Transmission performance measurement and use thereof

• US 6,754,475 B1
• Filed: 06/28/2002
• Issued: 06/22/2004
• Est. Priority Date: 06/28/2002
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Rohani, Kamyar, Harrison, Robert Mark, Gummadi, Srikanth
• Primary Examiner(s): Vuong, Quochien B.
• Application Number:
  US10/185,974
• Time in Patent Office: 725 Days
• Field of Search: 455/69, 455/115.1, 455/115.3, 455/115.4, 455/504, 455/522, 455/561, 455/562.1, 455/67.11, 455/67.13, 455/277.1, 455/423, 455/424, 370/342, 370/345, 370/347, 370/252
• US Class Current: 455/115.1
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication

Abstract

A method for and wireless communications unit adapted for measuring transmission performance for a signal emanating from an antenna is discussed. The wireless communications unit includes a receiver for receiving the signal in a first and a second time interval to provide, respectively, a first and a second signal; and a channel processor for assessing a relative channel metric corresponding to the first and second signal, the relative channel metric indicative of the transmission performance of a transmission mode. A corresponding method and base transmitter is also arranged and adapted for adjusting a transmission mode based on measured transmission performance and includes a transmitter for sending the signal in the first and second time interval and a base channel processor for determining a channel metric corresponding to the first and second signal, the channel metric indicative of the transmission performance; the transmitter further sending a control signal corresponding to the transmission mode adjusted according to the transmission performance.

Claims

1. A method of measuring transmission performance for a signal emanating from an antenna, the method including:

receiving the signal in a first time interval and in a second time interval to provide, respectively, a first channel metric and a second channel metric;

assessing a relative channel metric corresponding to said first channel metric and said second channel metric, said relative channel metric indicative of the transmission performance of a transmission mode wherein the transmission mode is one of a plurality of transmission modes; and

sending an information signal corresponding to said relative channel metric and receiving a control signal with a predetermined control component, said control signal including a pilot signal adjusted in a predetermined manner.

2. The method of claim 1 further including comparing said relative channel metric to a threshold to provide a comparison and, responsive to said comparison, sending said information signal further corresponding to said transmission mode.

3. The method of claim 1 wherein said receiving said control signal further comprises receiving a control signal corresponding to another transmission mode wherein said another transmission mode is selected according to the transmission performance.

4. The method of claim 1 wherein said assessing said relative channel metric further includes assessing a phase difference between a first and a second channel emanating from a first and a second element of the antenna.

5. The method of claim 1 wherein said assessing said relative channel metric further includes determining a first and a second adaptive array weights for, respectively, said first time interval and said second time interval.

6. The method of claim 1 wherein said relative channel metric further includes determining a metric corresponding to a number of information bits within said first time interval.

7. The method of claim 6 wherein said relative channel metric further includes determining a metric corresponding to said number of information bits and a second number of information bits.

8. The method of claim 1 further including sending an information signal corresponding to said first channel metric.

9. A method of measuring transmission performance for a signal emanating from an antenna, the method including:

receiving the signal in a first time interval and in a second time interval to provide, respectively, a first channel metric and a second channel metric; and

assessing a relative channel metric corresponding to said first channel metric and said second channel metric, said relative channel metric indicative of the transmission performance of a transmission mode wherein the transmission mode is one of a plurality of transmission modes,

wherein said assessing said relative channel metric further includes determining a metric corresponding to adaptive array weights for said first time interval and an alternative transmission mode.

10. The method of claim 9 wherein said alternative transmission mode includes operating as one of a non-adaptive transmit antenna array, a single transmit antenna, and a multiple input multiple output antenna.

11. The method of claim 9 wherein said relative channel metric further includes determining a metric corresponding to a number of information bits within said first time interval.

12. The method of claim 11 wherein said relative channel metric further includes determining a metric corresponding to said number of information bits and a second number of information bits.

13. A method of adjusting a transmission mode based on measured transmission performance for a signal emanating from an antenna, the method including:

sending the signal in a first time interval and in a second time interval to provide, respectively, a first signal and a second signal;

determining a channel metric corresponding to said first signal and said second signal, said channel metric indicative of the transmission performance;

sending a control signal corresponding to the transmission mode wherein the transmission mode is adjusted according to the transmission performance, said control signal further comprising a predetermined control component included in a pilot signal adjusted in a predetermined manner.

