WO2016179831A1

WO2016179831A1 - Methods and apparatuses for data transmission and receiving in a wireless communication system

Info

Publication number: WO2016179831A1
Application number: PCT/CN2015/078960
Authority: WO
Inventors: Hongmei Liu; Lei Jiang; Chuangxin JIANG; Yukai GAO; Zhennian SUN; Gang Wang
Original assignee: Nec Corporation
Priority date: 2015-05-14
Filing date: 2015-05-14
Publication date: 2016-11-17

Abstract

Embodiments of the present disclosure relate to a method and apparatus of data transmission in a wireless communication system and a method and apparatus of receiving data in a wireless communication system. The method of data transmission comprises detecting a clear channel on an unlicensed carrier for a data transmission; obtaining available time of the detected clear channel for the data transmission; and determining a scheduling mode for the data transmission based on the available time. With embodiments of the present disclosure, it provides a new solution for data transmission and receiving, in which the scheduling mode for the data transmission will be selected based on the available time of the clear channel on the unlicensed carrier. In such a way, it is possible to use licensed and unlicensed resource to full advantage and achieve an improved system performance.

Description

METHODS AND APPARATUSES FOR DATA TRANSMISSION AND RECEIVING IN A WIRELESS COMMUNICATION SYSTEM

FIELD OF THE INVENTION

Embodiments of the present disclosure generally relate to wireless communication techniques and more particularly relate to a method and apparatus for data transmission in a wireless communication system and a method and apparatus for data receiving in a wireless communication.

BACKGROUND OF THE INVENTION

With the constant increase of wireless data services， licensed carrier resource is limited and hard to cope with the constantly increasing data traffic. Thus， it is proposed to use unlicensed carrier resource for data transmission， which could provide a large amount of frequency resources in a cost effective way.

Recently， the 3rd Generation Partnership Project (3GPP) organization had started standardization on Licensed-Assisted Access， which introduces the data transmission from the licensed carrier resource to the unlicensed carrier resource on small cells to deliver a data speed boost to terminal devices. For data transmission on the unlicensed carrier， it shall perform a Listen Before Talk (LBT) operation to detect whether the channel is idle. The transmission on the unlicensed carrier can only be performed when the LBT result shows that the channel is idle； otherwise the transmission will not be performed on the unlicensed carrier.

Cross carrier scheduling (CCS) is a scheduling solution in which the control information for data transmission is transmitted on the licensed carrier which is more reliable than the unlicensed carrier， while the data information is transmitted on the unlicensed carrier. In such a way， the control information can be protected very well by locating it at the more reliable licensed carrier.

US patent application publication No. US2015/0098437A discloses a solution for enabling wireless communications using subframe structure having different subframe durations. In the proposed solution， licensed carrier and unlicensed carrier have a first subframe duration and a second subframe duration respectively； the cross carrier scheduling from licensed carrier to unlicensed carrier is performed； the control information is detected on the licensed carrier and the data information on the unlicensed carrier is decoded.

US patent application publication No. 2015/0103777A discloses a solution for downlink control management in an unlicensed or shared spectrum. In this proposed solution， an evolved Node B (eNB) first performs a clear channel access CCA on the unlicensed carrier， indicates the CCA result to user equipment (UE) by licensed carrier transmission and communicates with the UE on unlicensed carrier if the CCA result is idle.

A unit of scheduling in the long term evolution (LTE) system is per subframe， while a CCA or LBT duration is about 20us， which means LBT operations can happen many times in a single subframe. However， if the channel on the unlicensed carrier is idle after the control information end boundary， the CCS cannot be performed. The reason lies in that， for the CSS， the control information for data information transmission on the unlicensed carrier shall be decided before the data information transmission but after the control information end boundary， the control information cannot be transmitted.

SUMMARY OF THE INVENTION

In the present disclosure， there is provided a new solution for downlink data transmission in a wireless communication system， which is quite different from those in the prior art.

According to a first aspect of the present disclosure， there is provided a method for data transmission in a wireless communication system. The method may comprise： detecting a clear channel on an unlicensed carrier for a data transmission； obtaining available time of the detected clear channel for the data transmission； and determining a scheduling mode for the data transmission based on the available time.

In an embodiment of the present disclosure， the scheduling mode may be determined as a cross carrier scheduling if the available time is before a start boundary of a data channel in a subframe to be scheduled.

In a further embodiment of the present disclosure， control information for the data transmission may be transmitted in reserved control resource in the subframe.

In a still further embodiment of the present disclosure， the control information for the data transmission may be transmitted in the reserved control resource only if the available time is after a start boundary of a control channel in the subframe.

