OvXDM Modulation Virtual Cutoff for Transmission Rate
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Solution Overview
Problem
In overlapped multiplexing systems, multiplexing waveforms often exhibit a 'tailing' phenomenon, leading to low transmission rates due to low energy in the modulation domain, while maintaining good performance in corresponding domains, creating a contradiction between transmission rate and performance.
Innovation Solution
A modulation method and apparatus for an OvXDM system that virtually cuts off the initial envelope waveform's tail, calculating a modulation-domain shift interval to improve symbol width and transmission rate, while retaining the waveform's performance by not actually cutting off the tail, allowing shifting and superimposition to maintain good performance in corresponding domains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the multiplexing waveform is subject to tailing in the modulation domain, then the waveform has good performance in the corresponding domain (small width, fast side lobe attenuation), but the transmission rate is reduced
Solution Approach 1:
The patent extracts and removes the tailing portion of the multiplexing waveform in the modulation domain. By identifying the tail length based on energy thresholds and subtracting it from the original waveform, the system eliminates the low-energy tailing segment that reduces transmission rate while preserving the main waveform body that provides good performance characteristics.
Solution Approach 2:
The patent performs preliminary processing on the multiplexing waveform before transmission by pre-calculating and removing the tailing portion. The tail length is determined in advance based on energy thresholds, and the virtual cutoff is applied before the waveform is used for modulation, thereby preventing the transmission rate reduction caused by tailing while maintaining waveform performance.
2Productivity
If the tail length of the initial envelope waveform is reduced to improve transmission rate, then the symbol width decreases and transmission rate increases, but the waveform performance in corresponding domains may be degraded
Solution Approach 1:
The patent changes the parameter of tail length by determining it based on energy thresholds in the modulation domain. The tail length is dynamically calculated as a proportion of the total waveform length based on where the energy drops below a certain threshold, allowing optimization of both transmission rate and waveform performance through parameter adjustment rather than fixed truncation.
Solution Approach 2:
The patent applies virtual cutoff rather than complete cutoff of the tailing waveform. By removing only the excessive tailing portion that causes transmission rate reduction while preserving the essential waveform structure, the system achieves partial action that improves transmission rate without completely eliminating the waveform's performance characteristics.
3Productivity
If virtual cutoff is applied to calculate modulation-domain shift interval, then symbol width is reduced and transmission rate is improved, but the tailing waveform is not actually removed which maintains performance
Solution Approach 1:
The patent creates a virtual copy of the waveform for calculation purposes. The virtual cutoff waveform is used to calculate the modulation-domain shift interval, while the original waveform with its tailing is preserved for actual modulation. This copying approach allows the system to benefit from reduced symbol width calculations without actually modifying the waveform structure, thereby avoiding increased complexity.
Data Source
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AI summary
The present invention discloses a modulation method and a modulation apparatus applicable to an OvXDM system, and an OvXDM system. On the one hand, an initial envelope waveform is virtually cut off, and a modulation-domain shift interval is calculated by using a virtual cutoff width of the initial envelope waveform, such that a symbol width obtained after modulation becomes smaller, and a transmission rate is improved; on the other hand, because the initial envelope waveform is virtually cut off but not really cut off, shifting and superimposition are still performed on an initial envelope waveform with tailing, such that the waveform still retains a good performance, such as a relatively narrow width and relatively fast side lobe attenuation, in a corresponding domain. Therefore, in the present invention, the good performance of the waveform is retained in the corresponding domain while the transmission rate is increased.