14. The method of claim 13 further including processing said channel metric to provide a relative channel metric, comparing said relative channel metric to a threshold to provide a comparison and, responsive to said comparison, sending said control signal corresponding to said transmission mode.

15. The method of claim 13 wherein said channel metric is a relative channel metric corresponding to an assessment of a phase difference between a first and a second channel emanating from the antenna.

16. The method of claim 13 wherein said channel metric corresponds to adaptive array weights for said first time interval and said second time interval.

17. The method of claim 13 wherein said channel metric further corresponds to a number of information bits within said first time interval.

18. The method of claim 17 wherein said channel metric further corresponds to said number of information bits and a second number of information bits.

19. The method of claim 13 wherein said determining said channel metric includes receiving an information signal corresponding to said first signal and said second signal.

20. The method of claim 13 wherein said determining said channel metric further includes receiving a third signal and measuring said third signal.

21. A method of adjusting a transmission mode based on measured transmission performance for a signal emanating from an antenna, the method including:

sending the signal in a first time interval and in a second time interval to provide, respectively, a first signal and a second signal;

determining a channel metric corresponding to said first signal and said second signal, said channel metric indicative of the transmission performance, wherein said channel metric further corresponds to adaptive array weights for said first time interval and an alternative transmission mode; and

sending a control signal corresponding to the transmission mode wherein the transmission mode is adjusted according to the transmission performance.

22. The method of claim 21 wherein said alternative transmission mode further includes operating as one of a non-adaptive transmit antenna array, a single antenna, and a multiple input multiple output antenna.

23. The method of claim 21 wherein said channel metric further corresponds to a number of information bits within said first time interval.

24. The method of claim 23 wherein said channel metric further corresponds to said number of information bits and a second number of information bits.

25. A wireless communications unit adapted for measuring transmission performance for a signal emanating from an antenna, the wireless communications unit comprising in combination:

a receiver for receiving the signal in a first time interval and in a second time interval to provide, respectively, a first signal and a second signal; and

a channel processor for assessing a relative channel metric corresponding to said first signal and said second signal, said relative channel metric indicative of the transmission performance of a transmission mode, wherein the transmission mode is one of a plurality of transmission modes and the relative channel metric corresponds to adaptive array weights for said first time interval and an alternative transmission mode.

26. The wireless communications unit of claim 25 wherein said channel processor further compares said relative channel metric to a threshold to provide a comparison and, said wireless communications unit further includes a transmitter for sending, responsive to said comparison, an information signal corresponding to said transmission mode.

27. The wireless communications unit of claim 25 further including a transmitter for sending an information signal corresponding to said relative channel metric and wherein said receiver further receives a control signal corresponding to another transmission mode wherein said another transmission mode is adjusted according to the transmission performance.

28. The wireless communications unit of claim 25 wherein said channel processor assesses a phase difference between a first and a second channel emanating from a first and a second element of the antenna.

29. A base transmitter arranged and adapted for adjusting a transmission mode based on measured transmission performance for a signal emanating from an antenna, the base transmitter comprising in combination:

a transmitter for sending the signal in a first time interval and in a second time interval to provide, respectively, a first signal and a second signal;

a base channel processor for determining a channel metric corresponding to said first signal and said second signal, said channel metric indicative of the transmission performance and corresponding to adaptive array weights for said first time interval and an alternative transmission mode; and

said transmitter further for sending a control signal corresponding to the transmission mode wherein the transmission mode is adjusted according to the transmission performance.

30. The base transmitter of claim 29 further including a receiver for receiving an information signal corresponding to said first signal and said second signal and wherein said base channel processor further determines a relative channel metric based on said information signal, compares said relative channel metric to a threshold to provide a comparison and said transmitter, responsive to said comparison, sends said control signal corresponding to said transmission mode.

31. The base transmitter of claim 29 wherein said transmitter further sends said control signal including a signal with a predetermined control component adjusted in a predetermined manner.

32. The base transmitter of claim 29 wherein said base channel processor determines said channel metric corresponding to a phase difference between a first and a second channel emanating from the antenna.