Award Abstract # 1738453
SBIR Phase II: Spiral Polynomial Division Multiplexing

NSF Org: TI
Translational Impacts
Recipient: ASTRAPI CORP
Initial Amendment Date: September 21, 2017
Latest Amendment Date: December 11, 2020
Award Number: 1738453
Award Instrument: Standard Grant
Program Manager: Muralidharan Nair
TI
 Translational Impacts
TIP
 Directorate for Technology, Innovation, and Partnerships
Start Date: September 15, 2017
End Date: February 28, 2021 (Estimated)
Total Intended Award Amount: $698,973.00
Total Awarded Amount to Date: $987,173.00
Funds Obligated to Date: FY 2017 = $698,973.00
FY 2018 = $9,830.00

FY 2019 = $138,784.00

FY 2020 = $139,586.00
History of Investigator:
  • Jerrold Prothero (Principal Investigator)
    jprothero@astrapi-corp.com
Recipient Sponsored Research Office: Astrapi Corporation
17217 WATERVIEW PKWY STE 1.202
DALLAS
TX  US  75252-8004
(214)718-0325
Sponsor Congressional District: 04
Primary Place of Performance: Astrapi Corporation
387 Technology Drive,101
College Park
MD  US  20742-5103
Primary Place of Performance
Congressional District:
04
Unique Entity Identifier (UEI): E75XBM5E18P4
Parent UEI: E75XBM5E18P4
NSF Program(s): SBIR Phase II
Primary Program Source: 01001718DB NSF RESEARCH & RELATED ACTIVIT
01001819DB NSF RESEARCH & RELATED ACTIVIT

01001920DB NSF RESEARCH & RELATED ACTIVIT

01002021DB NSF RESEARCH & RELATED ACTIVIT
Program Reference Code(s): 164E, 169E, 4096, 5373, 8034, 8035, 8240, HPCC
Program Element Code(s): 537300
Award Agency Code: 4900
Fund Agency Code: 4900
Assistance Listing Number(s): 47.084

ABSTRACT

The broader impact/commercial potential of this project is that it addresses the bandwidth crisis, the problem of transmitting an exponentially growing amount of data through a fixed amount of increasingly congested spectrum. The bandwidth crisis limits economic growth by constraining communication, and also poses very serious challenges for national defense and disaster response. Making better use of limited spectrum is therefore of high societal and commercial importance. This project will study a new approach, called spiral modulation, for achieving much more spectrally efficient communication than previously thought possible and thereby directly addressing the bandwidth crisis. Commercially, this could facilitate much more rapid data transfer, enhancing existing business applications and enabling new ones. Spiral modulation is applicable to any form of electromagnetic communication, whether wireless or wire-based. It could lead to commercialization across a wide range of communication sectors including but not limited to wireless, mobile internet, unmanned vehicles, automotive, aviation, and Internet of Things. It is a dual use technology with both civilian and defense applications. Ultimately, spiral modulation could become the core technology for the worldwide telecommunications industry.

This Small Business Innovation Research (SBIR) Phase II project applies new mathematics to the problem of encoding information into waveforms for telecommunication. In current digital communication, information is transmitted using symbol waveforms constructed from sinusoids which have constant amplitude over each symbol period. This approach is known to produce a sharp upper bound on the highest spectral efficiency that can be achieved. By instead constructing symbol waveforms from sinusoidal waveforms with continuously-varying amplitude, spiral modulation bypasses the theoretical limitation on spectral efficiency. Building on prior Phase I research, this project will build an end-to-end hardware prototype to establish the implementation path and performance characteristics of spiral modulation. The research will progress in stages from waveform design and spectral efficiency measurement experiments, through end-to-end radio design in software, the hardware prototype development and documentation of best practices. It is anticipated that this research will show significant spectral efficiency advantages over existing signal modulation techniques. Other possible advantages for spiral modulation may also appear, such as greater tolerance for interference and phase distortion.

PROJECT OUTCOMES REPORT

Disclaimer

This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

Project Outcomes

The technology, Spiral Modulation and its derivatives, that was advanced in this project with funding from the NSF enable faster, more robust and more secure radio communications than is possible using existing radio transmission technologies. Spiral Modulation supports more efficient operation of existing radio-based applications, and will enable entirely new classes of applications in civilian and defense terrestrial and space deployments. Spiral Modulation permits faster data throughput, increased resistance to interference, and significantly lower power operation and it introduces an entirely new way of designing radio transmission signals. Further benefits arise from the derivative technologies. 

