Network element, wireless communication device, and method

Abstract

Embodiments of the present application disclose a network element, a wireless communication device, and a method. The network element includes a transmitter circuit for transmitting a message that can be received by a wireless communication device in a wireless communication system. The message includes information for assisting the wireless communication device to access unlicensed wireless resources. The network element is used to configure an uplink channel of the wireless communication device including a plurality of subframes. Each subframe has n orthogonal frequency division multiplexing (OFDM) symbols, where n is an integer. The network element can also be used to configure a maximum channel occupancy time (MCOT). Within the MCOT, the channel of the unlicensed wireless resource can be occupied. And the message includes information about the remaining time available to the wireless communication device in the MCOT.

Description

Technical Field

[0001] Embodiments of the present invention relate to a wireless communication system, and more particularly, to a network element, a wireless communication device, and a method that use a Listen Before Talk (LBT) procedure to support access to an unlicensed communication channel. The present invention can (but is not limited to) be applied to enhanced Licensed Assisted Access (eLAA) technology in a Long Term Evolution (LTE)-Advanced wireless communication system. Background Art

[0002] Wireless communication systems, such as the third-generation (3G) mobile phone standards and technologies, are well-known. Such 3G standards and technologies have been developed by the 3rd Generation Partnership Project (3GPP). Third-generation wireless communications have generally been developed to support macrocellular mobile phone communications. Such macrocells utilize high-power base stations (i.e., NodeB) to communicate with wireless communication units within a relatively large geographical coverage area. Typically, a wireless communication device (also referred to as User Equipment (UE)) communicates with the Core Network (CN) of a 3G wireless communication system via a Radio Network Subsystem (RNS). A wireless communication system typically includes a plurality of radio network subsystems, each radio network subsystem including one or more cells to which a UE can attach and thereby connect to the network. Each macrocellular RNS further includes a controller in the form of a Radio Network Controller (RNC), which is operably coupled to one or more NodeBs. Communication systems and networks have evolved towards broadband mobile systems. The 3rd Generation Partnership Project has developed Long Term Evolution (LTE) and Long Term Evolution-Advanced (LTE-A) solutions, namely the Evolved Universal Mobile Telecommunication System Terrestrial Radio Access Network (E-UTRAN) for the mobile access network, and the System Architecture Evolution (SAE) solution, namely the Evolved Packet Core (EPC) for the mobile core network. Macrocells in an LTE system are supported by base stations called eNodeB or eNB (Evolved Node B).

[0003] Current wireless communication networks operate using licensed radio spectrum, where access to the communication resources of the licensed radio spectrum is strictly controlled. Generally, multiple multiple access techniques (such as but not limited to: frequency division multiple access, time division multiple access, code division multiple access, space division multiple access, or a combination of one or more of these techniques) can be used to provide each user in the network with a "slice" of spectrum resources. Even when these techniques are used in combination, current and future network capacity remains very limited, especially in the case of using licensed radio spectrum, given the popularity of mobile telecommunications technology.

[0004] To increase or supplement capacity, network operators may also use unlicensed radio spectrum. For example, networks based on the LTE / LTE-Advanced standard have enhanced downlink, which can use the Licensed-Assisted-Access (LAA) procedure to operate on unlicensed spectrum. All communication devices need to complete the Listen-Before-Talk (LBT) procedure before accessing unlicensed channels.

[0005] Some LAA technologies use Clear Channel Assessment (CCA) checks on unlicensed spectrum to determine if there are other signals that have priority to use the channel. The base station (eNB) can start downlink transmission on an idle carrier, while the user equipment or terminal needs to send a signal to monitor the downlink carrier indicated by the base station. Typically, the UE can use energy detection to perform the CAA check to determine if there are other signals on a specific carrier, resource block, and / or channel, so as to determine whether the carrier, resource block, and / or channel is idle. The LBT procedure can be used for LAA carriers in unlicensed spectrum. Usually, carriers in licensed spectrum are specifically reserved for each UE, so there is no need to perform the LBT procedure and / or CCA check.

[0006] Currently, for LAA in LTE, the downlink (DL) and the uplink (UL) can be implemented in different ways. The base station eNB can start DL transmission on any channel at any time, while the UE can only start UL transmission on a specific subframe or specific channel allocated by the eNB using the UL permission message. Therefore, the opportunity for the UE to access unlicensed carriers is relatively small, resulting in limited UL performance.

