Qasim Ahmed

Qasim Ahmed
University of Huddersfield · Department of Engineering and Technology

PhD

About

77
Publications
11,695
Reads
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638
Citations
Citations since 2017
43 Research Items
525 Citations
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2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150
Additional affiliations
June 2011 - June 2014
King Abdullah University of Science and Technology
Position
  • PostDoc Position
June 2011 - June 2014
King Abdullah University of Science and Technology
Position
  • PostDoc Position
November 2009 - July 2011
National University of Computer and Emerging Sciences
Position
  • Professor (Assistant)

Publications

Publications (77)
Article
Full-text available
Simultaneous localization and mapping (SLAM) algorithm has enabled the automation of mobile robots in unknown environments. It enables the robot to navigate through an unknown trajectory by employing sensors that provide measurements to infer the surrounding environment and use this information to localize the robot. Sensor technology plays a key r...
Article
Non-Line-of-Sight (NLoS) propagation condition is a crucial factor affecting the precision of the localization in the Ultra-Wideband (UWB) Indoor Positioning System (IPS). Numerous supervised Machine Learning (ML) approaches have been applied for NLoS identification to improve the accuracy of the IPS. However, it is difficult for existing ML approa...
Article
Full-text available
Machine Learning (ML) on the edge is key for enabling a new breed of IoT and autonomous system applications. The departure from the traditional cloud-centric architecture means that new deployments can be more power-efficient, provide better privacy and reduced latency for inference. At the core of this paradigm is TinyML, a framework allowing the...
Article
Full-text available
This paper proposes low complexity detection for internet of underwater things communication. The signal is transmitted from the source to the destination using several sensors. To simplify the computational operations at the transmitter and the sensory nodes, a single carrier frequency domain equalizer is proposed and amplify-and-forward protocols...
Article
Full-text available
A design of a low-profile and printed array antenna for wireless access points and futuristic healthcare devices is presented in this manuscript. The antenna design is derived from a printed dipole configuration and is optimized using an empirical design approach to achieve enhanced bandwidth, gain and efficiency performances. The antenna is printe...
Article
Full-text available
The existing sub-6 GHz band is insufficient to support the bandwidth requirement of emerging data-rate-hungry applications and Internet of Things devices, requiring ultrareliable low latency communication (URLLC), thus making the migration to millimeter-wave (mmWave) bands inevitable. A notable disadvantage of a mmWave band is the significant losse...
Preprint
Full-text available
Device-to-device (D2D) or Sidelink aided communication is regarded as one of the most promising technologies to improve the spectral efficiency of the 5G and beyond communication system. However, two main challenges exist: 1) the selection of the optimal number of devices for improving the spectral efficiency, and 2) improving the physical layer se...
Preprint
Full-text available
Device-to-device (D2D) or Sidelink aided communication is regarded as one of the most promising technologies to improve the spectral efficiency of the 5G and beyond communication system. However, two main challenges exist: 1) the selection of the optimal number of devices for improving the spectral efficiency, and 2) improving the physical layer se...
Article
Full-text available
Device-to-device (D2D) or Sidelink aided communication is regarded as one of the most promising technologies to improve the spectral efficiency of the 5G and beyond communication system. However, two main challenges exist: 1) the selection of the optimal number of devices for improving the spectral efficiency, and 2) improving the physical layer se...
Article
Full-text available
The deployment of the Millimeter-Wave (mm-Wave) band in 5G and beyond wireless communications networks is one of the emerging fields owing to its potential of providing extensive bandwidth. Frequency Hopping (FH) has a high potential for use in wireless networks due to its key advantages of spreading the interference over wide bandwidth and of prov...
Conference Paper
Full-text available
Achieving significant performance gains both in terms of system throughput and massive connectivity, non-orthogonal multiple access (NOMA) has been considered as very promising candidate for the future wireless communications technologies. It has already received serious consideration for implementation in the fifth generation (5G) and beyond wirel...
Preprint
Full-text available
The problem of underwater acoustic (UWA) channel estimation is the non-uniform sparse representation that may increase the algorithm complexity and the required time. A mathematical framework utilizing l21 constraint with two-dimensional frequency domain is employed to enhance the channel estimation. The frame work depends on both main and auxiliar...
Conference Paper
Full-text available
