WO 2020/029127
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`PCT/CN2018/099443
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`USER EQUIPMENT AND COMMUNICATION METHODS
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`BACKGROUND
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`1. Technical Field
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`The present disclosure relates to wireless communication field, and in particular, to a
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`user equipment (UE) and communication methods related to sensing and resource
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`10
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`selection when beam sweeping is used for New Radio (NR) sidelink.
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`2. Description of the Related Art
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`Beam sweeping has become one of critical
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`issues discussed in 3rd Generation
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`15
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`Partnership Project (3GPP) so far.
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`It
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`is supported in NR in a case of mm Wave
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`assuming analogue beamforming or hybrid beamforming is used in a gNB to guarantee
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`the coverage, which means the gNB sweepsa plurality of differently directed beams to
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`fully cover a cell it serves.
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`20
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`For NR sidelink-based Vehicle to Everything (V2X), beam sweeping will be applied in a
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`case that analogue beamforming or hybrid beamforming is used in vehicles as well. So
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`far,
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`it
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`is still under discussion about the design of sensing and resource selection
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`behavior to support beam sweeping in NR sidelink-based V2xX.
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`SUMMARY
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`One non-limiting and exemplary embodimentfacilitates sensing and resource selection
`
`for transmission using beam sweeping in NR sidelink-based V2xX.
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`In a general aspect of the present disclosure,
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`there is provided a user equipment,
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`comprising: a receiver, operative to receive transmissions of a Transport Block (TB)
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`performed by another UE using each of a first set of beams respectively; circuitry,
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`operative to perform measurement on the received transmissions, and to select
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`resource for
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`sidelink transmission among candidate
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`resources based on
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`a
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`measurement result; and a transmitter, operative to perform the sidelink transmission
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`with the selected resource, wherein, the circuitry is further operative to preclude, from
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`the candidate resources, one or more candidate resources associated with a
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`transmission using a beam of the first set of beams, if the measurement result of the
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`10
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`transmission using the beam fulfills a predetermined condition.
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`In another general aspect of the present disclosure, there is provided a communication
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`method, comprising: receiving, at a UE, transmissions of a TB performed by another
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`UE using each of a first set of beams respectively; performing measurement on the
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`15
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`received transmissions, and selecting resource for sidelink transmission among
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`candidate resources based on a measurement result; and performing the sidelink
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`transmission with the selected resource, wherein,
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`the method further comprises
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`precluding, from the candidate resources, one or more candidate resources associated
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`with a transmission using a beam ofthefirst set of beams, if the measurement result of
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`20
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`the transmission using the beam fulfills a predetermined condition.
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`In another general aspect of the present disclosure, there is provided a user equipment,
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`comprising: a receiver, operative to perform sidelink reception from a second UE,
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`wherein,
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`the sidelink reception is performed with resource which is selected by the
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`25
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`second UE among candidate resources based on a measurement
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`result,
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`the
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`measurement result being obtained by the second UE performing measurement on
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`transmissions of a TB received from a third UE and performed by the third UE using
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`each of a first set of beams respectively, and wherein, one or more candidate
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`resources associated with a transmission by the third UE using a beam of the first set
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`of beamsare precluded from the candidate resources, if the measurement result of the
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`transmission by the third UE using the beam fulfills a predetermined condition.
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`In another general aspect of the present disclosure, there is provided a communication
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`method, comprising: performing, at a UE, sidelink reception from a second UE, wherein,
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`the sidelink reception is performed with resource which is selected by the second UE
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`among candidate resources based on a measurement result, the measurement result
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`being obtained by the second UE performing measurement on transmissions of a TB
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`received from a third UE and performed by the third UE using each of a first set of
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`10
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`beams respectively, and wherein, one or more candidate resources associated with a
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`transmission by the third UE using a beam ofthe first set of beams are precluded from
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`the candidate resources, if the measurement result of the transmission by the third UE
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`using the beam fulfills a predetermined condition.
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`15
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`It should be noted that general or specific embodiments may be implemented as a
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`system, a method, an integrated circuit, a computer program, a storage medium, or any
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`selective combination thereof.
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`Additional benefits and advantages of
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`the disclosed embodiments will become
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`20
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`apparent from the specification and drawings. The benefits and/or advantages may be
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`individually obtained by the various embodiments and features of the specification and
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`drawings, which need not all be provided in order to obtain one or more of such
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`benefits and/or advantages.
