CN107889113B

CN107889113B - Method and device for monitoring carrier wave and transmitting signal in unlicensed frequency band

Info

Publication number: CN107889113B
Application number: CN201610875351.6A
Authority: CN
Inventors: 王轶; 李琪; 李迎阳; 张世昌
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2016-09-30
Filing date: 2016-09-30
Publication date: 2024-03-29
Anticipated expiration: 2036-09-30
Also published as: CN107889113A

Abstract

The application discloses a signal transmitting method on an unlicensed frequency band, comprising the following steps: the transmitting node monitors a first type carrier wave in the direction i; after the first type carrier wave monitoring is passed, the transmitting node starts signal transmission in the transmitting direction j; wherein the direction i is omni-directional or a single or multiple beam directions corresponding to direction j. By the application of the method and the device, the device and the system, the signal transmission and carrier monitoring of the high frequency band can be adapted, and interference to other nodes on the unlicensed frequency band is avoided.

Description

Method and device for monitoring carrier wave and transmitting signal in unlicensed frequency band

Technical Field

The present application relates to the field of mobile communications technologies, and in particular, to a method and apparatus for carrier monitoring and signal transmission in an unlicensed frequency band.

Background

With the increasing explosion of user demand for high-bandwidth wireless services and the increasing contradiction between scarce spectrum resources, mobile operators are beginning to consider unlicensed bands (also known as unlicensed bands) as a complement to licensed bands. The 3GPP has begun to study how to effectively improve the utilization rate of the whole network spectrum on the premise of ensuring that other technologies of the unlicensed band are not affected obviously by effective carrier aggregation of the unlicensed band and the licensed band by deploying LTE on the unlicensed band (the LTE system deployed on the unlicensed band is referred to as a licensed carrier assisted access LAA system). To support more flexible networking, unlicensed and licensed bands are also very well studied to work by way of dual connectivity (DC, dual connectivity). As shown in fig. 1, two enbs serve the UE at the same time, one is a master eNB (MeNB) providing greater coverage over licensed band carriers and the other is a secondary eNB providing hot spot service over unlicensed band carriers, as shown in fig. 1.

Unlicensed bands have generally been allocated for some other use, for example, radar or wireless fidelity of the 802.11 family (WiFi, wireless Fidelity). In the unlicensed band, how to avoid interference between the LAA system and other wireless systems such as radar or WiFi is a key issue. Carrier sensing (CCA) is a collision avoidance mechanism commonly employed on unlicensed bands. A mobile Station (STA) must detect a radio channel before transmitting a signal and can occupy the radio channel only if it is detected to be idle, a listen-before-talk mechanism called LBT (Listen before talk). LAA also needs to follow LBT mechanism for energy detection of the channel. Typically, the transmit or receive antennas of the enbs or UEs in LAA systems are omni-directional antennas, or wide angle directional antennas. Thus, whether transmitted or LBT is generally considered omni-directional.

With the rapid development of information industry, especially from the growing demands of mobile internet and internet of things, the future mobile communication technology is challenged unprecedented. To address this unprecedented challenge, the communications industry and academia have developed a wide range of fifth generation mobile communication technology research (5G), oriented in the 2020 s. The 3GPP has also begun standardization work for 5G (New radio, NR). NR systems are expected to operate in low frequency bands, up to around 100G, on high frequency band resources, including licensed and unlicensed bands. The unlicensed frequency band mainly considers the 5GHz frequency band and the 60GHz frequency band. In the 60GHz band, in order to compensate for extremely high path loss, massive MIMO based antenna arrays is often used for beamforming (beamforming) to obtain gain. The transmission with directivity is adopted on the unlicensed frequency band, so that the interference among the transmitting nodes in different directions can be effectively reduced, and meanwhile, the special problem of directivity is introduced. The LBT mechanism of the transmitting node and the transmitting signal mode of the transmitting node all need to be correspondingly adjusted based on the characteristics of directivity so as to obtain the maximum gain, and meanwhile, interference to other nodes in an unlicensed frequency band is avoided.

Disclosure of Invention

The method and the device for monitoring the carrier wave and sending the signal on the unlicensed frequency band can adapt to the signal transmission and the carrier wave monitoring of the high frequency band, and avoid the interference to other nodes on the unlicensed frequency band.

In order to achieve the above purpose, the present application adopts the following technical scheme:

a method of signaling over an unlicensed frequency band, comprising:

the transmitting node monitors a first type carrier wave in the direction i;

after the first type carrier wave monitoring is passed, the transmitting node starts signal transmission in the transmitting direction j; wherein the direction i is omni-directional or a single or multiple beam directions corresponding to the transmission direction j.

Preferably, the plurality of beam directions are a predefined beam direction group, or the plurality of beam directions are a set of a plurality of beam directions including at least the beam direction j with reference to the beam direction j.

Preferably, when the transmitting node needs to continuously transmit signals in multiple directions in one transmission burst, the monitoring of the first type of carrier in the direction i includes:

for each of a plurality of transmission directions j, performing a first type of carrier monitoring in a corresponding direction i; or the transmitting node monitors the first type of omni-directional carrier wave.

Preferably, when the transmitting node needs to transmit signals in multiple directions within one transmission burst, the monitoring of the first type of carrier in the direction i includes:

for each of a plurality of transmission directions j, performing a first type of carrier monitoring in a corresponding direction i; or the sending node monitors the first type of omni-directional carrier waves;

the method comprises the following steps: for the direction in which the signal is not directly transmitted after the first-class carrier monitoring, the transmitting node monitors the second-class carrier in the corresponding direction before transmitting the signal in the corresponding direction, and transmits the signal in the corresponding direction after the second-class carrier is monitored; or, for the direction in which the signal is not directly transmitted after the first-type carrier monitoring, if the signal is started to be transmitted within the first set time after the first-type carrier monitoring, before the signal is started to be transmitted, monitoring the second-type carrier in the corresponding direction, and after the second-type carrier monitoring, starting signal transmission in the corresponding direction;

wherein the second type carrier monitoring time is shorter than the first type carrier monitoring time.

Preferably, the sending node performs the first type carrier monitoring in a plurality of corresponding directions i at the same time, and the method further includes:

In the multiple corresponding directions i, for a beam direction k monitored by a first type carrier wave in time, in a set time before the first type carrier wave monitoring is completed in other beam directions, third type carrier wave monitoring is carried out in the direction k, and after the third type carrier wave monitoring is carried out in the direction k, signal transmission is started in a direction j corresponding to the direction k; wherein the third type of carrier monitoring time is shorter than the first type of carrier monitoring time;

or,

adopting the same competition window CWS for a plurality of corresponding directions i for simultaneously carrying out the first type carrier monitoring;

or,

for a plurality of corresponding directions i for simultaneously carrying out the first type carrier monitoring, adopting the same random back-off factors;

or,

for a plurality of corresponding directions i for which the first type carrier monitoring is performed simultaneously, respective random back-off factors are generated in different directions respectively.

Preferably, the transmitting node is a base station, and the starting signal transmission in the transmitting direction j includes: and starting to transmit the discovered signal DRS in the transmitting direction j to be DRS.

Preferably, when the base station transmits the DRS, the base station transmits the DRS of each direction in the DMTC window; wherein the transmission position of the DRS in each direction within the DMTC window is fixed.

Preferably, the method comprises the steps of,

when the carrier monitoring by the base station is omni-directional carrier monitoring,

the sending node performing first-type carrier monitoring in the direction i includes: the base station starts to monitor the omni-directional carrier wave before the first DRS starting point in the DMTC window; the step of starting signal transmission in the direction j by the transmitting node after the first type carrier monitoring is passed comprises the following steps: in the DMTC window, when the carrier wave monitoring is not passed, DRS transmission is not carried out, the DRS in the corresponding direction is transmitted from the earliest DRS transmission position after the omni-directional carrier wave monitoring, and the rest DRS in the DMTC window is continuously transmitted;

and/or the number of the groups of groups,

when the carrier monitoring by the base station is directional carrier monitoring,

the sending node performing first-type carrier monitoring in the direction i includes: and the base station monitors the carrier wave in the corresponding direction before each DRS transmitting position in the DMTC window, if the carrier wave is not monitored, the DRS in the corresponding direction is not transmitted, and if the carrier wave is monitored, the DRS in the corresponding direction is transmitted.

