Method and apparatus for reference signal selection in a cellular system

• US 20060009227A1
• Filed: 06/13/2005
• Published: 01/12/2006
• Est. Priority Date: 07/12/2004
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Baum, Kevin L., Vook, Frederick W., Cudak, Mark C.
• Granted Patent: US 7,643,832 B2
• Time in Patent Office: Days
• US Class Current: 455/450
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/2656 Frame synchronisation, e.g. packet synchronisation, time division duplex [TDD] switching point detection or subframe synchronisation
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04W 16/06 Hybrid resource partitioning, e.g. channel borrowing
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00

Abstract

In a wireless communication system, a method and apparatus for reference signal selection is disclosed. In accordance with the preferred embodiment of the present invention, a first reference signal in a first cell is pseudo-randomly selected from a predetermined limited set of reference signals for transmission on a first channel resource. A second reference signal in the cell is pseudo-randomly selected from the predetermined limited set of reference signals for transmission on a second channel resource, where the predetermined limited set of reference signals is common among the first cell and at least a second cell.

Claims

1. A method for selecting a reference signal to be transmitted by a cell of a multi-cell wireless communication system, the method comprising the steps of:

selecting, by the cell, a first reference signal used to identify the cell from a predetermined limited set of reference signals for transmission on a first channel resource;

transmitting the first reference signal on the first channel resource;

selecting, by the cell, a second reference signal used to identify the cell from the predetermined limited set of reference signals for transmission on a second channel resource; and

transmitting the second reference signal on the second channel resource.

2. The method of claim 1 wherein the steps of selecting comprise the steps of pseudo-randomly selecting.

3. The method of claim 2 wherein the step of pseudo-randomly selecting comprises the step of pseudo-randomly selecting based on a function that is initialized with a value that is unique to the cell.

4. The method of claim 2 wherein the step of pseudo-randomly selecting comprises the step of pseudo-randomly selecting based on a function that is initialized with a value that is based on a cell identification value and/or a frame number.

5. The method of claim 1 wherein the steps of selecting the first and the second reference signals comprise the steps of selecting a first and a second reference signals that are utilized for timing, coherent demodulation, synchronization, channel estimation, or base station identification.

6. The method of claim 1 wherein the steps of selecting the first and the second reference signals comprise the steps of selecting a first and a second reference signals that are shared among at least two cells in the multi-cell wireless communication system.

7. The method of claim 1 wherein the steps of selecting the first and the second reference signals comprise the steps of selecting a first and a second GCL-based reference signal.

8. The method of claim 1 wherein the step of transmitting on the first and the second channel resource comprises the step of transmitting on a first and a second time interval.

9. The method of claim 1 wherein the step of transmitting on the first and the second channel resource comprises the step of transmitting on a first and a second set of sub-carriers

10. A method for selecting a reference signal to be transmitted of a multi-cell wireless communication system, the method comprising the steps of:

at a first time, selecting, a first reference signal from a first set of reference signals for transmission on a first channel resource;

transmitting the first reference signal on the first channel resource;

at a later time, selecting, a second reference signal from a second set of reference signals for transmission on a second channel resource; and

transmitting the second reference signal on the second channel resource.

11. The method of claim 10 wherein the steps of selecting comprise the steps of pseudo-randomly selecting.

12. The method of claim 10 wherein the steps of selecting the first and the second reference signals comprise the steps of selecting a first and a second reference signals that are utilized for timing, coherent demodulation, synchronization, channel estimation, or base station identification.

13. The method of claim 10 wherein the steps of selecting the first and the second reference signals comprise the steps of selecting a first and a second reference signals that are shared among at least two cells in the multi-cell wireless communication system.

14. The method of claim 10 wherein the steps of selecting the first and the second reference signals comprise the steps of selecting a first and a second GCL-based reference signal.

15. The method of claim 10 wherein the step of transmitting on the first and the second channel resource comprises the step of transmitting on a first and a second time interval.

16. The method of claim 10 wherein the step of transmitting on the first and the second channel resource comprises the step of transmitting on a first and a second set of sub-carriers

17. An apparatus comprising:

a reference signal selection unit outputting a first reference signal from a predetermined limited set of reference signals for transmission on a first channel resource, and outputting a second reference signal from the predetermined limited set of reference signals for transmission on a second channel resource; and

a transmitter unit transmitting the first reference signal on the first channel resource and transmitting the second reference signal on the second channel resource.

18. The apparatus of claim 17 wherein the reference signal selection unit outputs the first and the second reference signals in a pseudo-random fashion.

19. The apparatus of claim 17 wherein the reference signals are utilized for timing, coherent demodulation, synchronization, channel estimation, or base station identification.

20. The apparatus of claim 17 wherein the first and the second reference signals are shared among at least two cells in a multi-cell wireless communication system.