JP2019169958A - Method and device for transmitting reference signal in cell using unlicensed frequency band - Google Patents

Abstract

To provide a method and a device for transmitting a reference signal in a cell using an unlicensed frequency band.SOLUTION: A method includes: a step 101 of determining a candidate resource set used when a first reference signal is transmitted in a cell using an unlicensed frequency band, and containing a predetermined resource and at least soft candidate resource by the candidate resource; a step 102 of determining a first candidate resource used when the first reference signal is transmitted in the cell using the unlicensed frequency band, and in which a channel on the unlicensed frequency band corresponded to the first candidate resource is in an idle state, and the first candidate resource is the predetermined resource or the soft candidate resource in the candidate resource; and a step 103 of transmitting the first reference signal on the first candidate resource.SELECTED DRAWING: Figure 1

Description

  Embodiments of the present invention relate to the field of communications, and more particularly to a method and device for transmitting a reference signal in a cell using an unlicensed frequency band.

  When cell selection, reselection, or handover is performed, user equipment (UE) can synchronize and identify cells according to the reference signal transmitted by the base station, channel state information (CSI) As well as radio resource management (RRM) measurements. Cell synchronization includes initial coarse synchronization and fine synchronization tracking time-frequency. In particular, the UE completes the first coarse synchronization according to the primary synchronization signal (Primary Synchronization Signal, PSS) and the secondary synchronization signal (Secondary Synchronization Signal, SSS) periodically transmitted by the base station, and periodically by the base station. Fine synchronization that tracks time-frequency according to the transmitted Cell-specific Reference Signal (CRS) may be completed. CSI measurements include channel measurements and interference measurements. The UE may perform channel measurement and interference measurement according to CRS or Channel State Information Reference Signal (CSI-RS) transmitted by the base station. RRM measurement includes reference signal received power (RSRP) measurement, reference signal received quality (RSRQ) measurement, and received signal strength indicator (RSSI) measurement. Etc. The UE may complete the RRM measurement according to the CRS periodically transmitted by the base station.

However, in communication systems that use unlicensed spectrum, when communications are performed by using unlicensed spectrum, certain coexistence specifications, such as Listen-Before-Talk, LBT) needs to be met. In particular, before transmitting a signal on a channel corresponding to an unlicensed spectrum, the base station needs to perform a clear channel assessment (CCA) on the channel. If the detected received power exceeds a preset threshold, the channel is considered in use, in which case the base station cannot transmit a signal on the channel. The base station can only transmit a signal on the channel when it is detected that the channel is idle.
Therefore, due to LBT specification limitations, the characteristics of periodic transmission of reference signals such as PSS, SSS, CRS, and CSI-RS are affected. For example, on a transmission opportunity within a pre-set period, the base station may detect that the channel is in use and then cannot transmit a reference signal on one or more transmission opportunities . This affects the cell synchronization and CSI measurements performed by the UE, and also affects the UE's mobility performance. In this case, how to transmit the reference signal in a communication system using an unlicensed spectrum in order to meet the requirements of cell synchronization and CSI measurement is a problem to be solved quickly.

NEC, Impact of LBT regulation on LAA [online], 3GPP TSG-RAN WG1 # 79 R1-144866, 3GPP, November 21, 2014, p.1-2, http://www.3gpp.org/ftp/ tsg_ran / WG1_RL1 / TSGR1_79 / Docs / R1-144866.zip LG Electronics, LBT operation details and initial evaluation results, 3GPP TSG-RAN WG1 # 79 R1-144900, 3GPP, November 8, 2014, p.1-7, URL, http://www.3gpp.org/ftp /tsg_ran/WG1_RL1/TSGR1_79/Docs/R1-144900.zip InterDigital Communications, On L1 design for LTE LAA DL only mode, 3GPP TSG-RAN WG1 # 79 R1-145052, 3GPP, November 21, 2014, p.1-5, URL, http://www.3gpp.org /ftp/tsg_ran/WG1_RL1/TSGR1_79/Docs/R1-145052.zip

  Embodiments of the present invention can increase the success rate of transmitting a reference signal in a cell using an unlicensed frequency band, and a method for transmitting a reference signal in a cell using an unlicensed frequency band And provide devices.

According to a first aspect, an embodiment of the invention is a method for transmitting a reference signal in a cell using an unlicensed frequency band, comprising:
Determining a candidate resource set to be used when the first reference signal is transmitted in a cell using an unlicensed frequency band, the candidate resource set comprising a preconfigured resource and at least one Including flexible candidate resources, the pre-configured resources are within the time window and are needed to transmit the first reference signal according to the first period when the cell is in the active state The flexible candidate resource is in the time window, the candidate resource is acquired after the preset resource is temporally translated, and the period in which the time window appears is the second A step in which the second period is longer than the first period; and
Determining a first candidate resource to be used when the first reference signal is transmitted in a cell using an unlicensed frequency band, the unlicensed frequency corresponding to the first candidate resource The channel on the band is in an idle state, and the first candidate resource is a preset resource or a flexible candidate resource in a candidate resource set; and
Transmitting a first reference signal on a first candidate resource.

In relation to the first aspect, in the first implementation method of the first aspect, the first reference signal is used when transmitted in a cell that uses an unlicensed frequency band. Determining a candidate resource, wherein a channel on an unlicensed frequency band corresponding to the first candidate resource is in an idle state,
Initiating a CCA for an unlicensed frequency band in a pre-set time interval before the first candidate resource to obtain a free channel assessment CCA result;
Determining that the channel on the unlicensed frequency band corresponding to the first candidate resource is in an idle state according to the CCA result.

In relation to the above-described implementation methods of the first aspect and the first aspect, in the second implementation method of the first aspect, an unlicensed frequency band corresponding to the first candidate resource is determined according to the CCA result. Determining that the upper channel is idle
Determining that the channel on the unlicensed frequency band corresponding to the first candidate resource is idle when the CCA result indicates that the channel is idle, or
Random backoff is performed when the CCA results indicate that the channel is idle, and when the channel is still idle within the random backoff time period, the unlicensed corresponding to the first candidate resource Determining that a channel on the frequency band is in an idle state.

In connection with the above implementation method of the first aspect and the first aspect, in the third implementation method of the first aspect, the step of transmitting the first reference signal on the first candidate resource comprises:
If it is determined that the moment when the channel is idle is the same as the start moment of the first candidate resource, transmitting the first reference signal on the first candidate resource, or if the channel is idle If it is determined that an instant is before the start of the first candidate resource, it sends a signal to fill the space to occupy the channel until the start of the first candidate resource, and then Including starting to transmit a first reference signal on one candidate resource.

In connection with the above implementation method of the first aspect and the first aspect, in the fourth implementation method of the first aspect, the first reference signal is used for cell synchronization. And transmitting the first reference signal on the first candidate resource, the method comprises:
When the first candidate resource occupies the corresponding amount of the last symbol of the time slot, the method further includes transmitting the second reference signal at the beginning of the next time slot when the first candidate resource ends. ,
The second reference signal includes one or more of a cell specific reference signal CRS, a channel state information-reference signal CSI-RS, or a positioning reference signal PRS.

In connection with the above implementation method of the first aspect and the first aspect, in the fifth implementation method of the first aspect, the first reference signal is a reference signal used for cell synchronization. And transmitting the first reference signal on the first candidate resource, the method comprises:
When the first candidate resource does not occupy the corresponding amount of the last symbol in the time slot, when the first candidate resource ends, it sends a signal that fills the vacancy until the time slot ends and the beginning of the next time slot Further comprising transmitting a second reference signal to
The second reference signal includes one or more of a cell specific reference signal CRS, a channel state information-reference signal CSI-RS, or a positioning reference signal PRS.

  In relation to the above-described implementation methods of the first aspect and the first aspect, in the sixth implementation method of the first aspect, the flexible candidate resource is the forward resource in the forward direction or the preset resource is It is a resource obtained after being converted in the reverse direction.

  In relation to the above-described implementation method of the first aspect and the first aspect, in the seventh implementation method of the first aspect, the temporal conversion granularity is one or more time slots.

  In connection with the above implementation method of the first aspect and the first aspect, in the eighth implementation method of the first aspect, the flexible candidate resource is tailed with a corresponding amount of time slots within the time window. Occupy symbols.

  In connection with the above implementation method of the first aspect and the first aspect, in the ninth implementation method of the first aspect, the time window is a neighbor of the same frequency to transmit the first reference signal It is the same as the time window in which the flexible candidate resources used by other cells are placed.

According to a second aspect, an embodiment of the invention is a method for transmitting a reference signal in a cell using an unlicensed frequency band, comprising:
Determining a time window in which a candidate resource set to be used when a first reference signal is transmitted in a cell using an unlicensed frequency band, the candidate resource set being pre-configured Including a resource and at least one flexible candidate resource, the pre-configured resource is within a time window and is required to transmit a first reference signal according to a first period when the cell is in an active state The flexible candidate resource is within the time window, the candidate resource is acquired after the preset resource is temporally converted, and the period in which the time window appears is the second period A step in which the second period is longer than the first period; and
Detecting a first reference signal on an unlicensed frequency band within a time window.

In relation to the second aspect, in the first implementation method of the second aspect, the first reference signal includes a reference signal used for cell synchronization and is on an unlicensed frequency band. After detecting the first reference signal, the method
If the first reference signal is successfully detected, detecting a second reference signal on an unlicensed frequency band, wherein, in time, transmission resources occupied by the second reference signal are After the transmission resource occupied by the first reference signal, the second reference signal is one of the cell-specific reference signal CRS, the channel state information-reference signal CSI-RS, or the positioning reference signal PRS Or include multiple.

In connection with the above implementation method of the second aspect and the second aspect, in the second implementation method of the second aspect, the first reference signal is transmitted in a cell using an unlicensed frequency band. Before determining the time window in which the candidate resource set to be used is placed,
Receiving radio resource control RRC signaling sent by the base station, the RRC signaling further carrying a time window length and a time period to appear.

  In relation to the above-described implementation methods of the second aspect and the second aspect, in the third implementation method of the second aspect, the flexible candidate resource is the forward resource in time or the preset resource is It is a resource obtained after being converted in the reverse direction.

  In relation to the above-described implementation methods of the second aspect and the second aspect, in the fourth implementation method of the second aspect, the temporal conversion granularity is one or more time slots.

