HANDLING OF RADIO FREQUENCY FRONT-END GROUP DELAYS FOR ROUND TRIP TIME ESTIMATION

• US 20200137607A1
• Filed: 10/28/2019
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: AKKARAKARAN, Sony, LUO, Tao, SORIAGA, Joseph Binamira, MANOLAKOS, Alexandros, BHUSHAN, Naga, OPSHAUG, Guttorm Ringstad, FISCHER, Sven
• Granted Patent: US 11,159,972 B2
• Time in Patent Office: Days
• CPC Class Codes: G01S 5/012 Identifying whether indoors or outdoors
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0215 Interference
• CPC Class Codes: G01S 5/0218 Multipath in signal reception
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 56/009 Closed loop measurements
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/51 based on terminal or device properties

Abstract

Disclosed are techniques for handling of radio frequency (RF) front-end group delays for round trip time (RTT) estimation. In an aspect, a network entity determines a network total group delay (GD) and a user equipment (UE) determines a UE total GD. The network entity transmits one or more RTT measurement (RTTM) signals to the UE. Each RTTM signal includes a RTTM waveform. The UE determines one or more one or more RTT response (RTTR) payloads for one or more RTTR signals. Each RTTR signal also includes a RTTR waveform. The UE transmits the RTTR signal(s) to the network entity. For each RTTR signal, a transmission time of the RTTR waveform and/or the RTTR payload is/are determined based on the UE total GD. The network entity determines a RTT between the UE and the network entity based on the RTTM signal(s), the RTTR signal(s), and the network total GD.

Claims

1. A method of a network entity, the method comprising:

determining a network total group delay (GD) comprising a network transmission GD and a network reception GD,

the network transmission GD indicating a time interval between a measured transmission time of a network Tx signal transmitted from the network entity and an actual transmission time of the network Tx signal leaving the network entity, and

the network reception GD indicating a time interval between an actual arrival time of a network Rx signal at the network entity and a measured arrival time of the network Rx signal at the network entity;

transmitting, to a user equipment (UE), one or more round trip time (RTT) measurement (RTTM) signals on RTTM resources comprising downlink (DL) physical layer resources, each RTTM signal comprising an RTTM waveform;

receiving, from the UE, one or more RTT response (RTTR) signals on RTTR resources comprising uplink (UL) physical layer resources, each RTTR signal corresponding to one or more of the transmitted RTTM signals and comprising an RTTR waveform and an RTTR payload; and

determining an RTT between the UE and the network entity based on the RTTM signal(s), the RTTR signal(s), and the network total GD.

2. The method of claim 1, wherein the network entity is a network node or a core network entity.

3. The method of claim 1, wherein determining the network total GD comprises:

scheduling self-transmit and self-receive resources respectively for transmit and receive antennas of the network entity, the self-transmit and self-receive resources comprising physical layer resources, and the transmit and receive antennas being different antennas;

transmitting a test signal from the transmit antenna on the self-transmit resource at transmit time tt, the transmit time tt being a time in a digital domain and corresponding to a frame, subframe, or a slot of the self-transmit resource in which symbols of the test signal are scheduled for transmission;

listening on the receive antenna on the self-receive resource and detecting the reception of the test signal at receive time tr, the receive time being a time in the digital domain and corresponding to a frame, subframe, or a slot of the self-receive resource in which received symbols contained therein are recognized as the symbols of the test signal; and

determining the network total GD based on the transmit time tt and the receive time tr.

4. The method of claim 3, wherein multiple network total GDs are determined, each network total GD corresponding to any combination of the following:

one or more transmit antennas of the network entity, one or more receive antennas of the network entity, one or more modulation and coding schemes (MCSs), and/or one or more operating frequencies.

5. The method of claim 1,

wherein the RTTR payload of at least one RTTR signal explicitly includes an actual UE response delay indicating a time interval between an actual RTTM arrival time t2′

and an actual RTTR transmit time t3′

at the UE, and

wherein the RTT is calculated based on the actual UE response delay, the network total GD, and the measured total time.

6. The method of claim 5,

wherein the actual UE response delay includes an actual UE turn-around time (t3′

−

t2′

) and/or an actual UE Rx−

Tx time difference (t2′

−

t3′

),

wherein when the actual UE response delay includes the actual UE turn-around time, the RTT is calculated by subtracting a sum of the actual UE turn-around time and the network total GD from the measured total time, and/or

wherein when the actual UE response delay includes the actual UE Rx−

Tx time difference, the RTT is calculated by subtracting the network total GD from a sum of the measured total time and Rx−

Tx time difference.

