METHOD AND APPARATUS FOR POWER CONTROL OF FIRST DATA TRANSMISSION IN RANDOM ACCESS PROCEDURE OF FDMA COMMUNICATION SYSTEM

• US 20100041428A1
• Filed: 06/22/2009
• Published: 02/18/2010
• Est. Priority Date: 06/24/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Montojo, Juan, Chen, Wanshi, Meylan, Arnaud
• Granted Patent: US 8,494,572 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment

Abstract

Transmit power is controlled for a first uplink data transmission on Physical Uplink Shared Channel (PUSCH) during random access channel (RACH) procedure. Power control adjustment for the first PUSCH transmission is performed relative to the power spectral density used for successful PRACH transmission as adjusted for bandwidth difference, etc. The uplink Physical random access channel carries the RACH information that is transmitted by the user equipment (UE) during registrations or base station originated calls. A PRACH is composed of a number of preambles and a message portion. The preambles are a series of radio frequency power “steps” that increase in power according to the power step setting until the maximum number of preambles is reached or the base station acknowledges. Once the UE receives a positive indication, it transmits the message portion of the PRACH which consists of message data and control data with independent power gain control.

Claims

1. A method for transmit power control of a first message on physical uplink shared channel during a random access channel procedure on physical random access channel, comprising:

employing a processor executing computer executable instructions stored on a computer readable storage medium to implement following acts;

performing transmit power control for transmitting a random access channel preamble sufficient for successful receipt; and

setting transmit power control for a first message transmitted on physical uplink shared channel based at least in part upon the random access channel preamble that was successfully received.

2. The method of claim 1, further comprising performing transmit power control by determining a sufficient power spectral density for transmitting on physical uplink shared channel.

3. The method of claim 2, further comprising compensating for a bandwidth difference between the random access channel preamble and physical uplink shared channel.

4. The method of claim 2, further comprising accounting for offsets of the random access channel preamble not applicable to transmission of physical uplink shared channel in performing transmit power control.

5. The method of claim 1, further comprising:

transmitting on physical random access channel an indication of transmit power control used for the random access channel preamble that was successfully received; and

receiving a transmit power control command based in part upon the indication of transmit power control used for the random access channel preamble for physical uplink shared channel with a random access response.

6. The method of claim 5, further comprising receiving the transmit power control command for the physical uplink shared channel comprising a relative change in power spectral density for physical uplink shared channel from a power spectral density used for transmission of the random access channel preamble that was successfully received.

7. The method of claim 5, further comprising transmitting on physical random access channel the indication of transmit power control by conveying a number of retransmissions, wherein the transmit power control can be determined based upon a predefined power increase as a function of the number of retransmissions.

8. The method of claim 1, further comprising:

receiving a positive indication of reception of the random access channel preamble; and

transmitting a message portion containing message data or control data including an independent power gain control.

9. The method of claim 8, further comprising receiving the positive indication of reception of the random access channel preamble by receiving a random access response.

10. The method of claim 1, further comprising:

managing transmission of the random access channel preamble by a medium access control layer; and

managing transmission of physical uplink shared channel by a physical layer.

11. The method of claim 1, further comprising:

transmitting a random access channel preamble at a nominal transmit power value; and

retransmitting a random access channel preamble at a stepped up transmit power value in response to not receiving a random access response.

12. The method of claim 1, further comprising:

performing transmit power control for transmitting on random access channel preamble on physical random access channel by increasing in equal power steps; and

determining a relative transmit power control by tracking a number of equal power steps used until the random access channel preamble is successfully received.

13. The method of claim 12, further comprising determining the relative transmit power control by determining a maximum transmit power that limits the number of equal power steps.

