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This dissertation explores a few techniques to realize a low-cost monolithic fiber-optic receiver with large-area photo detectors in advanced CMOS processes that could potentially support multi-gigabit digital data across 10 to 20 meters plastic optical fibers (POF). The first techniques investigated in this dissertation are the use of an external pseudo-differential photo detector chip to reduce the impact of the inductive parasitics, and the use of a cross-coupled regulated-cascode (CC-RGC) buffer to relieve the DC voltage headroom issues found in conventional regulated-cascode (RGC) buffers in technologies with low power supply voltages. The second technique investigated in this thesis is the super-Gm transimpedance amplifier (SGM-TIA) that can be used to produce a very small input impedance in order to drive a very large parasitic capacitance exhibited by an integrated photo detector in advanced CMOS processes. The third technique investigated is a linear equalizer with multiple shunt-shunt feedbacks that can be utilized to produce a slowly-rising peaking response in order to compensate for the frequency-dependent losses exhibited by the integrated NW/P-sub photo detector. Two prototype POF receiver test chips have been implemented in TSMC’s 65 nm CMOS processes and non-return-to-zero optical data transmissions have been demonstrated at data rates up to 3.125 Gbps and 4.25 Gbps, respectively, with a 2.5 Gbps grade 670 nm vertical-cavity surface-emitting laser based electro-optical transmitter.

This dissertation explores a few techniques to realize a low-cost monolithic fiber-optic receiver with large-area photo detectors in advanced CMOS processes that could potentially support multi-gigabit digital data across 10 to 20 meters plastic optical fibers (POF). The first techniques investigated in this dissertation are the use of an external pseudo-differential photo detector chip to reduce the impact of the inductive parasitics, and the use of a cross-coupled regulated-cascode (CC-RGC) buffer to relieve the DC voltage headroom issues found in conventional regulated-cascode (RGC) buffers in technologies with low power supply voltages. The second technique investigated in this thesis is the super-Gm transimpedance amplifier (SGM-TIA) that can be used to produce a very small input impedance in order to drive a very large parasitic capacitance exhibited by an integrated photo detector in advanced CMOS processes. The third technique investigated is a linear equalizer with multiple shunt-shunt feedbacks that can be utilized to produce a slowly-rising peaking response in order to compensate for the frequency-dependent losses exhibited by the integrated NW/P-sub photo detector. Two prototype POF receiver test chips have been implemented in TSMC’s 65 nm CMOS processes and non-return-to-zero optical data transmissions have been demonstrated at data rates up to 3.125 Gbps and 4.25 Gbps, respectively, with a 2.5 Gbps grade 670 nm vertical-cavity surface-emitting laser based electro-optical transmitter.

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In this thesis, we evaluate the performance of multi-user detectors over an uplink using AWGN, Rayleigh flat fading single-input single-output (SISO) and multiple-input multiple-output (MIMO) channel models. First, we review the performance of three multiuser receivers; the decorrelator, the MMSE receiver and the multistage parallel interference cancellation receiver in an AWGN and Rayleigh flat fading SISO channel. Next, the V-BLAST algorithm is reviewed and the error propagation of this algorithm is investigated. Then, the V-BLAST algorithm is combined with multiuser receivers to achieve high channel capacity while sharing the spectral resources over a MIMO channel. A bias reduction technique is considered for multistage parallel interference cancellation receiver on both SISO and MIMO channel. Finally, the effect of channel estimation error and timing delay estimation error is evaluated for MIMO systems with multiple users. / Master of Science

A 12 channel real-time GPS L1 C/A-code software receiver has been implemented on a Desktop with 1.84GHz Intel CPU. The software receiver has the capability to acquire new satellites coming in, keep tracking of satellites in view and give a user solution accuracy of 30 meters. This study also explores a real-time correlator for the GLONASS L1 signals. This software receiver is going to be used for scientific research and education. This work is a part of the ongoing effort to develop a low-cost, flexible, and capable GNSS receiver for use as a scientific instrument and for GNSS receiver technology development. The software receiver developed here makes use of a reconfigurable RF front end called the Universal Software Radio Peripheral (USRP) with a maximum real sampling frequency of 8MHz of complex samples. The USRP uses interchangeable daughter boards to down-convert and digitize RF signals in the range of DC to 2.9GHz, where each daughterboard covers an overlapping subset of this range. This RF front end was chosen for its flexibility and ease of use. The output of the RF front end is 8-bit complex I/Q samples output via a USB cable. The software receiver processing of the RF front-end outputs is accomplished by using bit-wise parallelism, as described in References [1] and [2]. In order to process the incoming RF data in this manner, the 8-bit complex I/Q samples are quantized to two bits. This is performed in the software receiver prior to signal correlation. In-phase and quadrature accumulations are computed using bit-wise parallel techniques, and these accumulations are used to drive code tracking delay-lock loops (DLLs) and carrier tracking phase-lock loops(PLLs). The computation of accumulations and the implementation of DLLs and PLLs for the GNSS ranging signals are detailed in the thesis. The software receiver is developed by C++. It consists of two parts: the software receiver core program and a simple interface. The current software receiver runs under Ubuntu Linux systems, but it is convenient to implement on other Linux systems. The software prerequisites for the software receiver are GNUradio and QT4.0. GNUradio is an open source program which provides the driver for the USRP board. The current version used by the software receiver is GNUradio-3.1.3. The user interface program is developed by using the classes provided by QT4.0. The hardware of the whole system consists of computer with intel 1.84 GHz CPU and 2GHz RAM, GPS and GLONASS antenna, USRP, and analogue signal generator. One problem with the USRP is that its on-board oscillator is not particularly stable in terms of frequency and phase. One solution to this problem is to use a high-quality external oscillator. An Agilent N5181A MXG Analog Signal Generator configured to output a 64MHz signal has been used as an external input clock to the USRP. This oscillator has a stated frequency error of 1 ppm/yr, has decent short-term frequency stability, and has a reasonably low phase noise at 64MHz. The outputs of the USRP board are 8 bits complex data with 4MHz sampling frequency with an intermediate frequency of zero. The input data are re-quantized and pack into 32-bit of integers. The total CPU usage of the software receiver is about 30 ~ 40% of the 1.84GHz CPU. The software receiver is started with a FFT based acquisition. The acquisition results are then used to initialize the receiver. The background search of satellites is accomplished by a serial search of PRN code replicas. The novelty of the the software receiver developed in this study is as follows: first, a reconfigurable RF front end is used which makes the software receiver extendable.Second, The software is developed with C++ in the general Linux system; This will make the software receiver easy to maintain and update. Third, the current software receiver also explores the process of GLONASS L1 signals with bit-wise parallel correlation. / Master of Science

