CN107295677B

CN107295677B - Feedback method and device for performing idle channel assessment

Info

Publication number: CN107295677B
Application number: CN201610202559.1A
Authority: CN
Inventors: 苟伟; 赵亚军; 彭佛才; 李新彩
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2016-03-31
Filing date: 2016-03-31
Publication date: 2023-10-17
Anticipated expiration: 2036-03-31
Also published as: WO2017167004A1; CN107295677A

Abstract

The invention provides a feedback method and a device for performing idle channel assessment, wherein the method comprises the following steps: when User Equipment (UE) is scheduled to send uplink data in an nth subframe of an unlicensed carrier, executing Clear Channel Assessment (CCA) detection before sending the uplink data, wherein n is a natural number; and feeding back a detection result of the CCA detection to the base station. The invention solves the problem of the reduced retransmission performance of the terminal caused by CCA failure in the LAA system in the related technology.

Description

Feedback method and device for performing idle channel assessment

Technical Field

The present invention relates to the field of communications, and in particular, to a feedback method and apparatus for performing clear channel assessment.

Background

In the related art, long Term Evolution (LTE) communication networks are all deployed and operated in licensed carriers, and as LTE advances, some companies propose "research on LTE deployment in unlicensed carriers" such as the us high-pass company thinks: with the rapid growth of data traffic, the licensed carrier will not be able to withstand the huge amount of data brought about by the rapid traffic growth in the near future. Consider that by deploying LTE in an unlicensed carrier, so as to share data traffic in the licensed carrier, the data volume pressure caused by traffic growth can be addressed. Meanwhile, the unlicensed carrier has the following characteristics: on one hand, because the unlicensed carrier does not need to be purchased or the carrier resource is zero-cost, the unlicensed carrier is free or low-cost; on the other hand, as the personnel and enterprises can participate in deployment, equipment of equipment providers can also participate in deployment, so that the admission requirement of unauthorized carriers is low; furthermore, the unlicensed carrier has sharing property, and when a plurality of different systems are operated therein or when different operators of the same system are operated therein, some sharing resource modes can be considered, so as to improve carrier efficiency.

In summary, although LTE deployment has significant advantages in unlicensed carriers, there are still problems in the deployment process; among them, many wireless access technologies (different communication standards are crossed, cooperation is difficult, network topology is various) and many wireless access sites (the number of users is large, cooperation difficulty is large, and centralized management overhead is large). Due to the large number of radio access technologies, various wireless systems exist in the unlicensed carrier, so that the wireless systems are difficult to coordinate with each other, and the interference is serious. Therefore, for LTE deployment in unlicensed carriers, there is still a need to support policing of unlicensed carriers, and most countries require support for listen-before-talk mechanisms when systems are deployed in unlicensed carriers. Interference caused by simultaneous use of unlicensed carriers between adjacent systems can be avoided by a listen-before-talk mechanism. And further, a contention back-off mechanism is introduced, namely, adjacent system stations (generally adjacent transmission nodes of the same system), so that interference caused when the adjacent transmission nodes of the same system use unlicensed carriers at the same time can be avoided after the contention back-off mechanism. In addition, in regulation, it is specified that devices (including a base station and a user equipment UE) using an unlicensed carrier need to perform a listen before talk mechanism before transmitting, and the listen before talk mechanism is called clear channel assessment (Clear Channel Assessment, abbreviated as CCA), also called (Listen Before Talk, abbreviated as LBT), and when a channel is clear, the devices can use the unlicensed carrier channel to perform data transmission. HARQ is used in combination with FEC and ARQ, known as hybrid automatic repeat request, hybird ARQ. The basic principle of HARQ is as follows:

The FEC technique is used at the receiving end to correct the portion of all errors that can be corrected.

And judging that the data packet with the error cannot be corrected through error detection.

And discarding the data packets which cannot be corrected, and requesting the same data packets to be retransmitted to the transmitting end.

In the LTE system, HARQ is supported, and the HARQ is used as one of the most main characteristics of the LTE system, so that the reliability of data transmission is improved. HARQ faces new problems in unlicensed carriers or licensed spectrum assisted access (License Assisted Access, abbreviated LAA) systems (LAA systems, i.e., systems where LTE is deployed on unlicensed carriers or systems where unlicensed carriers use LTE technology).

In the LAA system, during uplink transmission, since the UE needs to perform CCA to detect whether the channel is idle or not before the UE actually transmits after being scheduled for transmission, when the channel is idle, the UE can complete corresponding data transmission according to previous scheduling. However, if the UE fails to perform CCA, it is not clear by the base station whether the UE has transmitted the corresponding uplink data according to the previous schedule, and when this occurs during retransmission, the following effects may occur. First, the number of actual retransmissions by the UE is lower than the number of expected retransmissions specified by the standard, eventually resulting in reduced performance of HARQ retransmissions. Second, when the HARQ combining is caused, invalid data may be combined, which affects the performance of the HARQ combining.

In view of the above problems in the related art, no effective solution has been found yet.

Disclosure of Invention

The invention provides a feedback method and a device for performing clear channel assessment, which at least solve the problem that the retransmission performance of a terminal is reduced due to CCA failure in an LAA system in the related technology.

According to an aspect of the present invention, there is provided a feedback method of performing clear channel assessment, comprising: when User Equipment (UE) is scheduled to send uplink data in an nth subframe of an unlicensed carrier, executing Clear Channel Assessment (CCA) detection before sending the uplink data, wherein n is a natural number; and feeding back a detection result of the CCA detection to the base station.

Further, the detection result includes one of: success or failure, and feeding back the detection result of the CCA detection to the base station includes at least one of the following ways: when the CCA detection fails, the detection result is sent to a base station through a Physical Uplink Control Channel (PUCCH), or the detection result is sent to the base station through a resource for sending Uplink Control Information (UCI) in a Physical Uplink Shared Channel (PUSCH); when the CCA detection is successful, the detection result is sent to a base station through a PUCCH, or the detection result is sent to the base station through a resource for sending UCI in a PUSCH; and when the CCA detection is successful or failed, sending the detection result to a base station through a PUCCH, or sending the detection result to the base station through a resource for sending UCI in a PUSCH.

