IMPROVING DIGITAL HIGH FREQUENCY (HF) COMMUNICATIONS WITH MULTI-DIMENSIONAL CONSTANT ENERGY MODULATION IMPLEMENTATION
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Authors
Waymouth, Adam J.
Subjects
multiple-input multiple-output
MIMO
orthogonal frequency division multiplexing
OFDM
modulation
high frequency
HF
multi-dimensional
digital communication
GNU
GNU Radio Companion
GRC
Software Defined Radio
SDR
X310
fading
FPGA
field programmable gate array
QPSK
quadrature phase shift keying
QAM
quadrature amplitude modulation
STBC
space time block code
BER
bit error rate
SATCOM
satellite communication
OTH
over-the-horizon
MIMO
orthogonal frequency division multiplexing
OFDM
modulation
high frequency
HF
multi-dimensional
digital communication
GNU
GNU Radio Companion
GRC
Software Defined Radio
SDR
X310
fading
FPGA
field programmable gate array
QPSK
quadrature phase shift keying
QAM
quadrature amplitude modulation
STBC
space time block code
BER
bit error rate
SATCOM
satellite communication
OTH
over-the-horizon
Advisors
Romero, Ric
Ha, Tri T.
Date of Issue
2020-09
Date
September 2020
Publisher
Monterey, California. Naval Postgraduate School
Language
Abstract
Improved high frequency (HF) digital communication is desired in commercial and military applications,
especially at sea where the primary digital communications is satellite communications (SATCOM). HF
over-the-horizon (OTH) relays are often the alternative communication path when SATCOM is too costly or not
available. Our work suggests using multiple-input multiple-output (MIMO), orthogonal frequency division
multiplexing (OFDM), and various modulations in HF OTH communications to reduce the bit error rate (BER),
improve data throughput in the allocated bandwidth, and potentially provide physical layer security through
obfuscation. We implement MIMO, OFDM, and multi-dimensional constant energy modulation (CEM) by
utilizing GNU Radio Companion (GRC) to program two NI Ettus X310 Software Defined Radios (SDR) in a 2x2
MIMO configuration. This is the first time CEM has been transmitted and received. Modulation and demodulation
are successful for various file types. The 4D-16 CEM constellation and its BER are compared to that of quadrature
phase shift keying (QPSK) and 16-quadrature amplitude modulation (QAM). Explanations of how CEM, OFDM
subcarriers, and space time block codes (STBC) can provide frequency agility, throughput manipulation, and
physical layer security are provided. Selected CEM constellations are presented.
Type
Video
Description
Approved for public release. Distribution is unlimited.
Series/Report No
Department
Electrical and Computer Engineering (ECE)
Organization
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.