Method and apparatus for testing wireless communication channels

• US 20020009134A1
• Filed: 01/09/2001
• Published: 01/24/2002
• Est. Priority Date: 01/10/2000
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Fischel, Scott Eduard, Mir, Idreas A.
• Granted Patent: US 6,542,538 B2
• Time in Patent Office: Days
• US Class Current: 375/224
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04L 1/244 test sequence generators

Abstract

Techniques to test a wireless communication link. A traffic channel is tested via a test data service option (TDSO) that may be negotiated and connected similar to other services. Test parameters values may be proposed, accepted or rejected, and negotiated. Test data for a channel is generated based on a defined data pattern or a pseudo-random number generator. Sufficient test data may be generated based on the generator for a test interval, stored to a buffer, and thereafter retrieved from a particular section of the buffer to form data block(s) for each “active” frame. The traffic channel may be tested using discontinuous transmission. A two-state Markov chain determines whether or not to transmit test data for each frame. The average frame activity and average burst length are defined by selecting the probabilities for transitioning between the ON/OFF states of the Markov chain, which may be driven by a second generator.

Claims

1. A method for generating test data for testing a particular channel in a wireless communication system, comprising:

generating a sequence of data bits based on a pseudo-random number generator; and

forming a plurality of data blocks for transmission over a plurality of time intervals on the particular channel, wherein each data block includes at least a portion of the generated sequence of data bits.

2. The method of claim 1, wherein each time interval corresponds to a frame on the particular traffic channel, and wherein the sequence of data bits includes at least N times a maximum number of bits expected to be transmitted for one fame on the particular channel, where N is two or greater.

3. The method of claim 1, further comprising:

storing the generated sequence of data bits to a buffer.

4. The method of claim 3, wherein the buffer is operated as a circular buffer, the method further comprising:

retrieving data bits for each data block from a particular section of the circular buffer.

5. The method of claim 4, wherein a starting location in the circular buffer from which to retrieve data bits for a particular data block is determined based in part on a value obtained from the pseudo-random number generator.

6. The method of claim 5, further comprising:

formatting the value obtained from the pseudo-random number generator; and

advancing a pointer for the circular buffer by a number of positions determined based on the formatted number.

7. The method of claim 6, wherein a 31-bit value is obtained from the pseudo-random number generator, and wherein the formatting includes

generating a 24-bit number with 24 most significant bits of the 31-bit value, and

generating the formatted number with six least significant bits of the 24-bit number.

8. The method of claim 1, wherein the generating the sequence of data bits includes

obtaining a value corresponding to a current state of the pseudo-random number generator,

forming a set of data bits based on the obtained value, and

updating the pseudo-random number generator.

9. The method of claim 8, wherein the generating the sequence of data bits further includes

repeating the obtaining, forming, and updating a plurality of times, and

concatenating a plurality of sets of data bits formed based on a plurality of values obtained from the pseudo-random number generator to generate the sequence of data bits.

10. The method of claim 8, wherein the forming includes

extracting a most significant portion of the obtained value, and

rearranging bytes in the extracted most significant portion to form the set of data bits.

11. The method of claim 10, wherein a 31-bit value is obtained from the pseudo-random number generator, a 24-bit value is extracted from the most significant portion of the obtained value, and the bytes of the 24-bit value are rearranged in little-endian order.

12. The method of claim 1, further comprising:

reinitializing the pseudo-random number generator at each synchronization time corresponding to a start of a new test interval.

13. The method of claim 12, wherein each test interval has a duration of 10.24 seconds.

14. The method of claim 12, wherein the synchronization time is determined based in part on a system frame number for a frame on the particular traffic channel.

15. The method of claim 14, wherein the synchronization time is further determined based on a public long code mask (PLCM) assigned to a remote terminal designated to receive the data blocks.

16. The method of claim 1, wherein a plurality of channels are concurrently tested, and wherein a plurality of pseudo-random number generators are used to generate test data for testing the plurality of channels.

17. The method of claim 16, wherein one pseudo-random number generator is used to generate test data for each channel.

18. The method of claim 17, wherein the test data generated for each channel is stored to a respective buffer.

19. A method for generating test data for testing a particular channel in a wireless communication system, comprising:

selecting a particular one of a plurality of available test data types;

generating a sequence of data bits of the selected test data type; and

forming a plurality of data blocks for transmission over a plurality of time intervals on the particular channel, wherein each data block includes at least a portion of the generated sequence of data bits.

