WO2018115967A1

WO2018115967A1 - Method of autonomous uplink signal transmission and corresponding terminal device and network device

Info

Publication number: WO2018115967A1
Application number: PCT/IB2017/001695
Authority: WO
Inventors: Tao Tao; Jianguo Liu; Zhe LUO; Gang Shen; Yan Meng
Original assignee: Alcatel Lucent
Priority date: 2016-12-23
Filing date: 2017-12-20
Publication date: 2018-06-28
Also published as: CN108243497A; CN108243497B

Abstract

Embodiments of the present disclosure relate to a method of autonomous uplink signal transmission and a corresponding terminal device and network device. For example, at a side of a terminal device in a communication network, an indication of a resource configuration is received from a network device for transmitting an autonomous uplink signal to the network device, and a sub-frame is determined based on the received indication of the resource configuration for transmitting the autonomous uplink signal. Then, the terminal device transmits the autonomous uplink signal to the network device in the determined sub-frame. The corresponding method implemented at the network device as well as the terminal device and network device capable of implementing the above methods are also disclosed.

Description

METHOD OF AUTONOMOUS UPLINK SIGNAL TRANSMISSION AND CORRESPONDING TERMINAL DEVICE AND NETWORK

DEVICE

TECHNOLOGY

[0001] Embodiments of the present disclosure generally relate to communication technology, and more specifically, to a method for autonomous uplink signal transmission and a corresponding terminal device and network device.

BACKGROUND

[0002] In a current cellular communication system, such as an enhanced Licensed- Assisted Access (eLAA) system or a MulteFire (MF) system, unlicensed spectrums have become a beneficial supplement for licensed spectrums to meet increasing traffic needs in the network. When the cellular system, such as the eLAA or MF system, coexists with a system which only utilizes unlicensed spectrums (for instance, a Wi-Fi system), an access to a channel in the unlicensed spectrum will be significantly limited in the cellular system, in particular, with high loads.

[0003] Thus, there has been proposed an autonomous uplink (UL) transmission technology for the eLAA or MF system, for example. With this technology, a terminal device (such as a UE) can initiate UL transmission autonomously without scheduling of a network device (such as eNB). In the context of the present disclosure, autonomous uplink (or UL) transmission refers to a process of initiating the UL transmission by the terminal device when needed without the scheduling of the network. By this autonomous UL transmission, chances for the terminal device to access UL channels are increased remarkably. Furthermore, when the load in the network is low, the autonomous UL transmission performed by the terminal device may effectively reduce UL transmission delay.

[0004] For the autonomous UL transmission of the terminal device, one key aspect is how to allocate resource positions for the autonomous UL transmission, and the resource positions may influence the amount of obtained performance gain. For example, frame structures utilized for the unlicensed spectrums are typically very flexible. Any sub-frame can serve as a downlink (DL) sub-frame or a UL sub-frame. Thus, if the terminal device initiates the UL transmission autonomously, an ongoing DL or UL transmission from other terminal devices is very likely to be interfered. Furthermore, before the UL transmission is performed, a Listen-Before-Talk (LBT) process is typically performed, which would result in an additional DL-to-UL or UL-to-DL transition, thereby reducing the actual competitiveness of the terminal devices contending for the channel. Therefore, there is a need to design a more flexible resource allocation approach for the autonomous UL transmission in the unlicensed spectrums.

SUMMARY

[0005] In generally, embodiments of the present disclosure provide a method for autonomous uplink signal transmission and a corresponding terminal device and network device.

[0006] In a first aspect, embodiments of the present disclosure provide a method implemented at a terminal device in a communication network. The method comprises: receiving, from a network device in a communication network, an indication of a resource configuration for transmitting an autonomous uplink signal to the network device; determining, based on the received indication of the resource configuration, a sub-frame for transmitting the autonomous uplink signal; and transmitting the autonomous uplink signal to the network device in the determined sub-frame.

[0007] In a second aspect, embodiments of the present disclosure provide a method implemented at a network device in a communication network. The method comprises: determining a resource configuration associated with a sub-frame in which an autonomous uplink signal is to be received from the terminal device in the communication network; and indicating the resource configuration to the terminal device.

[0008] In a third aspect, embodiments of the present disclosure provide a terminal device. The terminal device comprises: a transceiver configured to receive, from a network device in a communication network, an indication of a resource configuration for transmitting an autonomous uplink signal to the network device; and a controller configured to determine a sub-frame for transmitting the autonomous uplink signal based on the received indication of resource configuration; wherein the transceiver is further configured to transmit the autonomous uplink signal to the network device in the determined sub-frame.

[0009] In a fourth aspect, embodiments of the present disclosure provide a network device. The network device comprises: a controller configured to determine a resource configuration associated with a sub-frame in which an autonomous uplink signal is to be received from the terminal device in the communication network; and a transceiver configured to indicate the resource configuration to the terminal device.

[0010] It is to be understood from the following description that according to embodiments of the present disclosure, the terminal device transmits an autonomous UL signal to the network device using the resources configured in the communication network so that interferences from the autonomous UL transmission to the scheduled DL/UL transmission may be efficiently reduced.