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The selection of the Intermediate Frequency (IF) bandwidth filter for a data receiver for processing PCM data is based on using a peak deviation of 0.35 times the bit rate. The optimum IF bandwidth filter is equal to the bit rate. An IF bandwidth filter of 1.5 times the bit rate degrades the data by approximately 0.7 dB. The selection of the IF bandwidth filter for tracking receivers is based on the narrowest “noise bandwidth” that will yield the best system sensitivity. In some cases the noise bandwidth of the tracking receiver is the same as the IF bandwidth of the data receiver because it is the same receiver. If this is the case, the PCM bit rate determines the IF bandwidth and establishes the system sensitivity. With increasing bit rates and increased transmitter stability characteristics, the IF bandwidth filter selection criteria for a tracking receiver must include system sensitivity considerations. The tracking receiver IF bandwidth filter selection criteria should also be based on the narrowest IF bandwidth that will not cause the tracking errors to be masked by high bit rates and alter the pedestal dynamic response. This paper describes a selection criteria for a tracking receiver IF bandwidth filter based on measurements of the tracking error signals versus antenna pedestal dynamic response. Different IF bandwidth filters for low and high bit rates were used.

abstract: The universe since its formation 13.7 billion years ago has undergone many changes. It began with expanding and cooling down to a temperature low enough for formation of atoms of neutral Hydrogen and Helium gas. Stronger gravitational pull in certain regions caused some regions to be denser and hotter than others. These regions kept getting denser and hotter until they had centers hot enough to burn the hydrogen and form the first stars, which ended the Dark Ages. These stars did not live long and underwent violent explosions. These explosions and the photons from the stars caused the hydrogen gas around them to ionize. This went on until all the hydrogen gas in the universe was ionized. This period is known as Epoch Of Reionization. Studying the Epoch Of Reionization will help understand the formation of these early stars, the timeline of the reionization and the formation of the stars and galaxies as we know them today. Studying the radiations from the 21cm line in neutral hydrogen, redshifted to below 200MHz can help determine details such as velocity, density and temperature of these early stars and the media around them. The EDGES program is one of the many programs that aim to study the Epoch of Reionization. It is a ground-based project deployed in Murchison Radio-Astronomy Observatory in Western Australia. At ground level the Radio Frequency Interference from the ionosphere and various man-made transmitters in the same frequency range as the EDGES receiver make measurements, receiver design and extraction of useful data from received signals difficult. Putting the receiver in space can help majorly escape the RFI. The EDGES In Space is a proposed project that aims at designing a receiver similar to the EDGES receiver but for a cubesat. This thesis aims at designing a prototype receiver that is similar in architecture to the EDGES low band receiver (50-100MHz) but is significantly smaller in size (small enough to fit on a PCB for a cubesat) while keeping in mind different considerations that affect circuit performance in space. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2019

ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / The Army Research Laboratories has developed a PCM/FM telemetry receiver using a low-cost commercial software-defined radio (SDR). Whereas traditional radio systems are implemented in hardware, much of the functionality of software-defined radios is defined in software. This gives them the flexibility to accommodate military telemetry standards as well as other specialized functions. After a brief review of telecommunication theory, this paper describes the receiver implementation on a commercial SDR platform. Data rates up to 10 Mbs were obtained through the customization the SDR's field programmable gate array.

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / Shaped Offset QPSK (SOQPSK), as proposed and analyzed by Terrance Hill, is a family of constant envelope waveforms that is non-proprietary and exhibits excellent spectral containment and detection efficiency. Detection results using the filtering found in conventional OQPSK demodulators have been published for two variants of SOQPSK, namely SOQPSK-A and –B. This paper describes a method of synthesizing an optimal linear detection filter, with regard to bit error probability (BEP), and presents the resulting performance.