20. The method of claim 19, wherein the available test data types include test data generated based on a defined data pattern and test data pseudo-randomly generated.

21. The method of claim 20, wherein the sequence of data bits generated based on the defined data pattern includes a plurality of bytes of a particular value.

22. The method of claim 21, wherein the defined data pattern is a sequence of a particular number of ones.

23. A method for testing a particular channel in a wireless communication system, comprising:

determining a transmission state of a current frame for the particular channel, wherein transmission on the particular channel occurs over frames, and wherein each frame corresponds to a particular time interval;

generating one or more blocks of test data for the current frame if the determined transmission state indicates that test data is to be transmitted; and

transmitting the one or more generated blocks of test data on the particular channel.

24. The method of claim 23, further comprising:

maintaining a two-state Markov chain to represent the transmission state for the particular channel.

25. The method of claim 24, wherein the two-state Markov chain includes an ON state signifying transmission of test data on the particular channel and an OFF state signifying no transmission of test data on the particular channel.

26. The method of claim 25, further comprising:

maintaining a pseudo-random number generator to determine transitions between the ON and OFF states of the Markov chain.

27. The method of claim 26, further comprising:

initializing the pseudo-random number generator prior to start of testing the particular channel.

28. The method of claim 26, further comprising:

obtaining a value based on a current state of the pseudo-random number generator; and

transitioning from the ON state to the OFF state if a current state of the Markov chain is the ON state and the obtained value is below a first threshold value.

29. The method of claim 28, further comprising:

transitioning from the OFF state to the ON state if the current state of the Markov chain is the OFF state and the obtained value is below a second threshold value.

30. The method of claim 29, wherein the first and second thresholds values are configurable test parameters.

31. The method of claim 25, wherein transition between the ON state and the OFF state is based on a first probability and transition between the OFF state and the ON state is based on a second probability.

32. The method of claim 31, wherein the first and second probabilities are selected to achieve a particular average frame activity on the particular channel indicative of an average duty cycle for transmissions on the channel.

33. The method of claim 32, wherein the average frame activity is a selectable test parameter.

34. The method of claim 31, wherein the first and second probabilities are selected to achieve a particular average burst length on the particular channel indicative of an average duration for transmissions on the channel.

35. The method of claim 23, wherein transmission of test data occurs on the particular channel for a particular ON duration followed by no transmission of test data for a particular OFF duration.

36. The method of claim 35, wherein the ON and OFF durations are configurable test parameters.

37. The method of claim 26, wherein a plurality of channels are concurrently tested, and wherein a two-state Markov chain is maintained for each channel being tested.

38. The method of claim 37, wherein one pseudo-random number generator is maintained to determine transitions between Markov states for each set of one or more channels having a frame interval that is different from frame intervals of other channels being tested.

39. The method of claim 37, wherein a first pseudo-random number generator is maintained to determine transitions between Markov states for a first set of one or more channels having a first frame interval, and wherein a second pseudo-random number generator is maintained to determine transitions between Markov states for a second set of one or more channels having a second frame interval.

40. The method of claim 39, wherein the first frame interval is 20 msec and the second frame interval is 40 msec or 80 msec.

41. A method for testing a plurality of channels in a wireless communication system, comprising:

defining values for a set of test parameters for each of the plurality of channels to be tested; and

testing each of the plurality of channels in accordance with respective values defined for the set of test parameters.

42. The method of claim 41, wherein the plurality of channels have two or more different frame lengths.

43. The method of claim 41, wherein the plurality of channels have frame lengths selected from the group consisting of 5 msec, 20 msec, 40 msec, and 80 msec.

44. The method of claim 41, wherein the plurality of channels include at least one forward traffic channel and at least one reverse traffic channel.

45. The method of claim 41, further comprising:

generating data blocks for transmission over a plurality of frames on the plurality of channels, wherein each data block includes a header that identifies the particular channel on which the data block is transmitted.

46. The method of claim 41, wherein each traffic channel to be tested is associate with a respective sequence of test data bits.

47. The method of claim 41, wherein each traffic channel to be tested is associate with a respective average frame activity.

48. The method of claim 41, wherein each traffic channel to be tested is associate with a respective average burst length.

