Installation technique for a multiple input multiple output (MIMO) wireless communications systems

• US 7,330,697 B1
• Filed: 04/27/2005
• Issued: 02/12/2008
• Est. Priority Date: 04/27/2004
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Piping Hot Networks Ltd. (Motorola Solutions, Inc.)
• Inventors: Carter, Richard A., Clark, Paul, King, Nigel J. R., Strong, Peter N., Bolt, Philip A., Wild, Timothy G., Dean, Gregor R., Spier, Colin H. V., Holmes, Antony C.
• Primary Examiner(s): LE, THANH C
• Application Number:
  US11/115,973
• Time in Patent Office: 1,021 Days
• Field of Search: None
• US Class Current: 455/63.1
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/06 Testing, supervising or monitoring using simulated traffic
• CPC Class Codes: H04W 72/54 based on quality criteria

Abstract

Techniques for facilitating and reducing the costs associated with the installation of a wireless broadband communications system. In one mode of operation, the system employs a first transceiver to identify n channels having the n lowest levels of noise and interference associated therewith by a spectrum management technique. Next, the first transceiver transmits a predetermined code over the n channels to a second transceiver, which attempts to identify the predetermined code within a captured transmission. In the event the code is correctly identified, the second transceiver measures a noise and/or interference level associated with the corresponding channels. The channel having the lowest measured noise and interference level is then selected for use in system installation.

Claims

1. A method of installing a wireless communications system, the wireless communications system including first and second transceivers operable to transmit and receive signals over a plurality of communications channels, each channel having at least one of a noise level and an interference level associated therewith, comprising the steps of:

identifying a predetermined number n of the plurality of channels having the n lowest levels of noise and interference associated therewith by a spectrum management technique, the predetermined number n being greater than one, the identification of the n channels being performed by the first transceiver;

transmitting a predetermined code over the n identified channels to the second transceiver by the first transceiver;

monitoring at least the predetermined number n of the plurality of channels by the second transceiver;

in the event the transmission by the first transceiver is captured on at least one of the n channels monitored by the second transceiver, identifying the predetermined code within the transmission over the at least one of the n channels by the second transceiver;

in the event the predetermined code is correctly identified within the transmission over the at least one of the n channels by the second transceiver, measuring at least one of a noise level and an interference level associated with the at least one of the n channels by the second transceiver; and

selecting a respective one of the at least one of the n channels having the lowest measured noise and interference level for use in system installation.

2. The method of claim 1 wherein the spectrum management technique includes:

periodically measuring at least one of a noise level and an interference level associated with each one of the plurality of channels;

generating a histogram of the noise and interference level measurements associated with each channel, each histogram comprising a plurality of bins, each bin corresponding to a predetermined range of noise and interference levels associated with the respective channel;

determining a noise and interference level estimate for each channel as a predetermined percentile of the histogram of measured noise and interference levels associated with the respective channel; and

identifying the predetermined number n of the plurality of channels having the n lowest noise and interference level estimates.

3. The method of claim 2 wherein the predetermined range of noise and interference levels corresponding to each bin is approximately equal to 1 dB.

4. The method of claim 2 wherein the predetermined percentile of the histogram of measured noise and interference levels associated with the respective channels is the 99.9 percentile.

5. The method of claim 1 wherein the transmitting step includes sequentially transmitting the predetermined code over the n identified channels to the second transceiver by the first transceiver.

6. The method of claim 1 further including the step of generating the predetermined code by inputting a Machine Address Code (MAC) address associated with the first transceiver to a predetermined Hash function to obtain the predetermined code.

7. The method of claim 1 further including the step of transmitting the noise and interference level measurements associated with the at least one of the n channels to the first transceiver by the second transceiver.

8. The method of claim 7 wherein the step of selecting the respective one of the at least one of the n channels having the lowest measured noise and interference level is performed by the first transceiver.

9. The method of claim 1 wherein the step of selecting the respective one of the at least one of the n channels having the lowest measured noise and interference level is performed by the second transceiver.

10. The method of claim 1 wherein the step of transmitting the predetermined code over the n identified channels to the second transceiver by the first transceiver includes employing multiple carrier signals including pilot carrier signals and data carrier signals in an orthogonal frequency division modulation (OFDM) waveform.

11. The method of claim 10 wherein the step of transmitting the predetermined code over the n identified channels to the second transceiver by the first transceiver includes modulating each pilot carrier signal with a predetermined sequence.

12. The method of claim 11 wherein the predetermined sequence comprises a cyclic prefix of one complete OFDM symbol.

13. The method of claim 10 wherein the step of transmitting the predetermined code over the n identified channels to the second transceiver by the first transceiver includes modulating each data carrier signal with the predetermined code.

14. The method of claim 10

wherein the step of transmitting the predetermined code over the n identified channels to the second transceiver by the first transceiver includes modulating each pilot carrier signal with a predetermined sequence, modulating each data carrier signal with the predetermined code, and transmitting the modulated pilot and data carrier signals over the n identified channels, and

further including the step of

obtaining synchronization with the predetermined code by performing a sliding correlation of the modulated pilot and data carrier signals against the predetermined sequence by the second transceiver.

