Mobile Terminal Test Device Frequency Variable Filter
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Solution Overview
Problem
The existing method for measuring out-of-band blocking performance in mobile terminals with carrier aggregation schemes is inefficient due to the need for multiple filters and lengthy measurement times, especially when dealing with multiple downlink frequency bands.
Innovation Solution
A mobile terminal test device and method that simultaneously outputs multiple downlink signals and uses a frequency variable filter to suppress spurious components, allowing for collective throughput measurement across all downlink signals, with re-measurement only for signals not meeting the defined value, and switching the interference signal frequency when all meet the criteria.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple frequency variable filters are prepared for each downlink frequency band to suppress spurious components, then the receiver performance measurement accuracy is improved, but the device complexity and cost increase
Solution Approach 1:
The patent combines multiple downlink signals and interference signals into a single composite signal for transmission to the mobile terminal. Instead of using separate filters for each frequency band, the system merges the signal paths and uses a single frequency variable filter that can be dynamically adjusted to suppress spurious components across different bands, thereby reducing device complexity while maintaining measurement accuracy
Solution Approach 2:
The patent employs a frequency variable filter whose suppression frequency can be dynamically changed according to the interference signal frequency. This dynamic adjustment allows a single filter to replace multiple fixed-frequency filters, reducing system complexity while maintaining the ability to suppress spurious components across different downlink frequency bands
2Measurement precision
If sequential measurement is performed for each downlink frequency band with filter frequency adjustment, then the measurement accuracy is maintained, but the measurement time increases
Solution Approach 1:
The patent measures throughputs for multiple downlink signals simultaneously by combining them into a single composite signal transmitted to the mobile terminal. This eliminates the need for sequential measurement and filter reconfiguration for each frequency band, significantly reducing measurement time while maintaining accurate throughput measurement for all downlink signals
Solution Approach 2:
The patent enables continuous throughput measurement across multiple downlink frequency bands by maintaining a continuous composite signal transmission. Instead of interrupting measurements to adjust filter frequencies between bands, the system continuously transmits the combined signal and measures throughputs simultaneously, eliminating idle time and maintaining productive measurement action throughout the process
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces measurement time by allowing collective throughput measurement across all interference signal frequencies, achieving efficient and cost-effective testing with a simpler system configuration compared to traditional methods.
Implementation Method 1
a filter that suppresses a signal component in a downlink frequency band from an output of the signal generator
Data Source
AI summary
Downlink signals output from a transmission and reception unit are combined with an interference signal of a CW, a resultant signal is applied to a mobile terminal, throughputs for respective interference signal frequencies for the downlink signals are collectively measured, a signal suppression band of the filter is fitted to a frequency band of the downlink signal determined not to reach a defined value, and re-measurement and re-determination of the throughput for the downlink signal among the collectively measured throughputs are performed. In a case where throughputs collectively measured at a certain interference signal frequency are equal to or greater than the defined value and a case where re-measured throughputs of all the downlink signals are equal to or greater than the defined value, the interference signal frequency is switched to the next interference signal frequency, and collective throughput measurement is performed.