Use of first and second preambles in wireless communication signals

• US 8,488,634 B2
• Filed: 07/06/2010
• Issued: 07/16/2013
• Est. Priority Date: 07/07/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Novak, Robert, Fong, Mo-Han
• Primary Examiner(s): Pezzlo, John
• Application Number:
  US12/830,976
• Publication Number:
  US 20110075748A1
• Time in Patent Office: 1,106 Days
• Field of Search: 370/252, 370/329, 370/430, 370/509
• US Class Current: 370/509
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/26136 Pilot sequence conveying additional information
• CPC Class Codes: H04W 56/00 Synchronisation arrangements

Abstract

A method and system for a method of transmitting data within a signal frame. The method comprises inserting a first synchronization preamble into a first location within the signal frame and inserting a second synchronization preamble into a second location within the signal frame, wherein the first synchronization preamble conveys information indicative of the second location. The method further comprises issuing the signal frame towards a receiving device in a wireless communication environment.

Claims

1. A method of transmitting data within a signal frame, the method comprising:

a) inserting a first synchronization preamble into a first location within the signal frame;

b) inserting a second synchronization preamble into a second location within the signal frame, wherein the first synchronization preamble conveys information indicative of the second location;

c) issuing the signal frame towards a receiving device in a wireless communication environment.

2. The method as defined in claim 1, wherein the signal frame is a frame of an Orthogonal Frequency Division Multiplexing (OFDM) signal.

3. The method as defined in claim 1, wherein the information indicative of the second location is carried via a first synchronization sequence.

4. The method as defined in claim 3, wherein the first synchronization sequence conveys information indicative of a relative timing between the first preamble and the second preamble.

5. The method as defined in claim 3, wherein the first synchronization sequence conveys information indicative of an offset between the first synchronization preamble and the second synchronization preamble.

6. The method as defined in claim 3, wherein the first synchronization sequence further conveys information indicative of an identification of a group of transmitting devices, the signal frame being issued towards the receiving device by a certain transmitting device belonging to the group of transmitting devices.

7. The method as defined in claim 6, wherein the group of transmitting devices all transmit the first synchronization sequence at a same time.

8. The method as defined in claim 6, wherein the second synchronization preamble conveys information indicative of a local ID of the certain transmitting device belonging to the group of transmitting devices.

9. The method as defined in claim 8, wherein the information indicative of a local ID of the certain transmitting device is carried via a second synchronization sequence.

10. The method as defined in claim 9, wherein a combination of the first synchronization sequence and the second synchronization sequence conveys a cell ID of the certain transmitting device that issues the signal frame towards the receiving device.

11. The method as defined in claim 9, wherein at least one of the first synchronization sequence and the second synchronization sequence conveys control information.

12. The method as defined in claim 6, wherein at least a portion of the first synchronization sequence is indicative that the group of transmitting devices is a group of mobile transmitting devices.

13. The method as defined in claim 3, wherein the first synchronization sequence further conveys information indicative of at least one of a relative timing and a relative position of a broadcast header in relation to the first synchronization preamble.

14. The method as defined in claim 3, wherein the first synchronization sequence further conveys information indicative of at least one of a relative timing and a relative position of a legacy frame in relation to the first synchronization preamble.

15. The method as defined in claim 14, wherein the first synchronization sequence belongs to a first sequence set and the second synchronization sequence belongs to a second sequence set, the first sequence set being smaller than the second sequence set.

16. The method as defined in claim 15, wherein at least one synchronization sequence within the first sequence set is associated with a group of mobile transmitting devices.

17. The method as defined in claim 1, wherein the first synchronization preamble and the second synchronization preamble are transmitted over a carrier frequency, at least one of the first synchronization preamble and the second synchronization preamble being confined to a fixed bandwidth of the carrier frequency.

18. The method as defined in claim 17, wherein the fixed bandwidth has the same bandwidth as the carrier frequency.

19. The method as defined in claim 17, wherein the fixed bandwidth is smaller than a bandwidth of the carrier frequency.

20. The method as defined in claim 19, wherein the fixed bandwidth is aligned with an edge of the carrier frequency.

21. The method as defined in claim 17, wherein the first synchronization preamble and the second synchronization preamble are transmitted over a given one of two carrier frequencies, the given one of the two carrier frequencies being capable of transmitting control information.

22. The method as defined in claim 17, wherein at least one of the first synchronization preamble and the second synchronization preamble are transmitted over a smaller one of two carrier frequencies.

23. A method for generating a signal frame, comprising:

a) determining a first location within the signal frame for inserting a first synchronization preamble and a second location within the signal frame for inserting a second synchronization preamble;

b) generating the first synchronization preamble at least in part on a basis of the determined second location of the second synchronization preamble;

c) inserting the first synchronization preamble at the determined first location within the signal frame;

d) inserting the second synchronization preamble at the determined second location within the signal frame;

e) causing the signal frame to be issued towards a receiving device in a wireless communication environment.

24. The method as defined in claim 23, wherein determining the first location within the signal frame and the second location within the signal frame is done at least in part on a basis of frame length and channel conditions.

25. The method as defined in claim 23, wherein the signal frame is a frame of an Orthogonal Frequency Division Multiplexing (OFDM) signal.

26. The method as defined in claim 23, wherein generating the first synchronization sequence comprises generating a first synchronization sequence that conveys information indicative of the second location of the second synchronization preamble.

27. The method as defined in claim 23, wherein the method further comprises generating the second synchronization preamble, wherein generating the first synchronization preamble and the second synchronization preamble comprises causing at least one of the first synchronization preamble and second synchronization preamble to convey control information.

28. A method of receiving a signal frame in a wireless communication environment, the method comprising:

a) receiving a wireless signal comprising a plurality of signal frames, each signal frame comprising a first synchronization preamble and a second synchronization preamble;

b) identifying a first synchronization preamble within a given signal frame;

c) determining at least in part on a basis of information conveyed by the first synchronization preamble, a location within the given signal frame of the second synchronization preamble;

d) obtaining from a combination of the first synchronization preamble and the second synchronization preamble transmission signalling information.

29. The method as defined in claim 28, wherein the signal frame is a frame of an Orthogonal Frequency Division Multiplexing (OFDM) signal.

30. The method as defined in claim 28, wherein the information conveyed by the first synchronization preamble is carried via a first synchronization sequence.

31. A receiving device for receiving a signal frame in a wireless communication environment, the receiving device comprising:

a) receiving circuitry for receiving a wireless signal comprising a plurality of signal frames, each signal frame comprising a first synchronization preamble and a second synchronization preamble;

b) a control entity for;

i) identifying the first synchronization preamble within a given signal frame of the wireless signal;

ii) identifying, at least in part on a basis of information conveyed by the first synchronization preamble, the second synchronization preamble within the given signal frame;

iii) obtaining from at least one of the first synchronization preamble and the second synchronization preamble control information.