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Pankil Butala

2nd

Previous positions

  • Staff Embedded Softwate Engineer at Qualcomm
  • Senior Embedded Software Engineer at Qualcomm

Education

Boston University, Ph.D., Electrical Engineering

415

Background

Summary

Experienced Embedded Software Engineer with a demonstrated history of working in the wireless industry.

Experience

  • Software Engineer

    Apple

    September 2019 – Present(1 month)San Diego, California

  • Staff Embedded Softwate Engineer

    Qualcomm

    November 2018 – September 2019(10 months)San Diego, California

    • Innovate, design and implement embedded drivers for cutting edge RF and modem hardware to support 4G and 5G wireless technologies. • Responsible to design and implement RF drivers and interfaces to support NR5G MMW – – DL gain control to support AGC – DL frequency compensation – UE DL beam switches to support mobility – Automatic frequency control (AFC) to support frequency tracking loops – Jammer detection and mitigation – Maximum permissible exposure (MPE) for user detection and mitigation via cap on UL power • Prior responsibilities include design and implement RF drivers and interfaces to support 4G LTE – – UL carrier aggregation – UL power limiting and control • Work with factory team to provide interfaces to support calibration for above mentioned algorithms. • Work with protocol, firmware and test teams to drive design, implement interfaces and algorithms and ensure conformance to 3GPP standards. • Work with customer engineering team to support customer issues. • Mentor, collaborate and lead a team to participate in product development lifecycle from inception and design to bring-up, optimization, verification and commercialization. • Responsible to set up team wide periodical training sessions.

  • Senior Embedded Software Engineer

    Qualcomm

    June 2015 – November 2018(3 years 5 months)Greater San Diego Area

  • Research Assistant

    Multimedia Communication Lab and Smart Lighting Engineering Research Center

    September 2011 – June 2015(3 years 9 months)Boston University, Boston, MA

    • Designing Xilinx FPGA based optical wireless 4×4 MIMO system with an imaging receiver and implementing OFDM variant as modulation at PHY. • Generating optical MIMO system specifications to develop prototypes in collaboration with partners. • Developed a wireless, networked color sensor platform (CuSP) to deploy in smart spaces. • Designed an iOS app and wireless, networked inertial sensors (FAM) for monitoring, detection and real time classification of functional activity.

  • Software Engineer

    Advanced Analytical Technologies, Inc

    March 2009 – July 2010(1 year 4 months)Ames, IA

    • Developed GUI data analysis and controller software in C# for analytical laboratory instruments. • Implemented real time control, digital signal processing, pattern search and match algorithms.

  • Software Engineer

    Enova Systems, Inc. / Hyundai Enova ITC

    August 2007 – March 2009(1 year 7 months)Torrance, CA

    • Developed embedded code in C/C++ for hybrid vehicle motor drive control modules. • Developed an in house UI tool to obtain real time system diagnostic data. • Company representative for on-site integration in UK and Hawaii.

  • Engineering Intern

    Lilavati Hospital and Research Center

    June 2005 – December 2005(6 months)Mumbai, India

    • Serviced and maintained imaging, analytical and diagnostic machines.

Education

  • Boston University

    Ph.D., Electrical Engineering

    2010 – 2015

    • Ph.D. Thesis: Optical MIMO communication systems under illumination constraints. Advisor: Prof. Thomas Little. • Developing low complexity spectrally efficient MIMO OFDM signaling schemes. • Investigating optical MIMO wireless signaling techniques.

    Activities and Societies

    • President of Student leadership council, Smart lighting ERC. (Since 2014) • Chair of Engineering students’ workshop, Boston University. (2014) • Won perfect pitch competition, Smart lighting industry-academia event. (2014) • Captain of soccer team, Student association of graduate engineers. (2012-2013) • Awarded prestigious dean’s fellowship. (2010-2011)

  • University of California, Los Angeles

    Master of Science (M.S.), Biomedical/Medical Engineering

    2006 – 2007

    • Designed multi-tap FIR/IIR digital filters. • Developed java based GUI to parse DICOM images. • Subjects studied include advanced digital signal processing, statistics and analog circuit design.

  • University of Mumbai

    Bachelor’s degree, Bioengineering and Biomedical Engineering

    2002 – 2006

    • Senior project: Travelling photometer. Developed prototype for analytical laboratory instrument in R&D phase at Transasia Bio-Medicals Ltd., Mumbai. • Subjects studied include microprocessors, computer programming, advanced digital signal and image processing, control systems, analog and digital electronic circuits.

