Tools for design and analysis of over-the-air test systems with channel model emulation capabilities

• US 8,793,093 B2
• Filed: 04/27/2011
• Issued: 07/29/2014
• Est. Priority Date: 04/29/2010
• Status: Expired due to Fees

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Mow, Matt A., Niu, Bo, Schlub, Robert W., Caballero, Ruben
• Primary Examiner(s): Teixeira Moffat, Jonathan C
• Assistant Examiner(s): Casey, Liam R
• Application Number:
  US13/095,656
• Publication Number:
  US 20110270567A1
• Time in Patent Office: 1,189 Days
• Field of Search: 702/120, 702/108, 702/109, 455/67.12, 455/67.14
• US Class Current: 702/108
• CPC Class Codes: G01R 29/0821 rooms and test sites therefor, e.g. anechoic chambers, open field sites or TEM cells for testing antennas G01R29/105
• CPC Class Codes: G01R 29/10 Radiation diagrams of antennas
• CPC Class Codes: H04B 17/0087 using auxiliary channels or channel simulators
• CPC Class Codes: H04B 17/391 Modelling the propagation channel
• CPC Class Codes: H04B 7/0413 MIMO systems

Abstract

A wireless electronic device may serve as a device under test in a test system. The test system may include an array of over-the-air antennas that can be used in performing over-the-air wireless tests on the device under test (DUT). A channel model may be used in modeling a multiple-input-multiple-output (MIMO) channel between a multi-antenna wireless base station and a multi-antenna DUT. The test system may be configured to perform over-the-air tests that emulate the channel model. A design and analysis tool may be used to identify an optimum over-the-air test system setup. The tool may be used in converting a geometric model to a stochastic model for performing conducted tests. The tool may be used in converting a stochastic model to a geometric model and then further convert the geometric model to an over-the-air emulated stochastic model. The over-the-air emulated stochastic model may be used in performing conducted tests.

Claims

1. A method for using a multiple-input-multiple-output over-the-air test system design and analysis tool that is implemented on computing equipment in identifying over-the-air test system settings to use when emulating a channel model with an over-the-air test system, the method comprising:

with the computing equipment, obtaining channel model parameters for the channel model, wherein the channel model parameters comprise attributes of a plurality of signal clusters;

with the computing equipment, obtaining device-under-test parameters for a device under test to be tested using the over-the-air test system; and

with the computing equipment, producing the over-the-air test system settings based on the obtained channel model parameters and the obtained device under test parameters, wherein producing the over-the-air test system settings comprises computing a theoretical spatial correlation value of the channel model and computing an over-the-air spatial correlation value of emulation of the channel model with the over-the-air test system, wherein the theoretical spatial correlation value and the over-the-air spatial correlation value each account for the plurality of signal clusters.

2. The method defined in claim 1 wherein obtaining the channel model parameters comprises obtaining a device under test velocity vector.

3. The method defined in claim 1 wherein obtaining the channel model parameters comprises obtaining a distance between a base station antenna element and a reference base station antenna element.

4. The method defined in claim 1 wherein the device under test comprises a number of antennas and wherein obtaining the device-under-test parameters comprises obtaining a count of the number of antennas in the device under test.

5. The method defined in claim 1 further comprising:

with the computing equipment, obtaining over-the-air test system constraints for the over-the-air test system.

6. The method defined in claim 5 wherein obtaining the over-the-air test system constraints comprises obtaining a count of how many over-the-air antennas are to be used in the over-the-air test system.

7. The method defined in claim 6 wherein producing the over-the-air test system settings further comprises producing the over-the-air test system settings based on the over-the-air test system constraints.

12. The method of claim 1, further comprising determining, with the computing equipment, a difference between the theoretical spatial correlation value and the over-the-air spatial correlation value.

13. The method of claim 1, wherein the producing the over-the-air test system settings further comprises minimizing a cost function that is based on a difference between the theoretical spatial correlation value and the over-the-air spatial correlation value.

8. A method for using a multiple-input-multiple-output over-the-air test system design and analysis tool that is implemented on computing equipment in identifying over-the-air test system settings to use when emulating a channel model with an over-the-air test system, the method comprising:

with the computing equipment, computing performance parameters associated with the channel model, wherein the computing the performance parameters comprises computing a theoretical spatial correlation value of the channel model and computing an over-the-air spatial correlation value of emulation of the channel model with the over-the-air test system, wherein the theoretical spatial correlation value and the over-the-air spatial correlation value each account for a plurality of signal clusters of the channel model; and

with the computing equipment, computing cost-function-derived over-the-air test system settings based on the performance parameters, wherein computing the cost-function-derived over-the-air test system settings comprises

minimizing a cost function that is based on a difference between the theoretical spatial correlation value and the over-the-air spatial correlation value.

9. The method defined in claim 8, wherein computing the performance parameters comprises computing at least one power azimuth spectrum value.

11. The method defined in claim 8, further comprising:

with the computing equipment, obtaining over-the-air test system constraints for the over-the-air test system; and

with the computing equipment, obtaining device-under-test parameters for a device under test to be tested using the over-the-air test system.

10. A method for using a multiple-input-multiple-output over-the-air test system design and analysis tool that is implemented on computing equipment in identifying over-the-air test system settings to use when emulating a channel model with an over-the-air test system, the method comprising:

with the computing equipment, computing performance parameters associated with the channel model, wherein the computing the performance parameters comprises computing a theoretical power azimuth spectrum value of the channel model and computing an over-the-air power azimuth spectrum value of emulation of the channel model with the over-the-air test system, wherein the theoretical power azimuth spectrum value and the over-the-air power azimuth spectrum value each account for a plurality of signal clusters of the channel model; and

with the computing equipment, computing a cost-function-derived over-the-air test system settings based on the performance parameters, wherein computing the cost-function-derived over-the-air test system settings comprises

minimizing a cost function that is based on a difference between the theoretical power azimuth spectrum value and the over-the-air power azimuth spectrum value.