Preferably, when the base station transmits the DRS, the base station transmits the DRS of each direction in the DMTC window; wherein, the transmission sequence of the DRSs in each direction in the DMTC window is fixed, and the starting point position is not fixed.

Preferably, the method comprises the steps of,

the sending node performing first-type carrier monitoring in the direction i includes: the base station monitors the carrier wave before the possible starting point of the first DRS in the DMTC window, and when the carrier wave does not pass the carrier wave monitoring, the base station monitors the carrier wave before the possible starting point of the next DRS in sequence until the carrier wave monitoring is passed; the step of starting signal transmission in the direction j by the transmitting node after the first type carrier monitoring is passed comprises the following steps: within the DMTC window, after monitoring by the carrier, transmitting DRSs in a first direction from the earliest possible DRS after monitoring by the carrier, and continuously transmitting DRSs in all directions within the DMTC window;

and/or the number of the groups of groups,

the sending node performing first-type carrier monitoring in the direction i includes: in the DMTC window, sequentially monitoring carriers in all directions according to the transmission sequence of DRS in all directions; the base station performing carrier monitoring in each direction includes: carrying out carrier monitoring before a possible starting point of the DRS in each direction, and when the carrier monitoring is not passed, carrying out carrier monitoring before the next possible starting point of the DRS in the direction in sequence until the carrier monitoring is passed; the step of starting signal transmission in the direction j by the transmitting node after the first type carrier monitoring is passed comprises the following steps: when the carrier wave monitoring in one direction is passed, the base station starts to send the DRS in the corresponding direction from the possible starting point position of the DRS in the earliest corresponding direction after the carrier wave monitoring is passed.

Preferably, when the base station transmits the DRS, the base station transmits the DRS of each direction in the DMTC window; and when the transmission sequence and the starting point position of the DRS in each direction in the DMTC window are not fixed, carrying the direction information of the DRS when the DRS is transmitted.

Preferably, when the base station supports carrier monitoring in multiple directions at the same time, the base station transmitting the DRS in the direction monitored by the carrier comprises: the base station simultaneously transmits DRSs in multiple directions monitored by carriers.

Preferably, the base station pre-configures the number of directional DRSs; and/or the base station independently configures the transmission period for the DRS in different directions.

Preferably, the signals transmitted in a plurality of directions are beam measurement signals;

when the beam measurement signal is transmitted together with the data signal, the first type carrier monitoring is performed according to the carrier monitoring used for transmitting the data;

when only the beam measurement signal is transmitted, the first type carrier monitoring time is shorter than the carrier monitoring time used for transmitting data.

A method of carrier monitoring over unlicensed bands, comprising:

the method comprises the steps that a transmitting node determines a reference subframe for monitoring a current subframe carrier according to the transmitting direction of the current subframe;

And the sending node adjusts the length of a contention window for carrier monitoring of the current subframe according to the acknowledgement information/non-acknowledgement information ACK/NACK statistical result of the reference subframe, and monitors the carrier of the current subframe.

Preferably, the reference subframe determined according to the transmission direction is: the transmitting node has received the ACK/NACK information and designates a first subframe of a transmission burst transmitted in a direction j 'corresponding to the transmitting direction i'; wherein the designated transmission burst is the transmission burst closest to the current subframe and including the signal in the transmission direction ij ', and the direction j ' is a single or multiple beam directions corresponding to the direction i ';

and/or if the transmission directions of the current subframe are multiple, determining the reference subframe according to the transmission directions as follows: the transmitting node has received the ACK/NACK information and includes at least a subframe of a transmission signal of one of the transmission directions.

Preferably, the plurality of beam directions are a predefined beam direction group, or the plurality of beam directions are a set of a plurality of beam directions including at least one reference beam direction with reference to the one beam direction.

Preferably, the adjusting the contention window length of the carrier monitoring of the current subframe includes:

And counting the ACK/NACK transmitted in the direction j' in the reference subframe, and adjusting the length of the contention window according to the counting result.

Preferably, before determining the reference subframe, the method includes:

receiving a high-level configuration, and if the high-level configuration determines a reference subframe and counts ACK/NACK according to a sending direction, executing the processing of the reference subframe; otherwise, the process is ended.

A method of carrier monitoring over unlicensed bands, comprising:

and the first sending node determines a Listen Before Transmit (LBT) type indication sent to the second sending node according to the direction of the signal sent by the first sending node and/or the direction of carrier monitoring and the direction of the signal sent by the second sending node, and sends the LBT type indication for the second sending node to monitor the carrier on an unauthorized frequency band.

Preferably, the determining the LBT type indication according to the direction of the signal transmitted by the first transmitting node and the direction of the signal transmitted by the second transmitting node includes:

if the direction im of the signal sent by the first sending node corresponds to the direction jn of the signal sent by the second sending node and the signal sent by the second sending node is in MCOT, determining that the LBT type indication is an indication of 25us LBT; otherwise, determining the LBT type indication as an indication for Cat-4 LBT; the direction nj is a single beam direction corresponding to the direction im one by one, or the direction jn is one beam direction of a plurality of beam directions corresponding to the direction im.

Preferably, the determining the LBT type indication according to the direction of carrier monitoring of the first transmitting node and the direction of the transmission signal of the second transmitting node includes:

if the direction of carrier monitoring before the first sending node sends the signal is omnidirectional carrier monitoring and the signal of the second sending node is sent in the MCOT, or if the direction im' of carrier monitoring before the first sending node sends the signal corresponds to the direction jn of the signal sent by the second sending node and the signal of the second sending node is sent in the MCOT, determining that the LBT type indication is an indication of 25us LBT; otherwise, determining the LBT type indication as an indication for Cat-4 LBT; the direction jn is a single beam direction corresponding to the direction m 'i one by one, or the direction jn is one beam direction of a plurality of beam directions corresponding to the direction m' i.

Preferably, when the first transmitting node is a base station and the second transmitting node is a terminal UE, the transmitting the LBT type indication includes:

and carrying the LBT type indication through uplink scheduling information of the scheduling UE, or carrying the LBT type indication through downlink cell common signaling.

Preferably, when the LBT type indicates that the signal is carried through the cell common signaling, the cell common signaling carries direction information of the signal sent by the first sending node or direction information of carrier monitoring before the signal is sent by the first sending node.

A signaling device over an unlicensed band, comprising: a carrier monitoring unit and a signal transmitting unit;

the carrier monitoring unit is used for monitoring a first type of carrier in the direction i and notifying the signal transmitting unit after monitoring the first type of carrier;

the signal transmitting unit is used for starting signal transmission in the transmitting direction j after receiving the notification of the carrier monitoring unit; wherein the direction i is omni-directional or a single or multiple beam directions corresponding to direction j.

A carrier monitoring device on an unlicensed frequency band, comprising: a reference subframe determining unit and a carrier monitoring unit;

the reference subframe determining unit is used for determining a reference subframe for monitoring the current subframe carrier according to the sending direction of the current subframe;

the carrier monitoring unit is configured to adjust a contention window length of carrier monitoring of the current subframe according to an ACK/NACK statistics result of the reference subframe, and perform carrier monitoring of the current subframe.

A first transmitting node device on an unlicensed frequency band, comprising: an LBT type indication determining unit and an LBT type indication transmitting unit;

the LBT type indication determining unit is configured to determine an LBT type indication sent to the second sending node according to the direction of the signal sent by the first sending node and/or the direction of carrier monitoring, and the direction of the signal sent by the scheduled second sending node;

the LBT type indication sending unit is used for sending the LBT type indication and used for the second sending node to monitor the carrier wave on the unlicensed frequency band.

According to the technical scheme, in the method, when the carrier monitoring is performed before signal transmission, the directional carrier monitoring is performed, so that interference to other nodes of an unlicensed frequency band is avoided, and the system gain is improved.