This project pioneered the use of a continuously non-stationary spectrum for telecommunications. By exploiting signal power variations to bypass an implicit assumption in traditional channel capacity theory that the spectrum is at least approximately stationary (constant power in each frequency), it is possible to drive spectral efficiency much higher than was previously thought possible. Astrapi started with new mathematics, developed MATLAB software simulations, and produced two generations of Software-Defined Radio (SDR) prototype implementations, the current utilizing a state-of-the-art Xilinx RF System-on-a-Chip platform. We showed, with external validation, a factor-of-two (2-4 dB) signal power win over traditional signal modulation with other parameters matched. While our Spiral Modulation technology is still pre-product, NSF funding helped us develop an open path to address very large markets that include defense, satellite, terrestrial wireless, and Internet of Things (IoT) networks which are channel capacity and signal power constrained. Applications are centered around lower signal power, higher data throughput, lower occupied bandwidth, improved Size, Weight, Power and Cost (SWaP-C), interference mitigation, Low Probability of Intercept (LPI), anti-jamming, and Low Probability of Detection (LPD). Derivative technologies arising in part from this project address advanced non-stationary geo-location tracking in harsh, congested environments.

We have initial validation of our licensing model that facilitates parallel commercial and defense deployment through existing Original Equipment Manufacturers (OEMs). Our initial license directly led to the formation of a strategic alliance with Space Strategies Consulting Ltd. (SSCL) for Canadian market development.

In the course of our R&D, we developed new patented technologies for designing the symbol waveforms used to transmit bits. Basing symbol waveforms on polynomials, we used Monte Carlo and Machine Learning techniques to produce Polynomial Symbol Waveform (PSW) alphabets that combined high noise resistance with low bandwidth (frequency range) usage.

Our primary R&D described above led to two new derivative technologies, both with unique and important capabilities. These are the Astrapi Software Spectrum Analyzer (SSA) and Symbol Waveform Hopping (SWH).

Typically, a Fourier transform is used to analyze Power Spectral Density (PSD), that is, how power is distributed over the frequencies of the spectrum. However, the Fourier transform assumes the spectrum is at least approximately stationary and returns incorrect results if it is not. A Hardware Swept-Tuned Spectrum Analyzer (HSTSA) can be used to measure the PSD of a non-stationary spectrum correctly, and was initially used by Astrapi as part of PSW alphabet design, but they are expensive, slow and cumbersome for this purpose.

Astrapi therefore developed, for its own internal use, a patent-pending and externally validated SSA which for the first time enables accurate PSD measurement of a non-stationary spectrum (unlike the Fourier transform) in software (unlike an HSTSA). External applications for the SSA are now being validated and include geo-location in the field for uses such as drone and adversary tracking.

The huge symbol waveform design space made available by PSW alphabet design has a second benefit, besides improving noise resistance. It enables Symbol Waveform Hopping (SWH), a new, advanced form of Low Probability of Intercept (LPI) signal security. SWH can be thought of as analogous to Frequency Hopping (FH), but in the time domain rather than the frequency domain. SWH is unique in that it is both theoretically secure (unlike FH); and has no latency, data throughput, or power overhead (unlike encryption). Early validation of this advanced technology was achieved through the U.S. Air Force Catalyst Cyber Space program sponsored by the Air Force Research Lab/Space Vehicle Directorate.

Astrapi?s NSF-funded research has opened up new capabilities at the foundations of telecommunications and beyond. The impact of this work is already apparent, and will continue to grow for years to come. In spite of the disruptive impact of COVID-19 on our prospective licensees, investors, teaming partners, employees, and, of course, NSF program management and staff, 2020 was a key infection year for the advancement of Spiral Modulation. 2021 is shaping up to be a key year in transitioning the technology.

 


Last Modified: 01/04/2021
Modified by: Jerrold D Prothero

Please report errors in award information by writing to: awardsearch@nsf.gov.

Print this page

Back to Top of page