  In connection with the above implementation method of the second aspect and the second aspect, in the fifth implementation method of the second aspect, the flexible candidate resource is tailed by a corresponding amount of time slots within the time window. Occupy symbols.

  In connection with the above implementation method of the second aspect and the second aspect, in the sixth implementation method of the second aspect, the time window is a neighbor of the same frequency for transmitting the first reference signal. It is the same as the time window in which the flexible candidate resources used by other cells are placed.

According to a third aspect, embodiments of the present invention
A first decision unit configured to determine a candidate resource set to be used when a first reference signal is transmitted in a cell using an unlicensed frequency band, the candidate resource set comprising: Includes a pre-configured resource and at least one flexible candidate resource, and the pre-configured resource is within a time window and transmits a first reference signal according to a first period when the cell is in an active state Is a candidate resource acquired after a flexible candidate resource is within a time window, a preset resource is temporally converted, and a period in which the time window appears is A first determination unit that is a second period, wherein the second period is longer than the first period;
A second decision unit configured to determine a first candidate resource to be used when a first reference signal is transmitted in a cell using an unlicensed frequency band, the first decision signal comprising: A second decision where the channel on the unlicensed frequency band corresponding to the candidate resource is in an idle state and the first candidate resource is a preset resource or a flexible candidate resource in a candidate resource set Unit,
A base station is provided that includes a transmission unit configured to transmit a first reference signal on a first candidate resource.

In relation to the third aspect, in the first implementation method of the third aspect, the second determination unit includes:
In order to obtain a free channel assessment CCA result, start a CCA for the unlicensed frequency band in a preset time interval before the first candidate resource,
The CCA result is specifically configured to determine that the channel on the unlicensed frequency band corresponding to the first candidate resource is in an idle state.

In relation to the above-described implementation method of the third aspect and the third aspect, in the second implementation method of the third aspect, the second determination unit includes:
Determining that the channel on the unlicensed frequency band corresponding to the first candidate resource is idle when the CCA result indicates that the channel is idle, or
Random backoff is performed when the CCA results indicate that the channel is idle, and when the channel is still idle within the random backoff time period, the unlicensed corresponding to the first candidate resource It is specifically configured to determine that a channel on the frequency band is in an idle state.

In relation to the above-described implementation method of the third aspect and the third aspect, in the third implementation method of the third aspect, the transmission unit comprises:
If it is determined that the moment when the channel is idle is the same as the start of the first candidate resource, send the first reference signal on the first candidate resource, or the channel is idle If it is determined that the instant is before the start of the first candidate resource, send a signal to fill the vacancy to occupy the channel until the start of the first candidate resource, then the first Is configured to begin transmitting the first reference signal on the candidate resources.

In connection with the above implementation method of the third aspect and the third aspect, in the fourth implementation method of the third aspect, the first reference signal is used for cell synchronization. And when the first candidate resource occupies the corresponding amount of the last symbol in the time slot, the transmitting unit may transmit the second reference signal at the beginning of the next time slot when the first candidate resource ends. Is further configured to send to
The second reference signal includes one or more of a cell specific reference signal CRS, a channel state information-reference signal CSI-RS, or a positioning reference signal PRS.

In connection with the above implementation method of the third aspect and the third aspect, in the fifth implementation method of the third aspect, the first reference signal is a reference signal used for cell synchronization. Including a transmitting unit
When the first candidate resource does not occupy the corresponding amount of the last symbol in the time slot, when the first candidate resource ends, it sends a signal that fills the vacancy until the time slot ends and the beginning of the next time slot Further configured to transmit a second reference signal to
The second reference signal includes one or more of a cell specific reference signal CRS, a channel state information-reference signal CSI-RS, or a positioning reference signal PRS.

  In relation to the above-described implementation methods of the third aspect and the third aspect, in the sixth implementation method of the third aspect, the flexible candidate resource is a forward resource in time or a preset resource is It is a resource obtained after being converted in the reverse direction.

  In relation to the above-described implementation method of the third aspect and the third aspect, in the seventh implementation method of the third aspect, the temporal conversion granularity is one or more time slots.

  In connection with the above implementation method of the third aspect and the third aspect, in the eighth implementation method of the third aspect, the flexible candidate resource is tailed by a corresponding amount of time slots within the time window. Occupy symbols.

  In connection with the above implementation method of the third aspect and the third aspect, in the ninth implementation method of the third aspect, the time window is the same frequency neighborhood for transmitting the first reference signal. It is the same as the time window in which the flexible candidate resources used by other cells are placed.

According to a fourth aspect, an embodiment of the invention is
A decision unit configured to determine a time window in which a candidate resource set used when a first reference signal is transmitted in a cell using an unlicensed frequency band is placed, the candidate resource set Includes a pre-configured resource and at least one flexible candidate resource, and the pre-configured resource is within a time window and the first reference signal according to a first period when the cell is in an active state This is a resource required for transmission, a flexible candidate resource is in the time window, is a candidate resource acquired after a preset resource is temporally converted, and a period in which the time window appears A second period, wherein the second period is longer than the first period; and
A user equipment is provided that includes a detection unit configured to detect a first reference signal on an unlicensed frequency band within a time window.

In relation to the fourth aspect, in the first implementation method of the fourth aspect, the first reference signal includes a reference signal used for cell synchronization, and the detection unit comprises:
If the first reference signal is successfully detected, the transmission resources are further configured to detect the second reference signal on the unlicensed frequency band and are occupied by the second reference signal in time Is after the transmission resources occupied by the first reference signal, and the second reference signal is one of the cell-specific reference signal CRS, the channel state information-reference signal CSI-RS, or the positioning reference signal PRS. Contains one or more.

  In relation to the above implementation method of the fourth aspect and the fourth aspect, in the second implementation method of the fourth aspect, the base station receives the radio resource control RRC signaling transmitted by the base station The RRC signaling carries the length of the time window and the period of time it appears.

  In relation to the above-described implementation methods of the fourth aspect and the fourth aspect, in the third implementation method of the fourth aspect, the flexible candidate resource is the forward resource in the forward direction or It is a resource obtained after being converted in the reverse direction.

  In relation to the above-described implementation method of the fourth aspect and the fourth aspect, in the fourth implementation method of the fourth aspect, the temporal conversion granularity is one or more time slots.

  In connection with the above implementation method of the fourth aspect and the fourth aspect, in the fifth implementation method of the fourth aspect, the flexible candidate resource is tailed with a corresponding amount of time slots within the time window. Occupy symbols.

  In connection with the above implementation method of the fourth aspect and the fourth aspect, in the sixth implementation method of the fourth aspect, the time window is a neighbor of the same frequency to transmit the first reference signal It is the same as the time window in which the flexible candidate resources used by other cells are placed.

  Based on the above technical solution, in an embodiment of the present invention, a candidate resource set is determined to transmit the reference signal in order to increase the transmission opportunity of the reference signal. Therefore, according to the embodiment of the present invention, the success rate of the transmission of the reference signal can be increased without affecting the communication of the normal system.

  BRIEF DESCRIPTION OF THE DRAWINGS To describe the technical solutions in the embodiments of the present invention more clearly, the following briefly describes the accompanying drawings required for describing the embodiments of the present invention. Apparently, the accompanying drawings in the following description show only some embodiments of the present invention, and those skilled in the art can still derive other drawings from these accompanying drawings without creative efforts. Is possible.

3 is a schematic flow diagram of a method for transmitting a reference signal in a cell using an unlicensed frequency band according to an embodiment of the present invention; FIG. 6 is a schematic diagram of a candidate resource set according to an embodiment of the present invention. FIG. 4 is a schematic diagram of a time-frequency resource according to an embodiment of the present invention. 4 is a schematic flow diagram of a method for transmitting a reference signal in a cell using an unlicensed frequency band according to another embodiment of the present invention. FIG. 2 is a schematic block diagram of a base station according to an embodiment of the present invention. FIG. 3 is a schematic block diagram of a user equipment according to an embodiment of the present invention. FIG. 6 is a schematic block diagram of a base station according to another embodiment of the present invention. FIG. 6 is a schematic block diagram of a user equipment according to another embodiment of the present invention.

  The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are a part rather than all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

  It should be understood that in the embodiments of the present invention, user equipment (User Equipment, UE) may be referred to as a terminal, a mobile station (Mobile Station, MS), a mobile terminal (Mobile Terminal), and the like. User equipment may communicate with one or more core networks by using a radio access network (RAN). For example, the user equipment may be a mobile phone (also referred to as a “cellular” phone) or a computer with a mobile terminal. For example, the user equipment may alternatively be a portable, pocket-sized, handheld, built-in computer, or in-vehicle mobile device that communicates voice and / or data with a radio access network.

  In the embodiment of the present invention, the base station may be an LTE evolved NodeB (Evolutional Node B, ENB, or e-NodeB), and is not limited in the present invention. However, for ease of explanation, the following embodiments use the base station ENB and the user equipment UE as examples for explanation.

  In a practical scenario, in order to allow the user equipment in the local cell to successfully acquire time-frequency synchronization information, channel estimation information, etc., the base station transmits a reference signal according to a preset period. The corresponding user equipment in the local cell detects the reference signal within this preset period, and acquires time-frequency synchronization information, channel estimation information, etc. according to the detected reference signal. In the embodiment of the present invention, this preset period is referred to as a first period and is within the first period, and the resource used to transmit the reference signal is a preset resource. be called.

  When a base station transmits a signal in a cell in an unlicensed frequency band, considering the introduction of a contention mechanism, the base station occupies the channel of the cell in the unlicensed frequency band for each preset resource It is difficult to ensure that you are allowed to. Opportunities for the base station to transmit the reference signal in a cell in a frequency band that does not require a license are reduced. As a result, it is difficult for user equipment in the local cell or in neighboring cells to obtain necessary information such as time-frequency synchronization information and channel measurement information in time, thereby affecting communication quality.

  In order to increase the opportunity for a base station to transmit a reference signal in a cell in an unlicensed frequency band, embodiments of the present invention provide a method for transmitting a reference signal in a cell using an unlicensed frequency band. suggest. Based on trying to transmit the reference signal on a pre-configured resource according to the first period of the prior art, a flexible candidate resource acts as a candidate resource for transmitting the reference signal, so that a period of time appears It is further set within a time window that is the second period.