Further, when the CCA detection fails, transmitting the detection result to the base station through a PUCCH resource, including: transmitting the detection result to a base station through a physical uplink control channel PUCCH format 1; and/or when the CCA detection is successful, transmitting the detection result to the base station through a PUCCH resource, including: transmitting the detection result to a base station through a physical uplink control channel PUCCH format 1; wherein the PUCCH format 1 includes at least one of: the same coding scheme, time domain resource allocation scheme, frequency domain resource allocation scheme, code domain resource allocation scheme, and mapping transmission scheme as those of PUCCH format 1.

Further, when the CCA detection is successful or failed, transmitting the detection result to the base station through a PUCCH resource, including: transmitting the detection result to a base station through a PUCCH format 1 a; wherein the PUCCH format 1a includes at least one of: the same coding scheme, time domain resource allocation scheme, frequency domain resource allocation scheme, code domain resource allocation scheme, and mapping transmission scheme as those of PUCCH format 1 a.

Further, allocating different resource indexes of PUCCH format 1 or PUCCH format 1a for the detection result and acknowledgement/non-acknowledgement (ACK/NACK) or Scheduling Request (SR) by means of base station and UE Or calculating the resource index of the UE feedback detection result in the nth subframe by the CCE with the minimum index number in the control channel element CCE of the physical downlink control channel PDCCH of the uplink authorization information carried in the nth subframe or the enhanced PDCCH in a mode agreed by the base station and the UE>Is a value of (2); wherein said->And (3) the resource index of the PUCCH format 1 or 1a, wherein k is the number of interval subframes between the uplink authorization information transmission subframe and the corresponding uplink data transmission subframe.

Further, the saidAnd calculating time domain, frequency domain and code domain resources of the UE for sending the detection result according to a protocol LTE TS 36.211vd 00.

Further, feeding back the detection result of the CCA detection to the base station includes: and feeding back a detection result of the CCA detection to the base station in a subframe corresponding to the nth subframe or a first subframe after the corresponding subframe in the authorized carrier.

Further, when the subframe corresponding to the nth subframe in the authorized carrier is a downlink subframe, the detection result of the CCA detection is fed back to the base station in the 1 st uplink subframe after the subframe corresponding to the nth subframe in the authorized carrier by a mode agreed by the base station and the UE, and/or when the 1 st subframe after the subframe corresponding to the nth subframe in the authorized carrier is a downlink subframe, the detection result of the CCA detection is fed back to the base station in the 1 st uplink subframe after the 1 st subframe after the subframe corresponding to the nth subframe in the authorized carrier by a mode agreed by the base station and the UE.

Further, when the base station and the UE agree on the 1 st uplink subframe after the n subframes or the 2 nd uplink subframe after the n subframes to feed back the detection result of the CCA detection to the base station, the detection result further includes the accumulated CCA failure or success number of the UE.

Further, when the base station transmits the PDCCH or the enhanced PDCCH of the uplink grant information in the nth-kth subframe, the detection result is fed back to the base station in the nth or the (n+1) th subframe of the main carrier by the UE in a mode agreed by the base station and the UE, wherein k is the number of interval subframes between the uplink grant information transmission subframe and the corresponding uplink data transmission subframe.

Further, when the detection result is failure, the UE cannot send the nth subframe of the uplink data according to the uplink grant information, the UE considers the retransmission as invalid, and the number of the retransmission is excluded from the actual retransmission number counting result.

Further, when the base station receives the CCA detection result corresponding to the nth subframe and fails, or the base station knows that the UE fails due to CCA detection according to the CCA detection result fed back by the UE, the base station excludes the number of times of the current retransmission from the actual retransmission number counting result.

Further, when the base station receives the CCA detection result corresponding to the nth subframe and fails, or the base station knows that the UE fails due to CCA detection according to the CCA detection result fed back by the UE, the base station discards the received signal and performs HARQ combining on the uplink data.

According to another aspect of the present invention, there is provided a feedback apparatus for performing clear channel assessment, comprising: a detection module, configured to perform clear channel assessment CCA detection before transmitting uplink data when a user equipment UE is scheduled to transmit the uplink data in an nth subframe of an unlicensed carrier, where n is a natural number; and the feedback module is used for feeding back the detection result of the CCA detection to the base station.

Further, the detection result includes one of: success, failure, feedback module includes: the first feedback unit is used for sending the detection result to the base station through the PUCCH when the CCA detection fails, or sending the detection result to the base station through the resource for sending UCI in the PUSCH; the second feedback unit is used for sending the detection result to the base station through the PUCCH when the CCA detection is successful, or sending the detection result to the base station through the resource for sending UCI in the PUSCH; and the third feedback unit is used for sending the detection result to the base station through the PUCCH when the CCA detection is successful or failed, or sending the detection result to the base station through the resource for sending UCI in the PUSCH.

According to the application, when the User Equipment (UE) is scheduled to send uplink data in the nth subframe, idle channel assessment (CCA) detection is executed before the uplink data is sent, and then the detection result of the CCA detection is fed back to the base station, so that the problem that the retransmission performance of the terminal is reduced due to CCA failure in the LAA system in the related technology is solved, and the base station can clearly know whether the scheduled UE sends the corresponding uplink data in the corresponding subframe or not, so that the base station can clearly know whether the received data is effective data or not, the base station can conveniently use the received data, invalid data is prevented from participating in HARQ combination during retransmission, the actual times of HARQ retransmission are not influenced by the failure of the CCA detection, and the effect of improving the data transmission efficiency is achieved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute a limitation on the application. In the drawings:

fig. 1 is a flowchart of a feedback method of performing clear channel assessment according to an embodiment of the present application;

Fig. 2 is a block diagram of a feedback apparatus performing clear channel assessment according to an embodiment of the present application;

FIG. 3 is an alternative block diagram of the feedback device performing clear channel assessment in accordance with an embodiment of the present application;

FIG. 4 is a schematic diagram of feedback of detection results according to embodiment 1 of the present application;

fig. 5 is a schematic diagram of feedback of detection results based on TDD mode according to embodiment 3 of the present application;

fig. 6 is a basic processing flow at the base station side according to an alternative embodiment of the present application;

fig. 7 is a process flow on the UE side according to an alternative embodiment of the present application.

Detailed Description

The application will be described in detail hereinafter with reference to the drawings in conjunction with embodiments. It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order.

