Pilot transmission in a wireless communication system

• US 8,929,551 B2
• Filed: 05/03/2013
• Issued: 01/06/2015
• Est. Priority Date: 01/05/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Khandekar, Aamod, Gorokhov, Alexei, Borran, Mohammad J., Prakash, Rajat
• Primary Examiner(s): Chai, Longbit
• Application Number:
  US13/886,912
• Publication Number:
  US 20130243039A1
• Time in Patent Office: 613 Days
• Field of Search: 380/270
• US Class Current: 380/270
• CPC Class Codes: H04B 1/7156 Arrangements for sequence synchronisation
• CPC Class Codes: H04J 13/10 Code generation
• CPC Class Codes: H04L 27/261 Details of reference signals
• CPC Class Codes: H04L 27/2613 Structure of the reference signals

Abstract

Techniques for transmitting pilot and traffic data are described. In one aspect, a terminal may scramble its pilot with a scrambling sequence generated based on a set of static and dynamic parameters. The static parameter(s) have fixed value for an entire communication session for the terminal. The dynamic parameter(s) have variable value during the communication session. The terminal may generate a scrambling sequence by hashing the set of parameters to obtain a seed and initializing a pseudo-random number (PN) generator with the seed. The terminal may then generate the pilot based on the scrambling sequence. In another aspect, the terminal may use different scrambling sequences for pilot and traffic data. A first scrambling sequence may be generated based on a first set of parameters and used to generate the pilot. A second scrambling sequence may be generated based on a second set of parameters and used to scramble traffic data.

Claims

1. A method implemented in an apparatus for wireless communication, comprising:

generating, via the apparatus, a scrambling sequence for a reverse link transmission based on a set of parameters comprising at least one static parameter and at least one dynamic parameter, each of the at least one dynamic parameter having a variable value during a communication session for a terminal, the at least one dynamic parameter comprising a parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission;

generating, via the apparatus, a pilot based on the scrambling sequence; and

sending, via the apparatus at a system time, the pilot from the terminal to at least one sector in the reverse link transmission.

2. The method of claim 1, wherein the generating the scrambling sequence comprises

generating a seed based on the set of parameters, and

generating the scrambling sequence based on the seed.

3. The method of claim 1, wherein the at least one static parameter comprises a parameter that is independent of a serving sector for the terminal.

4. The method of claim 1, wherein the time frequency block associated with the reverse link transmission covers a plurality of contiguous subcarriers in a plurality of symbol periods.

5. The method of claim 1, wherein the time frequency block associated with the reverse link transmission comprises a Code Division Multiple Access (CDMA) subsegment.

6. The method of claim 1, wherein the generating the pilot comprises generating at least one Single-Carrier Frequency Division Multiple Access (SC-FDMA) symbol for the pilot.

7. The method of claim 1, wherein the reverse link transmission comprises a reverse link control channel.

8. The method of claim 1, wherein the reverse link transmission comprises a reverse link data channel.

9. The method of claim 1, wherein each of the at least one static parameter has a fixed value for an entire communication session for the terminal.

10. The method of claim 1, further comprising obtaining the at least one static parameter after completing initial system access by the terminal.

11. The method of claim 1, wherein the generating the pilot based on the scrambling sequence comprises generating the pilot based further on pilot data comprising an orthogonal sequence, a sequence of all ones, a known pseudo-random number sequence, or a combination thereof.

12. The method of claim 1, wherein the at least one static parameter comprises an identifier (ID) of a sector initially accessed by the terminal, or an ID assigned to the terminal by the initial accessed sector, or an access sequence index used by the terminal for initial system access, or time of the initial system access by the terminal, or a combination thereof.

13. The method of claim 1, further comprising receiving a power control (PC) command from a serving sector for the terminal, the PC command being determined based on the pilot, and adjusting transmit power based on the PC command.

14. The method of claim 1, further comprising receiving a pilot quality indicator (PQI) from each of the at least one sector, the PQI from each sector being determined based on the pilot, and selecting one of the at least one sector as a serving sector for the terminal based on the PQI received from each of the at least one sector.

15. The method of claim 1, further comprising performing handoff from a current serving sector to a new serving sector, and using the set of parameters to generate the scrambling sequence for pilot sent to the new serving sector.

16. An apparatus for wireless communication, comprising:

at least one processor configured to

generate a scrambling sequence for a reverse link transmission based on a set of parameters comprising at least one static parameter and at least one dynamic parameter, each of the at least one dynamic parameter having a variable value during a communication session for a terminal, the at least one dynamic parameter comprising a parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission,

generate a pilot based on the scrambling sequence, and

send, at a system time, the pilot from the terminal to at least one sector in the reverse link transmission; and

a memory coupled to the at least one processor.

