CN109121214B

CN109121214B - Resource selection method and equipment in V2X communication

Info

Publication number: CN109121214B
Application number: CN201711160446.0A
Authority: CN
Inventors: 张世昌; 李迎阳; 王轶
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2017-06-23
Filing date: 2017-11-20
Publication date: 2023-11-24
Anticipated expiration: 2037-11-20
Also published as: CN109121214A

Abstract

The application discloses a method for selecting or reselecting resources in vehicle-to-outside (V2X) communication, which comprises the following steps: the UE determines a carrier set C which can be used for resource selection or reselection; the UE determines a candidate single subframe resource set S in a carrier set C; the UE selects at least one single subframe resource in the set S and transmits the PSSCH on the selected resource. The application also discloses a corresponding user equipment. The application can reduce half duplex limitation and IBE interference between different carriers in multi-carrier bypass communication by increasing the possibility of selecting frequency resources on the same subframe when UE performs resource selection or reselection on a plurality of carriers.

Description

Resource selection method and equipment in V2X communication

Technical Field

The present application relates to the field of communication technology, and in particular, to a method and apparatus for selecting resources, for example, in vehicle-to-outside (V2X) communication.

Background

In the 3GPP standard, the direct communication link between User Equipment (UE) to UE is referred to as bypass (Sidelink). Similar to the uplink and downlink, there are control channels and data channels on the bypass, the former referred to as bypass control channels (Physical Sidelink Control CHannel, abbreviated PSCCH) and the latter as bypass data channels (Physical Sidelink Shared CHannel, abbreviated PSSCH). The PSCCH is used to indicate a time-frequency domain resource location of PSSCH transmission, a modulation coding scheme, a priority of data carried in the PSSCH, and the like, and the PSSCH is used to carry data.

Control information and data in vehicle-to-outside (Vehicle to Vehicle/petestrian/Infrastructure/Network, abbreviated as V2X) communications may be transmitted through a bypass. The V2X communication includes two transmission modes at this time, namely, transmission Mode 3 (Mode 3) and transmission Mode 4 (Mode 4). For Mode 3, the PSCCH and PSSCH transmission resources of one UE (hereinafter collectively referred to as V2X UE) are allocated by a base station (hereinafter referred to as eNB), and the UE determines the PSCCH and PSSCH transmission resources by receiving a bypass resource allocation indication transmitted by the eNB through the PDCCH or EPDCCH. In Mode 4, the transmission resources of the PSCCH and the PSSCH are selected by the UE from the master according to the channel detection result.

If the UE adopting Mode 4 has V2X data to be transmitted in the subframe n (i.e. the time when the V2X data packet arrives at the UE radio access layer is not later than the subframe n) and the condition of resource selection or reselection is satisfied, the UE regards the time-frequency resources in the resource selection window [ n+t1, n+t2] of the current working carrier as candidate monocotyledonous frame resources (the values of T1 and T2 are determined by the UE implementation but the requirement that T1 is less than or equal to 4 and T2 is less than or equal to 20 is less than or equal to 100), and then the UE determines available candidate monocotyledonous frame resources in the resource selection window.

In the process of determining available candidate single-subframe resources, the UE firstly determines the time-frequency resource position and priority of the scheduled PSSCH of other UE by receiving PSCCH sent by other UE;

Then further detecting the demodulation reference channel received power (PSSCH-RSRP) of the scheduled PSSCH, and excluding resources for which the PSSCH-RSRP is higher than a predetermined threshold (hereinafter referred to as resource selection step 2);

then, the UE calculates the average received energy (S-RSSI) of the remaining resources, and the X% of the single subframe resources with the lowest S-RSSI are the available candidate single subframe resources (hereinafter referred to as resource selection step 3). In the 3GPP Rel-14 standard, the value of X is 20. It should be noted that the X% is the proportion of available candidate monocot frame resources to all the monocot frame resources in the resource selection window. The UE will randomly select one of the available candidate single subframe resources as the transmission resource.

In the V2X communication system defined by 3GPP Rel-14, the resource selection and resource reselection modes of the UE are only applicable to the single carrier operation mode. In order to improve V2X system throughput and system capacity, in the V2X evolution of 3GPP Rel-15, the goal of supporting multi-carrier bypass communication was introduced. In the above-mentioned multi-carrier bypass communication scenario, multiple carriers may belong to the same frequency band (frequency band), and in-band leakage Interference (IBE) and half-duplex limitation may be generated between multiple carriers belonging to the same frequency band. In addition, the UE may perform a transmitting or receiving operation on a plurality of carriers belonging to the same frequency band by using one transmitting or receiving radio frequency link, which eventually results in the number of transmitting or receiving radio frequency links of the UE being smaller than the number of carriers supported by the UE. Because the UE may select resources on multiple carriers simultaneously or transmit data on multiple carriers in parallel, channel conditions on multiple carriers may interact when the UE performs resource selection or resource reselection. It can be seen that in the multi-carrier bypass communication, when the UE performs resource selection or resource reselection, channel conditions on multiple carriers need to be comprehensively considered, and the resource selection and resource reselection mode designed for the single carrier working environment in 3GPP Rel-14 is no longer applicable.

From the above analysis, it can be seen that if multi-carrier bypass communication is to be supported, a way of improving UE resource selection or resource reselection is needed to better adapt to the multi-carrier bypass communication environment, and no reasonably efficient solution is currently available.

Disclosure of Invention

The application provides a method and equipment for performing resource selection or reselection in V2X communication, which are used for reducing half-duplex limitation and IBE interference among different carriers in multi-carrier bypass communication.

The application discloses a method for executing resource selection or reselection in vehicle-to-outside V2X communication, which comprises the following steps:

the User Equipment (UE) determines a carrier set C which can be used for resource selection or reselection;

the UE determines a candidate single subframe resource set S in a carrier set C;

the UE selects at least one single subframe resource in the set S and transmits a bypass data channel PSSCH on the selected resource.

Preferably, the carrier set C includes at least one carrier;

if the carrier set C contains at least two carriers, the configuration of the bypass synchronous signal SLSS sending sub-frames on the at least two carriers is the same;

or if the carrier set C includes at least two carriers, configurations of the transmission subframes of the bypass synchronization signals SLSS on the at least two carriers are different, and if the subframe x is a transmission subframe of the SLSS on any one of the carriers, the subframe x cannot be used for resource pool configuration on all the carriers;

Or if the carrier set C contains at least two carriers, the configuration of the SLSS transmission subframe and the configuration of the resource pool on each carrier in part or all of the carriers are independent from each other.

Preferably, the UE determining the candidate set of monocot frame resources S in the carrier set C includes:

defining a single subframe resource on any carrier C in the carrier set CFor subframe->L starting from subchannel x ^c _subCH A number of consecutive subchannels, wherein:

y represents a subframeA relative index within the resource pool;

L ^c _subCH indicating the number of sub-channels on carrier c for one PSSCH transmission, c=0, 1.

If the UE performs resource selection or reselection in subframe n, then [ n+T ] on carrier c ₁ ,n+T ₂ ]Continuous L on any one of subframes belonging to resource pool within range ^c _subCH The sub-channels are all candidate single subframe resources, wherein T ₁ And T ₂ Determination by UE implementation, recording that the total number of single subframe resources on wave c is The set of candidate single subframe resource components is S ^c The union set formed by the single-carrier single-subframe resource sets on each carrier in the carrier set C is the candidate single-subframe resource set S, wherein the single-carrier single-subframe resource means that sub-channels contained in the single-carrier single-subframe resource are all located on the same carrier.

Preferably, the UE selects at least one single subframe resource in the set S according to any one of the following methods:

the UE only selects one single-carrier single-subframe resource in the set S for data transmission, wherein the UE randomly selects one single-carrier single-subframe resource from the set S with medium probability; alternatively, the UE selects one carrier C at moderate probability among all carriers in the carrier set C and selects the same carrier C at set S ^c A single carrier single subframe resource is randomly selected with medium probability;

the UE selects at least two single-carrier single-subframe resources in the set S for data transmission, wherein the UE randomly selects a plurality of carriers or all carriers in the carrier medium probability of the carrier set C, and randomly selects one single-carrier single-subframe resource in the single-carrier single-subframe resources on each selected carrier medium probability;

the UE selects at least two single-carrier single-subframe resources in the set S for data transmission, wherein the UE ranks the carriers in the carrier set C according to priority or CBR, the carrier ranks are marked as carrier 0> carrier 1> … > carrier N-1, the UE randomly selects one single-carrier single-subframe resource in the single-carrier single-subframe resource set of carrier 0 at first with moderate probability, and the subframe where the selected single-carrier single-subframe resource is located is assumed to be t0; then, if the single-carrier single-subframe resource exists in the subframe t0 of the carrier 1, the UE randomly selects one single-carrier single-subframe resource from the moderate probability, if the single-carrier single-subframe resource does not exist in the subframe t0 of the carrier 1, the UE randomly selects one single-carrier single-subframe resource from the single-carrier single-subframe resource set of the carrier 1 at the moderate probability, and the like, and the UE selects the single-carrier single-subframe resource on other carriers according to the same method;

The UE selects a plurality of single-carrier single-subframe resources in the set S for data transmission, wherein the UE selects at most one single-carrier single-subframe resource on each carrier, and the variance of a subframe sequence number where the single-carrier single-subframe resource finally selected by the UE is minimum, if at least two choices with minimum variances are met, the UE randomly determines one from the intermediate probability;

the UE is in each subset S of the set S ^c The remaining single carrier single frame resources of (2) are randomly selected from X single carrier single frame resources respectively with moderate probability, and then the first UE selects from each S ^c Selecting m from the selected X single carrier single subframe resources _c A single carrier single subframe resource is used for PSSCH transmission, where c=0, 1, …, N-1, m _c Equal to 0 or 1.