[0007] There is a need to provide a method that can improve the efficiency of the UE accessing unlicensed wireless communication channels. Summary of the Invention

[0008] The present invention summary presents related concepts in a simplified form, which will be further described in the following detailed description. The present invention summary is not intended to identify the main features or essential features of the subject matter claimed in the present invention, nor is it intended to assist in determining the scope of the claimed subject matter.

[0009] According to one aspect of the present application, there is provided a network element for supporting communication functions in a wireless communication system. The network element includes a transmitter circuit for transmitting messages that can be received by wireless communication devices in the wireless communication system. The message includes information for assisting the wireless communication device to access unlicensed wireless resources. The network element is used to configure an uplink channel of the wireless communication device including a plurality of subframes. Each subframe has n orthogonal frequency division multiplexing (OFDM) symbols, where n is an integer. The network element may also be used to configure a maximum channel occupancy time (MCOT). Within the MCOT, the channel of the unlicensed wireless resource can be occupied. And the message includes information about the remaining time available to the wireless communication device in the MCOT.

[0010] According to another aspect of the present application, there is provided a wireless communication device for performing a listen-before-talk procedure. The wireless communication device has a receiver circuit. The receiver circuit is used to receive a message from a network element that supports communication functions in the wireless communication system. The message includes information for assisting the wireless communication device to use an uplink channel of the wireless communication device including a plurality of subframes to access unlicensed wireless resources. Each subframe has n orthogonal frequency division multiplexing (OFDM) symbols, where n is an integer. The message includes information about the remaining time available to the wireless communication device in the maximum channel occupancy time (MCOT).

[0011] According to yet another aspect of the present application, there is provided a method for enabling communication functions for a wireless communication device in a wireless communication system. The method includes: at a network element of the wireless communication system, transmitting a message to the wireless communication device, the message including information for assisting the wireless communication device to access unlicensed wireless resources; configuring an uplink channel of the wireless communication device including a plurality of subframes, each subframe having n orthogonal frequency division multiplexing (OFDM) symbols, where n is an integer; configuring a maximum channel occupancy time (MCOT), within which the channel of the unlicensed wireless resource can be occupied; and including in the message information about the remaining time available to the wireless communication device in the MCOT. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Further details, aspects, and embodiments of the present invention will be described hereinafter by way of example only with reference to the drawings. For the sake of simplicity and clarity of illustration, the elements in the drawings are not necessarily drawn to scale. For ease of understanding, similar reference numerals are used in each of the drawings.

[0013] Figure 1 is a simplified block diagram of a part of a cellular communication system and its operation according to an embodiment of the present application.

[0014] Figure 2 is a first timing diagram showing an authorized spectrum assisted access method using a listen-before-talk procedure.

[0015] Figure 3 and Figure 4 Exemplarily shows the second and third timing diagrams of the authorized spectrum access method for multiple UEs.

[0016] Figure 5 The table in shows the relevant parameters of the UE when accessing the unlicensed spectrum. Detailed implementation manners

[0017] Those skilled in the art will recognize and understand that the details of the described examples are only illustrative of some embodiments, and the teachings herein are applicable to various alternatives.

[0018] Please refer to Figure 1 , Figure 1 , which shows a part of the LTE cellular communication system operating according to an embodiment of the present application. The communication system is denoted by 100 and includes an evolved Node B (eNB) 101 that supports the LTE cell 102. In other embodiments, the eNB 101 may support multiple cells. The evolved Node B 101 includes a part of the radio access network, which may be the E-UTRAN in this example. User equipments 103a, 103b, and 103c are all located within the coverage area of the cell 102. Although Figure 1 only three user equipments are shown in, at any point in time in the actual situation, there may be more or fewer user equipments located in the cell 102 and in the connected mode. Figure 1The evolved packet core (EPC) in a wireless communication system may include a packet gateway P-GW 104 and a serving general packet radio service (GPRS) support node (SGSN) 105. The P-GW 104 can be used to connect a radio access network and a packet data network (e.g., a packet switched data network PSDN, the Internet). The SGSN 105 performs routing and tuning functions for traffic going to and from cell 102, while the P-GW 104 is connected to an external packet network. The EPC also includes a Mobility Management Entity (MME) 106. The eNB 101 is connected to the SGSN 105 via the mobility management entity 106. The eNB 101 is also connected to the P-GW 104 via the mobility management entity 106 and a serving gateway S-GW 107. The MME 106 can handle signaling control and mobility, while the S-GW 107 is a local anchor for user data. The eNB 101 is equipped with a receiver circuit (Rx) 108 and a transmitter circuit (Tx) 109 for transmitting messages to one or more user devices 103a, 103b, 103c. The transmitted messages include certain information (to be described in detail later) for assisting the user devices to access unlicensed radio resources, and this information is provided by the eNB in addition to licensed carriers. In Carrier Aggregation technology, unlicensed carriers can work together with licensed carriers. These messages can be included in Downlink Control Information (DCI). Each of the user devices 103a, 103b, and 103c may include a receiver 110 for receiving messages from the eNB 101 and a signal processor 111 for determining certain factors based on the information contained in the received messages, and the detailed description will be provided later.