[0011] It is to be understood that contents as described in the SUMMARY portion are not intended to identify key or important features of embodiments of the present disclosure or used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Through the following detailed description with reference to the accompanying drawings, the above and other objectives, features, and advantages of the embodiments of the present disclosure will become more apparent. In the drawings, the same or similar reference signs refer to the same or similar elements, in which:

[0013] FIG. 1 illustrates an example scenario in which a network device and a terminal device contend for the channel at the same time;

[0014] FIG. 2 illustrates example influences of the conventional resource configuration approach for the autonomous UL transmission on the scheduled UL transmission;

[0015] FIG. 3 illustrates an example communication network in which embodiments of the present disclosure can be implemented;

[0016] FIG. 4 illustrates a flowchart of an example method implemented at a terminal device according to some embodiments of the present disclosure; [0017] FIG. 5 illustrates an example periodic sub-frame configuration according to some other embodiments of the present disclosure;

[0018] FIG. 6 illustrates an example of using a scheduled DL sub-frame as a reference sub-frame according to some other embodiments of the present disclosure;

[0019] FIG. 7 illustrates an example of using a scheduled UL sub-frame as a reference sub-frame according to some other embodiments of the present disclosure; [0020] FIG. 8 illustrates a flowchart of an example method implemented at a network device according to some embodiments of the present disclosure;

[0021] FIG. 9 illustrates a block diagram of an apparatus according to some embodiments of the present disclosure; [0022] FIG. 10 illustrates a block diagram of an apparatus according to some other embodiments of the present disclosure; and

[0023] FIG. 11 illustrates a block diagram of a device according to some embodiments of the present disclosure;

[0024] Through the drawings, the same or similar reference numbers represent the same or similar elements.

DETAILED DESCRIPTION

[0025] Embodiments of the present disclosure will be described in more details with reference to the drawings. Although the drawings show some embodiments of the present disclosure, it is to be understood that the present disclosure may be implemented in various manners and should not be construed as being limited to the embodiments explained herein. On the contrary, the embodiments are provided for a more thorough and complete understanding of the present disclosure. It is to be understood that the drawings and embodiments of the present disclosure are only for the purpose of illustration, without suggesting any limitations on the protection scope of the present disclosure. [0026] As used herein, the term "network device" refers to a base station or other entities or devices having the function of receiving and transmitting information in the communication network, through which the terminal device may access the network or receive services. The "base station" (BS) may represent a node B (NodeB or NB), an Evolved Node B (eNodeB or eNB), a remote radio unit (RRU), a radio-frequency head (RH), a remote radio head (RRH), a repeater, or a low power node such as a Picocell, a Femto cell and the like. In the context of the present disclosure, for the purpose of discussion, the terms "terminal device" and "base station" can be used interchangeably, and the eNB may be mainly used as an example of the network device.

[0027] As used herein, the term "terminal device" or "user equipment" (UE) refers to any terminal device that can perform wireless communication with base stations or with each other. As an example, the terminal device may include a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), a mobile station (MS), or an access terminal (AT) and the above devices mounted on a vehicle. In the context of the present disclosure, for the purpose of discussion, the terms "terminal device" and "user equipment" can be used interchangeably

[0028] As used herein, the term "autonomous uplink (UL) signal" refers to an UL signal transmitted by the terminal device to the network device in the manner of autonomous UL transmission. That is, the terminal device transmits the UL signal to the network device without scheduling of the network device.

[0029] As used herein, the terms "comprise", "include" and their variants are to be read as open terms that mean "include, but is not limited to". The term "based on" is to be read as "based at least in part on". The term "one embodiment" is to be read as "at least one embodiment"; the term "another embodiment" is to be read as "at least one other embodiment". Definitions of other terms will be presented in the following description.

[0030] As described above, for the autonomous UL transmission in the unlicensed spectrums, it is necessary to design a more flexible approach of resource configuration. A convention approach is to add a delay mechanism on the basis of random selection of the terminal device. For example, the terminal device may randomly select resources for autonomous UL transmission in the unlicensed spectrums, for example, including time and frequency resources. As described above, the approach of randomly selecting the resources may cause collisions between the autonomous UL transmission and the DL or UL transmission scheduled by network device. According to this approach, the terminal device adds, on the basis of the random selection of the resources for the autonomous UL transmission, a delay mechanism to avoid using scheduled DL or UL resources for the autonomous UL transmission.

[0031] For example, the terminal device may be aware of the presence of the scheduled DL transmission by detecting downlink reference signals or decoding downlink transmission configuration signaling in the common physical downlink control channel (Common-PDCCH) transmitted by the network device. By detecting or decoding C-PDCCH, the terminal device may also know timing offset and duration of a scheduled UL burst know the scheduled UL resources. Then, the terminal device may avoid the scheduled DL/UL transmission when performing the autonomous UL transmission.

[0032] However, the above conventional approach would cause the following problems. First, the collisions with the scheduled DL transmission are still possible. For example, if the terminal device and the network device obtain the channel at the same time, then it is impossible for the terminal device to detect and avoid the scheduled DL transmission. In this case, as temporal timing (such as frame/sub-frame timing) is usually aligned, that is, the time boundaries of the UL and DL transmission are the same, the autonomous UL transmission will collide with the scheduled DL transmission.

[0033] Second, the above conventional approach may cause DL transmission delay. FIG. 1 illustrates a case in which the network device (such as the eNB) and the terminal device (such as the UE) contend for channels at the same time. In this example, both the network device and the terminal device detect clear channels through clear channel assessment (CCA). The terminal device completes the LBT process earlier than the network device. Then, the terminal device performs autonomous UL transmission on the physical uplink shared channel (PUSCH) during a time period 106 in the frames #N+1 102 and #N+2 104. As shown, until the terminal device terminates the autonomous PUSCH transmission, the CCA process of the network device is failed. The network device can only perform transmission on the physical downlink shared channel (PDSCH) in the frame #N+3 108. It can be seen that the gain of the autonomous UL transmission at that time is at the expense of reduction of DL throughput and increase of the DL transmission delay.

