Signal Generation Device for Dynamic OFDM Characteristic Simulation
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Solution Overview
Problem
Existing waveform generation devices for mobile communication terminals do not account for changes in amplitude-frequency and phase-frequency characteristics over time, which is crucial for testing terminals designed for wide bandwidth modulation systems like OFDM or OFDMA.
Innovation Solution
A signal generation device that includes sub-carrier generation, time domain conversion, and frequency characteristic calculation means to add amplitude-frequency and phase-frequency characteristics to sub-carriers based on stored data, allowing for signals with dynamic characteristics over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the waveform generation device sets amplitude or phase to a predetermined value, then the device structure remains simple, but it cannot simulate changing amplitude-frequency and phase-frequency characteristics over time
Solution Approach 1:
The patent introduces dynamic characteristics to the waveform generation device by enabling time-varying amplitude and phase adjustments. The frequency characteristic calculation unit dynamically modifies frequency characteristics based on stored data and time information, allowing the device to simulate changing channel conditions over time rather than maintaining fixed characteristics.
Solution Approach 2:
The patent employs preliminary action by pre-storing frequency characteristic data in the frequency characteristic storage unit. This stored data is later retrieved and applied by the frequency characteristic calculation unit when needed, allowing the device to rapidly switch between different characteristic patterns without real-time computation complexity.
2Adaptability or versatility
If the waveform generation device adds frequency characteristic calculation means to simulate changing characteristics, then test comprehensiveness improves, but device complexity increases
Solution Approach 1:
The patent segments the waveform generation function into distinct modular units: sub-carrier generation unit, frequency characteristic storage unit, frequency characteristic calculation unit, and time domain conversion unit. This segmentation allows each component to perform a specific function independently, improving test comprehensiveness while managing complexity through modular design.
Solution Approach 2:
The frequency characteristic calculation unit acts as an intermediary between the sub-carrier generation unit and the time domain conversion unit. It receives sub-carriers, applies stored frequency characteristics based on time information, and outputs modified sub-carriers to the next stage, enabling flexible characteristic modification without redesigning the entire system.
3Manufacturing precision
If the device processes frequency characteristics for each sub-carrier in predetermined time units, then signal accuracy improves, but processing complexity increases
Solution Approach 1:
The patent implements periodic action by processing frequency characteristics in predetermined time units (frames). The frequency characteristic calculation unit periodically updates and applies frequency characteristics to sub-carriers at each frame boundary, ensuring signal accuracy while providing a regular, manageable processing rhythm that reduces overall complexity.
Data Source
AI summary
To provide a mobile communication terminal test device that can generate a signal with amplitude-frequency characteristics or phase-frequency characteristics which are changed over time. A mobile communication terminal test device 10 includes a data generation unit 12 that generates a bit stream, a sub-carrier generation unit 31 that receives bit stream data and performs, for example, predetermined encoding, symbol mapping, or sub-carrier mapping to convert the received data into a plurality of sub-carriers based on an OFDM modulation system, a frequency characteristic storage unit 13 that stores table data for predetermined amplitude-frequency characteristics and phase-frequency characteristics, and a frequency characteristic calculation unit 32 that sets the amplitude and phase of each sub-carrier input from the sub-carrier generation unit 31 on the basis of the table data.