Methods, apparatuses, and computer readable media for sidelink resource selection
Disclosed are apparatuses for sidelink resource selection. An example apparatus may include at least one processor and at least one memory. The at least one processor may include computer program code, and the at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus to transmit a first sidelink control signal and at least one sidelink data signal in a first beam direction, and transmit a second sidelink control signal in a second beam direction different from the first beam direction. Related methods and computer readable media are also disclosed.
1 . An apparatus comprising:
at least one processor; and
at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to:
transmit a first sidelink control signal and at least one sidelink data signal in a first beam direction, and
transmit a second sidelink control signal in a second beam direction different from the first beam direction,
wherein the at least one memory and the computer program code is configured to, with the at least one processor, further cause the apparatus to perform one of the following:
refrain from transmitting a sidelink data signal associated with the second sidelink control signal in the second beam direction; or transmit a dummy sidelink data signal associated with the second sidelink control signal in the second beam direction,
wherein the dummy sidelink data signal spans at least one sub-channel in a frequency domain, the at least one sub-channel including a frequency span of a physical sidelink control channel for transmitting the first sidelink control signal and being included in a frequency span of a physical sidelink shared channel for transmitting the at least one sidelink data signal.
2 . The apparatus of claim 1 , wherein the first sidelink control signal and the second sidelink control signal are configured with substantially the same time and frequency resource mapping and transmit power density.
3 . The apparatus of claim 1 , wherein no demodulation reference signal is associated with the dummy sidelink data signal.
4 . The apparatus of claim 1 , wherein the second sidelink control signal includes substantially the same information as the first sidelink control signal.
5 . The apparatus of claim 1 , wherein the transmissions in the first beam direction and the second beam direction are millimeter wave sidelink transmissions,
and wherein the transmission in the first beam direction includes at least one of a beamformed unicast sidelink transmission to a target apparatus and a beamformed groupcast sidelink transmission to multiple target apparatuses.
6 . An apparatus, comprising:
at least one processor; and
at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to:
receive a sidelink control signal for a first sidelink transmission through a first receive beam of a plurality of receive beams,
measure a first quality of the received sidelink control signal,
receive a sidelink data signal as scheduled by the sidelink control signal for the first sidelink transmission through the first receive beam,
measure a second quality of the received sidelink data signal, and
select a radio resource for a second sidelink transmission by the apparatus to at least one target apparatus based on at least one of the first quality and the second quality,
wherein selecting the radio resource for the second sidelink transmission comprises:
reusing a radio resource reserved by the sidelink control signal for the first sidelink transmission in a case where the first quality is below a first threshold; else
selecting another radio resource different from the reserved radio resource.
7 . The apparatus of claim 6 wherein, in a case where the first quality is above the first threshold, selecting the radio resource for the second sidelink transmission further comprises:
reusing a radio resource reserved by the sidelink control signal for the first sidelink transmission in a case where a difference between the first quality and the second quality is above a second threshold and the second sidelink transmission is beamformed in a direction different from a direction of the first receive beam; else
selecting another radio resource different from the reserved radio resource.
8 . The apparatus of claim 6 , wherein selecting the radio resource for the second sidelink transmission is further based on relative positions of an apparatus transmitting the sidelink control signal and the at least one target apparatus.
9 . The apparatus of claim 6 , wherein the second sidelink transmission and receptions of the sidelink control signal and the sidelink data signal are millimeter wave sidelink communications,
and wherein the second sidelink transmission comprises at least one of a beamformed unicast sidelink transmission to the at least one target apparatus and a beamformed groupcast sidelink transmission to the at least one target apparatus.
10 . The apparatus of claim 6 , wherein the first quality and the second quality are reference signal received powers measured over demodulation reference signals associated with the sidelink control signal and the sidelink data signal, respectively.
11 . A method, comprising:
transmitting a first sidelink control signal and at least one sidelink data signal in a first beam direction; and
transmitting a second sidelink control signal in a second beam direction different from the first beam direction,
wherein the method further comprises one of the following:
refraining from transmitting a sidelink data signal associated with the second sidelink control signal in the second beam direction; or
transmitting a dummy sidelink data signal associated with the second sidelink control signal in the second beam direction,
wherein the transmissions in the first beam direction and the second beam direction are millimeter wave sidelink transmissions,
and wherein the transmission in the first beam direction includes at least one of a beamformed unicast sidelink transmission to a target apparatus and a beamformed groupcast sidelink transmission to multiple target apparatuses.
12 . The method of claim 11 , wherein the first sidelink control signal and the second sidelink control signal are configured with substantially the same time and frequency resource mapping and transmit power density.
13 . The method of claim 11 , wherein the dummy sidelink data signal spans at least one sub-channel in a frequency domain, the at least one sub-channel including a frequency span of a physical sidelink control channel for transmitting the first sidelink control signal and being included in a frequency span of a physical sidelink shared channel for transmitting the at least one sidelink data signal.
14 . The method of claim 11 , wherein no demodulation reference signal is associated with the dummy sidelink data signal.
15 . The method of claim 11 , wherein the second sidelink control signal includes substantially the same information as the first sidelink control signal.
16 . A non-transitory computer readable medium comprising instructions stored thereon for causing an apparatus to perform the method of claim 11 .
17 . A method, comprising:
receiving a sidelink control signal for a first sidelink transmission through a first receive beam of a plurality of receive beams;
measuring a first quality of the received sidelink control signal;
receiving a sidelink data signal as scheduled by the sidelink control signal for the first sidelink transmission through the first receive beam;
measuring a second quality of the received sidelink data signal; and
selecting a radio resource for a second sidelink transmission to at least one target apparatus based on at least one of the first quality and the second quality,
wherein, in a case where the first quality is above the first threshold, selecting the radio resource for the second sidelink transmission further comprises:
reusing a radio resource reserved by the sidelink control signal for the first sidelink transmission in a case where a difference between the first quality and the second quality is above a second threshold and the second sidelink transmission is beamformed in a direction different from a direction of the first receive beam; else
selecting another radio resource different from the reserved radio resource.
18 . The method of claim 17 , wherein selecting the radio resource for the second sidelink transmission comprises:
reusing a radio resource reserved by the sidelink control signal for the first sidelink transmission in a case where the first quality is below a first threshold; else
selecting another radio resource different from the reserved radio resource.
19 . The method of claim 17 , wherein selecting the radio resource for the second sidelink transmission is further based on relative positions of an apparatus transmitting the sidelink control signal and the at least one target apparatus.
20 . The method of claim 17 , wherein the second sidelink transmission and receptions of the sidelink control signal and the sidelink data signal are millimeter wave sidelink communications,
and wherein the second sidelink transmission comprises at least one of a beamformed unicast sidelink transmission to the at least one target apparatus and a beamformed groupcast sidelink transmission to the at least one target apparatus.
21 . The method of claim 17 , wherein the first quality and the second quality are reference signal received powers measured over demodulation reference signals associated with the sidelink control signal and the sidelink data signal, respectively.
22 . A non-transitory computer readable medium comprising instructions stored thereon for causing an apparatus to perform the method of claim 17 .