[0034] Third, the above conventional approach may also influence the scheduled UL transmission. FIG. 2 illustrates an example for such influence. As shown, considering scheduling delay, a time gap 202 may be set between a DL sub-frame and an UL sub-frame scheduled by the network device. If the terminal device selects these resources (such as time intervals 204 and 206) for the autonomous UL transmission, then the scheduled DL-UL frame structure will be destroyed. For example, the scheduled UL sub-frames 208 and 210 would be caused to fall outside of the maximum channel occupancy time (MCOT) 212 required by the network device. This means that some terminal devices need to perform LBT Cat4 (category 4) for a longer duration before performing UL transmission, thereby reducing the chances for these terminal devices to access the channel. Therefore, autonomous UL transmission should avoid using blank resources introduced in consideration of the scheduling delay. [0035] In order to at least in part solve the above problems and other potential problems, embodiments of the present disclosure provides a resource allocation scheme for the autonomous UL transmission. Based on this scheme, the terminal device utilizes resources configured in the communication network to transmit an autonomous UL signal to the network device so as to reduce interferences from the autonomous UL transmission to the scheduled DL/UL transmission.

[0036] FIG. 3 illustrates an example communication network 300 in which embodiments of the present disclosure can be implemented. The communication network 300 includes two terminal devices 310-1 and 310-2 (collectively referred to as a "terminal device 310") and a network device 320. The network device 320 may communicate with the terminal device 310, and the terminal devices 310-1 and 310-2 may communicate with each other via the network device 320. It shall be appreciated that the number of network devices and terminal devices illustrated in FIG. 3 is only for the purpose of illustration, without suggesting any limitation. The network 300 may include any suitable number of network devices and terminal devices.

[0037] Communication in the network 300 may be compliant with any suitable wireless communication technology and the corresponding communication standard. The examples of communication technology may include, but not limited to, Long Term Evolution (LTE), LTE-Advanced (LTE- A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), Wireless Local Area Network (WLAN), Worldwide Interoperability for Microwave Access (WiMAX), Bluetooth and Zigbee technologies, and the like. Moreover, the communication may be performed according to any suitable communication protocol, including but not limited to Transmission Control Protocol (TCP)/Internet Protocol (IP), Hypertext Transfer Protocol (HTTP), User Datagram Protocol (UDP) and Session Description Protocol (SDP), and on the like.

[0038] According to the embodiments of the present disclosure, resources for transmitting the autonomous UL signal from the terminal device 310 to the network device 320 are configured at the network side. The resources may include sub-frames in the time domain and may include frequency resource blocks in the licensed or unlicensed spectrums in the frequency domain. As an example, the resources may be predefined by the network 300 or configured by the network device 320. The embodiments will be described in the following paragraphs. In this manner, the interferences from the autonomous UL transmission to the scheduled DL/UL transmission may be avoided effectively.

[0039] Principles and embodiments of the present disclosure will be described below from the perspective of the terminal device 310 and the network device 320, respectively, with reference to FIGS. 4-8. Reference is first made to FIG. 4 which shows a flowchart of an example method 400 implemented at a terminal device according to some embodiments of the present disclosure. The method 400 can be implemented at the terminal device 310 in the communication network 300 shown in FIG. 3. [0040] As shown, at block 405, the terminal device 310 receives, from the network device 320, an indication of a resource configuration for transmitting an autonomous UL signal to the network device. At block 410, based on the received indication of the resource configuration, the terminal device 310 determines a sub-frame for transmitting the autonomous UL signal. At block 415, the terminal device 310 transmits the autonomous UL signal to the network device 320 in the sub-frame.

[0041] As described above, the resources may be predefined by the network 300. For example, the network 300 may predefine, based on frame/sub-frame timing, several periodic sub-frames per frame or per several frames dedicated for the autonomous UL transmission. Accordingly, the terminal device 310 may determine the periodic sub-frame predefined for transmitting the autonomous UL signal in a frame when transmitting the UL signal autonomously to the network device 320.

[0042] As described above, the frame/sub-frame timing is generally aligned. In other words, the sub-frames for the autonomous UL transmission and the scheduled DL transmission have the same boundary. In this case, in order to further prevent interferences from the autonomous UL transmission to the scheduled DL transmission, in some embodiments, the autonomous UL transmission may be delayed for several time slots (referred to as "a first set of time slots") in the predefined periodic sub-frame. The time length of the time slots for delaying may be any suitable time length. As an example, a time slot with a time length of a symbol period may be delayed. [0043] Accordingly, the terminal device 310 may detect a DL signal from the network device 310 in the first set of time slots within a sub-frame. If no DL signal is detected, then the terminal device 310 transmits the autonomous UL signal to the network device 320 in a plurality of time slots (referred to as "a second set of time slots") subsequent to the first set of time slots within the sub-frame. If the DL signal is detected, the terminal device 310 may determine that the channel detecting result is busy, and will not perform the autonomous UL transmission at the predetermined time, thereby avoiding interfering with DL signals.

[0044] FIG. 5 illustrates a detailed example of a periodic sub-frame configuration. In this example, each frame (such as a frame #1 502, a frame #2 504 and a frame #3 506) has two sub-frames (for instance, a sub-frame #7 508 and a sub-frame #8 510) predefined for the autonomous UL transmission. The terminal device 310 further detects the DL transmission from the network device 320 during a first symbol period (not shown) of the sub-frame #7 508 in each frame. As shown in FIG. 5, the terminal device 310 does not detect the DL transmission in the sub-frame #7 508 of the frame #1 502, but does detect the DL transmission during the first symbol period in the sub-frame #7 508 of the frame #2 504. Accordingly, the terminal device 310 does not perform the UL transmission in the frame #2 504, but transmits the autonomous UL signal to the network device 320 in the next autonomous UL transmission opportunity (such as the sub-frames #7 508 #8 510 in frame #3 506).