7. The method of claim 1,

wherein the RTTR payload of at least one RTTR signal explicitly includes a measured UE response delay indicating a time interval between a measured RTTM arrival time t2 and a measured RTTR transmit time t3 at the UE,

wherein the RTTR waveform arrival time of the at least one RTTR signal deviates from an expected arrival time by a deviation amount representing a UE total GD comprising a UE transmission GD and a UE reception GD,

the UE transmission GD indicating a time interval between a measured transmission time of a UE Tx signal transmitted from the UE and an actual transmission time of the UE Tx signal leaving the UE, and

the UE reception GD indicating a time interval between an actual arrival time of a UE Rx signal at the UE and a measured arrival time of the UE Rx signal at the UE, and

wherein the RTT is calculated based on the measured UE response delay, the network total GD, the deviation amount, and the measured total time.

8. The method of claim 7,

wherein the measured UE response delay includes a measured UE turn-around time (t3−

t2) and/or a measured UE Rx−

Tx time difference (t2−

t3),

wherein when the measured UE response delay includes the measured UE turn-around time, the RTT is calculated by subtracting a sum of the measured UE turn-around time, the network total GD, and the deviation amount from the measured total time, and/or

wherein when the actual UE response delay includes the measured UE Rx−

Tx time difference, the RTT is calculated by subtracting a sum of the network total GD and the deviation amount from a sum of the measured total time and the measured Rx−

Tx time difference.

9. The method of claim 1,

wherein the RTTR payload of at least one RTTR signal explicitly includes a measured UE response delay indicating a time interval between a measured RTTM arrival time t2 and a measured RTTR transmit time t3 at the UE and/or explicitly includes a UE total GD comprising a UE transmission GD and a UE reception GD,

the UE transmission GD indicating a time interval between a measured transmission time of a UE Tx signal transmitted from the UE and an actual transmission time of the UE Tx signal leaving the UE, and

the UE reception GD indicating a time interval between an actual arrival time of a UE Rx signal at the UE and a measured arrival time of the UE Rx signal at the UE, and

wherein the RTT is calculated based on the UE response delay, the network total GD, the UE total GD, and the measured total time.

10. The method of claim 9,

wherein the measured UE response delay includes a measured UE turn-around time (t3−

t2) and/or a measured UE Rx−

Tx time difference (t2−

t3),

wherein when the measured UE response delay includes the measured UE turn-around time, the RTT is calculated by subtracting a sum of the measured UE turn-around time, the network total GD, and the UE total GD from the measured total time, and/or

wherein when the actual UE response delay includes the measured UE Rx−

Tx time difference, the RTT is calculated by subtracting a sum of the network total GD and the UE total GD from a sum of the measured total time and the measured Rx−

Tx time difference.

11. The method of claim 9,

wherein when the RTTR payload explicitly includes both the measured UE response delay and the UE reception GD, the measured UE response delay and the UE total GD used in the calculation of the RTT are the measured UE response delay and the UE total GD included in the RTTR payload,

wherein when the RTTR payload explicitly includes the measured UE response delay but does not include the UE reception GD, the measured UE response delay used in the calculation of the RTT is the measured UE response delay included in the RTTR payload and the UE total GD used in the calculation of the RTT is the UE total GD included in a previous RTTR payload, and

wherein when the RTTR payload does not include the measured UE response delay but does explicitly include the UE reception GD, the measured UE response delay used in the calculation of the RTT is the measured UE response delay included in a previous RTTR payload and the UE total GD used in the calculation of the RTT is the UE total GD included in the RTTR payload.

12. The method of claim 1, further comprising:

receiving a UE capability report from the UE, the UE capability report comprising one or more capabilities of the UE including accuracy of group delay measurements and/or capability of making use of calibration gaps to measure group delay dynamically,

wherein a bandwidth of the RTTM waveform is adjusted based on the UE'"'"'s accuracy of group delay measurements.

13. The method of claim 1, further comprising:

receiving a request for scheduling of self-transmit and self-receive resources respectively for transmit and receive antennas of the UE, the self-transmit and self-receive resources comprising physical layer resources, and the transmit and receive antennas being different antennas of the UE;

scheduling the requested self-transmit and self-receive resources for the UE; and

notifying the UE of the scheduled self-transmit and self-receive resources.