  • Utpal Sanghvi School

Languages

  • English

    Full professional proficiency

  • Hindi

    Professional working proficiency

  • Marathi

    Professional working proficiency

  • Gujarati

    Native or bilingual proficiency

Publications

  • Performance of Color Shift Keying under non-linear system model and illumination constraints

    IEEE Globecom Workshop on Optical Wireless Communications (OWC)

    December 2015

    The IEEE 802.15.7 standard defines specifications for short-range optical wireless communication (OWC) using visible light. The standard specifies color shift keying (CSK) as the preferred modulation scheme for indoor OWC while simultaneously providing illumination. In light of illumination requirements, human eye’s optical perception introduces unique non-linearities in the CSK signaling chain. It is shown that these non-linearities introduce performance penalties of more than 15 dB, 10 dB, and 5 dB for M = 4, 8, and 16 CSK respectively. A new metric called luminous-signal-to-noise ratio (LSNR) is also introduced to fairly compare performance of any two OWC signaling schemes operating at a user defined illumination intensity level and is used to compare performance of M-ary CSK implemented with different colored sources. Within the same context, and at a target bit error rate of ≤ 10−3, simulation results indicate that clipping negative receiver output signal does not have an impact on M-ary CSK performance.

    Authors (3):
    • Pankil Butala,
    • Hany Elgala,
    • Thomas DC Little
  • Trace-Orthogonal PPM-Space Time Block Coding Under Rate Constraints for Visible Light Communication

    Journal of Lightwave Technology

    January 2015

    Visible light communications (VLC) represents a new frontier of communications allowing high data-rate Internet access, specially in indoor environments, where the use of light emitting diodes (LEDs) is growing as a viable alternative to traditional illumination. As a result, LED output intensity can be varied faster than human eye can perceive, thus guaranteeing simultaneous wireless communications and illumination. One of the key challenges is the limited modulation bandwidth of sources that is typically around several MHz. The use of multiple input and multiple output (MIMO) techniques in optical wireless system helps to increase the capacity of the system and thus improve the system performance. In this paper, we investigate the use of an optical MIMO technique jointly with pulse position modulation (PPM) in order to improve the data rates without reducing the reliability of the link. PPM is known to be signal-to-noise ratio efficient modulation format, while it is bandwidth inefficient so the use of MIMO can compensate that drawback with reasonable complexity. Furthermore, an offline tool for VLC system planning, including error probability and transmission rate, has been proposed in order to solve the tradeoff between transmission rate and error rate. Finally, several numerical results and performance comparisons are reported.

    Authors (5):
    • Mauro Biagi,
    • Anna Maria Vegni,
    • Stefano Pergoloni,
    • Pankil Butala,
    • Thomas DC Little
  • Multi-wavelength visible light communication system design

    IEEE, Globecom Workshop on Optical Wireless Communications (OWC)

    2014

    Visible light communication (VLC) is achieved by modulation of one or more spectral components in the visible spectrum (380-780 nm). The use of this range provides an opportunity to exploit an otherwise untapped medium that is used in human lighting. Most VLC systems constructed to date focus on using a broad visible band generated by phosphor converted light emitting diodes, or by filtering to isolate the blue component from these sources. Multi-wavelength systems consider additional wavelength bands that are combined to produce the desired communications capacity and lighting output. This color combining, or mixing, realizes desired color temperature and intensity and represents a form of wavelength division multiplexing. This paper investigates the relationships between the colors comprising the lighting source for a range of lighting states, the spectral separation of communication channels, the relative intensities required to realize lighting states, how modulation can be most effectively mapped to the available color channels, and the design of an optical filtering approach to maximize signal to noise ratio while minimizing crosstalk at the receiver. Simulation results based on a three colored VLC system are discussed using orthogonal frequency division multiplexing for each color. It is shown that the system is the most power efficient at 6250 K correlated color temperature, with transmitter spectral spread of 5 nm and filter transmittance width of 40 nm.

    Authors (4):
    • Pankil Butala,
    • Hany Elgala,
    • Pankil Butala,
    • Pankil Butala
  • Sample indexed spatial orthogonal frequency division multiplexing.

