OFDM Modulation Device Dynamic Subcarrier Adjustment
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Solution Overview
Problem
Existing OFDM systems face inefficiencies as the number of subcarriers cannot be adjusted based on changing communication use, leading to wasted resources when transmitting small-capacity control signals.
Innovation Solution
An OFDM modulation device that includes a communication use specifying unit to determine the communication use, a header generating unit to store this information, and an inverse fast Fourier transform unit that adjusts the size of the transform based on the communication use, allowing for dynamic adjustment of the number of subcarriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a fixed number of subcarriers is used for all communication uses, then the system structure is simple and stable, but resource waste occurs when transmitting small-capacity control signals
Solution Approach 1:
The patent applies dynamics by making the number of subcarriers adjustable based on communication use. The inverse fast Fourier transform unit executes transforms of different sizes depending on whether the communication is for control or information, allowing the system to adapt the number of subcarriers dynamically rather than using a fixed number, thereby reducing resource waste for control signals.
Solution Approach 2:
The patent changes the parameter of the number of subcarriers based on communication use. By specifying communication use (control or information) and adjusting the inverse fast Fourier transform size accordingly, the system modifies the subcarrier count parameter to match the actual data transmission needs, eliminating the waste of transmitting unused subcarriers.
2Productivity
If the number of subcarriers is reduced for control signals, then resource efficiency improves, but the system loses flexibility to handle different communication capacities
Solution Approach 1:
The system dynamically adjusts the number of subcarriers based on the specified communication use. For control signals, fewer subcarriers are used to improve resource efficiency, while for information transmission, more subcarriers are allocated to maintain flexibility and handling capability for different communication capacities.
Solution Approach 2:
The patent changes the subcarrier parameter according to communication requirements. The inverse fast Fourier transform unit executes transforms of different sizes based on whether the communication is for control or information, allowing the system to optimize resource efficiency for control while maintaining flexibility for information transmission.
3Productivity
If unused subcarriers are transmitted simultaneously with allocated subcarriers, then the transmission structure is simple, but communication efficiency deteriorates
Solution Approach 1:
The patent extracts only the necessary subcarriers for transmission based on communication use. For control signals, only the required number of subcarriers are transmitted without including unused ones, thereby improving communication efficiency by eliminating the transmission of redundant data while maintaining a relatively simple transmission structure.
Solution Approach 2:
The transmission structure becomes dynamic by adjusting the number of transmitted subcarriers according to communication use. The system transmits only the necessary subcarriers for each communication type, improving efficiency while the underlying framework remains structured and manageable.
Data Source
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AI summary
An OFDM modulation device (1) includes a communication use specifying unit (14) to specify a communication use of a communication frame, a header generating unit (15) to generate a header of the communication frame in which communication use specifying information indicating the communication use specified by the communication use specifying unit (14) is stored, a payload generating unit (16) to generate a payload of the communication frame, and an inverse fast Fourier transform unit (11) to generate a communication frame of time domain by executing an inverse fast Fourier transform of a size corresponding to the communication use specified by the communication use specifying unit (14) on data of frequency domain including the header generated by the header generating unit (15) and the payload generated by the payload generating unit (16).