In this embodiment, a feedback method for performing clear channel assessment is provided, fig. 1 is a flowchart of a method for performing feedback for clear channel assessment according to an embodiment of the present application, as shown in fig. 1, where the flowchart includes the following steps:

Step S102, when the user equipment UE is scheduled to send uplink data in an nth subframe of an unlicensed carrier, performing clear channel assessment CCA detection before sending the uplink data, wherein n is a natural number;

step S104, the detection result of the CCA detection is fed back to the base station.

Through the steps, when the User Equipment (UE) is scheduled to send uplink data in the nth subframe, clear Channel Assessment (CCA) detection is executed before the uplink data is sent, and then the detection result of the CCA detection is fed back to the base station, so that the problem that the retransmission performance of the terminal is reduced due to CCA failure in an LAA system in the related technology is solved, and the base station can clearly know whether the scheduled UE sends the corresponding uplink data in the corresponding subframe or not, so that the base station can clearly know whether the data received at this time is effective data or not, the base station can conveniently use the received data, invalid data is prevented from participating in HARQ combination during retransmission, the actual times of HARQ retransmission can be ensured not to be influenced by the failure of the CCA detection, and further the effect of improving the data transmission efficiency is achieved.

In this embodiment, the nth subframe is subframe n, and correspondingly, the 1 st subframe after the nth subframe is subframe n+1, and so on.

Optionally, feeding back the detection result of the CCA detection to the base station at least includes the following ways:

in mode 1, when a UE is scheduled to transmit uplink data in a subframe n, the UE performs CCA detection before uplink data transmission, and if the CCA detection fails (i.e., the UE cannot transmit data using an unlicensed carrier), the UE transmits a CCA detection result to a base station. If the CCA detection is successful (i.e., the UE may transmit data using an unlicensed carrier), the UE does not transmit CCA detection result information to the base station. And when the base station does not receive the CCA detection result feedback information of the UE in the corresponding subframe, the base station considers that the UE CCA detection is successful and sends corresponding uplink data. If the base station receives the CCA detection result sent by the UE as failure, the base station considers that the UE does not send the corresponding uplink data.

In mode 2, when the UE is scheduled to transmit uplink data in subframe n, the UE performs CCA detection before the uplink data is transmitted, and if the CCA detection is successful, the UE transmits a CCA detection result to the base station. If the CCA detection fails, the UE does not send CCA detection result information to the base station. When the base station does not receive the feedback information of the CCA detection result of the UE in the corresponding subframe, the base station considers that the detection of the UE fails and does not send corresponding uplink data.

In mode 3, when the UE is scheduled to transmit uplink data in subframe n, the UE performs CCA detection before uplink data transmission, and the UE transmits the CCA detection result to the base station. Wherein the detection result comprises: success, failure. The base station and UE process reference modes 1 and 2.

In this embodiment, the detection result may be, but is not limited to,: detection success and detection failure. When the detection result is specifically sent to the base station, the detection result may be sent to the base station through a physical uplink control channel PUCCH, or the detection result may be sent to the base station through a resource for sending uplink control information UCI in a physical uplink shared channel PUSCH

Optionally, in the mode 1, the base station and the UE agree to feed back the CCA failure through the uplink PUCCH format 1, or in the mode 2, the base station and the UE agree to feed back the CCA success through the uplink PUCCH format 1. Mode 3, the base station and the UE agree to feed back the result of CCA detection through the uplink PUCCH format 1 a.

In an alternative embodiment according to the present embodiment, the base station determines a resource index different from other UEs or different from other ACKs/NACKs for the UE transmitting PUCCH format 1 or format 1aWherein->Reference is made to the 36.211vd00 protocol. Alternatively, the base station determines different UEs by the difference in minimum CCE index of DCI configured for the different UEs Different, wherein the base station and the UE determine the corresponding +_ according to the minimum CCE index of the scheduled DCI information>

Optionally, the base station and the UE are according toThe rules for calculating the corresponding reception and transmission resources are the same as those specified by the protocol 36.211vd00 of LTE.

In an alternative embodiment according to the present embodiment, the UE sends the feedback information in modes 1, 2, 3 in the subframe corresponding to subframe n or in the first subframe after the corresponding subframe in the grant carrier.

In an alternative embodiment according to this embodiment, when the corresponding subframe in the grant carrier or the first subframe after the corresponding subframe is the downlink subframe, the base station and the UE agree to forward to the first uplink subframe for feedback. In particular, in a scenario in which the primary carrier is time division duplex TDD, a TDD scenario will be described below. When the forward delay occurs, the base station and the UE agree that the UE feeds back the accumulated CCA failure or success times in the mode 1 or the mode 2. When the base station transmits the PDCCH of the uplink grant information in the subframe n-k, the base station and the UE agree that the UE transmits the CCA detection situation before the UE transmits the uplink data in the subframe n or n+1 in the primary carrier.

In an alternative embodiment according to the present embodiment, when the UE determines that the reason why the data of subframe n cannot be transmitted is due to the failure of the corresponding CCA detection, the UE considers that the current retransmission is invalid, and the UE does not count the number of times of the current retransmission within the actual number of times of the retransmission. Or when the base station knows that the data of the UE in the subframe n is not transmitted due to the corresponding CCA detection failure, the base station considers that the retransmission is invalid, and the base station and the UE do not calculate the retransmission times within the retransmission times actually required.

In an alternative embodiment according to the present embodiment, when the base station knows that the data transmission of the UE in subframe n fails due to the corresponding CCA detection, the base station does not perform HARQ combining on the received signals.

From the description of the above embodiments, it will be clear to a person skilled in the art that the method according to the above embodiments may be implemented by means of software plus the necessary general hardware platform, but of course also by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) comprising several instructions for causing a terminal device (which may be a mobile phone, a computer, a server, or a network device, etc.) to perform the method of the various embodiments of the present invention.

The embodiment also provides a feedback device for performing clear channel assessment, which is used for implementing the foregoing embodiments and preferred embodiments, and is not described in detail. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. While the means described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and contemplated.