49. The method of claim 41, further comprising:

maintaining a two-state Markov chain to represent a transmission state for each of the plurality of channels, wherein the two-state Markov chain for each channel includes an ON state signifying transmission of test data on the channel and an OFF state signifying no transmission of test data on the channel.

50. The method of claim 49, further comprising:

maintaining one or more pseudo-random number generators to determine transitions between the ON and OFF states of Markov chains for the plurality of channels.

51. The method of claim 50, wherein one pseudo-random number generator is maintained for each set of one or more channels having same frame length.

52. The method of claim 51, wherein a first pseudo-random number generator is maintained for one or more channels having frame length of 20 msec and a second pseudo-random number generator is maintained for one or more channels having frame length of 40 msec or 80 msec.

53. A method for testing a particular channel in a wireless communication system, comprising:

sending from a first entity to a second entity a first message having included therein one or more proposed values for one or more parameters for testing the particular channel; and

receiving from the second entity a response message rejecting or accepting the one or more proposed values sent in the first message.

54. The method of claim 53, wherein the response message includes one or more alternative values for one or more parameters rejected by the second entity.

55. The method of claim 53, further comprising:

sending to the second entity a second message having included therein one or more values for one or more parameters rejected by the second entity.

56. The method of claim 53, wherein the first entity is a remote terminal and the second entity is a base station in the communication system.

57. A transmitting entity in a wireless communication system, comprising:

at least one pseudo-random number generator, each generator configured to generate pseudo-random numbers used to generate a sequence of data bits; and

at least one buffer operatively coupled to the at least one generator, each buffer configured to store a respective generated sequence of data bits, and

wherein a plurality of data blocks are formed for transmission over a plurality of time intervals on a particular channel, and wherein each data block includes at least a portion of a particular sequence of data bits from a particular buffer.

58. The transmitting entity claim 57, further comprising:

a controller configured to select one of a plurality of available test data types, wherein the available test data types include test data generated based on a defined data pattern and test data pseudo-randomly generated.

59. The transmitting entity claim 58, wherein the controller is further configured to determine a transmission state of a current frame for the particular channel, and wherein the transmission state is either an ON state signifying transmission of test data on the particular channel in the current frame or an OFF state signifying no transmission of test data on the particular channel in the current frame.

60. The transmitting entity claim 57, wherein a plurality of channels are concurrently tested, and wherein one pseudo-random number generator and one buffer are associate with each channel to be tested.

61. In a wireless communication system in which a plurality of frames are transmitted, a method for attaining a long-term average value on a duty cycle using a two-state Markov chain, the method comprising:

driving on/off transitions of a test data service option (TDSO) process with a first pseudo-random number generator during a frame period if the frame period is a first length in time; and

driving the on/off transitions with a second pseudo-random number generator during the frame period if the frame period is either a second length in time or a third length in time.

62. The method of claim 61, wherein the first and second pseudo-random number generators provide 24-bits pseudo-random numbers.

63. The method of claim 61, wherein the first length in time is 20 msec.

64. The method of claim 61, wherein the second length in time is 40 msec and the third length in time is 80 msec.

65. The method of claim 61, wherein if the frame period is equal to either the second length in time or the third length in time, the frame is a supplemental channel.

66. The method of claim 61, wherein the long-term average value is configurable.

67. A method of exchanging test parameter values between a remote terminal and a base station in a wireless communication system, the method comprising:

sending proposed test parameter values from the remote terminal to the base station; and

receiving a service option control message from the base station rejecting or negatively acknowledging the proposed test parameter values.

68. A method of constructing a circular buffer storing a plurality of maximum-rate frames transmitted on a particular channel in a wireless communication system, the method comprising:

constructing data for the circular buffer from iterations of a pseudo-random number generator a plurality of times for each test interval; and

using a set of bits from a number generated by the pseudo-random number generator to indicate a byte offset to determine a starting position in the circular buffer from which to build one or more data blocks for a particular frame period.

69. The method of claim 68, wherein the pseudo-random number generator is a 31-bit pseudo-random number generator.

70. The method of claim 68, wherein the set of bits is obtained by

extracting 24 most significant bits of number generated by the pseudo-random number generator, and

extracting six least significant bits of the 24 most significant bits.

71. The method of claim 68, wherein the test interval is defined to coincide with a synchronization frame of the channel.

72. The method of claim 71, wherein the test interval has a duration of 10.24 seconds.