17. The apparatus of claim 16, wherein the at least one processor is further configured to generate a seed based on the set of parameters and to generate the scrambling sequence based on the seed.

18. The apparatus of claim 16, wherein the at least one static parameter comprises a parameter that is independent of a serving sector for the terminal.

19. The apparatus of claim 16, wherein the time frequency block associated with the reverse link transmission covers a plurality of contiguous subcarriers in a plurality of symbol periods.

20. The apparatus of claim 16, wherein the at least one processor is further configured to generate at least one Single-Carrier Frequency Division Multiple Access (SC-FDMA) symbol for the pilot.

21. The apparatus of claim 16, wherein the reverse link transmission comprises a reverse link control channel.

22. The apparatus of claim 16, wherein the reverse link transmission comprises a reverse link data channel.

23. The apparatus of claim 16, wherein each of the at least one static parameter has a fixed value for an entire communication session for the terminal.

24. The apparatus of claim 16, wherein the at least one processor is further configured to generate the pilot based further on pilot data comprising an orthogonal sequence, a sequence of all ones, a known pseudo-random number sequence, or a combination thereof.

25. The apparatus of claim 16, wherein the at least one static parameter comprises an identifier (ID) of a sector initially accessed by the terminal, or an ID assigned to the terminal by the initial accessed sector, or an access sequence index used by the terminal for initial system access, or time of the initial system access by the terminal, or a combination thereof.

26. An apparatus for wireless communication, comprising:

means for generating a scrambling sequence for a reverse link transmission based on a set of parameters comprising at least one static parameter and at least one dynamic parameter, each of the at least one dynamic parameter having a variable value during a communication session for a terminal, the at least one dynamic parameter comprising a parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission;

means for generating a pilot based on the scrambling sequence; and

means for sending, at a system time, the pilot from the terminal to at least one sector in the reverse link transmission.

27. The apparatus of claim 26, wherein the means for generating the scrambling sequence generates a seed based on the set of parameters and generates the scrambling sequence based on the seed.

28. A non-transitory processor-readable storage medium having program code, which when executed by at least one processor, results in the at least one processor performing functions of:

generating a scrambling sequence for a reverse link transmission based on a set of parameters comprising at least one static parameter and at least one dynamic parameter, each of the at least one dynamic parameter having a variable value during a communication session for a terminal, the at least one dynamic parameter comprising a parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission;

generating a pilot based on the scrambling sequence; and

sending, at a system time, the pilot to at least one sector in the reverse link transmission.

29. A method implemented in an apparatus for wireless communication, comprising:

receiving, via the apparatus, a pilot in a reverse link transmission from a terminal after the pilot being transmitted, at a system time, on the reverse link;

generating, via the apparatus, a scrambling sequence for the reverse link transmission based on a set of parameters comprising at least one static parameter and at least one dynamic parameter, each of the at least one dynamic parameter having a variable value during a communication session for the terminal, the at least one dynamic parameter comprising a parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission; and

descrambling, via the apparatus, the received pilot with the scrambling sequence to obtain descrambled pilot for the terminal.

30. The method of claim 29, wherein the generating the scrambling sequence comprises

generating a seed based on the set of parameters, and

generating the scrambling sequence based on the seed.

31. The method of claim 29, wherein the at least one static parameter comprises an identifier (ID) of a sector initially accessed by the terminal, or an ID assigned to the terminal by the initial accessed sector, or an access sequence index used by the terminal for initial system access, or time of the initial system access by the terminal, or a combination thereof.

32. The method of claim 29, further comprising determining received pilot strength for the terminal based on the descrambled pilot, generating a pilot quality indicator (PQI) based on the received pilot strength, and sending the PQI to the terminal.

33. The method of claim 29, further comprising determining received signal quality for the terminal based on the descrambled pilot, generating a power control (PC) command based on the received signal quality, and sending the PC command to the terminal.

34. An apparatus for wireless communication, comprising:

at least one processor configured to

receive a pilot in a reverse link transmission from a terminal after the pilot being transmitted, at a system time, on the reverse link,

generate a scrambling sequence for the reverse link transmission based on a set of parameters comprising at least one static parameter and at least one dynamic parameter, each of the at least one dynamic parameter having a variable value during a communication session for the terminal, the at least one dynamic parameter comprising a parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission, and

descramble the received pilot with the scrambling sequence to obtain descrambled pilot for the terminal; and

a memory coupled to the at least one processor.