Drawings

FIG. 1 is a diagram of a dual connectivity network deployment scenario for an licensed band and an unlicensed band;

FIG. 2 is a schematic flow chart of the method of example 1 in the present application;

fig. 3 is a schematic diagram of carrier monitoring and signaling in embodiment 1;

fig. 4 is a second schematic diagram of carrier monitoring and signaling in embodiment 1;

fig. 5 is a schematic diagram of carrier monitoring performed by the eNB in embodiment 1 in two beam directions simultaneously;

Fig. 6 is a schematic diagram one of determining a reference subframe in embodiment 2;

fig. 7 is a diagram two of determining a reference subframe in embodiment 2;

fig. 8 is a diagram III of determining a reference subframe in embodiment 2;

fig. 9 is a schematic diagram of a base station scheduling UE to transmit uplink and downlink service data in embodiment 3;

fig. 10 is a schematic diagram of transmitting DRS in embodiment 4;

fig. 11 is a schematic diagram two of DRS transmission in embodiment 4;

fig. 12 is a diagram illustrating a possible starting point position of the DRS in embodiment 4;

fig. 13 is a diagram showing a second possible starting point position of the DRS in embodiment 4;

fig. 14 is a diagram III of a transmission drS in embodiment 4;

fig. 15 is a diagram showing transmission of DRS in embodiment 4;

fig. 16 is a basic structural diagram of a signal transmission device corresponding to embodiment 1;

fig. 17 is a basic structural diagram of a carrier monitoring device corresponding to embodiment 2;

fig. 18 is a basic structural diagram of a first transmitting node apparatus corresponding to embodiment 3;

fig. 19 is a basic structural diagram of a second transmitting node apparatus corresponding to embodiment 3;

fig. 20 is a basic structural diagram of a signal transmission device corresponding to embodiment 4.

Detailed Description

In order to make the objects, technical means and advantages of the present application more apparent, the present application is further described in detail below with reference to the accompanying drawings.

For the purposes of making the objects, technical solutions and advantages of the present application more apparent, the present application will be described in further detail below with reference to the accompanying drawings and examples.

Example 1:

in this embodiment, before signal transmission is performed on the unlicensed band, carrier monitoring is performed with respect to the signal transmission direction. Specifically, the signal method in this embodiment is shown in fig. 2, and specifically includes:

step 101: the transmitting node performs a first type of carrier monitoring (first type CCA) for direction i.

The direction i may be omni-directional or a fixed sector direction.

Wherein omni-directional means not distinguishing directivity. The direction i is a single or multiple beam (beam) direction corresponding to the direction j of the transmitted signal. Here, the plurality of beam directions may be a predefined beam direction group, or may be a set of a plurality of beam directions including at least one reference beam direction with respect to the one beam direction. Here, it is explained that carrier monitoring is achieved by listening to the reception channel, and thus, the direction of reception beam is involved in carrier monitoring.

Preferably, the correspondence of direction i to direction j is predefined, or configured. Note that the number of reception beams may be the same as or different from the number of transmission beams for a certain transmission node. For example, it is possible that the number of receive beams is less than the number of transmit beams, and the width of each receive beam is wider. For example, the receive beam of direction i corresponds one-to-one with the transmit beam of direction j, i.e., the direction is exactly on. For another example, there are a total of 4 receiving beams and a total of 16 sending beams. Then one receiving beam corresponds to 4 sending beams. Then the receive beam of direction i is the transmit beam of direction j.

For example, the eNB supports 16 directional beams as a transmitting node, and the relationship between the direction i and the 16 directional beams and the direction j may be: (1) direction i is 1 of the 16 beams. (2) The direction i may also be the direction corresponding to 1 group of the N groups of beams. For example, the 16 beams may be equally divided into N groups, e.g., n=4, then the 1 st to 4 th beams are the first group, the 5 th to 8 th beams are the second group, and so on. The direction i is one of the N groups of beams. The set of beams contains the beam direction of direction j. (3) The direction i may also be the direction of a beam group consisting of M adjacent beams comprising the direction j. M is predefined or configured. For example, assuming that each reception beam group is set to 3 beams, the direction i is the direction corresponding to the beam group consisting of the beams of the direction j-1, the direction j, and the direction j+1.

Preferably, for the case of (2) or (3), the transmitting node may perform CCA detection in the combined direction i corresponding to the beam group, for example, if the transmission beam width is 20 degrees, and if four receiving beams are predefined or configured as a group, the receiving beam width is 80 degrees, and the transmitting node performs CCA detection in the direction i with the width of 80 degrees. The transmitting node may also perform CCA detection in a plurality of smaller directions i corresponding to the beam group, for example, if the transmission beam width is 20 degrees, four receiving beams are predefined or configured as a group, and the receiving beam width is 40 degrees, and to perform CCA detection in a direction i with a width of 80 degrees, the transmitting node may perform CCA detection in two directions i with a width of 40 degrees, respectively.

In addition, it is explained here that the direction i and the direction j are corresponding to each other, and in some cases, it is possible to determine the signal transmission direction j first, and then determine the carrier monitoring direction i according to the direction j; in some scenarios, it is possible to determine the direction i of carrier monitoring first, then determine the corresponding signal transmission direction j corresponding to the direction i of carrier monitoring, and then perform signal transmission in that direction. In the following description, the direction i is referred to as a carrier monitoring direction, and the direction j is referred to as a signal transmission direction.

Step 102: if the first type carrier monitoring of direction i passes, the transmitting node may start transmitting signals in the corresponding direction j.

The first type of carrier monitoring in this embodiment may be a predefined carrier monitoring method. Preferably, the first type of carrier monitoring may be Category-4LBT in existing LAA systems. See in particular the description in section 15 TS 36.213.

Preferably, after the first type carrier monitoring is completed in the direction i, the transmitting node may immediately start to transmit signals in the direction j corresponding to the direction i. The correspondence is as described in step 101.

In this embodiment, the transmitting node may be a base station or a terminal device. In the following description, a transmitting node is described as a base station.

Preferably, if the transmitting node is to continuously transmit signals in multiple directions in one transmission burst (e.g. downlink burst), the transmitting node needs to monitor at least in the carrier monitoring directions i corresponding to all the transmitting directions by the first type of carrier. For the transmission direction corresponding to the direction monitored by the carrier, signal transmission can be performed in the downlink burst. For example, mcot=4ms, and the enb is to transmit downlink data in direction 1 in the 1 st and 2 nd subframes and downlink data in direction 2 in the 3 rd and 4 th subframes. Then, the eNB needs to complete the first type carrier monitoring in the carrier monitoring direction i corresponding to the direction 1 and the direction 2 before the 1 st subframe, so as to start sending the 1 st to 4 th subframes, and the eNB in the 4 subframes does not need to perform the first type or other carrier monitoring. If the carrier monitoring directions i corresponding to the direction 1 and the direction 2 overlap, the carrier monitoring may be performed once in the overlapping direction.

Alternatively, preferably, if the transmitting node is to continuously transmit signals in multiple directions in one transmission burst (for example, downlink burst), the transmitting node may further perform omni-directional carrier monitoring of the first type, that is, carrier monitoring of the first type without distinguishing the directionality, and may transmit signals in a transmitting direction corresponding to the direction passing through the carrier monitoring.

Preferably, if the transmitting node is to transmit signals in multiple directions in one transmission burst (e.g., a downlink burst), the transmitting node needs to perform carrier monitoring of the first type including the carrier monitoring direction i corresponding to all the signal directions to be transmitted. For the direction in which the signal is not transmitted immediately after the first type carrier monitoring is completed, if the transmitting node transmits the signal in the direction after a period of time, the second type carrier monitoring may be performed in the carrier monitoring direction i corresponding to the transmitting direction. If the second type carrier monitoring is successful, the signal can be immediately sent in the corresponding direction. Specifically, the second type carrier monitoring may have time limitation, that is, signal transmission is performed within a set time after the first type carrier monitoring, the second type carrier monitoring may be performed, and if the signal transmission is performed beyond the set time, the first type carrier monitoring needs to be performed again. Alternatively, the second type carrier monitoring may be performed without time limitation, so long as the corresponding monitoring direction is monitored by the first type carrier, the second type carrier monitoring may be performed whenever the signal is transmitted, and the signal is transmitted after being monitored by the second type carrier. The second type of carrier monitoring is a carrier monitoring mode which is predefined and different from the first type of carrier monitoring, and the second type of carrier monitoring is faster than the first type of carrier monitoring. For example, the second type of carrier monitoring only needs to perform LBT within one time unit Td. If the channel is idle for some or all of the time in said time unit Td, the second type carrier monitoring is considered successful.