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`BRIEF DESCRIPTION OF DRAWINGS
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`The foregoing and other features of the present disclosure will become more fully
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`apparentfrom the following description and appended claims, taken in conjunction with
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`the accompanying drawings. Understanding that these drawings depict only several
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`30
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`embodiments
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`in accordance with the disclosure and are,
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`therefore, not
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`to be
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`considered limiting of
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`its scope,
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`the disclosure will be described with additional
`
`specificity and detail through use of the accompanying drawings, in which:
`
`Fig.
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`1 schematically shows an exemplary scenario of candidate resource precluding
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`when beam sweeping is applied;
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`Fig. 2 illustrates a block diagram of a user equipment according to an embodiment of
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`the present disclosure;
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`Fig. 3 schematically shows an exemplary scenario of candidate resource precluding
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`when beam sweeping is applied in NR sidelink according to an embodiment of the
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`10
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`presentdisclosure;
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`Fig. 4 schematically shows resource positions in frequency domain and time domain of
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`initial
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`transmissions and corresponding retransmissions using a plurality of beams
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`according to an embodimentof the present disclosure;
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`Fig. 5 schematically shows an exemplary scenario of resource selection when beam
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`sweeping is applied in NR sidelink according to an embodiment of the present
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`disclosure;
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`Fig. 6 schematically shows NR Synchronization Signal
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`(SS)/ Physical Broadcast
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`Channel (PBCH) allocation in Uu carrier according to one embodiment of the present
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`disclosure;
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`20
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`Fig. 7 schematically shows NR sidelink SS/ Physical Sidelink Broadcast Channel
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`(PSBCH) allocation in
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`ITS (intelligent
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`transportation system) carrier according to
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`another embodiment of the present disclosure;
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`Fig. 8 schematically shows a detailed block diagram of a user equipment according to
`
`an embodimentof the present disclosure;
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`25
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`Fig. 9 schematically shows a flowchart of a communication method according to an
`
`embodiment of the present disclosure;
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`Fig. 10 illustrates a block diagram of a user equipment according to an embodimentof
`
`the present disclosure; and
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`Fig. 11 schematically shows a flowchart of a communication method according to an
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`30
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`embodiment of the present disclosure.
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`DETAILED DESCRIPTION
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`In the following detailed description, reference is made to the accompanying drawings,
`
`which form a part thereof.
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`In the drawings, similar symbols typically identify similar
`
`components, unless context dictates otherwise.
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`It will be understood that the aspects
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`of the present disclosure can be arranged, substituted, combined, and designed in a
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`wide variety of different configurations, all of which are explicitly contemplated and
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`makepart of this disclosure.
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`10
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`In LTE V2X, retransmission is supported for a certain TB transmission to solve half
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`duplex issue which meansthat a UE could not transmit and receive at the same time in
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`a carrier due to RF constraint.
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`In case a certain UE (e.g., UE2) misses one TB (e.g.,
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`initial transmission) from another UE (e.g., UE1) due to various reasons such as a
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`15
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`transmission by the UEZ2itself, UE2 maystill be able to receive the TB from UE1 (e.g.,
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`via retransmission).
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`In addition, a resource for initial
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`transmission of a TB and a
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`resource for retransmission of the same TB are separately selected from a candidate
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`resource set within a resource selection window.
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`20
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`For NR sidelink-based Vehicle to Everything (V2X), beam sweeping will be applied in a
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`case that analogue beamforming or hybrid beamforming is used in vehicles as well.
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`In
`
`order to support beam sweeping, a UE may performinitial transmissions of a TB using
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`each of a set of beams respectively, and perform retransmissions of the same TB using
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`each of the set of beams respectively, wherein the set of beams includes one or more
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`25
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`differently directed beams.
`
`So far,
`
`it is still under discussion about the design of sensing and resource selection
`
`behavior to support beam sweeping in NR sidelink-based V2X. During sensing and
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`resource selection procedure, a UE may sense a plurality of resources during a
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`30
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`sensing window; preclude, from a candidate resource set included within a resource
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`selection window, one or more candidate resources that are unsuitable or improper for
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`transmitting a current traffic based on a sensing result;
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`rank candidate resources
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`remaining in the candidate resource set suffered preclusion; and select,
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`from the
`
`candidate resources remaining in the candidate resource set, one or more resources
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`for transmitting the currenttraffic based on a ranking result.