In a yet further embodiment of the present disclosure， the reserved control resource may be unused time resource in the subframe if the available time is before an end boundary of a control channel in the subframe.

In another embodiment of the present disclosure， the unused time resource in the subframe may be indicated to a terminal device by a Physical Control Format Indicator Channel (PCFICH) indication and a high layer signaling indicating the start boundary of the data channel.

In a further embodiment of the present disclosure， the unused time resource in the subframe may be scheduled only on a part of system bandwidth.

In a still further embodiment of the present disclosure， the reserved control resource may be unused frequency resource in an enhanced control channel in the subframe， which is indicated to a terminal device through a signaling.

In a yet further embodiment of the present disclosure， the scheduling mode may be determined as a regular cross carrier scheduling if the available time is before a start boundary of the subframe.

In another embodiment of the present disclosure， the scheduling mode may be determined as a self-scheduling if the available time is after a start boundary of a data channel in a subframe to be scheduled.

In a second aspect of the present disclosure， there is provided a method of receiving data in a wireless communication system. The method comprises detecting control information on predetermined reserved control resource on a licensed carrier， wherein the control information can be contained on the predetermined reserved control resource； and decoding， based on the detected control information， data information on a corresponding unlicensed carrier.

In a third aspect of the present disclosure， there is also provided an apparatus for data transmission in a wireless communication system. The apparatus comprises a channel detection module， configured to detect a clear channel on an unlicensed carrier for a data transmission a time obtainment module， configured to obtain available time of the detected clear channel for the data transmission； and a mode determination module， configured to determine a scheduling mode for the data transmission based on the available time.

In a fourth aspect of the present disclosure， there is provided an apparatus of receiving data in a wireless communication system. The apparatus comprises an information detection module， configured to detect control information on predetermined reserved control resource on a licensed carrier， wherein the control information can be contained on the predetermined reserved control resource； and an information decoding module， configured to decode， based on the detected control information， data information on a corresponding unlicensed carrier.

According to a fifth aspect of the present disclosure， there is also provided a computer-readable storage media with computer program code embodied thereon， the computer program code configured to， when executed， cause an apparatus to perform actions in the method according to any embodiment in the first aspect.

According to a sixth aspect of the present disclosure， there is also provided a computer-readable storage media with computer program code embodied thereon， the computer program code configured to， when executed， cause an apparatus to perform actions in the method according to any embodiment in the second aspect.

According to a seventh aspect of the present disclosure， there is provided a computer program product comprising a computer-readable storage media according to the fifth aspect.

According to an eighth aspect of the present disclosure， there is provided a computer program product comprising a computer-readable storage media according to the sixth aspect.

With embodiments of the present disclosure， it provides a new solution for data transmission and receiving， in which the scheduling mode for the data transmission will be selected based on the available time of the clear channel on the unlicensed carrier. In such a way， it is possible to use licensed and unlicensed resource to full advantage and achieve an improved system performance.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present disclosure will become more apparent through detailed explanation on the embodiments as illustrated in the embodiments with reference to the accompanying drawings， throughout which like reference numbers represent same or similar components and wherein：

Fig. 1 schematically illustrates an example LBT operation， wherein the channel on an unlicensed carrier is available after the control information end boundary；

Fig. 2 schematically illustrates a flow chart of a method of data transmission in a wireless communication system according to an embodiment of the present disclosure；

Figs. 3A to 3C schematically illustrates different cases of channel available time according to different embodiments of the present disclosure；

Fig. 4 schematically illustrates exemplary scheduling modes in different cases of channel available time according to an embodiment of the present disclosure；

Fig. 5 schematically illustrates an example of reserved control resource according to an embodiment of the present disclosure；

Fig. 6 schematically illustrates another example of reserved control resource according to an embodiment of the present disclosure；

Fig. 7 schematically illustrates a flow chart of a method of receiving data in a wireless communication system according to an embodiment of the present disclosure；

Fig. 8 schematically illustrates different manners of receiving data at a terminal device according to an embodiment of the present disclosure；

Fig. 9 schematically illustrates a block diagram of an apparatus for data transmission in a wireless communication system according to an embodiment of the present disclosure； and

Fig. 10 schematically illustrates a block diagram of an apparatus for receiving data in a wireless communication system according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter， the solution as provided in the present disclosure will be described in details through embodiments with reference to the accompanying drawings. It should be appreciated that these embodiments are presented only to enable those skilled in the art to better understand and implement the present disclosure， not intended to limit the scope of the present disclosure in any manner.

