Apparatus and method for communicating and processing a reference signal based on an identifier associated with a base station

• US 8,396,047 B2
• Filed: 03/03/2011
• Issued: 03/12/2013
• Est. Priority Date: 02/03/2009
• Status: Active Grant

• Current Assignee: Motorola Mobility LLC (Lenovo Group Ltd.)
• Original Assignee: Motorola Mobility LLC (Lenovo Group Ltd.)
• Inventors: Krishnamurthy, Sandeep H., Love, Robert T., Nimbalker, Ajit, Stewart, Kenneth A., Zhuang, Xiangyang
• Primary Examiner(s): Cumming, William D
• Application Number:
  US13/040,109
• Publication Number:
  US 20110149868A1
• Time in Patent Office: 740 Days
• Field of Search: 370/344, 370/328
• US Class Current: 370/344
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0091 Signaling for the administration of the divided path

Abstract

A wireless communication device receives at least a section of a subframe from a base station in a wireless communication system. The subframe includes transmission resources multiplexed onto subcarriers of orthogonal frequency division multiplexed (OFDM) symbols. A first set of OFDM symbols includes a reference signal and at least a second set of OFDM symbols includes information other than the reference signal (e.g., channel-coded data). The wireless device determines which OFDM symbols of the subframe constitute the first set of OFDM symbols based on an identifier associated with a base station that transmitted the subframe. The wireless device may then process the reference signal from the OFDM symbols that are determined to be the first set of OFDM symbols. The wireless device may also determine which OFDM symbols of the subframe constitute the second set of OFDM symbols and process non-reference signal information from OFDM symbols of the second set.

Claims

1. A method for a wireless communication device to process a subframe of orthogonal frequency division multiplexed (OFDM) symbols transmitted by any one of a plurality of base stations in a wireless communication system, the method comprising:

receiving at least a section of the subframe, the subframe including a plurality of transmission resources multiplexed onto subcarriers of a plurality of OFDM symbols such that a first set of OFDM symbols includes a reference signal and at least a second set of OFDM symbols includes information other than the reference signal;

determining which OFDM symbols of the subframe constitute the first set of OFDM symbols based on an identifier associated with a base station that transmitted the subframe; and

processing the reference signal from OFDM symbols that are determined to be the first set of OFDM symbols.

2. The method of claim 1, wherein each transmission resource of the plurality of transmission resources occupies a predetermined amount of time on a respective one of the subcarriers, wherein a first set of the plurality of transmission resources is arranged into the first set of OFDM symbols, wherein at least a second set of the plurality of transmission resources is arranged into the second set of OFDM symbols, the second set of transmission resources being different than the first set of transmission resources, and wherein determining which OFDM symbols of the subframe constitute the first set of OFDM symbols comprises:

determining, based on the identifier associated with the base station, which transmission resources of the subframe constitute the first set of transmission resources.

3. The method of claim 2, wherein the plurality of transmission resources includes a third set of transmission resources through which at least one of control information, synchronization information, and one or more additional reference signals was transmitted, the third set of transmission resources being different than the first set of transmission resources and the second set of transmission resources, the method further comprising:

determining which transmission resources of the subframe constitute the third set of transmission resources; and

processing transmission resources determined to be the third set of transmission resources to recover the at least one of control information, synchronization information, and one or more additional reference signals.

4. The method of claim 3, wherein the at least one of control information, synchronization information, and one or more additional reference signals includes at least one of a physical downlink control channel (PDDCH), a physical control format indicator channel (PCFICH), a physical hybrid automatic repeat request indicator channel (PHICH), a broadcast channel, a synchronization channel, a cell-specific reference signal, and a user equipment (UE) specific reference signal.

5. The method of claim 1, wherein the identifier is derived from at least one of an offset identifier, a cell site identifier, a physical cell identifier, a global cell identifier, a symbol index, a slot index, a subframe index, a system frame number, and a radio network transaction identifier.

6. The method of claim 5, wherein the offset identifier is used to derive a starting point offset for extracting a subsequence of a reference quadrature phase shift keying (QPSK) sequence.

7. The method of claim 1, wherein a first set of the plurality of transmission resources is arranged into the first set of OFDM symbols, wherein at least a second set of the plurality of transmission resources is arranged into the second set of OFDM symbols, and wherein the second set of transmission resources includes channel-coded data, the method further comprising:

determining which transmission resources of the second set of transmission resources includes the channel-coded data; and

processing transmission resources that are determined to include the channel-coded data to recover the channel-coded data from the subframe.

8. The method of claim 7, wherein at least a portion of the subframe was transmitted according to one of transmit diversity, open loop spatial multiplexing, and closed loop spatial multiplexing.

9. The method of claim 1, wherein the reference signal is a positioning reference signal.

10. The method of claim 1, further comprising:

receiving the identifier associated with the base station from a second base station prior to receipt of the subframe.

11. The method of claim 1, further comprising:

receiving the identifier associated with the base station from the base station prior to receipt of the subframe.

12. The method of claim 1, wherein the subframe is one of a plurality of subframes transmitted by the base station, the method further comprising:

determining whether the subframe includes the reference signal based on an indication from at least one of the base station and a second base station.