Fig. 2 is a block diagram of a feedback apparatus for performing clear channel assessment according to an embodiment of the present invention, as shown in fig. 2, the apparatus including:

a detection module 20, configured to perform clear channel assessment CCA detection before transmitting uplink data when the user equipment UE is scheduled to transmit uplink data in an nth subframe of an unlicensed carrier, where n is a natural number;

and the feedback module 22 is configured to feed back a detection result of the CCA detection to the base station.

Fig. 3 is an alternative block diagram of the feedback apparatus for performing clear channel assessment according to an embodiment of the present invention, as shown in fig. 3, the feedback module 22 includes, in addition to all the modules shown in fig. 2:

a first feedback unit 30, configured to send the detection result to a base station through a PUCCH when the CCA detection fails, or send the detection result to the base station through a resource for transmitting UCI in a PUSCH;

a second feedback unit 32, configured to send the detection result to a base station through a PUCCH when the CCA detection is successful, or send the detection result to the base station through a resource for transmitting UCI in a PUSCH;

and a third feedback unit 34, configured to send the detection result to the base station through a PUCCH when the CCA detection is successful or failed, or send the detection result to the base station through a resource for sending UCI in a PUSCH.

It should be noted that the first feedback unit 30, the second feedback unit 32, and the third feedback unit 34 may be disposed in the feedback module 22 at the same time, or one or more of them may be disposed in the feedback module 22.

The following detailed description is of alternative embodiments in accordance with the invention:

the method comprises the following steps:

scheme 1: when the UE is scheduled to transmit in an unlicensed carrier, the UE feeds back information of CCA failure before the scheduled data, including: CCA failed, or CCA was successful. Feedback specifically through PUCCH, including use of: the ACK/NACK may be fed back over an licensed carrier or the unlicensed carrier.

Scheme 2: and the UE feeds back the information of CCA failure before the scheduled data is sent, and when the base station receives the information, the base station considers that the data retransmitted at this time is not sent, and the base station performs HARQ combination on the received data at this time and the received data between the base station and the base station.

Scheme 3: the UE feeds back the information of CCA failure before the scheduled data is sent, the base station and the UE agree that the number of retransmission unsent caused by CCA failure is removed from the configured number of retransmission of the UE, so that the actual number of retransmission meets the configuration requirement. For example, not counting the number of retransmissions of the configuration.

Example 1

Corresponding to mode 1, a feedback CCA detection scenario method for a UE and a base station is described. Fig. 4 is a feedback schematic diagram of the detection result according to embodiment 1 of the present invention, as shown in fig. 4, the detection result is fed back in the nth uplink subframe.

When the base station and the UE agree on feedback CCA detection conditions, specifically, when CCA detection fails, corresponding feedback is carried out. PUCCH format 1 in the existing LTE system is used. The conventional PUCCH format 1 is used to transmit a Scheduling Request (SR), and the base station determines whether or not an SR request is transmitted only by means of energy detection.

If PUCCH format 1 is used to transmit CCA detection failure, then it is assumed that when CCA detection fails, the UE transmits a corresponding feedback signal, where the feedback signal is the same as the SR request, except that the transmitted code resources are different (including the transmitted time-frequency domain resources, etc.). And specifically, acquiring code resources for transmitting the PUCCH format 1 according to the UE special RRC message. Preferably, for the CCA detection case, the transmission period of the SR request is 1ms or 2ms, which facilitates the existence of SR resources available for the UE.

For example, for a UE scheduled in an unlicensed carrier, a corresponding SR request period is configured to be 1ms, and the corresponding SR request resource is requested and transmitted through a dedicated RRC message. Then the SR request resource is used to transmit a CCA detection failure when the corresponding CCA detection of the UE in subframe n fails. When the base station detects an SR request signal on an SR resource corresponding to the authorized carrier of the subframe n, the result shows that the CCA detection of the UE in the subframe n fails.

Obviously, this approach is suitable for the case where the unlicensed carrier does not support the actual SR request, or the case where the UE is not allowed to transmit the SR request in the unlicensed carrier. If the unlicensed carrier supports the transmission of SR requests, then the actual SR request may be caused to collide with CCA detection failure.

In order to avoid this latter case. The optimization scheme is given below:

the base station adds the resource configuration information sent as the CCA detection failure information in the UE special RRC message, so that the actual resource configuration information of the SR request and the resources of the CCA detection failure information are respectively configured, and even if the SR request and the CCA detection failure information are sent in the same subframe, the SR request and the CCA detection failure information can be easily distinguished due to different code resources.

And, a subframe period of the resource of the CCA detection failure information may be configured to be 1ms or 2ms. Namely, the subframe period of the SR request and the subframe period of the resources of the CCA detection failure information are respectively configured.

The information that the corresponding UE feeds back the CCA detection success may also be applicable.

Example 2

Corresponding to mode 3, a feedback CCA detection scenario method for the UE and the base station is described.

When the base station and the UE agree to feed back the CCA detection situation, specifically, when the CCA detection fails, the UE feeds back 1, and when the CCA detection is successful, the UE feeds back 0. The opposite is also possible. Wherein 1 or 0 adopts the coding and transmitting mode of the PUCCH format 1 a. This feedback may correspond to PUCCH format 1a in the existing LTE system, where current format 1a is used to feedback whether the UE correctly receives downlink data.

The base station and the UE agree that the base station configures feedback resources for feeding back CCA detection failure/success information in a subframe n of an authorized carrier corresponding to a corresponding uplink subframe n for the UE scheduled in the unauthorized carrier. When the UE performs CCA detection before transmitting data in a corresponding uplink subframe according to scheduling of the base station, if channel detection fails/succeeds, the UE transmits information of the CCA detection failure or success to the base station in a corresponding subframe of an authorized carrier.

Coding and resource determination of CCA detection failure or success information is performed according to section 5.4 of LTE protocol 36.211vd 00.

Wherein section 5.4 requires a parameter in making the resource determinationThe parameter is based on the corresponding scheduling information (i.e. on transmissionPDCCH of row grant information), the specific estimate is consistent with the existing LTE protocol. Wherein p is E [ p ] ₀ ，p ₁ ]P denotes the antenna port, including ports 0 and 1./>Mapping to port p is PUCCH format 1a. Wherein (1)>nCCE represents the smallest CCE index in the corresponding PDCCH,/-CCE>Configured for higher layer signals. Reference may be made in particular to section 10.1.2.1 of the 36.213vd00 protocol.