14. A method of a user equipment (UE), the method comprising:

determining a UE total group delay (GD) comprising a UE transmission GD and a UE reception GD,

the UE transmission GD indicating a time interval between a measured transmission time of a UE Tx signal transmitted from the UE and an actual transmission time of the UE Tx signal leaving the UE, and

the UE reception GD indicating a time interval between an actual arrival time of a UE Rx signal at the UE and a measured arrival time of the UE Rx signal at the UE;

receiving, from a network entity, one or more round trip time (RTT) measurement (RTTM) signals on RTTM resources comprising downlink (DL) physical layer resources, each RTTM signal comprising an RTTM waveform;

determining one or more RTT response (RTTR) payloads for one or more RTTR signals, each RTTR signal corresponding to one or more of the received RTTM signals and comprising an RTTR waveform and the RTTR payload; and

transmitting, to the network entity, the one or more RTTR signals on RTTR resources comprising uplink (UL) physical layer resources,

wherein for each RTTR signal, a transmission timing of the RTTR waveform is determined based on the UE total GD, or the RTTR payload is determined based on the UE total GD, or both.

15. The method of claim 14, wherein the network entity is a network node or a core network entity.

16. The method of claim 14, wherein determining the UE total GD comprises:

requesting to the network entity scheduling self-transmit and self-receive resources respectively for transmit and receive antennas of the UE, the self-transmit and self-receive resources comprising physical layer resources, and the transmit and receive antennas being different antennas;

transmitting a test signal from the transmit antenna on the self-transmit resource at transmit time tt, the transmit time tt being a time in a digital domain and corresponding to a frame, subframe, or a slot of the self-transmit resource in which symbols of the test signal are scheduled for transmission;

listening on the receive antenna on the self-receive resource and detecting the reception of the test signal at receive time tr, the receive time being a time in the digital domain and corresponding to a frame, subframe, or a slot of the self-receive resource in which received symbols contained therein are recognized as the symbols of the test signal; and

determining the UE total GD based on the transmit time tt and the receive time tr.

17. The method of claim 16, wherein multiple UE total GDs are determined, each UE total GD corresponding to any combination of the following:

one or more transmit antennas of the UE, one or more receive antennas of the UE, one or more modulation and coding schemes (MCSs), and/or one or more operating frequencies.

18. The method of claim 16, wherein the scheduling of the self-transmit and the self-receive resources is requested such that the self-transmit and self-the receive resources for calibration gap and/or rank reduction are scheduled.

19. The method of claim 14, wherein when a transmission timing of at least one RTTR signal does not deviate from a timing advance (TA) commanded by the network entity, the RTTR payload of the at least one RTTR signal explicitly includes an actual UE response delay calculated based on the UE total GD and a measured UE response delay, the actual UE response delay indicating a time interval between an actual RTTM arrival time t2′

and an actual RTTR transmit time t3′

at the UE, and the measured UE response delay indicating a time interval between a measured RTTM arrival time t2 and a measured RTTR transmit time t3 at the UE.

20. The method of claim 19,

wherein the actual UE response delay includes an actual UE turn-around time (t3′

−

t2′

) and/or an actual UE Rx−

Tx time difference (t2′

−

t3′

),

wherein the measured UE response delay includes a measured UE turn-around time (t3−

t2) and/or a measured UE Rx−

Tx time difference (t2−

t3), and

wherein the actual UE turn-around time is calculated by adding the UE total GD to the measured UE turn-around time, and/or the actual UE Rx−

Tx time difference is calculated by subtracting the UE total GD from the measured UE Rx−

Tx time difference.

21. The method of claim 14, wherein when a transmission timing of at least one RTTR signal deviates from a timing advance (TA) commanded by the network entity by a deviation amount representing the UE total GD, the RTTR payload of the at least one RTTR signal explicitly includes a measured UE response delay and/or the UE total GD, the measured UE response delay indicating a time interval between a measured RTTM arrival time t2 and a measured RTTR transmit time t3 at the UE.

22. The method of claim 21, wherein the measured UE response delay includes a measured UE turn-around time (t3−

t2) and/or a measured UE Rx−

Tx time difference (t2−

t3).

23. The method of claim 21, wherein when the transmission timing of the at least one RTTR signal deviates from the TA commanded by the network entity by the deviation amount representing the UE total GD, the RTTR payload of the at least one RTTR signal explicitly includes the measured UE response delay more frequently than the UE total GD.

24. The method of claim 14, further comprising:

reporting (1110) to the network entity a UE capability report comprising one or more capabilities of the UE including accuracy of group delay measurements and/or capability of making use of calibration gaps to measure group delay dynamically.

