Christopher Anderson

• Doctor of Philosophy
• Professor (Associate) at United States Naval Academy

The capabilities of the millimeter wave (mmWave) spectrum to fulfill the ultra high data rate demands of V2X (Vehicle-to-Everything) communications necessitates the need for accurate channel modeling to facilitate the efficient development of next-generation network and device design strategies. Ergo, this work describes the design of a novel fully...

The 6 GHz spectrum is emerging as one of the important sub-7 GHz bands for spectrum sharing. A critical issue for 6 GHz spectrum sharing is the potential for interference to existing users such as fixed microwave links (FMLs). This paper addresses this critical issue by outlining a methodology for lab-based experimentation for characterizing receiv...

The wireless spectrum is a natural resource upon which we all depend in more ways than we realize. While our personal and professional lives thrive on mobile broadband, a plethora of other applications, such as weather forecasting, climate science, astronomy, space exploration, and civil/military navigation also critically depend on the radio spect...

This paper details the design of an autonomous alignment and tracking platform to mechanically steer directional horn antennas in a sliding correlator channel sounder setup for 28 GHz V2X propagation modeling. A pan-and-tilt subsystem facilitates uninhibited rotational mobility along the yaw and pitch axes, driven by open-loop servo units and orche...

On-demand deployment of mobile communication infrastructure has emerged as a promising solution for extending cellular coverage in rural areas. However, most current research focuses on theoretically optimizing the trajectory of unmanned aerial vehicle (UAV) relays/base stations in simplified geographic scenarios. These network-side attempts have f...

This paper outlines the components of a digital spectrum twin (DST) and potential application maps that can inform automated or enhanced spectrum management decisions. The DST is fundamentally a map and image database, with environmental, measurement, and prediction maps that allow parallel intelligence operations to generate useful information usi...

The wireless spectrum is a natural resource upon which we all depend in more ways than we realize. While our personal and professional lives thrive on mobile broadband, a plethora of other applications, such as weather forecasting, climate science, astronomy, space exploration, and civil/military navigation also critically depend on the radio spect...

This letter investigates propagation at 7 and 13 GHz in urban locations motivated by coexistence studies in the recently opened 6 GHz band (5925-7125 MHz) and in the similar 13 GHz band (12700-13250 MHz). Path loss measurements were collected in four urban areas in both line-of-sight (LOS) and non-LOS (NLOS) conditions. We derive floating-intercept...

Over the past decade, spectrum sharing has evolved into viable commercial systems poised to meet the ever-increasing spectrum demand from service providers and end users. The key to the success of these systems is accurate and reliable propagation models that will simultaneously maximize the number of users able to access the spectrum and minimize...

As CubeSats have become hugely popular in the recent years, the demand on their capability has also increased. As the missions and functionalities become more complex, coupled with the popular VHF and UHF bands becoming less accessible, CubeSats have been getting pushed into using higher frequency bands. For more capable CubeSats such as NASA and m...

Over the past decade, spectrum sharing has evolved into viable commercial systems poised to meet the ever-increasing spectrum demand from service providers and end users. The key to the success of these systems is accurate and reliable propagation models that will simultaneously maximize the number of users able to access the spectrum and minimize...

Broadband access is key to ensuring robust economic development and improving quality of life. Unfortunately, the communication infrastructure deployed in rural areas throughout the world lags behind its urban counterparts due to low population density and economics. This article examines the motivations and challenges of providing broadband access...

Classical propagation models currently utilized in spectrum management have a limited incorporation of foliage and clutter effects that result in inefficient spectrum utilization in modern spectrum-sharing scenarios. Recent propagation modeling efforts have increasingly utilized machine-learning approaches that demonstrate significantly improved pe...

In this paper, we discuss the design of a sliding-correlator channel sounder for 28 GHz propagation modeling on the NSF POWDER testbed in Salt Lake City, UT. Beam-alignment is mechanically achieved via a fully autonomous robotic antenna tracking platform, designed using commercial off-the-shelf components. Equipped with an Apache Zookeeper/Kafka ma...

The goal of this article is to investigate the propagation behavior of 28-GHz millimeter wave in coniferous forests and model its basic transmission loss. Field measurements were conducted with a custom-designed sliding correlator sounder. Relevant foliage regions were extracted from high-resolution LiDAR data and satellite images. Our results show...