In the accompanying drawings， various embodiments of the present disclosure are illustrated in block diagrams， flow charts and other diagrams. Each block in the flowcharts or blocks may represent a module， a program， or a part of code， which contains one or more executable instructions for performing specified logic functions， and in the present disclosure， a dispensable block is illustrated in a dotted line. Besides， although these blocks are illustrated in particular sequences for performing the steps of the methods， as a matter of fact， they may not necessarily be performed strictly according to the illustrated sequence. For example， they might be performed in reverse sequence or simultaneously， which is dependent on natures of respective operations. It should also be noted that block diagrams and/or each block in the flowcharts and a combination of thereof may be implemented by a dedicated hardware-based system for performing specified functions/operations or by a combination of dedicated hardware and computer instructions.

Generally， all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field， unless explicitly defined otherwise herein. All references to ″a/an/the/said [element， device， component， means， step， etc] ″ are to be interpreted openly as referring to at least one instance of said element， device， component， means， unit， step， etc.， without excluding a plurality of such devices， components， means， units， steps， etc.， unless explicitly stated otherwise. Besides， the indefinite article “a/an” as used herein does not exclude a plurality of such steps， units， modules， devices， and objects， and etc.

Additionally， in a context of the present disclosure， a user equipment (UE) may refer to a terminal， a Mobile Terminal (MT) ， a Subscriber Station (SS) ， a Portable Subscriber Station (PSS) ， Mobile Station (MS) ， or an Access Terminal (AT) ， and some or all of the functions of the UE， the terminal， the MT， the SS， the PSS， the MS，or the AT may be included. Furthermore， in the context of the present disclosure， the term “BS” may represent， e.g.， a node B (NodeB or NB) ， an evolved NodeB (eNodeB or eNB) ， a radio header (RH) ， a remote radio head (RRH) ， a relay， or a low power node such as a femto， a pico， and so on.

As mentioned hereinabove， if the cross carrier scheduling is used for a data transmission on the unlicensed carrier， control information for the data transmission shall be decided prior to the data transmission； otherwise the cross carrier scheduling cannot be used. Only for a purpose of illustration， Fig. 1 illustrates an example LBT operation， wherein the channel is available after the control information end boundary. As illustrated in Fig. 1， the upper graph illustrates subframes used in Primary cell (Pcell) ， i.e.， a licensed carrier； and the lower graph illustrates subframes used in Secondary cell (Scell) ， i.e.， an unlicensed carrier. An LBT is performed on the unlicensed carrier and ends after the control channel end boundary， i.e.， the end boundary of Physical Downlink Control Channel (PDCCH) . The LBT’s result shows that the channel is available. At this time point， the control information cannot be transmitted in PDCCH because the PDCCH is already transmitted and it is also impossible to transmit the control information on the evolved PDCCH (ePDCCH) as well， since the ePDCCH shall occupy the whole subframe duration. Thus， in such a case， it cannot use the unlicensed carrier for data transmission.

In view of this， in the present disclosure， there is provided a new solution of transmitting data and receiving data in a wireless communication system， which will be described in detailed with reference to the accompany drawings as provided therein.

Fig. 2 schematically illustrates a flow chart of a method of data transmission in a wireless communication system according to an embodiment of the present disclosure. As illustrated in Fig. 2， first as step S201， a detection of a clear channel on an unlicensed carrier for a data transmission is performed. In order to use the unlicensed carrier for data transmission， it shall first determine whether there is a clear channel available. Thus， it may perform an LBT operation. The LBT is well-known in the art and thus will not be elaborated herein for a purpose of simplification.

Then at step S202， available time of the detected clear channel for the data transmission is obtained. If a clear channel is detected at step S201， which means there is an idle channel， it may determine the time from which the channel is available. Or the time that LBT ends is obtained as the available time of the detected clear channel.

Afterwards， at step S203， a scheduling mode for the data transmission can be determined based on the available time. In the present disclosure， it is to adopt different scheduling modes for different available time. That is to say， it is proposed to select suitable scheduling modes for different available time respectively. In embodiment of the present disclosure， the available time can be divided into several different cases. Next， for illustration purposes， reference will be made to Figs. 3A through Fig. 3C to describe example cases of the available time in details.

Reference is first made to Fig. 3A， in which case A is illustrated. In the case A， the LBT is finished before a subframe to be scheduled starts and the LBT result is “idle” . In other word， the clear channel is available before the start boundary of a subframe to be scheduled or the start boundary of the control channel (PDCCH for example) of this subframe. In such a case， it is clear that the available time of the clear channel on the unlicensed carrier is also before a start boundary of the data channel (a physical downlink sharing channel (PDSCH) for example) . Fig. 3B illustrates another case， i.e.， Case B， in which the LBT is finished after the start boundary of the subframe but before the start boundary of the data channel (PDSCH for example) in the subframe to be scheduled and the LBT result is idle. In this case， the PDCCH is transmitting. Fig. 3C illustrates a further case， in which the LBT is performed after the PDSCH/ePDCCH starts， i.e.， after the start boundary of the data channel， which means that the PDSCH/ePDCCH is transmitting.