[0045] In addition to the sub-frames predefined as the time resources, the network 300 may further predefine the frequency resources for the autonomous UL transmission. For example, frequency resource blocks may be predefined for the autonomous UL transmission. The frequency resource blocks may be in the licensed or unlicensed spectrums. In the example shown in Fig. 5, for the sub-frame #7 508, the frequency bands 512 and 514 are predefined for the autonomous UL transmission; and for the sub-frame #8 510, the frequency bands 516 and 518 are predefined for the autonomous UL transmission. Accordingly, the terminal device 510 may transmit the autonomous UL signal to the network device 520 on these frequency bands.

[0046] In addition to the sub-frame predefined by network for the autonomous UL transmission, as described above, the sub-frame may be configured by the network device 320. The network device 320 may implement this configuration based on any suitable factor. For example, the network device 320 may configure the position of the sub-frame based on a traffic level and/or interference conditions and on the like. Alternatively, the network device 320 may also configure the position of the sub-frame based on the scheduled DL-UL frame structure so that the autonomous UL transmission will not destroy the scheduled UL frame structure. The embodiments at network device 320 will be illustrated below in detail with reference to FIG. 8. [0047] Accordingly, the terminal device 310 may receive the indication of the resource configuration from the network device 320. The terminal device 310 may retrieve this indication from any suitable messages sent from the network device 320. For example, the terminal device 310 may retrieve this indication from broadcast signaling, radio resource control (RRC) layer or layer 3 (L3) signaling, or physical layer or layer 1 (LI) signaling from the network device 320. This indication may be explicit or implicit, which will be detailed in the following paragraphs.

[0048] According to the embodiments of the present disclosure, the indication of the resource configuration may be implemented in any suitable manner. In some embodiments, the indication of the position of a reference sub-frame associated with the sub-frame may be used as the indication of the resource configuration. Accordingly, the network device 310 may determine the position of the sub-frame based on the indication of the position of the reference sub-frame received from the network device 320. [0049] The reference sub-frame may be any suitable sub-frame associated with the sub-frame. In the embodiment in which the network device 320 configures the sub-frame based on the scheduled DL-UL frame structure, the last DL sub-frame scheduled by the network device 320 for DL transmission may be used as the reference sub-frame, and the sub-frame subsequent to the reference sub-frame may be configured for the autonomous UL transmission of the terminal device 310. Accordingly, after an indication of the position of the scheduled last DL sub-frame is received from the network device 320, the terminal device 310 may determine the sub-frame after this position as the sub-frame for the autonomous UL transmission. The sub-frame in any suitable position later than the last DL sub-frame as the sub-frame for the autonomous UL transmission. In this manner, the transmission of the autonomous UL signal may be prevented from occupying the scheduled DL sub-frames so as to avoid destroying the scheduled DL-UL frame structure.

[0050] A detailed example of using the last scheduled DL sub-frame as reference sub-frame will be discussed below with reference to FIG. 6. As shown, in the frame #1 602, upon the successful LBT, the network device 320 obtains eight sub-frames 604-618 for transmission. In the eight sub-frames, the network device 320 schedules the first five sub-frames 604-612 for the DL transmission and the last three sub-frames 614-618 for the UL transmission.

[0051] In this example, the last scheduled DL sub-frame (such as the DL sub-frame 612) is configured as the reference sub-frame, and the sub-frame subsequent to this sub-frame (such as the UL sub-frame 614) is configured as the sub-frame for the terminal device 310 to perform the autonomous UL transmission. Accordingly, the terminal device 310 may receive, from the network device 320, an indication of the position of the last scheduled DL sub-frame 612 and then determine the first UL sub-frame 614 after this position as the sub-frame. Thus, the terminal device 310 may use the UL sub-frame scheduled by the network device 320 to perform the transmission of the autonomous UL signal so that the DL-UL frame structure scheduled by the network device 320 may not be destroyed. [0052] Similar to the manner of the network predefinition, in addition to the configuration of the sub-frame as the time resources, the network device 320 may further configure the frequency resources for the autonomous UL transmission, for example, the predetermined frequency resource blocks for the autonomous UL transmission. In the example shown in FIG. 6, the frequency resource blocks 620 and 622 are configured for the sub-frame 614, and the frequency resource blocks 614 and 626 are configured for the sub-frame 616.

[0053] In addition to the configuration of the last scheduled DL sub-frame as the reference sub-frame, in some embodiments, the UL sub-frames scheduled by the network device 320 for the UL transmission may be configured as the reference sub-frame. For example, a certain UL sub-frame in the scheduled UL sub-frames can be used as the reference sub-frame, and this UL sub-frame or a sub-frame in any suitable position later than this UL sub-frame is used as the sub-frame for the autonomous UL transmission. Alternatively, the network device 320 may also use all the scheduled UL sub-frames as reference sub-frames, and indicate them to the terminal device 310. Accordingly, the terminal device 310 may select the sub-frame for the autonomous UL transmission from the scheduled UL sub-frames. [0054] FIG. 7 illustrates a detailed example of such a sub-frame configuration. In this example, the last UL sub-frame 702 (or the sub-frame 704 or 706) scheduled by the network device 320 is used as the reference sub-frame, and the sub-frame 708 subsequent to the sub-frame 702 is used as the sub-frame for the autonomous UL transmission. It is to be understood that a further scheduled UL sub-frame may also be used as the reference sub-frame. For example, the penultimate scheduled UL sub-frame 710 in each frame may be used as the reference sub-frame, and the subsequent last UL sub-frame 702 may be used as the sub-frame. In the example shown in FIG. 7, for the frequency resources, the network device 320 configures a whole frequency band 712 for the autonomous UL transmission.