  FIG. 1 is a schematic flowchart of a method for transmitting a reference signal in a cell using an unlicensed frequency band according to an embodiment of the present invention. The method shown in FIG. 1 may be performed by a base station, and the method includes:

  101. Determine a candidate resource set to be used when the first reference signal is transmitted in a cell using an unlicensed frequency band, the candidate resource set comprising a preconfigured resource and at least one flexible Pre-configured resources, including candidate resources, are resources that are within the time window and are needed to transmit the first reference signal according to the first period when the cell is in the active state, and are flexible The candidate resource is within the time window and is a candidate resource obtained after a preset resource is temporally converted. The period in which the time window appears is the second period and the second period. Is longer than the first period.

  It should be understood that an active cell is a relative concept to a dormant cell. Active cells transmit reference signals more frequently to the UE, while dormant cells transmit reference signals less frequently. For example, an active cell transmits a PSS / SSS signal once every 5 ms, while a dormant cell transmits a PSS / SSS signal once every 40 ms or 80 ms.

  For example, a system that performs communication using an unlicensed frequency band includes an LTE system U-LTE deployed in an unlicensed frequency band, a wireless local area network (WLAN) system, and the like. For example, to increase service capacity, carrier aggregation is generally performed on the U-LTE serving cell and the primary serving cell that serve the UE, which is used as a secondary serving cell on the unlicensed spectrum. The primary serving cell is deployed on the licensed spectrum.

  When serving a UE, a secondary serving cell using an unlicensed frequency band generally needs to send some reference signals to the UE for cell identification, cell synchronization, channel measurement, interference measurement, etc. There is. However, during the process of transmitting a reference signal to the UE by occupying a preset resource according to a preset period, when the channel is occupied due to LBT specification limitations, May not be completed.

  According to the method of this embodiment of the present invention, determining a candidate resource set for transmitting a reference signal increases the transmission opportunity of the reference signal, which further increases the success rate of transmission of the reference signal. be able to. The candidate resource set includes a preset resource and at least one flexible candidate resource. The flexible candidate resource and the preconfigured resource use the same frequency, which means that the flexible candidate resource is a resource that is acquired after the preconfigured resource is temporally transformed . In addition, flexible candidate resources need to fall within a time window that appears periodically.

  In particular, the second period in which the time window appears is longer than the preset first period for transmitting the reference signal. For example, the first period can be 5 ms and the second period is 40 ms or 80 ms. It should be understood that these examples are intended only to help those skilled in the art to better understand this embodiment of the invention and are not intended to limit the scope of this embodiment of the invention. . The length of the time window may be determined with reference to a status such as channel busyness level, which is not limited in this embodiment of the invention.

  102. Determine a first candidate resource to be used when the first reference signal is transmitted in a cell using an unlicensed frequency band, and on the unlicensed frequency band corresponding to the first candidate resource The first channel is an idle state, and the first candidate resource is a preset resource or a flexible candidate resource in the candidate resource set.

  103. Transmit the first reference signal on the first candidate resource.

  For example, channel congestion / idle states of preset resources and flexible candidate resources may be determined in chronological order. This time there are a total of three resources available to transmit the reference signal, and the temporal order of these three resources is the first flexible candidate resource, the preset resource, and the first It is assumed that there are two flexible candidate resources.

  Therefore, it may be determined first whether the channel on the first flexible candidate resource is idle, and if the channel is idle, the reference signal is on the first flexible candidate resource. (In this case, the first flexible candidate resource is the first candidate resource). Conversely, if the channel on the first flexible candidate resource is congested, it must be further determined if the channel on the pre-configured resource is idle and the channel is idle In this case, the reference signal is transmitted on a preset resource. Conversely, if the channel on the pre-configured resource is congested, it needs to be further determined if the channel on the second flexible candidate resource is idle and the channel is idle The reference signal is transmitted on the second flexible candidate resource (in this case, the second flexible candidate resource is the first candidate resource). Conversely, if the channel on the second flexible candidate resource is congested, the first reference signal cannot be transmitted on the second flexible candidate resource, i.e., the current first reference signal. Transmission fails.

  Based on the above technical solution, in this embodiment of the present invention, a candidate resource set is determined for transmitting the reference signal in order to increase the transmission opportunity of the reference signal. Thus, according to this embodiment of the present invention, the success rate of the transmission of the reference signal can be increased without affecting the normal system communication.

  Further, when the reference signal is transmitted in a communication system using an unlicensed spectrum, the solution provided in this embodiment of the present invention meets the requirements for cell synchronization and CSI measurement, and the UE demodulation and Mobility performance can be further guaranteed.

  In addition, the mainstream deployment scenario of this embodiment of the present invention performs carrier aggregation on a primary serving cell on a spectrum that requires a license and a U-LTE secondary serving cell on a spectrum that does not require a license to use. It is to be. The LTE primary serving cell and the U-LTE secondary serving cell may be deployed at the same location or may be deployed at different locations, and an ideal backhaul path exists between the two serving cells.

  Alternatively, in the present invention, deployment does not have an ideal backhaul path between the two serving cells, for example, the backhaul delay is relatively large and then information is quickly transferred between the two serving cells. May be performed in scenarios that cannot be adjusted to Furthermore, U-LTE serving cells that can be accessed independently may also be deployed in this embodiment of the invention, i.e., in this case, carrier aggregation is performed for the U-LTE serving cell and the LTE serving cell. There is no need. The application scenario described above is intended only to help those skilled in the art to better understand this embodiment of the invention and is not intended to limit the scope of this embodiment of the invention.

  Optionally, in an embodiment, when the first candidate resource to be used when the first reference signal is transmitted in a cell that uses an unlicensed frequency band is determined, a free space for the unlicensed frequency band A channel assessment CCA is started at a preset time interval before the first candidate resource to obtain a CCA result. Then, it is determined from the CCA result that the channel on the unlicensed frequency band corresponding to the first candidate resource is in the idle state.

  Optionally, in an embodiment, when the CCA result indicates that the channel is idle, the channel on the unlicensed frequency band corresponding to the first candidate resource is determined to be idle, or the CCA When the result indicates that the channel is idle, a random backoff is performed, and when the channel is still idle within the random backoff time period, the unlicensed frequency band corresponding to the first candidate resource It is determined that the upper channel is idle.

  FIG. 2 is a schematic diagram of a candidate resource set according to an embodiment of the present invention. In particular, as shown in FIG. 2, the time window appears once every 40 ms. The time window includes a preset resource and at least one flexible candidate resource. The start of CCA may be in a preset time interval before the flexible candidate resource.

  The preset resource is a resource used for transmitting the first reference signal when the transmission period is 5 ms. That is, regardless of whether the cell is within the time window or outside the time window, the first reference signal is transmitted according to a preset period of 5 ms. In addition, according to the method of this embodiment of the present invention, flexible candidate resources are further provided to the cell to increase the transmission opportunity of the first reference signal.

  The last two symbols of the first time slot of the first subframe in the time window (i.e., the sixth symbol and the seventh symbol in the subframe, and one subframe contains 14 symbols) Is assumed) is a preset resource. A flexible candidate resource may be obtained after a time-domain transformation is performed on the above-described preset resource within the time window, and the transformation in this specification is forward or backward. It may be a conversion. FIG. 2 shows the last two symbols of the second subframe within the time window (ie, the thirteenth symbol and the fourteenth symbol within the subframe).

  When time domain transformations are performed on pre-configured resources to obtain flexible candidate resources, the particular time granularity of the transformation may be symbol level, time slot level, or subframe level There is. For example, the symbol level means that a copy of one transform appears every 4 symbols, the time slot level means that a copy of one transform appears every 7 symbols contained in one time slot, The subframe level means that a copy of one transformation appears every 14 symbols included in one subframe.

  It should be noted that these examples are only intended to help those skilled in the art to better understand this embodiment of the invention and are not intended to limit the scope of this embodiment of the invention. .

  Thus, when the CCA result indicates that the channel is idle, the first reference signal is transmitted directly on the first candidate resource, but no random backoff is performed, which is And the success rate of the reference signal transmission can be increased.

  Alternatively, random backoff is performed first when the CCA result indicates that the channel is idle. The first reference signal is transmitted on the first candidate resource only when the channel is still idle within the random backoff time period. This can protect the signal transmission of another communication device in the system and prevent mutual interference between the transmission of the reference signal of the cell and the signal transmission of another communication device.

  Optionally, the starting point for starting the above-described CCA may be the start of the first subframe within the time window, in which case the above-mentioned preset time interval is 5 symbols . Alternatively, the preset time interval described above is the current maximum backoff time, for example, in particular, the length of the CCA unit time multiplied by the maximum value in the range of backoff counter values. May be the contention window length in the backoff mechanism equal to It should be noted that these examples are only intended to help those skilled in the art to better understand this embodiment of the invention and are not intended to limit the scope of this embodiment of the invention. .

  Optionally, in another embodiment, if it is determined that the moment when the channel is idle is the same as the start moment of the first candidate resource, the first reference signal is on the first candidate resource. Sent by.

  That is, the reference signal can be transmitted directly on the first candidate resource when the CCA result determines that the moment the channel is idle is the same as the start of the first candidate resource . The moment that the channel is idle is the same as the start of the first candidate resource, which does not mean an exact match of the numbers and the difference between the two is less than a preset threshold It should be understood that it may be considered that the moment when the channel congestion / idle state is determined to be idle is the same as the start moment of the first candidate resource.

  If it is determined that the instant that the channel is idle is before the start of the first candidate resource, a signal is sent to fill the vacancy to occupy the channel until the start of the first candidate resource And then the first reference signal begins to be transmitted on the first candidate resource.

  Optionally, in another embodiment, if the cell has finished performing CCA for data transmission and enters a random backoff process, the above data is transmitted to the UE or to another UE. It will be. If a flexible candidate resource for transmitting the reference signal is reached during the random backoff process for data transmission, the random backoff counter is stopped in this case at the beginning and the above for CCA for data transmission. The back-off counter is restarted only after the reference signal is completely transmitted. Alternatively, during the random backoff process for data transmission, if the starting point of the CCA that is initiated to transmit the reference signal is reached, i.e. in a pre-set time interval before the flexible candidate resource The CCA for transmitting the reference signal may be performed first. At the same time, the back-off counter for CCA for data transmission is temporarily stopped. If the CCA for the reference signal is successful, ie, the CCA result indicates that the channel is idle, the reference signal may be transmitted first. After the reference signal is transmitted, the above-described stopped counter is restarted. Alternatively, during the random backoff process for data transmission, if the starting point of the CCA that is initiated to transmit the reference signal is reached, i.e. in a pre-set time interval before the flexible candidate resource The CCA for data transmission and the CCA for reference signal transmission may be performed simultaneously. If the CCA for the reference signal is successful first, the reference signal may be transmitted first, in which case the backoff counter for the CCA for data transmission is stopped and the reference signal is completely Resume only after it has been sent. If the CCA for data transmission is first successful, data and reference signals may be transmitted.

