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ADVANCED ANALOG SIGNAL PROCESSING FOR WIRELESS COMMUNICATIONS

Wang, Yingying
http://orcid.org/0000-0002-0637-8683
http://rave.ohiolink.edu/etdc/view?acc_num=case1585776428631869

Abstract Details

2020, Doctor of Philosophy, Case Western Reserve University, EECS - Electrical Engineering.
In this dissertation, I present two examples of advanced signal processing for wireless communications. The first example presents an electronic cochlear, which mimics the exponentially-tapered structure of the biological inner ear using a bidirectional transmission line. The biological inner ear, or cochlea, is a sophisticated signal processing system that performs spectrum analysis over an ultra-broadband frequency range of ~20 Hz to 20 kHz with exquisite sensitivity and high energy efficiency. The bio-inspired electronic cochlear models act as fast and hardware-efficient spectrum analyzers at both audio and radio frequencies. This dissertation describes a cochlea-based digitally-programmable single-chip radio frequency (RF) spectrum analyzer in the 65 nm CMOS process. This "RF cochlea" chip includes a transmission-line active cochlear model with 50 parallel exponentially-spaced stages that analyze the radio spectrum from 1.0-8.3 GHz. The outputs of all stages are encoded in parallel as delta-sigma (Δ-Σ) modulated digital signals for real-time demodulation and analysis by a digital back-end processor. The chip consumes 418 mW and typically generates ~1 GS/s of total data at an ENOB of 5-6 bits. An artificial intelligence (AI)-driven single-channel cognitive radio (CR) receiver based on the RF cochlea has also been implemented and tested. Experimental results show i) good over-the-air modulation recognition (MR) accuracy for several common modulation schemes using a deep belief network (DBN), and ii) autonomous self-optimization of the cochlear chip. Finally, we demonstrate the cochlea's capability in source localization by successfully extracting interaural time difference (ITD) from the cochlea in ideal and realistic environment. The second example exploits multi-dimensional signal processing methods which extend Δ-Σ modulation into the two-dimensional (2-D) space, time case. The proposed 2-D noise-shaping methods employ lossless discrete integrators (LDIs) to reduce the spectral overlap of the regions of support (ROSs) of array signals with that of both thermal and quantization noise in microwave and mm-wave array processing systems. Spatio-temporal low-pass filtering can then be used to improve the overall noise figure, linearity, and resolution of the resulting N-port receiver. A proof-of-concept 65-port receiver that uses first-order Δ-Σ; within both the low-noise amplifier (LNA) and analog-to-digital converter (ADC) has been designed in the UMC 65 nm CMOS process. Detailed circuit simulations with wideband RF inputs at a center frequency of 4 GHz confirm that the proposed 2-D noise-shaping approach provides significant improvements in noise, linearity, and resolution. Specifically, noise figure (NF) improves by 1.5 dB, IIP3 improves by 15 dB, and the effective number of bits (ENOB) improves by 3.1 bits. This novel delta-sigma (Δ-Σ) noise-shaping method could also be extended to three dimensions: 2-D space and time. We show that a spatially-oversampled Nx x Ny antenna array coupled to a noise-shaped LNA and ADC can diminish in-band additive noise and distortion by shaping the multi-dimensional spectrum towards higher spatial frequencies that are outside the ROSs of all possible propagating electromagnetic waves. Detailed circuit simulations in the 65 nm CMOS process with wideband RF inputs at a center frequency of 4 GHz confirm that the proposed 3-D noise-shaping approach also provides significant improvements in noise figure and resolution for 2-D array receivers.
Soumyajit Mandal, Dr. (Committee Chair)
Pedram Mohseni, Dr. (Committee Member)
Hossein Miri Lavasani, Dr. (Committee Member)
Xiong (Bill) Yu, Dr. (Committee Member)
Electrical Engineering

Recommended Citations

Citations

  • Wang, Y. (2020). ADVANCED ANALOG SIGNAL PROCESSING FOR WIRELESS COMMUNICATIONS [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1585776428631869

    APA Style (7th edition)

  • Wang, Yingying. ADVANCED ANALOG SIGNAL PROCESSING FOR WIRELESS COMMUNICATIONS. 2020. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1585776428631869.

    MLA Style (8th edition)

  • Wang, Yingying. "ADVANCED ANALOG SIGNAL PROCESSING FOR WIRELESS COMMUNICATIONS." Doctoral dissertation, Case Western Reserve University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1585776428631869

    Chicago Manual of Style (17th edition)

case1585776428631869
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© 2020, all rights reserved.
This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.