86 research outputs found
Delay-Exponent of Bilayer Anytime Code
In this paper, we study the design and the delay-exponent of anytime codes
over a three terminal relay network. We propose a bilayer anytime code based on
anytime spatially coupled low-density parity-check (LDPC) codes and investigate
the anytime characteristics through density evolution analysis. By using
mathematical induction technique, we find analytical expressions of the
delay-exponent for the proposed code. Through comparison, we show that the
analytical delay-exponent has a close match with the delay-exponent obtained
from numerical results.Comment: Accepted for presentation in ITW-2014. 5 Pages, 3 Figure
Finite Length Analysis of LDPC Codes
In this paper, we study the performance of finite-length LDPC codes in the
waterfall region. We propose an algorithm to predict the error performance of
finite-length LDPC codes over various binary memoryless channels. Through
numerical results, we find that our technique gives better performance
prediction compared to existing techniques.Comment: Submitted to WCNC 201
Interference aware optimal power allocation for industrial IoT: A self-triggered approach
One of the key use cases for 5G cellular communication is wirelessly connected smart factory applications as part of the Industry 5.0 vision. Such applications require high throughput, low latency, and highly reliable communication for critical control applications. With limited private spectrum available for Industry 5.0 use cases, scarce wireless network resources (e.g., bandwidth, channel capacity, etc.) need to be used efficiently. In this paper, we optimize wireless channel resources, in particular the secondary control channel, by increasing channel capacity in the presence of interference through power control and self-triggered control (STC) based message transmission. We aim to maximize control channel efficiency and minimize secondary control communication. Our simulation results demonstrate that STC-based communication can achieve the same system performance as periodic communication while preserving about 85% of the control channel bandwidth
Leader-follower-based self-triggered consensus control of industrial induction motor drives
Alternating current motors are critical to industry, as they drive many machines in the manufacturing and processing industries. To accomplish heavy tasks, often, a number of small motors must operate cooperatively, which means that the operation of the motors must be coordinated using, for example, consensus control. To accomplish this, the motors must communicate with each other. This communication can be periodic or event driven. As periodic communication may waste communication resources when no control update is needed, we propose a need-based self-triggered communication (STC) mechanism to achieve improved communication efficiency. We propose an STC technique for the leaderĂ¢ follower-based consensus control of induction motors. To study this method, we developed both centralized and distributed STC models. In the centralized approach, each motor is connected to a central unit that calculates the next communication time. When distributed STC is used, each motor calculates the next communication time solely based on information from directly connected neighboring motors, thus eliminating the possibility of a single point of failure. Extensive simulations were conducted to validate the proposed approaches. Our results show that the proposed self-triggered consensus control technique gets the same level of performance as a standard periodic control approach while utilizing fewer communication resources
Thermodynamically Stable DNA Code Design using a Similarity Significance Model
DNA code design aims to generate a set of DNA sequences (codewords) with
minimum likelihood of undesired hybridizations among sequences and their
reverse-complement (RC) pairs (cross-hybridization). Inspired by the distinct
hybridization affinities (or stabilities) of perfect double helix constructed
by individual single-stranded DNA (ssDNA) and its RC pair, we propose a novel
similarity significance (SS) model to measure the similarity between DNA
sequences. Particularly, instead of directly measuring the similarity of two
sequences by any metric/approach, the proposed SS works in a way to evaluate
how more likely will the undesirable hybridizations occur over the desirable
hybridizations in the presence of the two measured sequences and their RC
pairs. With this SS model, we construct thermodynamically stable DNA codes
subject to several combinatorial constraints using a sorting-based algorithm.