  Optionally, in another embodiment, the first reference signal includes a reference signal used for cell synchronization. After the first reference signal is transmitted on the first candidate resource, when the first candidate resource occupies the corresponding amount of the last symbol in the time slot, the second reference signal is Sent at the beginning of the next time slot when the resource ends.

  Optionally, in another embodiment, when the first candidate resource does not occupy the corresponding amount of the last symbol of the time slot, the time slot is Until the end, and the second reference signal is transmitted at the beginning of the next time slot.

  The second reference signal includes one or more of a cell-specific reference signal CRS, channel state information-reference signal CSI-RS, or positioning reference signal PRS.

  For example, an example where the downlink transmission of a U-LTE system is based on Orthogonal Frequency Division Multiplexing Access (OFDMA) is used for illustration, where time-frequency resources are OFDM symbols in the time domain dimension. And is divided into OFDM subcarriers in the frequency domain dimension. FIG. 3 is a schematic diagram of time-frequency resources according to an embodiment of the present invention. As shown in FIG. 3, the minimum resource granularity is referred to as one resource element (RE), which indicates one OFDM symbol in the time domain and OFDM subcarrier in the frequency domain Shows the time-frequency grid points.

  As shown in FIG. 3, a preset resource is placed at the end of the first time slot of subframe 0. If the flexible candidate resource is not placed at the end of the time slot, and if the flexible candidate resource is successfully occupied to transmit the first reference signal, the signal filling the vacancy will occupy the channel At the beginning, then the CRS signal (second reference signal) is transmitted at the beginning of the next time slot. This ensures that the downlink data pattern does not change, and can further prevent the UE detection complexity from increasing.

  Alternatively, the flexible candidate resource may be selected directly to be at the end of the time slot, and then the CRS may be transmitted directly after the first reference signal is completely transmitted, , It is still possible to ensure that the downlink data pattern does not change, and to further prevent the UE detection complexity from increasing. In addition, since there is no need to send a signal to fill the vacancy, the system overhead may be reduced.

  Optionally, the second reference signal described above may be different from the current CRS, for example, the second reference signal is N consecutive symbols rather than the previous CRS occupying discontinuous symbols. May be CRS. In particular, the symbols where CRS is placed and within 14 symbols of one current subframe are symbols 0, 4, 7, and 11, and the symbols where the modified CRS is placed are symbols 7, 8 , 9, and 10. The PSS / SSS is on symbols 5 and 6, and the CRS on each symbol may be in the same position as the original CRS on each symbol or may undergo a frequency-domain subcarrier shift. Assumed in the book. The advantage of the above is that the channel can continue to be occupied and the channel is not previously occupied by another strongly interfering node during this time. Furthermore, the time domain resource overhead may be further reduced compared to the original solution for CRS occupying non-contiguous symbols. Since CRS occupies continuous time domain symbols, signal detection performance can be further enhanced. In this case, sending PSS / SSS may even be canceled, instead, only CRS is sent to perform cell identification and measurement.

  Optionally, in another embodiment, the flexible candidate resource is a resource that is obtained after a preset resource has been transformed in time in the forward or reverse direction.

  Optionally, in another embodiment, the temporal conversion granularity is one or more time slots.

  Optionally, in another embodiment, the flexible candidate resource occupies a corresponding amount of the last symbol in a time slot within the time window.

  For example, assuming that a flexible candidate resource occupies two symbols in the time domain, the flexible candidate resource is a resource corresponding to the last two symbols of a time slot in the time window.

  Optionally, in another embodiment, the time window is the same as the time window in which the flexible candidate resources used by neighboring cells of the same frequency to transmit the first reference signal are placed.

  For example, multiple U-LTE secondary serving cells of the same frequency may select the same time window. That is, the length of the time window and the appearing period of all U-LTE secondary serving cells are the same. Thus, the UE may identify and measure all cells of frequency as much as possible within the time window, which reduces UE measurement complexity and UE power consumption. Furthermore, coordination between all U-LTE secondary serving cells is also guaranteed.

  FIG. 4 is a schematic flowchart of a method for transmitting a reference signal in a cell using an unlicensed frequency band according to another embodiment of the present invention. The method shown in FIG. 4 may be performed by a UE, and the method includes:

  401. Determine a time window in which a candidate resource set to be used when the first reference signal is transmitted in a cell that uses an unlicensed frequency band, the candidate resource set includes a preconfigured resource and Including at least one flexible candidate resource, the pre-configured resource is within the time window and is required to transmit the first reference signal according to the first period when the cell is in the active state A flexible candidate resource is a resource that is within a time window and is acquired after a preset resource is temporally converted, and the period in which the time window appears is the second period The second period is longer than the first period.

  For example, systems that perform communication using an unlicensed frequency band include LTE systems U-LTE, WLAN systems, and the like that are deployed in unlicensed frequency bands. For example, to increase service capacity, carrier aggregation is generally performed on the U-LTE serving cell and the primary serving cell that serve the UE, which is used as a secondary serving cell on the unlicensed spectrum. And the primary serving cell is deployed on the spectrum that needs to be licensed.

  When serving a UE, a secondary serving cell using an unlicensed frequency band generally needs to send some reference signals to the UE for cell identification, cell synchronization, channel measurement, interference measurement, etc. There is. However, during the process of transmitting a reference signal to the UE by occupying a preset resource according to a preset period, when the channel is occupied due to LBT specification limitations, May not be completed.

  According to the method of this embodiment of the present invention, determining a candidate resource set for transmitting a reference signal increases the transmission opportunity of the reference signal, which further increases the success rate of transmission of the reference signal. be able to. The candidate resource set includes a preset resource and at least one flexible candidate resource. The flexible candidate resource and the preconfigured resource use the same frequency, which means that the flexible candidate resource is a resource that is acquired after the preconfigured resource is temporally transformed . In addition, flexible candidate resources need to fall within a time window that appears periodically.

  In particular, the second period in which the time window appears is longer than the preset first period for transmitting the reference signal. For example, the first period can be 5 ms and the second period is 40 ms or 80 ms. It should be understood that these examples are intended only to help those skilled in the art to better understand this embodiment of the invention and are not intended to limit the scope of this embodiment of the invention. . The length of the time window may be determined with reference to status such as channel congestion level, which is not limited in this embodiment of the invention.

  Therefore, the UE may first determine the time window (such as the length of the time window and the period of time it appears) where the flexible candidate resource is placed, and further know when the first reference signal needs to be detected there is a possibility.

  402. Detect first reference signal on unlicensed frequency band in time window.

  For example, when multiple neighboring cells using the same frequency (such as a U-LTE secondary serving cell) use the same time window, the first reference signal transmitted by multiple neighboring cells can be detected simultaneously There is sex.

  Based on the above technical solution, in this embodiment of the present invention, a candidate resource set is determined for transmitting the reference signal in order to increase the transmission opportunity of the reference signal. Thus, according to this embodiment of the present invention, the success rate of the transmission of the reference signal can be increased without affecting the normal system communication.

  Further, when the reference signal is transmitted in a communication system using an unlicensed spectrum, the solution provided in this embodiment of the present invention meets the requirements for cell synchronization and CSI measurement, and the UE demodulation and Mobility performance can be further guaranteed.

  In addition, the mainstream deployment scenario of this embodiment of the present invention performs carrier aggregation on a primary serving cell on a spectrum that requires a license and a U-LTE secondary serving cell on a spectrum that does not require a license to use. It is to be. The LTE primary serving cell and the U-LTE secondary serving cell may be deployed at the same location or may be deployed at different locations, and an ideal backhaul path exists between the two serving cells.

  Alternatively, in the present invention, deployment does not have an ideal backhaul path between the two serving cells, for example, the backhaul delay is relatively large and then information is quickly transferred between the two serving cells. May be performed in scenarios that cannot be adjusted to Furthermore, U-LTE serving cells that can be accessed independently may also be deployed in this embodiment of the invention, i.e., in this case, carrier aggregation is performed for the U-LTE serving cell and the LTE serving cell. There is no need. The application scenario described above is intended only to help those skilled in the art to better understand this embodiment of the invention and is not intended to limit the scope of this embodiment of the invention.

  Optionally, in an embodiment, the first reference signal includes a reference signal used for cell synchronization. If the first reference signal is successfully detected after the first reference signal is detected on the unlicensed frequency band, the second reference signal is detected on the unlicensed frequency band. In time, the transmission resources occupied by the second reference signal are after the transmission resources occupied by the first reference signal, and the second reference signal is a cell-specific reference signal CRS, channel state information − One or more of the reference signal CSI-RS or the positioning reference signal PRS is included.

  For example, before the first reference signal is successfully detected, the UE may assume that the base station does not transmit the second reference signal, so the UE Do not perform detection or make any other corresponding preparation for the second reference signal. The UE performs detection of the second reference signal only after the first reference signal is successfully detected.

  It is assumed that the first reference signal is PSS / SSS. After detecting the PSS / SSS, the UE may determine the location of the resource of the second reference signal such as CRS based on the PSS / SSS. Optionally, PSS / SSS flexible candidate resources may be based on time-domain or subframe-level time domain transformations, ie, PSS / SSS flexible candidate resources May be on the last two symbols. Therefore, it may be determined that the CRS after the PSS / SSS occupies the entire time slot or subframe and the position of the CRS resource within the time slot or subframe is not changed, which is Does not affect data scheduling and transmission of another reference signal. That is, the UE assumes that there is a second reference signal after the detected PSS / SSS, i.e., there is no CRS before the detected PSS / SSS time domain position, which is , It may prevent the UE from performing blind detection regarding the presence of CRS.

  Optionally, in another embodiment, prior to determining a time window in which a flexible candidate resource to be used when the first reference signal is transmitted in a cell using an unlicensed frequency band is placed. Radio resource control (RRC) signaling transmitted by the base station is received, and the RRC signaling carries the length of the time window and the period of time it appears.

  Optionally, in another embodiment, the flexible candidate resource is a resource that is obtained after a preset resource has been transformed in time in the forward or reverse direction.

  Optionally, in another embodiment, the temporal conversion granularity is one or more time slots.