Preferably, before the UE selects at least one single subframe resource in the set S, the UE further includes: the UE excludes part of candidate single subframe resources in the set S according to the bypass control channel PSCCH detected in the channel detection window and the average received energy S-RSSI of the measured resources;

the UE selects at least one single subframe resource in the set S as follows: the UE selects at least one single-carrier single-subframe resource from the rest single-carrier single-subframe resources of the set S.

Preferably, the UE excludes part of candidate monocot frame resources in the set S according to PSCCH detected in the channel detection window and S-RSSI obtained by measurement, including:

If the UE is in a sub-set of the channel detection window of carrier cFrame(s)PSCCH was detected, c=0, 1,.. and the priority field in the PSCCH has a value of prio _RX The PSCCH reserves subframes according to the resource reservation domain indicationThe same frequency resource on the PSSCH and the value of PSSCH-RSRP measured on the PSCCH scheduled PSSCH is greater than the set threshold +.>Wherein prio is _TX A value representing the priority field in the subsequently transmitted PSCCH indicated by the UE higher layer,the value of the priority field in the PSCCH representing the subsequent transmission of the higher layer indication of the UE on carrier c is prio _TX While the priority field in the detected PSCCH is prio _RX When the PSSCH-RSRP threshold is exceeded, then:

for subset S of set S ^c Any one of the single carrier single subframe resourcesIf there is a variable j e {0, 1., _resel -1} enables a single subframe resource +.>Overlap with reserved resources indicated in the PSCCH, where C _resel Representing the number of times of resource reservation after UE resource reselection, P _{rsvp_TX} A resource reservation interval assumed when determining available candidate single subframe resources, representing a UE high-level indication, the first UE will single subframe resources +.>From the set S ^c Delete in the middle;

for subset S of set S ^c Remaining monocot frame resources in (a)c=0, 1, & gt >Average of the S-RSSI measured on the sub-channel x+k, where: j is an integer greater than zero,p is a set value, which represents an S-RSSI average period, and the value of the S-RSSI is recorded as +.>The UE will aggregate S ^c In the remaining monocotyledonous frame resources->The highest 1-X% of resources are excluded, X is the set value.

dividing the carriers in the carrier set C into at least one carrier group, wherein each carrier group consists of at least one carrier, the number of the carrier groups in the carrier set C is denoted as R, the number of the carriers in the carrier set G is denoted as M, wherein G=0, 1, …, R-1, M is less than or equal to N, and M is more than or equal to 1, N is the number of the carriers in the carrier set C, and the carriers in the carrier groups are denoted as G respectively ₀ ，g ₁ ，…,g _M-1 ；

Defining a carrier group sub-frame resource in carrier group GFor being located at subframe->Upper carrier g ₀ Sub-channel->Is the starting point +.>A number of consecutive sub-channels, located in sub-frames +.>Upper carrier g ₁ Sub-channel->Is the starting point +.>A number of consecutive sub-channels …, and are located in sub-frames + ->Upper carrier g _M-1 Sub-channel->Is the starting point +.>A number of consecutive subchannels, wherein:

y represents a subframeA relative index within the resource pool;

satisfy->L is determined by the UE higher layers, i=0, 1, once again, M-1.

If the UE performs resource selection or reselection in subframe n, then [ n+T ] on carrier group G ₁ ,n+T ₂ ]The sub-frames belonging to the resource pool are respectively positioned on the carrier g in any one of the ranges ₀ ，g ₁ ，…,g _M-1 Is a continuous one of (2)The sub-channels are all candidate single subframe resources, wherein T ₁ And T ₂ Determination by UE implementation, recording that the total number of single subframe resources on wave group G is +.> The set of candidate single subframe resource components is S ^G ，…, and->Greater than or equal to zero; the union set formed by all the carrier group sub-frame resource sets in the carrier set C is the candidate sub-frame resource set S, wherein the carrier group sub-frame resource refers to at least one carrier of which the sub-channel contained in one sub-frame resource is positioned in one carrier group.

the UE only selects one carrier group single subframe resource in the set S for data transmission, wherein the UE randomly selects one carrier group single subframe resource from the set S with medium probability; alternatively, the UE selects one carrier group G at moderate probability among all carrier groups in carrier set C and selects one carrier group G at set S ^G A carrier group single subframe resource is randomly selected with medium probability;

the UE selects a plurality of carrier group sub-frame resources in the set S for data transmission, wherein the UE selects at most one carrier group sub-frame resource on each carrier group, the UE selects at least two carrier groups or all carrier groups at moderate probability in the carrier group of the carrier set C, and selects one carrier group sub-frame resource at equal probability on each selected carrier group at random.

Preferably, before the UE selects at least one single subframe resource in the set S, the UE further includes: the UE excludes part of candidate single subframe resources in the set S according to the PSCCH detected in the channel detection window and the measured S-RSSI;

the UE selects at least one single subframe resource in the set S as follows: the UE selects at least one single subframe resource from the remaining carrier group single subframe resources of the set S.

if the UE is in a subframe within the channel detection window of carrier cPSCCH was detected, c=0, 1,.. and the priority field in the PSCCH has a value of prio _RX The PSCCH reserves subframes according to the resource reservation domain indicationThe same frequency resource on the PSSCH and the value of PSSCH-RSRP measured on the PSCCH scheduled PSSCH is greater than the set threshold +.>Wherein prio is _TX A value representing the priority field in the subsequently transmitted PSCCH indicated by the UE higher layer,the value of the priority field in the PSCCH representing the subsequent transmission of the higher layer indication of the UE on carrier c is prio _TX While the priority field in the detected PSCCH is prio _RX When the PSSCH-RSRP threshold is exceeded, then:

If carrier c belongs to carrier group G, then for subset S of set S ^G Any one of the carrier group single subframe resourcesIf there is a variable j e {0,1,...,C _resel -1} is such that carrier group single subframe resource +.>Overlap with reserved resources indicated in the PSCCH, where C _resel Representing the number of times of resource reservation after UE resource reselection, P _{rsvp_TX} A resource reservation interval assumed when determining available candidate single subframe resources, representing a UE high-level indication, the UE will single subframe resources +.>From the set S ^G Delete in the middle;

for subset S of set S ^G Remaining monocot frame resources in (a)G=0, 1, …, R-1, ue calculates subframe +_within the channel detection window>Medium carrier g _i An average of the S-RSSI measured on sub-channel x+k, wherein: j is an integer greater than zero, i=0, 1, &..>P is a set value to represent the average period of the S-RSSI, and the value of the S-RSSI is recorded asThe UE will aggregate S ^G In the remaining monocotyledonous frame resources->The highest 1-X% of resources are excluded, X is the set value.

Preferably, before the UE selects at least one single subframe resource in the set S, the UE further includes: if the UE has determined that a receive operation needs to be performed on at least one subframe on at least one carrier subsequent to subframe n, the UE excludes part of the candidate single subframe resources in the set S that have a likelihood of overlapping or collision with the at least one subframe.

Preferably, the receiving operation that the UE has determined to need to perform includes:

receiving the SLSS in a subframe m of at least one carrier according to the receiving rule of the SLSS;

determining that a downlink control or data channel needs to be received in a subframe m of at least one carrier according to the downlink control or data channel receiving behavior, wherein the downlink control or data channel at least comprises one of the following:

a PDCCH indicating a random access feedback RAR and a PDSCH carrying the RAR;

physical broadcast channel PBCH;

indicating PDCCH sent by the broadcast signaling and PDSCH carrying the broadcast signaling;

PDSCH transmitted in semi-persistent scheduling SPS.

