Propagation delay compensation

1 . A method performed by a user equipment (UE), the method comprising:

the UE receiving a configuration message that comprises positioning reference signal (PRS) resource configuration information defining a PRS resource configuration;

the UE receiving a trigger message transmitted by a base station, the trigger message comprising information for identifying the PRS resource configuration;

after receiving the trigger message, the UE receiving a PRS transmitted by the base station according to the PRS resource configuration;

the UE recording a first time value (T 1 ) indicating the time at which the UE received the PRS;

the UE transmitting a signal to the base station;

the UE recording a second time value (T 2 ) indicating the time at which the UE transmitted the signal; and

the UE calculating either T 1 −T 2 or T 2 −T 1 , wherein

the PRS is a semi-persistently or an a-periodically transmitted downlink (DL) reference signal.

2 . The method of claim 1 , wherein the information included in the trigger message is indicative about to activate and/or de-activate the PRS resource configuration.

3 . The method of claim 2 , wherein after the activation, the PRS is to be received for a configurable time period.

4 . The method of claim 1 , wherein

the PRS resource configuration information is received by means or Radio Resource Control, RRC, signalling, and

the trigger message is a MAC control element (CE).

5 . The method of claim 4 , wherein the MAC CE indicates a serving cell identifier (ID), a TRP ID within the serving cell, and a PRS Resource Set ID within the TRP.

6 . The method of claim 5 , wherein the MAC CE further comprises a bit information indicative if the PRS resource configuration is to be activated or de-activated.

7 . The method of claim 1 , further comprising the UE transmitting the signal to the base station as a result of receiving the trigger message.

8 . The method of claim 7 , wherein

the PRS configuration comprises a pointer to an uplink (UL) configuration, and

the UE transmits the signal to the base station according to the UL configuration.

9 . The method of claim 1 , wherein the UE is configured with the PRS of one transmission and reception point (TRP) only.

10 . The method of claim 9 , wherein the TRP is in the primary serving cell of the UE.

11 . A user equipment (UE), the UE comprising:

a receiver for receiving:

i) a configuration message that comprises positioning reference signal (PRS) resource configuration information defining a PRS resource configuration;

ii) a trigger message transmitted by a base station, the trigger message comprising information for identifying the PRS resource configuration; and

iii) a PRS transmitted by the base station according to the PRS resource configuration, wherein

the PRS is a semi-persistently or an a-periodically transmitted DL reference signal, and

the PRS is transmitted by the base station after the base station transmits the trigger message, and

the UE is configured to:

record a first time value (T 1 ) indicating the time at which the UE received the PRS;

transmit a signal to the base station;

record a second time value (T 2 ) indicating the time at which the UE transmitted the signal; and

calculate either T 1 −T 2 or T 2 −T 1 .

12 . A method performed by a base station, the method comprising:

transmitting to a user equipment (UE) a configuration message that comprises positioning reference signal (PRS) resource configuration information defining a PRS resource configuration;

transmitting to the UE a trigger message, the trigger message comprising information for identifying the PRS resource configuration;

after transmitting the trigger message, transmitting a PRS according to the PRS resource configuration;

recording a first time value, T 1 , indicating the time at which the base station transmitted the PRS;

receiving a signal transmitted by the UE;

recording a second time value, T 2 , indicating the time at which the base station received the signal transmitted by the UE; and

calculating either T 1 −T 2 or T 2 −T 1 , wherein

the PRS is a semi-persistently or an a-periodically transmitted DL reference signal.

13 . The method of claim 12 , wherein the information included in the trigger message is indicative about to activate and/or de-activate the PRS resource configuration.

14 . The method of claim 12 , wherein the resource configuration information comprises an information about a configurable time period to receive the PRS after the activation.

15 . The method of claim 12 , wherein the PRS resource configuration information is received by means or Radio Resource Control (RRC) signalling, and wherein the trigger message is a MAC control element (CE).

16 . The method of claim 15 , wherein the MAC CE indicates a serving cell identifier (ID), a TRP ID within the serving cell, and a PRS Resource Set ID within the TRP.

17 . The method of claim 16 , wherein the MAC CE further comprises a bit indicative if the PRS resource configuration is to be activated or de-activated.

18 . The method of claim 12 , wherein the trigger message triggers the UE to transmit the signal.

19 . The method of claim 18 , wherein the PRS configuration comprises a pointer to an uplink (UL) configuration and the UE is configured to transmit the signal to the base station according to the UL configuration.

20 . A base station, the base station comprising:

memory;

processing circuitry;

a receiver; and

a transmitter, wherein the base station is configured to:

transmit to a user equipment (UE) a configuration message that comprises positioning reference signal (PRS) resource configuration information defining a PRS resource configuration;

transmit to the UE a trigger message, the trigger message comprising information for identifying the PRS resource configuration;

after transmitting the trigger message, transmit a PRS according to the PRS resource configuration;

record a first time value, T 1 , indicating the time at which the base station transmitted the PRS;

record a second time value, T 2 , indicating the time at which the base station received a signal transmitted by the UE; and

calculate either T 1 −T 2 or T 2 −T 1 , wherein

the PRS is a semi-persistently or an a-periodically transmitted DL reference signal.