25. A network entity, comprising:

a communication device, a processor and a memory configured to;

determine a network total group delay (GD) comprising a network transmission GD and a network reception GD,

the network transmission GD indicating a time interval between a measured transmission time of a network Tx signal transmitted from the network entity and an actual transmission time of the network Tx signal leaving the network entity, and

the network reception GD indicating a time interval between an actual arrival time of a network Rx signal at the network entity and a measured arrival time of the network Rx signal at the network entity;

transmit, to a user equipment (UE), one or more round trip time (RTT) measurement (RTTM) signals on RTTM resources comprising downlink (DL) physical layer resources, each RTTM signal comprising an RTTM waveform;

receive, from the UE, one or more RTT response (RTTR) signals on RTTR resources comprising uplink (UL) physical layer resources, each RTTR signal corresponding to one or more of the transmitted RTTM signals and comprising an RTTR waveform and an RTTR payload; and

determine an RTT between the UE and the network entity based on the RTTM signal(s), the RTTR signal(s), and the network total GD.

26. The network entity of claim 25, wherein in determining the network GD, the communication device, the processor and the memory are configured to:

schedule self-transmit and self-receive resources respectively for transmit and receive antennas of the network entity, the self-transmit and self-receive resources comprising physical layer resources, and the transmit and receive antennas being different antennas;

transmit a test signal from the transmit antenna on the self-transmit resource at transmit time tt, the transmit time tt being a time in a digital domain and corresponding to a frame, subframe, or a slot of the self-transmit resource in which symbols of the test signal are scheduled for transmission;

listen on the receive antenna on the self-receive resource and detecting the reception of the test signal at receive time tr, the receive time being a time in the digital domain and corresponding to a frame, subframe, or a slot of the self-receive resource in which received symbols contained therein are recognized as the symbols of the test signal; and

determine the network total GD based on the transmit time tt and the receive time tr.

27. The network entity of claim 25,

wherein the RTTR payload of at least one RTTR signal explicitly includes an actual UE response delay indicating a time interval between an actual RTTM arrival time t2′

and an actual RTTR transmit time t3′

at the UE, and

wherein in determining the RTT, the communication device, the processor and the memory are configured to;

determine a measured RTTM transmit time t1 for each of the one or more transmitted RTTM signals, the measured RTTM transmit time t1 being a time in a digital domain corresponding to a frame, subframe, or a slot of the RTTM resource allocated for the symbols of the RTTM signal;

determine a measured RTTR arrival time t4 for each of the one or more received RTTR signals, the measured RTTR arrival time t4 being a time in the digital domain corresponding to a frame, subframe, or a slot of the RTTR resource containing the symbols of the RTTR signal;

determine a measured total time as (t4−

t1); and

calculate the RTT based on the actual UE response delay, the network total GD, and the measured total time.

28. The network entity of claim 25,

wherein the RTTR payload of at least one RTTR signal explicitly includes a measured UE response delay indicating a time interval between a measured RTTM arrival time t2 and a measured RTTR transmit time t3 at the UE,

wherein the RTTR waveform arrival time of the at least one RTTR signal deviates from an expected arrival time by the deviation amount representing a UE total GD comprising a UE transmission GD and a UE reception GD,

the UE transmission GD indicating a time interval between a measured transmission time of a UE Tx signal transmitted from the UE and an actual transmission time of the UE Tx signal leaving the UE, and

the UE reception GD indicating a time interval between an actual arrival time of a UE Rx signal at the UE and a measured arrival time of the UE Rx signal at the UE, and

wherein in determining the RTT, the communication device, the processor and the memory are configured to:

determine a measured RTTM transmit time t1 for each of the one or more transmitted RTTM signals, the measured RTTM transmit time t1 being a time in a digital domain corresponding to a frame, subframe, or a slot of the RTTM resource allocated for the symbols of the RTTM signal;

determine a measured RTTR arrival time t4 for each of the one or more received RTTR signals, the measured RTTR arrival time t4 being a time in the digital domain corresponding to a frame, subframe, or a slot of the RTTR resource containing the symbols of the RTTR signal;

determine a measured total time as (t4−

t1); and

calculate RTT based on the measured UE response delay, the network total GD, and the deviation amount from the measured total time.

29. The network entity of claim 25,

wherein the RTTR payload of at least one RTTR signal explicitly includes a measured UE response delay indicating a time interval between a measured RTTM arrival time t2 and/or a UE total GD comprising a UE transmission GD and a UE reception GD,

the UE transmission GD indicating a time interval between a measured transmission time of a UE Tx signal transmitted from the UE and an actual transmission time of the UE Tx signal leaving the UE, and

the UE reception GD indicating a time interval between an actual arrival time of a UE Rx signal at the UE and a measured arrival time of the UE Rx signal at the UE,

wherein in determining the RTT, the communication device, the processor and the memory are configured to:

determine a measured RTTM transmit time t1 for each of the one or more transmitted RTTM signals, the measured RTTM transmit time t1 being a time in a digital domain corresponding to a frame, subframe, or a slot of the RTTM resource allocated for the symbols of the RTTM signal;

determine a measured RTTR arrival time t4 for each of the one or more received RTTR signals, the measured RTTR arrival time t4 being a time in the digital domain corresponding to a frame, subframe, or a slot of the RTTR resource containing the symbols of the RTTR signal;

determine a measured total time as (t4−

t1); and

calculate RTT based on the measured UE response delay, the network total GD, the UE total GD, and the measured total time.