Preferably, the method further comprises:

after at least one single subframe resource is selected, the UE semi-statically occupies the selected single subframe resource for Y periods according to a set resource reservation period; in the process of semi-statically occupying the selected single subframe resource by the UE, if the size of a data packet sent by the UE is changed, so that the current single subframe resource cannot bear a new data packet even under the condition of using the allowed highest modulation order and code rate, the UE gives up the current selected single subframe resource and performs the resource selection or reselection method to reselect one single subframe resource; or the UE continues to reserve the currently selected single-subframe resource, and performs the method of selecting or reselecting the resource to additionally select one single-subframe resource on a carrier other than the carrier where the current single-subframe resource is located.

Preferably, before the PSSCH is transmitted, the method further includes:

if the UE needs to transmit signals on a plurality of carriers at a certain moment and the number of the carriers to be transmitted simultaneously is larger than the number of the radio frequency transmission links currently available for the UE, the UE should preferentially ensure the transmission of the high-priority signals and discard the transmission of the low-priority signals;

if the UE needs to transmit signals on two or more carriers at a certain moment and the UE does not support simultaneous transmission on the multiple carriers, the UE should preferentially ensure transmission of the high priority signal and discard transmission of the low priority signal;

if the UE needs to transmit signals on at least two carriers at the same time instant, the UE adjusts the transmit power, the signals including at least one of PSSCH, PSCCH and uplink signals.

Preferably, the UE adjusts the transmit power as follows:

step 1. If the value of the priority field in PSCCH transmitted by UE on at least one carrier is greater than or equal to the threshold of the priority set by the UE, the UE adjusts the bypass transmission power on the carrier with the value of the priority field greater than or equal to the threshold of the priority set by the UE so that the total transmission power of the UE is smaller than the maximum transmission power P of the UE allowed at present _CMAX ；

Step 2. If the priority field value in PSCCH of all bypass communication carriers is smaller than thresSL-TxPrioritization, or the UE adjusts the transmission power of all the carriers meeting the conditions to zero in step 1, the total transmission power is still larger than P _CMAX And the UE transmits the uplink signal on at least one carrier, the UE adjusts the transmission power of the uplink signal on the at least one carrier so that the total transmission power of the UE is smaller than the maximum transmission power P of the UE allowed at present _CMAX ；

Step 3. If the priority domain value in PSCCH of all the current bypass communication carriers of the UE is smaller than the threshold SL-TxPrioritization and the UE does not send uplink signals on any carrier, the UE adjusts the bypass signal transmission power on the carrier so that the total transmission power of the UE is smaller than the maximum transmission power P of the UE allowed at present _CMAX 。

Preferably, the UE adjusts the transmit power according to the following operations:

the UE determines the priority of the transmission signal on each carrier and adjusts the transmission power on at least one carrier with the lowest priority so that the total transmission power of the UE is smaller than the maximum transmission power P of the UE allowed at present _CMAX The method comprises the steps of carrying out a first treatment on the surface of the If it isAfter the power on the at least one carrier with the lowest priority is adjusted to zero, the total transmission power of the UE is still greater than P _CMAX The UE repeatedly performs the operation on the rest carrier until the total transmission power of the UE is smaller than the maximum transmission power P of the UE allowed at present _CMAX ；

Wherein the priority of the bypass signal is determined by the value of the priority field in the PSCCH of the bypass signal, the greater the value of the field, the lower the priority; if an uplink signal exists, the Priority of the uplink signal is higher than that of a bypass signal with a Priority domain of thresSL-txprioritisation, and the Priority of the uplink signal is lower than that of a bypass signal with a Priority domain of thresSL-txprioritisation-1, wherein the thresSL-txprioritisation represents a set Priority threshold.

The application also provides a UE for performing resource selection or reselection in V2X communication, comprising: the device comprises a candidate time-frequency resource determining module, a resource selecting or reselecting module and a sending module, wherein:

the candidate time-frequency resource determining module is used for determining at least one carrier wave for the UE to perform channel detection and determining a candidate monocotyledonous frame resource set;

the resource selection or reselection module is used for selecting one or more monocotyledonous frame resources from the candidate monocotyledonous frame resource set for data transmission;

the transmitting module is configured to transmit the PSSCH on the selected one or more single subframe resources.

Through the method and the device, the UE firstly determines a carrier set C and a candidate single-subframe resource set S in the carrier set C which can be used for resource selection or reselection, then the UE excludes part of the candidate single-subframe resources in the set S according to a channel detection result, and finally the UE selects one or more single-subframe resources from the rest single-subframe resources in the set S to send PSSCH. According to the technical scheme provided by the application, the possibility of selecting the frequency resources on the same subframe when the UE performs resource selection or reselection on a plurality of carriers is increased, so that the half-duplex limit and IBE interference existing in a multi-carrier bypass communication environment are effectively reduced, and the performance of a V2X system is improved.

Drawings

FIG. 1 is a flow chart of a resource selection or reselection method in accordance with an embodiment of the present application;

fig. 2 is a schematic diagram of a carrier group subframe resource proposed according to the present application;

fig. 3 is a block diagram of a UE performing a resource selection or reselection method in V2X communication according to an embodiment of the present application.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless expressly stated otherwise, as understood by those skilled in the art. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or wirelessly coupled. The term "and/or" as used herein includes all or any element and all combination of one or more of the associated listed items.

It will be understood by those skilled in the art that all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs unless defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As used herein, "user equipment" and "terminal equipment" are understood by those skilled in the art to include both wireless signal receiver equipment having only wireless signal receiver equipment without transmitting capabilities and receiving and transmitting hardware equipment having receiving and transmitting hardware capable of bi-directional communication over a bi-directional communication link. Such a device may include: a cellular or other communication device having a single-line display or a multi-line display or a cellular or other communication device without a multi-line display; a PCS (Personal Communications Service, personal communication system) that may combine voice, data processing, facsimile and/or data communication capabilities; a PDA (Personal Digital Assistant ) that may include a radio frequency receiver, pager, internet/intranet access, web browser, notepad, calendar and/or GNSS (Global Navigation Satellite System ) receiver; a conventional laptop and/or palmtop computer or other appliance that has and/or includes a radio frequency receiver. As used herein, "user equipment," "terminal equipment," may be portable, transportable, installed in a vehicle (aeronautical, maritime, and/or land-based), or adapted and/or configured to operate locally and/or in a distributed fashion, and/or at any other location(s) on earth and/or in space. The "user equipment" and "terminal equipment" used herein may also be communication terminals, internet surfing terminals, music/video playing terminals, for example, PDAs, MIDs (Mobile Internet Device, mobile internet devices) and/or mobile phones with music/video playing functions, and may also be devices such as smart televisions, set top boxes, etc.

Hereinafter, unless specifically stated, a first UE refers to a UE performing channel detection and resource selection or reselection, and a second UE refers to a UE detected by the first UE.

In order to increase the system capacity and data rate of V2X communication, the UE needs to use multiple bypass carriers for V2X communication. In order to solve the problems of half-duplex limitation, IBE interference and the like in multi-carrier bypass communication, the application provides a method for executing resource selection or reselection in V2X communication, which can increase the possibility of selecting frequency resources on the same subframe when UE executes resource selection or reselection on a plurality of carriers, thereby effectively reducing the half-duplex limitation and IBE interference existing in a multi-carrier bypass communication environment and improving the performance of a V2X system.

FIG. 1 is a flow chart of a resource selection or reselection method in accordance with an embodiment of the present application. The flow shown in fig. 1 includes the following steps:

in step S101, the first UE determines a carrier set C available for resource selection or reselection.

Carrier set C may include one or more carriers. The UE may be configured or preconfigured from all carrier sets C according to the current traffic type _S Is determined for the available candidate carriers. And may further determine one or more carriers available for channel selection or reselection from the candidate carriers according to the above information such as the channel congestion level (CBR) of the candidate carriers, and preferably, the first UE may select one or more carriers with the lowest CBR level from the carrier set Cs, or select one or more carriers with CBR level lower than a specific threshold in the set Cs, where the specific threshold may be defined by a standard, configured or preconfigured by the eNB. Let the number of carriers in carrier set C be N.

The UE may determine all the above-described carrier set C by receiving the systemiformationblocktype 21 or rrcconnectionreconfigurationsignaling defined in 3GPP TS 36.331V14.3.0 _S In this case, set C _S The same typeTxSync parameter may be corresponding to all carriers or each carrier may correspond to a respective typeTxSync parameter, but the values of all typeTxSync are the same. For example, C _S The carriers in (a) are divided into a plurality of carrier groups, each carrier group comprises one or more carriers, and one or more carriers in each group correspond to the same typeTxSync. The typeTxSync may be an eNB or a GNSS, which indicates that the plurality of carriers preferably use the eNB or the GNSS as a reference synchronization source. Furthermore, the UE may be preconfigured byDetermining the set C of all carriers _S In this case, set C _S The multiple carriers or all carriers in (a) may correspond to the same synchronization parameter or each carrier may correspond to a respective synchronization parameter, but all the synchronization parameters have the same value. For example, C _S The carriers in (a) are divided into a plurality of groups, each group comprises one or more carriers, and the one or more carriers in each group correspond to the same synchronization priority. The value of the synchronization priority may be eNB or GNSS, which means that the multiple carriers preferentially use the eNB or GNSS as a reference synchronization source.