[0019] As described above, the LBT procedures for the downlink and uplink can be implemented in various forms. 3GPP TS 36.213 describes one way of downlink LBT and defines four levels of priority. A contention window is defined for each level of priority, and a random value is selected and used to determine the number of CCAs to be performed in a single LBT procedure. By selecting a random value, the chance of collisions when different eNBs attempt to access the same unlicensed channel can be minimized. The size of the contention window can be determined according to the load of the channel. Although a small contention window can help an eNB quickly occupy the channel, it also limits the time available for the eNB to transmit data to a relatively short period. According to the currently proposed downlink LBT procedure, eNB 101 listens to the unlicensed channel to determine whether the channel is already in use by other devices. Once the channel is detected as idle, eNB 101 can start a delay period before the CCA countdown. If a signal is detected during the countdown period, the eNB will pause the countdown until the signal disappears, and then the countdown procedure can resume after the end of another delay period. When the countdown value reaches zero, the eNB can start transmission, but the transmission time cannot exceed the time allowed for the current priority (e.g., several milliseconds). Downlink LBT belongs to Category 4.

[0020] The LBT procedure defined by 3GPP can define the Maximum Channel Occupied Time (MCOT), which determines the maximum length of the downlink burst segment that the eNB can transmit on the unlicensed channel. However, in actual situations, the eNB 101 may not use the entire MCOT time. Therefore, according to the single-point transmission mode or the second type of LBT procedure, the remaining part can also be shared by one or more of the UEs 103a, 103b, and 103c. Different from the downlink, the uplink needs to multiplex multiple UEs. Therefore, the eNB 101 needs to coordinate these devices to access the same channel at the same time. To support multi-UE multiplexing, all UEs must start transmitting accurately at the same time. Otherwise, the signal sent by the UE that starts transmitting earliest will prevent the LBT procedures of other UEs from passing. In this example, the licensed spectrum-assisted access uplink transmission can be carried out in a subframe. Each subframe has n OFDM symbols, and at least one symbol is blank to create a gap. In these gaps, the UE can execute the LBT procedure and start transmitting immediately after the gap. In one embodiment, each subframe is 1 ms long and has 14 symbols, where the first and / or second symbols are blank. According to an embodiment of the present application, the eNB can indicate the positions of these gaps to the UEs 103a, 103b, and 103c. In these gaps, when the subsequent transmission burst segment of the UE is within the existing MCOT, the UE can execute the type 2 LBT; when the subsequent transmission burst segment of the UE cannot be completed within the existing MCOT, the UE can execute the type 4 LBT. If the type 4 LBT cannot be completed within one gap, the LBT procedure must continue in the next gap, and the next gap is at least 1 ms later.

[0021] To enable the UE to select a more appropriate LBT procedure (e.g., type 2 or type 4), it is best for the UE to know how much of the MCOT remains. For example, the UE will know how long it takes to transmit data. Therefore, if the UE can know the length of the remaining MCOT, it will be able to deduce whether the transmission can be completed within the remaining MCOT window. For example, if the UE determines that the transmission will not fall outside the MCOT window, then it can execute the type 2 LBT procedure. On the other hand, if the UE determines that the transmission will fall outside the MCOT window, then it can choose to execute the type 4 LBT procedure. In some cases, after the type 2 LBT fails, the type 4 LBT can be postponed, which will be described in detail later.

[0022] In one embodiment, the remaining MCOT can be informed to the UE by the eNB 101. This information can include, for example, 3 bits and is included in the message sent by the eNB in the downlink control information. Alternatively, the remaining MCOT can be derived by the signal processor 111 in the UE, which can be derived by counting down the subframes from a predefined MCOT value when the UE detects a downlink transmission. However, if the downlink transmission is not correctly detected, then this alternative has a defect. In this case, the remaining MCOT time will not be correctly calculated. This may cause the UE to occupy the unlicensed channel time when performing LBT incorrectly.

