Asset tracking joint sounding reference signal (SRS) transmission
Systems, methods, apparatuses, and computer program products for asset tracking joint sounding reference signal (SRS) transmission. A location management network node may send a positioning failure message to a serving network node. The serving network node may group devices if one or more criteria are met. When one or more of the devices can be grouped, the serving network node may assign and distribute, to devices, a multi-tag-SRS sequence identifier that may be used by the devices in the group. The serving network node may compute and send, to the devices in the group, a multi-tag-SRS transmit configuration. The devices may perform a joint SRS transmission. The location management network node may compute a location of a centroid for the group of devices associated with the reported metric.
1 . A method, comprising:
receiving, by a wireless handheld device, in downlink control signaling from a serving network node, a configuration message associated with configuring a group of devices to transmit a joint uplink sounding reference signal (SRS), wherein the group of devices is based on one or more criteria;
receiving, by the wireless handheld device, in the configuration message or in another downlink signaling message from the serving network node, an identifier for the joint uplink SRS, the configuration message further comprising device-specific uplink transmission configuration parameters including at least one of: a transmit precoder, a timing advance, or transmit power control parameters;
processing, by the wireless handheld device, the identifier and the device-specific uplink transmission configuration parameters to generate a joint uplink SRS for the device, including selecting a sequence corresponding to the identifier and applying the device-specific transmit precoder, timing advance, and/or transmit power control parameters to the joint uplink SRS prior to transmission; and
transmitting, by the wireless handheld device, the joint uplink SRS to the serving network node on an uplink channel according to the configuration, wherein transmitting the joint uplink SRS comprises transmitting the joint uplink SRS to the serving node according to a sequence associated with the identifier and applying the device-specific uplink transmission configuration parameters to the joint uplink SRS transmission.
2 . The method according to claim 1 , wherein at least one of the devices of the group of devices is associated with the serving network node and at least one of the devices of the group of devices is associated with one or more other serving network nodes.
3 . The method according to claim 2 , wherein the one or more criteria comprise whether the group of devices: share a common serving beam index, have a similar value for a quality metric, have similar timing advances or a standard deviation of the timing advances in the group of devices is smaller than a threshold value, and experience similar propagation conditions.
4 . The method according to claim 1 , wherein the transmitting the joint uplink SRS comprises applying a device-specific transmit precoder provided by the serving network node.
5 . The method according to claim 1 , wherein the identifier for the joint uplink SRS comprises a multi-tag-SRS sequence identifier distributed by the serving network node to the devices of the group.
6 . The method according to claim 1 , wherein the device-specific transmission configuration parameters comprise at least one of: a transmit precoder, a timing advance, or transmit power control parameters.
7 . The method according to claim 1 , further comprising receiving, at the wireless handheld device, a configuration message comprising the identifier and the device-specific transmission configuration parameters.
8 . The method according to claim 1 , wherein the service network node performs measurements of the joint uplink SRS to determine at least one of: an angle of arrival (AoA) or a time of arrival (ToA) of the joint uplink SRS.
9 . The method according to claim 1 , wherein the service network node reports measurements of the joint uplink SRS to a location management network node, and the location management network node determines a centroid location of the group of devices.
10 . The method according to claim 1 , wherein the wireless handheld device is an IoT asset tracking tag device configured for uplink SRS positioning.