Per-cell timing and/or frequency acquisition and their use on channel estimation in wireless networks

• US 10,111,111 B2
• Filed: 11/18/2010
• Issued: 10/23/2018
• Est. Priority Date: 11/19/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Yoo, Taesang, Luo, Tao, Zhang, Xiaoxia, Liu, Ke
• Primary Examiner(s): Chen, Peter
• Application Number:
  US12/949,020
• Publication Number:
  US 20110286376A1
• Time in Patent Office: 2,896 Days
• Field of Search: 370330, 370350, 4554521
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 56/0035 detecting errors in frequency or phase

Abstract

A method, an apparatus, and a computer program product for wireless communication are provided in which a system timing is estimated, derived from timing of one or more cells, a timing offset is determined for a plurality of cells relative to the estimated system timing, and signals received form the plurality of cells are processed using the timing offsets. In addition, a method, an apparatus, and a computer program product for wireless communication are provided in which a carrier frequency is estimated, derived from a frequency of one or more cells, a frequency offset is determined for a plurality of cells relative to the estimated system timing, and signals received form the plurality of cells are processed using the frequency offsets.

Claims

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

connecting to a serving cell having a weaker receive signal strength for one or more reference signals as compared to one or more non-serving cells;

receiving signals from a plurality of the non-serving cells;

estimating system timing, wherein the estimated system timing is derived, at least, from the received signals from the plurality of the non-serving cells;

determining a plurality of timing offsets, relative to the estimated system timing, for a plurality of cells including the serving cell and at least one of the plurality of non-serving cells; and

processing signals received from the plurality of cells with channel tap truncation windows set based on the timing offsets.

2. The method of claim 1, wherein the estimating the timing is performed by using a received signal comprising at least one of a cell-specific reference signal, a primary synchronization signal, a secondary synchronization signal, or a cyclic prefix.

3. The method of claim 2, wherein the received signal comprises a signal received from a particular cell.

4. The method of claim 3, wherein the particular cell comprises a cell with a strongest received signal strength for one or more reference signals.

5. The method of claim 2, wherein the received signal comprises a combination of signals from multiple cells.

6. The method of claim 1, wherein all or a subset of the plurality of cells are configured to participate in cooperative multi-point (CoMP) transmissions to the UE.

7. The method of claim 6, wherein the processing comprises:

determining an average timing offset from one or more of the determined timing offsets; and

setting a channel tap truncation window based on the average timing offset.

8. The method of claim 7, wherein:

determining the average timing offset comprises utilizing timing offsets for cells participating in CoMP transmissions.

9. The method of claim 7, wherein:

determining the average timing offset comprises excluding timing offsets for one or more cells not participating in CoMP transmissions.

10. The method of claim 7, wherein:

determining the average timing offset comprises calculating a weighted average according to received signal strengths.

11. The method of claim 1, wherein the estimated system timing is based on the timings of a plurality of non-serving cells.

12. An apparatus for wireless communication, comprising:

means for connecting to a serving cell having a weaker receive signal strength for one or more reference signals as compared to one or more non-serving cells;

means for receiving signals from a plurality of the non-serving cells;

means for estimating system timing, wherein the estimated system timing is derived, at least, from the received signals from the plurality of the non-serving cells;

means for determining a plurality of timing offsets, relative to the estimated system timing, for a plurality of cells including the serving cell and at least one of the plurality of non-serving cells; and

means for processing signals received from the plurality of cells with channel tap truncation windows set based on the timing offsets.

13. The apparatus of claim 12, wherein the means for estimating utilizes a received signal comprising at least one of a cell-specific reference signal, a primary synchronization signal, a secondary synchronization signal, or a cyclic prefix.

14. The apparatus of claim 13, wherein the received signal comprises a signal received from a particular cell.

15. The apparatus of claim 14, wherein the particular cell comprises a cell with a strongest received signal strength for one or more reference signals.

16. The apparatus of claim 13, wherein the received signal comprises a combination of signals from multiple cells.

17. The apparatus of claim 12, wherein all or a subset of the plurality of cells are configured to participate in cooperative multi-point (CoMP) transmissions to the UE.

18. The apparatus of claim 17, wherein the means for processing comprises:

means for determining an average timing offset from one or more of the determined timing offsets; and

means for setting a channel tap truncation window based on the average timing offset.

19. The apparatus of claim 18, wherein:

the means for determining the average timing offset comprises means for utilizing timing offsets for cells participating in CoMP transmissions.

20. The apparatus of claim 18, wherein:

the means for determining the average timing offset comprises means for excluding timing offsets for one or more cells not participating in CoMP transmissions.

21. The apparatus of claim 18, wherein:

the means for determining the average timing offset comprises means for calculating a weighted average according to received signal strengths.

22. An apparatus for wireless communications, comprising:

at least one processor configured to,

connect to a serving cell having a weaker receive signal strength for one or more reference signals as compared to one or more non-serving cells;

receive signals from a plurality of the non-serving cells,

estimate system timing, wherein the estimated system timing is derived, at least, from the received signals from the plurality of the non-serving cells

determine a plurality of timing offsets, relative to the estimated system timing, for a plurality of cells including the serving cell and at least one of the plurality of non-serving cells, and

process signals received from the plurality of cells with channel tap truncation windows set based on the timing offsets; and

a memory coupled with the at least one processor.

23. A non-transitory computer-readable storage medium having a set of instructions stored thereon, executable by a processor for:

connecting to a serving cell having a weaker receive signal strength for one or more reference signals as compared to one or more non-serving cells;

receiving signals from a plurality of the non-serving cells;

estimating system timing, wherein the estimated system timing is derived, at least, from the received signals from the plurality of the non-serving cells;

determining a plurality of timing offsets, relative to the estimated system timing, for a plurality of cells including the serving cell and at least one of the plurality of non-serving cells; and

processing signals received from the plurality of cells with channel tap truncation windows set based on the timing offsets.