According to one implementation of the present application, if one or more carriers are included in the carrier set C, the configuration of bypass synchronization signal (SLSS) transmission subframes on some or all of the carriers should be the same. For example, the transmission period of the SLSS on each carrier, the number of the SLSS subframes in each SLSS transmission period, and the relative offset of each SLSS transmission subframe in each SLSS transmission period in the carrier set C, which belong to the same frequency band, should be the same, so as to ensure that the number and the positions of the subframes available for PSCCH and PSSCH transmission on the multiple carriers are the same, and avoid overlapping of one subframe on one carrier and a subframe on another carrier or multiple carriers. Alternatively, if the carrier set C includes one or more carriers, the pre-configuration of the bypass synchronization signal (SLSS) transmission subframes on some or all of the carriers in the carrier set C should be the same, and if the subframe x is a SLSS transmission subframe according to the pre-configuration information, the subframe x cannot be used for resource pool configuration, i.e., a bitmap for resource pool configuration cannot be mapped to the subframe x.

According to another implementation of the present application, if one or more carriers are included in the carrier set C, the configuration of the bypass synchronization signal (SLSS) transmission subframes on some or all of the carriers may be different, in which case, if subframe x transmits a subframe on the SLSS on any one of the carriers, subframe x cannot be used for resource pool configuration on all of the multiple carriers, i.e., a bitmap for resource pool configuration cannot be mapped to subframe x. For example, the transmission period of the SLSS on each of the multiple inter-interference carriers in the carrier set C, the number of SLSS subframes in each SLSS transmission period, and the relative offset of each SLSS transmission subframe in each SLSS transmission period are not identical, and all the SLSS transmission subframes on the multiple inter-interference carriers cannot be used for resource pool configuration. The first UE may consider all carriers belonging to the same frequency band as mutual interference carriers, or consider multiple carriers adopting the same transmission or reception radio frequency link as mutual interference carriers, or determine multiple carriers of mutual interference according to configuration signaling or pre-configuration of the eNB. Alternatively, if one or more carriers are included in the carrier set C, the pre-configuration of the bypass synchronization signal (SLSS) transmission subframes on some or all of the carriers may be different, in which case, if the subframe x is transmitted by the SLSS on any one of the carriers according to the pre-configuration information on each carrier, the subframe x cannot be used for resource pool configuration on all of the multiple carriers, i.e., the bitmap for resource pool configuration cannot be mapped to the subframe x.

According to yet another implementation of the present application, if one or more carriers are included in carrier set C, the SLSS transmit subframe configuration and the resource pool configuration are independent of each other for each of some or all of the carriers.

Preferably, if the carrier set C includes a plurality of carriers, then on each carrier:

in step S102, the first UE determines a candidate set of monocotyledonous frame resources S in the carrier set C.

In an exemplary embodiment, the sub-channels included in the single-carrier resources are all located on the same carrier, which is referred to as a single-carrier single-subframe resource. In this case, a single-subframe resource resource is defined on any carrier C in the carrier set CFor subframe->L starting from subchannel x ^c _subCH A number of consecutive subchannels, wherein:

y represents a subframeA relative index within the resource pool;

L ^c _subCH the number of subchannels on carrier c for one PSSCH transmission, c=0, 1,...

If the UE performs resource selection or reselection in subframe n, the UE should place [ n+T ] on carrier c ₁ ,n+T ₂ ]Continuous L on any one of subframes belonging to resource pool within range ^c _subCH The sub-channels are considered as candidate single subframe resources, where T ₁ And T ₂ The decision is implemented by the UE. Recording the total number of the single subframe resources on the carrier c as The set of candidate single subframe resource components is S ^c . In this exemplary embodiment, the union set formed by the single-carrier single-subframe resource sets on each carrier in the carrier set C is the candidate single-subframe resource set S.

In another exemplary embodiment, the carriers in the carrier set C are divided into one or more carrier groups, and one carrier group is composed of one or more carriers, for example, carriers belonging to the same frequency band in the carrier set C are one carrier group. In this case, the sub-channel included in one single subframe resource may be located in a plurality of carriers in one carrier group, which is referred to as a carrier group single subframe resource. The carrier groups may be determined by eNB configuration or pre-configuration, or by a UE higher layer (e.g., UE MAC layer). Assuming that there are R carrier groups in the carrier set C, the number of carriers in the carrier group G is M, where g=0, 1, …, R-1, M is less than or equal to N, and M may be 1, and the carriers in the carrier groups are G, respectively ₀ ，g ₁ ，…,g _M-1 Defining a single subframe resource of a carrier group in the carrier group GFor being located at subframe->Upper carrier g ₀ Sub-channel->Is the starting point +.>A number of consecutive sub-channels, located in sub-frames +. >Upper carrier g ₁ Sub-channel->Is the starting point +.>A number of consecutive sub-channels …, and are located in sub-frames + ->Upper carrier g _M-1 Sub-channel->Is the starting point +.>Successive sub-channels are shown in figure 2. Wherein:

y represents a subframeA relative index within the resource pool;

is determined by the UE physical layer and satisfies +.>L is determined by the UE higher layers (e.g. MAC layer), i=0, 1, &.. M-1; or (F)>Determined by higher layers of the UE, e.g., by the MAC layer of the UE. It should be noted that in particular it is possible,and->May be zero.

If the UE performs resource selection or reselection in subframe n, the UE should place [ n+T ] on carrier group G ₁ ,n+T ₂ ]The sub-frames belonging to the resource pool are respectively positioned on the carrier g in any one of the ranges ₀ ，g ₁ ，…,g _M-1 Is a continuous one of (2) The sub-channels are considered as candidate single subframe resources, where T ₁ And T ₂ The decision is implemented by the UE. Recording the total number of the single subframe resources on the wave group G as The set of candidate single subframe resource components is S ^G . In this exemplary embodiment, the union set formed by all the carrier group sub-frame resource sets in the carrier set C is the candidate sub-frame resource set S.

Step S103, the first UE excludes part of the candidate monocotyledonous frame resources in the set S.

It should be noted that this step is an optional step, and if this step is not performed, candidate single subframes in the set S are not selected The resource is excluded, and accordingly, in subsequent processing, in the set S, S ^c 、S ^G Is adapted to be at set S, S for operations performed in the remaining monocot frame resources of (c) ^c 、S ^G And is executed.

Suppose that the UE performs resource selection in subframe n.

First, the UE may determine that it is necessary to exclude part of the candidate single subframe resources from the set S based on the determined reception operation on future subframes. That is, if the UE has determined that a receive operation needs to be performed on one or more subframes on some one or more carriers after subframe n, the UE may exclude some candidate single subframe resources in set S that may overlap or collide with the one or more subframes. Specifically, without loss of generality, assuming that the UE has determined that subframe m following subframe n of carrier C performs a receive operation, for any subframe y in set S for which there is a subframe resource, if there is a variable j e {0,1, C.) _resel -1 to enable the single subframe resource y+j×p _{rsvp_TX} And sub-frame m overlap, where C _resel Representing the number of times of resource reservation after UE resource reselection, P _{rsvp_TX} The resource reservation interval assumed when the UE high-level indication determines available candidate single subframe resources is indicated, and the first UE excludes all single subframe resources on the subframe y of all carriers interfering with the carrier c in the set S. The first UE may consider all carriers belonging to the same frequency band as the carrier c to interfere with the carrier c, or consider carriers adopting the same transmission or reception radio frequency link as the carrier c to interfere with the carrier c, or determine the carrier interfering with the carrier c according to the configuration signaling or the pre-configuration of the eNB. The reception operations that the UE has determined to need to perform include, but are not limited to: receiving the SLSS in a subframe m of one or more carriers according to the receiving rule of the SLSS; determining that a downlink control or data channel needs to be received in a subframe m of one or more carriers according to the downlink control or data channel receiving behavior, wherein the downlink control or data channel at least comprises one of the following:

PDCCH indicating RAR (random access feedback, random Access Response) and PDSCH carrying RAR;

physical Broadcast Channel (PBCH);

PDSCH transmitted in semi-persistent scheduling SPS.

In addition, the first UE may exclude a part of the candidate monocot frame resources in the candidate monocot frame set S only according to the PSCCH detected in the channel detection window and the measured S-RSSI.