`
`It should be noted that,
`
`the embodiments herein disclosed are applicable to V2XxX
`
`(Vehicle to Everything) that includes but not limited to V2I (vehicle to infrastructure),
`
`V2P (vehicle to pedestrian), V2V (vehicle to vehicle), and any other communication
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`10
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`using NR sidelink.
`
`Fig.
`
`1 schematically shows an exemplary scenario of candidate resource precluding
`
`when beam sweeping is applied. VWWhen a certain UE (i.e., UE2) senses transmissions
`
`of a certain TB performed by another UE (i.e., UE1) using a set of beams, for example,
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`15
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`at least one ofinitial transmissions of the TB and retransmissions of the same TB using
`
`the set of beams, the UE2 may assume all sensed transmissions related to the same
`
`TB have same power,
`
`for example, both of
`
`the initial
`
`transmissions and the
`
`retransmissions are assumed to have same power. Further, the UE2 may assume that
`
`the UE1 will periodically perform transmissions. Therefore,
`
`to avoid possible large
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`20
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`interference during transmission by the UE2,
`
`the UE2 may preclude candidate
`
`resources which are associated with all transmissions using the set of beams to be
`
`performed by the UE1 for next several transmission periods falling within the resource
`
`selection window of the UE2,
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`if any one of the sensed transmissions is sensed to have
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`large interference. The interference may be determined by performing measurement on
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`25
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`the sensed transmissions. For example, the UE1 is determined to be an interfering UE
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`to the UE2 if a measurementresult of Reference Signal Received Power (RSRP) of
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`sidelink SS or PSBCH measured by UE2 on any one of the sensed transmissions
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`exceeds a certain threshold.
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`As shown in Fig. 1, UE1 is sensed by UE2 as an interfering UE during sensing
`
`procedure of the UEZ2. It is assumed that the UE1 transmits its traffic periodically. In an
`
`embodiment,
`
`the UE1 has a set of beams including, for example,
`
`two beams, i.é.,
`
`Beam 1 and Beam 2.
`
`In one example, the UE1 performs initial transmissions using
`
`Beam 1 and Beam 2 without any retransmission. In another example, for each of Beam
`
`1 and Beam 2, the UE1 performs both initial transmission and retransmission for a
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`certain TB.
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`In the latter case, the UE1 totally transmits the same TB for four times in
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`different
`
`time. For a current traffic of the UE2, a sensing window for the UE2 is
`
`configured, preconfigured or specified as a time interval from a timing (n-a) to a timing
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`10
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`n, Le.,
`
`the time interval
`
`[n-a, n], and a resource selection window for the UEZ2is
`
`configured, preconfigured or specified as a time interval [n+T,, n+T2], both of which are
`
`specified in the specification 3GPP TS 36.213_v15.1.0, wherein the timing n is a timing
`
`of resource selection trigger for the currenttraffic indicated by a higher layer signaling.
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`15
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`In the case of the UE1 performing both the initial transmissions and retransmissions for
`
`the TB, when any one of initial transmission using Beam 1,
`
`initial transmission using
`
`Beam 2, retransmission using Beam 1 and retransmission using Beam 2, for example,
`
`initial transmission using Beam 1 as shownin Fig. 1,
`
`is sensed by the UE2 as large
`
`interference, the UE2 may predict certain candidate resources, at resource positions in
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`20
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`time domain which are overlapped with those where the UE1 are assumed to perform
`
`the initial
`
`transmissions and the retransmissions periodically during the resource
`
`selection window of the UE2, would be potentially subject to large interference from the
`
`UE1,
`
`since the UE1
`
`is assumed to perform the initial
`
`transmission and the
`
`retransmission periodically, and the initial
`
`transmission and the retransmission
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`25
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`associated with the same TB have same power. Accordingly, the UE2 may preclude
`
`the certain candidate resources associated with initial transmissions using Beams 1
`
`and 2 and retransmissions using Beams1 and 2. Thatis, all of candidate resources 1-8
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`as shownin Fig. 1 willbe precluded according to this embodiment, for example.
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`However, differently directed beams in the set of beams of the UE1 may havedifferent
`
`interference to the UE2. For example, initial transmission or retransmission using Beam
`
`1 may generate interference to transmission behavior of the UE2. On the other hand,
`
`initial transmission or retransmission using Beam 2 may not cause interference or may
`
`cause interference that is small enough to be ignored for current transmission of the
`
`UE2.