[0055] As described above, the indication of the resource configuration received by the terminal device 310 from the network device 320 may be explicit or implicit. Accordingly, the indication of the position of reference sub-frame received by the terminal device 310 from the network device 320 as the indication of the sub-frame may also be explicit or implicit. For example, the explicit indication of the position of the reference sub-frame may be included in broadcast signaling, RRC layer (or L3) signaling, or physical layer (or LI) signaling sent by the network device 320. By receiving such signaling, the terminal device 310 may obtain an explicit indication of the position of the reference sub-frame. [0056] In the embodiment of using the scheduled DL or UL sub-frame as the reference sub-frame, the position of the reference sub-frame may be implicitly indicated by the C-PDCCH transmitted by the network device 320. For example, the C-DPCCH may include the position information of the scheduled DL end sub-frame, the timing offset of the scheduled UL burst, the duration of the scheduled UL burst, and on the like. By detecting or decoding the C-PDCCH, the terminal device 310 may obtain the position information of the last scheduled DL or UL sub-frame that can be used as the reference sub-frame.

[0057] By determining the position of the sub-frame based on the scheduled DL-UL frame structure, it is possible to enable the sub-frame to float dynamically in accordance with the ongoing DL and UL transmission bursts. This manner of the sub-frame configuration is more suitable to a high-load scenario in which the scheduled DL and UL bursts may occur frequently because the sub-frames configured in this manner can be better matched with the flexibly scheduled DL-UL frame structure and have less influence on the LBT process for the scheduling transmission.

[0058] In the case that the scheduled transmission occurs less frequently due to lower traffic load or channel congestion, the approach of predefining the periodic sub-frames by the network will be more advantageous. This is due to the fact that the scheduled DL or UL sub-frame that acts as the reference sub-frame appears very seldom, causing the number of corresponding sub-frames insufficient as well as considerable delay for the autonomous UL transmission; and the periodically configured sub-frames may effectively reduce the autonomous UL transmission delay under the low-load conditions.

[0059] In view of further improvement of the overall performance of the system, in some embodiments, the periodic and dynamic sub-frame configurations may be combined. As an example, a plurality of sub-frame configurations may be predefined in the network 300, which include periodically and dynamically configured sub-frames. These configurations are known to the devices in the network 300 (for example, including the terminal device 310 and the network device 320). The network device 320 may select the sub-frame configuration to be used based on the actual traffic and interference conditions, and may indicate the selected sub-frame configuration to the terminal device 310.

[0060] In addition to the sub-frames as the time resources, it is also possible to predefine the frequency resources, modulation and coding schemes (MCSs), periods and on the line in network 300. For example, the resource configuration including sub-frames, frequencies, MCSs and/or periods may be predefined. Table 1 provides a detailed example as below.

Table 1

[0061] In this example, eight types of resource configurations are predefined in the network 300, and each resource configuration includes dynamically configured sub-frames (represented as "type 1") or periodically configured sub-frames (represented as "type 2"). In addition, each resource configuration further includes the frequency resources and MSCs. These resource configurations are known to the terminal device 310 and network device 320.

[0062] The network device 320 may select one of the eight types of resource configurations and indicate it to the terminal device 310. Accordingly, after receiving an indication of the predefined resource configuration from the network device 320, the terminal device 310 may determine a sub-frame for the transmission of the autonomous UL signal based on the association between the predefined resource configuration and the sub-frame. In addition, the terminal device 310 may further determine the modulation and coding scheme based on the association between the predefined resource configuration and the modulation and coding scheme, and then use this modulation and coding scheme to transmit the autonomous UL signal to the network device 320. [0063] FIG. 8 is a flowchart of an example method 800 implemented at a network device according to some embodiments of the present disclosure. The method 800 can be implemented at the network device 320 in the network 300 shown in FIG. 1.

[0064] As shown, at block 805, the network device 320 determines the resource configuration associated with the sub-frame in which the autonomous UL signal is to be received from the terminal device 310. At block 810, the network device 320 indicates this resource configuration to the terminal device 310.

[0065] As described above, the network device 320 may perform the above resource configuration determination based on any suitable factors. In some embodiments, the network device 320 may configure the position of the sub-frame dynamically based on the traffic and interference conditions. In this manner, the interferences from the autonomous UL transmission to the scheduled DL/UL transmission can be reduced. Alternatively, the network device 320 may further configure the position of the sub-frame based on the scheduled DL-UL frame structure so that autonomous UL transmission will not destroy the scheduled UL frame structure; and the embodiments in this regard will be described in detail in the following paragraphs.

[0066] The indication of the resource configuration may be transmitted to the terminal device 310 in any suitable message. As described above, the examples of these messages include, but are not limited to, broadcast signaling, RRC layer (or L3) signaling, or physical layer (or LI) signaling. [0067] Furthermore, the indication of the resource configuration may be implemented in any suitable form. In some embodiments, the network device 320 may determine a reference sub-frame associated with the sub-frame, and then transmit the indication of the position of the reference sub-frame as the indication of the resource configuration to the terminal device 310. [0068] As described above, the reference sub-frame may be implemented as any suitable sub-frame associated with the sub-frame. In the embodiment of configuring the sub-frame based on the scheduled DL-UL frame structure, in order to prevent the autonomous UL transmission of the terminal device 310 from destroying the UL frame structure, the network device 320 may use the last scheduled DL sub-frame for the DL transmission as the reference sub-frame, and determine the sub-frame in any suitable position later than this DL sub-frame as a sub-frame for the transmission of the autonomous UL signal. Alternatively, the network device 320 may also configure the scheduled UL sub-frame for the UL transmission as the reference sub-frame, and use the UL sub-frame or a sub-frame in any suitable position later than the UL sub-frame as the sub-frame.