For different cases of the available time， different scheduling modes can be adopted， which will be described herein wither reference to Fig. 4. As illustrated in Fig. 4， first it is determined whether the LBT end before the start boundary of the data channel (PDSCH for example) ， and if yes (case A and case B in Fig. 3) ， the scheduling mode can be determined as a cross carrier scheduling. The cross carrier scheduling herein means a scheduling solution that transmits the control information and the data information using two different carriers. For example， it may transmit the control information on the licensed carrier and transmit the data information on the unlicensed carrier. In such a case， it may use reserved control resource， which is behind the PDCCH， and used to transmit control information for the data transmission. The reserved control resource herein refers to specific resource in the subframe reserved for transmitting the control information for the data transmission on unlicensed carrier. In embodiments of the present disclosure， there are provided different kinds of reserved control resource， which can be used as the resource for the control information transmission in such a case. The example arrangements of reserved control resource will be detailed with reference to Figs. 5 and 6 and will be not elaborated herein.

In an embodiment of the present disclosure， the control information for the data transmission can be transmitted in the reserved control resource only if the available time is after a start boundary of a control channel in the subframe to be scheduled (case B in Fig. 3) . When the available time is before a start boundary of the subframe (case A in Fig. 3) ， the scheduling mode can be determined as a regular cross carrier scheduling， in which the control information will be transmitted using PDCCH.

It can be appreciated that if the available time is after a start boundary of a control channel in the subframe to be scheduled (case B) ， the PDCCH cannot be used because it is transmitting. In this case B， it is possible to determine the scheduling mode as the cross carrier scheduling with the reserved control resource to use reserved control resource to transmit the control information instead of using the PDDCH. On the other hand， if the available time is before a start boundary of the subframe to be scheduled (case A) ， that means the subframe does not start yet and it is possible to decide the control information before data transmission on the unlicensed carrier and transmit the control information on the PDCCH. Thus， in such a case， the scheduling mode can be determined as the regular cross carrier scheduling and the PDCCH is used to transmit the control information. However， it can also be appreciated that in such a case， it is also possible to use reserved control resource for the control information transmission although the PDCCH can be used to transmit the control information. That means， for case A， there are two choices about how to transmit the control information， i.e.， using the PDCCH or using the reserved control resource.

Besides， as illustrated in Fig. 4， if the available time is after a start boundary of a data channel in a subframe to be scheduled (case C) ， the scheduling mode is determined as a self-scheduling. In case C， the PDSCH was transmitted and the ePDCCH is transmitting， there is no channel to perform cross carrier scheduling in this subframe. Therefore， it can perform a self-scheduling， which means both the control information and the data information are transmitted on the unlicensed carrier. As an alternative option， it is possible to wait until the next subframe to use the PDCCH or reserved control resource in the next subframe to transmit the control information.

Next， reference is made to Figs. 5 and 6 to describe different reserved control designs. Fig. 5 illustrates an example of reserved control resource according to an embodiment of the present disclosure， which is unused time resource in the subframe. In Fig. 5， during the whole subframe duration， there are contained symbols for PDCCH (denoted with blocks filled with dots) and symbols for the PDSCH (denoted with blocks filled with white) . Usually， between the end boundary of the PDCCH and the start boundary of the PDSCH， there is an unused symbol (denoted with block filled with slashes) ， which can be used as reserved control resource. As illustrated in Fig. 5， symbol 2 is unused time resource in the subframe. Physical resource blocks (PRBs) at symbol 2 can be used to carry the control information of the data information transmission on the unlicensed carrier and thus the whole symbol 2 can be occupied. Particularly， the unused time resource in the subframe can be scheduled only on a part of system bandwidth， which means only some specific PRBs at symbol 2 will be used for the control information transmission instead of occupying the whole system bandwidth. In such way， it is possible to leave more PRB for other purposes. While for legacy UEs， since they cannot interpret the PCFICH and the higher signaling indicating the reserved control resource， the eNB will not schedule the reserved resource.

This reserved control resource can be indicated by a specific singling to the terminal device so as to inform the terminal device of the position of the unused symbol. However， it can be indicated by other different ways as well. For example， in the current system， a Physical Control Format Indicator Channel (PCFICH) is used to indicate the legacy PDCCH symbols， from which it can know the symbols for the PDCCH in the subframe. For example， it may indicate the first two symbols， i.e. symbols 0 and 1 are used for the PDCCH as illustrated in Fig. 5. At the same time， a higher signaling is used to indicate the PDSCH starting point， by means of which it is possible to know the start boundary of the PDSCH， for example symbol 3 as shown in Fig. 5. In such a way， a terminal device may interpret the PCFICH and the higher layer signaling and learn that the reserved control resource is symbol 2. Besides， if specific PRBs are used， it can use a higher layer signaling to configure these specific PRBs. By this means， the terminal device could obtain the control information on specific PRBs in the symbol 2.