14. The method of claim 1, further comprising:

transmitting a random access channel preamble at a nominal transmit power value managed by a medium access control layer;

performing transmit power control for transmitting on physical random access channel by increasing in equal power steps in response to failing to receive a positive indication of reception of the random access channel preamble;

retransmitting a random access channel preamble at a stepped up transmit power value;

determining a relative transmit power control by tracking a number of equal power steps;

receiving a positive indication of reception of the random access channel preamble;

transmitting on physical random access channel an indication of transmit power;

receiving a transmit power control command indicating an offset to a physical uplink shared channel power spectral density determined in part based on the transmit power of the random access channel preamble that was successfully received; and

setting transmit power control for the first message transmitted on physical uplink shared channel and managed transmission of physical uplink shared channel by a physical layer in accordance with the transmit power control command that was based in part upon the random access channel preamble that was successfully received.

15. The method of claim 14, further comprising setting transmit power control for the first message transmitted on physical uplink shared channel by adjusting for noise/interference variations.

16. The method of claim 14, further comprising setting transmit power control for the first message transmitted on physical uplink shared channel by adjusting for a power offset representing a different message receive sensitivity/quality requirement.

17. The method of claim 1, further comprising:

accessing a locally retained value for transmit power spectral density used for the random access channel preamble that was successfully received; and

setting transmit power control based at least in part upon the locally retained value.

18. The method of claim 1, further comprising adjusting for a partial path loss on physical uplink shared channel whereas total power control for physical random access channel is for full path loss.

19. The method of claim 1, further comprising adjusting for relative receive sensitivity of physical random access channel and physical uplink shared channel.

20. The method of claim 19, wherein the relative receive sensitivity is a function of at least one of a coverage requirement, target quality, physical layer coding, modulation, transmission bandwidth, and payload size.

21. The method of claim 1, further comprising adjusting for different noise/interference levels seen for the physical random access channel and the physical uplink shared channel.

22. A computer program product for transmit power control of a first message on physical uplink shared channel during a random access channel procedure on physical random access channel, comprising:

at least one computer readable storage medium storing computer executable instructions that, when executed by at least one processor, implement components comprising;

a first set of instructions for causing a computer to perform transmit power control on transmitting a random access channel preamble sufficient for successful receipt; and

a second set of instructions for causing the computer to set transmit power control for a first message transmitted on physical uplink shared channel based at least in part upon the random access channel preamble that was successfully received.

23. An apparatus for transmit power control of a first message on physical uplink shared channel during a random access channel procedure on physical random access channel, comprising:

at least one processor;

at least one computer readable storage medium storing computer executable instructions that, when executed by the at least one processor, implement components comprising;

means for performing transmit power control on transmitting a random access channel preamble sufficient for successful receipt; and

means for setting transmit power control for a first message transmitted on physical uplink shared channel based at least in part upon the random access channel preamble that was successfully received.

24. An apparatus for transmit power control of a first message on physical uplink shared channel during a random access channel procedure on physical random access channel, comprising:

a transmitter for transmitting a physical random access channel and physical uplink shared channel;

a receiver;

a medium access control layer for performing transmit power control on transmitting a random access channel preamble; and

a physical layer for setting transmit power control for a first message transmitted on physical uplink shared channel based upon the random access channel preamble that was successfully received.

25. The apparatus of claim 24, wherein the medium access control layer is further for performing transmit power control by determining a sufficient power spectral density for transmitting on physical uplink shared channel.

26. The apparatus of claim 25, wherein the physical layer is further for compensating for a bandwidth difference between the random access channel preamble and physical uplink shared channel.

27. The apparatus of claim 25, wherein the physical layer is further for accounting for offsets of the random access channel preamble not applicable to transmission of physical uplink shared channel in performing transmit power control.

28. The apparatus of claim 24, wherein the medium access control layer is further for transmitting on physical random access channel an indication of transmit power used for the random access channel preamble that was successfully received;

and

the receiver is further for receiving a transmit power control command for physical uplink shared channel with a random access response based at least in part upon the indication.

29. The apparatus of claim 28, wherein the receiver is further for receiving a transmit power control command for the physical uplink shared channel comprising a relative change from a transmit power level used for the random access channel preamble that was successfully received.

30. The apparatus of claim 29, further comprising transmitting on physical random access channel the indication of transmit power control by conveying a number of retransmissions, wherein the transmit power can be determined based upon a predefined power increase as a function of the number of retransmissions.