`
`In this case, precluding all of candidate resources 1-8 would result in a waste of
`
`resources in the resource selection window.
`
`In view of
`
`the above,
`
`in order to facilitate sensing and resource selection for
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`10
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`transmission using beam sweeping in NR sidelink-based V2X, in an embodiment of the
`
`present disclosure,
`
`there is provided a user equipment as shown in Fig.2. Fig.2
`
`illustrates a block diagram of a part of a user equipment 200 according to an
`
`embodiment of the present disclosure.
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`15
`
`As shown in Fig. 2,
`
`the UE 200 may include a receiver 210, circuitry 220 and a
`
`transmitter 230.
`
`In an embodiment,
`
`the receiver 210 is operative to receive
`
`transmissions of a TB performed by another UE (i.e., UE1) using each ofa first set of
`
`beams respectively. The circuitry 220 is operative to perform measurement on the
`
`received transmissions, and to select
`
`resource for sidelink transmission among
`
`20
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`candidate resources based on a measurement result.
`
`In an embodiment, the circuitry
`
`220 is further operative to preclude,
`
`from the candidate resources, one or more
`
`candidate resources associated with a transmission using a beam ofthe first set of
`
`beams,
`
`if
`
`the measurement
`
`result of the transmission using the beam fulfills a
`
`predetermined condition. The transmitter 230 in the UE 200 is operative to transmit the
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`25
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`traffic by using the selected resources.
`
`In an embodiment, receiving transmissions of a TB performed by another UE using
`
`each of a first set of beams respectively comprises: receiving at least one ofinitial
`
`transmissions of the TB and retransmissions of the same TB using each of the first set
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`30
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`of beams respectively. Further, precluding one or more candidate resources associated
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`with a transmission using a beam ofthe first set of beams comprises: precluding one or
`
`more candidate resources associated with at
`
`least one of initial
`
`transmission and
`
`retransmission using the beam of the first set of beams.
`
`In an embodiment,
`
`the beam of the first set of beams with which the one or more
`
`candidate resources to be precluded are associated (hereinafter
`
`referred to as
`
`“associated beam’) is determined by measuring RSRP of sidelink SS or PSBCH for the
`
`received transmissions performed by the UE1 using the first set of beams.
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`10
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`As described above, differently directed beamsin the first set of beams of the UE1 may
`
`have different interference to the UE 200, thus the UE 200 may not need to consider
`
`interference from all beams in the first set of beams of the UE1. In other words, in order
`
`to avoid wasting candidate resources within a resource selection window, the UE 200
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`precludes one or more candidate resources related to the associated beam instead of
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`15
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`related to all beams in the first set of beams of the UE1. More details of the associated
`
`beam will be discussed later with reference to Fig. 3.
`
`In an embodiment, if the UE2 receives transmissions of a certain TB performed by the
`
`UE1 using each of a first set of beams respectively during sensing procedure of the
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`20
`
`UE2,
`
`the UE2 may assume that the UE1 will perform transmissions periodically.
`
`In
`
`order to avoid possible large interference during transmission by the UEZ2 itself, the
`
`UE2 may preclude candidate resources associated with transmissions using the
`
`associated beam in the first set of beams to be performed by the UE1 for next several
`
`transmission periods falling within the resource selection window of the UE2,
`
`if the
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`25
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`received transmission using the associated beam is sensed to have large interference.
`
`In an example, transmissions of a certain TB performed by the UE1 comprise only
`
`initial transmissions using each ofthe first set of beams respectively.
`
`In this case, the
`
`UE2 may receive only those initial transmissions, and further preclude candidate
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`resources associated with initial
`
`transmissions using the associated beam to be
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`10
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`performed during the resource selection window of the UE2, if a measurementresult of
`
`the received transmission using the associated beam fulfills a predetermined condition.
`
`In another example, transmissions of a certain TB performed by the UE1 comprise both
`
`initial
`
`transmissions using each of
`
`the first
`
`set of beams
`
`respectively and
`
`retransmissions using eachofthe first set of beams respectively. In this case, the UE2
`
`may receive at
`
`least one of the initial
`
`transmissions and the retransmissions, and
`
`further preclude candidate resources associated with initial
`
`transmissions and
`
`retransmissions using the associated beam to be performed during the resource
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`10
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`selection window of the UE2, if a measurementresult of the received at least one of the
`
`initial
`
`transmission and the retransmission using the associated beam fulfills a
`
`predetermined condition.
