BACKGROUND

The following relates generally to wireless communications, and more specifically to positioning with relays.

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM).

A wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). A wireless communications network may implement techniques to keep track of the position of a UE in the wireless communications network. Additionally, in some cases, the wireless communications network may utilize relays to increase coverage for uplink data transmissions, downlink data transmissions, or both, where the different data transmissions are routed through a relay rather than travelling directly between a base station and a UE. However, the utilization of relays in a wireless communications network may interfere with keeping track of the position of the UE based on the UE and/or base station not knowing whether signals used for determining the position of the UE are coming from a transmitting node (e.g., a base station or a UE) or from a relay.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support positioning with relays. Generally, the described techniques provide for determining a position of a user equipment (UE) when communications between the UE and a base station are routed through a relay node. In some implementations, a location server may store positioning assistance data (e.g., almanac information, such as a base station almanac (BSA)) that contains positioning-related information (e.g., cell identifiers, UE identifiers, geographic locations, beam identifiers, backhaul beams, access beams, node types, etc.) about different base stations and relay nodes in a wireless communications system. The location server may transmit this positioning assistance data to the UE via the base station and the relay (e.g., via a Long Term Evolution (LTE) positioning protocol (LPP) message and connection with the UE). In some cases, the UE may then receive one or more position reference signals (PRSs) and may use the positioning assistance data to determine whether the PRSs are received from the base station or the relay node. Accordingly, the UE may generate a positioning metric based on determining whether the PRSs are received from the base station or the relay and may transmit the positioning metric to the location server (e.g., via the relay node and the base station), where the location server determines the location of the UE based on the positioning metric. For example, the positioning metric may include a detected time of arrival, an angle of arrival, or both.

In some cases, the UE may determine whether the PRSs are received from the base station or the relay node based on a delay associated with the PRSs (e.g., PRSs routed through the relay node may have a longer delay time); an orientation, attenuation, or both for an angle of incidence for the relay node included in the almanac information; a PRS identifier or scrambling code associated with the PRSs that identify which of the base station or relay node are transmitting the PRSs; or a combination thereof. Additionally or alternatively, the UE may determine the position metric based on hypotheses that the PRSs are received from either the base station or the relay node, where the UE determines one or more candidate positioning metrics (e.g., or pairs of candidate positioning metrics) based on the hypotheses. The UE may then select a candidate positioning metric from the hypotheses as the positioning metric (e.g., a round trip time (RTT) positioning metric) based on an outlier rejection scheme. In some cases, the base station may perform a similar determination process to generate a position metric based on receiving a PRS from the UE and using the almanac information. The base station may then transmit the position metric to the location server to enable the location server to determine the location (e.g., position) of the UE.

A method of wireless communications by a UE is described. The method may include receiving positioning assistance data (e.g., almanac information) that indicates that a first node operates as a relay for a second node (e.g., that operates as a base station), receiving a PRS, and generating a positioning metric based on the positioning assistance data and the PRS.

An apparatus for wireless communications by a UE is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive positioning assistance data (e.g., almanac information) that indicates that a first node operates as a relay for a second node (e.g., that operates as a base station), to receive a PRS, and to generate a positioning metric based on the positioning assistance data and the PRS.

Another apparatus for wireless communications by a UE is described. The apparatus may include means for receiving positioning assistance data (e.g., almanac information) that indicates that a first node operates as a relay for a second node (e.g., that operates as a base station), means for receiving a PRS, and means for generating a positioning metric based on the positioning assistance data and the PRS.