If the UE performs resource selection on subframe n, the UE may detect subframes within a channel detection window preceding subframe n on each carrier of carrier set C, where the channel detection window is defined by a standard, e.g., defining subframes n-1000, n-999, …, n-1 as channel detection windows. For subframes detected by the first UE, the first UE should measure PSSCH-RSRP on the subframes and measure S-RSSI on the subframes from the decoded PSCCH.

The first UE excludes the candidate monocot frame resources in set S according to the following two steps.

Candidate single subframe resource exclusion step 1:

if the first UE is in a subframe within the channel detection window of carrier cPSCCH was detected, c=0, 1,.. and the Priority field (Priority) value prio in the PSCCH _RX The PSCCH reserves sub-frames according to the resource reservation field (Resource reservation) indication >The same frequency resource on the PSSCH and the value of PSSCH-RSRP measured on the PSCCH scheduled PSSCH is greater than a certain threshold +.>Wherein prio is _TX A value representing the priority field in the subsequently transmitted PSCCH indicated by the first UE higher layer,/-, for example>Configured or preconfigured by eNB, representingThe value of the priority field in the subsequently transmitted PSCCH indicated by the first UE higher layer on carrier c is prio _TX While the priority field in the detected PSCCH is prio _RX At this time, PSSCH-RSRP threshold. Then:

if set S is a single carrier single subframe resource set, then for subset S of set S ^c Any one of the single carrier single subframe resourcesIf there is a variable j e {0, 1., _resel -1} enables a single subframe resource +.>Overlap with reserved resources indicated in the PSCCH, where C _resel Representing the number of times of resource reservation after UE resource reselection, P _{rsvp_TX} A resource reservation interval assumed when determining available candidate single subframe resources, representing a UE high-level indication, the first UE selecting or reselecting resources with single subframe resources +.>Exclusion, namely: the first UE is to add the single subframe resource>From the set S ^c And deleted.

If the set S is a carrier group single subframe resource set and the carrier c belongs to the carrier group G, then for a subset S of the set S ^G Any one of the carrier group single subframe resources If there is a variable j e {0, 1., _resel -1} is such that carrier group single subframe resource +.>Overlap with reserved resources indicated in the PSCCH, where C _resel Representing the number of times of resource reservation after UE resource reselection, P _{rsvp_TX} Determination of indicating UE high level indicationResource reservation interval assumed when candidate single subframe resources are available, the first UE selects or reselects the single subframe resources>Exclusion, namely: the first UE uses the single subframe resourceFrom the set S ^G And deleted.

Candidate single subframe resource exclusion step 2:

if set S is a single carrier single subframe resource set, then for subset S of set S ^c Remaining monocot frame resources in (a)c=0, 1, & gt>Average of the S-RSSI measured on the sub-channel x+k, where: j is an integer greater than zero, +.>P is a specific value, defined by a standard, configured by an eNB or preconfigured, representing an S-RSSI averaging period, e.g., p=100 or a resource reservation interval assumed when determining available candidate single subframe resources as indicated by a UE higher layer; the S-RSSI value is +.>The first UE will aggregate S ^c In the remaining monocotyledonous frame resources->The highest 1-X% resource exclusion, X is a specific value defined by the standard or determined by the first UE according to eNB configuration, pre-configuration, or current traffic type, etc.

If set S is a carrier group single subframe resource set, then for subset S of set S ^G Residue in (a)Residual sub-frame resourcesG=0, 1, …, R-1, the first UE calculates subframe +_within the channel detection window>Medium carrier g _i An average of the S-RSSI measured on sub-channel x+k, wherein: j is an integer greater than zero, i=0, 1, &..>P is a specific value, defined by a standard, configured by an eNB or preconfigured, representing an S-RSSI averaging period, e.g., p=100 or a resource reservation interval assumed when determining available candidate single subframe resources as indicated by a UE higher layer; the S-RSSI value is +.>The first UE will aggregate S ^G In the remaining monocotyledonous frame resources->The highest 1-X% resource exclusion, X is a specific value defined by the standard or determined by the first UE according to eNB configuration, pre-configuration, or current traffic type, etc.

Step S104, the first UE selects one or more single-subframe resources from the rest single-subframe resources of the set S, and sends PSSCH on the selected resources.

If the set S is a single-carrier single-subframe resource, i.e. a carrier group is not configured, according to an implementation manner of the present application, the first UE may select only one single-carrier single-subframe resource from the remaining single-carrier single-subframe resources of the set S for data transmission. At this time, the first UE may randomly select a single-carrier single-subframe resource from the remaining single-carrier single-subframe resources in the set S with moderate probability; alternatively, the first UE may choose one carrier C at moderate probability among all carriers in the carrier set C, and then at set S ^c Is randomly selected with moderate probability by the rest single carrier single frame resourceSingle carrier single subframe resources.

If the set S is a single-carrier single-subframe resource, i.e. a carrier group is not configured, according to another implementation method of the present application, the first UE may select a plurality of single-carrier single-subframe resources from the remaining single-carrier single-subframe resources of the set S for data transmission. At this time, the first UE may randomly select a plurality of carriers or select all carriers at a medium probability among the carriers of the carrier set C, and randomly select one single-carrier single-subframe resource at a medium probability among the remaining single-carrier single-subframe resources on each selected carrier.

If the set S is a single-carrier single-subframe resource, i.e. a carrier group is not configured, according to a further implementation method of the present application, the first UE may select a plurality of single-carrier single-subframe resources from the remaining single-carrier single-subframe resources of the set S for data transmission. At this time, the first UE ranks the carriers in the carrier set C according to priority or CBR, assuming that the carrier ranks as carrier 0> carrier 1> … > carrier N-1. Then, the first UE randomly selects a single-carrier single-subframe resource in the rest single-carrier single-subframe resource set of the carrier 0 at moderate probability, and presumes that the subframe where the selected single-carrier single-subframe resource is positioned is t0; then, if there is a remaining single-carrier single-subframe resource at sub-frame t0 of carrier 1, the first UE randomly selects one single-carrier single-subframe resource from the intermediate probability, and if there is no remaining single-carrier single-subframe resource at sub-frame t0 of carrier 1, the first UE randomly selects one single-carrier single-subframe resource at the intermediate probability in the remaining single-carrier single-subframe resource set of carrier 1, assuming that the single-carrier single-subframe resource selected on carrier 1 is t1; thereafter, the first UE selects single carrier single frame resources on the other carriers in the same way.

If the set S is a single-carrier single-subframe resource, i.e. a carrier group is not configured, according to a further implementation method of the present application, the first UE may select a plurality of single-carrier single-subframe resources from the remaining single-carrier single-subframe resources of the set S for data transmission. At this time, the first UE selects at most one single-carrier single-subframe resource on each carrier, and the variance of the subframe sequence number where the single-carrier single-subframe resource finally selected by the first UE is smallest, if a plurality of choices with smallest variances are satisfied, the first UE may randomly determine one from the intermediate probabilities as the final choice.

If the set S is a single carrier single subframe resource, i.e. a carrier group is not configured, according to a further implementation of the application, the first UE is in each subset S of the set S ^c The remaining single carrier single frame resources of (2) are randomly selected from X single carrier single frame resources respectively with moderate probability, and then the first UE selects from each S ^c Selecting m from the selected X single carrier single subframe resources _c A single carrier single subframe resource is used for PSSCH transmission, where c=0, 1, …, N-1, m _c Equal to 0 or 1.

If the set S is a carrier group subframe resource, i.e. a carrier group is configured, according to an implementation manner of the present application, the first UE may select only one carrier group subframe resource from the remaining carrier group subframe resources of the set S for data transmission. At this time, the first UE may randomly select one carrier group subframe resource from the remaining carrier group subframe resources in the set S with moderate probability; alternatively, the first UE may randomly select one carrier group G with moderate probability among all carrier groups in the carrier set C, and then select the carrier group G in the set S ^G A carrier group sub-frame resource is randomly selected with a medium probability.

If the set S is a carrier group subframe resource, i.e. a carrier group is configured, according to another implementation method of the present application, the first UE may select a plurality of carrier group subframe resources from the remaining carrier group subframe resources of the set S for data transmission. At this time, the first UE selects at most one carrier group sub-frame resource on each carrier group, and the UE may randomly select a plurality of carrier groups or all carrier groups with moderate probability in the carrier groups of the carrier set C, and randomly select one carrier group sub-frame resource with moderate probability in the remaining carrier group sub-frame resources on each selected carrier group.

