# US 8,787,900 B2 · Methods and systems for testing cell phones with multiple antennas

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- Number: US 8,787,900 B2
- Document ID: US8787900B2
- Status: Granted
- Kind: B2
- Application number: 12/625,180
- Filed: 2009-11-24
- Published: 2011-05-26
- Granted: 2014-07-22
- Earliest claimed: 2009-11-24
- Assignees: Spirent Communications, Inc.
- Applicants: Arashk Mahjoubi Amine; Randy Oltman; Madhusudhan Gurumurthy; Charles Zheng; Joe Willis
- Inventors: Arashk Mahjoubi Amine; Randy Oltman; Madhusudhan Gurumurthy; Charles Zheng; Joe Willis
- Web page: https://patentgrep.com/patent/US8787900B2

## CPC

- H04B 17/0087: {using auxiliary channels or channel simulators}
- H04B 17/3911: {Fading models or fading generators}
- H04B 7/0413: MIMO systems
- H04B 7/0837: {using pre-detection combining (H04B7/0868 takes precedence)}
- H04B: TRANSMISSION

## Abstract

The present invention relates to testing cell phones that simulates network conditions. In particular, it relates to new testing capabilities for simulating changes in correlation characteristics of signal components delivered to a cell phone. Correlation characteristics express changing environmental conditions and physical relationships among antennas in the cell phone and at base stations.

## Claims

### Claim 1

A system used to test a cell phone that uses multiple cell phone antennas, including:
at least one signal feed adapted to be coupled to the cell phone at a location that bypasses the cell phone antennas, whereby the cell phone performs multiple-input/multiple output, abbreviated MIMO, processing of multiple signals from the multiple cell phone antennas;
at least one memory; and
one or more channel generator modules running on one or more processors, coupled to the signal feed and the memory, wherein each channel generator module:
uses at least three correlation data sets stored in the memory to emulate different channel conditions of a propagation channel model (abbreviated “PCM”), the correlation data sets representing time-varying reorientation of the multiple cell phone antennas; and
conditions a test signal with the different channel conditions and passes the conditioned test signal to the signal feed; and
a measurement module running on one or more of the processors, coupled to the signal feed, that measures response of the cell phone to the conditioned test signal.

### Claim 2 (depends on 1)

The system of claim 1, wherein the processors are FPGAs.

### Claim 3 (depends on 2)

The system of claim 2, wherein the correlation data sets represent a plurality of paths between each paring between the multiple base station antennas and the multiple cell phone antennas and subsets of the paths are assigned to respective channel generator modules running on respective ones of the FPGAs.

### Claim 4 (depends on 2)

The system of claim 2, further including a plurality of channel generator modules running on a plurality of the FPGAs and a synchronized time base generator coupled to the channel generator modules to supply a synchronized time base.

### Claim 5 (depends on 2)

The system of claim 2, wherein the channel generator modules or another emulation component emulates fast fading.

### Claim 6 (depends on 2)

The system of claim 2, wherein the channel generator modules or another emulation component emulates shadowing.

### Claim 7 (depends on 2)

The system of claim 2, wherein the channel generator modules or another emulation component emulates channel noise.

### Claim 8 (depends on 2)

The system of claim 2, further including at least eight correlation data sets stored in memory that emulate the different channel conditions of the PCM.

### Claim 9 (depends on 1)

The system of claim 1, wherein the channel generator modules iterate over a plurality of PCMs in a single test.

### Claim 10 (depends on 9)

The system of claim 9, wherein the plurality of PCMs represent the cell phone moving from one environment to another.

### Claim 11 (depends on 9)

The system of claim 9, wherein the plurality of PCMs represent the cell phone moving between first and second base stations.

### Claim 12 (depends on 9)

The system of claim 9, further including as PCMs available for emulation at least Suburban Macro, Urban Macro and Urban Micro models conforming to 3GPP propagation channel models.

### Claim 13 (depends on 9)

The system of claim 9, further including as PCMs available for emulation representing at least indoor office/residential, indoor to outdoor, typical urban micro-cell, bad urban micro-cell, large indoor hall, outdoor to indoor microcell, line of sight feeder for rooftop to rooftop, line of sight feeder for street-level to street-level, line of sight feeder for below rooftop to street-level, non-line of sight feeder for above rooftop to street-level, non-line of sight fixed feeder links for one terminal at near rooftop, suburban, typical urban macro-cell, bad urban macro-cell, outdoor to indoor macro-cell, rural macro-cell, and moving network models in conformance with WINNER models.

### Claim 14

A method of testing new cell phone designs that use multiple cell phone antennas, including:
coupling at least one signal feed to a cell phone at a location that bypasses the cell phone antennas, whereby the cell phone performs multiple-input/multiple output, abbreviated MIMO, processing of multiple signals from the multiple cell phone antennas; and
conducting a test using one or more channel generator modules running on one or more processors, including:
using at least three correlation data sets stored in memory to emulate different channel conditions of a propagation channel model (abbreviated “PCMs”), the correlation data sets representing time-varying reorientation of the multiple cell phone antennas; and
applying each of the different channel conditions to a test signal that is fed to the cell phone on the signal feed; and
measuring response of the cell phone to the different channel conditions.

### Claim 15 (depends on 14)

The method of claim 14, further including emulating a plurality of PCMs in a single test.

### Claim 16 (depends on 15)

The method of claim 15, further including choosing the emulated PCMs from a set including environments representing at least Suburban Macro, Urban Macro and Urban Micro 3GPP propagation channel models.

### Claim 17 (depends on 14)

The method of claim 14, further including choosing one or more PCMs to emulate from a set including environments representing at least indoor office/ residential, indoor to outdoor, typical urban micro-cell, bad urban micro-cell, large indoor hall, outdoor to indoor microcell, line of sight feeder for rooftop to rooftop, line of sight feeder for street-level to street-level, line of sight feeder for below rooftop to street-level, non-line of sight feeder for above rooftop to street-level, non-line of sight fixed feeder links for one terminal at near rooftop, suburban, typical urban macro-cell, bad urban macro-cell, outdoor to indoor macro-cell, rural macro-cell, and moving network.

### Claim 18 (depends on 14)

The method of claim 14, further including changing emulated propagation channel models during a single test, the changed PCMs emulating the cell phone moving from one environment to another.

### Claim 19 (depends on 14)

The method of claim 14, further including using a plurality of channel generator modules running on respective ones of the processors, supplying a synchronized time base to the channel generator modules and applying synchronized channel condition contributions from the channel generator modules to the test signal.

### Claim 20 (depends on 14)

The method of claim 14, wherein emulating the different channel conditions includes emulating multipathing between pairs of base station antennas and the cell phone antennas.

### Claim 21 (depends on 14)

The method of claim 14, wherein emulating the different channel conditions includes representing multiple base stations that each have multiple base station antennas and emulating movement of the cell phone between a first base station and a second base station.

### Claim 22 (depends on 14)

The method of claim 14, wherein emulating the different channel conditions includes emulating fast fading.

### Claim 23 (depends on 14)

The method of claim 14, wherein emulating the different channel conditions includes emulating shadowing.

### Claim 24 (depends on 14)

The method of claim 14, wherein emulating the different channel conditions includes emulating channel noise.

### Claim 25 (depends on 14)

The method of claim 14, wherein emulating the different channel conditions includes using at least eight correlation data sets stored in memory to emulate the different channel conditions of the PCM.