The base station and the UE calculate the resources of the CCA failure/success information received and transmitted according to the above-mentioned agreed manner.

To avoid collision with the actual ACK/NACK feedback, the base station needs to configure physical resources or code resources of the actual ACK/NACK differently from those of CCA detection failure/success. Specifically, the minimum index values of CCEs at the time of configuring the respective PDCCH transmissions may be different.

In this embodiment, the resources (including time domain, frequency domain and code resources) used for sending the CCA detection result may also be allocated to the UE through higher layer signaling, for example, using UE-specific RRC message sending.

Example 3

Based on embodiments 1 and 2, when the primary carrier or the grant carrier is in TDD mode, fig. 5 is a schematic diagram of feedback of the detection result based on TDD mode according to embodiment 3 of the present invention, and as shown in fig. 5, the detection result is fed back in the n+1th uplink subframe. At this time, the subframe corresponding to the subframe n (subframe for transmitting uplink data and performing CCA before transmission) in the unlicensed carrier may be downlink, and the UE may not transmit the CCA detection result, and at this time, the CCA detection result needs to be transmitted in the primary carrier along to the first uplink subframe after that, which may possibly cause a problem of missing the feedback opportunity.

If the forward delay occurs, the base station needs to reserve resources in the first uplink subframe after the forward delay according to the mode in the subframe n, and the UE still sends a CCA detection result in the first uplink subframe after the forward delay according to the resources reported by the CCA detection result distributed in the subframe n.

If the forward delay occurs, preferably, the base station and the UE need to agree on a maximum forward delay time, and beyond the maximum forward delay time, no feedback is provided.

If the forward direction occurs, the base station and the UE agree that the UE feedback CCA detection result is a plurality of CCA detection feedback results. The base station and the UE agree that the same resource in the subframe n is used for transmitting in the first uplink subframe after the first CCA detection result, the second CCA detection result, the used resource is the resource immediately after the first CCA detection result, and so on.

If forward occurs, the base station and UE preferably reserve feedback for the number of accumulated CCA detection failures or successes.

For the case that the primary carrier is in TDD mode, the base station preferably calculates in advance that the subframe of the scheduled UE transmitting uplink data in the unlicensed carrier exactly corresponds to the uplink subframe of the primary carrier when the UE scheduling the unlicensed carrier transmits uplink data. Because the uplink and downlink subframes in TDD mode are fixed when configured, the LAA carrier is aligned with the primary carrier subframe, and the interval between the transmission of uplink grant information (information for scheduling UE) and the transmission of uplink data is fixed or configurable, the base station easily determines whether the subframe for transmitting uplink grant information is an uplink subframe in the primary carrier or not after the interval of k subframes.

Example 4

After receiving the CCA detection result fed back by the UE, the base station processes in the following manner, and fig. 6 is a processing flow chart at the base station side according to an alternative embodiment of the present invention, as shown in fig. 6, including:

s601, sending uplink authorization information for an LAA carrier to UE through a PDCCH (or ePDCCH) of a main carrier or the LAA carrier in a subframe n-k;

s602, receiving a CCA detection result reported by UE;

s603, receiving uplink data possibly sent by the UE according to the uplink authorization information;

s604, determining the subsequent processing (including whether to retransmit, whether the received data is valid, whether to count the actual retransmission times, and whether to combine with the data of the previous structure) according to the CCA detection result.

LAA carriers (unlicensed carriers) operate in carrier aggregation with licensed carriers, with subframes aligned.

The base station sends uplink grant information in subframe n-k (k is a positive integer) through the PDCCH (or enhanced PDCCH, i.e. ePDCCH, hereinafter the same) of the primary carrier (grant carrier) or LAA carrier, and schedules the UE to perform uplink data transmission in subframe n of the unlicensed carrier. The base station receives possible uplink data in a subframe n of the unlicensed carrier, and simultaneously receives a CCA detection result reported by the UE before the uplink data is sent in the subframe n of the unlicensed carrier in a subframe corresponding to the main carrier.

When the base station receives that the CCA detection result before the UE reports the uplink data to be sent in the subframe n of the unlicensed carrier is failed (the CCA detection result is that the channel is not idle), the base station considers that the UE does not send the scheduled data in the subframe n. The base station may discard the received uplink data. This retransmission is considered invalid and is not counted as the number of actual retransmissions. The base station does not perform HARQ combining on the uplink data received this time and the uplink data received previously.

When the base station receives the CCA detection result reported by the UE as success (the CCA detection result is that the channel is idle), the base station considers that the UE transmits uplink data according to the uplink authorization information. And considering the received uplink data as effective data, and counting the retransmission into the actual retransmission times.

For the above different CCA result feedback modes, the processing conditions of the base station are different, if the UE only sends the CCA detection result when the CCA fails, the base station receives the CCA detection result, and considers that the UE cannot send uplink data according to the uplink grant information. If the base station does not receive the information of the CCA detection failure (the base station cannot receive the CCA detection result because the UE CCA detection is successful at this time), the base station considers that the UE has transmitted uplink data according to the uplink grant information.

The processing principle is similar for the UE to only feed back the result of the CCA detection success, and will not be described here again.

And for the situation that the UE feeds back not only the information of the CCA detection failure but also the information of the CCA detection success, the base station directly judges according to the received feedback information.

Example 5

Fig. 7 is a flow chart of UE-side processing according to an alternative embodiment of the present invention, for illustrating UE behavior in the present invention, as in fig. 7: comprising the following steps:

s701, receiving uplink authorization information for an LAA carrier sent by a base station through a PDCCH (or ePDCCH) in a subframe n-k;

s702, according to the uplink authorization information, executing CCA detection before the subframe n transmits data;

s703, reporting a CCA detection result;

s704, determining whether to continue transmitting uplink data in subframe n according to the PDCCH according to the CCA detection result.

And the UE receives the PDCCH (or ePDCCH) in the subframe n-k of the main carrier or the LAA carrier to acquire uplink authorization information, and determines to transmit uplink data in the subframe n of the LAA carrier according to the uplink authorization information.