`
`Fig. 3 schematically shows an exemplary scenario of candidate resource precluding
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`15
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`when beam sweeping is applied in NR sidelink according to an embodiment of the
`
`presentdisclosure. It is assumed that beam sweeping is used by a UE1 shown in Fig. 3
`
`for each channel transmission when analogue beamforming or hybrid beamforming is
`
`applied to the UE1.
`
`In addition, a UE 2 shownin Fig. 3 may be implemented, for
`
`example, as the UE 200 shownin Fig. 2.
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`20
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`As shownin the example of Fig. 3, the UE1 is sensed by the UE2 as an interfering UE
`
`during sensing procedure of the UE2.
`
`In an embodiment, the UE1 has a set of beams
`
`including, for example, two beams, i.e., Beam 1 and Beam 2. In one example, the UE1
`
`performs initial transmissions using Beam 1 and Beam 2 respectively without any
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`25
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`retransmission. In another example, for each of Beam 1 and Beam 2, the UE1 performs
`
`both initial transmission and retransmission. In the latter case, the UE1 totally transmits
`
`the same TB for four times in different time,
`
`i.e.,
`
`initial transmission using Beam 1,
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`initial transmission using Beam 2, retransmission using Beam 1 and retransmission
`
`using Beam 2. The following description is made by taking the UE1 performing both
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`11
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`initial transmissions and retransmissions as an example only for illustrative purpose,
`
`but not limited thereto.
`
`It should be noted that two beams of the UE1 as shown in the example of Fig. 3 are
`
`only illustrative, but not limited thereto. For example, the number of beams in the first
`
`set of beams of the UE71 is not
`
`limited to two, and may be any suitable number
`
`depending on design requirement, according to the embodiments of the present
`
`disclosure. For example,
`
`in an embodiment,
`
`the first set of beams of the UE1 may
`
`include only one beam, three or more beams.
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`10
`
`It should also be noted that the initial transmissions using each of the first set of beams
`
`respectively and the retransmissions using each ofthe first set of beams respectively
`
`as shown in example of Fig. 3 are only illustrative, but not limited thereto.
`
`In other
`
`words, beams used for initial transmissions of the TB may be different from beams
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`15
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`used for the retransmissions of the same TB. In an embodiment, the first set of beams
`
`of
`
`the UE1 may be divided into two subsets of which one is used for
`
`initial
`
`transmissions and the other one is used for retransmissions. For example,
`
`it
`
`is
`
`assumedthat the UE1 hasa first set of beams including five beams, of which three are
`
`considered asa first subset of beams usedfor initial transmissions, and the other two
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`20
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`are considered as a second subset of beams used for retransmissions. Optionally,
`
`each beam in the second subset of beams used for retransmissions may be a little
`
`wider than thatin the first subset of beams used for initial transmissions.
`
`For a currenttraffic of the UE2,
`
`in order to sense and select resource for transmitting
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`25
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`the current
`
`traffic, a sensing window for the UE2 is configured, preconfigured or
`
`specified, for example, as a time interval from a timing (n-a) to a timing n, i.e., the time
`
`interval
`
`[n-a, n], and a resource selection window for
`
`the UE2 is configured,
`
`preconfigured or specified, for example, as a time interval [n+T,, n+T2], wherein the
`
`timing n is a timing of resource selection trigger for the current traffic indicated by a
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`higher layer signaling.
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`12
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`In an embodiment,
`
`the receiver 210 of the UE 2 receives at
`
`least one of initial
`
`transmissions using Beams 1 and 2 and retransmissions using Beams 1 and 2.
`
`In an
`
`example, the receiver 210 of the UE 2 may receive both ofinitial transmissions using
`
`Beams 1 and 2 and retransmissions using Beams 1 and 2.
`
`In another example, the
`
`receiver 210 of the UE 2 may receive only initial transmissions using Beams 1 and 2
`
`and misses retransmissions using Beams 1 and 2. In still another example, the receiver
`
`210 of the UE 2 may receive only retransmissions using Beams 1 and 2 and misses
`
`initial transmissions using Beams 1 and 2. In either of the latter two cases, as long as
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`10
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`the UE2 detects positions in time domain for any one ofthe initial transmissions and
`
`the corresponding retransmissions of the UE1, the UE2 can derive positions in time
`
`domain for
`
`the other one of
`
`the initial
`
`transmissions and the corresponding
`
`retransmissions of the UE1, based on an indication in Physical Sidelink Control
`
`Channel (PSCCH) of the UE1. That
`
`is, a transmission interval between the initial
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`15
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`transmission and the corresponding retransmission using the same beam is indicated
`
`in PSCCH of the UE1, for example, in Sidelink Control Information (SCI) transmitted on
`
`PSCCH of the UE1.