[0069] The network device 320 may implement the indication of the position of the reference sub-frame in any suitable manner. In some embodiments, the network device 320 may contain the explicit indication of the position of the reference sub-frame in the broadcast signaling, RRC layer (or L3) signaling or physical layer (or LI) signaling. In the embodiment of using the DL or UL sub-frame scheduled by the network device 320 as the reference sub-frame, the network device 320 may indicate the position of the reference sub-frame implicitly to the terminal device 310 with the position information of the scheduled DL end sub-frame, the timing offset of the scheduled UL burst, and the duration of the scheduled UL burst and the like.

[0070] As described above, the dynamic sub-frame configuration is more suitable to the high traffic load scenario in the network, while the periodic sub-frame configuration is more suitable to the low traffic load scenario. Accordingly, in order to improve the overall performance of the system, in some embodiments, when determining the resources for the transmission of the autonomous UL signal, the network device 320 may synthetically consider the two types of sub-frame configurations, namely, periodic and dynamic configurations. For example, as described above, the network 300 may predefine a plurality of resource configurations, including the periodically and dynamically configured sub-frames. These configurations are known to the terminal device 310 and the network device in the network 300. For instance, after selecting a certain resource configuration based on the actual traffic and interference conditions and on the like, the network device 320 may indicate the selected resource configuration to the terminal device 310.

[0071] In addition to the sub-frames used as the time resources, as shown in Table 1, it is also possible to predefine the associated frequency resources, modulation and coding schemes, periods and on the like, and accordingly to predefine a plurality of resource configurations including various predefined resource combinations. The network device 320 may select one or more of these resource configurations according to actual needs. For example, the network device 320 may select one or more resource configurations including the periodically configured sub-frames when the load is low and select one or more resource configurations including the dynamically configured sub-frames when the load is high.

[0072] In the case in which the network device 320 selects the periodically configured sub-frames, in order to further prevent interferences from the autonomous UL transmission to the scheduled DL transmission, in some embodiments, as described above, the autonomous UL transmission may be delayed for the first set of time slots (for example, a symbol period) in the predefined periodic sub-frame. Accordingly, the network device 320 may receive the autonomous UL signal from the terminal device 310 in a second set of time slots subsequent to the first set of time slots within this sub-frame.

[0073] Alternatively, the network device 310 may select the resource configuration including both the periodically and dynamically configured sub-frames. For example, the network device 310 may allocate the periodic sub-frames to terminal devices within MCOT and allocate the dynamic sub-frames to terminal devices outside MCOT to further improve the overall performance of the system.

[0074] After the resource configuration is determined, the network device 320 may indicate the selected resource configuration to the terminal device 310. For example, the network device 320 may transmit, to the terminal device 310, the corresponding resource configuration index shown in Table 1 as the indication of the resource configuration. [0075] It is to be understood that the operations and associated features performed by the terminal device 310 depicted with reference to FIGS. 4-7 are likewise applicable to the method 800 performed by the network device 320 and have the same effect. The details will not be repeated here.

[0076] FIG. 9 shows a block diagram of an apparatus 900 according to some embodiments of the present disclosure. It is to be understood that the apparatus 900 may be implemented at the side of the terminal device 310 shown in FIG. 3. As shown in FIG. 9, the apparatus 900 (such as terminal device 310) includes: a receiving unit 905 configured to receive, from a network device in the communication network, an indication of a resource configuration for transmitting an autonomous uplink signal to the network device; a first determining unit 910 configured to determine, based on the received indication of the resource configuration, the sub-frame for transmitting the autonomous uplink signal; and a transmitting unit 915 configured to transmit the autonomous uplink signal to the network device in the determined sub-frame.

[0077] It shall be appreciated that the apparatus 900 may further include units (not shown) for performing each step of the method 400 depicted with reference to FIGS. 4-7. The operations and features depicted with reference to FIGS. 4-7 are likewise applicable to the apparatus 900 and the units contained therein and have the same effect. The details will not be repeated here.

[0078] FIG. 10 shows a block diagram of an apparatus 1000 according to some embodiments of the present disclosure. It is to be understood that the apparatus 1000 may be implemented at a side of the network device 320 illustrated in FIG. 3. As shown, the apparatus 1000 (such as network device 320) includes: a second determining unit 1005 configured to determine the resource configuration associated with the sub-frame in which the autonomous uplink signal is to be received from the terminal device in the communication network; and an indicating unit 1010 configured to indicate the resource configuration to the terminal device. [0079] It is likewise to be understood that apparatus 1000 further includes units (not shown) for performing each step in the method 800 depicted with reference to FIG. 8. The operations and features depicted with reference to FIG. 8 are also applicable to the apparatus 1000 and the units contained therein and have the same effect. The details will not be repeated here. [0080] The units included in the apparatuses 900 and 1000 may be implemented in various manners, including software, hardware, firmware, or any combination thereof. In one embodiment, one or more modules may be implemented using software and/or firmware, for example, machine-executable instructions stored on the storage medium. In addition to or instead of machine-executable instructions, parts or all of the modules in the apparatuses 900 and 1000 may be implemented, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs), Application- specific Integrated Circuits (ASICs), Application- specific Standard Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), etc. [0081] The units shown in FIGS. 9 and 10 may be implemented, partially or entirely, as hardware modules, software modules, firmware modules or any combination thereof. In particular, in some embodiments, the flows, methods or processes described above may be implemented by hardware in a communication device. For example, the communication device may implement the methods 400 and 800 by means of its transmitter, receiver, transceiver and/or processor or controller.

