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Impulsive noise in power lines usually bears higher power spectral density than the background noise. Even a sample of such noise, if not mitigated, destroys symbols in all the subcarriers affecting channel estimation and information... more
Impulsive noise in power lines usually bears higher power spectral density than the background noise. Even a sample of such noise, if not mitigated, destroys symbols in all the subcarriers affecting channel estimation and information detection. In this paper, we study two maximum-likelihood approaches to estimate the channel in the presence of impulsive noise for an OFDM based PLC system. In both approaches, we approximate the impulsive noise first and use it to determine the channel frequency response. In the first approach, we assume the estimated noise to be random and perform the channel estimation assuming that its statistics are given. In the second approach, the impulsive noise is assumed to be deterministic and the channel frequency response is determined after proper subtraction from the observations. As will be shown by simulation results, the estimator that assumes noise to be random generally performs better than the one that treats the estimated impulsive noise as a det...
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Indoor positioning is currently recognized as one of the important features in emergency, commercial and industrial applications. The 5G network enhances mobility, flexibility, reliability, and security to new higher levels which greatly... more
Indoor positioning is currently recognized as one of the important features in emergency, commercial and industrial applications. The 5G network enhances mobility, flexibility, reliability, and security to new higher levels which greatly benefit the IoT and industrial applications. Industrial IoT (IIoT) use-cases are characterized by ambitious system requirements for positioning accuracy in many verticals. For example, on the factory floor, it is important to locate assets and moving objects such as forklifts. The deployment design for different IIoT environments has a significant impact on the positioning performance in terms of both accuracy and availability of the service. Indoor factory (InF) and indoor open office (IOO) are two available and standardized Third Generation Partnership Project (3GPP) scenarios for evaluation of indoor channel models and positioning performance in IIoT use cases. This paper aims to evaluate the positioning performance in terms of accuracy and avail...
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Perceiving and recognizing material properties of surfaces and objects are fundamental aspects of new and emerging use cases such as robotic perception, virtual reality (VR) applications, digital twins, and creating a 3D digital map of an... more
Perceiving and recognizing material properties of surfaces and objects are fundamental aspects of new and emerging use cases such as robotic perception, virtual reality (VR) applications, digital twins, and creating a 3D digital map of an environment. In this paper, we present results from our simulation-based study of reflection loss-based material identification from eight common building materials. The study focuses on 2.6 GHz, 28 GHz, and 60 GHz radio carrier frequencies. Analysis of simulation results indicates that a combination of incident angle and reflection loss can be used to properly identify the common building materials. We, therefore, propose a novel joint communication and sensing method for material recognition using reflection loss of the radio signal by the scatterers around the propagation path in a wireless communication network. Compared to existing material identification methods, the proposed reflection-loss-based method is capable of identifying materials fr...
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Cellular network technologies and radar sensing technologies have been developing in parallel for decades. Instead of developing two individual technologies, the 6G cellular network is expected to naturally support both communication and... more
Cellular network technologies and radar sensing technologies have been developing in parallel for decades. Instead of developing two individual technologies, the 6G cellular network is expected to naturally support both communication and radar functionalities with shared hardware and carrier frequencies. In this regard, radio access technology (RAT)-based scatterer localization system is one of the important aspects of joint communication and sensing system (JCAS) that uses communication signals between transceivers to determine the location of scatterers in and around the propagation paths. In this article, we first identify the challenges of RAT-based scatterer localization system, then present singleand multiple-bounce reflection loss (RL) simulation results for three common building materials in indoor environments. We also propose two novel methods to jointly localize and identify the type of the scatterers in a rich scattering environment.
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Release 9 specification of the Third Generation Partnership Project (3GPP) provided support to Observed Time Difference of Arrival (OTDOA) based positioning method for UE-Assisted mode using Long Term Evolution (LTE) Radio Access... more
Release 9 specification of the Third Generation Partnership Project (3GPP) provided support to Observed Time Difference of Arrival (OTDOA) based positioning method for UE-Assisted mode using Long Term Evolution (LTE) Radio Access Technology (RAT). Evolving to release 16 specification it has been agreed by 3GPP consortium also to support UE-Based New Radio (NR), popularly known as 5G RAT dependent positioning method. UE-Based positioning methods will enable the device to calculate its location by using the Assistance Data (AD) that are transmitted by the Network. The AD may need to be broadcast and since the broadcast resource is constraint in terms of resources and physical size limit of broadcast channel, the AD should be selected carefully. The selection of data in the AD delivery would play a crucial role for the UE to calculate the location with high accuracy. In order to obtain high precision accuracy, the geometry in terms of UE location and the selection of beams would play a...
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Power line communication (PLC) is considered as the most viable enabler of the smart grid. PLC exploits the power line infrastructure for data transmission and provides an economical communication backbone to support the requirements of... more
Power line communication (PLC) is considered as the most viable enabler of the smart grid. PLC exploits the power line infrastructure for data transmission and provides an economical communication backbone to support the requirements of smart grid applications. Though PLC brings a lot of benefits to the smart grid implementation, impairments such as frequency selective attenuation of the high-frequency communication signal, the presence of impulsive noise (IN) and the narrowband interference (NBI) from closely operating wireless communication systems, make the power line a hostile environament for reliable data transmission. Hence, the main objective of this dissertation is to design signal processing algorithms that are specifically tailored to overcome the inevitable impairments in the power line environment. First, we propose a novel IN mitigation scheme for PLC systems. The proposed scheme actively estimates the locations of IN samples and eliminates the effect of IN only from t...
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Research Interests: Computer Science and IEEE
Joint communication and sensing is emerging as a potential extension to the existing wireless communication systems. In this paper, we present an overview of sensing using a primarily wireless communication network and investigate... more
Joint communication and sensing is emerging as a potential extension to the existing wireless communication systems. In this paper, we present an overview of sensing using a primarily wireless communication network and investigate different design aspects such as hardware implications, spectrum requirements and multiplexing of communication and sensing signals. Also, we present sensing signal design based on the required sensing accuracies for an OFDM-based communication system and show the corresponding detection performance. One interesting finding is the large difference between transmission power of sensing compared to transmission power used for communication. We will discuss how this impacts the design, including duplex direction as well as waveform that is used for sensing. Finally, we discuss some tradeoffs between sensing accuracy and the overhead of sensing signal and solutions to reduce the overhead in a joint communication and sensing system.