The proposed scheme results in DNA codes with larger code sizes and wider free
energy gaps (hence better cross-hybridization performance) compared to the
existing methods.Comment: To appear in ISIT 202
5G NR-V2X: Towards Connected and Cooperative Autonomous Driving
This paper is concerned with the key features and fundamental technology
components for 5G New Radio (NR) for genuine realization of connected and
cooperative autonomous driving. We discuss the major functionalities of
physical layer, Sidelink features and its resource allocation, architecture
flexibility, security and privacy mechanisms, and precise positioning
techniques with an evolution path from existing cellular vehicle-to-everything
(V2X) technology towards NR-V2X. Moreover, we envisage and highlight the
potential of machine learning for further enhancement of various NR-V2X
services. Lastly, we show how 5G NR can be configured to support advanced V2X
use cases in autonomous driving
Finite-Length Performance Analysis of LDPC Coded Continuous Phase Modulation
Serial concatenation of LDPC codes and continuous phase modulation (CPM) has recently gained significant attention due to its capacity-approaching performance, efficient detection as well as owing to its constant-envelope nature. Most of the previous contributions on LDPC coded CPM were devoted to the design of LDPC codes and their asymptotic performance analysis. However, there is a paucity of work on the finite-length performance estimation of LDPC coded CPM, primarily because existing performance estimation techniques cannot be readily applied to the LDPC coded CPM. To fill this gap, we conceive an analytical bit error probability estimation technique for finite-length LDPC coded CPM in the waterfall region. Numerical results are provided both for regular and irregular LDPC codes having different codeword lengths, demonstrating that the estimated performances are closely matched by the simulated ones
Finite-length performance analysis of LDPC coded continuous phase modulation
Serial concatenation of LDPC codes and continuous phase modulation (CPM) has recently gained significant attention due to its capacity-approaching performance, efficient detection as well as owing to its constant-envelope nature. Most of the previous contributions on LDPC coded CPM were devoted to the design of LDPC codes and their asymptotic performance analysis. However, there is a paucity of work on the finite-length performance estimation of LDPC coded CPM, primarily because existing performance estimation techniques cannot be readily applied to the LDPC coded CPM. To fill this gap, we conceive an analytical bit error probability estimation technique for finite-length LDPC coded CPM in the waterfall region. Numerical results are provided both for regular and irregular LDPC codes having different codeword lengths, demonstrating that the estimated performances are closely matched by the simulated ones
A Survey on Resource Allocation in Vehicular Networks
Vehicular networks, an enabling technology for Intelligent Transportation System (ITS), smart cities, and autonomous driving, can deliver numerous on-board data services, e.g., road-safety, easy navigation, traffic efficiency, comfort driving, infotainment, etc. Providing satisfactory Quality of Service (QoS) in vehicular networks, however, is a challenging task due to a number of limiting factors such as erroneous and congested wireless channels (due to high mobility or uncoordinated channel-access), increasingly fragmented and congested spectrum, hardware imperfections, and anticipated growth of vehicular communication devices. Therefore, it will be critical to allocate and utilize the available wireless network resources in an ultra-efficient manner. In this paper, we present a comprehensive survey on resource allocation schemes for the two dominant vehicular network technologies, e.g. Dedicated Short Range Communications (DSRC) and cellular based vehicular networks. We discuss the challenges and opportunities for resource allocations in modern vehicular networks and outline a number of promising future research directions
Hybrid Chirp Signal Design for Improved Long-Range (LoRa) Communications
Long-range (LoRa) communication has attracted much attention recently due to its utility for many Internet of Things applications. However, one of the key problems of LoRa technology is that it is vulnerable to noise/interference due to the use of only up-chirp signals during modulation. In this paper, to solve this problem, unlike the conventional LoRa modulation scheme, we propose a modulation scheme for LoRa communication based on joint up- and down-chirps. A fast Fourier transform (FFT)-based demodulation scheme is devised to detect modulated symbols. To further improve the demodulation performance, a hybrid demodulation scheme, comprised of FFT- and correlation-based demodulation, is also proposed. The performance of the proposed scheme is evaluated through extensive simulation results. Compared to the conventional LoRa modulation scheme, we show that the proposed scheme exhibits over 3 dB performance gain at a bit error rate of 10−4
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