Adaptive orthogonal channel noise source

• US 6,873,844 B2
• Filed: 03/28/2002
• Issued: 03/29/2005
• Est. Priority Date: 03/28/2002
• Status: Active Grant

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Najib, Muhieddin, Ang, Swee-Seng, Jager, Frank
• Primary Examiner(s): Chin, Vivian
• Assistant Examiner(s): Persino, Raymond B.
• Application Number:
  US10/109,546
• Publication Number:
  US 20040203418A1
• Time in Patent Office: 1,097 Days
• Field of Search: 455/423, 455/424, 455/67.11, 455/67.14, 455/446, 455/453
• US Class Current: 455/424
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level

Abstract

A method of adapting the Orthogonal Channel Noise Source (OCNS) for optimization and acceptance testing of a CDMA based wireless network under load conditions is disclosed. According to an embodiment of the invention, a test loading level (for example, 80%) and performance requirements are established for a plurality of Base-station Transceiver Subsystems (BTS). The subsystems then transmit any required overhead power plus sufficient OCNS power such that the total output level of the BTS power amplifier is at the selected test level (e.g. 80%). As a mobile unit moves within range of a BTS and requests access, the unit'"'"'s power requirement is determined based on the requested data rate. The OCNS power level of the new BTS is then adjusted or lowered by an amount equal to the detected power requirements to allow access to the mobile unit. The BTS then establishes a communication link with the mobile unit. Thus, the total power output of the tower under test is maintained at a pre-selected level such as for example 80%.

Claims

1. A method of testing a wireless communication system comprising the steps of:

selecting a test loading level for a BTS (“

Base-station Transceiver Subsystem”

) power output, said selected loading level including an OCNS (Orthogonal Channel Noise Source) portion and a portion representing the power requirements of connected mobile units;

determining the power requirements of a selected mobile unit;

adjusting said OCNS portion of said BTS power output by an amount equal to said determined power requirements of said selected mobile unit; and

establishing a communication link between said BTS and said selected mobile unit such that said selected test loading level is maintained.

2. The method of claim 1 further comprising the steps of:

determining the power requirements of another selected mobile unit;

further adjusting said OCNS portion of said BTS power output by an amount equal to said determined power requirements of said another selected mobile unit; and

establishing communications between said BTS and said another selected mobile unit such that said selected test loading level is maintained.

3. The method of claim 2 further comprising the steps of terminating said communications between said BTS and said selected mobile unit;

and

readjusting said OCNS portion of said BTS power output such that said selected test level loading is maintained.

4. The method of claim 2 wherein said wireless communication system is a CDMA based system.

5. The method of claim 2 wherein said selecting step comprises selecting a range of test loading levels and further comprising repeating said determining, adjusting and establishing steps for each of said test loading levels.

6. The method of claim 1 further comprising the steps of:

terminating said communications between said BTS and said selected mobile unit; and

readjusting said OCNS portion of said BTS power output such that said selected test level loading is maintained.

7. The method of claim 1 wherein said power requirements of said selected mobile unit varies with the transmission data rate of said unit.

8. The method of claim 1 wherein said selected mobile unit is in communication with another BTS and said step of determining comprises the steps of measuring the power requirements of said selected mobile unit as a function of the required signal to noise ratio and the requested data rate between another BTS and said first selected mobile unit.

9. The method of claim 1 wherein said wireless communication system is a CDMA based system.

10. The method of claim 1 wherein said selecting step comprises selecting a range of test loading levels and further comprising repeating said determining, adjusting and establishing steps for each of said test loading levels.

11. The method of claim 1 further comprising the step of receiving a request for service from said selected mobile unit prior to said adjusting step.

12. A method of testing a wireless communication system comprising a multiplicity of BTS units spaced over an area and each BTS unit providing a pattern of coverage, said method comprising the steps of:

selecting a test loading level for the power output of each one of said multiplicity of BTS units, said selected loading level of each BTS unit including an OCNS (Orthogonal Channel Noise Source) portion and a portion representing the power requirements of connected mobile units;

establishing a communication link between a first one of said multiplicity of BTS units and a selected mobile unit located within the pattern of coverage of said first one of said multiplicity;

transmitting data between said selected mobile unit and said first one of said multiplicity;

moving said selected mobile unit into the pattern of coverage of a second one of said multiplicity of BTS units;

determining the power requirements of said selected mobile unit;

adjusting said OCNS portion of said power output of said second one of said multiplicity of BTS units by an amount equal to said determined power requirements of said selected mobile unit; and

establishing a communication link between said selected mobile unit and said second one of said multiplicity of said BTS unit and said second one of said multiplicity of said BTS units such that said selected test loading level is maintained.

13. The method of claim 12 further comprising the steps of:

determining the power requirements of another selected mobile unit;

further adjusting said OCNS portion of said power output of said second one of said multiplicity of BTS units by an amount equal to said determined power requirements of said second selected mobile unit; and

establishing a communication link between said second one of said BTS units and said another selected mobile unit such that said selected test loading level is maintained.

14. The method of claim 12 further comprising the step of said second one of said multiplicity of BTS units receiving a request for service from said selected mobile unit prior to said adjusting step.

15. The method of claim 12 further comprising the steps of:

terminating said communication link between said selected mobile unit and said first one of said multiplicity of BTS units; and

readjusting said OCNS portion of power output of said first one of multiplicity of BTS units such that said selected test loading is maintained.

16. The method of claim 12 wherein said communication system is a CDMA based system.

17. A method of testing a wireless communication system comprising the steps of:

selecting a test loading level for power output of a BTS unit, said selected loading level including an OCNS portion and a portion representing the power requirements of connected mobile units;

determining the power requirements of a plurality of mobile units;

adjusting said OCNS portion of power output of said BTS unit by an amount equal to said determined power requirements of one of said plurality of mobile units;

establishing a communication link between said BTS unit and said one of said plurality of mobile units; and

repeating said adjusting step and said repeating step for other ones of said plurality of mobile units.