[0023] For LAA uplink, it is more preferable to use the Class 2 LBT procedure because it can help the UE acquire the unlicensed channel with a higher probability compared to other class procedures. In one embodiment of the present application, the eNB 101 can send an instruction to the UE, instructing the UE to switch from Class 4 to Class 2 LBT procedure in some cases. This instruction can be included in the message sent by the eNB in the downlink control information. The indication information of a single bit can be used within each subframe. If this bit information is not sent, then the UE continues to use Class 4 LBT. Alternatively, the UE can infer whether to switch from Class 4 to Class 2 LBT procedure according to other signal fields.

[0024] Please refer to Figure 2 the timing diagram in. It can be understood that the gap greater than 25 milliseconds between transmissions within the same MCOT period does not need to be included in the total transmission duration. Therefore, it can be said that the subframe in which the UE performs LBT but fails does not belong to a part of the MCOT.

[0025] In Figure 2 the example of, for frame 201 with a total length of 10 ms, which contains four downlink subframes (0 to 3) and six uplink subframes (4 to 9), they are allocated to a UE, and the downlink LBT creates an MCOT of 8 ms. Before starting the uplink transmission, a single UE needs to complete 25 μs of LBT (i.e., single-point transmission mode / Class 2 LBT). If this 25 μs of LBT fails to pass successfully, then the UE needs to wait until the start of the next subframe to perform another LBT procedure.

[0026] Figure 2 shows two examples. The first example shows how the Class 4 LBT is delayed when the LBT procedure fails. In the first example, the UE (e.g., Figure 1In 103a), it did not pass its first LBT at the start of subframe 4, but successfully passed the second LBT after one subframe. Therefore, the UE starts uplink transmission from subframe 5 and does not stop transmitting until the start of subframe 9, after which the MCOT initiated by the eNB ends. In the second example, the UE passed the first LBT, so it starts uplink transmission from subframe 4 and does not stop transmitting until the start of subframe 8, after which the MCOT initiated by the eNB ends. In both Example 1 and Example 2, the total transmission time is not greater than the MCOT time window initiated by the eNB. Therefore, the UE can continue with another transmission after a successful Class 4 LBT procedure (at the start of subframe 9 in the first example or at the start of subframe 8 in the second example). To comply with the standard, the Class 4 LBT procedure must be executed. Therefore, in the case shown in the first example, the Class 4 LBT procedure will be delayed.

[0027] The eNB can include a signal indicator in the message sent to the UE to indicate whether, for each uplink subframe, the Class 4 LBT can be postponed by one subframe when the LBT procedure fails within that subframe. Alternatively, by receiving a message indicating the remaining MCOT duration and obtaining the number and location of the allocated subframes, the signal processing capability of the UE can determine how many subframes the Class 4 LBT can be delayed after the LBT fails.

[0028] In one example, the eNB broadcasts to the UE one or more parameters to indicate how many uplink subframes have been allocated and their locations. Such an indicator can be referred to as the "size of the subframe" and can include 3 to 4 bits. The subframes allocated to a specific UE can be discontinuous. The UE must know the size of the subframe, otherwise it cannot correctly configure the uplink channel. For multiple UEs, an information field called the "multi-UE bitmap (one bit corresponding to each planned uplink subframe)" can be used to indicate to these UEs in which subframes blank gaps need to be set for the LBT procedure.

[0029] In another example, the eNB unicasts to the UE one or more parameters to indicate how many uplink subframes have been allocated and their locations. The subframes allocated to a specific UE can be discontinuous. For multiple UEs, an information field called the "multi-UE bitmap (one bit corresponding to each planned uplink subframe)" can be used to indicate to that UE in which subframes blank gaps need to be set for the LBT procedure.

[0030] Another information field called "MCOT Remaining Time" can be used to send information regarding the remaining MCOT duration, which can consist of 3 bits, and the UE can use this field after the eNB has completed downlink transmission. In one example, this remaining duration is in terms of subframes and indicates the remaining duration of the MCOT initiated by the eNB. If the uplink transmission can be completed within this remaining period, then Category 2 LBT is required. Otherwise, Category 4 LBT is required. This information field can be sent in broadcast form or unicast form. If it is sent to the UE in unicast form, then the eNB can adjust its value according to the subframes planned for this specific UE.