    Chinese Optics Letters

    June 2014

    Optical spatial modulation (OSM) is a multiple-transmitter technique that can provide higher data rates with low system complexity as compared with single-input single-output systems. Orthogonal frequency division multiplexing (OFDM) is widely implemented to achieve better spectral efficiency in wireless channels. Asymmetrically clipped optical OFDM (O-OFDM) and DC-biased O-OFDM are two well-known O-OFDM techniques suitable for intensity-modulation direct-detection optical systems. In this work, sample indexed spatial OFDM (SIS-OFDM) is proposed to combine OSM and O-OFDM in a novel way and achieve significant performance gain. By assigning time-domain samples of the O-OFDM transmit symbol to different transmitters, SIS-OFDM achieves much better spectral efficiency and reduces computational complexity at the transmitter as compared with previous work that combines OSM with O-OFDM in the frequency domain. We also consider the impact of optical source biasing on overall performance, and the relative performance of imaging receiver (ImR) versus non-imaging receiver (NImR) design for our proposed SIS-OFDM technique. Results indicate that for an Ntx × Nrx multiple-input multiple-output configuration where Ntx = Nrx = 4, SIS-OFDM using ImR can achieve up to 135 dB of signal-to-noise ratio gain over comparable system using a NImR. Also, using Nsc number of O-OFDM subcarriers provides up to Nsc × log2(Ntx) additional bits per symbol of spectral efficiency over techniques that combine OSM and O-OFDM in the frequency domain.

    Authors (3):
    • Pankil Butala,
    • Hany Elgala,
    • Pankil Butala
  • Performance of optical spatial modulation and spatial multiplexing with imaging receiver

    IEEE Wireless Communications and Networking Conference (WCNC)

    2014

    Abstract: Spatial modulation (SM) and spatial multiplexing (SMP) are two multiple-input multiple-output (MIMO) techniques for transmitting data over an indoor optical wireless channel. Receivers for SM and SMP can be of the non-imaging type, in which case the channel matrix coefficients can be highly correlated, or of the imaging type, which can reduce the degree of correlation and improve overall system performance. In this work, we propose a new framework to analyze the performance of imaging MIMO systems. This framework is applied to characterize the performance of SM and SMP under both imaging and non-imaging receivers. Results of our analysis indicate that imaging receivers can provide significant signal-to-noise ratio (SNR) improvements up to 45dB under SM and SMP as compared to the use of non-imaging receivers. Finally, the application of the proposed analysis framework indicates specific design principles to optimize imaging receiver parameters.

    Authors (3):
    • Pankil Butala,
    • Pankil Butala,
    • Pankil Butala
  • SVD-VLC: A novel capacity maximizing VLC MIMO system architecture under illumination constraints

    IEEE, Globecom Workshop on Optical Wireless Communications (OWC)

    December 2013

    Abstract: Multiple-input multiple-output (MIMO) systems using multiple light emitting diode (LED) sources and photodiode (PD) detectors are attractive for visible light communication (VLC) as they offer a capacity gain proportional to the number of parallel single-input single-output (SISO) channels. MIMO VLC systems exploit the high signal-to-noise ratio (SNR) of a SISO channel offered due to typical illumination requirements to overcome the capacity constraints due to limited modulation bandwidth of LEDs. In this work, a modified singular value decomposition VLC (SVD-VLC) MIMO system is proposed. This system maximizes the data rate while maintaining the target illumination and allowing the channel matrix to vary in order to support mobility in a practical indoor VLC deployment. The upper bound on capacity of the proposed SVD-VLC MIMO system is calculated assuming an imaging receiver. The relationship between the proposed system performance and system parameters total power constraint, lens aperture and random receiver locations are described.

    Authors (3):
    • Pankil Butala,
    • Pankil Butala,
    • Pankil Butala
  • Metameric modulation for diffuse visible light communications with constant ambient lighting

    IEEE, International Workshop on Optical Wireless Communications (IWOW)

    October 2012

    Abstract: Advances in solid-state lighting are renewing interest in the adoption of the visible spectrum for optical wireless communications. Under the luminaire-as-transmitter model, wireless communication is achieved by modulating LED(s) that must simultaneously meet the illumination mission. Illumination requirements include maintaining energy efficiency, constant color and intensity control whereas communications requirements are speed and BER goals. In this paper we explore the perceptual qualities of visible light from LED luminaires to render color. We then propose a novel modulation scheme for visible light communications which can maintain constant perceived ambient lighting. By using D>;3 LEDs, multiple lighting states that are indistinguishable to humans but are distinguishable to an electronic receiver can be achieved. Changes between these states are detected as intensity modulation in different wavelength bands.