A non-transitory computer-readable medium storing code for wireless communications by a UE is described. The code may include instructions executable by a processor to receive positioning assistance data (e.g., almanac information) that indicates that a first node operates as a relay for a second node (e.g., that operates as a base station), to receive a PRS, and to generate a positioning metric based on the positioning assistance data and the PRS.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the PRS is received from the first node based on the positioning assistance data and generating the positioning metric based on determining that the PRS is received from the first node.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the PRS is received from the second node based on the positioning assistance data and generating the positioning metric based on determining that the PRS is received from the second node.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for selecting a third node to monitor that is not associated with a relay node based on the positioning assistance data, where the PRS is received from the third node.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the positioning assistance data may include a first node type that indicates the first node is a relay node and a second node type that indicates that the second node is a base station.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for processing the positioning assistance data to determine one or more of a cell identifier, a UE identifier, a geographic location, or a beam identifier, for the first node, the second node, or both.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for processing the positioning assistance data to determine one or more of an antenna array configuration, an antenna panel configuration, an orientation, the first node, a beam pattern, a backhaul beam, or an access beam, for the first node, the second node, or both.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for processing the positioning assistance data to determine a backhaul gain between the first and second nodes, an access gain between the first node and the UE, or both.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for processing the positioning assistance data to determine the first node is an active relay or a passive relay.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for processing the positioning assistance data to determine an orientation, attenuation, or both, for at least one angle of incidence for the first node.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for processing the positioning assistance data to determine delay introduced by the first node when relaying a transmission.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the positioning metric may include a detected time of arrival, an angle of arrival, or both.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the PRS is from one of the first node or the second based on a PRS identifier (PRS-ID) or a scrambling code associated with the PRS.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining the positioning metric based on one or more of a detected arrival time of the PRS, a propagation time, a relay delay, or any combination thereof.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a first candidate positioning metric based on a first hypothesis that the PRS is received from the first node, determining a second candidate positioning metric based on a second hypothesis that the PRS is received from the second node, and selecting one of the first candidate positioning metric and the second candidate positioning metric as the positioning metric based on an outlier rejection scheme.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a first pair of candidate positioning metrics based on a first hypothesis that the PRS is received from the first node, determining a second pair of candidate positioning metrics based on a second hypothesis that the PRS is received from the second node, and selecting one of the first pair of candidate positioning metrics and the second pair of candidate positioning metrics as the positioning metric based on an outlier rejection scheme, where the positioning metric is an RTT positioning metric.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the positioning metric to the second node or a location server.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a geographic location of the UE based on the positioning metric.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the positioning metric may be a differential measurement.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving an indication to avoid using the first and second nodes when generating the differential measurement.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the indication may be an LPP message, an RRC message, a medium access control (MAC) control element (CE), or downlink control information (DCI).

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining to avoid using the first and second nodes when generating the differential measurement based on receiving side information indicating presence of a relay.

A method of wireless communications by a relay node is described. The method may include receiving a transmission time interval (TTI) format indication that indicates that a TTI is either a downlink TTI or an uplink TTI, receiving a transmission for relaying within the TTI, and relaying the transmission during the TTI in accordance with the TTI format indication.

An apparatus for wireless communications by a relay node is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive a TTI format indication that indicates that a TTI is either a downlink TTI or an uplink TTI, to receive a transmission for relaying within the TTI, and to relay the transmission during the TTI in accordance with the TTI format indication.

Another apparatus for wireless communications by a relay node is described. The apparatus may include means for receiving a TTI format indication that indicates that a TTI is either a downlink TTI or an uplink TTI, means for receiving a transmission for relaying within the TTI, and means for relaying the transmission during the TTI in accordance with the TTI format indication.

A non-transitory computer-readable medium storing code for wireless communications by a relay node is described. The code may include instructions executable by a processor to receive a TTI format indication that indicates that a TTI is either a downlink TTI or an uplink TTI, to receive a transmission for relaying within the TTI, and to relay the transmission during the TTI in accordance with the TTI format indication.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a configuration that indicates an uplink amplification level for relaying an uplink transmission from a UE to a base station and a downlink amplification level for relaying a downlink transmission from the base station to the UE, where the transmission is relayed in accordance with the configuration.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, relaying the transmission may include operations, features, means, or instructions for relaying an uplink transmission to the base station in accordance with the uplink amplification level.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, relaying the transmission may include operations, features, means, or instructions for relaying a downlink transmission to the UE in accordance with the downlink amplification level.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for processing the configuration to determine a reference signal configuration, where the transmission is relayed in accordance with the reference signal configuration.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the reference signal configuration may be a channel state information reference signal (CSI-RS) configuration, a synchronization signal block (SSB) configuration, a sounding reference signal (SRS) configuration, a PRS configuration, or any combination thereof.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for processing the configuration to determine a subset of channels of a set of channels to relay, where the transmission is received within a first channel of the subset of channels.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for processing the configuration to determine an uplink power control configuration, where the transmission is transmitted in accordance with the uplink power control configuration.

A method of wireless communications by a location server is described. The method may include transmitting positioning assistance data (e.g., almanac information) that indicates that a first node operates as a relay (e.g., for a base station, a UE, etc.), receiving a positioning metric that is generated based on the positioning assistance data and a PRS, and determining a geographic location of a UE based on the positioning metric.