The goal of this article is to investigate the propagation behavior of 28-GHz millimeter wave in coniferous forests and model its basic transmission loss. Field measurements were conducted with a custom-designed sliding correlator sounder. Relevant foliage regions were extracted from high-resolution LiDAR data and satellite images. Our results show...

A rapidly deployable and cost-effective railroad crossing early warning system integrated with the railway system is attractive due to its protection of the unmanned grade crossings, which requires a warning system with long-distance communication link. In this paper, we investigate the problem of suitable antenna selection for such a railway warni...

In this demonstration proposal, we present a prototype of a rapidly deployable and cost-effective railroad crossing early warning system integrated with the railway system. Specifically, the proposed demonstration deal with the safety applications based on dedicated short range communications (DSRC) protocol and devices using our different antennas...

This report describes a set of best practices for the preparation and verification of radio propagation measurement systems. We discuss advantages and disadvantages of various channel sounders, the common components used in these systems, and measurement of these components. We then move to system verification measurements both on the benchtop and...

Despite the rapid development of wireless technology, there has been little application of the technology to improve railroad crossing safety. We present vehicle-to-railroad channel characterization and dedicated short range communications (DSRC) performance results at railroad crossings in rural and suburban environments. Our results show that an...

In the United States, government and commercial entities have begun sharing the 3550–3650 MHz military Radar band. The key to ensuring successful sharing is robust interference prediction based on accurate and reliable propagation models. This paper presents the results of a comprehensive propagation measurement and modeling campaign for the 3.5 GH...

Radio tomographic imaging (RTI) has recently been proposed for tracking object location via radio waves without requiring the objects to transmit or receive radio signals. The position is extracted by inferring which voxels are obstructing a subset of radio links in a dense wireless sensor network. This paper proposes a variety of modeling and algo...

This paper presents the development of an in situ measurement system known as the Debris Resistive Acoustic Grid Orbital Navy/NASA Sensor (DRAGONS). The DRAGONS system is designed to detect impacts caused by particles ranging from 50 micrometers to 1 mm at both low-earth and geostationary orbits. DRAGONS utilizes a combination of low-cost sensor te...

Background Spontaneous magnetic alignment (SMA), in which animals position their body axis in fixed alignments relative to magnetic field lines, has been shown in several classes of vertebrates and invertebrates. Although these responses appear to be widespread, the functional significance and sensory mechanism(s) underlying SMA remain unclear. An...

In this paper, we propose an approach for mitigating deterministic and partially deterministic jamming signals from the received signal space, thus yielding recoverable signal vectors at a target receiver. Aimed at friendly or self-jamming environments, where enemy communication jamming is paramount. The proposed approach employs a concept called s...

This paper presents the development of an in situ measurement system known as the Debris Resistive Acoustic Grid Orbital Navy/NASA Sensor (DRAGONS). The DRAGONS system is designed to detect impacts caused by particles ranging from 50 μm to 1 mm at both low-earth and geostationary orbits. DRAGONS utilizes a combination of low-cost sensor technologie...

This paper describes studies leading to the development of an acoustic instrument for measuring properties of micrometeoroids and other dust particles in space. The instrument uses a pair of easily penetrated membranes separated by a known distance. Sensors located on these films detect the transient acoustic signals produced by particle impacts. T...

Orbital debris poses a constant threat to satellites. Some larger debris can be tracked and avoided, but smaller objects cannot be tracked. In addition, there exists a data gap in orbital debris dispersion models for particles less than 5 mm in diameter. The Debris Resistive/Acoustic Grid Orbital Navy Sensor (DRAGONS) fills this critical gap in deb...

This paper presents a pioneering study based on a series of experiments on the operation of commercial Time-Division Long-Term Evolution (TD-LTE) systems in the presence of pulsed interfering signals in the 3550-3650 MHz band. TD-LTE operations were carried out in channels overlapping and adjacent to the high power SPN-43 radar with various frequen...

This paper presents a pioneering study based on a series of experiments on the operation of commercial Time-Division Long-Term Evolution (TD-LTE) systems in the presence of pulsed interfering signals in the 3550-3650 MHz band. TD-LTE operations were carried out in channels overlapping and adjacent to the high power SPN-43 radar with various frequen...