15. The method of claim 1 further including the step of, in the event the predetermined code is correctly identified within the transmission over the at least one of the n channels by the second transceiver, producing a tone audible by a human installer of the system.

16. The method of claim 15 wherein the audible tone is characterized by a non-linear audio transfer characteristic.

17. The method of claim 16 wherein the non-linear audio transfer characteristic is representable by a plot of received signal levels (dBm) versus audio frequency (Hz), and wherein the non-linear audio transfer characteristic is definable on the plot by three substantially linear segments including a first segment within a first range of (−

100 dBm, 300 Hz) to (−

80 dBm, 600 Hz), a second segment within a second range of (−

80 dBm, 600 Hz) to (−

65 dBm, 2000 Hz), and a third segment within a third range of (−

65 dBm, 2000 Hz) to (−

50 dBm, 3000 Hz).

18. The method of claim 15 wherein the audible tone is a substantially continuous audible tone.

19. The method of claim 1 further including the step of, in the event the predetermined code is not correctly identified within the transmission over the at least one of the n channels by the second transceiver, producing a stuttered tone audible by a human installer of the system.

20. The method of claim 19 wherein the stuttered audible tone is defined as being periodically audible for approximately 2 seconds and inaudible for approximately 0.5 seconds.

21. The method of claim 1 further including the step of resetting at least one system parameter to default settings before performing the system installation.

22. The method of claim 21 wherein the at least one system parameter includes IP address information.

23. The method of claim 1 further including the step of resetting at least one system parameter to default settings before performing the system installation.

24. The method of claim 1 further including the steps of

transmitting at least one data signal over the respective selected one of the n channels having the lowest measured noise and interference level by either of the first and second transceivers, and

producing a blinking light visible by a human installer of the system to indicate the transmission of the data signal.

25. The method of claim 1 further including the steps of

receiving at least one data signal over the respective selected one of the n channels having the lowest measured noise and interference level by either of the first and second transceivers, and

producing a blinking light visible by a human installer of the system to indicate the reception of the data signal.

26. The method of claim 1 further including the steps of

loading software into the system prior to system installation, and

in the event the system software is successfully loaded, producing a blinking light visible by a human installer of the system to indicate the successful loading of the software.

27. A circuit for detecting a switch actuation at a distal end of a first cable, comprising:

first circuitry operative to generate a frequency selective short circuit;

a switch connected in series with the first circuitry;

second circuitry operative to generate a frequency selective short circuit;

an oscillator; and

a load, the oscillator and the load being connected in series with the second circuitry,

wherein the first cable comprises at least two conductors, the two conductors being connected across the serially connected first circuitry and the switch at the distal end of the first cable, and the two conductors being connected across the serially connected second circuitry, the oscillator, and the load at a proximal end of the first cable, and

whereby the switch actuation is detected by detecting power in the load.

28. The circuit of claim 27 wherein each of the first and second circuitry includes a capacitor connected in series with an inductor.

29. The circuit of claim 27 wherein the oscillator comprises a 1.5 MHz oscillator.

30. The circuit of claim 27 wherein the first cable comprises an Ethernet cable.

31. The circuit of claim 30 wherein the Ethernet cable is a CAT 5 cable.

32. The circuit of claim 27 further including a second cable having a first end and a second end, the first end of the second cable being connected to the distal end of the first cable, the second end of the second cable being communicably coupleable to a network.

33. The circuit of claim 32 wherein the second cable comprises an Ethernet cable.

34. The circuit of claim 33 wherein the Ethernet cable is a 100baseT cable.

35. A circuit for indicating transmission of data over a first cable, the indication being provided at a distal end of the first cable, comprising:

first circuitry operative to generate a frequency selective short circuit;

an indicator connected in series with the first circuitry;

second circuitry operative to generate a frequency selective short circuit; and

an oscillator connected in series with the second circuitry,

wherein the first cable comprises at least two conductors, the two conductors being connected across the serially connected first circuitry and the indicator at the distal end of the first cable, and the two conductors being connected across the serially connected second circuitry and the oscillator at a proximal end of the first cable, and

whereby the indication of data transmission is provided by a switching on and off of the oscillator causing a current to flow through the indicator.

36. The circuit of claim 35 wherein each of the first and second circuitry includes a capacitor connected in series with an inductor.

37. The circuit of claim 35 wherein the oscillator comprises a 50 kHz oscillator.

38. The circuit of claim 35 wherein the first cable comprises an Ethernet cable.

39. The circuit of claim 38 wherein the Ethernet cable is a CAT 5 cable.

40. The circuit of claim 35 further including a second cable having a first end and a second end, the first end of the second cable being connected to the distal end of the first cable, the second end of the second cable being communicably coupleable to a network.

41. The circuit of claim 40 wherein the second cable comprises an Ethernet cable.

42. The circuit of claim 41 wherein the Ethernet cable is a 100baseT cable.