35. The apparatus of claim 34, wherein the at least one processor is configured to generate a seed based on the set of parameters and to generate the scrambling sequence based on the seed.

36. An apparatus for wireless communication, comprising:

means for receiving a pilot in a reverse link transmission from a terminal after the pilot being transmitted, at a system time, on the reverse link,

means for generating a scrambling sequence for the reverse link transmission based on a set of parameters comprising at least one static parameter and at least one dynamic parameter, each of the at least one dynamic parameter having a variable value during a communication session for the terminal, the at least one dynamic parameter comprising a parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission, and

means for descrambling the received pilot with the scrambling sequence to obtain descrambled pilot for the terminal; and

a memory coupled to the at least one processor.

37. The apparatus of claim 36, wherein the means for generating the scrambling sequence generates a seed based on the set of parameters and generates the scrambling sequence based on the seed.

38. A non-transitory processor-readable storage medium having program code, which when executed by at least one processor, results in the at least one processor performing functions of:

receiving, via an apparatus for wireless communication, a pilot in a reverse link transmission from a terminal after the pilot being transmitted, at a system time, on the reverse link;

generating, via the apparatus, a scrambling sequence for the reverse link transmission based on a set of parameters comprising at least one static parameter and at least one dynamic parameter, each of the at least one dynamic parameter having a variable value during a communication session for the terminal, the at least one dynamic parameter comprising a parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission; and

descrambling, via the apparatus, the received pilot with the scrambling sequence to obtain descrambled pilot for the terminal.

39. A method implemented in an apparatus for wireless communication, comprising:

generating, via the apparatus, a first scrambling sequence for a reverse link transmission based on a first set of parameters;

generating, via the apparatus, a pilot based on the first scrambling sequence;

sending, via the apparatus, the pilot at a system time to at least one sector including a serving sector for a terminal;

generating, via the apparatus, a second scrambling sequence for the reverse link transmission based on a second set of parameters different from the first set of parameters;

scrambling, via the apparatus, traffic data based on the second scrambling sequence to obtain scrambled traffic data; and

sending, via the apparatus, the scrambled traffic data to the serving sector, wherein at least one of said first and second sets of parameters comprise a dynamic parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission.

40. The method of claim 39, wherein the generating the first scrambling sequence comprises generating a first seed based on the first set of parameters, and generating the first scrambling sequence based on the first seed, and wherein the generating the second scrambling sequence comprises generating a second seed based on the second set of parameters, and generating the second scrambling sequence based on the second seed.

41. The method of claim 39, wherein the first set of parameters comprises at least one parameter independent of the serving sector, and wherein the second set of parameters comprises at least one parameter dependent on the serving sector.

42. The method of claim 39, wherein the first set of parameters comprises an identifier (ID) of a sector initially accessed by the terminal, or an ID assigned to the terminal by the initial accessed sector, or an access sequence index used by the terminal for initial system access, or time of the initial system access by the terminal, or a combination thereof.

43. The method of claim 39, wherein the second set of parameters comprises an identifier (ID) of the serving sector, or an ID assigned to the terminal by the serving sector, or a combination thereof.

44. An apparatus for wireless communication, comprising:

at least one processor configured to

generate a first scrambling sequence for a reverse link transmission based on a first set of parameters,

generate a pilot based on the first scrambling sequence,

send the pilot at a system time to at least one sector including a serving sector for a terminal,

generate a second scrambling sequence for the reverse link transmission based on a second set of parameters different from the first set of parameters,

scramble traffic data based on the second scrambling sequence to obtain scrambled traffic data, and

send the scrambled traffic data to the serving sector, wherein at least one of the first and second sets of parameters comprise a dynamic parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission; and

a memory coupled to the at least one processor.

45. The apparatus of claim 44, wherein the at least one processor is configured to generate a first seed based on the first set of parameters, to generate the first scrambling sequence based on the first seed, to generate a second seed based on the second set of parameters, and to generate the second scrambling sequence based on the second seed.

46. An apparatus for wireless communication, comprising:

means for generating a first scrambling sequence for a reverse link transmission based on a first set of parameters,

means for generating a pilot based on the first scrambling sequence,

means for sending the pilot at a system time to at least one sector including a serving sector for a terminal,

means for generating a second scrambling sequence for the reverse link transmission based on a second set of parameters different from the first set of parameters,

means for scrambling traffic data based on the second scrambling sequence to obtain scrambled traffic data, and

means for sending the scrambled traffic data to the serving sector, wherein at least one of the first and second sets of parameters comprise a dynamic parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission; and

a memory coupled to the at least one processor.