  Optionally, in another embodiment, the flexible candidate resource occupies a corresponding amount of the last symbol in a time slot within the time window.

  For example, assuming that a flexible candidate resource occupies two symbols in the time domain, the flexible candidate resource is a resource corresponding to the last two symbols of a time slot in the time window.

  Optionally, in another embodiment, the time window is the same as the time window in which the flexible candidate resources used by neighboring cells of the same frequency to transmit the first reference signal are placed.

  For example, multiple U-LTE secondary serving cells of the same frequency may select the same time window. That is, the length of the time window and the appearing period of all U-LTE secondary serving cells are the same. Thus, the UE may identify and measure all cells of frequency as much as possible within the time window, which reduces UE measurement complexity and UE power consumption. Furthermore, coordination between all U-LTE secondary serving cells is also guaranteed.

  FIG. 5 is a schematic block diagram of a base station according to an embodiment of the present invention. The base station shown in FIG. 5 includes a first determination unit 501, a second determination unit 502, and a transmission unit 503.

  The first determination unit 501 is configured to determine a candidate resource set to be used when the first reference signal is transmitted in a cell that uses an unlicensed frequency band, Including a configured resource and at least one flexible candidate resource, the preconfigured resource is within a time window and for transmitting a first reference signal according to a first period when the cell is in an active state The flexible candidate resource is within the time window, is a candidate resource obtained after a preset resource is temporally converted, and the period in which the time window appears is The second period is longer than the first period.

  It should be understood that an active cell is a relative concept to a dormant cell. Active cells transmit reference signals more frequently to the UE, while dormant cells transmit reference signals less frequently. For example, an active cell transmits a PSS / SSS signal once every 5 ms, while a dormant cell transmits a PSS / SSS signal once every 40 ms or 80 ms.

  For example, a system that performs communication using an unlicensed frequency band includes an LTE system U-LTE deployed in an unlicensed frequency band, a wireless local area network (WLAN) system, and the like. For example, to increase service capacity, carrier aggregation is generally performed on the U-LTE serving cell and the primary serving cell that serve the UE, which is used as a secondary serving cell on the unlicensed spectrum. And the primary serving cell is deployed on the spectrum that needs to be licensed.

  When serving a UE, a secondary serving cell using an unlicensed frequency band generally needs to send some reference signals to the UE for cell identification, cell synchronization, channel measurement, interference measurement, etc. There is. However, during the process of transmitting a reference signal to the UE by occupying a preset resource according to a preset period, when the channel is occupied due to LBT specification limitations, May not be completed.

  According to the method of this embodiment of the present invention, determining a candidate resource set for transmitting a reference signal increases the transmission opportunity of the reference signal, which further increases the success rate of transmission of the reference signal. be able to. The candidate resource set includes a preset resource and at least one flexible candidate resource. The flexible candidate resource and the preconfigured resource use the same frequency, which means that the flexible candidate resource is a resource that is acquired after the preconfigured resource is temporally transformed . In addition, flexible candidate resources need to fall within a time window that appears periodically.

  In particular, the second period in which the time window appears is longer than the preset first period for transmitting the reference signal. For example, the first period can be 5 ms and the second period is 40 ms or 80 ms. It should be understood that these examples are intended only to help those skilled in the art to better understand this embodiment of the invention and are not intended to limit the scope of this embodiment of the invention. . The length of the time window may be determined with reference to status such as channel congestion level, which is not limited in this embodiment of the invention.

  The second determination unit 502 is configured to determine a first candidate resource to be used when the first reference signal is transmitted in a cell that uses an unlicensed frequency band, and the first candidate The channel on the unlicensed frequency band corresponding to the resource is in an idle state, and the first candidate resource is a preset resource or a flexible candidate resource in the candidate resource set.

  The transmission unit 503 is configured to transmit the first reference signal on the first candidate resource.

  For example, channel congestion / idle states of preset resources and flexible candidate resources may be determined in chronological order. This time there are a total of three resources available to transmit the reference signal, and the temporal order of these three resources is the first flexible candidate resource, the preset resource, and the first It is assumed that there are two flexible candidate resources.

  Therefore, it may be determined first whether the channel on the first flexible candidate resource is idle, and if the channel is idle, the reference signal is on the first flexible candidate resource. (In this case, the first flexible candidate resource is the first candidate resource). Conversely, if the channel on the first flexible candidate resource is congested, it must be further determined if the channel on the pre-configured resource is idle and the channel is idle In this case, the reference signal is transmitted on a preset resource. Conversely, if the channel on the pre-configured resource is congested, it needs to be further determined if the channel on the second flexible candidate resource is idle and the channel is idle The reference signal is transmitted on the second flexible candidate resource (in this case, the second flexible candidate resource is the first candidate resource). Conversely, if the channel on the second flexible candidate resource is congested, the first reference signal cannot be transmitted on the second flexible candidate resource, i.e., the current first reference signal. Transmission fails.

  Based on the above technical solution, in this embodiment of the present invention, a candidate resource set is determined for transmitting the reference signal in order to increase the transmission opportunity of the reference signal. Thus, according to this embodiment of the present invention, the success rate of the transmission of the reference signal can be increased without affecting the normal system communication.

  Further, when the reference signal is transmitted in a communication system using an unlicensed spectrum, the solution provided in this embodiment of the present invention meets the requirements for cell synchronization and CSI measurement, and the UE demodulation and Mobility performance can be further guaranteed.

  In addition, the mainstream deployment scenario of this embodiment of the present invention performs carrier aggregation on a primary serving cell on a spectrum that requires a license and a U-LTE secondary serving cell on a spectrum that does not require a license to use. It is to be. The LTE primary serving cell and the U-LTE secondary serving cell may be deployed at the same location or may be deployed at different locations, and an ideal backhaul path exists between the two serving cells.

  Alternatively, in the present invention, deployment does not have an ideal backhaul path between the two serving cells, for example, the backhaul delay is relatively large and then information is quickly transferred between the two serving cells. May be performed in scenarios that cannot be adjusted to Furthermore, U-LTE serving cells that can be accessed independently may also be deployed in this embodiment of the invention, i.e., in this case, carrier aggregation is performed for the U-LTE serving cell and the LTE serving cell. There is no need. The application scenario described above is intended only to help those skilled in the art to better understand this embodiment of the invention and is not intended to limit the scope of this embodiment of the invention.

  Optionally, in an embodiment, the second decision unit 502 initiates CCA for an unlicensed frequency band in a pre-set time interval before the first candidate resource to obtain a free channel assessment CCA result Especially configured to do. Then, it is determined from the CCA result that the channel on the unlicensed frequency band corresponding to the first candidate resource is in the idle state.

  Optionally, in another embodiment, the second decision unit 502 may idle a channel on the unlicensed frequency band corresponding to the first candidate resource when the CCA result indicates that the channel is idle. Random backoff is performed when it is determined that the channel is idle or the CCA result indicates that the channel is idle, and the first when the channel is still idle within the random backoff time period. It is specifically configured to determine that the channel on the unlicensed frequency band corresponding to the candidate resource is in an idle state.

  Thus, when the CCA result indicates that the channel is idle, the first reference signal is transmitted directly on the first candidate resource, but no random backoff is performed, which is And the success rate of the reference signal transmission can be increased.

  Alternatively, random backoff is performed first when the CCA result indicates that the channel is idle. The first reference signal is transmitted on the first candidate resource only when the channel is still idle within the random backoff time period. This can protect the signal transmission of another communication device in the system and prevent mutual interference between the transmission of the reference signal of the cell and the signal transmission of another communication device.

  Optionally, the starting point for starting the above-described CCA may be the start of the first subframe within the time window, in which case the above-mentioned preset time interval is 5 symbols . Alternatively, the preset time interval described above is equal to the current maximum backoff time, for example, the length of the CCA unit time multiplied by the maximum value in the range of backoff counter values. It may be the length of the contention window in the backoff mechanism. It should be noted that these examples are only intended to help those skilled in the art to better understand this embodiment of the invention and are not intended to limit the scope of this embodiment of the invention. .

  Optionally, in another embodiment, the transmitting unit 503 determines that the first on the first candidate resource if it is determined that the moment when the channel is idle is the same as the start of the first candidate resource. Is specifically configured to transmit the reference signal.

  That is, the reference signal can be transmitted directly on the first candidate resource when the CCA result determines that the moment the channel is idle is the same as the start of the first candidate resource . The moment that the channel is idle is the same as the start of the first candidate resource, which does not mean an exact match of the numbers and the difference between the two is less than a preset threshold It should be understood that it may be considered that the moment when the channel congestion / idle state is determined to be idle is the same as the start moment of the first candidate resource.

  Alternatively, if it is determined that the moment when the channel is idle is before the start of the first candidate resource, free space is occupied to occupy the channel until the start of the first candidate resource. The fill signal is transmitted, and then the first reference signal begins to be transmitted on the first candidate resource.

  Optionally, in another embodiment, the first reference signal includes a reference signal used for cell synchronization. Transmit unit 503 transmits the second reference signal at the beginning of the next time slot when the first candidate resource ends when the first candidate resource occupies the corresponding amount of the last symbol of the time slot Further configured to.

  The second reference signal includes one or more of a cell-specific reference signal CRS, channel state information-reference signal CSI-RS, or positioning reference signal PRS.

  Optionally, in another embodiment, the first reference signal includes a reference signal used for cell synchronization. When the first candidate resource does not occupy the corresponding amount of the last symbol in the time slot, the transmission unit 503 transmits a signal that fills the space until the time slot ends when the first candidate resource ends. Is further configured to transmit the second reference signal at the beginning of each of the time slots.

  The second reference signal includes one or more of a cell-specific reference signal CRS, channel state information-reference signal CSI-RS, or positioning reference signal PRS.

  Optionally, in another embodiment, the flexible candidate resource is a resource that is obtained after a preset resource has been transformed in time in the forward or reverse direction.

  Optionally, in another embodiment, the temporal conversion granularity is one or more time slots.

  Optionally, in another embodiment, the flexible candidate resource occupies a corresponding amount of the last symbol in a time slot within the time window.

  For example, assuming that a flexible candidate resource occupies two symbols in the time domain, the flexible candidate resource is a resource corresponding to the last two symbols of a time slot in the time window.

  Optionally, in another embodiment, the time window is the same as the time window in which the flexible candidate resources used by neighboring cells of the same frequency to transmit the first reference signal are placed.