Before the UE transmits uplink data in the subframe n of the LAA carrier, the UE firstly executes CCA detection, and if the channel is idle, the UE transmits corresponding uplink data according to the uplink authorization information. The UE simultaneously transmits the CCA detection result to the base station (the transmission CCA detection result of the UE behaves differently according to the aforementioned modes 1, 2, 3). If the channel is not idle, the UE gives up the uplink data transmission in the subframe n. The CCA detection result is transmitted to the base station at the time of UE (the transmission CCA detection result of UE behaves differently according to the aforementioned modes 1, 2, and 3). The UE considers this scheduling or retransmission as invalid and does not take into account the actual number of retransmissions.

Example 6

As the number of LAA carriers that are simultaneously aggregated by the UE increases, for example, a typical value of 4 LAA carriers, currently, according to the specification of the LTE protocol, a maximum of 32 carrier aggregation is supported, if the number of LAA carriers is at most 31 and these carriers are scheduled to transmit uplink data at the same subframe location, then the UE needs to perform CCA on each carrier separately, then how to feed back CCA detection results of each carrier simultaneously? The present example gives a method.

The transmission mechanism of UCI in the existing LTE system is utilized, including different PUCCH formats (formats 1b, 2a, 2b, 3 and possibly additional formats later) and a transmission mechanism of UCI (uplink control information) transmitted through PUSCH. Specifically (multiple carriers feed back in one PUCCH resource of the same carrier and the same subframe):

taking PUCCH format 2b as an example, assume that the base station configures 21 LAA carrier aggregation for the UE and is scheduled to transmit uplink data at the same time on each carrier in the same subframe. The UE needs to perform CCA detection for 21 carriers, respectively, and report the CCA detection result. At this time, the base station and the UE agree to perform feedback of the CCA detection result using a certain PUCCH format, for example, format 2b. When the base station schedules the UE to transmit uplink data in subframe n, the base station needs to configure corresponding resources in subframe n of the primary carrier according to the mode of allocating resources for PUCCH format 2b in the current LTE system. The UE then performs CCA detection for 21 carriers, and the detection result of each LAA carrier arranges the corresponding CCA detection results (if 1 bit per carrier describes whether CCA detection is successful) in a agreed order (e.g., serving cell index from small to large) to form a bit to be fed back. And then acquiring and transmitting corresponding feedback resources according to the modes of code modulation, sequence selection and resource calculation of the existing PUCCH format 2b. Note that the CCE index value used at this time is the smallest CCE index of the PDCCH of the current uplink scheduling.

The base station estimates the resources used for reporting the CCA detection result according to the CCE index, then decodes and the like, and the base station analyzes the bits in the format 2b according to the CCA detection result agreed in advance.

In the case where the CCA detection result is fed back by multiple carriers in different resources of the same subframe of the same carrier, the above modes 1, 2, and 3 can be used in the same way as the existing resource determination mode in which the ACK/NACK is fed back by multiple carriers in different resources of the same carrier (section 10.1.2.2 of 36.213vd 00).

Example 7

And carrying the CCA detection result in a mode of transmitting UCI by using the existing PUSCH mode. The method comprises the following steps:

the base station and the UE agree that when the subframe n-k transmits the PDCCH to schedule the UE to transmit uplink data in the subframe n of a plurality of unlicensed carriers, the UE needs to perform CCA detection before transmitting the data, and then the result of CCA detection needs to be reported to the base station, preferably in the subframe n of the licensed carriers.

The base station and the UE agree that the resources of subframe n for reporting the CCA detection result are determined by means of the existing PUSCH transmitting UCI (i.e. the resource allocation means when the existing PUSCH transmits UCI (see section 5.2.4 of 36.212vd 00), and the resources are allocated for the CCA detection result feedback). The procedure of determining the resources at this time is determined using CCEs of the PDCCH in subframe n-k (selection and usage of specific CCEs is the same as the existing protocol). And the base station receives a CCA detection result fed back by the UE on the resources appointed according to the rule, and analyzes bits in the CCA detection result according to the CCA detection result.

The application mainly utilizes the existing mechanism that PUCCH or PUSCH is used for UCI transmission, redefines the bit meaning as a CCA detection result, thereby transmitting CCA detection result information to a base station, and the other resources are allocated, encoded, transmitted and the like along with the existing mechanism. In the above embodiments, when determining the resources fed back by the CCA detection result, the CCE of the PDCCH of the uplink grant information of the current uplink scheduling is determined by combining with the parameters of the higher layer signaling, and the determination mode is the same as that of the existing protocol.

Embodiments 1 to 7 can also be said to be transmitting a new information, i.e., CCA detection result of the UE, using the existing PUCCH format (or PUSCH transmitting UCI). The information in the existing PUCCH format (UCI in PUSCH) may be mixed with the information (in mixed transmission, those bits in the information that need to be scheduled in advance are the result of CCA detection), or separate PUCCH resources may be allocated separately for transmission. The latter is preferred.

Example 8

The problem to be solved by this embodiment is different from the first 7 embodiments, but is originally the same as the above-described embodiments. The embodiment provides feedback information of whether the UE transmits data or not under semi-static scheduling.

Problems solved by this example 8: in the LTE system, there is currently Semi-persistent scheduling (SPS, semi-Persistent Scheduling), for example, after the base station transmits the uplink grant information once, the uplink grant information is valid for a long time (before the base station does not transmit the termination information), and the UE transmits uplink data in the corresponding subframe according to the uplink grant information, however, when the UE arrives in the corresponding uplink subframe, the UE sometimes just has no data to transmit, and at this time, in the LTE method, the UE transmits some filled data (invalid data) to ensure the persistence of Semi-persistent scheduling, and if the UE does not transmit data, the Semi-persistent scheduling may be terminated. But this is detrimental to UE power saving and introduces interference to neighboring cells. The problem is even more serious if the transmission interval of the semi-persistent scheduling is further narrowed. In addition, a similar problem may exist for enhanced dynamic scheduling, for example, when the UE uses contention from the resource pool to transmit uplink data under dynamic scheduling, there is a case that the UE contends for the resource but does not transmit data. The scheme of the application can also solve the problem that no data is sent during dynamic scheduling.

In order to overcome the above problems, the present application provides a UE reporting information for describing that the UE has no data to send at this time (or needs to continue to send later). After receiving the information, the base station does not terminate the semi-static scheduling of the UE.

