Granted Patent B2

US 11,985,618 · App. 17/420,127 · Granted May 14, 2024

Inventors: Murali Narasimha (Lake Oswego, OR); Youn Hyoung Heo (San Jose, CA); Yujian Zhang (Beijing, CN)

Assignee: Apple Inc.

H04W56/0045H04B7/18513H04W48/10H04W56/0065H04W74/0833

Abstract

Claims (38)

1. A method of wireless communication by a user equipment (UE), the method comprising:

obtaining a timing advance value for the wireless communication with a satellite base station, wherein the obtaining the timing advance value includes receiving the timing advance value in a broadcast system information message;

determining a transmission time for transmission of a random access channel (RACH) preamble based on the timing advance value;

transmitting the RACH preamble at the transmission time;

receiving a response to the transmitted RACH preamble; and

determining a correction to the timing advance value, wherein the correction is based on an altitude of the UE and wherein the determining the transmission time further includes applying the correction to the received timing advance value.

2. The method of claim 1 , wherein the receiving the timing advance value includes receiving the timing advance value in a system information block.

3. The method of claim 1 , further comprising:

receiving a reference altitude associated with the received timing advance value, and

wherein the determining the correction to the timing advance value further includes using the reference altitude.

4. The method of claim 1 , further comprising:

determining an indication of a subframe for a RACH occasion, and

wherein the transmission time is earlier than the subframe by a time period equal to the timing advance value.

5. The method of claim 1 , wherein the obtaining the timing advance value comprises:

estimating a propagation delay between the UE and the satellite base station;

and determining the timing advance value based on the estimated propagation delay.

6. The method of claim 5 , wherein the estimating the propagation delay includes using a synchronized clock.

7. The method of claim 5 , wherein the estimating the propagation delay includes:

receiving a downlink message from the satellite base station, the downlink message having a timestamp according to a synchronized clock; and

estimating the propagation delay based on a difference between the timestamp and a reception time when the downlink message is received by the UE.

8. The method of claim 5 , wherein the estimating the propagation delay includes using a location of the UE.

9. The method of claim 5 , wherein the estimating the propagation delay includes using location coordinates of the satellite base station.

10. The method of claim 9 , further comprising:

receiving the location coordinates via broadcast signaling.

11. The method of claim 1 , wherein the satellite base station is a next generation base station (gNB).

12. A user equipment (UE) for wireless communication, the UE comprising:

processor circuitry configured to:

receive a timing advance value for the wireless communication with a satellite base station in a broadcast system information message from the satellite base station;

determine a transmission time for transmission of a random access channel (RACH) preamble based on the timing advance value; and

determine a correction to the timing advance value, wherein the correction is based on an altitude of the UE and wherein the processing circuitry is configured to determine the transmission time by using the correction to the timing advance value; and

radio front end circuitry configured to transmit the RACH preamble at the transmission time,

wherein the processor circuitry is further configured to receive a response to the transmitted RACH preamble.

13. The UE of claim 12 , wherein the processor circuitry is further configured to:

receive a reference altitude associated with the timing advance value, and

determine the correction to the timing advance value based on the reference altitude.

14. The UE of claim 12 , wherein the processor circuitry is further configured to:

estimate a propagation delay between the UE and the satellite base station; and

determine the correction to the timing advance value based on the estimated propagation delay.

Continuity (2)

Cited By (8)

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