Fig. 6 illustrates another example of reserved control resource according to an embodiment of the present disclosure which is unused frequency resource in the subframe to be scheduled. The ePDCCH is another channel for transmitting control information， which occupies the same symbols as the PDSCH in the time domain and a few PRBs in the frequency domain. In embodiments of the present disclosure， a specific PRB can be reserved for the control information transmission. The specific PRB is a special frequency resource reserved for control information for data transmission on unlicensed carrier. By means of this specific PRB on symbols lasting during the PDSCH， it is possible to transmit the control information for the data information transmission on the unlicensed carrier. This specific PRB can be indicated to the terminal device through an explicit signaling.

By means of the example reserved control resource as illustrated in Figs. 5 and 6， the UE can obtain the control information and decode the data information on the unlicensed carrier. However， it should be noted that these are illustrated for a purpose of illustration and the present disclosure is not limited thereto， it is possible to make modifications to arrangements of the reserved control resource as provided herein.

With embodiments of the present disclosure， the scheduling mode for the data transmission will be selected based on the available time of the clear channel on the unlicensed carrier. In other words， for different available time， different scheduling mode will be adopted. Particularly， for case A， regular cross carrier scheduling can be performed in which the control information is transmitted using the PDCCH； for case B， in which the cross carrier scheduling cannot be performed according to the existing solution， the control information can be transmitted on reserved control resource； for case C， the self-scheduling may be performed， in which the control information is transmitted on the unlicensed carrier. In such a way， it is possible to use licensed and unlicensed resource to full advantage and achieve an improved system performance.

Hereinafter， data receiving operations at a terminal device will be described in detail with reference to Fig. 7， which schematically illustrates a flow chart of a method of receiving data in a wireless communication system according to an embodiment of the present disclosure. As illustrated in Fig. 7， first at step S710， control information is detected on predetermined reserved control resource on a licensed carrier. The predetermined reserved control resource is reserved resource for the control information transmission. It could be default reserved control resource which is known by other the eNB or is indicated by the eNB to the terminal device by control information indication message， such as specific signaling.

The reserved control resource can be for example resource unused for any other purpose in the subframe. As an example， the reserved control resource unused time resource in this subframe， which could be indicated by a Physical Control Format Indicator Channel (PCFICH) indication and a high layer signaling indicating a start boundary of a data channel. As another choice， it can use a specific signaling to indicate the position of the reserved control resource. The unused time resource can be scheduled only on a part of system bandwidth. In such way， it is possible to leave more PRBs for other purposes. Alternatively， the reserved control resource can also be unused frequency resource in an enhanced control channel. In such a case， it may be indicated to the UE through a signaling.

In an embodiment of the present disclosure， the terminal device may first detect the control information on a control channel of the licensed carrier as step S705. That is to say， the UE first detects the control information on the PDCCH. In a case that no control information is found (N in step S707) ， the step S710 will be performed； otherwise， the method may proceed with step S720.

Further， it may determine after step S710 whether the control information is found on the reserved control resource at step S715. If the control information is detected， the method proceeds with step S720； otherwise， the UE detects the control information on an unlicensed carrier.

Next， at step 720， data information on a corresponding unlicensed carrier is decoded based on the detected control information. Once the control information is detected， the control information can be used to obtain the data information on the unlicensed carrier and decode the data information to obtain the transmitted data information.

For an illustration purpose， Fig. 8 illustrates different manners of receiving data at a terminal device according to an embodiment of the present disclosure. For case A， the LBT ends before the start boundary of the subframe and the LBT result shows that the channel is idle. In case A， the scheduling mode is determined as the regular cross carrier scheduling， and the UE monitors the PDCCH on the Pcell and obtain the control information from the PDCCH， as illustrated in Fig. 8. For case B， the LBT ends after the start boundary of the subframe but before the start boundary of the PDSCH and the LBT result shows that the channel is idle. In case B， the scheduling mode is determined as the cross carrier scheduling with the reserved control resource and thus the UE monitors the control resource on Pcell including the reserved control resource. The information can be obtained from the reserved time resource between the end boundary of the PDCCH and the start boundary of the PDSCH or from specific PRB on the ePDCCH. For case C， the LBT ends after the start boundary of the PDSCH and the LBT result shows that the channel is idle. In case C， the scheduling mode is determined as self-scheduling and the UE monitors the PDCCH on Scell. The control information will be obtained from the control channel on the Scell.

