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This paper develops a distributed sensor scheduling methodology that utilizes target classification decisions to govern the number of active sensors selected around the target in the deployment region. This approach utilizes a distributed supervisor on each sensor node to control the multi-modal operating state of the node. A distributed sensor selection method is proposed that dynamically adjusts...
This paper addresses the time-optimal path planning problem for underwater vehicles in obstacle-constrained environments. It is assumed that the vehicles can move at variable speeds but their dynamics are subject to bounded curvature and turn rate. We present a novel pose-based search algorithm, which is a modified A∗ algorithm to find time-optimal paths between a given pair of vehicle poses including...
This paper presents an autonomous approach of 3-D reconstruction of underwater terrain using multi-level coverage trees. An autonomous underwater vehicle (AUV) equipped with multi-beam sonar sensors, Doppler velocity log (DVL) and inertial measurement unit (IMU) sensors is used to achieve this goal. The underwater 3-D search space is represented by a multi-level coverage tree which is generated online...
For the first time, an all analog CMA equalizer for DP-QPSK transmission systems has been demonstrated. The experiment with an 8-Gb/s link shows promise for low power analog processing based receivers for short-reach DP-QPSK links.
An optimum solution for a low power and low cost coherent optical receiver design can be obtained by a self homodyne (SH) system that uses analog domain processing. An SH system eliminates the need of a local oscillator (LO) and a carrier phase recovery (CPR) module at the receiver. Due to the inherent line-width tolerance of SH systems, an expensive laser is not required at the transmitter. In digital...
In this paper, we present a methodology to enhance the operating range of a Miller frequency divider. Conventionally Miller frequency dividers are visualized as mixers. We present how injection locking portrait of Miller dividers helps us to understand the dynamics of Miller frequency dividers. Further, we discuss how to enhance the operating range while optimizing the divider between power dissipation...
This paper presents a novel integrated approach of creating a 3-D surface map of seabed terrain using an Autonomous Underwater Vehicle (AUV) equipped with various sensors such as multi-beam sonar sensors, DVL, and IMU. The underwater terrain map is useful for various applications like fishery, search and rescue operations, underwater surveillance, mine hunting, etc. The acoustic sensors mounted on...
This paper presents a complementary CMOS LC quadrature phase oscillator optimized for tuning range and power dissipation. Usage of complementary cross-coupled pair, in addition to series and parallel coupling, helps to reduce the power dissipation while decreasing the tuning range. A method has been proposed for optimizing the trade off between power dissipation and tuning range. With the proposed...
Optimization of high speed coherent optical receivers in terms of power consumption and complexity can be achieved by processing received signals in the analog domain without converting them into the digital domain. At a particular data rate an equalizer based on analog delay cells alone will be limited by the link distance. It is due to the reduction of the overall bandwidth of cascaded delay cells...
Several terabytes of data get generated and transferred through the Internet everyday. With bandwidth-intensive on-line applications such as video, music, and voice the demand for higher data rate increases. The ever-increasing data rate demand will be supported by multilevel signaling over fiber-optic links in the backplane. Traditional coherent optical links use the power hungry ADC+DSP approach...
This paper presents a real-time integrated model of a micro-grid to simulate its electrical energy infrastructure. This infrastructure includes two PV arrays, a fuel cell, and a diesel generator that support building loads when islanded from the utility grid. The paper reviews existing models, which are usually available either as 1) low-level dynamic models, along with power electronics for specific...
The paper presents a novel integration of underwater communication, localization, command and control for the purpose of point-to-point movement of an Autonomous Underwater Vehicle (AUV). An acoustic communication network is used to command the AUV to a desired point within the coordinate frame of the network which provides two-dimensional localization. This information is fused with path planning...
We propose a multi-phase Direct Digital Synthesizer (DDS) based Digital to Time Converter (DTC), for application in fractional-N Digital Phase Locked Loops (DPLLs). The proposed DTC employs (i) multiple DDSs operating with incremental delay for reduced quantization step size, and (ii) a phase-advanced ROM in these DDSs for correct waveform extrapolation. The incrementally delayed output from multiple...
Signal processing in analog domain is an attractive technique for achieving low-power coherent optical link receivers as opposed to DSP (digital signal processing) based receivers. The linear equalizer is one of the most important building blocks in these receivers. An analog domain equalizer requires wideband delay circuits for providing a constant delay with the desired bandwidth. This paper discusses...
We present a 12.5 Gbps 1/5-rate clock and data recovery (CDR) circuit. A time division multiplexed sampling is proposed at the receiver front-end for directly down-sampling the 8b-10b encoded data to 1/5-rate, before the low speed flip-flops (FFs) can be used for retiming the data. This approach helps in reducing the power consumption significantly. A delay locked loop (DLL) is also used for generating...
In phase locked loops, settling time and tuning range form important performance parameters, in addition to jitter and power consumption. However, most PLLs are designed for improvement only in jitter and power, thus resulting in longer settling time. This work proposes an offset-frequency based fractional-N DPLL for generating frequency in the range of 4.7 GHz-5 GHz. The proposed PLL employs (i)...
We design and simulate a novel Silicon Photonic Integrated Transceiver circuit for data transmission by multiplexing of random spatial modes in a multi-mode fiber (MMF) and data recovery using adaptive signal processing at the receiver.
One of the significant issues in coherent optical communication systems is the frequency offset between the carrier laser and the local oscillator (LO) laser. For the synchronization of the phase and frequency between the two lasers a carrier phase recovery and compensation (CPRC) circuit is required. A CPRC circuit that has a phase detector alone may fail to recover the carrier signal if the frequency...
To cater to the demand for ever increasing Internet traffic, on-off keying over multi-mode fiber is expected to be replaced with coherent signaling over single mode fiber in short-reach optical interconnects. One of the key challenges faced at the receiver-end is the recovery of the frequency and phase of the transmitter laser. We propose a novel frequency detector that uses sine-cosine sampling method...
Chip-on-board (COB) printed circuit boards (PCB) appear to be a very attractive solution for testing high-speed integrated circuits (IC). Attaching the bare die directly on a PCB takes away the packaging cost, which is as high as the chip fabrication cost or more when it comes to the high-speed ICs. Wafer probing is a good alternative, but may not come in handy if there are too many high-speed signals...
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