    Authors (3):
    • Pankil Butala,
    • Pankil Butala,
    • Pankil Butala
  • Monitoring walking and cycling of middle-aged to older community dwellers using wireless wearable accelerometers

    IEEE, International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)

    August 2012

    Abstract: Changes in gait parameters have been shown to be an important indicator of several age-related cognitive and physical declines of older adults. In this paper we propose a method to monitor and analyze walking and cycling activities based on a triaxial accelerometer worn on one ankle. We use an algorithm that can (1) distinguish between static and dynamic functional activities, (2) detect walking and cycling events, (3) identify gait parameters, including step frequency, number of steps, number of walking periods, and total walking duration per day, and (4) evaluate cycling parameters, including cycling frequency, number of cycling periods, and total cycling duration. Our algorithm is evaluated against the triaxial accelerometer data obtained from a group of 297 middle-aged to older adults wearing an activity monitor on the right ankle for approximately one week while performing unconstrained daily activities in the home and community setting. The correlation coefficients between each of detected gait and cycling parameters on two weekdays are all statistically significant, ranging from 0.668 to 0.873. These results demonstrate good test-retest reliability of our method in monitoring walking and cycling activities and analyzing gait and cycling parameters. This algorithm is efficient and causal in time and thus implementable for real-time monitoring and feedback.

    Authors (9):
    • Yuting Zhang,
    • Pankil Butala,
    • Pankil Butala,
    • Pankil Butala,
    • Pankil Butala,
    • Pankil Butala,
    • Pankil Butala,
    • Pankil Butala,
    • Pankil Butala
  • Wireless system for monitoring and real time classification of functional activity

    IEEE, International Conference on Communication Systems and Networks (COMSNETS)

    January 2012

    Abstract: The ubiquity of smartphones and their capability to support complex data collection, processing and communications applications is leading to a revolution in personal healthcare. Always `on’ and carried, and seamlessly connected to multiple network technologies such as WiFi, Bluetooth, and cellular carrier, these devices can be adopted as hub for aggregating data sourced from custom body-worn sensors. To be effective, however, these devices must balance the diverse design specifications for intermittent smart phone use with the real-time characteristic of health monitoring telemetry. In this paper we focus on the development of sensing devices supporting in-home and community-based health monitoring. We describe the design of a low powered, compact, wireless, and customizable platform for wearable activity monitoring. Of particular importance in this design is the ability to achieve sufficient spatial and temporal sampling resolution for the activity detection mission while meeting battery size and longevity constraints. The sensor design is paired with data aggregation using a WPAN and smartphone to support a body worn network capable of interaction with local telemetry to provide continuous functional activity monitoring, real time activity classification, and notification. Predicted and measured performance data indicate satisfaction of the mission with huge potential gains after optimization of sampling strategies.

    Authors (4):
    • Pankil Butala,
    • Yuting Zhang,
    • Pankil Butala,
    • Pankil Butala

Projects

  • Wearable Functional Activity Monitor for Elderly Healthcare

    May 2010 – May 2013

    Team Members (5):
    • Pankil Butala,
    • Pankil Butala,
    • Pankil Butala,
    • Pankil Butala,
    • Pankil Butala

Patents

  • Disclosed herein is an illumination system including an array of LED light sources for emitting light encoded with a modulation pattern, an array of sensors and a space characterization unit. The array of sensors receives emitted light scattered by an object. Each sensor determines a distance between the corresponding light source and the object using the modulation pattern. The space characterization unit uses the distance from each sensor to generate an elevation map indicating a presence of the object.

    Inventors (5):
    • Pankil Butala,
    • ,
    • ,
    • Thomas DC Little,

Skills & Expertise

  • Electronics
  • Wireless Communications Systems
  • Computer Networking
  • Algorithms
  • Matlab
  • Labview
  • Signal Processing
  • Simulations
  • Biomedical Engineering
  • Systems Engineering
  • Wireless
  • C#
  • Embedded Software
  • Image Processing
  • Digital Signal Processing
  • LabVIEW
  • Field-Programmable Gate Arrays (FPGA)
  • Wireless Technologies
  • Engineering Management
  • Embedded Systems
  • FPGA
  • LaTeX
  • Networking
  • C
  • OFDM
  • C++
  • Product Development
  • Information Theory
  • Simulink
  • Coding Theory
  • Physical Layer
  • Programming
  • MIMO
  • Modulation

Volunteer Experience & Causes

Causes Pankil cares about:

  • Education
  • Environment
  • Health
  • Science and Technology