Over-the-air Radio Test System Channel Equalization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current wireless test setups for devices under test are sensitive to the relative position of antennas, leading to suboptimal performance and inability to replicate the characteristics of conducted tests, especially in non-conducted setups like over-the-air testing.

Innovation Solution

A radio test system with a signal generation unit, antenna array, control and analyzing unit, and over-the-air adapter that adapts downlink signals using a channel matrix to equalize the over-the-air transmission channel, simulating a base station environment and allowing for deterministic protocol testing similar to cable connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a wireless test setup is used to provide a realistic testing environment, then the testing realism is improved, but the sensitivity to relative antenna position deteriorates

Engineering Contradiction:
Improvetesting realismVSAvoidmeasurement stability
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the power level of the radio test system based on previously determined performance characteristics. This compensates for signal path losses in the wireless environment and reduces sensitivity to antenna position variations, thereby maintaining measurement stability while preserving testing realism

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements preliminary action by determining performance characteristics of the device under test before conducting the actual wireless tests. These pre-determined characteristics are then used to adapt power levels during testing, which compensates for wireless environment effects and reduces position sensitivity

Inventive Principle:
Principle #10Preliminary action

2Loss of energy

If power level adaptation is used to compensate signal path losses, then the signal loss compensation is improved, but other wireless environment influences remain unaddressed

Engineering Contradiction:
Improvesignal path lossVSAvoidcomprehensive compensation
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent implements feedback by continuously measuring the actual transmission channel characteristics during wireless tests and using this information to adapt the power level in real-time. This closed-loop approach not only compensates for signal path losses but also addresses other wireless environment influences by responding to actual measured conditions

Inventive Principle:
Principle #23Feedback

3Difficulty of detecting and measuring

If additional antennas are switched on to simplify channel matrix inversion, then the mathematical determination is improved, but the device complexity increases

Engineering Contradiction:
Improvechannel matrix inversionVSAvoidantenna configuration
Core Design Contradiction:
Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the antenna configuration adaptable - additional antennas are switched on or off based on the specific testing requirements and channel conditions. This dynamic reconfiguration simplifies channel matrix inversion when needed while avoiding unnecessary complexity for other test scenarios, achieving optimal balance between mathematical determination ease and device complexity

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3399674B1Radio test system and method for testing a device under test
Publication Date: 2022.03.02 ROHDE & SCHWARZ GMBH & CO KG
  • EP3399674B1 patent drawingFigure 1
  • EP3399674B1 patent drawingFigure 2

AI summary

A radio test system (10) for testing a device under test (12) is described, comprising a signal generation unit (14) configured to generate a downlink signal to be transmitted to the device under test (12) for over-the-air testing. The radio test system (10) has at least one antenna (18) configured to transmit the downlink signal via an over-the-air transmission channel (42) to the device under test (12). Further, a receiver (30) is provided that is configured to receive a response signal via the over-the-air transmission channel (42) from the device under test (12). In addition, the radio test system (10) has at least one over-the-air adapter (44) that is connected to the signal generation unit (14) wherein the over-the-air adapter (44) is configured to adapt the downlink signal to be transmitted such that the over-the-air transmission channel (42) is equalized. Further, a method for testing a device under test (12) is described.