[0031] Please refer to Figure 3 and Figure 4 the timing diagrams in Figure 3 and Figure 4 which consider examples of multiple UEs. In Figure 1 and Figure 3 for a frame 301 with a total length of 10 ms, which contains four downlink subframes (0 to 3) and six uplink subframes (4 to 9), and they are allocated to two UEs, namely UE1 and UE2 (e.g., Figure 4 103a and 103b in Figure 3 ), and the downlink LBT creates an 8 - ms MCOT. Before starting the uplink transmission, each UE needs to complete 25 μs of LBT (i.e., unicast mode / Category 2 LBT). If this 25 - μs LBT fails, then the UE needs to wait until the start of the next subframe to perform another LBT procedure. If a subframe is not used by any UE, then it does not need to be considered when calculating the remaining MCOT duration. If a subframe is used by any UE, then it needs to be included in the remaining MCOT duration. In Figure 4 subframes 4 to 9 are allocated to UE1 for use, while subframes 6 to 8 are allocated to UE2 for use. In

[0032] Figure 3 and Figure 4 the information fields can be as described below. The first information field is "Uplink Subframe Size", and, inFigure 3 and Figure 4 In these examples of Figure 4 , the value of this field is 6, which means that a total of 6 subframes are allocated. The second information field is the "multi-UE bitmap" and is used to indicate the positions of the subframes used by one or more UEs. In Figure 3 's example, the value of this field is 001110, meaning that the third, fourth, and fifth subframes are allocated to multiple UEs, while the first, second, and sixth subframes are only allocated to one UE. In Figure 4 's example, the value of this field is 111000, meaning that the first, second, and third subframes are allocated to multiple UEs, while the fourth, fifth, and sixth subframes are only allocated to one UE. The third information field is the "MCOT remaining time" and the value is 4, which means that the remaining MCOT duration (after the downlink transmission is completed) includes four subframes. These information fields can be sent from the eNB to the UE via the uplink grant message, or can be broadcast simultaneously with the uplink grant transmission.

[0033] Referring again to Figure 3 , since the first two subframes are only allocated (or scheduled) to UE1, the signal processing function of UE1 can infer that if the LBT procedure fails, the Class 4 LBT can be delayed by at least two consecutive subframes. Referring again to Figure 4 , since the first subframe is scheduled for multiple UEs, the signal processing functions of UE1 and UE2 can infer that the Class 4 LBT cannot be postponed after the LBT fails.

[0034] Please refer to Figure 5 's table, Figure 5 's example describes the method by which a UE infers whether the Class 4 LBT procedure can be delayed based on an indicator from the eNB. In Figure 5 's example, the remaining MCOT time (after the eNB completes the downlink transmission) is equal to 3 (3 ms or 3 subframes), and this value is sent by the eNB to the UE in the uplink grant message. The uplink subframes are configured by the eNB and are represented by the numbers 4 to 9 in Figure 5 's row 501. The multi-UE bitmap with the value 010000 in row 502 means that only the subframe numbered 5 is used by multiple UEs, while the other subframes are only used by a single UE (but does not mean that it is always used by the same UE each time). In row 503, the shaded subframes 4, 5, 7, 8, and 9 are allocated to UE1. Row 504 shows the results of the LBT procedure, where "x" indicates that the Class 2 LBT fails, while "V" indicates passing. Row 505 shows whether a specific subframe is marked for transmission based on whether the remaining MCOT is involved. Row 506 is the remaining MCOT time inferred by UE1 after each subframe. Row 507 shows the category of the LBT procedure executed at a specific subframe.

[0035] At subframe 4, UE1 performs Category 2 (25 millisecond) LBT. This LBT fails. However, subframe 4 is only scheduled for a single UE (bitmap value is 0), and UE1 knows that it is the only UE scheduled to use this subframe. When this LBT fails, UE1 knows that this subframe is not being used by any other UE and can thus be excluded from the remaining MCOT time. Therefore, at the end of subframe 4, the remaining MCOT time remains at a value of 3 unchanged.

[0036] Subframe 5 is scheduled for multiple UEs (bitmap value is 1), and UE1 knows that it is only one of several UEs scheduled to use this subframe. When this LBT fails, UE1 cannot tell if the subframe is being used by other UEs. Therefore, this subframe must be counted in the transmission time. As a result, after subframe 5, the remaining MCOT time is reduced by 1 and is then equal to 2.

[0037] Subframe 6 is scheduled for use by a single UE, and UE1 is not scheduled to use this subframe (i.e., the subframe is blank). UE1 cannot tell if the subframe is being used by other UEs. This subframe must be counted in the transmission time. Therefore, after subframe 6, the remaining MCOT time is reduced by 1 and is then equal to 1.

[0038] Subframe 7 is similar to subframe 4 in that it is only scheduled for use by UE1, and in this example, the LBT performed by UE1 on subframe 7 fails, so this subframe is not included in the transmission time. As a result, after subframe 7, the remaining MCOT time does not decrease and remains equal to 1.

