Team 2002 Final Presentation Uniform Linear Array Implementation - - PowerPoint PPT Presentation

Team 2002 Final Presentation

Uniform Linear Array Implementation using Software Defined Radios

Evan Faulkner, David Sanabria, Sydney Wells Sponsor: The MITRE Corporation Faculty Advisor: Dr. Anwar

Background

• Underwater communication has numerous applications [1]
• The most common solution is to use acoustics [1]
• The underwater acoustic channel presents several challenges [2]
• Beamforming is one of many viable strategies to combat these issues [3]

Peter Willett. ECE 6123 Advanced Signal Processing. Lecture Notes, “Spectral Estimation.” Department of Electrical and Computer Engineering, University of Connecticut, Fall 2017.

Project Goals

• Develop the capability to prototype a Uniform Linear Array (ULA) on a

Software Defined Radio (SDR) platform in a lab environment

• Demonstrate the ability to steer transmissions and receptions using multiple

hydrophone elements

• Evaluate beamforming capability using SDR hardware and wired

connections

Design Considerations

• Beamformer design

○ Time domain vs. frequency domain beamforming ○ Element spacing ○ Number of elements ○ Windowing ○ Steering and Nulling

• SDR Implementation

○ Must run in real time ○ Ettus X310 supports 2 TX channels or 4 RX channels

Hardware

• Provided by MITRE
• Two Ettus X310 USRP software

defined radios to send and receive real signals ○ Two wide-bandwidth daughterboards slots ○ C++/Python driver support

• Two UDOO x86 boards to operate as

Host Computers ○ Windows, Linux, and Android compatible

Technical Solution Phase 1

MATLAB development of beamforming capability in simulated channels

○ AWGN and Stojanovic channels adapted for use with arrays ○ Custom time domain and frequency domain beamformers ○ Testing beamformers for transmission and reception of QPSK signals over AWGN and Stojanovic acoustic channels

Technical Solution Phase 2

Creation of a beamforming application for Ettus X310 SDRs

○ C++ development ○ 2 element transmitter arrays, 4 element receiver arrays ○ Adjustable parameters for windowing, number of elements, sampling rate ○ Unit testing to verify performance is as expected under a range of

• perating conditions

○ Testing transmitter and receiver beamforming over simulated channels ○ Multi-in Multi-out (MIMO) transmission and reception with USRPs

Beamforming Class

• A beamforming class was developed in C++
• A beamformer object is instantiated with the desired geometry
• Methods for transmission and reception in any direction have been developed

○ High sampling rates are assumed allowing use of integer sample delays ○ Transmission takes a single input and generates multiple transmission vectors ○ Reception takes multiple received vectors and outputs a single steered reception vector

• Arbitrary weights can be applied across the array with built-in normalization of

the weight vector

Beamforming Results

Spring 2020 Project Timeline

RACI Chart

Evan Sydney David MITRE

• Dr. Anwar

Matlab Development R R R A I Beamforming R R I A I Rician/Autoregressive Channel R I R A I C++ SDR Development I R R A I Acoustic Communications Research R R R A I Stojanovic Acoustic Channel I I I R I Reports and Presentations R R R C A

References

1) Shengli Zhou and Zhaohui Wang, OFDM for Underwater Acoustic Communications, Hoboken, NJ: John Wiley and Sons, 2014. [E-book] Available: https://learning.oreilly.com/library/view/ofdm-for-underwater/9781118693810/. [Accessed Oct. 17, 2019]. 2) John Heidemann, Milica Stojanovic, and Michele Zorzi, “Underwater sensor networks:applications, advances, and challenges,” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, vol. 370, issue 1958, pp. 158-175. [Online]. Available: https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.2011.0214. [Accessed Oct. 16, 2019]. 3)

• H. L. V. Trees, Optimum Array Processing. New York: John Wiley and Sons, 2002, p. 1-8.

4) Amy Nordrum, “Nato Unveils JANUS, First Standardized Acoustic Protocol for Undersea Systems,” IEEE Spectrum, Jul 17, 2007. [Online]. Available: https://spectrum.ieee.org/tech-talk/telecom/wireless/nato-develops-first-standardized-acoustic-sign al-for-underwater-communications. [Accessed Oct. 16, 2019].

References

5)

• F. Jia, E. Cheng and F. Yuan, "The study on time-variant characteristics of under water acoustic

channels," 2012 International Conference on Systems and Informatics (ICSAI2012), Yantai, 2012, pp. 1650-1654. [Online]. Available: https://ieeexplore.ieee.org/document/6223357. [Accessed on Oct 16, 2019]. 6)

• J. A. Catipovic, "Performance limitations in underwater acoustic telemetry," in IEEE Journal of

Oceanic Engineering, vol. 15, no. 3, pp. 205-216, July 1990. [Online]. Available: https://ieeexplore.ieee.org/document/107149. [Accessed on Oct 17, 2019]. 7) Thesis: Eggen, Trym H., "Underwater acoustic communication over Doppler spread channels", 1997-06, DOI:10.1575/1912/5709, https://hdl.handle.net/1912/5709