It should be noted that, after the above resource selection process is performed, the first UE semi-statically occupies the selected subframe resource for Y periods according to a certain resource reservation period, where Y is randomly determined by the UE higher layer within a certain range, for example, is randomly determined by the MAC layer of the UE with equal probability within a range of 5-15. In the process that the first UE semi-statically occupies the selected single subframe resource, if the size of a data packet sent by the UE is changed, the current single subframe resource cannot bear a new data packet even under the condition that the allowable highest modulation order and code rate are used. In this case, it is preferable that the first UE discard the currently selected one, and then perform steps S101 to S104 to reselect one; alternatively, the first UE may continue to reserve the currently selected subframe resource, and then perform steps S101 to S104 to additionally select one subframe resource on a carrier other than the carrier on which the currently selected subframe resource is located.

In order to facilitate understanding of the present application, the following further describes the above technical solution of the present application in a mode of interaction between devices in combination with specific application cases, which is specifically as follows:

example 1

In the first embodiment, the plurality of carriers for the first UE to perform channel detection and resource selection are one carrier group, that is, the single subframe resource is a single subframe resource of the carrier group. The specific steps of this embodiment are as follows:

in step S201, the first UE determines a carrier set C available for resource selection or reselection.

In this embodiment, the carrier set C includes a plurality of carriers, and all the carriers in the carrier set C belong to the same carrier group. Assuming that the number of carriers in the carrier set C is N, the number and the positions of the SLSS transmission subframes on each carrier in the N carriers are identical; or if the configurations of the SLSS transmission subframes on the N carriers are different, all the SLSS transmission subframes on the N carriers are not used for resource pool configuration.

In step S202, the first UE determines a candidate set of monocotyledonous frame resources S in the carrier set C.

In this embodiment, assuming that the UE performs resource selection or reselection in subframe n, the carrier group consisting of carriers in the carrier set C is G, and the number of carriers included in the carrier group G is M, the UE shall perform [ n+t ] on the carrier group G ₁ ,n+T ₂ ]Any one of subframes belonging to the resource pool in the range respectivelyLocated at carrier g ₀ ，g ₁ ，…,g _M-1 Is a continuous one of (2) The sub-channels are considered as candidate single subframe resources, where T ₁ And T ₂ The decision is implemented by the UE. Recording the total number of the single subframe resources on the wave group G as The set of candidate single subframe resource components is S ^G . It should be noted that->And->May be zero. Set S ^G I.e. set S.

In step S203, the first UE excludes part of the candidate single subframe resources in the set S according to the channel detection result.

Assuming that the UE performs resource selection at subframe n, the UE may detect subframes within a channel detection window preceding subframe n on each carrier of carrier set C, where the channel detection window is defined by a standard, e.g., defining subframes n-1000, n-999, …, n-1 as channel detection windows. For subframes detected by the first UE, the first UE should measure PSSCH-RSRP on the subframes and measure S-RSSI on the subframes from the decoded PSCCH.

In the present embodiment, the candidate single subframe resource exclusion step 1 is performed in the following manner:

if the first UE is in a subframe within the channel detection window of carrier cPSCCH was detected, c=0, 1,.. and the Priority field (Priority) value prio in the PSCCH _RX The PSCCH reserves sub-frames according to the resource reservation field (Resource reservation) indication>The same frequency resource on the PSSCH and the value of PSSCH-RSRP measured on the PSCCH scheduled PSSCH is greater than a certain threshold +.>Wherein prio is _TX A value representing the priority field in the subsequently transmitted PSCCH indicated by the first UE higher layer,/-, for example>Configured or preconfigured by the eNB, the value of the priority field in the PSCCH indicating the subsequent transmission indicated by the first UE higher layer on carrier c is prio _TX While the priority field in the detected PSCCH is prio _RX At this time, PSSCH-RSRP threshold. Then:

for set S (i.e. set S ^G ) Any one of the carrier group single subframe resourcesIf there is a variable j e {0, 1., _resel -1} is such that carrier group single subframe resource +.>Overlap with reserved resources indicated in the PSCCH, where C _resel Representing the number of times of resource reservation after UE resource reselection, P _{rsvp_TX} A resource reservation interval assumed when determining available candidate single subframe resources, representing a UE high-level indication, is determined by the first UE to be single subframe resources +.>From the set S ^G And deleted.

In the present embodiment, the candidate single subframe resource exclusion step 2 is performed in the following manner:

for set S (i.e. S ^G ) Remaining monocot frame resources in (a)G=0, 1, …, R-1, the first UE calculates subframe +_within the channel detection window >Medium carrier g _i Where j is an integer greater than zero, i=0, 1, &..the average of the S-RSSI measured on subchannel x+k, M-1, & gt>P is a specific value, defined by a standard, configured by an eNB or preconfigured, representing an S-RSSI averaging period, e.g., p=100 or a resource reservation interval assumed when determining available candidate single subframe resources as indicated by a UE higher layer; the S-RSSI value is +.>The first UE will aggregate S ^G In the remaining monocotyledonous frame resources->The highest 1-X% resource exclusion, X is a specific value defined by the standard or determined by the first UE according to eNB configuration, pre-configuration, or current traffic type, etc.

In step S204, the first UE selects one or more of the remaining monocot frame resources of the set S, and transmits the PSSCH on the selected resources.

In this embodiment, the first UE may randomly select one carrier group sub-frame resource at a moderate probability among the remaining carrier group sub-frame resources of the set S, and send the PSSCH with the selected carrier group sub-frame resource.

If the UE needs to transmit signals on multiple carriers at a certain time, the signals including PSSCH, PSCCH and uplink signals, according to an implementation of the present application, the UE adjusts the transmit power in the following order:

Step 1. If the UE is in oneOr the value of the "Priority" field in the PSCCH transmitted on multiple carriers is greater than or equal to the threshold, which means that the V2X data carried in the PSCCH transmitted on the one or more carriers is lower in Priority than the threshold, where the threshold represents a specific Priority threshold that is configured or preconfigured by the eNB, the UE should adjust the bypass transmit power on one or more carriers of the "Priority" field to be greater than or equal to the threshold such that the total transmit power of the UE is less than the maximum transmit power P of the currently allowed UE _CMAX ；

Step 2. If the value of the "Priority" field in PSCCH on all bypass communication carriers is smaller than thresSL-TxPrioritization, or the UE adjusts the transmission power on all the carriers meeting the conditions to zero in step 1, the total transmission power is still larger than P _CMAX And the UE transmits the uplink signals on one or more carriers, the UE adjusts the transmission power of the uplink signals on the one or more carriers so that the total transmission power of the UE is smaller than the maximum transmission power P of the UE allowed at present _CMAX ；

Step 3. If the value of the "Priority" field in PSCCH on all the current bypass communication carriers of the UE is smaller than the threshold SL-TxPrioritization and the UE does not transmit uplink signals on any carrier, the UE adjusts the bypass signal transmission power on the carrier so that the total transmission power of the UE is smaller than the maximum transmission power P of the UE allowed at present _CMAX 。

If the UE needs to transmit signals on multiple carriers at a certain time, according to another implementation of the present application, the UE adjusts the transmit power according to operation 2041: the UE determines the priority of the transmission signal on each carrier and then adjusts the transmission power on the carrier or carriers with the lowest priority of the transmission data so that the total transmission power of the UE is less than the maximum transmission power P of the currently allowed UE _CMAX . If the power on the carrier is adjusted to zero, the total transmit power of the UE is still greater than P _CMAX The UE repeatedly performs operation 2041 on the remaining carriers until the total transmit power of the UE is less than the maximum currently allowed UETransmission power P _CMAX . The Priority of a bypass signal is determined by the value of the "Priority" field in the PSCCH of the bypass signal, the greater the value of the field, the lower the Priority; if an uplink signal is present, the Priority of the uplink signal is higher than the bypass signal with the value of the "Priority" field being thresh-txpriority, and the value of the bypass signal with the value of the "Priority" field being thresh-txpriority-1, wherein thresh-txpriority represents a specific Priority threshold, which is configured or preconfigured by the eNB, and "thresh-txpriority-1" represents thresh-txpriority minus 1.

If the UE needs to transmit signals on multiple carriers at a certain moment, where the signals include PSSCH, PSCCH and uplink signals, and if the number of carriers that need to be simultaneously transmitted is greater than the number of radio frequency transmission links currently available to the UE, the UE should preferentially ensure transmission of high priority signals, and discard transmission of low priority signals. If the UE needs to transmit signals on two or more carriers at a certain moment, where the signals include PSSCH, PSCCH and uplink signals, and the UE does not support simultaneous transmission on the multiple carriers, the UE should preferentially ensure transmission of the high priority signal and discard transmission of the low priority signal. Wherein the Priority of the bypass signal is determined by the value of the "Priority" field in the PSCCH of the bypass signal, the greater the value of the field, the lower the Priority; if an uplink signal is present, the Priority of the uplink signal is higher than the bypass signal with the value of the "Priority" field being thresh-txpriority, and the value of the bypass signal with the value of the "Priority" field being thresh-txpriority-1, wherein thresh-txpriority represents a specific Priority threshold, which is configured or preconfigured by the eNB, and "thresh-txpriority-1" represents thresh-txpriority minus 1.