Six broadband measurements were made of the transmission at 3–4 GHz between two horn antennas 30 cm above the ground through 80 cm tall grass. Water was sprayed over the tall grass, and the variation in transmission was captured as the water evaporated. The results show an increase in transmission through the wet grass of 6.5 dB at an 8 m distance....

Software-defined radio is a rapidly developing field that is driving the development of and innovation in communications technology, and promises to significantly impact all communications sectors. Entities developing these SDR systems require a trained workforce that has been prepared with the mindset, knowledge, skills, and tools required to addr...

The 13 papers in this special issue focus on non-cooperative localization networks.

Radio tomographic imaging (RTI) has recently been proposed for tracking object location via radio waves without requiring the objects to transmit or receive radio signals. The position is extracted by inferring which voxels are obstructing a subset of radio links in a dense wireless sensor network. This paper proposes a variety of modeling and algo...

Impulse ultrawideband (UWB) communication promises a number of benefits for use in wireless sensor networks, particularly in forest environments, where it has the potential to provide robust operation, along with the ability to combine communications with precision position location. In this paper, we present measurement results and empirical model...

Magnetoreception has been demonstrated in all five vertebrate classes. In rodents, nest building experiments have shown the use of magnetic cues by two families of molerats, Siberian hamsters and C57BL/6 mice. However, assays widely used to study rodent spatial cognition (e.g. water maze, radial arm maze) have failed to provide evidence for the use...

Water maze release device. A) Mouse was transported from the holding shelf to the testing arena inside the opaque release device. Disks of paper towel attached with a ring cut from a self-adhesive label covered openings in both the top and bottom of the chamber. B) The release device was then slid slowly down onto a vertical Plexiglas rod extending...

Number of littermates in the same testing group may affect the consistency of orientation. Although mice from littermate groups of both (A) 1-2 and (B) 3+ exhibited significant orientation in the trained magnetic direction (p < 0.01, Rayleigh test), mice in littermate groups of 1-2 to exhibited less scatter (p < 0.05, Watson U2 test). Each mouse wa...

Responses included in Figure 2†. (DOCX)

Holding shelf. Mice were held in individual cages on non-magnetic shelves outside the testing room between training and testing trials. After returning from the water maze, mice were placed under a 75 W heat lamp that illuminated half the cage until their fur was dry. They were then returned to the holding shelves. Grounded shielding, consisting of...

Evidence for olfactory following. Example of data obtained in some tests before a cleaning protocol was introduced between testing trials to disperse directional olfactory cues left by the previous mouse. Distributions of bearings in A & B show the deviations between the topographic bearings of pairs of mice tested sequentially that were either lit...

Responses of south trained mice in Figure S3. (DOCX)

Responses included in Figure 3††. (DOCX)

A spectral domain method is presented to calculate the potential of a vertical dipole in a multilayered medium as a model of long-range radio propagation. The spectral domain Green's function (SDGF) for structures with up to hundreds of thousands of layers is calculated using an efficient matrix formulation, thus enabling simulation of continuously...

This paper demonstrates methods to select and apply regularization to the linear least-squares model formulation of the radio tomographic imaging (RTI) problem. Typically, the RTI inverse problem of image reconstruction is ill-conditioned due to the extremely small singular values of the weight matrix which relates the link signal strengths to the...

It is now well understood that by exploiting the available additional spatial dimensions, multiple-input multiple-output (MIMO) communication systems provide capacity gains, compared to a single-input single-output systems without increasing the overall transmit power or requiring additional bandwidth. However, these large capacity gains are feasib...

Using simulated data with varying Rician K-factor, averaging block length (N), and sample size (P), this letter proposes and validates two new moment-based, unbiased estimators for block-averaged Rician data and presents a model for their standard errors. One estimator, K̑1,2, has standard error that varies linearly with K and requires iterative ca...

This paper proposes and demonstrates the novel application of a secure wireless sensor network for roadside surveillance and vehicular detection using radio tomographic imaging. Network architecture is based on the well-established Zigbee standard and medium access is provided through a time division multiple access scheme. Wireless security vulner...

The Debris Resistive Acoustic Grid Orbital Navy Sensor (DRAGONS) is a spacecraft-mounted instrument designed to detect microscopic sized particles in polar and sunsynchronous orbits at 800-900 km which are currently undetectable by ground-based systems. Current orbital debris detection systems are dependent on ground based radars, which only have t...