Preferably, said time unit Td comprises a fixed time Tf and m consecutive monitoring time slots Ts.

For example tf=16us, ts=9us, m is related to the traffic type. Here m is the same as m used in the first type of carrier monitoring.

Preferably, m=1. For example, the time unit Td is 25us, i.e. tf+ts.

For example, mcot=6ms, and enb transmits downlink data in direction 1 in the n+4 th to n+5 th subframes and downlink data in direction 2 in the n+3 th to n+3 th subframes. The eNB is assumed to complete the first type carrier monitoring in the carrier monitoring direction i corresponding to the direction 1 and the direction 2, and then immediately transmits the downlink data of the direction 1 in the n-n+3 subframes. Before the n+4 and n+5 subframes transmit the downlink data in the direction 2, the eNB also needs to perform the second type carrier monitoring on the carrier monitoring direction corresponding to the direction 2. If the second type carrier monitoring is successful, the second type carrier monitoring can be transmitted, otherwise, the second type carrier monitoring cannot be transmitted. As shown in fig. 3.

For another example, the eNB performs the first type of carrier monitoring in the carrier monitoring directions corresponding to the beam direction 1 and the beam direction 2, and successfully monitors the carrier in the carrier monitoring directions corresponding to the two beam directions. The eNB immediately starts transmitting downlink transmission for UE1 in beam direction 1, and continuously transmits from subframe n to subframe n+3. Subsequently, the eNB is to send downlink transmissions, e.g. C-PDCCH, for UE1 and UE2 in beam direction 1 and beam direction 2, respectively, in subframe n+4. Since the eNB has successfully completed Cat-4LBT for beam direction 2 before starting transmission, the eNB only needs to perform fast carrier monitoring in the carrier monitoring direction corresponding to beam direction 2 in Td time unit before subframe n+4 starts transmitting signals in beam direction 2. If the channel is idle, the transmission of signals in beam direction 2 may begin. Further, since the carrier monitoring is performed before the subframe n+4, the signal transmission in the beam direction 1 is suspended, but since the eNB transmits continuous downlink signals in the beam direction 1 in the subframes n to n+3, the eNB does not transmit all downlink signals of the UE1, and the continuously transmitted downlink subframes do not exceed the MCOT, the eNB can perform fast carrier monitoring in the carrier monitoring direction corresponding to the beam direction 1 before the subframe n+4 starts to transmit. If the channel is idle, the transmission of signals in beam direction 1 may begin to continue. As shown in fig. 4.

Alternatively, preferably, if the transmitting node is to transmit signals in multiple directions in one transmission burst (e.g., downlink burst), the transmitting node may perform omni-directional carrier monitoring of the first type, i.e., carrier monitoring of the first type that does not distinguish between directivities. For the signal that is not transmitted immediately after the first type carrier monitoring is completed, if the transmitting node is to transmit the signals in the directions included in the multiple directions after a period of time, the transmitting node needs to perform omnidirectional or second type carrier monitoring in the carrier monitoring direction corresponding to the transmitting direction before transmitting.

Preferably, when the transmitting node monitors the first type of carrier in multiple beam directions, the transmitting node may monitor the first type of carrier in the corresponding beam directions in a time division manner. For example, in the above example, the eNB may perform carrier monitoring on the carrier monitoring direction corresponding to the beam direction 2 first, and then perform carrier monitoring on the carrier monitoring direction corresponding to the beam direction 1. When the transmitting node has multiple antenna arrays, the transmitting node may perform carrier monitoring in multiple beam directions simultaneously. As shown in fig. 5, the eNB, as a transmitting node, supports two antenna arrays, i.e. two radio frequency branches may operate simultaneously at the same time, for example, may perform carrier monitoring in two beam directions simultaneously.

Preferably, when the transmitting node performs carrier monitoring in multiple beam directions at the same time, it is necessary to avoid that a transmitting channel corresponding to the beam direction in which carrier monitoring is completed earlier affects carrier monitoring in the beam direction in which carrier monitoring is still performed. Then the first time period of the first time period,

beam direction i where carrier monitoring is done first, may wait for a period of time before the other beam direction k will be done, and then perform a third type of carrier monitoring in beam direction i. If the third type of carrier is used for monitoring, a signal can be sent in a signal sending direction j corresponding to the beam direction i. This allows carrier monitoring in multiple beam directions to end at the same time, so that signals can start to be transmitted at the same time. Wherein the third type of carrier monitoring is a predefined carrier monitoring mode different from the first type of carrier monitoring, and the third type of carrier monitoring is faster than the first type of carrier monitoring. For example, the third type of carrier monitoring may be considered successful by only detecting that the channel is idle for Td time. The third type of carrier monitoring may be the same as the second type of carrier monitoring or may be different depending on the implementation.

Multiple beam directions for simultaneous carrier monitoring, the same contention window CWS may be used, e.g. the largest CWS of all beam directions for simultaneous carrier monitoring is chosen.

-a plurality of beam directions for simultaneous carrier monitoring, wherein the CWS for each beam direction can be selected based on the LBT priority type beam direction, respectively.

Multiple beam directions for simultaneous carrier monitoring, the same random back-off factor (back off counter) may be employed in the multiple beam directions.

-a plurality of beam directions for simultaneous carrier monitoring, a random back-off factor (back off counter) may be generated in each of the plurality of beam directions.

Preferably, the transmitting node in this embodiment may be a base station, or may be an end user.

Example 2:

in the existing LAA system, the eNB may need to adjust the size of a Contention Window (CWS) when performing carrier monitoring, and when adjusting the CWS size, it is required to determine a reference subframe and adjust the CWS size according to the ACK/NACK statistics result of the reference subframe. In high-band communications, since downlink transmissions are typically beam-based, the various beam directions reflect, to some extent, different geographic locations. Often UEs with widely different beam directions are far apart and are subject to different sources of interference. Therefore, by adjusting the CWS size according to the ACK/NACK of the corresponding beam direction, the influence of the interference received in a certain beam direction on the next transmission in the beam direction can be more truly reflected. However, as described above, in the existing LAA system, the statistics of ACK/NACK of the reference subframe is not determined according to the positional relationship of the UE.

In this embodiment, the CWS size is adjusted according to the ACK/NACK statistics corresponding to the beam direction. Specifically, the method for carrier monitoring in the unlicensed band in this embodiment includes,

step 201: and corresponding to the current subframe needing carrier monitoring, the transmitting node determines a reference subframe according to the transmitting direction of the current subframe.

The transmitting node determines a reference subframe k according to the transmitting direction i' of the subframe to be transmitted currently.

Specifically, subframe k may be the first subframe of a designated one of the transmission bursts transmitted in direction j 'corresponding to the transmission direction i', and the transmitting node has obtained ACK/NACK for this subframe. The designated transmission burst refers to a transmission burst closest to the current subframe and including a signal in the transmission direction j'. The relation between the direction j 'and the direction i' is that the direction j '=the direction i', i.e. the beam transmission direction of the reference subframe corresponds to the transmission direction of the burst to be transmitted currently, is a single beam direction, or the direction j 'includes the direction i', i.e. the beam transmission direction of the reference subframe may be plural, and the plural beam directions form a beam group corresponding to the transmission direction of the burst to be transmitted currently. That is, direction j 'is the single or multiple beam directions corresponding to direction i'.

Preferably, the direction j 'includes the direction i', and the beam group division in step 101 may be performed, for example, all directions of the beam group where the direction i 'is located are directions j'. For example, 16 directions, into 4 groups. The 1 st to 4 th beams are the first group, the 5 th to 8 th beams are the second group, and so on. Assuming that the direction i 'is the 5 th beam, the direction j' includes the directions of the 5 th to 8 th beams. Namely, the subframe k is a reference subframe as long as the subframe k contains a transmission signal in at least any one direction of the 5 th to 8 th beams. For another example, assuming that each beam group is 3 beams, the direction j 'includes three directions of direction i' -1, direction i 'and direction i' +1.