`
`After
`
`receiving at
`
`least one of
`
`initial
`
`transmissions using Beams 1 and 2 and
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`20
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`retransmissions using Beams 1 and 2 from the UE1,
`
`the circuitry 220 of the UE 2
`
`performs measurement on the received at
`
`least one of initial
`
`transmissions using
`
`Beams 1 and 2 of the UE1 and retransmissions using Beams 1 and 2 of the UE1, and
`
`then selects resource for sidelink transmission among candidate resources within the
`
`resource selection window based on a measurement result.
`
`In one embodiment, the
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`25
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`circuitry 220 of the UE2 performs RSRP measurement to obtain the measurement
`
`result.
`
`In the resource selection window shownin Fig. 3, only candidate resources 1 to 8 are
`
`shown for illustrative purposes. However, the number of candidate resources in the
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`30
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`resource selection window of the UE2 is notlimited to 8, and there can be any number
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`of candidate resources depending on practical applications and scenarios according to
`
`the embodiments of the present disclosure.
`
`In an embodiment,
`
`the circuitry 220 of the UE2 may preclude, among candidate
`
`resources 1
`
`to 8, one or more candidate resources associated with initial transmission
`
`and corresponding retransmission using an associated beam in the first set of beams of
`
`the UE1. The associated beam refers to a beam using which periodic initial
`
`transmission or periodic retransmission of the UE1 may cause large interference to the
`
`UE2 when resource positions of candidate resources in time domain overlap with
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`10
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`resource
`
`positions where
`
`the
`
`periodic
`
`initial
`
`transmission
`
`and the
`
`periodic
`
`retransmission are predicted to be performed during the resource selection window of
`
`the UE2.
`
`Furthermore,
`
`in an embodiment, the associated beam is determined by the circuitry
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`15
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`220 of the UE2 measuring RSRP of sidelink SS or PSBCH for the at least one ofinitial
`
`transmissions using Beams 1 and 2 and retransmissions using Beams 1 and 2
`
`received from the UE1, assuming the UE1 sweeps Beam 1 and Beam 2 for sidelink SS
`
`or PSBCH transmission.
`
`In one example,
`
`initial
`
`transmission and corresponding
`
`retransmission of a same TB are assumed to have same power. In this case, if the UE2
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`20
`
`receives both the initial transmission and the retransmission, the UE2 may obtain a
`
`measurement result for the other one of the initial transmission and the retransmission
`
`with performing measurement on only one of
`
`the initial
`
`transmission and the
`
`retransmission.
`
`In another example, the initial transmission and the retransmission are
`
`assumed to have different powers, and the power difference between the initial
`
`25
`
`transmission and the retransmission is indicated by control signaling (¢.g., PSCCH or
`
`higher layer signaling) or specified in the specification.
`
`In this case, if the UE2 receives
`
`both the
`
`initial
`
`transmission and the
`
`retransmission,
`
`the UE2 may obtain a
`
`measurement result for the other one of the initial transmission and the retransmission
`
`based on the power difference with performing measurement on only one ofthe initial
`
`30
`
`transmission and the retransmission.
`
`In still another example, the initial transmission
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`and the retransmission are assumed to have different powers which are independent
`
`from each other.
`
`In this case, if the UE2 receives both the initial transmission and the
`
`retransmission, the UE2 needs to perform measurement on boththe initial transmission
`
`and the retransmission respectively,
`
`in order to determine the associated beam. The
`
`following description is made by taking the initial transmissions and the corresponding
`
`retransmissions having the same power as an example only for illustrative purpose, but
`
`not limited thereto.
`
`As shown in Fig. 3, after sidelink SSs or PSBCHsfor the initial transmission using
`
`10
`
`Beam 1 and the initial
`
`transmission using Beam 2 transmitted from the UE1 are
`
`measured respectively by the circuitry 220 of the UE2 during the sensing window,for
`
`example, the initial transmission using Beam 1
`
`is determinedto fulfill a predetermined
`
`condition which indicates large interference to the UE2.