Thus， the UE could obtain the control information and decoding the data information transmitted on the unlicensed carrier. The licensed and unlicensed resource can be used to full advantage and an improved system performance can be achieved.

Besides， in the present disclosure， there are also provided apparatuses for data transmission and receiving in a wireless communication system， which will be described next with reference to Figs. 9 and 10.

Reference is made to Fig. 9， which schematically illustrates a block diagram of an apparatus for data transmission in a wireless communication system according to an embodiment of the present disclosure. As illustrated in Fig. 9， apparatus 900 comprises a channel detection module 910， a time obtainment module 920 and a mode determination module 930. The channel detection module 910 is configured to detect a clear channel on an unlicensed carrier for a data transmission. The time obtainment module 920 is configured to obtain available time of the detected clear channel for the data transmission. The mode determination module 930 is configured to determine a scheduling mode for the data transmission based on the available time.

In an embodiment of the present disclosure， the scheduling mode may be determined as a cross carrier scheduling if the available time is before a start boundary of a data channel in a subframe to be scheduled. Particularly， control information for the data transmission may be transmitted in reserved control resource in the subframe. In another embodiment of the present disclosure， the control information for the data transmission may be transmitted in the reserved control resource only if the available time is after a start boundary of a control channel in the subframe. Particularly， the reserved control resource may be unused time resource in the subframe if the available time is before an end boundary of the control channel. In such a case， the unused time resource in the subframe is indicated to a terminal device by a Physical Control Format Indicator Channel (PCFICH) indication and a high layer signaling indicating the start boundary of the data channel. Moreover， advantageously， the unused time resource in the subframe can be scheduled only on a part of system bandwidth. In a further embodiment of the present disclosure， the reserved control resource can be unused frequency resource in an enhanced control channel in the subframe， which is indicated to terminal device through a signaling.

In another embodiment of the present disclosure， the scheduling mode can be determined as a regular cross carrier scheduling if the available time is before a start boundary of the subframe. On the other hand， ifthe available time is after a start boundary of a data channel in a subframe to be scheduled， the scheduling mode can be determined as a self-scheduling. Or alternatively， the eNB can wait until the next subframe so as to transmit the control information on the PDCCH or the reserved control resource

Reference is further made to Fig. 10， which schematically illustrates a block diagram of an apparatus for receiving data in a wireless communication system according to an embodiment of the present disclosure. As illustrated in Fig. 10， apparatus 1000 comprises an information detection module 1010 and an information decoding module 1020. The information detection module 1010 can be configured to detect control information on predetermined reserved control resource on a licensed carrier. The predetermined reserved control resource is resource which could be used to carry the control information for data transmission on the unlicensed carrier， or in other word， the control information could be contained on the predetermined reserved control resource. The information decoding module 1020 can be configured to decode， based on the detected control information， data information on a corresponding unlicensed carrier.

In an embodiment of the present disclosure， the reserved control resource is unused time resource in a subframe. The unused time resource can be indicated for example by a Physical Control Format Indicator Channel (PCFICH) indication and a high layer signaling indicating a start boundary of a data channel. Or alternatively， the unused time resource can be indicated by a dedicated signaling. Moreover， the unused time resource is particularly scheduled only on a part of system bandwidth. By this means， it is possible to meet the requirement of control information transmission and at the same time leave more resource for other purposes.

In another embodiment of the present disclosure， the reserved control resource is unused frequency resource in an enhanced control channel， which is indicated through a signaling.

The information detection module 1010 can be further configured to detect the control information on a control channel of the licensed carrier. In such a case， the information detection module 1010 is configured to detect the control information on the predetermined reserved control resource in response to failing to detect the control information on the control channel of the licensed carrier.

In a further embodiment of the present disclosure， the information detection module 1010 can be further configured to detect the control information on an unlicensed carrier in response to failing to detect the control information on the predetermined reserved control resource.

Hereinbefore， the apparatuses 900 and 1000 are described with reference to Figs. 9 and 10. It is noted that the apparatuses 900 and 1000 may be configured to implement functionalities as described with reference to Figs. 1 to 8. Therefore， for details about the operations of modules in these apparatuses， one may refer to those descriptions made with respect to the respective steps of the methods with reference to Figs. 1 to 8.

It is further noted that the components of the apparatuses 900 and 1000 may be embodied in hardware， software， firmware， and/or any combination thereof. For example， the components of apparatuses 900 and 1000 may be respectively implemented by a circuit， a processor or any other appropriate selection device. Those skilled in the art will appreciate that the aforesaid examples are only for illustration not limitation.

