Synchronizing a base station in a wireless communication system

• US 9,001,742 B2
• Filed: 11/15/2013
• Issued: 04/07/2015
• Est. Priority Date: 09/19/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Palanki, Ravi, Agashe, Parag Arun, Gupta, Vikram, Gupta, Rajarshi, Bhushan, Naga
• Primary Examiner(s): Ghowrwal, Omar
• Assistant Examiner(s): BROCKMAN, ANGEL T
• Application Number:
  US14/081,893
• Publication Number:
  US 20140071897A1
• Time in Patent Office: 508 Days
• Field of Search: 370/328, 370/254
• US Class Current: 370/328
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others

Abstract

A method for synchronizing a wireless communication system is disclosed. A silence duration for a base station is determined based on the time required for a neighbor base station to obtain or maintain synchronization. All transmissions from the base station are ceased for the silence duration. Multiple base stations level may cease transmissions at the same time, thus mitigating interference.

Claims

1. A method for synchronizing a wireless communication system, comprising:

determining a stratum level of a base station, the stratum level corresponding to a number of base stations including a global timing source node and zero or more_intermediate base stations between the base station and the global timing source node; and

monitoring for signals from at least one of a neighbor base station or the global timing source node during a time duration determined at least, in part, by the stratum level;

receiving a network-wide global time from at least one neighbor base station or the global timing source node during the time duration.

2. The method of claim 1, wherein the monitoring comprises ceasing all transmissions for the time duration.

3. The method of claim 1, the wherein the monitoring occurs periodically every tracking period in the wireless communication system.

4. The method of claim 1, wherein the base station is a synchronous base station.

5. The method of claim 1, wherein the length of the time duration is based on the stratum level of the base station.

6. The method of claim 5, wherein the time duration is of length n*T where n is the stratum level of the synchronous base station and T is the time required for a neighbor base station to obtain or maintain synchronization.

7. The method of claim 1, wherein the time duration is further based on a maximum error between a network-wide global time and an estimated network-wide time.

8. The method of claim 7, further comprising determining a starting time for the time duration based on the estimated network-wide time and the maximum error between the network-wide global time and the estimated network-wide time.

9. The method of claim 7, further comprising receiving the estimated network-wide time using a backhaul protocol.

10. The method of claim 1, wherein the base station is a pico base station, a femto base station, or a Home eNodeB.

11. The method of claim 1, wherein determining the stratum level comprises receiving one or more synchronization signals and using a synchronization signal that provides a smallest stratum level.

12. The method of claim 11, wherein the synchronization signal used has the highest Signal to Interference and Noise Ratio (SINR) if a plurality of the one or more synchronization signals provide a same stratum level.

13. The method of claim 1, wherein the time duration comprises a plurality of continguous silence durations.

14. The method of claim 1, wherein the time duration comprises a plurality of non-continguous silence durations.

15. An apparatus for synchronizing a wireless communication system, comprising:

a processor;

memory in electronic communication with the processor and containing instructions executable by the processor to;

determine a stratum level of a base station, the stratum level corresponding to a number of base stations including a global timing source node and zero or more intermediate base stations between the base station and the global timing source node; and

monitor for signals from at least one of a neighbor base station or the global timing source node during a time duration determined at least, in part, by the stratum level;

receive a network-wide global time from at least one of a neighbor base station or the global timing source node during the time duration.

16. The apparatus of claim 15, wherein the base station is a pico base station, a femto base station, or a Home eNodeB.

17. The apparatus of claim 15, wherein determining the stratum level comprises receiving one or more synchronization signals and using a synchronization signal that provides a smallest stratum level.

18. The apparatus of claim 17, wherein the synchronization signal used has the highest Signal to Interference and Noise Ratio (SINR) a a plurality of the one or more synchronization signals provide a same stratum level.

19. An apparatus for synchronizing a wireless communication system, comprising:

means for determining a stratum level of a base station, the stratum level corresponding to a number of base stations including a global timing source node and zero or more_intermediate base stations between the base station and the global timing source node; and

means for monitoring for signals from at least one of a neighbor base station or the global timing source node during a time duration determined at least, in part, by the stratum level;

means for receiving a network-wide global time from at least one of a neighbor base station or the global timing source node during the time duration.

20. A computer-program product for synchronizing a wireless communication system, the computer-program product comprising a non-transitory computer-readable medium having instructions thereon, the instructions comprising code for causing a computer to perform the steps of:

determining a stratum level of a base station, the stratum level corresponding to a number of base stations including a global timing source node and zero or more_intermediate base stations between the base station and the global timing source node; and

monitoring for signals from at least one of a neighbor base station or the global timing source node during a time duration determined at least, in part, by the stratum level;

receiving a network-wide global time from at least one of a neighbor base station or the global timing source node during the time duration.