[0039] Subframe 8 is only scheduled for use by UE1, and UE1 passes the LBT procedure (denoted by the letter V in the table) and occupies this subframe. After subframe 8, the remaining MCOT time is reduced by 1 and its value drops to 0, which means that Category 4 LBT needs to be performed starting from subframe 9.

[0040] As can be seen from the above, the UE can determine when to perform the Category 4 LBT procedure. This determination process can be executed by a single processor in the UE.

[0041] In another embodiment, the UE is not configured to Figure 5Rather than deriving the remaining MCOT time on a per-subframe basis as shown, it is determined based on the signal from the eNB. For example, the "remaining MCOT time parameter" may be included in a downlink control information (DCI) message shared by multiple UEs. In this embodiment, the UE may monitor downlink signal transmissions. If no downlink signal transmission is received, then the UE may default to Class 4 LBT procedure. If a downlink signal transmission is received and the "remaining MCOT time parameter" indicates that the remaining time is 0, then the UE must perform Class 4 LBT. If a downlink signal transmission is received and the "remaining MCOT time parameter" indicates that the remaining time is 1, then the UE performs Class 2 LBT in the first subframe and Class 4 LBT in the next subframe. If a downlink signal transmission is received and the "remaining MCOT time parameter" is 2 or more, then Class 2 LBT may be performed in the first two and / or subsequent subframes.

[0042] In another embodiment, the UE is not configured to determine whether Class 4 LBT can be deferred, but rather is determined based on the signal from the eNB. Another field with a value of 0 or 1 may be used, where a value of 0 indicates that deferral is allowed when the LBT within this subframe fails, and a value of 1 indicates that deferral is not allowed. Taking Figure 5 as an example, the following table shows the corresponding situations.

[0043] Subframes Scheduled for the UE 4 5 6 7 8 9 Whether Delay is Allowed 0 1 1 0 0 0

[0044] Subframe 5 is not allowed because another UE is multiplexed and can use this subframe. Subframe 6 is also not allowed because this subframe is scheduled for another UE. All other subframes are allowed, so once the 25 μs LBT fails, the Class 4 LBT procedure can be deferred. The number of subframes for which deferral is allowed is the same as the number of subframes in which the LBT fails and has a "0" (i.e., deferral is allowed). Alternatively, subframe 6 may be removed from the above signal because it is not allocated to UE1 and UE1 also knows this. This option uses more downlink signals and uses the eNB to control all of the above operations.

[0045] The signal processing functions of the embodiments of this application may be implemented using computing systems or architectures known to those skilled in the art. Computing systems, such as desktop computers, portable computers or laptops, handheld computing devices (PDAs, cellular phones, palmtop computers, etc.), mainframes, servers, clients, or any other type of special or general computing device, may be used because they are applicable or suitable for a particular application or environment. The computing system may include one or more processors, which may be implemented using a general or special processing engine such as a microprocessor, microcontroller, or other control processing module.

[0046] The computing system may also include a main memory for storing information and instructions to be executed by the processor, such as random access memory (RAM) or other dynamic memory. Such main memory may also be used to store temporary variables or other intermediate information during the execution of instructions to be executed by the processor. The computing system may also include a read only memory (ROM) or other static storage device for storing static information and instructions for the processor.

[0047] The computing system may also include an information storage system, for example, which may include a media drive and a removable storage interface. The media drive may include a drive or other mechanism to support a fixed or removable storage medium, such as a hard disk drive, a floppy disk drive, a tape drive, an optical disk drive, a compact disc (CD), a digital video drive (DVD), a read or write drive (R or RW), or other removable or fixed media drives. For example, the storage medium may include, for example, a hard disk, a floppy disk, a tape, an optical disk, a CD, or a DVD, or other fixed or removable media read and written by the media drive. The storage medium may include a computer-readable storage medium having specific computer software or data stored therein.

[0048] In an alternative embodiment, the information storage system may include other similar components for allowing a computer program or other instructions or data to be loaded into the computing system. For example, these components may include a removable storage unit and an interface, such as a program cartridge and a cartridge interface, a removable memory (e.g., flash memory or other removable memory modules) and a memory slot, and other removable storage units and interfaces that allow software and data to be transferred from the removable storage unit to the computing system.