In some embodiment of the present disclosure， apparatuses 900 and 1000 may comprise at least one processor. The at least one processor suitable for use with embodiments of the present disclosure may include， by way of example， both general and special purpose processors already known or developed in the future. Apparatuses 900 and 1000 may further comprise at least one memory. The at least one memory may include， for example， semiconductor memory devices， e.g.， RAM， ROM， EPROM， EEPROM， and flash memory devices. The at least one memory may be used to store program of computer executable instructions. The program can be written in any high-level and/or low-level compliable or interpretable programming languages. In accordance with embodiments， the computer executable instructions may be configured， with the at least one processor， to cause apparatuses 900 and 1000 to at least perform operations according to the method as discussed with reference to Figs. 1 to 8 respectively.

It shall be appreciated that the above-mentioned solutions can be used in both an initial data transmission and a data retransmission. That is to say， either of the initial data transmission and the data retransmission can be cross scheduled. In fact， the data retransmission can also be performed on a different carrier from the initial data transmission， and different data retransmissions can be performed on different carriers as well， which may be called as cross carrier Hybrid Automatic Repeat reQuest (HARQ) . On the other hand， the terminal device shall have the capability of the cross carrier HARQ， which means if the terminal device does not have the capability， the cross carrier HARQ cannot be performed between the terminal device and eNB. In such case， if the terminal device can support this feature， i.e. receiving different transmissions for same data on different carriers， it could use a specific signaling to inform the eNB.

Accordingly， in another aspect of the present disclosure， there is further provided a method for data transmission in a wireless communication. The method comprises performing a first transmission for data on a first carrier， and performing a second transmission for the data on a second first carrier which is different from the first carrier. In an embodiment of the present disclosure， the method is performed in response to a signaling from a terminal device to which the data is to be transmitted， wherein the signaling indicates that the terminal device supports different transmissions for the data on different carriers.

In a further aspect of the present disclosure， there is provided a method of data receiving in a wireless communication. The method comprises transmitting a signaling to a serving node to indicate the supporting of different transmissions for a data on different carriers； receiving a data in a first transmission on a first carrier and receiving the data in a second transmission on a second carrier which is different from the first carrier.

In a yet further aspect of the present disclosure， there is further provided an apparatus for data transmission in a wireless communication. The apparatus comprises a data transmission module， configured to perform a first transmission for data on a first carrier， and perform a second transmission for the data on a second carrier which is different from the first carrier. In an embodiment of the present disclosure， the transmission module is configured to perform the transmission in response to a signaling from a terminal device to which the data is to be transmitted， wherein the signaling indicates that the terminal device supports different transmissions for the data on different carriers.

In a further aspect of the present disclosure， there is provided an apparatus of data receiving in a wireless communication. The apparatus comprises a signaling transmission module， configured to transmit a signaling to a serving node to indicate the supporting of different transmissions for a data on different carriers； a data receiving module， configured to receive a data in a first transmission on a first carrier and receive the data in a second transmission on a second carrier which is different from the first carrier.

In addition， based on the above description， the skilled in the art would appreciate that the present disclosure may be embodied in an apparatus， a method， or a computer program product. In general， the various exemplary embodiments may be implemented in hardware or special purpose circuits， software， logic or any combination thereof. For example， some aspects 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 disclosure is not limited thereto. While various aspects of the exemplary embodiments of this disclosure may be illustrated and described as block diagrams， flowcharts， 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 various blocks shown in the companying drawings may be viewed as method steps， and/or as operations that result from operation of computer program code， and/or as a plurality of coupled logic circuit elements constructed to carry out the associated function (s) . At least some aspects of the exemplary embodiments of the disclosures may be practiced in various components such as integrated circuit chips and modules， and that the exemplary embodiments of this disclosure may be realized in an apparatus that is embodied as an integrated circuit， FPGA or ASIC that is configurable to operate in accordance with the exemplary embodiments of the present disclosure.

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 purposes of limitation.

Claims

A method of data transmission in a wireless communication system， comprising：

detecting a clear channel on an unlicensed carrier for a data transmission；

obtaining available time of the detected clear channel for the data transmission； and