  For example, multiple U-LTE secondary serving cells of the same frequency may select the same time window. That is, the length of the time window and the appearing period of all U-LTE secondary serving cells are the same. Thus, the UE may identify and measure all cells of frequency as much as possible within the time window, which reduces UE measurement complexity and UE power consumption. Furthermore, coordination between all U-LTE secondary serving cells is also guaranteed.

  FIG. 6 is a schematic block diagram of a user equipment according to an embodiment of the present invention. The user equipment shown in FIG. 6 includes a determination unit 601 and a detection unit 602.

  The determining unit 601 is configured to determine a time window in which a candidate resource set to be used when the first reference signal is transmitted in a cell that uses an unlicensed frequency band, Including a preset resource and at least one flexible candidate resource, wherein the preset resource is within a time window and transmits a first reference signal according to a first period when the cell is in an active state A flexible candidate resource is a candidate resource that is acquired after a preset resource is temporally converted, and a period in which the time window appears is a resource that is required to , The second period, and the second period is longer than the first period.

  For example, systems that perform communication using an unlicensed frequency band include LTE systems U-LTE, WLAN systems, and the like that are deployed in unlicensed frequency bands. For example, to increase service capacity, carrier aggregation is generally performed on the U-LTE serving cell and the primary serving cell that serve the UE, which is used as a secondary serving cell on the unlicensed spectrum. And the primary serving cell is deployed on the spectrum that needs to be licensed.

  When serving a UE, a secondary serving cell using an unlicensed frequency band generally needs to send some reference signals to the UE for cell identification, cell synchronization, channel measurement, interference measurement, etc. There is. However, during the process of transmitting a reference signal to the UE by occupying a preset resource according to a preset period, when the channel is occupied due to LBT specification limitations, May not be completed.

  According to the method of this embodiment of the present invention, determining a candidate resource set for transmitting a reference signal increases the transmission opportunity of the reference signal, which further increases the success rate of transmission of the reference signal. be able to. The candidate resource set includes a preset resource and at least one flexible candidate resource. The flexible candidate resource and the preconfigured resource use the same frequency, which means that the flexible candidate resource is a resource that is acquired after the preconfigured resource is temporally transformed . In addition, flexible candidate resources need to fall within a time window that appears periodically.

  In particular, the second period in which the time window appears is longer than the preset first period for transmitting the reference signal. For example, the first period can be 5 ms and the second period is 40 ms or 80 ms. It should be understood that these examples are intended only to help those skilled in the art to better understand this embodiment of the invention and are not intended to limit the scope of this embodiment of the invention. . The length of the time window may be determined with reference to status such as channel congestion level, which is not limited in this embodiment of the invention.

  Therefore, the UE may first determine the time window (such as the length of the time window and the period of time it appears) where the flexible candidate resource is placed, and further know when the first reference signal needs to be detected there is a possibility.

  The detection unit 602 is configured to detect a first reference signal on an unlicensed frequency band within the time window.

  For example, when multiple neighboring cells using the same frequency (such as a U-LTE secondary serving cell) use the same time window, the first reference signal transmitted by multiple neighboring cells can be detected simultaneously There is sex.

  Based on the above technical solution, in this embodiment of the present invention, a candidate resource set is determined for transmitting the reference signal in order to increase the transmission opportunity of the reference signal. Thus, according to this embodiment of the present invention, the success rate of the transmission of the reference signal can be increased without affecting the normal system communication.

  Further, when the reference signal is transmitted in a communication system using an unlicensed spectrum, the solution provided in this embodiment of the present invention meets the requirements for cell synchronization and CSI measurement, and the UE demodulation and Mobility performance can be further guaranteed.

  In addition, the mainstream deployment scenario of this embodiment of the present invention performs carrier aggregation on a primary serving cell on a spectrum that requires a license and a U-LTE secondary serving cell on a spectrum that does not require a license to use. It is to be. The LTE primary serving cell and the U-LTE secondary serving cell may be deployed at the same location or may be deployed at different locations, and an ideal backhaul path exists between the two serving cells.

  Alternatively, in the present invention, deployment does not have an ideal backhaul path between the two serving cells, for example, the backhaul delay is relatively large and then information is quickly transferred between the two serving cells. May be performed in scenarios that cannot be adjusted to Furthermore, U-LTE serving cells that can be accessed independently may also be deployed in this embodiment of the invention, i.e., in this case, carrier aggregation is performed for the U-LTE serving cell and the LTE serving cell. There is no need. The application scenario described above is intended only to help those skilled in the art to better understand this embodiment of the invention and is not intended to limit the scope of this embodiment of the invention.

  Optionally, in an embodiment, the first reference signal includes a reference signal used for cell synchronization. The detection unit 602 is further configured to detect a second reference signal on the unlicensed frequency band if the first reference signal is successfully detected, and temporally by the second reference signal The occupied transmission resource is after the transmission resource occupied by the first reference signal, and the second reference signal is a cell-specific reference signal CRS, channel state information-reference signal CSI-RS, or positioning reference signal Contains one or more of the PRS.

  For example, before the first reference signal is successfully detected, the UE may assume that the base station does not transmit the second reference signal, so the UE Do not perform detection or make any other corresponding preparation for the second reference signal. The UE performs detection of the second reference signal only after the first reference signal is successfully detected.

  It is assumed that the first reference signal is PSS / SSS. After detecting the PSS / SSS, the UE may determine the location of the resource of the second reference signal such as CRS based on the PSS / SSS. Optionally, PSS / SSS flexible candidate resources may be based on time-domain or subframe-level time domain transformations, ie, PSS / SSS flexible candidate resources May be on the last two symbols. Therefore, it may be determined that the CRS after the PSS / SSS occupies the entire time slot or subframe and the position of the CRS resource within the time slot or subframe is not changed, which is Does not affect data scheduling and transmission of another reference signal. That is, the UE assumes that there is a second reference signal after the detected PSS / SSS, i.e., there is no CRS before the detected PSS / SSS time domain position, which is , It may prevent the UE from performing blind detection regarding the presence of CRS.

  Optionally, in another embodiment, the user equipment further includes a receiving unit 603 configured to receive radio resource control RRC signaling transmitted by the base station, wherein the RRC signaling is a time window length and appears Carry period.

  Optionally, in another embodiment, the flexible candidate resource is a resource that is obtained after a preset resource has been transformed in time in the forward or reverse direction.

  Optionally, in another embodiment, the temporal conversion granularity is one or more time slots.

  Optionally, in another embodiment, the flexible candidate resource occupies a corresponding amount of the last symbol in a time slot within the time window.

  For example, assuming that a flexible candidate resource occupies two symbols in the time domain, the flexible candidate resource is a resource corresponding to the last two symbols of a time slot in the time window.

  Optionally, in another embodiment, the time window is the same as the time window in which the flexible candidate resources used by neighboring cells of the same frequency to transmit the first reference signal are placed.

  For example, multiple U-LTE secondary serving cells of the same frequency may select the same time window. That is, the length of the time window and the appearing period of all U-LTE secondary serving cells are the same. Thus, the UE may identify and measure all cells of frequency as much as possible within the time window, which reduces UE measurement complexity and UE power consumption. Furthermore, coordination between all U-LTE secondary serving cells is also guaranteed.

  FIG. 7 is a schematic block diagram of a base station according to another embodiment of the present invention. The base station 70 of FIG. 7 may be configured to implement the steps and methods of the method embodiments described above. In the embodiment of FIG. 7, the base station 70 includes an antenna 701, a transmitter 702, a receiver 703, a processor 704, and a memory 705. The processor 704 may be configured to control the operation of the base station 70 and process signals. Memory 705 may include read only memory and random access memory and provides instructions and data for processor 704. Transmitter 702 and receiver 703 may be coupled to antenna 701. All components of base station 70 are coupled together by using bus system 706, which includes a power bus, a control bus, and a status signal bus in addition to a data bus. However, for clarity of illustration, various buses are shown as bus system 706 in the figure.

In particular, the memory 705 has the following process:
Determining a candidate resource set to be used when a first reference signal is transmitted in a cell using an unlicensed frequency band, the candidate resource set comprising a preconfigured resource and at least one A resource that is required to transmit the first reference signal according to the first period when the preset resource is within the time window and the cell is in the active state, including flexible candidate resources The flexible candidate resource is in the time window, the candidate resource is acquired after the preset resource is temporally converted, the period in which the time window appears is the second period, Determining that the period is longer than the first period;
Determining a first candidate resource to be used when the first reference signal is transmitted in a cell using an unlicensed frequency band, the unlicensed frequency corresponding to the first candidate resource Determining that the channel on the band is in an idle state and the first candidate resource is a preconfigured resource or a flexible candidate resource in a candidate resource set;
Instructions may be stored to perform transmitting the first reference signal on the first candidate resource.

  Based on the above technical solution, in this embodiment of the present invention, a candidate resource set is determined for transmitting the reference signal in order to increase the transmission opportunity of the reference signal. Thus, according to this embodiment of the present invention, the success rate of the transmission of the reference signal can be increased without affecting the normal system communication.

  Further, when the reference signal is transmitted in a communication system using an unlicensed spectrum, the solution provided in this embodiment of the present invention meets the requirements for cell synchronization and CSI measurement, and the UE demodulation and Mobility performance can be further guaranteed.

  In addition, the mainstream deployment scenario of this embodiment of the present invention performs carrier aggregation on a primary serving cell on a spectrum that requires a license and a U-LTE secondary serving cell on a spectrum that does not require a license to use. It is to be. The LTE primary serving cell and the U-LTE secondary serving cell may be deployed at the same location or may be deployed at different locations, and an ideal backhaul path exists between the two serving cells.

  Alternatively, in the present invention, deployment does not have an ideal backhaul path between the two serving cells, for example, the backhaul delay is relatively large and then information is quickly transferred between the two serving cells. May be performed in scenarios that cannot be adjusted to Furthermore, U-LTE serving cells that can be accessed independently may also be deployed in this embodiment of the invention, i.e., in this case, carrier aggregation is performed for the U-LTE serving cell and the LTE serving cell. There is no need. The application scenario described above is intended only to help those skilled in the art to better understand this embodiment of the invention and is not intended to limit the scope of this embodiment of the invention.

Optionally, in one embodiment, the memory 705 is the following process:
In order to obtain the result of the free channel assessment CCA, the CCA results for the unlicensed frequency band in the preset time interval before the first candidate resource, and the CCA result determines the first candidate resource Instructions may be further stored for performing determining that the corresponding channel on the unlicensed frequency band is idle.

