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A 4-bit, 10 gigasamples per second (Gsps) analog-to-digital converter (ADC) printed circuit board (PCB) was designed and manufactured for digitizing radio telescopes. Associated with the field-programmable gate array (FPGA) platform developed by the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER) community, the developed PCB provides data acquisition systems with a...
This paper is concerned with distributed estimation of a scalar parameter using a wireless sensor network (WSN) that employs a large number of sensors operating under limited bandwidth resource. A semi-orthogonal multiple-access channel (MAC), which provides transmission of observations from K sensors to a fusion center (FC) via N (N ≤ N) orthogonal channels, is studied. The K sensors are divided...
Mutual coupling among receive antennas can profoundly reduce the ergodic capacity of MIMO systems. Prior work has shown that these losses can often be mitigated by using multi-port antenna matching at the receiver; however, previous studies have focused exclusively on frequency-nonselective matching and rely on assumptions which are valid only for small bandwidths. In this paper, we revisit the ergodic...
This paper proposes a novel approach for data-compression using Delta-sigma modulator (ΔΣ-M) and applies it to design bit-stream based controllers. An adaptive scheme is introduced to automatically determine the upper and lower boundaries of the quantizer of the ΔΣ-M. The stability condition of the feedback control system with embedded ΔΣ-M is derived analytically based on sliding mode analysis. The...
This work presents Direct-Digital Frequency Synthesis architectures based on the classical Pulse-Direct Digital Synthesizer and using two quantization paths with opposite dithers or multi-path quantization with independent dithers to achieve spurs-free output with improved dynamic range. The proposed architectures are studied mathematically and the theory is supported by MATLAB simulation results.
In this paper, we study the optimal tracking performance problem of continuous-time linear multi-input multi-output (MIMO) networked control systems. The unstable and non-minimum phase systems is considered. The output feedback path is subject to quantization noise, additive white Gaussian noise and bandwidth constraints, and encoding and decoding are considered. The reference input is a random signal...
In this paper, a low-noise amplifier (LNA) designed for the lower band of the ultra-wideband (UWB) spectrum and implemented in 0.18 μm CMOS process is presented. Post-layout simulations show a power gain (S21) of 11.18 dB with 0.8 dB value variations from 259 MHz to 5 GHz. The input and output return losses, S11 and S22, are below −10 dB from 466.4 MHz to 5.63 GHz, while reverse isolation (S12) is...
An ultra wideband (UWB) low nose amplifier (LNA) is presented in this paper. It is designed to operate in the complete range (3–10 GHz) as defined by the US Federal Communications Commission (FCC) using the 130 nm CMOS technology process. The main goals of the design are low noise, high linearity and low variance of the gain over the operating frequency range. To achieve this, the two stage topology...
A novel high impedance JFET high voltage follower combined with ADC driver and a dedicated error compensation feedback is discussed in this paper. Proposed circuit builds around required ADC driver and its transfer curve by adding few low cost components to turn it into a high impedance input ADC driver with high voltage capability and error compensation ability. Such a circuit is applicable in instrumentation...
Waveform design over two consecutive transmission time instants or epochs is the focus of this paper. The waveforms are designed to maximize the mutual information (MI) over the two time epochs. For a single epoch, maximizing the MI is equivalent to waterfilling. In this paper it is shown that for two epochs, the designed waveforms must satisfy two criteria. The first is waterfilling, and the other...
In this paper, fundamental theory has been developed for the harmonic oscillators. The gain-bandwidth product and the expected quality factor of a simple-tuned oscillator have been defined and explained. Additive noise is modeled to describe the spectral components at short-term stability. Also here, the amplitude and phase modulation spectra of a harmonic oscillator are extended to the Fourier domain...
A potential technology by substrate interposer enables high bandwidth and low power application processing devices of the future, because the demand of smart mobile products are driving for higher logic-to-memory bandwidth (BW) over 30 GB/s with lower power consumption and ultra-capacity of memory. This paper presents a new High Bandwidth Package-on-Package (HB-PoP) structure with substrate interposer...
A new ultra-low power fully recycling folded cascode amplifier with low supply voltage is presented. The new configuration benefits from higher transconductance, slew rate and gain in comparison with conventional recycling folded cascode. Furthermore, the phase-margin is enhanced and the input referred noise is reduced in this new configuration. Simulation results in standard 0.18 μm CMOS technology...
An analog front-end circuit of analog-to-digital converter (ADC) is one of critical parts, which defines a performance of high-speed signal acquisition boards/systems. It directly influences following characteristics of system: frequency response, noise floor, transient response, over drive recovery. The analog front-end circuit for 500 MSPS 12-bit ADC has been developed, and it features best-in-class...
We1 propose two methods for the detection of RF interference. The first one is for the detection of the interferences from microwave ovens, and the second one is for Wi-Fi and Bluetooth signals. The motivation of this work is to design a system for reliable wireless communication. Specifically, the systems equipped with interference detectors will be able to choose the appropriate time intervals to...
In wireless cellular networks, multiple scenarios involve the communication between devices located in the same vicinity. These links can be offloaded to a device to device (D2D) underlay which is controlled by the cellular infrastructure. Such an option alleviates the load on the base stations and saves spectrum resources for downlink connections. In this paper, we investigate the impact of D2D communications...
Wireless LANs, especially WiFi, have been pervasively deployed and have fostered myriad wireless communication services and ubiquitous computing applications. A primary concern in designing each scenario-tailored application is to combat harsh indoor propagation environments, particularly Non-Line-Of-Sight (NLOS) propagation. The ability to distinguish Line-Of-Sight (LOS) path from NLOS paths acts...
Compressed Sensing (CS) is a new mathematical concept, which can reconstruct the original signal accurately with lower Nyquist sampling. Besides, multipath arrivals in an Ultra-wideband (UWB) channel have a long time intervals between clusters and rays where the signal takes on zero or negligible values. It is precisely this signal sparsity of the impulse response of the UWB channel that is suitable...
Smart meters are integral to demand response in emerging smart grids, by reporting the electricity consumption of users to serve application needs. But reporting real-time usage information for individual households raises privacy concerns. Existing techniques to guarantee differential privacy (DP) of smart meter users either are not fault tolerant or achieve (possibly partial) fault tolerance at...
It is believed that the time-domain resolution of a digital signal edge transition is superior to the voltage resolution of an analog signal in advanced CMOS processes[1], [2]. The reasoning behind this is that operating voltage has been reducing, making the signal more vulnerable to noise power due to scaling. On the other hand, in time domain, scaling has resulted to increase in frequency and therefore...
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