determining a scheduling mode for the data transmission based on the available time.
The method of Claim 1， wherein the scheduling mode is determined as a cross carrier scheduling if the available time is before a start boundary of a data channel in a subframe to be scheduled.
The method of Claim 2， wherein control information for the data transmission is transmitted in reserved control resource in the subframe.
The method of Claim 3， wherein the control information for the data transmission is transmitted in the reserved control resource only if the available time is after a start boundary of a control channel in the subframe.
The method of Claim 3， wherein the reserved control resource is unused time resource in the subframe if the available time is before an end boundary of a control channel in the subframe.
The method of Claim 5， wherein the unused time resource in the subframe is indicated to a terminal device by a Physical Control Format Indicator Channel (PCFICH) indication and a high layer signaling indicating the start boundary of the data channel.
The method of Claim 5， wherein the unused time resource in the subframe is scheduled only on a part of system bandwidth.
The method of Claim 3， wherein the reserved control resource is unused frequency resource in an enhanced control channel in the subframe， which is indicated to a terminal device through a signaling.
The method of Claim 2， wherein the scheduling mode is determined as a regular cross carrier scheduling ifthe available time is before a start boundary of the subframe.
The method of Claim 1， wherein the scheduling mode is determined as a self-scheduling if the available time is after a start boundary of a data channel in a subframe to be scheduled.
A method of receiving data in a wireless communication system， comprising：

detecting control information on predetermined reserved control resource on a licensed carrier， wherein the control information can be contained on the predetermined reserved control resource； and

decoding， based on the detected control information， data information on a corresponding unlicensed carrier.
The method of Claim 11， wherein the reserved control resource is unused time resource in a subframe.
The method of Claim 12， wherein the unused time resource is indicated by a Physical Control Format Indicator Channel (PCFICH) indication and a high layer signaling indicating a start boundary of a data channel.
The method of Claim 13， wherein the unused time resource is scheduled only on a part of system bandwidth.
The method of Claim 11， wherein the reserved control resource is unused frequency resource in an enhanced control channel， which is indicated through a signaling.
The method of Claim 11， further comprising：

detecting the control information on a control channel of the licensed carrier，

wherein the detecting the control information on the predetermined reserved control resource is performed in response to failing to detect the control information on the control channel of the licensed carrier.
The method according to Claim 11， further comprising：

detecting the control information on an unlicensed carrier， in response to failing to detect the control information on the predetermined reserved control resource.
An apparatus for data transmission in a wireless communication system， comprising：

a channel detection module， configured to detect a clear channel on an unlicensed carrier for a data transmission；

a time obtainment module， configured to obtain available time of the detected clear channel for the data transmission； and

a mode determination module， configured to determine a scheduling mode for the data transmission based on the available time.
The apparatus of Claim 18， wherein the scheduling mode is determined as a cross carrier scheduling if the available time is before a start boundary of a data channel in a subframe to be scheduled.
The apparatus of Claim 19， wherein control information for the data transmission is transmitted in reserved control resource in the subframe.
The apparatus of Claim 20， wherein the control information for the data transmission is transmitted in the reserved control resource only if the available time is after a start boundary of a control channel in the subframe.
The apparatus of Claim 20， wherein the reserved control resource is unused time resource in the subframe if the available time is before an end boundary of a control channel in the subframe.
The apparatus of Claim 22， wherein the unused time resource in the subframe is indicated to a terminal device by a Physical Control Format Indicator Channel (PCFICH) indication and a high layer signaling indicating the start boundary of the data channel.
The apparatus of Claim 22， wherein the unused time resource in the subframe is scheduled only on a part of system bandwidth.
The apparatus of Claim 20， wherein the reserved control resource is unused frequency resource in an enhanced control channel in the subframe， which is indicated to terminal device through a signaling.
The apparatus of Claim 19， wherein the scheduling mode is determined as a regular cross carrier scheduling if the available time is before a start boundary of the subframe.
The apparatus of Claim 18， wherein the scheduling mode is determined as a self-scheduling if the available time is after a start boundary of a data channel in a subframe to be scheduled.
An apparatus for receiving data in a wireless communication system， comprising：

an information detection module， configured to detect control information on predetermined reserved control resource on a licensed carrier， wherein the control information can be contained on the predetermined reserved control resource； and

an information decoding module， configured to decode， based on the detected control information， data information on a corresponding unlicensed carrier.
The apparatus of Claim 28， wherein the reserved control resource is unused time resource in a subframe.
The apparatus of Claim 29， wherein the unused time resource is indicated by a Physical Control Format Indicator Channel (PCFICH) indication and a high layer signaling indicating a start boundary of a data channel.
The apparatus of Claim 30， wherein the unused time resource is scheduled only on a part of system bandwidth.
The apparatus of Claim 28， wherein the reserved control resource is unused frequency resource in an enhanced control channel， which is indicated through a signaling.
The apparatus of Claim 28， wherein the information detection module is further configured to detect the control information on a control channel of the licensed carrier， and wherein the information detection module is configured to detect the control information on the predetermined reserved control resource in response to failing to detect the control information on the control channel of the licensed carrier.
The apparatus of Claim 28， wherein the information detection module is further configured to detect the control information on an unlicensed carrier in response to failing to detect the control information on the predetermined reserved control resource.