31. The apparatus of claim 28, wherein the receiver is further for receiving a positive indication of random access channel preamble reception;

and

the transmitter is further for transmitting a message portion containing message data or control data including an independent power gain control.

32. The apparatus of claim 31, wherein the receiver is further for receiving the positive indication of reception of the random access channel preamble by receiving a random access response.

33. The apparatus of claim 24, wherein the medium access control layer is further for transmitting a random access channel preamble at a nominal transmit power value, and for retransmitting a random access channel preamble at a stepped up transmit power value in response to not receiving a random access response.

34. The apparatus of claim 24, wherein the medium access control layer is further for performing transmit power control for physical random access channel transmission by increasing in equal power steps, and for determining a relative transmit power control by tracking a number of equal power steps used until a physical random access channel preamble is successfully received.

35. The apparatus of claim 24, wherein the medium access control layer is further for transmitting a random access channel preamble at a nominal transmit power value managed by a medium access control layer, for performing transmit power control for transmitting random access channel preamble by increasing in equal power steps in response to failing to receive a positive indication of reception, for retransmitting a random access channel preamble at a stepped up transmit power value, and for determining a relative transmit power control by tracking a number of equal power steps;

the receiver is further for receiving the positive indication of reception of the random access channel preamble;

the medium access control layer is further for transmitting an indication of transmit power on physical random access channel;

the receiver is further for receiving a transmit power control command indicating an offset to physical uplink shared channel power spectral density determined in part based on the transmit power of the random access channel preamble that was successfully received; and

the physical layer is further for setting transmit power control for the first message transmitted on physical uplink shared channel and managed transmission of physical uplink shared channel by a physical layer in accordance with the transmit power control command that was based at least in part upon random access channel preamble that was successfully received.

36. The apparatus of claim 35, wherein the physical layer is further for determining the relative transmit power control by determining a maximum transmit power that limits the number of equal power steps.

37. The apparatus of claim 35, wherein the physical layer is further for setting transmit power control for the first message transmitted on physical uplink shared channel by adjusting for noise/interference variations.

38. The apparatus of claim 35, wherein the physical layer is further for setting transmit power control for the first message transmitted on physical uplink shared channel by adjusting for a power offset representing a different message receive sensitivity/quality requirement.

39. The apparatus of claim 24, wherein the physical layer is further for accessing a locally retained value for transmit power spectral density used for the random access channel preamble that was successfully received, and for setting transmit power control based at least in part upon the locally retained value.

40. The apparatus of claim 24, wherein the physical layer is further for adjusting for a partial path loss on physical uplink shared channel whereas total power control for physical random access channel is for full path loss.

41. The apparatus of claim 24, wherein the physical layer is further for adjusting for relative receive sensitivity of physical random access channel and physical uplink shared channel.

42. The apparatus of claim 41, wherein the relative receive sensitivity is a function of at least one of a coverage requirement, target quality, physical layer coding, modulation, transmission bandwidth, and payload size.

43. A method for transmit power control of a first message on physical uplink shared channel during a random access channel procedure on physical random access channel, comprising:

employing a processor executing computer executable instructions stored on a computer readable storage medium to implement following acts;

receiving a random access channel preamble;

acknowledging successful receipt of the random access channel preamble;

receiving a random access channel message containing an indication of transmit power control used for the random access channel preamble that was successfully received; and

transmitting a random access response including a transmit power control command for a first message transmitted on physical uplink shared channel based at least in part upon a transmit power control for the random access channel preamble that was successfully received.

44. The method of claim 43, further comprising transmitting a transmit power control command for the physical uplink shared channel comprising a relative power change from transmit power used for the random access channel preamble that was successfully received.

45. The method of claim 44, further comprising:

transmitting a positive indication of reception of the random access channel preamble; and

receiving a message portion containing message data or control data including an independent power gain control.

46. The method of claim 43, further comprising determining transmit power control command for the first message transmitted on physical uplink shared channel by determining a sufficient power spectral density for transmitting on physical uplink shared channel of the first message.