Radio tomographic imaging (RTI) has recently been proposed for tracking object location via radio waves without requiring the objects to transmit or receive radio signals. The position is extracted by inferring which voxels are obstructing a subset of radio links in a dense wireless sensor network. This paper proposes a refined model for signal att...

In this paper, we derive the Cramer-Rao Lower Bound (CRLB) within the Bayesian setup for time-varying multiple-input/multiple-output channel estimation. We consider the transmitting signal to be composed of linearly precoded information symbols and training symbols such that they share the same channel resource. This framework consisting of linearl...

With an emphasis on the role of wireless communications, this paper defines the cyber domain from a technical point of view. It divides the domain into three functional layers: the core, wireless and cross-domain interface. This paper highlights the role and security vulnerabilities of the wireless layer and asserts the need for increasing research...

Due to their small size, low loss, and compatibility with integrated circuits, microelectromechanical systems (MEMS) have been the focus of recent efforts at developing frequency reconfigurable patch antennas able to operate at a number of different user-selected frequencies. Although reactive loading with MEMS variable capacitors is a well-documen...

A software-defined radio (SDR) for ultrawideband (UWB) communication systems places several stringent requirements on the analog-to-digital converter (ADC). One alternative to using a single ADC is to sample the received signal with an array of lower speed ADCs that were driven by interleaved sampling clocks; however, mismatches among the ADCs will...

This paper proposes a practical alternative to the traditional link budget approach for impulse-based UWB systems (I-UWB), which is based on the Friis formula. The proposed link budget approach overcomes the narrowband limitations of the traditional link budget by proposing the use of an antenna-pulse coupling gain. This gain is specific for an ant...

Impulse ultra wideband (UWB) communications promises a number of potential benefits for use in wireless sensor networks-particularly in forest environments where it can provide robust operation along with the ability to combine communications with precision position location. Additionally, MIMO communications for UWB provides the ability to take ad...

Radio technology has advanced tremendously over the past century with increased capacities and addressing a disparate range of applications. However, from an external perspective, the design philosophies behind radio architectures and wireless standards remain rooted in the methodologies of the 1930's. In this paper, we propose that this conservati...

Over the past decade, research and development in wireless sensor networks has investigated novel and exciting applications for a number of different scenarios. Impulse ultra wideband (UWB) communications promises a number of benefits for use in wireless sensor networks-particularly in forest environments where it can provide robust operation along...

In an underground mine, wireless systems based on ultra wideband (UWB) signals have the potential to improve the response time to mine emergencies by providing fast, reliable communications as well as precision position location. Much of the UWB research to date has focused on the in-building and (to a lesser degree) outdoor propagation environment...

In an underground mine, wireless systems based on ultra wideband (UWB) signals have the potential to improve the response time to mine emergencies by providing fast, reliable communications as well as precision position location. Much of the UWB research to date has focused on the in-building and (to a lesser degree) outdoor propagation environment...

A software defined radio for ultra wideband (UWB) communication systems places several stringent requirements on the analog-to-digital converter (ADC). In particular, the ADC must have sufficiently high sampling frequency-typically on the order of several gigasamples per second-to accurately reconstruct the received UWB pulse. An alternative approa...

Near-ground radio-wave propagation is of interest for emerging military applications such as battlefield sensor networks and for wireless communication between dismounted soldiers. Narrowband and wideband channel measurement results at 300 and 1900 MHz are presented for near-ground propagation, characterising the effect of antenna heights, radiatio...

Vital-signs monitoring devices continue to utilize invasive sensing methodologies, ranging from skin surface contact techniques such as the use of electrodes for measuring car-diac signals (ECG test), to more intrusive techniques such as the utilization of a facial mask for measuring gas exchange during respiration. In this paper, we present a wire...

Previous work has shown that UWB systems can be used for remote vital-signs monitoring, with the major applications of these systems being in health monitoring and rescue scenarios. In this paper, we demonstrate the use of impulse-based UWB signals in the robust detection of chest-cavity motion and the accurate estimation of respiration and heart-b...

Software defined radios have the potential of changing the fundamental usage model of wireless communications devices, but the capabilities of these transceivers are often limited by the speed of the underlying processors and FPGAs. This paper presents a testbed for the design of an impulse-based ultra wideband communication system. The transceiver...