Example two

In the second embodiment, the plurality of carriers for the first UE to perform channel detection and resource selection are a plurality of carrier groups, for example, one or more carriers belonging to the same frequency band in the carrier set C belong to the same carrier group. At this time, the single subframe resource is a carrier group single subframe resource. The specific steps of this embodiment are as follows:

in step S301, the first UE determines a carrier set C available for resource selection or reselection.

In the present embodiment, the carrier set C includes a plurality of carriers, and the carriers in the carrier set C are divided into a plurality of carrier groups. Assuming that the number of carriers in the carrier set C is N, the N carriers are divided into R carrier groups, and the number and the positions of SLSS sending subframes on the carriers in each carrier group are identical; or, the configuration of the SLSS transmission subframes on the carriers in each carrier group is different, but all the SLSS transmission subframes on the carriers in the carrier group are not used for resource pool configuration.

In step S302, the first UE determines a candidate set of monocotyledonous frame resources S in the carrier set C.

In this embodiment, assuming that the UE performs resource selection or reselection in subframe n, for any one carrier group G in the carrier set C, the UE shall perform [ n+t ] on the carrier group G ₁ ,n+T ₂ ]The sub-frames belonging to the resource pool are respectively positioned on the carrier g in any one of the ranges ₀ ，g ₁ ，…,g _M-1 Is a continuous one of (2)The sub-channels are considered as candidate single subframe resources, where T ₁ And T ₂ The decision is implemented by the UE. Recording the total number of the single subframe resources on the wave group G as +.> The set of candidate single subframe resource components is S ^G . It should be noted that->And->Determined by higher layers of the UE, e.g., by the MAC layer of the UE, one or more of which may be zero. Instant S of all carrier groups ^G The aggregate set is the setAnd S, combining.

In step S303, the first UE excludes part of the candidate monocotyledonous frame resources in the set S according to the channel detection result.

if carrier c belongs to carrier group G, for a set of subframes S of carrier group G ^G Any one of the carrier groups of the single subframe resourceSource(s)If there is a variable j e {0, 1., _resel -1} is such that carrier group single subframe resource +.>Overlap with reserved resources indicated in the PSCCH, where C _resel Representing the number of times of resource reservation after UE resource reselection, P _{rsvp_TX} A resource reservation interval assumed when determining available candidate single subframe resources, representing a UE high-level indication, the first UE to select the single subframe resourcesFrom the set S ^G And deleted.

for set S ^G Remaining monocot frame resources in (a) G=0, 1, …, R-1, the first UE calculates subframe +_within the channel detection window>Medium carrier g _i Where j is an integer greater than zero, i=0, 1, &..the average of the S-RSSI measured on subchannel x+k, M-1, & gt>P is a specific value, defined by a standard, configured by an eNB or preconfigured, representing an S-RSSI averaging period, e.g., p=100 or a resource reservation interval assumed when determining available candidate single subframe resources as indicated by a UE higher layer; the S-RSSI value is +.>The first UE will aggregate S ^G In the remaining monocotyledonous frame resources->The highest 1-X% resource exclusion, X is a specific value defined by the standard or determined by the first UE according to eNB configuration, pre-configuration, or current traffic type, etc.

In step S304, the first UE selects one or more sub-frame resources from the remaining sub-frame resources of the set S, and transmits the PSSCH on the selected resources.

In this embodiment, the first UE is in carrier group subframe set S of R carrier groups in carrier set C ^G Randomly selects one carrier group sub-frame resource from the rest resources of the carrier group sub-frame resource for PSSCH transmission, and G=0, 1, … and R-1. First UE at S ^G The way in which the resources are randomly selected among the remaining monocot resources should ensure that the probability of each remaining monocot resource being selected is equal.

step 1. If the value of the "Priority" field in the PSCCH transmitted by the UE on one or more carriers is greater than or equal to the threshold value of the "Priority" field, which means that the Priority of V2X data carried in the PSSCH transmitted by the UE on the one or more carriers is lower than the threshold value of the Priority, which represents a specific Priority threshold, which is configured or preconfigured by the eNB, the UE should adjust the bypass transmit power on the one or more carriers of the "Priority" field to be greater than or equal to the threshold value of the threshold such that the total transmit power of the UE is less than the maximum transmit power P of the UE that is currently allowed _CMAX ；

Step 2. If the value of the "Priority" field in PSCCH on all bypass communication carriers is smaller than thresSL-TxPrioritization, or the UE adjusts the transmission power on all the carriers meeting the conditions to zero in step 1, the total transmission power is still larger than P _CMAX And the UE transmits the uplink signals on one or more carriers, the UE adjusts the transmission of the uplink signals on the one or more carriers Transmitting power such that the total transmit power of the UE is less than the maximum transmit power P of the currently allowed UE _CMAX ；

If the UE needs to transmit signals on multiple carriers at a certain time, according to another implementation of the present application, the UE adjusts the transmit power according to operation 2041: the UE determines the priority of the transmission signal on each carrier and then adjusts the transmission power on the carrier or carriers with the lowest priority of the transmission data so that the total transmission power of the UE is less than the maximum transmission power P of the currently allowed UE _CMAX . If the power on the carrier is adjusted to zero, the total transmit power of the UE is still greater than P _CMAX The UE repeatedly performs operation 2041 on the remaining carriers until the total transmit power of the UE is less than the maximum transmit power P of the currently allowed UE _CMAX . The Priority of a bypass signal is determined by the value of the "Priority" field in the PSCCH of the bypass signal, the greater the value of the field, the lower the Priority; if an uplink signal is present, the Priority of the uplink signal is higher than the bypass signal with the value of the "Priority" field being thresh-txpriority, and the value of the bypass signal with the value of the "Priority" field being thresh-txpriority-1, wherein thresh-txpriority represents a specific Priority threshold, which is configured or preconfigured by the eNB, and "thresh-txpriority-1" represents thresh-txpriority minus 1.

Example III

In the third embodiment, the carrier set C for performing channel detection and resource selection by the first UE is not configured with a carrier group, i.e., the single-carrier single-subframe resource is a single-carrier single-subframe resource. The specific steps of this embodiment are as follows:

in step S401, the first UE determines a carrier set C available for resource selection or reselection.

In this embodiment, the carrier set C includes a plurality of carriers, and the number of carriers in the carrier set C is assumed to be N. Preferably, the data and the positions of the sub-frames sent by the SLSS on each carrier in the carrier set C are the same; or, the configuration of the SLSS transmission subframes on each carrier in the carrier set C is different, but all the SLSS transmission subframes on the N carriers are not used for resource pool configuration.

In step S402, the first UE determines a candidate set of monocot frame resources S in the carrier set C.

In this embodiment, a single-subframe resource resource is defined on any carrier C in the carrier set CFor subframe->L starting from subchannel x ^c _subCH Each successive letterLane, wherein y represents subframe ++>Relative index, L, within resource pool ^c _subCH The number of subchannels on carrier c for one PSSCH transmission, c=0, 1,... If the UE performs resource selection or reselection in subframe n, the UE should place [ n+T ] on carrier c ₁ ,n+T ₂ ]Continuous L on any one of subframes belonging to resource pool within range ^c _subCH The sub-channels are considered as candidate single subframe resources, where T ₁ And T ₂ The decision is implemented by the UE. Recording the total number of the single subframe resources on the carrier c as +.> The set of candidate single subframe resource components is S ^c . And a union set formed by the single-carrier single-subframe resource sets on each carrier in the carrier set C is set S.

In step S403, the first UE excludes part of the candidate single subframe resources in the set S according to the channel detection result.

if the first UE is in a subframe within the channel detection window of carrier cPSCCH was detected, c=0, 1,.. and the value pr of the Priority field (Priority) in the PSCCHio _RX The PSCCH reserves sub-frames according to the resource reservation field (Resource reservation) indication >The same frequency resource on the PSSCH and the value of PSSCH-RSRP measured on the PSCCH scheduled PSSCH is greater than a certain threshold +.>Wherein prio is _TX A value representing the priority field in the subsequently transmitted PSCCH indicated by the first UE higher layer,/-, for example>Configured or preconfigured by the eNB, the value of the priority field in the PSCCH indicating the subsequent transmission indicated by the first UE higher layer on carrier c is prio _TX While the priority field in the detected PSCCH is prio _RX At this time, PSSCH-RSRP threshold. Then:

for subset S of set S ^c Any one of the single carrier single subframe resourcesIf there is a variable j e {0, 1., _resel -1} enables a single subframe resource +.>Overlap with reserved resources indicated in the PSCCH, where C _resel Representing the number of times of resource reservation after UE resource reselection, P _{rsvp_TX} A resource reservation interval assumed when determining available candidate single subframe resources, representing a UE high-level indication, the first UE selecting or reselecting resources with single subframe resources +.>Exclusion, namely: the first UE will have a single subframe resource +.>From the set S ^c And deleted. />

for subset S of set S ^c Remaining monocot frame resources in (a)c=0, 1, & gt >Average of the S-RSSI measured on the sub-channel x+k, where: j is an integer greater than zero,p is a specific value, defined by a standard, configured by an eNB or preconfigured, representing an S-RSSI averaging period, e.g., p=100 or a resource reservation interval assumed when determining available candidate single subframe resources as indicated by a UE higher layer; the S-RSSI value is +.>The first UE will aggregate S ^c In the remaining monocotyledonous frame resources->The highest 1-X% resource exclusion, X is a specific value defined by the standard or determined by the first UE according to eNB configuration, pre-configuration, or current traffic type, etc.