47. The method of claim 43, further comprising determining transmit power control command for the first message transmitted on physical uplink shared channel by compensating for a bandwidth difference between the random access channel preamble and physical uplink shared channel.

48. The method of claim 43, further comprising determining transmit power control command for the first message transmitted on physical uplink shared channel by accounting for offsets of the random access channel preamble not applicable to transmission of physical uplink shared channel.

49. The method of claim 43, further comprising determining transmit power control command for the first message transmitted on physical uplink shared channel by adjusting for noise/interference variations.

50. The method of claim 43, further comprising determining transmit power control command for the first message transmitted on physical uplink shared channel by setting transmit power control for the first message transmitted on physical uplink shared channel by adjusting for a power offset representing a different message receive sensitivity/quality requirement.

51. A computer program product for transmit power control of a first message on physical uplink shared channel during a random access channel procedure on physical random access channel, comprising:

at least one computer readable storage medium storing computer executable instructions that, when executed by at least one processor, implement components comprising;

a first set of instructions for receiving a random access channel preamble;

a second set of instructions for acknowledging successful receipt of the random access channel preamble;

a third set of instructions for receiving a random access channel message containing an indication of transmit power control used for the random access channel preamble that was successfully received; and

a fourth set of instructions for transmitting a random access response including a transmit power control command for a first message transmitted on physical uplink shared channel based at least in part upon a transmit power control for the random access channel preamble that was successfully received.

52. An apparatus for transmit power control of a first message on physical uplink shared channel during a random access channel procedure on physical random access channel, comprising:

at least one processor;

at least one computer readable storage medium storing computer executable instructions that, when executed by the at least one processor, implement components comprising;

means for receiving a random access channel preamble;

means for acknowledging successful receipt of the random access channel preamble;

means for receiving a random access channel message containing an indication of transmit power control used for the random access channel preamble that was successfully received; and

means for transmitting a random access response including a transmit power control command for a first message transmitted on physical uplink shared channel based at least in part upon a transmit power control for the random access channel preamble that was successfully received.

53. An apparatus for transmit power control of a first message on physical uplink shared channel during a random access channel procedure on physical random access channel, comprising:

a receiver for receiving a random access channel preamble on a physical random access channel;

a transmitter for acknowledging successfully receipt of the random access channel preamble;

the receiver further for receiving a random access channel message containing an indication of transmit power control for the random access channel preamble that was successfully received; and

a computing platform for transmitting via the transmitter a random access response including a transmit power control command for a first message transmitted on physical uplink shared channel based at least in part upon a transmit power control for the random access channel preamble that was successfully received.

54. The apparatus of claim 53, wherein the computing platform is further for transmitting via the transmitter a transmit power control command for the physical uplink shared channel comprising a relative power change from transmit power used for the random access channel preamble that was successfully received.

55. The apparatus of claim 54, wherein the computing platform is further for transmitting via the transmitter a positive indication of random access channel preamble reception;

and

the receiver is further for receiving a message portion containing message data or control data including an independent power gain control.

56. The apparatus of claim 53, wherein the computing platform is further for determining transmit power control command for the first message transmitted on physical uplink shared channel by determining a sufficient power spectral density for transmitting on physical uplink shared channel of the first message.

57. The apparatus of claim 54, wherein the computing platform is further for determining transmit power control command for the first message transmitted on physical uplink shared channel by compensating for a bandwidth difference between the random access channel preamble and physical uplink shared channel.

58. The apparatus of claim 53, wherein the computing platform is further for determining transmit power control command for the first message transmitted on physical uplink shared channel by accounting for offsets of the random access channel preamble not applicable to transmission of physical uplink shared channel.

59. The apparatus of claim 53, wherein the computing platform is further for determining transmit power control command for the first message transmitted on physical uplink shared channel by adjusting for noise/interference variations.

60. The apparatus of claim 53, wherein the computing platform is further for determining transmit power control command for the first message transmitted on physical uplink shared channel by setting transmit power control for the first message transmitted on physical uplink shared channel by adjusting for a power offset representing a different message receive sensitivity/quality requirement.