13. The method of claim 1, wherein transmission resources carrying the reference signal were arranged into the first set of OFDM symbols according to at least one of a predetermined allocation, broadcast messaging, user-specific messaging, dynamic allocation, and higher layer signaling.

14. A method for a wireless communication device to process a subframe of orthogonal frequency division multiplexed (OFDM) symbols transmitted by any one of a plurality of base stations in a wireless communication system, the method comprising:

receiving at least a section of the subframe, the subframe including a plurality of transmission resources multiplexed onto subcarriers of a plurality of OFDM symbols, each transmission resource of the plurality of transmission resources occupying a predetermined amount of time on a respective one of the subcarriers, the plurality of transmission resources being arranged into at least a first set of transmission resources that includes a reference signal and a second set of transmission resources that includes channel-coded data, the first set of transmission resources having been multiplexed into a first set of OFDM symbols and the second set of transmission resources having been multiplexed into a second set of OFDM symbols, the first set of OFDM symbols being different from the second set of OFDM symbols; and

determining which OFDM symbols of the subframe constitute the first set of OFDM symbols based on an identifier associated with a base station that transmitted the subframe.

15. The method of claim 14, further comprising:

processing the reference signal from OFDM symbols that are determined to be in the first set of OFDM symbols.

16. The method of claim 14, further comprising:

determining which OFDM symbols of the subframe constitute the second set of OFDM symbols; and

processing the second set of OFDM symbols to recover the channel-coded data from the sub frame.

17. The method of claim 14, wherein at least a portion of the subframe was transmitted according to one of transmit diversity, open loop spatial multiplexing, and closed loop spatial multiplexing.

18. A wireless communication device operable in a wireless communication system that includes at least one base station, the wireless communication device comprising:

a receiver operable to receive at least a section of a subframe from a base station, the subframe including a plurality of transmission resources multiplexed onto subcarriers of a plurality of orthogonal frequency division multiplexed (OFDM) symbols such that a first set of OFDM symbols includes a reference signal and at least a second set of OFDM symbols includes information other than the reference signal; and

a processor operably coupled to the receiver, the processor operable to;

determine which OFDM symbols of the subframe constitute the first set of OFDM symbols based on an identifier associated with the base station; and

process the reference signal from OFDM symbols that are determined to be the first set of OFDM symbols.

19. The wireless communication device of claim 18, wherein each transmission resource of the plurality of transmission resources occupies a predetermined amount of time on a respective one of the subcarriers, wherein a first set of the plurality of transmission resources is arranged into the first set of OFDM symbols, wherein at least a second set of the plurality of transmission resources is arranged into the second set of OFDM symbols, the second set of transmission resources being different than the first set of transmission resources, and wherein the processor is further operable to:

determine, based on the identifier associated with the base station, which transmission resources of the subframe constitute the first set of transmission resources.

20. The wireless communication device of claim 18, wherein the identifier is derived from at least one of an offset identifier, a cell site identifier, a physical cell identifier, a global cell identifier, a symbol index, a slot index, a subframe index, a system frame number, and a radio network transaction identifier.

21. The wireless communication device of claim 20, wherein the offset identifier is used to derive a starting point offset for extracting a subsequence of a reference quadrature phase shift keying (QPSK) sequence.

22. The wireless communication device of claim 18, wherein a first set of the plurality of transmission resources is arranged into the first set of OFDM symbols, wherein at least a second set of the plurality of transmission resources is arranged into the second set of OFDM symbols, wherein the second set of transmission resources includes channel-coded data, and wherein the processor is further operable to:

determine which transmission resources of the second set of transmission resources includes the channel-coded data; and

process transmission resources that are determined to include the channel-coded data to recover the channel-coded data from the subframe.

23. The wireless communication device of claim 22, wherein at least a portion of the subframe was transmitted according to one of transmit diversity, open loop spatial multiplexing, and closed loop spatial multiplexing.

24. The wireless communication device of claim 18, wherein the reference signal is a positioning reference signal.

25. The wireless communication device of claim 18, wherein the receiver is further operable to:

receive the identifier associated with the base station from a second base station prior to receipt of the subframe.

26. The wireless communication device of claim 18, wherein the receiver is further operable to:

receive the identifier associated with the base station from the base station prior to receipt of the subframe.

27. The wireless communication device of claim 18, wherein the subframe is one of a plurality of subframes transmitted by the base station and wherein the processor is further operable to:

determine whether the subframe includes the reference signal based on an indication from at least one of the base station and a second base station.

28. The wireless communication device of claim 18, wherein the plurality of transmission resources includes at least a third set of transmission resources through which at least one of control information, synchronization information, and one or more additional reference signals was transmitted, the third set of transmission resources being different than the first set of transmission resources and the second set of transmission resources, the processor being further operable to:

determine which transmission resources of the subframe constitute the third set of transmission resources; and

process transmission resources determined to be the third set of transmission resources to recover the at least one of control information, synchronization information, and one or more additional reference signals.

29. The wireless communication device of claim 28, wherein the at least one of control information, synchronization information, and one or more additional reference signals includes at least one of a physical downlink control channel (PDDCH), a physical control format indicator channel (PCFICH), a physical hybrid automatic repeat request indicator channel (PHICH), a broadcast channel, a synchronization channel, a cell-specific reference signal, and a user equipment (UE) specific reference signal.