The specific implementation manner of this embodiment is as follows:

when the UE is in semi-static scheduling (uplink grant information has been received before and is valid for a longer period of time), and when the UE does not need uplink data to be transmitted in the corresponding transmission subframe (or opportunity), the UE feeds back reporting information 1 to the base station. Wherein, the information 1 describes that the UE does not send corresponding uplink data at this time. If the UE has data to transmit in the corresponding subframe, the UE may transmit indication information that the UE transmitted the data (the principle is the same as that of transmission information 1, and information 1 is taken as an example).

The base station and the UE agree on resources for the UE to feed back the above information 1, including time domain, frequency domain or code resources, in the corresponding subframes (i.e. subframes scheduled to transmit semi-static data, but subframes without data transmission) in the carriers corresponding to the semi-static data to be transmitted (or the base station and the UE agree on the primary carriers paired with the carriers corresponding to the semi-static data to be transmitted). The information 1 is distinguished from other information by the above-described resources. The specific resource allocation method may adopt a resource allocation method of a PUCCH format of the UE in the existing LTE (including a PUSCH resource allocation method of UCI transmission), including allocation of time domain, frequency domain, or sub-resource, etc. And the same coding mode and mapping mode (including the coding mode and mapping mode for transmitting UCI through PUSCH) as those of the PUCCH format of the UE in the existing LTE are adopted.

Preferably, the information 1 includes 1 bit of information, and is preferably carried in a manner similar to the PUCCH format 1a, including allocation of time-frequency domain and code domain resources, where the base station and the UE agree on resources for transmitting the information 1, and then process the information 1 according to the coding, mapping and scrambling manners of the format 1a, and then transmit the information 1 on the resources allocated by the information 1 (so that the coding, mapping and scrambling manners of the information 1 do not need to be redesigned).

In this embodiment, it can also be said that a new information, i.e., information 1, is transmitted using an existing PUCCH format (or PUSCH transmitting UCI). The information in the existing PUCCH format (UCI in PUSCH) may be mixed for transmission (when mixed for transmission, those bits in the information that need to be transmitted by a priori contract are information 1), or independent PUCCH resources (PUSCH resources including time domain, frequency domain, and sub-resources, one of which may be considered as different from the existing one) may be allocated for transmission. The latter is preferred.

Example 9

For the resources for uplink data transmission to be preempted from the resource pool allocated in advance by the UE from the base station, the present application provides the following way to reduce blind detection at the base station side. For example, the resource pool includes n resource blocks, and the UE needs to compete for one or more from the n resource blocks to transmit uplink data, where the base station needs to perform blind detection to find that the UE uses that resource block to transmit uplink data, which is obviously relatively complex.

The following means are provided in this embodiment:

after competing for resources for uplink data transmission from the resource pool, the UE transmits uplink data, and at the same time, the UE transmits a used resource index to the base station. The resource index is sent to the base station in a PUCCH mode or sent to the base station in a mode of sending UCI in PUSCH. The specific transmission resource index is the same as the information 1 or CCA detection result described above. At this time, the transmission of the present carrier wave is also possible.

Considering that the resource index may exceed 2 bits, the manner of transmitting UCI in PUSCH is preferentially considered.

That is, the base station allocates a resource (including time domain, frequency domain, code domain) for transmitting the resource index in the same manner as for transmitting UCI. Except that the base station and UE now agree on the resource to use for transmission of the resource index. The UE then transmits using the same coding, modulation, scrambling, and mapping transmissions as the existing UCI. The resource index is transmitted by means of UCI transmission, and the base station and the UE agree on the information on the resource as the resource index.

Behavior of the base station: and the base station receives the resource index information sent by the UE and decodes the data in the intercepted corresponding resources according to the resource index.

And the UE transmits uplink data in the preempted resources and transmits a resource index to the base station in the allocated resources.

It should be noted that each of the above modules may be implemented by software or hardware, and for the latter, it may be implemented by, but not limited to: the modules are all located in the same processor; alternatively, the modules are located in a plurality of processors, respectively.

The embodiment of the invention also provides a storage medium. Alternatively, in the present embodiment, the above-described storage medium may be configured to store program code for performing the steps of:

s1, when User Equipment (UE) is scheduled to send uplink data in an nth subframe of an unlicensed carrier, executing Clear Channel Assessment (CCA) detection before sending the uplink data, wherein n is a natural number;

s2, feeding back a detection result of the CCA detection to the base station.

Alternatively, in the present embodiment, the storage medium may include, but is not limited to: a U-disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a removable hard disk, a magnetic disk, or an optical disk, or other various media capable of storing program codes.

Optionally, in this embodiment, the processor performs, according to the program code stored in the storage medium, clear channel assessment CCA detection when the user equipment UE is scheduled to transmit uplink data in an n-th subframe of the unlicensed carrier, before transmitting the uplink data, where n is a natural number;

Optionally, in this embodiment, the processor performs feedback of a detection result of the CCA detection to the base station according to the program code stored in the storage medium.

Alternatively, specific examples in this embodiment may refer to examples described in the foregoing embodiments and optional implementations, and this embodiment is not described herein.

It will be appreciated by those skilled in the art that the modules or steps of the invention described above may be implemented in a general purpose computing device, they may be concentrated on a single computing device, or distributed across a network of computing devices, they may alternatively be implemented in program code executable by computing devices, so that they may be stored in a memory device for execution by computing devices, and in some cases, the steps shown or described may be performed in a different order than that shown or described, or they may be separately fabricated into individual integrated circuit modules, or multiple modules or steps within them may be fabricated into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A feedback method for performing clear channel assessment, comprising:

when User Equipment (UE) is scheduled to send uplink data in an nth subframe of an unlicensed carrier, executing Clear Channel Assessment (CCA) detection before sending the uplink data, wherein n is a natural number;

feeding back a detection result of the CCA detection to a base station;

the method further comprises the steps of: when the detection result is failure, the UE cannot send an nth subframe of uplink data according to the uplink authorization information, the UE considers the retransmission as invalid, and the number of the retransmission is excluded from the actual retransmission number counting result;

the feeding back the detection result of the CCA detection to the base station includes: configuring a corresponding SR request resource in a subframe n of an authorized carrier, and transmitting the SR request resource by the UE under the condition that the CCA detection result is failed, wherein the SR request resource is associated with the CCA detection result; transmitting the CCA detection result in a forward direction under the condition that the subframe n of the authorized carrier is a downlink subframe; and if the CCA detection result is transmitted in a forward direction, the base station and the UE agree to transmit the CCA detection result along the same resource as the nth subframe in the first uplink subframe after the nth subframe.