An apparatus for wireless communications by a location server is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit positioning assistance data (e.g., almanac information) that indicates that a first node operates as a relay (e.g., for a base station, a UE, etc.), to receive a positioning metric that is generated based on the positioning assistance data and a PRS, and to determine a geographic location of a UE based on the positioning metric.

Another apparatus for wireless communications by a location server is described. The apparatus may include means for transmitting positioning assistance data (e.g., almanac information) that indicates that a first node operates as a relay (e.g., for a base station, a UE, etc.), means for receiving a positioning metric that is generated based on the positioning assistance data and a PRS, and means for determining a geographic location of a UE based on the positioning metric.

A non-transitory computer-readable medium storing code for wireless communications by a location server is described. The code may include instructions executable by a processor to transmit positioning assistance data (e.g., almanac information) that indicates that a first node operates as a relay (e.g., for a base station, a UE, etc.), to receive a positioning metric that is generated based on the positioning assistance data and a PRS, and to determine a geographic location of a UE based on the positioning metric.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the PRS is received from the first node based on the positioning assistance data and generating the positioning metric based on determining that the PRS is received from the first node.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the PRS is received from the base station based on the positioning assistance data and generating the positioning metric based on determining that the PRS is received from the second node.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the positioning assistance data indicates one or more of a cell identifier, a UE identifier, a geographic location, or a beam identifier, for the first node, the second node, or both.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the positioning assistance data indicates one or more of an antenna array configuration, an antenna panel configuration, an orientation, or a beam pattern, for the first node, the second node, or both.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the positioning assistance data indicates a backhaul gain between the first and second nodes, an access gain between the first node and the UE, or both.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the positioning assistance data may indicate that the first node is an active relay or a passive relay.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the positioning assistance data may indicate an orientation, attenuation, or both, for at least one angle of incidence for the first node.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the positioning assistance data may indicate delay introduced by the first node when relaying a transmission.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the positioning metric may include a detected time of arrival, an angle of arrival, or both.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for generating the PRS based on a PRS-ID and transmitting the PRS.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for generating the PRS based on a scrambling of the PRS using a scrambling code and transmitting the generated PRS.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a first candidate positioning metric based on a first hypothesis that the PRS is received from the first node, determining a second candidate positioning metric based on a second hypothesis that the PRS is received from the base station, and selecting one of the first candidate positioning metric and the second candidate positioning metric as the positioning metric based on an outlier rejection scheme.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a first pair of candidate positioning metrics based on a first hypothesis that the PRS is received from the first node, determining a second pair of candidate positioning metrics based on a second hypothesis that the PRS is received from the base station, and selecting one of the first pair of candidate positioning metrics and the second pair of candidate positioning metrics as the positioning metric based on an outlier rejection scheme, where the positioning metric is an RTT positioning metric.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a geographic location of the UE based on the positioning metric.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the positioning metric may be a differential measurement.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting an indication to avoid using a reference signal transmitted by the first node or the base station when generating the differential measurement.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the indication may be an LPP message, an RRC message, a MAC-CE, or DCI.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the location server may be co-located with the base station.

A method of wireless communications by a base station is described. The method may include receiving a positioning metric from a UE that is generated based on a PRS and positioning assistance data (e.g., almanac information) that indicates that a first node operates as a relay for the base station and transmitting the positioning metric to a location server.

An apparatus for wireless communications by a base station is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive a positioning metric from a UE that is generated based on a PRS and positioning assistance data (e.g., almanac information) that indicates that a first node operates as a relay for the base station and to transmit the positioning metric to a location server.

Another apparatus for wireless communications by a base station is described. The apparatus may include means for receiving a positioning metric from a UE that is generated based on a PRS and positioning assistance data (e.g., almanac information) that indicates that a first node operates as a relay for the base station and means for transmitting the positioning metric to a location server.

A non-transitory computer-readable medium storing code for wireless communications by a base station is described. The code may include instructions executable by a processor to receive a positioning metric from a UE that is generated based on a PRS and positioning assistance data (e.g., almanac information) that indicates that a first node operates as a relay for the base station and to transmit the positioning metric to a location server.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting an indication to avoid using a second PRS transmitted by the first node or the base station when generating the positioning metric that includes a differential measurement.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the indication may be an LPP message, an RRC message, a MAC-CE, or DCI.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the base station may be co-located with the location server.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the PRS.

