Sidelink positioning in unlicensed band
A method of a first radio node. The method includes: transmitting, from the first radio node, sidelink position reference signal configuration defining at least one position reference signal to be transmitted from a first radio node to the second radio node; generating at least one position reference signal as defined by the SPRS configuration transmitted to the second radio node; performing channel contention for the purpose of position reference signal transmission in a bandwidth range at least partially included in an unlicensed radio band, wherein the contention is performed using a listen before talk mechanism; based on a positive result of the channel contention, accessing the channel for the duration of a channel on time; and transmitting the at least one position reference signal to the second radio node during the channel on time.
1 . A method of a first radio node, comprising the following steps:
transmitting, from the first radio node, a sidelink position reference signal (SPRS) configuration defining at least one position reference signal to be transmitted from a first radio node to the second radio node;
generating at least one position reference signal as defined by the SPRS configuration transmitted to the second radio node;
performing channel contention for the position reference signal transmission in a bandwidth range at least partially included in an unlicensed radio band, wherein the channel contention is performed using a listen before talk mechanism;
based on a positive result of the channel contention, accessing a channel for a duration of a channel on time; and
transmitting the at least one position reference signal to the second radio node during the channel on time.
2 . The method of claim 1 , further comprising:
transmitting, to the second radio node, a periodicity specifier defining a plurality of further position reference signal transmission opportunities of the first radio node, and/or of a plurality of further radio nodes relative to an initial position reference signal transmission opportunity;
performing, at the first radio node, a plurality of further channel contention operations corresponding to each of the plurality of position reference signal transmission opportunities;
based on a positive result of at least one of the further channel contention operations, accessing the channel for the duration of the channel on time; and
transmitting at least one further position reference signal to the second radio node during the channel on time as defined by the periodicity specifier.
3 . The method of claim 1 , further comprising:
transmitting, to the second radio node, a schedule of further position reference signal transmission opportunities of the first radio node and/or of a plurality of further radio nodes;
performing, at the first radio node, a plurality of further channel contention operations corresponding to each of the plurality of further position reference signal transmission opportunities;
based on a positive result of at least one of the further channel contention operation, accessing the channel for the duration of the channel on time; and
transmitting at least one further position reference signal to the second radio node during the channel on time as defined in the schedule of further position reference signal transmission opportunities.
4 . The method of claim 2 ,
wherein the channel contention performed by the first radio node for the position reference signal transmission is a category 4 listen before talk operation, and/or
wherein the channel contention performed by the first radio node for the further position reference signal transmission opportunities is a category 2 listen before talk operation.
5 . The method according to claim 1 , wherein the SPRS configuration transmitted by the first radio node is received in the bandwidth range of the unlicensed radio band, during the channel on time associated with channel contention for control signalling.
6 . The method according to claim 1 , further comprising:
obtaining, from the SPRS configuration, a synchronisation of the at least one position reference signal to at least one transmission opportunity of the side channel, and
when the channel contention for the position reference signal transmission is positive during the at least one transmission opportunity of the side channel:
transmitting the at least one position reference signal to the second radio node during the channel on time.
7 . The method according to claim 1 ,
wherein the SPRS configuration includes an SPRS format definition defining a proportion of resource elements of the unlicensed radio band to be occupied by the at least one position reference signal transmitted by the first radio node; and
transmitting, to the second radio node, at least one position reference signal defined by the SPRS format definition via a plurality of subcarriers in a bandwidth range at least partially includes in the unlicensed radio band.
8 . The method according to claim 7 , wherein the SPRS format definition defines a plurality of subsets of SPRS patterns, wherein each SPRS pattern corresponds to a further radio node in a plurality of further radio nodes, wherein the SPRS format definition transmitted by the first radio node defines an SPRS that is distributed across a predetermined proportion of the unlicensed radio band, wherein the plurality of further radio nodes are configured to interleave their respective SPRS transmissions according to the SPRS format definition to obtain a positive result in a channel contention operation.