2. The method of claim 1, wherein the detection result comprises one of: success or failure, and feeding back the detection result of the CCA detection to the base station includes at least one of the following ways:

when the CCA detection fails, the detection result is sent to a base station through a Physical Uplink Control Channel (PUCCH), or the detection result is sent to the base station through a resource for sending Uplink Control Information (UCI) in a Physical Uplink Shared Channel (PUSCH);

when the CCA detection is successful, the detection result is sent to a base station through a PUCCH, or the detection result is sent to the base station through a resource for sending UCI in a PUSCH;

and when the CCA detection is successful or failed, sending the detection result to a base station through a PUCCH, or sending the detection result to the base station through a resource for sending UCI in a PUSCH.

3. The method of claim 2, wherein,

when the CCA detection fails, sending the detection result to a base station through a PUCCH resource, wherein the method comprises the following steps: transmitting the detection result to a base station through a physical uplink control channel PUCCH format 1; and/or

When the CCA detection is successful, sending the detection result to a base station through a PUCCH resource, wherein the method comprises the following steps: transmitting the detection result to a base station through a physical uplink control channel PUCCH format 1;

Wherein the PUCCH format 1 includes at least one of: the same coding scheme, time domain resource allocation scheme, frequency domain resource allocation scheme, code domain resource allocation scheme, and mapping transmission scheme as those of PUCCH format 1.

4. The method of claim 2, wherein,

when the CCA detection is successful or failed, sending the detection result to a base station through a PUCCH resource, wherein the method comprises the following steps: transmitting the detection result to a base station through a PUCCH format 1 a;

wherein the PUCCH format 1a includes at least one of: the same coding scheme, time domain resource allocation scheme, frequency domain resource allocation scheme, code domain resource allocation scheme, and mapping transmission scheme as those of PUCCH format 1 a.

5. The method of claim 3 or 4, wherein,

allocating the detection result and acknowledgement/non-acknowledgement (ACK/NACK) or Scheduling Request (SR) by means of base station and UEResource index of different PUCCH format 1 or PUCCH format 1aOr (b)

Calculating a resource index of the UE in the nth subframe for feeding back the detection result through a CCE with the minimum index number in a Physical Downlink Control Channel (PDCCH) of uplink authorization information carried in the nth subframe or a Control Channel Element (CCE) of an enhanced PDCCH in a mode agreed by a base station and the UE Is a value of (2);

wherein the saidAnd (3) the resource index of the PUCCH format 1 or 1a, wherein k is the number of interval subframes between the uplink authorization information transmission subframe and the corresponding uplink data transmission subframe.

6. The method of claim 5, wherein theAnd calculating time domain, frequency domain and code domain resources of the UE for sending the detection result according to a protocol LTE TS 36.211vd 00.

7. The method of claim 1, wherein feeding back the detection result of the CCA detection to the base station comprises: and feeding back a detection result of the CCA detection to the base station in a subframe corresponding to the nth subframe or a first subframe after the corresponding subframe in the authorized carrier.

8. The method of claim 7, wherein when the subframe corresponding to the nth subframe in the grant carrier is a downlink subframe, a detection result of the CCA detection is fed back to the base station in a 1 st uplink subframe after the subframe corresponding to the nth subframe in the grant carrier in a manner agreed by the base station and the UE, and/or when the 1 st subframe after the subframe corresponding to the nth subframe in the grant carrier is a downlink subframe, a detection result of the CCA detection is fed back to the base station in a 1 st uplink subframe after the 1 st subframe after the subframe corresponding to the nth subframe in the grant carrier in a manner agreed by the base station and the UE.

9. The method of claim 8, wherein when the base station and the UE agree on a 1 st uplink subframe after an nth subframe or a 1 st uplink subframe after a 1 st subframe after an nth subframe feedback the detection result of the CCA detection to the base station, the detection result further includes a number of CCA failures or successes accumulated by the UE.

10. The method of claim 1 wherein when the base station transmits the PDCCH or enhanced PDCCH of the uplink grant information in the n-k th subframe, the detection result is fed back to the base station in the n-th or n+1-th subframe of the primary carrier by means agreed by the base station and the UE, wherein k is a number of subframes between the uplink grant information transmission subframe and the corresponding uplink data transmission subframe.

11. The method of claim 1, wherein when the base station receives a CCA detection result corresponding to the nth subframe and fails, or the base station knows that the UE fails due to CCA detection according to the CCA detection result fed back by the UE, the base station excludes the number of retransmissions from the actual retransmission number counting result.

12. The method of claim 1, wherein when the base station receives a CCA detection result corresponding to the nth subframe and fails, or the base station learns that the UE fails due to CCA detection according to the CCA detection result fed back by the UE, the base station discards the received signal to perform HARQ combining of the uplink data.

13. A feedback apparatus for performing clear channel assessment, comprising:

a detection module, configured to perform clear channel assessment CCA detection before transmitting uplink data when a user equipment UE is scheduled to transmit the uplink data in an nth subframe of an unlicensed carrier, where n is a natural number;

the feedback module is used for feeding back the detection result of the CCA detection to the base station;

the device is further configured to, when the detection result is failure, enable the UE to send an nth subframe of uplink data according to the uplink grant information, enable the UE to consider the retransmission as invalid, and exclude the number of the retransmission from the actual retransmission number counting result;

14. The apparatus of claim 13, wherein the detection result comprises one of: success, failure, feedback module includes:

the first feedback unit is used for sending the detection result to the base station through the PUCCH when the CCA detection fails, or sending the detection result to the base station through the resource for sending UCI in the PUSCH;

the second feedback unit is used for sending the detection result to the base station through the PUCCH when the CCA detection is successful, or sending the detection result to the base station through the resource for sending UCI in the PUSCH;

and the third feedback unit is used for sending the detection result to the base station through the PUCCH when the CCA detection is successful or failed, or sending the detection result to the base station through the resource for sending UCI in the PUSCH.