Preferably, when the direction of the subframe that the transmitting node currently wants to transmit is a plurality of directions, the reference subframe k is a subframe containing at least a transmission signal of one direction.

For example, as shown in fig. 6, the eNB uses beam direction 2 in the N-1 th downlink transmission burst, beam direction 1 in the N-th downlink transmission burst, and beam direction 2 in the n+1 th downlink transmission burst. Then the reference subframe of the CWS employed by the LBT performed before the n+1th downlink transmission burst is not the first subframe of the N-th downlink transmission burst, but the first subframe of the N-1 th downlink transmission burst.

For another example, as shown in fig. 7, it is assumed that the downlink burst N-1 is transmitted in the beam direction 2, the downlink burst N is transmitted in the beam direction 1, and the downlink burst n+1 is transmitted in the beam direction 2 and the beam direction 3. Then the first subframe of the downlink burst N-1 is the reference subframe of the beam direction 2 and the beam direction 3 of the downlink burst n+1 (LBT before the downlink burst n+1 may be omni-directional LBT, so that the beam direction 2 and the direction 3 adopt the same LBT or LBT before the downlink burst n+1 is directional LBT, the reference subframe of the LBT in the beam direction 2 and the direction 3 are the same subframe, or the first subframe of the downlink burst N-1 is only the reference subframe of the beam direction 2 of the downlink burst n+1 (LBT before the downlink burst n+1 is directional LBT, LBT in the beam direction 2 and the direction 3 are respectively directional LBT, then the reference subframe of the LBT in the beam direction 2 is the first subframe of the downlink burst N-1, and the reference subframe of the LBT in the beam direction 3 is the first subframe of the burst found further including the beam direction 3).

As another example, as shown in fig. 8, the eNB adopts beam direction 2 in the first 4 subframes in the nth downlink transmission burst, adopts beam direction 1 in the second 2 subframes in the nth downlink transmission burst, and adopts beam direction 1 in the n+1th downlink transmission burst. Then the reference subframe of the CWS used by the LBT performed before the n+1th downlink transmission burst is not the first subframe of the nth downlink transmission burst, but the 5 th subframe of the nth downlink transmission burst, i.e., the 1 st subframe of beam direction 1.

Step 202: and the sending node adjusts the length of a contention window for carrier monitoring of the current subframe according to the ACK/NACK statistical result of the reference subframe, and monitors the carrier.

And counting the ACK/NACK result of the reference subframe determined in the step 201, and adjusting the carrier monitoring CWS size of the guard period subframe according to the counted result.

Preferably, when counting the ACK/NACK in the reference subframe for adjusting the CWS, only the ACK/NACK of the transmission in the direction j 'corresponding to the transmission direction i' in the reference subframe is counted, and the ACK/NACK in the other directions is not counted. The direction j here includes the case of the single beam described above, as well as the case of the beam group described above. For example, if the principle of single beam correspondence is adopted, the eNB has downlink transmission in direction i and downlink transmission in direction i in the reference subframe, and only the ACK/NACK result of the downlink transmission in direction i is counted. For another example, if the principle of beam group correspondence is adopted, the eNB has downlink transmission in direction i and downlink transmission in direction i in the same beam group in the reference subframe, then both the direction i' and ACK/NACK result of downlink transmission in direction i are counted, or the eNB has only downlink transmission in direction i in the reference subframe, and the direction i are in the same beam group, then ACK/NACK result of downlink transmission in direction i is counted.

For another example, the eNB may support beams in 16 directions. In the nth downlink transmission burst, beam direction 2 and beam direction 8 are adopted to transmit signals for UE1 and UE2, respectively, wherein beam direction 8 and beam direction 2 are not in one beam group. The eNB uses beam direction 2 to transmit signals for UE3 in the n+1th downlink transmission burst. Then the reference subframe of the CWS employed by the LBT performed before the n+1th downlink transmission burst is the first subframe of the N-th downlink transmission burst and the counted ACK/NACK includes only the ACK/NACK of UE 1. When the total number of NACKs exceeds 80%, the CWS is increased to the next CWS value, otherwise the CWS value is reset.

For another example, the eNB uses beam direction 2 and beam direction 3 in the nth downlink transmission burst to transmit signals for UE2 and UE3, respectively, where beam direction 2 and direction 3 are the same beam group, i.e., beam direction 3 is the reference beam of beam direction 2. The eNB adopts beam direction 2 in the n+1th downlink transmission burst. Then the reference subframe of the CWS employed by the LBT performed before the n+1th downlink transmission burst is the first subframe of the N-th downlink transmission burst and the statistical ACK/NACK includes both the ACK/NACKs of UE2 and UE 3. When the total number of NACKs exceeds 80%, the CWS is increased to the next CWS value, otherwise the CWS value is reset.

As described above, the method in this embodiment determines the reference subframe according to the transmission direction, and in consideration of the flexibility of configuration, the determination manner of the reference subframe may be configured by a higher layer. If the higher layer configuration determines the reference subframe and the statistic ACK/NACK according to the transmission direction, the carrier monitoring is performed in the manner of steps 201 and 202, otherwise, the reference subframe and the statistic ACK/NACK may be determined, for example, according to the method of the existing LAA system.

Preferably, the specific manner of CWS adjustment according to the statistical ACK/NACK result in the present application may be the manner in the existing LAA system, see in particular TS 36.213 15.1.3, and 15.2.2.

Preferably, the reference subframe of the present embodiment is defined on the transmission direction, and the LBT is not limited on whether it is directional or omni-directional, and may be applied.

Example 3:

in the existing LAA system, after the base station occupies the channel through Cat-4LBT, when the time length of the downlink subframes continuously transmitted by the base station and the uplink subframes scheduled by the base station does not exceed the maximum occupation time (MCOT), the uplink subframes can use 25us LBT to realize signal transmission as soon as possible. This approach is simply referred to as up-down sharing MCOT. In the prior art, the base station may indicate 25us LBT in two ways. One is through LBT type indication information in UL grant. Another is to indicate which subframes are within the MCOT and which are not. If the user performs LBT in subframes within the MCOT, 25us LBT may be used, otherwise Cat-4LBT is used. If the UE previously received the LBT type indicated in the UL grant as Cat-4, but then received the C-PDCCH again, and found that the subframe to be LBT is within the MCOT, the UE performs 25us LBT. In the C-PDCCH, it may also indicate that no subframe belongs to MCOT, and then the UE considers that LBT may be performed according to the LBT type indicated by UL grant. In the existing LAA system, the LBT is omni-directional, and the downlink transmission has a certain directivity based on the precoding, but still includes signals transmitted omni-directionally. It can be said that the base station can help the UE to occupy the channel to some extent once Cat-4LBT successfully starts transmitting signals. The UE can rapidly occupy the channel through faster LBT and continue to transmit in the MCOT.

Whereas in the unlicensed band of the high band, LBT may be directional and the transmitted signal may be directional as previously described. If the base station occupies the channel by Cat-4LBT in the direction m, and the uplink transmission direction n of the UE scheduled in the MCOT is two directions completely different from the direction m, if the UE can still occupy the channel rapidly by using 25us LBT, interference may be caused to other nodes or the channel may be occupied more aggressively than other nodes. Therefore, the carrier monitoring method of the present embodiment proposes that the UE can share the MCOT with the base station when the base station is required to correspond to the transmission direction of the UE.

In this embodiment, the method for carrier monitoring on the unlicensed band includes:

step 301: the first transmitting node determines an LBT type indication sent to the second transmitting node according to the direction of a sending signal and/or the direction of carrier monitoring (LBT) and the direction of the sending signal of the scheduled second transmitting node, and the LBT type indication is used for indicating the second transmitting node to monitor the carrier.

Preferably, the transmitting node in this embodiment may be a base station, or may be an end user. A more common case, in which the first transmitting node is a base station and the second transmitting node is a UE, will be described below as an example.

Preferably, the base station may determine, according to the direction of the downlink signal sent and the direction of the signal sent by the uplink of the scheduled UE, an LBT type indication sent to the second sending node, and use the LBT type indication information to indicate to the UE how to perform carrier monitoring.