9 . The method according to claim 1 , further comprising:
prior to transmitting the SPRS configuration to the second radio node, performing channel contention for control signalling in a bandwidth range at least partially included in the unlicensed radio band using a listen before talk mechanism;
based on a positive result of the channel contention for control signalling, accessing the channel for the duration of a channel on time associated with the channel contention; and
wherein transmitting the SPRS configuration to the second radio node includes transmitting the SPRS configuration, in the bandwidth range of the unlicensed radio band, during the channel on time associated with the channel contention for control signalling.
10 . A method of a second radio node, comprising the following steps:
transmitting, to a first radio node, a sidelink position reference signal (SPRS) configuration defining at least one position reference signal to be transmitted from the first radio node to the second radio node; and
receiving at least one sidelink position reference signal transmitted by the first radio node in a bandwidth range at least partially included in an unlicensed radio band, wherein the at least one sidelink position reference signal is defined according to the SPRS configuration.
11 . The method according to claim 10 ,
wherein the SPRS configuration defines a synchronisation of the at least one position reference signal to at least one transmission opportunity of the side channel, and
wherein the first radio node is configured to receive at least one position reference signal transmitted by the second radio node synchronised to the at least one transmission opportunity of the side channel as defined in the SPRS configuration.
12 . The method according to one of claim 10 ,
wherein the SPRS configuration includes a periodicity specifier defining a plurality of further position reference signal transmission opportunities of the second radio node and/or of a plurality of further radio nodes relative to an initial position reference signal transmission opportunity; and
receiving a plurality of further position reference signals transmitted by a corresponding plurality of further radio nodes, wherein the plurality of further position reference signals occupy a plurality of subcarriers in a bandwidth range at least partially comprised in the unlicensed radio band.
13 . The method according to claim 10 , wherein the SPRS configuration includes a schedule of further position reference signal transmission opportunities of the second radio node and/or of a plurality of further radio nodes.
14 . The method according to claim 10 , wherein the SPRS configuration includes an SPRS format definition defining a proportion of resource elements of the unlicensed radio band to be occupied by the at least one position reference signal transmitted by the second radio node.
15 . The method according to claim 14 , wherein the SPRS format definition defines a plurality of subsets of SPRS patterns, wherein each SPRS pattern corresponds to a further radio node in a plurality of further radio nodes, wherein the SPRS format definition from the first radio node defines an SPRS that is distributed across a predetermined proportion of the unlicensed radio band, wherein the plurality of further radio nodes are configured to interleave their respective SPRS transmissions according to the SPRS format definition to obtain a positive result in a channel contention operation.
16 . A first radio node, comprising:
a radio modem;
non-transitory computer readable media including machine readable instructions; and
a processor configured to load and to execute the machine readable instructions to cause the first radio device to perform the following steps:
transmitting, from the first radio node, a sidelink position reference signal (SPRS) configuration defining at least one position reference signal to be transmitted from a first radio node to the second radio node;
generating at least one position reference signal as defined by the SPRS configuration transmitted to the second radio node;
performing channel contention for the position reference signal transmission in a bandwidth range at least partially included in an unlicensed radio band, wherein the channel contention is performed using a listen before talk mechanism;
based on a positive result of the channel contention, accessing a channel for a duration of a channel on time; and
transmitting the at least one position reference signal to the second radio node during the channel on time.
17 . A second radio node, comprising:
a radio modem;
non-transitory computer readable media including machine readable instructions;
a processor configured to load and to execute the machine readable instructions to cause the second radio device to perform the following steps:
transmitting, to a first radio node, a sidelink position reference signal (SPRS) configuration defining at least one position reference signal to be transmitted from the first radio node to the second radio node; and
receiving at least one sidelink position reference signal transmitted by the first radio node in a bandwidth range at least partially included in an unlicensed radio band, wherein the at least one sidelink position reference signal is defined according to the SPRS configuration.