[0049] The computing system may also include a communication interface. Such a computing system can be used to allow software and data to be transferred between the computing system and external devices. In this embodiment, the communication interface may include a modem, a network interface (e.g., Ethernet or NIC card), a communication port (e.g., a Universal Serial Bus (USB) port), a PCMCIA slot and card, etc. The software and data transmitted through the communication interface are transmitted in the form of signals, which may be electrical, electromagnetic, optical, or other signals that can be received by the communication interface medium.

[0050] In this document, terms such as "computer program product", "computer-readable medium", etc. can generally be used to refer to tangible media, such as memories, storage devices, or storage units. These and other forms of computer-readable media can store one or more instructions for use by a processor of a computer system to cause the processor to perform specified operations. These instructions, commonly referred to as 'computer program code' (which may be grouped in the form of a computer program or other groupings), when executed cause the computing system to perform the functions of embodiments of the present invention. It is noted that this code can directly cause the processor to perform the specified operations, be compiled to do so, and / or be combined with other software, hardware, and / or firmware elements (e.g., libraries for performing standard functions) to do so.

[0051] In embodiments where software is used to implement elements, the software can be stored in a computer-readable medium and, for example, loaded into the computing system using a removable storage drive. When executed by a processor in the computer system, the control module (in this example, software instructions or executable computer program code) causes the processor to perform the functions of the present invention as described herein.

[0052] Furthermore, the inventive concept can be applied to any circuitry for performing signal processing functions within a network element. It is further envisioned that, for example, semiconductor manufacturers can use the inventive concept in the design of stand-alone devices, such as microcontrollers of digital signal processors (DSPs) or application-specific integrated circuits (ASICs) and / or any other subsystem elements.

[0053] It will be appreciated that, for purposes of clarity, the embodiments of the present invention have been described above with reference to a single processing logic. However, the inventive concept can equally well be implemented by multiple different functional units and processors to provide the signal processing functions. Thus, the reference to a particular functional unit is only to be regarded as a reference to a suitable means for providing the described function, rather than indicating a strict logical or physical structure or organization.

[0054] Aspects of the present invention can be implemented in any suitable form including hardware, software, firmware, and any combination thereof. Optionally, the present invention can be implemented at least in part as computer software running on one or more data processors and / or digital signal processors or configurable modular components (such as FPGA devices). Thus, the elements and components of embodiments of the present invention can be physically, functionally, and logically implemented in any suitable manner. In fact, the functions can be implemented in a single unit, multiple units, or as part of other functional units.

[0055] Although the present invention has been described in connection with some embodiments, it is not intended to limit the present invention to the specific forms set forth herein. On the contrary, the scope of the present invention is defined only by the appended claims. Additionally, although a feature is described in connection with a specific embodiment, those skilled in the art will recognize that multiple features described in the embodiments can be combined. In the claims, the term "comprising" does not exclude the presence of other elements or steps.

[0056] Furthermore, although listed separately, multiple devices, elements, or method steps can be implemented by, for example, a single unit or processor. Additionally, although the individual features can be included in different claims, these features can be advantageously combined, and inclusion in different claims does not mean that the combination of features is not feasible and / or advantageous.

[0057] Moreover, the inclusion of a feature in a class of claims does not mean a limitation to that class, but rather that the functionality is equally applicable to other claim classes.

[0058] In addition, the order of features in the claims does not mean that the features must be performed in any particular order, especially the order of the individual steps in method claims does not mean that the steps must be performed in that order. On the contrary, these steps can be performed in any suitable order. Additionally, a single reference to an element does not exclude multiple such elements. Thus, references to "a", "an", "first", "second", etc. do not exclude multiple.

[0059] Although the present invention has been described in connection with some embodiments, it is not intended to limit the present invention to the specific forms set forth herein.

[0060] On the contrary, the scope of the present invention is defined only by the appended claims. Additionally, although a feature is described in connection with a specific embodiment, those skilled in the art will recognize that multiple features described in the embodiments can be combined. In the claims, the term "comprising" does not exclude the presence of other elements or steps.

Claims

1. A network element for supporting communication functions in a wireless communication system, characterized in that: it includes a transmitter circuit for transmitting a message that can be received by a wireless communication device in the wireless communication system, the message including information for assisting the wireless communication device to access unlicensed wireless resources; the network element is used to configure an uplink channel of the wireless communication device including a plurality of subframes, each subframe having "n" orthogonal frequency division multiplexing (OFDM) symbols, where "n" is an integer; and the network element can also be used to configure a maximum channel occupancy time (MCOT), within which the channel of the unlicensed wireless resource can be occupied, and the message includes information about the remaining time available to the wireless communication device in the MCOT.