[0082] FIG. 11 shows a block diagram of a device 1100 applicable to implement embodiments of the present disclosure. The device 1100 may be used to implement the terminal device, such as the terminal device 310 shown in FIG. 3; and/or implement the network device, such as the network device 320 shown in FIG. 3.

[0083] As shown, the device 1100 includes a controller 1110. The controller 1110 controls operations and functions of the device 1100. For example, in some embodiments, the controller 1110 may execute various operations by means of instructions 1130 stored in a memory 1120 coupled to the controller 1110. The memory 1120 may be of any appropriate type suitable for a local technical environment, and may be implemented using any suitable data storage technique, including without limitation to, a semiconductor based memory device, a magnetic memory device and system, an optical memory device and system. Although only one memory unit is shown in FIG. 11, there may be a plurality of physically different memory units in the device 1100.

[0084] The controller 1110 may be of any suitable type suitable for a local technical environment, and may include without limitation to, one or more of a general-purpose computer, a special purpose computer, a microcontroller, a digital signal processor (DSP), and a multi-core controller architecture based on controllers. The device 1100 may also include a plurality of controllers 1110. The controller 1110 is coupled to a transceiver 1140 and the transceiver 1140 may enable information receiving and transmitting by means of one or more antennas 1150 and/or other components.

[0085] When the device 1100 acts as the terminal device 310, the controller 1110 and the transceiver 1140 may operate in cooperation to implement the method 400 described with reference to FIGS. 4-7. When the device 1100 acts as the network device 320, the controller 1110 and the transceiver 1140 may operate in cooperation to implement the method 800 described with reference to FIG. 8. All features described with reference to FIGS. 4 to 8 are applicable to the device 1100 and will not be repeated here. [0086] Generally, various example embodiments of the present disclosure may be implemented in hardware, special purpose circuits, software, logic or any combinations thereof. Some aspects may be implemented in hardware while other aspects may be implemented in firmware or software executed by controllers, microprocessors or other computing devices. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method 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.

[0087] As an example, embodiments of the present disclosure may be described in the context of machine-executable instructions, which is included in program modules executed in devices on a target physical or virtual processor, for example. In general, program modules comprise routines, programs, libraries, objects, classes, components, data structures, and the like, that perform particular tasks or implement particular abstract data structures. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0088] Computer program codes for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The computer program codes may be provided to a processor of a general-purpose computer, a special purpose computer or other programmable data processing apparatuses, such that the program codes, when executed by the computer or other programmable data processing apparatuses, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program codes may be executed entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0089] In the context of the present disclosure, a machine-readable medium may be any tangible medium that contains or stores programs for or related to an instruction executing system, apparatus or device. The machine -readable medium may be a machine-readable signal medium or a machine-readable storage medium and may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, or any suitable combination thereof. More specific examples of the machine readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0090] Furthermore, although operations are depicted in a particular order, it is to 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. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

[0091] Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

I/We Claim:

1. A method implemented at a terminal device in a communication network, comprising:

receiving, from a network device in the communication network, an indication of a resource configuration for transmitting an autonomous uplink signal to the network device; determining, based on the received indication of the resource configuration, a sub-frame for transmitting the autonomous uplink signal; and

transmitting the autonomous uplink signal to the network device in the determined sub-frame.

2. The method according to Claim 1, wherein receiving the indication of the resource configuration comprises:

receiving, from the network device, an indication of a position of a reference sub-frame associated with the sub-frame, the reference sub-frame being associated with downlink sub-frames scheduled by the network device for downlink transmission or with uplink sub-frames scheduled by the network device for uplink transmission.

3. The method according to Claim 2, wherein determining the sub-frame comprises: if the reference sub-frame comprises the last downlink sub-frame scheduled by the network device for the downlink transmission, determining a sub-frame subsequent to the reference sub-frame as the sub-frame for transmitting the autonomous uplink signal.

4. The method according to Claim 2, wherein determining the sub-frame comprises: if the reference sub-frame comprises an uplink sub-frame scheduled by the network device for the uplink transmission, determining the reference sub-frame or a sub-frame subsequent to the reference sub-frame as the sub-frame for transmitting the autonomous uplink signal.

5. The method according to Claim 1, wherein receiving the indication of the resource configuration comprises:

receiving, from the network device, an indication of a predefined periodic sub-frame for transmitting the autonomous uplink signal to the network device.

6. The method according to Claim 5, wherein the predefined sub-frame comprises a first set of time slots and a second set of time slots, the second set of time slots being subsequent to the first set of time slots, and wherein transmitting the autonomous uplink signal comprises:

detecting a downlink signal from the network device in the first set of time slots in the predefined sub-frame of a frame; and

in response to failing to detect the downlink signal, transmitting the autonomous uplink signal to the network device in the second set of time slots.

7. The method according to Claim 1, wherein transmitting the autonomous uplink signal comprises:

determining, based on the received indication of the resource configuration, a frequency resource block for transmitting the autonomous uplink signal; and

transmitting the autonomous uplink signal to the network device on the frequency resource block in the sub-frame.

8. A method implemented at a network device in a communication network, comprising:

determining a resource configuration associated with a sub-frame in which an autonomous uplink signal is to be received from a terminal device in the communication network; and

indicating the resource configuration to the terminal device.

9. The method according to Claim 8, wherein determining the resource configuration comprises:

determining a reference sub-frame associated with the sub-frame, the reference sub-frame being associated with downlink sub-frames scheduled by the network device for downlink transmission or with uplink sub-frames scheduled by the network device for uplink transmission.