Optionally, in another embodiment, the memory 705 is the following process:
Determining that the channel on the unlicensed frequency band corresponding to the first candidate resource is idle when the CCA result indicates that the channel is idle, or
Random backoff is performed when the CCA results indicate that the channel is idle, and when the channel is still idle within the random backoff time period, the unlicensed corresponding to the first candidate resource Instructions may also be stored for performing determining that the channel on the frequency band is idle.

Optionally, in another embodiment, the memory 705 is the following process:
If it is determined that the moment when the channel is idle is the same as the start moment of the first candidate resource, transmitting the first reference signal on the first candidate resource, or if the channel is idle If it is determined that an instant is before the start of the first candidate resource, it sends a signal to fill the space to occupy the channel until the start of the first candidate resource, and then Instructions may be further stored for performing to start transmitting the first reference signal on one candidate resource.

  Optionally, in another embodiment, memory 705 may further include instructions for performing the following process.

  The first reference signal includes a reference signal used for cell synchronization, and after the first reference signal is transmitted on the first candidate resource, the first candidate resource corresponds to the time slot. When occupying the last symbol of the quantity, the second reference signal is transmitted at the beginning of the next time slot when the first candidate resource ends.

  The second reference signal includes one or more of a cell-specific reference signal CRS, channel state information-reference signal CSI-RS, or positioning reference signal PRS.

  Optionally, in another embodiment, memory 705 may further store instructions for performing the following process.

  The first reference signal includes a reference signal used for cell synchronization, and after the first reference signal is transmitted on the first candidate resource, the first candidate resource corresponds to the time slot. When not occupying the last symbol of the quantity, the signal filling the vacancy is transmitted until the end of the time slot when the first candidate resource ends, and the second reference signal is transmitted at the beginning of the next time slot. The

  The second reference signal includes one or more of a cell-specific reference signal CRS, channel state information-reference signal CSI-RS, or positioning reference signal PRS.

  Optionally, in another embodiment, memory 705 may further store instructions for performing the following process.

  A flexible candidate resource is a resource acquired after a preset resource is converted in the forward direction or the reverse direction in terms of time.

  Optionally, in another embodiment, memory 705 may further store instructions for performing the following process.

  The granularity of temporal conversion is one or more time slots.

  Optionally, in another embodiment, memory 705 may further store instructions for performing the following process.

  A flexible candidate resource occupies a corresponding amount of the last symbol in a time slot within the time window.

  Optionally, in another embodiment, memory 705 may further store instructions for performing the following process.

  The time window is the same as the time window in which flexible candidate resources used by neighboring cells of the same frequency to transmit the first reference signal are placed.

  FIG. 8 is a schematic block diagram of user equipment according to another embodiment of the present invention. The user equipment 80 of FIG. 8 may be configured to implement the steps and methods of the method embodiments described above. In the embodiment of FIG. 8, user equipment 80 includes an antenna 801, a transmitter 802, a receiver 803, a processor 804, and a memory 805. The processor 804 may be configured to control the operation of the base station 80 and process the signal. Memory 805 may include read-only memory and random access memory and provides instructions and data for processor 804. Transmitter 802 and receiver 803 may be coupled to antenna 801. All components of the base station 80 are coupled together by using a bus system 806, which includes a power bus, a control bus, and a status signal bus in addition to a data bus. However, for clarity of explanation, the various buses are shown as bus system 806 in the figure.

In particular, the memory 805 determines the time window in which the candidate resource set to be used is placed in the following process: the first reference signal is transmitted in a cell that uses an unlicensed frequency band. The candidate resource set includes a preconfigured resource and at least one flexible candidate resource, the preconfigured resource is within a time window and according to a first period when the cell is in an active state It is a resource required for transmitting the first reference signal, a flexible candidate resource is in the time window, and is a candidate resource acquired after a preset resource is temporally converted Determining that the time period in which the time window appears is the second period, and the second period is longer than the first period;
Instructions for performing a first reference signal on the unlicensed frequency band within the time window may be stored.

  Based on the above technical solution, in this embodiment of the present invention, a candidate resource set is determined for transmitting the reference signal in order to increase the transmission opportunity of the reference signal. Thus, according to this embodiment of the present invention, the success rate of the transmission of the reference signal can be increased without affecting the normal system communication.

  Further, when the reference signal is transmitted in a communication system using an unlicensed spectrum, the solution provided in this embodiment of the present invention meets the requirements for cell synchronization and CSI measurement, and the UE demodulation and Mobility performance can be further guaranteed.

  In addition, the mainstream deployment scenario of this embodiment of the present invention performs carrier aggregation on a primary serving cell on a spectrum that requires a license and a U-LTE secondary serving cell on a spectrum that does not require a license to use. It is to be. The LTE primary serving cell and the U-LTE secondary serving cell may be deployed at the same location or may be deployed at different locations, and an ideal backhaul path exists between the two serving cells.

  Alternatively, in the present invention, deployment does not have an ideal backhaul path between the two serving cells, for example, the backhaul delay is relatively large and then information is quickly transferred between the two serving cells. May be performed in scenarios that cannot be adjusted to Furthermore, U-LTE serving cells that can be accessed independently may also be deployed in this embodiment of the invention, i.e., in this case, carrier aggregation is performed for the U-LTE serving cell and the LTE serving cell. There is no need. The application scenario described above is intended only to help those skilled in the art to better understand this embodiment of the invention and is not intended to limit the scope of this embodiment of the invention.

  Optionally, in embodiments, memory 805 may further store instructions for performing the following processes.

  The first reference signal contains the reference signal used for cell synchronization, and after the first reference signal is detected on the unlicensed frequency band, the first reference signal is successfully detected The second reference signal is detected on an unlicensed frequency band, and in time, the transmission resource occupied by the second reference signal is greater than the transmission resource occupied by the first reference signal. Later, the second reference signal includes one or more of a cell specific reference signal CRS, a channel state information-reference signal CSI-RS, or a positioning reference signal PRS.

Optionally, in another embodiment, the memory 805 is the following process:
Radio resource control RRC signaling transmitted by the base station prior to determining the time window in which the candidate resource set to be used is placed when the first reference signal is transmitted in a cell using an unlicensed frequency band The RRC signaling may further store instructions for performing the receiving, carrying the length of the time window and the period of time it appears.

  Optionally, in another embodiment, memory 805 may further store instructions for performing the following process.

  A flexible candidate resource is a resource acquired after a preset resource is converted in the forward direction or the reverse direction in terms of time.

  Optionally, in another embodiment, memory 805 may further store instructions for performing the following process.

  The granularity of temporal conversion is one or more time slots.

  Optionally, in another embodiment, memory 805 may further store instructions for performing the following process.

  A flexible candidate resource occupies a corresponding amount of the last symbol in a time slot within the time window.

  Optionally, in another embodiment, memory 805 may further store instructions for performing the following process.

  The time window is the same as the time window in which flexible candidate resources used by neighboring cells of the same frequency to transmit the first reference signal are placed.

  It should be understood that the sequence numbers of the processes described above do not imply the order of execution in various embodiments of the present invention. The execution order of the processes should be determined according to the function and internal logic of the process, and should not be considered as any limitation to the implementation process of the embodiments of the present invention.

  Those skilled in the art know that in combination with the examples shown in the embodiments disclosed herein, the units and algorithm steps may be implemented by electronic hardware, computer software, or a combination thereof. There will be. To clearly show that hardware and software are interchangeable, the foregoing has generally described the structure and steps of each example according to function. Whether the function is performed by hardware or software depends on the specific application and the design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functionality for each particular application, but implementation should not be considered outside the scope of the present invention.

  For the sake of just a brief description, with respect to the detailed work processes of the above-described systems, devices, and units, reference may be made to the corresponding processes of the above-described method embodiments, and details are not described herein again. Will be clearly understood by those skilled in the art.

  It should be understood that in some embodiments provided in this application, the disclosed systems, devices, and methods may be implemented differently. For example, the described apparatus embodiment is merely exemplary. For example, the unit division is merely logical function division and may be other division in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be implemented through several interfaces. Indirect coupling or communication connections between devices or units may be implemented electronically, mechanically, or otherwise.

  Units described as separate parts may be physically separated or may not be physically separated, and parts shown as units may be physical units May or may not be a physical unit, may be located in one location, or distributed across multiple network units. Some or all of the units may be selected according to the actual need to achieve the objectives of the solutions of the embodiments of the present invention.

  In addition, the functional units of embodiments of the present invention may be integrated into one processing unit, or each of the units may exist physically independently, or at least two units Are integrated into one unit. The integrated unit may be implemented in the form of hardware or may be implemented in the form of a software functional unit.

  The integrated unit is implemented in the form of a software functional unit, and when sold or used as an independent product, the integrated unit may be stored on a computer-readable storage medium. Based on such understanding, the technical solution of the present invention may be basically implemented in the form of a software product, or contributes to the prior art or all or part of the technical solution. The part to do may be implemented in the form of a software product. A computer product (which may be a personal computer, server, or network device) that is stored on a storage medium and that performs all or part of the method steps described in the embodiments of the present invention. Includes some instructions to command. The above storage medium stores program codes such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk. Including any medium capable of.