2. The network element according to claim 1, wherein, the remaining time is in units of subframes.

3. The network element according to claim 1, wherein, at least one symbol is blank to create a gap, and the wireless communication device can perform a listen-before-talk (LBT) procedure within the gap, and the message further includes at least one of the following information: the position of the gap, an instruction for switching the wireless communication device from Class 4 to Class 2 LBT procedure, an instruction for delaying the Class 4 LBT procedure by the wireless communication device after a previous LBT procedure fails.

4. The network element according to claim 1, wherein, the message is included in downlink control information (DCI).

5. The network element according to claim 2, wherein, the instruction for switching the wireless communication device from Class 4 to Class 2 LBT procedure includes an indicator of one bit per subframe.

6. The network element according to claim 2, wherein, the instruction for delaying the Class 4 LBT procedure by the wireless communication device after a previous LBT procedure fails is indicated by one bit per subframe.

7. The network element according to any one of the foregoing claims, wherein, the message further includes at least one of the following information: uplink subframe size and uplink subframe position.

8. The network element according to claim 1, wherein, the message includes information indicating on which subframe a blank gap needs to be set for the LBT procedure for multiple wireless communication devices multiplexed to the uplink channel.

9. A wireless communication device for performing a listen-before-talk procedure, characterized in that: it has a receiver circuit for receiving a message from a network element supporting communication functions in the wireless communication system; the message includes information for assisting the wireless communication device to use an uplink channel of the wireless communication device including a plurality of subframes to access unlicensed wireless resources, each subframe having "n" orthogonal frequency division multiplexing (OFDM) symbols, where "n" is an integer; and the message includes information about the remaining time available to the wireless communication device in the maximum channel occupancy time (MCOT).

10. The wireless communication device according to claim 9, wherein, At least one symbol is blank to create a gap within which the wireless communication device can perform a listen-before-talk (LBT) procedure; and The message further includes at least one of the following information: The location of the gap, An instruction for switching the wireless communication device from a Class 4 to a Class 2 LBT procedure, An instruction for delaying the Class 4 LBT procedure by the wireless communication device after a previous LBT procedure fails.

11. The wireless communication device according to claim 10, wherein, The message further includes information indicating on which subframe a blank gap needs to be set for an LBT procedure for multiple wireless communication devices multiplexed to an uplink channel.

12. The wireless communication device according to claim 11, wherein, The wireless communication device includes a signal processor for determining whether the Class 4 LBT procedure can be delayed after receiving a message from the network element and a previous LBT procedure fails, wherein the message includes information regarding the location of the gap and the remaining time of the MCOT.

13. The wireless communication device according to claim 12, wherein, The signal processor is used to determine whether the Class 4 LBT procedure can be delayed subframe by subframe after a previous LBT procedure fails.

14. The wireless communication device according to claim 13, wherein, If the LBT in a previous subframe allocated to a single UE fails, the signal processor is used to postpone the Class 4 LBT procedure by one subframe.

15. The wireless communication device according to claim 11, including a signal processor for determining whether the wireless communication device can switch from a Class 4 LBT procedure to a Class 2 LBT procedure according to information received from the network element regarding the remaining time of the MCOT.

16. The wireless communication device according to claim 15, wherein, The signal processor determines whether the wireless communication device can switch from a Class 4 LBT procedure to a Class 2 LBT procedure according to information received from the network element regarding the location of the gap.

17. A method for enabling a communication function for a wireless communication device in a wireless communication system, characterized in that, comprising: At a network element of the wireless communication system, transmitting a message to the wireless communication device, the message including information for assisting the wireless communication device to access unlicensed radio resources; Configuring an uplink channel of the wireless communication device including a plurality of subframes, each subframe having "n" orthogonal frequency division multiplexing (OFDM) symbols, where "n" is an integer; Configuring a maximum channel occupancy time (MCOT) within which the channel of the unlicensed radio resources can be occupied; and Including in the message the remaining time available to the wireless communication device within the MCOT.

18. The method according to claim 17, wherein, At least one symbol is blank to create a gap within which the wireless communication device can perform a listen-before-talk (LBT) procedure, and The message further includes at least one of the following information: The position of the gap Instructions for switching the wireless communication device from Class 4 to Class 2 LBT procedure Instructions for causing the wireless communication device to delay the Class 4 LBT procedure after a previous LBT procedure fails 19. The method according to claim 18, further comprising: Including the message in downlink control information (DCI).

20. The method according to claim 19, further comprising: At the wireless communication device, determining whether the Class 4 LBT procedure can be delayed after a previous LBT procedure fails

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