10. The method according to Claim 9, wherein determining the reference sub-frame comprises:

determining the last downlink sub-frame scheduled by the network device for the downlink transmission as the reference sub-frame, and a sub-frame subsequent to the reference sub-frame as the sub-frame for receiving the autonomous uplink signal.

11. The method according to Claim 9, wherein determining the reference sub-frame comprises:

determining an uplink sub-frame scheduled by the network device for the uplink transmission as the reference sub-frame, and the reference sub-frame or a sub-frame subsequent to the reference sub-frame as the sub-frame for receiving the autonomous uplink signal.

12. The method according to any of Claims 8-11, wherein indicating the resource configuration comprises:

transmitting an indication of a position of the reference sub-frame to the terminal device.

13. The method according to Claim 8, wherein determining the resource configuration comprises:

determining, within a predefined period, a predefined periodic sub-frame for receiving the autonomous uplink signal from the terminal device.

14. The method according to Claim 13, wherein the predefined sub-frame comprises a first set of time slots and a second set of time slots, the second set of time slots being subsequent to the first set of time slots, and the method further comprises:

receiving the autonomous uplink signal from the terminal device in the second set of time slots in the predefined sub-frame of a frame.

15. The method according to Claim 8, wherein determining the resource configuration comprises:

determining a frequency resource block for receiving the autonomous uplink signal.

16. The method according to Claim 8, wherein determining the resource configuration comprises:

selecting the resource configuration associated with the sub-frame from a plurality of predefined resource configurations.

17. A terminal device in a communication network, comprising:

a transceiver configured to receive, from a network device in the communication network, an indication of a resource configuration for transmitting an autonomous uplink signal to the network device; and

a controller configured to determine, based on the received indication of the resource configuration, a sub-frame for transmitting the autonomous uplink signal;

wherein the transceiver is further configured to transmit the autonomous uplink signal to the network device in the determined sub-frame.

18. The terminal device according to Claim 17, wherein the transceiver is configured to: receive, from the network device, an indication of the position of a reference sub-frame associated with the sub-frame, the reference sub-frame being associated with downlink sub-frames scheduled by the network device for downlink transmission for downlink transmission or uplink sub-frames scheduled by the network device for uplink transmission.

19. The terminal device according to Claim 18, wherein the controller is configured to: if the reference sub-frame comprises the last downlink sub-frame scheduled by the network device for the downlink transmission, determine a sub-frame subsequent to the reference sub-frame as the sub-frame for transmitting the autonomous uplink signal.

20. The terminal device according to Claim 18, wherein the controller is configured to: if the reference sub-frame comprises an uplink sub-frame scheduled by the network device for the uplink transmission, determine the reference sub-frame or a sub-frame subsequent to the reference sub-frame as the sub-frame for transmitting the autonomous uplink signal.

21. The terminal device according to Claim 17, wherein the transceiver is configured to: receive from the network device an indication of a predefined periodic sub-frame predefined for transmitting the autonomous uplink signal to the network device.

22. The terminal device according to Claim 21, wherein the predefined sub-frame comprises a first set of time slots and a second set of time slots, the second set of time slots being subsequent to the first set of time slots, and the transceiver is configured to:

detect a downlink signal from the network device in the first set of time slots in the predefined sub-frame of a frame; and in response to failing to detect the downlink signal, transmitting the autonomous uplink signal to the network device in the second set of time slots.

23. The terminal device according to Claim 17, wherein the controller is further configured to: determine, based on the received indication of the resource configuration, a frequency resource block for transmitting the autonomous uplink signal; and

wherein the transceiver is configured to: transmit the autonomous uplink signal to the network device on the frequency resource block in the sub-frame.

24. A network device in a communication network, comprising

a controller configured to determine a resource configuration associated with a sub-frame in which an autonomous uplink signal is to be received from a terminal device in the communication network; and

a transceiver configured to indicate the resource configuration to the terminal device.

25. The network device according to Claim 24, wherein the controller is configured to: determine a reference sub-frame associated with the sub-frame, the reference sub-frame being associated with downlink sub-frames scheduled by the network device for downlink transmission or uplink sub-frames scheduled by the network device for uplink transmission.

26. The network device according to Claim 25, wherein the controller is configured to: determine the last downlink sub-frame scheduled by the network device for the downlink transmission as the reference sub-frame and the sub-frame after the reference sub-frame as the sub-frame for receiving the autonomous uplink signal.

27. The network device according to Claim 25, wherein the controller is configured to: determine an uplink sub-frame scheduled by the network device for the uplink transmission as the reference sub-frame, and the reference sub-frame or a sub-frame subsequent to the reference sub-frame as the sub-frame for receiving the autonomous uplink signal.

28. The network device according to any of Claims 24-27, wherein the transceiver is configured to: transmit an indication of a position of the reference sub-frame to the terminal device.

29. The network device according to Claim 24, wherein the controller is configured to: determine a predefined periodic sub-frame of a frame for receiving the autonomous uplink signal from the terminal device.

30. The network device according to Claim 29, wherein the predefined sub-frame comprises a first set of time slots and a second set of time slots, the second set of time slots being subsequent to the first set of time slots, and the transceiver is configured to:

receive the autonomous uplink signal from the terminal device in the second set of time slots in the predefined sub-frame of the frame,.

31. The network device according to Claim 24, wherein the controller is configured to: determine a frequency resource block for receiving the autonomous uplink signal.

32. The network device according to Claim 24, wherein the controller is configured to: select the predefined resource configuration associated with the sub-frame from a plurality of predefined resource configurations.