47. The apparatus of claim 46, wherein the means for generating the first scrambling sequence generates a first seed based on the first set of parameters and generates the first scrambling sequence based on the first seed, and wherein the means for generating the second scrambling sequence generates a second seed based on the second set of parameters and generates the second scrambling sequence based on the second seed.

48. A non-transitory processor-readable storage medium having program code, which when executed by at least one processor, results in the at least one processor performing functions of:

generating, via an apparatus for wireless communication, a first scrambling sequence for a reverse link transmission based on a first set of parameters;

generating, via the apparatus, a pilot based on the first scrambling sequence;

sending, via the apparatus, the pilot at a system time to at least one sector including a serving sector for a terminal;

generating, via the apparatus, a second scrambling sequence for the reverse link transmission based on a second set of parameters different from the first set of parameters;

scrambling, via the apparatus, traffic data based on the second scrambling sequence to obtain scrambled traffic data; and

sending, via the apparatus, the scrambled traffic data to the serving sector, wherein at least one of said first and second sets of parameters comprise a dynamic parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission.

49. A method for wireless communication, comprising:

receiving a pilot associated with a reverse link transmission from a terminal after the pilot being transmitted, at a system time, on the reverse link;

generating a first scrambling sequence based on a first set of parameters;

descrambling the received pilot with the first scrambling sequence to obtain descrambled pilot;

receiving traffic data associated with the reverse link transmission from the terminal;

generating a second scrambling sequence based on a second set of parameters different from the first set of parameters; and

descrambling the received traffic data with the second scrambling sequence to obtain descrambled traffic data, wherein at least one of said first and second sets of parameters comprise a dynamic parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission.

50. The method of claim 49, wherein the generating the first scrambling sequence comprises generating a first seed based on the first set of parameters, and generating the first scrambling sequence based on the first seed, and wherein the generating the second scrambling sequence comprises generating a second seed based on the second set of parameters, and generating the second scrambling sequence based on the second seed.

51. An apparatus for wireless communication, comprising:

at least one processor configured to

receive a pilot in a reverse link transmission from a terminal after the pilot being transmitted, at a system time, on the reverse link,

generate a first scrambling sequence for the reverse link transmission based on a first set of parameters,

descramble the received pilot with the first scrambling sequence to obtain descrambled pilot,

receive traffic data in the reverse link transmission from the terminal,

generate a second scrambling sequence for the reverse link transmission based on a second set of parameters different from the first set of parameters, and

descramble the received traffic data with the second scrambling sequence to obtain descrambled traffic data, wherein at least one of said first and second sets of parameters comprise a dynamic parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission; and

a memory coupled to the at least one processor.

52. The apparatus of claim 51, wherein the at least one processor is configured to generate a first seed based on the first set of parameters, to generate the first scrambling sequence based on the first seed, to generate a second seed based on the second set of parameters, and to generate the second scrambling sequence based on the second seed.

53. An apparatus for wireless communication, comprising:

means for receiving a pilot associated with a reverse link transmission from a terminal after the pilot being transmitted, at a system time, on the reverse link;

means for generating a first scrambling sequence based on a first set of parameters;

means for descrambling the received pilot with the first scrambling sequence to obtain descrambled pilot;

means for receiving traffic data associated with the reverse link transmission from the terminal;

means for generating a second scrambling sequence based on a second set of parameters different from the first set of parameters; and

means for descrambling the received traffic data with the second scrambling sequence to obtain descrambled traffic data, wherein at least one of said first and second sets of parameters comprise a dynamic parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission.

54. The apparatus of claim 53, wherein the means for generating the first scrambling sequence generates a first seed based on the first set of parameters and generates the first scrambling sequence based on the first seed, and wherein the means for generating the second scrambling sequence generates a second seed based on the second set of parameters and generates the second scrambling sequence based on the second seed.

55. A non-transitory processor-readable storage medium having program code, which when executed by at least one processor, results in the at least one processor performing functions of:

receiving a pilot associated with a reverse link transmission from a terminal after the pilot being transmitted, at a system time, on the reverse link;

generating a first scrambling sequence based on a first set of parameters;

descrambling the received pilot with the first scrambling sequence to obtain descrambled pilot;

receiving traffic data associated with the reverse link transmission from the terminal;

generating a second scrambling sequence based on a second set of parameters different from the first set of parameters; and

descrambling the received traffic data with the second scrambling sequence to obtain descrambled traffic data, wherein at least one of said first and second sets of parameters comprise a dynamic parameter associated with frequency resources of a hopping pattern utilized for frequency hopping of a time frequency block associated with the reverse link transmission.