`
`In this case, the UE2 predicts
`
`the initial transmission using Beam 1 and the retransmission using Beam 1
`
`to be
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`15
`
`performed by the UE1 periodically during the resource selection window of the UE2
`
`may cause large interference to current transmission of the UE2. On the other hand,
`
`the UEZ2predicts the initial transmission using Beam 2 and the retransmission using
`
`Beam 2 to be performed by the UE1 periodically during the resource selection window
`
`of the UE2 may not cause interference or may causeinterference that is small enough
`
`20
`
`to be ignored for current transmission of the UEZ2.
`
`In this sense, Beam 1
`
`in the first set
`
`of the UE1 is determined by the UE2 as the associated beam to be usedfor precluding
`
`candidate resources within the resource selection window of the UE2.
`
`In an embodiment, the predetermined condition, which indicates large interference to
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`25
`
`current
`
`transmission of the UE2,
`
`is that
`
`the measured RSRP exceeds a certain
`
`threshold.
`
`In the example of Fig.3, the measured RSRP of sidelink SS or PSBCH for
`
`the initial transmission using Beam 1 exceeds the certain threshold. In an embodiment,
`
`the certain threshold may vary depending on practical applications and scenarios. For
`
`example, a corresponding threshold may be configured or preconfigured for a certain
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`30
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`value of ProSe Per-Packet Priority (PPPP) of the traffic to be transmitted currently by
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`the UE2. Further,it is to be noted that the predetermined condition is not limited to the
`
`measured RSRP exceeding a certain threshold, as long as it can indicate large
`
`interference to current transmission of the UE2.
`
`After the associated beam, for example Beam 1
`
`in the example of Fig. 3, in the first set
`
`of beamsof the UE1 is determined, the circuitry 220 of the UE2 precludes one or more
`
`candidate
`
`resources
`
`associated with
`
`initial
`
`transmission
`
`and
`
`corresponding
`
`retransmission using the associated beam. For example, assuming UE1 perform the
`
`initial transmission and the retransmission periodically, the UE2 may predict resource
`
`10
`
`positions in time domain where the UE1 will perform the initial transmission(s) and the
`
`retransmission(s) using the associated beam for next K transmission periods within the
`
`resource selection window of the UE2, according to resource position of received at
`
`least one of the initial transmission or the retransmission using the associated beam,
`
`wherein K is an integer greater than zero. In one embodiment, the transmission period
`
`15
`
`(for example, 20ms) of the UE1 is indicated in PSCCH of the UE1, for example, in SCI
`
`transmitted on PSCCH of the UE1. Furthermore, after the prediction described above,
`
`the UE2 determines that certain candidate resources at those predicted resource
`
`positions in time domain (if any) would be potentially subject to large interference from
`
`the UE1, since at least one of the initial transmission or the retransmission using the
`
`20
`
`associated beam received from the UE1 during the sensing window of the UE2 has
`
`been sensed to having large interference to the UE2. As a result, the certain candidate
`
`resources of the UE2, at those predicted resource positions in time domain whereit is
`
`predicted that the UE1 would perform the initial transmission and the retransmission
`
`using the associated beam, are determined to be associated with the_initial
`
`25
`
`transmission and the retransmission using the associated beam and are to be
`
`precluded by the UE2.
`
`For example, as shownin Fig. 3, two (i.e., K=2) transmission periods of the UE1 are
`
`included within the resource selection window of the UE2. That
`
`is,
`
`the predicted
`
`30
`
`resource positions in time domain where the UE1 is predicted to perform the initial
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`transmission using Beam 1, the initial transmission using Beam 2, the retransmission
`
`using Beam 1 and the retransmission using Beam 2 for the next one period overlap
`
`with resource positions of candidate resources 1, 2, 3, and 4 in time domain
`
`respectively, and the predicted resource positions in time domain where the UE1 is
`
`predicted to perform the initial transmission using Beam 1, the initial transmission using
`
`Beam 2, the retransmission using Beam 1 and the retransmission using Beam 2 for the
`
`next two period overlap with resource positions of candidate resources 5, 6, 7, and 8 in
`
`time domain respectively.
`
`10
`
`As discussed above, Beam 1 of the UE1 is determined as the associated beam, thus
`
`the candidate resources 1, 3, 5, and 7 are precluded. For example,
`
`the candidate
`
`resources 1 and 5 are precluded since the