Spiral Modulation and Symbol Waveform Hopping
Astrapi® applies new engineering and mathematics to utilizing and measuring continuously nonstationary spectrum, in which the power in each frequency is continuously changing. Astrapi’s technology development has been funded by private investment, the Department of Defense, and the National Science Foundation.
In telecommunications, our approach led to Astrapi’s patented ‘Spiral Modulation and Symbol Waveform Hopping technologies.
How Spiral Modulation Works
Spiral modulation increases spectral efficiency compared to traditional signal modulation techniques. This allows, for a given amount of channel noise and available bandwidth (frequency range), for signal power to be reduced and/or data throughput to be increased. Reduced signal power can be used to reduce battery requirements, and for signal protection applications to disguise the existence of the signal.
Symbol Waveform Hopping
Astrapi’s patented Symbol Waveform Hopping technology is a new way to protect a signal at the physical layer. It combines three characteristics that cannot be achieved otherwise:
- It is theoretically secure, unlike frequency hopping. Symbol Waveform Hopping is based on resolution against the noise floor and is protected by very fundamental thermodynamic and channel capacity laws.
- It has no latency or power overhead, unlike traditional bit-level encryption.
- It is inherently secure against quantum computers, because the Symbol Waveform Hopping challenge to the adversary is not computational complexity, it is resolution against the noise floor. No amount of computation can improve resolution.
Symbol Waveform Hopping is based on using the very large bandlimited symbol waveform design space created by Spiral Modulation to provide both a recognizable small set of possible symbol waveforms to the intended receiver, and a much larger set of possibilities to an adversary who does not know which symbol waveforms are in use in a given time period. In communication theory terms, the adversary has to attempt to receive a signal with an effective data rate much higher than the channel capacity. This is inherently impossible.