A global optimization technique is applied to solve the optimal transmitter placement problem for indoor wireless systems. An efficient pattern search algorithm - DIviding RECTangles (DIRECT) of Jones et al.- has been connected to a parallel three-dimensional radio propagation ray tracing modeler running on a 200-node Beowulf cluster of Linux works...

This paper contains measured data and empirical models for 2.5 and 60 GHz in-building propagation path loss and multipath delay spread. Path loss measurements were recorded using a broadband sliding correlator channel sounder which recorded over 39000 power delay profiles (PDPs) in 22 separate locations in a modern office building. Transmitters and...

First Page of the Article

Wideband measurements were performed using a direct-sequence spread-spectrum measurement system in the air-to-ground radio environment to characterize propagation between an airborne transmitter and a ground-based receiving antenna array at a center frequency of 2.05 GHz. The transmitter was flown along constant-radius arcs at low altitudes around...

This paper is a step toward defining the characteristics of a suitable antenna to exploit the inherent advantages in pulsed communication systems, specifically that of ultra-wideband. In this respect, several traditional broadband antenna architectures are evaluated with an emphasis given towards a time-domain perspective. In addition, a good UWB a...

In today's world, the ubiquitous nature of wireless personal systems has lead to an increasing concern regarding the safety and reliability of the electromagnetic environment (EME) in hospitals and clinics. Additionally, modern hospitals are becoming populated with wireless medical applications. Research conducted on the EME so far has only conside...

The Vivaldi antenna is an extremely broadband configuration that can be readily designed with modern CAD tools and fabricated with standard high-frequency substrate materials.

In this paper, radiation from microwave ovens is measured using PRISM, a custom-built device designed to measure transmissions in the ISM band. The measured signals, treated as a rising noise floor, are then applied to a semianalytic simulation to determine the probability of frame error rate (FER) per channel for six Bluetooth packet types [1].

In this paper, a global optimization technique is applied to solve the optimal transmitter placement problem for indoor wireless systems. An e#cient pattern search algorithm---DIRECT (DIviding RECTangles) of Jones, Perttunen, and Stuckman (1993)---has been connected to a parallel 3D radio propagation ray tracing modeler running on a 200-node Beowul...

This paper explores the application of a global optimization technique to solve the optimal transmitter placement problem in wireless system design. An e#cient pattern search algorithm---DIRECT (DIviding RECTangles) of Jones, Perttunen, and Stuckman (1993)---has been connected to a parallel 3D radio propagation ray tracing modeler running on a 200-...

This paper presents the performance of space-time block coding based transmit diversity (STTD) in WCDMA on correlated fading channels and on unbalanced transmitted power. Then, based on the performance, transmitter location optimization in indoor environments is considered. Results indicate that the effective diversity order is retained even when h...

This paper contains measured data for 2.5 and 60 GHz in-building partition loss. Path loss measurements were recorded using a broadband sliding correlator channel sounder which recorded over 39000 power delay profiles (PDP) in 22 separate locations in a modern office building. Transmitters and receivers were separated by distances ranging from 3.5...

In this paper, radiation from microwave ovens is measured using PRISM, a custom-built device designed to measure transmissions in the ISM band. The measured signals, treated as a rising noise floor, are then applied to a semi-analytic simulation to determine the probability of frame error rate (FER) per channel for six Bluetooth packet types.

With the integration of the Internet and multimedia applications in next generation wireless communications, the demand for reliable high data rate services is rapidly growing. Traditional wireless communications systems use a single input single output (SISO) channel, meaning one antenna at each side of the link. Information theory research has sh...

A Software Defined Radio for Ultra Wideband (UWB) communication systems places several stringent requirements on the Analog to Digital Converter (ADC). The ADC must have a sufficiently fast sampling frequency and SNR to accurately reconstruct the received UWB pulse. Such an ADC can be prohibitively expensive, as well as challenging to interface wit...

Spectrum sensing cognitive radios are an emerging technol-ogy that promises greater efficiency in utilizing the available wireless spectrum. In particular, spectrum-sensing cognitive radios provide the ability to search for and utilize an un-occupied portion of the wireless spectrum during periods of time when the incumbent user is inactive. A key...