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any disclosure or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular disclosures. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

Various modifications, adaptations to the foregoing exemplary embodiments of this disclosure may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings. Any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this disclosure. Furthermore, other embodiments of the disclosures set forth herein will come to mind to one skilled in the art to which these embodiments of the disclosure pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.

Therefore, it is to be understood that the embodiments of the disclosure are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are used herein, they are used in a generic and descriptive sense only and not for purpose of limitation.

Claims

A terminal device, comprising:

at least one processor; and

a memory coupled to the at least one processor, the memory storing instructions therein, the instructions, when executed by the at least one processor, causing the terminal device to:

receive, at the terminal device and from a network device, first information of a required transmission power, the required transmission power being a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device;

compare the required transmission power with a maximum transmission power of the terminal device; and

in response to the required transmission power exceeding the maximum transmission power, transmit, to the network device, second information comprising an indication of power reduction for the uplink transmission in the cell.
The terminal device of claim 1, wherein the second information further comprises at least one of:

an amount of the power reduction, and

a cause for the power reduction.
The terminal device of claim 1, wherein the device is further caused to:

determine a priority of the cell based on a type of the cell; and

in response to the priority of the cell being higher than a priority of a further cell, reduce a transmission power of the terminal device in the further cell.
The terminal device of claim 1, wherein the device is further caused to:

determine first and second priorities of first and second channels used by the terminal device in the cell based on types of the first and second channels; and

in response to the first priority being higher than the second priority, reduce a transmission power of the terminal device on the second channel.
The terminal device of claim 1, wherein the second information is transmitted in a power headroom report (PHR) .
A network device, comprising:

at least one processor; and

a memory coupled to the at least one processor, the memory storing instructions therein, the instructions, when executed by the at least one processor, causing the network device to:

transmit, at the network device and to a terminal device, first information of a required transmission power, the required transmission power being a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device;

receive, from the terminal device, second information comprising an indication of power reduction for the uplink transmission in the cell; and

perform communication with the terminal device based on the indication.
The network device of claim 6, wherein the second information further comprises at least one of:

an amount of the power reduction, and

a cause for the power reduction.
The network device of claim 6, wherein the network device is caused to perform communication with the terminal device by:

reducing physical uplink shared channel (PUSCH) allocation bandwidth for the terminal device.
The network device of claim 6, wherein the second information is received in a power headroom report (PHR) .
A method, comprising:

receiving, at a terminal device and from a network device, first information of a required transmission power, the required transmission power being a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device;

comparing the required transmission power with a maximum transmission power of the terminal device; and

in response to the required transmission power exceeding the maximum transmission power, transmitting, to the network device, second information comprising an indication of power reduction for the uplink transmission in the cell.
The method of claim 10, wherein the second information further comprises at least one of:

an amount of the power reduction, and

a cause for the power reduction.
The method of claim 10, further comprising:

determining a priority of the cell based on a type of the cell; and

in response to the priority of the cell being higher than a priority of a further cell, reducing a transmission power of the terminal device in the further cell.
The method of claim 10, further comprising:

determining first and second priorities of first and second channels used by the terminal device in the cell based on types of the first and second charmels; and

in response to the first priority being higher than the second priority, reducing a transmission power of the terminal device on the second channel.
The method of claim 10, wherein the second information is transmitted in a power headroom report (PHR) .
A method, comprising:

transmitting, at a network device and to a terminal device, first information of a required transmission power, the required transmission power being a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device;

receiving, from the terminal device, second information comprising an indication of power reduction for the uplink transmission in the cell; and

performing communication with the terminal device based on the indication.
The method of claim 15, wherein the second information further comprises at least one of:

an amount of the power reduction, and

a cause for the power reduction.
The method of claim 15, wherein performing communication with the terminal device comprises:

reducing physical uplink shared channel (PUSCH) allocation bandwidth for the terminal device.
The method of claim 15, wherein the second information is received in a power headroom report (PHR) .
A computer readable medium storing instructions thereon, the instructions, when executed by at least one processing unit of a machine, causing the machine to perform the method according to any one of claims 10-14.
A computer readable medium storing instructions thereon, the instructions, when executed by at least one processing unit of a machine, causing the machine to perform the method according to any one of claims 15-18.
An apparatus, comprising:

means for receiving, at a terminal device and from a network device, first information of a required transmission power, the required transmission power being a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device;

means for comparing the required transmission power with a maximum transmission power of the terminal device; and

means for in response to the required transmission power exceeding the maximum transmission power, transmitting, to the network device, second information comprising an indication of power reduction for the uplink transmission in the cell.
An apparatus, comprising:

means for transmitting, at a network device and to a terminal device, first information of a required transmission power, the required transmission power being a transmission power required by the network device for the terminal device to perform uplink transmission in a cell managed by the network device;

means for receiving, from the terminal device, second information comprising an indication of power reduction for the uplink transmission in the cell; and

means for performing communication with the terminal device based on the indication.