Mode Hopping Spread Spectrum Modulation for Antenna Arrays
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Solution Overview
Problem
Conventional frequency hopping spread spectrum methods face limitations in achieving both spectral efficiency and security, as they rely on changing carrier frequencies, which can lead to detectable power spectral density and interference.
Innovation Solution
The mode hopping spread spectrum technique uses pseudo-random number sequences to switch between different propagation modes of the same frequency, adding an additional dimension to conventional modulation schemes, allowing for secure and efficient data transmission by rotating the wave front phase across multiple quantum states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequency hopping spread spectrum is used to improve security and spectral efficiency, then privacy and resistance to interference are enhanced, but the power spectral density becomes detectable and interference increases
Solution Approach 1:
The patent transitions from frequency-domain hopping to mode-domain hopping. Instead of changing carrier frequencies across many available frequencies, the system hops between different propagation modes (wavefront structures) at a consistent frequency. This dimensional shift to mode space allows the signal to spread across multiple quantum states while maintaining a narrow frequency bandwidth, thereby reducing power spectral density without sacrificing security.
Solution Approach 2:
The patent changes the modulation parameter from frequency to mode. By using mode hopping instead of frequency hopping, the system varies the wavefront phase across multiple quantum states while maintaining a consistent carrier frequency. This parameter change enables the signal to occupy a wider effective bandwidth in mode space while appearing narrow in frequency space, resolving the contradiction between security and power spectral density.
2Productivity
If frequency hopping is used to spread a narrow bandwidth signal over a wider bandwidth, then spectral efficiency is improved, but the overall bandwidth requirement increases significantly
Solution Approach 1:
The patent exploits the mode domain as an additional dimension for signal spreading. By hopping between different propagation modes (wavefront structures) at a consistent frequency, the system achieves spectral efficiency without requiring a wide frequency bandwidth. The mode hopping provides the necessary bandwidth expansion in the mode domain while maintaining a narrow frequency footprint.
Solution Approach 2:
The patent segments the signal transmission into different propagation modes, each representing a distinct wavefront structure. By dividing the signal across multiple modes rather than using a single frequency, the system achieves efficient use of available spectral resources while maintaining a compact frequency bandwidth requirement.
3Loss of energy
If mode hopping spread spectrum is used to maintain consistent frequency, then power spectral density is reduced, but the complexity of mode switching increases
Solution Approach 1:
The patent replaces complex frequency switching mechanisms with mode switching based on wavefront phase rotation. Instead of mechanically changing carrier frequencies across a wide bandwidth, the system rotates the wavefront phase across multiple quantum states at a consistent frequency. This substitution simplifies the switching mechanism while achieving the desired power spectral density reduction.
Solution Approach 2:
The patent changes the switching parameter from frequency to mode. By varying the wavefront phase (mode) rather than the carrier frequency, the system achieves power spectral density reduction with simpler switching complexity. The mode switching operates at a consistent frequency, eliminating the need for complex frequency tuning mechanisms.
Data Source
AI summary
A method and apparatus for data modulation in an antenna array include: storing input data comprising of a plurality of data bits, in a buffer; generating a pseudo random number; computing a transmission mode from the pseudo random number; based on the computed transmission mode and the number of antenna elements in the antenna array, computing a particular phase offset for each antenna element; sequentially providing the stored input data, one bit at a time, to each antenna element; and transmitting the input data from each antenna element according to the computed particular phase offset for said each antenna element.