  The foregoing descriptions are merely specific embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification or replacement readily figured out by a person skilled in the art within the technical scope disclosed in the present invention shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

70 base station
80 User equipment
501 1st decision unit
502 2nd decision unit
503 transmission unit
601 decision unit
602 detection unit
603 receiver unit
701 antenna
702 transmitter
703 receiver
704 processor
705 memory
706 Bus system
801 antenna
802 transmitter
803 receiver
804 processor
805 memory

Claims (34)

A method for transmitting a reference signal in a cell using an unlicensed frequency band, comprising:
Determining a candidate resource set to be used when a first reference signal is transmitted in the cell using the unlicensed frequency band, wherein the candidate resource set is a pre-configured resource and Necessary for transmitting the first reference signal according to a first period when the pre-configured resource is within a time window and the cell is in an active state, including at least one flexible candidate resource The flexible candidate resource is within the time window, the candidate resource is acquired after the preset resource is temporally converted, and a period in which the time window appears A second period, wherein the second period is longer than the first period; and
Determining a first candidate resource to be used when the first reference signal is transmitted in the cell using the unlicensed frequency band, corresponding to the first candidate resource The channel on the unlicensed frequency band is in an idle state, and the first candidate resource is the preset resource or a flexible candidate resource in the candidate resource set;
Transmitting the first reference signal on the first candidate resource. Determining a first candidate resource to be used when the first reference signal is transmitted in the cell using the unlicensed frequency band, corresponding to the first candidate resource The channel on the unlicensed frequency band is in an idle state,
Initiating the CCA for the unlicensed frequency band at a preset time interval before the first candidate resource to obtain a free channel assessment CCA result;
2. The method of claim 1, comprising: determining, based on the result of the CCA, that the channel on the unlicensed frequency band corresponding to the first candidate resource is in the idle state. According to the result of the CCA, determining that the channel on the unlicensed frequency band corresponding to the first candidate resource is in the idle state,
Determining that the channel on the unlicensed frequency band corresponding to the first candidate resource is in the idle state when the result of the CCA indicates that the channel is idle; or When the result of CCA indicates that the channel is idle, a random backoff is performed, and when the channel is still idle within the random backoff time period, the first candidate resource 3. The method of claim 2, comprising determining that the channel on the corresponding unlicensed frequency band is in the idle state. The step of transmitting the first reference signal on the first candidate resource;
Transmitting the first reference signal on the first candidate resource, if it is determined that the moment when the channel is in the idle state is the same as the start moment of the first candidate resource, or If it is determined that the instant that the channel is in the idle state is before the start time of the first candidate resource, to occupy the channel until the start time of the first candidate resource 4. The method of claim 3, comprising transmitting a signal to fill a vacancy and then starting to transmit the first reference signal on the first candidate resource. After the first reference signal includes a reference signal used for cell synchronization and transmitting the first reference signal on the first candidate resource, the method includes the first candidate Further comprising transmitting a second reference signal at the beginning of the next time slot when the first candidate resource ends when the resource occupies a corresponding amount of the last symbol of the time slot;
5. The second reference signal according to any one of claims 1 to 4, wherein the second reference signal includes one or more of a cell-specific reference signal CRS, a channel state information-reference signal CSI-RS, or a positioning reference signal PRS. the method of. After the first reference signal includes a reference signal used for cell synchronization and transmitting the first reference signal on the first candidate resource, the method comprises:
When the first candidate resource does not occupy the corresponding amount of the last symbol of the time slot, when the first candidate resource ends, it transmits a signal to fill the vacancy until the time slot ends, and the next time Further comprising transmitting a second reference signal at the beginning of the slot;
5. The second reference signal according to any one of claims 1 to 4, wherein the second reference signal includes one or more of a cell-specific reference signal CRS, a channel state information-reference signal CSI-RS, or a positioning reference signal PRS. the method of.   The method according to any one of claims 1 to 6, wherein the flexible candidate resource is a resource acquired after the preset resource is converted in the forward direction or the reverse direction in time.   The method according to any one of claims 1 to 7, wherein the granularity of temporal conversion is one or more time slots.   9. The method according to any one of claims 1 to 8, wherein the flexible candidate resource occupies a corresponding amount of trailing symbols of a time slot within the time window.   10. The time window according to any one of claims 1 to 9, wherein the time window is the same as a time window in which flexible candidate resources used by neighboring cells of the same frequency to transmit the first reference signal are placed. The method described. A method for transmitting a reference signal in a cell using an unlicensed frequency band, comprising:
Determining a time window in which a candidate resource set to be used when a first reference signal is transmitted in the cell using the unlicensed frequency band, wherein the candidate resource set is pre- The first reference signal according to a first period when the preset resource is within the time window and the cell is in an active state, comprising a configured resource and at least one flexible candidate resource The flexible candidate resource is within the time window, and is a candidate resource obtained after the preset resource is temporally converted, A period in which the time window appears is a second period, and the second period is longer than the first period; and
Detecting the first reference signal on the unlicensed frequency band within the time window. After the first reference signal includes a reference signal used for cell synchronization and detecting the first reference signal on the unlicensed frequency band, the method comprises:
If the first reference signal is successfully detected, detecting a second reference signal on the unlicensed frequency band, temporally occupied by the second reference signal The transmission resource is after the transmission resource occupied by the first reference signal, and the second reference signal is a cell-specific reference signal CRS, a channel state information-reference signal CSI-RS, or a positioning reference signal PRS. 12. The method of claim 11, further comprising a step comprising one or more of: Before determining a time window in which a candidate resource set to be used when a first reference signal is transmitted in the cell using the unlicensed frequency band, the method comprises:
13. A method according to claim 11 or 12, further comprising the step of receiving radio resource control RRC signaling sent by a base station, wherein the RRC signaling carries the length of the time window and the time period to appear.   14. The method according to any one of claims 11 to 13, wherein the flexible candidate resource is a resource obtained after the preset resource is converted in the forward direction or the reverse direction in time.   15. A method according to any one of claims 11 to 14, wherein the granularity of temporal conversion is one or more time slots.   16. The method according to any one of claims 11 to 15, wherein the flexible candidate resource occupies a corresponding amount of the last symbol of a time slot within the time window.   17. The time window according to any one of claims 11 to 16, wherein the time window is the same as a time window in which flexible candidate resources used by neighboring cells of the same frequency to transmit the first reference signal are placed. The method described. A first decision unit configured to determine a candidate resource set to be used when a first reference signal is transmitted in a cell using an unlicensed frequency band, the candidate resource set comprising: The first criterion according to a first period when the preset resource is within a time window and the cell is in an active state, comprising a preset resource and at least one flexible candidate resource A resource required to transmit a signal, the flexible candidate resource is within the time window, and the candidate resource is acquired after the preset resource is temporally converted, A period in which the time window appears is a second period; the second period is longer than the first period;
A second determination unit configured to determine a first candidate resource to be used when the first reference signal is transmitted in the cell using the unlicensed frequency band; The channel on the unlicensed frequency band corresponding to the first candidate resource is in an idle state, and the first candidate resource is the preset resource or a flexible candidate in the candidate resource set A resource, a second decision unit;
And a transmission unit configured to transmit the first reference signal on the first candidate resource. The second decision unit is
In order to obtain a free channel assessment CCA result, start the CCA for the unlicensed frequency band in a preset time interval before the first candidate resource;
19. The base station of claim 18, wherein the base station is specifically configured to determine, based on the result of the CCA, that the channel on the unlicensed frequency band corresponding to the first candidate resource is in the idle state. The second decision unit is
Determining that the channel on the unlicensed frequency band corresponding to the first candidate resource is in the idle state when the result of the CCA indicates that the channel is idle, or the CCA When the result of indicates that the channel is idle, a random backoff is performed, and when the channel is still idle within the random backoff time period, the first candidate resource is supported. 20. The base station of claim 19, wherein the base station is specifically configured to determine that the channel on the unlicensed frequency band is in the idle state. The transmitting unit is
If it is determined that the instant that the channel is in the idle state is the same as the start instant of the first candidate resource, transmit the first reference signal on the first candidate resource, or If it is determined that the moment when the channel is idle is before the start of the first candidate resource, there is a free space to occupy the channel until the start of the first candidate resource. 21. The base station of claim 20, wherein the base station is specifically configured to transmit a signal that fills and then start transmitting the first reference signal on the first candidate resource. The first reference signal includes a reference signal used for cell synchronization, and the transmission unit comprises:
When the first candidate resource occupies a corresponding amount of the last symbol of a time slot, a second reference signal is transmitted at the beginning of the next time slot when the first candidate resource ends Further configured,
The second reference signal includes one or more of a cell-specific reference signal CRS, a channel state information-reference signal CSI-RS, or a positioning reference signal PRS. Base station. The first reference signal includes a reference signal used for cell synchronization, and the transmission unit comprises:
When the first candidate resource does not occupy the corresponding amount of the last symbol of the time slot, when the first candidate resource ends, it transmits a signal to fill the vacancy until the time slot ends, and the next time Further configured to transmit a second reference signal at the beginning of the slot;
The second reference signal includes one or more of a cell-specific reference signal CRS, a channel state information-reference signal CSI-RS, or a positioning reference signal PRS. Base station.   The base station according to any one of claims 18 to 23, wherein the flexible candidate resource is a resource acquired after the preset resource is temporally converted in the forward direction or the reverse direction.   The base station according to any one of claims 18 to 24, wherein a granularity of temporal conversion is one or a plurality of time slots.   26. A base station according to any one of claims 18 to 25, wherein the flexible candidate resource occupies a corresponding amount of the last symbol of a time slot within the time window.   27. The time window according to any of claims 18 to 26, wherein the time window is the same as a time window in which flexible candidate resources used by neighboring cells of the same frequency to transmit the first reference signal are placed. The listed base station. A decision unit configured to determine a time window in which a candidate resource set to be used when a first reference signal is transmitted in a cell using an unlicensed frequency band, the candidate resource being The set includes a preset resource and at least one flexible candidate resource, wherein the preset resource is within the time window and the cell is in an active state according to a first period. Candidate resources that are required to transmit one reference signal, the flexible candidate resources are within the time window, and are acquired after the preset resource is temporally converted A period in which the time window appears is a second period, and the second period is longer than the first period;
A user equipment comprising: a detection unit configured to detect the first reference signal on the unlicensed frequency band within the time window. The first reference signal includes a reference signal used for cell synchronization, and the detection unit comprises:
If the first reference signal is successfully detected, it is further configured to detect a second reference signal on the unlicensed frequency band and is temporally occupied by the second reference signal. Transmission resource after the transmission resource occupied by the first reference signal, and the second reference signal is a cell-specific reference signal CRS, a channel state information-reference signal CSI-RS, or a positioning reference signal 30. The user equipment of claim 28, comprising one or more of the PRSs.   29. A receiving unit configured to receive radio resource control RRC signaling transmitted by a base station, wherein the RRC signaling further includes a receiving unit that carries a length of the time window and a time period to appear. Or user equipment according to 29.   31. The user equipment according to claim 28, wherein the flexible candidate resource is a resource acquired after the preset resource is converted in the forward direction or the reverse direction in time.   32. User equipment according to any one of claims 28 to 31, wherein the temporal conversion granularity is one or more time slots.   33. User equipment according to any one of claims 28 to 32, wherein the flexible candidate resource occupies a corresponding amount of the last symbol of a time slot within the time window.   The time window is the same as a time window in which flexible candidate resources used by neighboring cells of the same frequency to transmit the first reference signal are placed. User equipment as described.