Orthogonal Waveform Division Multiplexing for High-Density Signaling
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Solution Overview
Problem
Conventional orthogonal multiplex signaling methods are limited by their two-dimensional nature, which restricts information density per symbol due to Euclidean distance and peak power limitations, hindering the efficient transmission of data.
Innovation Solution
The use of orthogonal waveform division multiplexing (OWDM) increases symbol density by selecting a co-set of orthogonal waveforms based on additional data, effectively adding a third dimension to the modulation space, allowing for higher data transmission without additional channels or increased energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If conventional orthogonal multiplex signaling methods are used, then the system is simple to implement, but the information density per symbol is limited due to two-dimensional modulation space constraints
Solution Approach 1:
The patent transitions from two-dimensional modulation (I-Q plane) to three-dimensional modulation by incorporating waveform selection as an additional dimension. The modulation space is extended to include not only amplitude and phase but also waveform family selection, enabling higher information density per symbol period without increasing energy or adding channels
2Productivity
If the number of bits per symbol period is increased using conventional methods, then data transmission capacity improves, but energy consumption and peak power increase
Solution Approach 1:
By adding waveform selection as a third dimension to the modulation space, the system can encode additional bits without increasing the energy of individual symbols. The extra dimension provides more states per symbol period, increasing data capacity while maintaining constant energy per symbol
3Productivity
If more orthogonal waveforms are used to increase data rate, then spectral efficiency improves, but the system becomes more vulnerable to detection and interception
Solution Approach 1:
The orthogonal waveform set is divided into multiple families or co-sets, where each family contains a subset of waveforms. By selecting different families based on additional data bits, the system transmits more information while maintaining the same spectral footprint, making unauthorized detection more difficult
Solution Approach 2:
The system dynamically changes waveform parameters (specifically the family selection) based on the data being transmitted. This parameter variation increases the entropy of the transmitted signal, making it more difficult for unauthorized systems to detect or intercept the communication
Data Source
AI summary
A communications system (100) includes a segmenter (204) for dividing a plurality of bits into a first segment and a second segment and a symbol mapper (208) for generating a plurality of symbols based on the first segment. The system also includes a co-set selector (214) for selecting a plurality of co-set waveforms from a plurality of orthogonal waveforms based on a co-set address defined by the second segment, a number (K) of the plurality of co-set waveforms being less than a number (N) of the plurality of orthogonal waveforms. The system further includes a modulator (210) for modulating the plurality of symbols based on the plurality of co-set waveforms.