For example, if the transmission direction m of the downlink signal corresponds to the signal direction n of the uplink transmission of the UE, and the uplink transmission of the scheduled UE is still within the MCOT, the base station may instruct the UE to perform 25us LBT, otherwise perform Cat-4LBT. The correspondence of the direction m and the direction n may be referred to as the correspondence of i and j in embodiment 1 or the correspondence of j 'and i' in embodiment 2 of the present invention.

Alternatively, preferably, the base station may determine the LBT type indication sent to the second sending node according to the direction of carrier monitoring performed before sending the downlink signal and the signal direction of uplink transmission of the scheduled UE.

For example, if an omni-directional LBT is performed before transmitting the downlink signal, the base station may instruct the UE to perform a 25us LBT if the uplink transmission of the scheduled UE is still within the MCOT, otherwise perform a Cat-4LBT.

Preferably, if the base station is to transmit an indication of 25us LBT, the base station needs to complete the downlink Cat-4LBT in the carrier monitoring direction corresponding to the transmission direction of all UEs that will use 25us LBT before transmitting the downlink. If the base station chooses Cat-4LBT that is only downlink in a partial direction, the base station cannot instruct the UEs in the other direction to do 25us LBT, or the base station cannot instruct any one of the UEs transmitting in this MCOT to do 25us LBT.

For another example, if the direction m' of directional carrier monitoring performed before transmitting the downlink signal corresponds to the uplink transmission direction n of the scheduled UE, and the uplink transmission of the scheduled UE is still within the MCOT, the base station determines that the LBT type indication is an indication of 25us LBT, and otherwise determines that the LBT type indication is an indication of Cat-4LBT. If the direction m' of directional carrier monitoring performed before the downlink signal is sent does not meet the corresponding relation with the uplink sending direction n of the scheduled UE, the base station instructs the UE to perform Cat-4LBT no matter whether the uplink sending of the scheduled UE is in MCOT or not.

In addition, preferably, the LBT type indication information sent by the base station may be carried by uplink scheduling information UL grant of the scheduling UE, or may be carried by downlink cell common signaling, such as C-PDCCH.

Preferably, when the LBT type indication is carried through the cell common signaling, the cell common signaling may further include direction information of signal transmission or carrier monitoring by the base station. This direction information will be used in step 302 for the UE to compare the received direction information with the direction of the UE uplink transmission to determine if the indicated LBT type is applicable.

Preferably, the direction information in the cell common signaling may be indicated explicitly in the cell common signaling, or may be indicated implicitly by the resources used for the cell common information, such as using a different sequence when CRC scrambling, or by different frequency domain resources.

Step 302: the second sending node receives the indication information of the LBT type from the first sending node, determines the LBT type of the second sending node according to the indication information, and monitors the carrier according to the LBT type.

Preferably, the UE determines the LBT type according to the received LBT type indication information. Specifically, if the UE receives LBT type indication information through the UL-grant, the LBT type is determined according to the UL-grant indication. And if the UE receives the indication information of the LBT type through the C-PDCCH, determining the LBT type according to the information received by the C-PDCCH. In addition, in general, the C-PDCCH is sent in a directional manner, if the UE can receive the indication information of the LBT type through the C-PDCCH, which indicates that the uplink signal sending direction and the carrier monitoring direction correspond to the downlink signal sending direction, if the direction information carried in the C-PDCCH corresponds to the uplink signal sending direction, it may not need to determine whether the uplink transmission subframe is within the MCOT indicated by the C-PDCCH, if yes, 25us LBT may be performed, otherwise, cat-4LBT may be determined or the LBT type may be determined according to a predefined LBT type.

Or, preferably, if the LBT type indication information is received through the cell common signaling (e.g. C-PDCCH) to indicate that 25us LBT is performed, the UE may further determine whether the direction m or m' indicated by the direction information carried by the cell common signaling (e.g. C-PDCCH) corresponds to the direction n of uplink transmission of the UE. If the uplink transmission subframe is within the MCOT indicated by the C-PDCCH, 25us LBT is carried out, otherwise, cat-4LBT is determined to be carried out or the LBT type is determined according to the predefined LBT type.

In addition, as previously described, it is possible in the prior art to indicate on the C-PDCCH which subframes are within the MCOT and which are not, thereby determining whether to perform 25us LBT. This embodiment can also be indicated in this way. And after the UE receives the C-PDCCH, judging whether the uplink transmission subframe is within the MCOT indicated by the C-PDCCH, if so, performing 25us LBT, and if not, determining the LBT type according to the UL-grant indication or the predefined LBT type. Or before 25us LBT is performed, it may further be determined whether the uplink transmission direction corresponds to the direction information carried by the C-PDCCH, and 25us LBT is performed when the uplink transmission direction corresponds to the direction information carried by the C-PDCCH, and if the uplink transmission direction does not correspond to the direction information carried by the C-PDCCH, the LBT type is determined according to the UL-grant indication or the predefined LBT type.

Preferably, the correspondence between the direction m or m ' indicated by the direction information carried by the C-PDCCH and the direction n of the UE uplink transmission may be the same as the relationship between i and j in embodiment 1 or the relationship between j ' and i ' in embodiment 2 of the present invention.

For example, as shown in fig. 9, the base station schedules downlink data traffic of UE1 and UE3, and schedules uplink data traffic of UE1 and UE 2. The base station performs LBT in beam direction 1, after success, transmits downlink data traffic for UE1 with beam direction 1, transmits 2 consecutive subframes (subframe n and subframe n+1), and transmits downlink data traffic (subframe n+2) for UE3 in beam direction 1. And scheduling UE1 to transmit uplink traffic in subframes n+4 and n+5, and scheduling UE2 to transmit uplink traffic in subframe n+6. It is assumed that the uplink scheduling is cross-carrier scheduling, for example, UL grant is sent on a licensed band carrier. Let MCOT be 6 in length. Both UE1 and UE2 receive C-PDCCH signaling containing MCOT information in subframe n+2, indicating that MCOT will end at the end of subframe n+6. Assuming that the C-PDCCH includes a direction information indication, indicating that the beam direction is 1, UE1 performs 25us LBT according to LBT in the MCOT, but UE2 falls in the MCOT in time, because the beam direction does not correspond, UE2 can only perform according to LBT outside the MCOT, i.e., cat-4LBT.

In fig. 9 described above, it is generally considered that if the transmission of the C-PDCCH is also based on the beam direction 1, then the UE2 may not be able to receive the C-PDCCH information. But the direction information is also carried on the C-PDCCH, which takes into account the following problems that may occur: in order to avoid that UE2 can still demodulate the C-PDCCH correctly at a lower signal-to-noise ratio, if the C-PDCCH does not contain direction information, UE2 can perform LBT according to the method of sharing MCOT according to demodulating the C-PDCCH, which may cause UE2 to use 25us LBT, but in reality the base station does not perform downlink Cat-4LBT in beam direction 2, thereby causing UE2 to occupy the uplink channel too aggressive. To avoid the above possible problems, the direction information is preferably carried on the cell common signaling (e.g. C-PDCCH) in this embodiment.

After the carrier monitoring, the second transmitting node performs signal transmission in the corresponding direction for the transmitting direction corresponding to the direction through the carrier monitoring. The correspondence between the carrier monitoring direction and the transmission direction may be the same as the correspondence between the direction i and the direction j in embodiment 1 or the correspondence between the direction j 'and the direction i' in embodiment 2.

Example 4:

in the existing LTE system, a carrier operating in a licensed band periodically transmits a discovery signal (DRS) within a DMTC window, and the location of the DRS within the DMTC window is fixed. In LAA systems, the DRS is not fixed in position within the DMTC window, but may be within any one of the subframes within the DMTC window.

If joint beamforming is employed on unlicensed bands, the DRS may need to be transmitted in different beam directions so that UEs in each direction within the cell have an opportunity to detect the DRS.

Preferably, the DRS may be similar to the existing DRS, and at least include PSS/SSS and RSs for performing RRM measurement, and may also include RSs related to beam measurement, such as BRS. For convenience of description, these signals are collectively referred to as DRS. But the present embodiment is equally applicable to other periodically transmitted RSs for measurement.

In this embodiment, the method for transmitting the DRS on the unlicensed band includes:

step 401: either omni-directional or directional carrier monitoring is performed.