In step S404, the first UE selects one or more monocot frame resources from the remaining monocot frame resources of the set S, and transmits the PSSCH on the selected resources.

In this embodiment, the first UE selects a plurality of monocot frame resources from the remaining monocot frame resources in the set S for PSSCH transmission, where the first UE may select the plurality of monocot frame resources in one of the following manners:

mode one: the UE randomly selects a plurality of carriers or all carriers in the carrier medium probability of the carrier set C, and randomly selects a single-carrier single-subframe resource in the medium probability of the rest single-carrier single-subframe resources on each selected carrier.

Mode two: the first UE ranks the carriers in carrier set C by priority or CBR assuming carrier rank of carrier 0> carrier 1> … > carrier N-1. Then, the first UE randomly selects a single-carrier single-subframe resource in the rest single-carrier single-subframe resource set of the carrier 0 at moderate probability, and presumes that the subframe where the selected single-carrier single-subframe resource is positioned is t0; then, if there is a remaining single-carrier single-subframe resource at sub-frame t0 of carrier 1, the first UE randomly selects one single-carrier single-subframe resource from the intermediate probability, and if there is no remaining single-carrier single-subframe resource at sub-frame t0 of carrier 1, the first UE randomly selects one single-carrier single-subframe resource at the intermediate probability in the remaining single-carrier single-subframe resource set of carrier 1, assuming that the single-carrier single-subframe resource selected on carrier 1 is t1; thereafter, the first UE selects single carrier single frame resources on the other carriers in the same way.

Mode three: the first UE selects at most one single-carrier single-subframe resource on each carrier, and the variance of the subframe sequence number where the single-carrier single-subframe resource finally selected by the first UE is minimum.

Mode four: the first UE is in each subset S of the set S ^c The remaining single carrier single frame resources of (2) are randomly selected from X single carrier single frame resources respectively with moderate probability, and then the first UE selects from each S ^c Selecting m from the selected X single carrier single subframe resources _c A single carrier single subframe resource is used for PSSCH transmission, where c=0, 1, …, N-1, m _c Equal to 0 or 1, i.e. the UE can select at most one single carrier single-subframe resource or not on a carrier,the value of X may be directly configured, preconfigured, or defined by a standard, or the value of X may be indirectly configured, preconfigured, or defined by a standard, e.g.)>Wherein R is _S Is the total number of resources in set S. How to be on carrier C _i Selecting m from X single carrier single subframe resources _i The method for selecting the M single-carrier single-subframe resources by the first UE can ensure that the radio frequency transmission capability of the first UE can support PSSCH transmission on the M single-carrier single-subframe resources, and on the premise that the method for selecting the M single-carrier single-subframe resources by the first UE can minimize half-duplex restriction among the single-carrier single-subframe resources.

Step 3. If the UE currently bypasses the value of the "Priority" field in the PSCCH on all communication carriers All are smaller than thresSL-txpower and the UE does not transmit uplink signals on any carrier, the UE adjusts the bypass signal transmit power on the carrier so that the total transmit power of the UE is smaller than the maximum transmit power P of the UE allowed at present _CMAX 。

Fig. 3 is a block diagram of a User Equipment (UE) performing a resource selection or reselection method in vehicle-to-outside V2X communication according to an embodiment of the present invention. Referring to fig. 3, the apparatus includes: a candidate time-frequency resource determination module 30, a resource selection or reselection module 32, and a transmission module 33.

The candidate time-frequency resource determining module is used for determining one or more carriers for the UE to perform channel detection, and determining the number of carrier groups and the carriers contained in each carrier group under the condition that carrier group configuration exists; further, a set of candidate monocot frame resources for determining on each carrier or group of carriers;

the transmission module is configured to transmit the PSSCH on the selected one or more single subframe resources.

Preferably, the apparatus shown in fig. 3 may further include a resource detection module 31, where the resource detection module is configured to exclude a part of the candidate monocot frame resources in the candidate monocot frame set according to the PSCCH detected in the channel detection window and the measured S-RSSI, or to exclude a part of the candidate monocot frame resources in the candidate monocot frame set by another method described in step S301. In this case, the resource selection or reselection module is configured to select one or more of the remaining monocot frame resources for data transmission after the channel detection module performs an exclusion operation on the monocot frame resources in the candidate monocot frame set.

Those skilled in the art will appreciate that the present application includes apparatuses related to performing one or more of the operations described herein. These devices may be specially designed and constructed for the required purposes, or may comprise known devices in general purpose computers. These devices have computer programs stored therein that are selectively activated or reconfigured. Such a computer program may be stored in a device (e.g., a computer) readable medium or any type of medium suitable for storing electronic instructions and respectively coupled to a bus, including, but not limited to, any type of disk (including floppy disks, hard disks, optical disks, CD-ROMs, and magneto-optical disks), ROMs (Read-Only memories), RAMs (Random Access Memory, random access memories), EPROMs (Erasable Programmable Read-Only memories), EEPROMs (Electrically Erasable Programmable Read-Only memories), flash memories, magnetic cards, or optical cards. That is, a readable medium includes any medium that stores or transmits information in a form readable by a device (e.g., a computer).

It will be understood by those within the art that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions. Those skilled in the art will appreciate that the computer program instructions can be implemented in a processor of a general purpose computer, special purpose computer, or other programmable data processing method, such that the blocks of the block diagrams and/or flowchart illustration are implemented by the processor of the computer or other programmable data processing method.

Those of skill in the art will appreciate that the various operations, methods, steps in the flow, acts, schemes, and alternatives discussed in the present invention may be alternated, altered, combined, or eliminated. Further, other steps, means, or steps in a process having various operations, methods, or procedures discussed herein may be alternated, altered, rearranged, disassembled, combined, or eliminated. Further, steps, measures, schemes in the prior art with various operations, methods, flows disclosed in the present invention may also be alternated, altered, rearranged, decomposed, combined, or deleted.

The foregoing is only a partial embodiment of the present invention, and it should be noted that it will be apparent to those skilled in the art that modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the present invention.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising:

in the case where the bypass signals on the plurality of carriers overlap and the total transmit power of the overlapping bypass signals on the plurality of carriers exceeds a maximum transmit power threshold, adjusting the transmit power of the bypass signal corresponding to the lowest priority in the overlapping bypass signals so that the adjusted total transmit power of the overlapping bypass signals does not exceed the maximum transmit power threshold; and

and transmitting at least one of the overlapping bypass signals based on the adjusted transmit power of the overlapping bypass signals.

2. The method of claim 1, wherein transmissions of bypass signals on the plurality of carriers overlap in time.

3. The method of claim 2, further comprising:

after the transmission power of the bypass signal corresponding to the lowest priority among the overlapped bypass signals is adjusted, if the adjusted total transmission power of the overlapped bypass signals exceeds the maximum transmission power threshold, the transmission power of the bypass signal corresponding to the lowest priority among the rest of the overlapped bypass signals except the bypass signal whose transmission power is adjusted.

4. A method according to claim 3, wherein the step of adjusting the transmit power of the bypass signal corresponding to the lowest priority among the remaining overlapping bypass signals except for the bypass signal whose transmit power is adjusted is repeated until the adjusted total transmit power of the overlapping bypass signal does not exceed the maximum transmit power threshold.

5. A terminal in a wireless communication system, the terminal comprising:

a memory configured to store computer instructions; and

a processor configured to execute the computer instructions to cause the terminal to perform operations of:

6. The terminal of claim 5, wherein transmissions of bypass signals on the plurality of carriers overlap in time.

7. The terminal of claim 6, wherein the processor is further configured to:

8. The terminal of claim 7, wherein the step of adjusting the transmission power of the bypass signal corresponding to the lowest priority among the remaining overlapped bypass signals except for the bypass signal whose transmission power is adjusted is repeatedly performed until the adjusted total transmission power of the overlapped bypass signals does not exceed the maximum transmission power threshold.