30. A user equipment (UE), comprising:

a communication device, a processor and a memory configured to;

determine a UE total group delay (GD) comprising a UE transmission GD and a UE reception GD,

the UE transmission GD indicating a time interval between a measured transmission time of a UE Tx signal transmitted from the UE and an actual transmission time of the UE Tx signal leaving the UE, and

the UE reception GD indicating a time interval between an actual arrival time of a UE Rx signal at the UE and a measured arrival time of the UE Rx signal at the UE;

receive, from a network entity, one or more round trip time (RTT) measurement (RTTM) signals on RTTM resources comprising downlink (DL) physical layer resources, each RTTM signal comprising an RTTM waveform;

determine one or more RTT response (RTTR) payloads for one or more RTTR signals, each RTTR signal corresponding to one or more of the received RTTM signals and comprising an RTTR waveform and the RTTR payload; and

transmit, to the network entity, the one or more RTTR signals on RTTR resources comprising uplink (UL) physical layer resources,

wherein for each RTTR signal, a transmission timing of the RTTR waveform is determined based on the UE total GD, or the RTTR payload is determined based on the UE total GD, or both.

31. The UE of claim 30, wherein determining the UE total GD, the communication device, the processor and the memory are configured to:

request to the network entity scheduling self-transmit and self-receive resources respectively for transmit and receive antennas of the UE, the self-transmit and self-receive resources comprising physical layer resources, and the transmit and receive antennas being different antennas;

transmit a test signal from the transmit antenna on the self-transmit resource at transmit time tt, the transmit time tt being a time in a digital domain and corresponding to a frame, subframe, or a slot of the self-transmit resource in which symbols of the test signal are scheduled for transmission;

listen on the receive antenna on the self-receive resource and detecting the reception of the test signal at receive time tr, the receive time being a time in the digital domain and corresponding to a frame, subframe, or a slot of the self-receive resource in which received symbols contained therein are recognized as the symbols of the test signal; and

determine the UE total GD based on the transmit time tt and the receive time tr.

32. The UE of claim 30,

wherein when a transmission timing of at least one RTTR signal does not deviate from a timing advance (TA) commanded by the network entity, the RTTR payload of the at least one RTTR signal explicitly includes an actual UE response delay calculated based on the UE total GD and a measured UE response delay, the actual UE response delay indicating a time interval between an actual RTTM arrival time t2′

and an actual RTTR transmit time t3′

at the UE, and the measured UE response delay indicating a time interval between a measured RTTM arrival time t2 and a measured RTTR transmit time t3 at the UE,

wherein the actual UE response delay includes an actual UE turn-around time (t3′

−

t2′

) and/or an actual UE Rx−

Tx time difference (t2′

−

t3′

),

wherein the measured UE response delay includes a measured UE turn-around time (t3−

t2) and/or a measured UE Rx−

Tx time difference (t2−

t3), and

wherein the communication device, the processor and the memory are configured to;

calculate the actual UE turn-around time by adding the UE total GD to the measured UE turn-around time, and/or

calculate the actual UE Rx−

Tx time difference by subtracting the UE total GD from the measured UE Rx−

Tx time difference.

33. The UE of claim 30,

wherein when a transmission timing of at least one RTTR signal deviates from a timing advance (TA) commanded by the network entity by a deviation amount representing the UE total GD, the RTTR payload of the at least one RTTR signal explicitly includes a measured UE response delay and/or the UE total GD, the measured UE response delay indicating a time interval between a measured RTTM arrival time t2 and a measured RTTR transmit time t3 at the UE, and

wherein the measured UE response delay includes a measured UE turn-around time (t3−

t2) and/or a measured UE Rx−

Tx time difference (t2−

t3).

34. The method of claim 33, wherein when the transmission timing of the at least one RTTR signal deviates from the TA commanded by the network entity by the deviation amount representing the UE total GD, the RTTR payload of the at least one RTTR signal explicitly includes the measured UE response delay more frequently than the UE total GD.