Step 402: and transmitting the DRS in a transmission direction corresponding to the direction monitored by the carrier.

Preferably, when the base station transmits the DRS, the base station may still transmit the DRS in all directions in the DMTC window, where the position of the DRS in all directions in the DMTC window may be fixed, or the sequence of the DRSs in all directions in the DMTC window may be fixed, but the position may not be fixed, or the sequence and the position of the DRSs in all directions in the DMTC window may not be fixed.

For the case where the positions of the DRSs of each direction within the DMTC window are fixed, the positions of the DRSs of each direction within the DMTC window may be predefined or configured by a higher layer.

Preferably, when the positions of DRSs in respective directions within the DMTC window are fixed, if the base station performs omni-directional LBT, the base station may start performing LBT from before the first DRS transmission position, skip the DRS transmission in the respective directions if LBT is not completed before a certain DRS transmission position, and start transmitting DRSs in the respective directions from the latest one DRS transmission position where LBT is completed, and continuously transmit the remaining DRSs. As shown in fig. 10.

Preferably, when the positions of DRSs in respective directions within the DMTC window are fixed, if the base station performs directional LBT, the base station may perform LBT before each fixed DRS transmission position. If the LBT of the DRS in a certain direction does not pass, the DRS in the certain direction is not transmitted, and if the LBT of the DRS in the certain direction passes, the DRS in the corresponding direction is transmitted. As shown in fig. 11.

For the case that the order of DRSs in each direction within the DMTC window is fixed but the location is not fixed, the order of DRSs in each direction within the DMTC window is fixed, but the starting location of DRSs within the DMTC window is not fixed, and may be any one of a plurality of starting locations within the DMTC window where DRSs may be transmitted.

Preferably, when the transmission order of the DRSs is fixed but the starting position is not fixed within the DMTC window, if the base station performs an omni-directional LBT, the base station may start performing an LBT before the possible starting point of the first DRS, if the LBT is not completed, may perform an LBT before the possible starting point of the next DRS, and so on until the LBT is passed, and the DRSs of the first direction are transmitted starting from the starting position where the DRS may occur most recently through the LBT, and the DRSs of all directions are continuously transmitted.

Wherein the possible starting point positions of the first DRS are predefined, or configured. Preferably, the length of one DRS may be used as a unit, or the total length of all DRSs may be used as a unit. For example, the total length of all DRSs is approximately 1 subframe long, then the possible starting point of the first DRS is the starting point of each subframe, as shown in fig. 12. For example, if each DRS has a length Lx, then the possible starting point of the first DRS is an integer multiple of Lx in the DMTC window, or an offset of LBT length is added, as shown in fig. 13.

Preferably, when the transmission order of the DRSs is fixed but the starting point position is not fixed within the DMTC window, if the base station performs directional LBT, the base station sequentially performs LBT for each direction according to the transmission order of the DRSs for each direction. Wherein for LBT of each direction, LBT may be started before the possible start point of DRS of each direction, if LBT fails, LBT may be performed before the next possible start point of DRS of the corresponding direction in turn, and so on until LBT is passed. In the above manner, although the location of each DRS may be not fixed, each DRS follows a predefined direction order, if the DRS with the front direction has not been successfully transmitted, LBT with the rear direction will not be performed, and DRSs with the rear direction will not be transmitted, as shown in fig. 14.

Preferably, when the starting point position of the DRS is not fixed within the DMTC window, if the base station performs directional LBT, the base station may start performing LBT before each possible starting point of the DRS, and if LBT is not completed, may perform LBT before the possible starting point of the next DRS. And the location of each DRS may be not fixed, or the order may be not fixed. As shown in fig. 15.

Preferably, when the location and the sequence of the DRSs are not fixed, the transmitted DRSs need to be able to identify the direction. Preferably, if the sequence of DRSs in each direction is the same and control signaling is also sent when the DRSs are sent, the control signaling contains information that can indicate the direction directly or indirectly. Alternatively, preferably, the sequence of the DRSs in each direction is different, e.g. using a different base sequence, or using a different scrambling code, or using a different cyclic shift, or carrying different direction information via the DRS signal.

In this way, the UE can determine the corresponding direction after receiving the DRS at an indeterminate location. If the location of each DRS is fixed, the UE can determine the corresponding direction by receiving the time location of the DRS without additional indication. But if the location of each DRS is fixed, the probability of transmitting the DRS is reduced.

Preferably, if the channel-occupied signal can be transmitted before the DRS is transmitted, the channel-occupied signal length cannot exceed the predefined length Lx.

Preferably, if the base station has the capability to perform LBT in multiple directions at the same time, DRSs may be transmitted in multiple directions passing through LBT at the same time.

Preferably, the base station may configure the number of DRSs transmitting directivity. For example, the base station may configure only transmission of DRSs in a partial direction.

Preferably, the base station may configure the period independently for DRSs in each direction.

As can be seen from the above-described processing of the present embodiment, the present embodiment is a specific example of embodiment 1, where the signal sent in embodiment 1 is DRS, that is, the present embodiment. Therefore, in this embodiment, there is the same correspondence between the monitoring direction and the sending direction of the DRS as in embodiment 1, that is, the correspondence between the direction i and the direction j in embodiment 1, and the correspondence is not described in detail in this embodiment.

Example 5:

on carriers in the high frequency band, beamforming is typically required to compensate for the path loss. Thus, it is necessary to transmit a signal for beam measurement, such as beam reference signal Beam Refernece Signal (BRS), or beam accurate reference signal Beam Refinement Reference Signal (BRRS). These signals often need to be transmitted in multiple directions in a beam sweep (beam sweep) manner.

If the BRS/BRRS is configured to be periodically transmitted, it is not necessarily possible to transmit on the unlicensed band according to periodicity, because the LBT cannot ensure that the BRS/BRRS can be transmitted at the corresponding point in time.

Preferably, if the transmitting node transmits only BRS/BRRS and does not transmit other data, the transmitting node may use faster LBT than the transmitting data. If transmitted with data, the type of LBT used to transmit the data should be the same.

Preferably, the method comprises the steps of,

(1) The transmitting node performs an omni-directional LBT before transmitting the BRS/BRRS, and if the LBT succeeds before the nth beam of the beam sweep (total M beams), the transmitting node may continuously transmit from the nth beam until the mth beam.

(2) When the transmitting node performs an omni-directional LBT before transmitting the BRS/BRRS, for the BRS/BRRS in a direction not immediately transmitted after completing the LBT, it is necessary to perform an omni-directional or corresponding directional fast LBT, such as the second type or third type LBT in embodiment 1, again before transmitting. For example, there are 14 BRSs in total, and the positions of the BRSs in the 14 directions are sequentially arranged in time so as to correspond to the 1 st to 14 th symbols, respectively. Assuming that the eNB completes the omni-directional LBT before the 5 th symbol, the BRS of direction 5 may be transmitted beginning at the 5 th symbol. And the fast LBT is performed before the 6 th to 14 th symbols start to be transmitted, respectively.

(3) When the transmission node performs directional LBT before transmitting the BRS/BRRS, it is necessary to perform LBT in a corresponding direction before transmitting the BRS/BRRS in each direction.

The transmission of the beam measurement signal of the present embodiment can be regarded as an example in which the signal transmitted in embodiment 1 is a beam measurement signal.

The method for carrying out carrier monitoring and signal transmission on the unlicensed frequency band is specifically realized. The application also provides equipment for carrying out carrier monitoring and signal generation on the unlicensed frequency band, and the equipment can be used for implementing the method.

Specifically, the basic structure of the signal transmission apparatus provided in the present application is shown in fig. 16, corresponding to embodiment 1. In fig. 16, the signal transmission apparatus includes: carrier monitoring unit and signal transmitting unit.

The carrier monitoring unit is used for monitoring the first type of carrier in the direction i and notifying the signal transmitting unit after the first type of carrier is monitored. A signal transmitting unit for starting signal transmission in a transmitting direction j after receiving the notification of the carrier monitoring unit; where direction i is omni-directional or a single or multiple beam direction corresponding to direction j.

Corresponding to embodiment 2, the basic structure of the carrier monitoring device provided in the present application is as shown in fig. 17, and in fig. 17, the carrier monitoring device includes: and the reference subframe determining unit and the carrier monitoring unit.

The reference subframe determining unit is used for determining a reference subframe for monitoring the current subframe carrier according to the sending direction of the current subframe. And the carrier monitoring unit is used for adjusting the length of a contention window for carrier monitoring of the current subframe according to the ACK/NACK statistical result of the reference subframe and carrying out carrier monitoring of the current subframe.

Corresponding to embodiment 3, the basic structure of the first transmitting node device provided in the present application is shown in fig. 18. In fig. 18, the first transmitting node apparatus includes: an LBT type indication determining unit and an LBT type indication transmitting unit.

The LBT type indication determining unit is used for determining the LBT type indication sent to the second sending node according to the direction of the signal sent by the first sending node and/or the direction of carrier monitoring and the direction of the signal sent by the scheduled second sending node. And the LBT type indication sending unit is used for sending the LBT type indication and used for the second sending node to monitor the carrier wave on the unlicensed frequency band.

Corresponding to embodiment 3, the basic structure of the second transmitting node device provided in the present application is shown in fig. 19. In fig. 19, the second transmitting node apparatus includes: a receiving unit, a carrier monitoring unit and a transmitting unit.

The receiving unit is configured to receive an LBT type indication sent by the first sending node. And the carrier monitoring unit is used for carrying out carrier monitoring on the unlicensed frequency band according to the LBT type indication. And the transmitting unit is used for transmitting signals in the transmitting direction corresponding to the direction monitored by the carrier.

Corresponding to embodiment 4, the basic structure of the signal transmission device provided in the present application is shown in fig. 20. In fig. 20, the signal transmission apparatus includes: carrier monitoring unit and DRS transmitting unit.

The carrier monitoring unit is used for carrying out omnidirectional or directional carrier monitoring. And the DRS sending unit is used for sending the DRS in the direction monitored by the carrier.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather to enable any modification, equivalent replacement, improvement or the like to be made within the spirit and principles of the invention.

Claims

1. A method performed by a transmitting node in a wireless communication system over an unlicensed frequency band, the method comprising:

Performing listen-before-send (LBT) on the first beam direction; wherein the first beam direction is a single beam direction covering all transmit beam directions, or the first beam direction comprises a plurality of beam directions, each of the plurality of beam directions covering one transmit beam direction;

if the LBT result is passing, signal transmission is carried out in the direction of the transmitting wave beam;

wherein when signals of a plurality of beams need to be transmitted in one transmission burst, performing LBT on the first beam direction includes:

for each of a plurality of transmit beam directions, performing LBT in a corresponding beam direction included in the first beam direction; alternatively, LBT is performed in a first beam direction covering all transmit beam directions;

the method comprises the following steps: for the beam directions of the signals which are not directly transmitted after passing through the LBT, before transmitting the signals of the corresponding beam directions, performing a second type of LBT on the corresponding beam directions, and after the second type of LBT passes through, performing signal transmission on the corresponding beam directions; or, for the beam direction in which the signal is not directly transmitted after passing through the LBT, if the signal starts to be transmitted within the first set time after passing through the LBT, before the signal starts to be transmitted, performing a second type LBT on the corresponding beam direction, and after passing through the second type LBT, starting signal transmission in the corresponding beam direction;

Wherein the time of the second type of LBT is shorter than the time of LBT performed for the first beam direction.

2. The method as recited in claim 1, further comprising:

determining a transmitting beam direction according to the first beam direction; or,

a first beam direction is determined based on the transmit beam direction.

3. The method of claim 1, wherein LBT is performed in a corresponding beam direction included in the first beam direction simultaneously, the method further comprising:

in the multiple corresponding beam directions, for the beam direction k passing through the LBT in time, in the set time before the LBT is completed in other beam directions, performing a third type of LBT in the beam direction k, and after passing through the third type of LBT in the beam direction k, starting signal transmission in the beam direction corresponding to the beam direction k; wherein the time of the third type of LBT is shorter than the time of LBT performed for the first beam direction;

or,

for a plurality of corresponding beam directions of LBT, adopting the same competition window CWS;

or,

for a plurality of corresponding beam directions of LBT, adopting the same random back-off factor;

or,

For a plurality of corresponding beam directions in which LBT is performed simultaneously, respective random back-off factors are generated in different beam directions, respectively.

4. The method of claim 1, wherein the transmitting node is a base station, and wherein starting signal transmission in the transmit beam direction comprises: and starting to transmit a discovery signal DRS in the transmission beam direction.

5. The method of claim 4 wherein the base station transmits DRSs for each beam direction within a DMTC window when transmitting the DRSs; wherein the transmission position of each beam direction DRS within the DMTC window is fixed.

6. The method of claim 5, wherein the step of determining the position of the probe is performed,

when the LBT by the base station is an omni-directional LBT,

said performing LBT in the transmit beam direction comprises: the base station starts omni-directional LBT before the first DRS starting point in the DMTC window; the starting signal transmission in the transmission beam direction after LBT passes includes: in the DMTC window, when the DRS is not transmitted before passing through the LBT, the DRS in the corresponding direction is transmitted from the earliest DRS transmitting position after passing through the omni-directional LBT, and the remaining DRS in the DMTC window is continuously transmitted;

And/or the number of the groups of groups,

when the LBT performed by the base station is a directional LBT,

said performing LBT in the transmit beam direction comprises: and the base station performs LBT in the corresponding direction before each DRS transmitting position in the DMTC window, if the LBT is not passed, the DRS in the corresponding beam direction is not transmitted, and if the LBT is passed, the DRS in the corresponding beam direction is transmitted.

7. The method of claim 4 wherein the base station transmits DRSs in all directions within a DMTC window when transmitting the DRSs; wherein, the transmission sequence of the DRSs in each direction in the DMTC window is fixed, and the starting point position is not fixed.

8. The method of claim 7, wherein the step of determining the position of the probe is performed,

when the LBT performed by the base station is an omni-directional LBT, the performing the LBT in the transmission beam direction includes: the base station performs LBT before the possible starting point of the first DRS in the DMTC window, and when the LBT is not passed, sequentially performs LBT before the possible starting point of the next DRS until the LBT is passed; the starting signal transmission in the transmission beam direction based on the LBT result includes: within the DMTC window, after passing through the LBT, transmitting DRSs of a first beam direction from the earliest possible DRS after passing through the LBT, and continuously transmitting DRSs of all beam directions within the DMTC window;

And/or the number of the groups of groups,

when the LBT performed by the base station is directional LBT, the performing LBT in the transmission beam direction includes: in the DMTC window, sequentially carrying out LBT on each wave beam according to the sending sequence of DRS in each direction; wherein the base station performing LBT for each beam direction includes: performing LBT before the possible starting point of each beam direction DRS, and when the LBT is not passed, sequentially performing LBT before the next possible starting point of the direction DRS until the LBT is passed; the starting signal transmission in the transmission beam direction based on the LBT result includes: after passing LBT of one direction, the base station starts to transmit DRSs of corresponding beam directions from the earliest possible start point position of DRSs of corresponding directions after passing LBT.

9. The method of claim 4 wherein the base station transmits DRSs for each beam direction within a DMTC window when transmitting the DRSs; and when the transmission sequence and the starting point position of the DRS in each direction in the DMTC window are not fixed, carrying the direction information of the DRS when the DRS is transmitted.

10. The method of claim 4 wherein when the base station supports LBT in multiple beam directions simultaneously, the base station transmitting DRSs in the beam direction through LBT comprises: the base station simultaneously transmits DRSs in a plurality of beam directions through the LBT.

11. The method according to claim 6 or 8, wherein the base station pre-configures the number of directional DRSs; and/or the base station independently configures the transmission period for the DRS in different directions.

12. The method of claim 1, wherein the signals transmitted in the plurality of beam directions are beam measurement signals;

when the beam measurement signal is transmitted together with a data signal, the LBT is performed according to carrier monitoring used for transmitting data;

when only the beam measurement signal is transmitted, the LBT time is shorter than the carrier monitoring time used to transmit data.

13. A signal transmitting apparatus in a wireless communication system, the apparatus comprising:

a transceiver;

a carrier monitoring unit, connected to the transceiver, configured to perform the method of any of claims 1-12.