Ultra-wideband (UWB) technology is being extensively used for indoor localization problems because of its ability to provide high accuracy, high data rate and low transceiver power for short range communications. There are several integrated circuits developed to apply this technology. However, the range for localization provided by these modules h...
Preprint
Full-text available
Achieving significant performance gains both in terms of system throughput and massive connectivity, non-orthogonal multiple access (NOMA) has been considered as a very promising candidate for future wireless communications technologies. It has already received serious consideration for implementation in the fifth generation (5G) and beyond wireles...
Preprint
Full-text available
With the rapid development of the Internet of Things (IoT), Indoor Positioning System (IPS) has attracted significant interest in academic research. Ultra-Wideband (UWB) is an emerging technology that can be employed for IPS as it offers centimetre-level accuracy. However, the UWB system still faces several technical challenges in practice, one of...
Preprint
Full-text available
This paper proposes low complexity detection for internet of underwater things (IoUT)s communication. The signal is transmitted from the source to the destination using several sensors. To simplify the computational operations at the transmitter and the sensory nodes, a single carrier frequency domain equalizer (SC-FDE) is proposed and amplify-and-...
Article
Full-text available
In this paper, an analytical framework is presented for device detection in an impulse radio (IR) ultra-wide bandwidth (UWB) system and its performance analysis is carried out. The Neyman–Pearson (NP) criteria is employed for this device-free detection. Different from the frequency-based approaches, the proposed detection method utilizes time domai...
Article
Full-text available
In the beyond 5G networks, extraordinary demands for data rates and capacity are to be met. A possible candidate to address these challenges is Non-Orthogonal Multiple Access (NOMA) technique, which leads to higher diversity gains and massive connectivity. One caveat of NOMA is the increased receiver complexity to nullify the Inter User Interferenc...
Article
Full-text available
In the next generation of mobile communication networks, unprecedented challenges are required to be met, such as much higher data rates and spectrum efficiency, lower latency, and massive connectivity. Non-orthogonal multiple access (NOMA) has recently been proposed as a promising technology to achieve much superior spectral efficiency compared to...
Conference Paper
In this paper, we analyze the performance of the proposed double threshold-based multi-relay selection for cooperative device-to-device (D2D) communication networks using differential modulation with distance constraints. The mathematical model of the proposed scheme is discussed and the proposed double-threshold based relay selection scheme consis...
Article
Full-text available
The Department of Transport in the United Kingdom recorded 25,080 motor vehicle fatalities in 2019. This situation stresses the need for an intelligent transport system (ITS) that improves road safety and security by avoiding human errors with the use of autonomous vehicles (AVs). Therefore, this survey discusses the current development of two main...
Preprint
In this letter, a new power allocation scheme is proposed to improve the reliability of cooperative non-orthogonal multiple access (CO-NOMA). The strong user is allocated the maximum power, whereas the weak user is allocated the minimum power. This power allocation alters the decoding sequence along with the signal-to-interference plus noise ratio...
Conference Paper
Full-text available
Non-orthogonal Multiple Access (NOMA) has gar-nered considerable attention as a prime candidate for the next generation of wireless communication systems due to its improvement of spectral efficiency. The proposed model exploits one of NOMA's key features, namely of users having to decode other users messages before decoding their own as part of Su...
Article
Hybrid digital to analog (D-A) precoding is widely used in millimeter wave systems to reduce the power consumption and implementation complexity incurred by the number of radio frequency (RF) chains that consume a lot of the transmitted power in this system. In this paper, an optimal number of RF chains is proposed to achieve the desired energy eff...
Conference Paper
Full-text available
Today's wireless communication networks transmit their signals based on the Orthogonal Multiple Access (OMA) principle. As the number of users increases, OMA based approaches may fail to meet the stringent requirements emerging in the 5th Generation of wireless communications for very high spectral efficiency and massive connectivity. Non-Orthogona...
Conference Paper
Hybrid digital to analog precoding is widely used in millimeter wave system to reduce power consumption. The radio frequency (RF) chains consume maximum transmitted power, therefore, in this paper optimal number of RF chains are selected to achieve the desired energy efficiency (EE). The novelty of the proposed method is in two folds. First, the op...
Conference Paper
Full-text available
Log-periodic antenna is a special antenna type utilized with great success in many broadband applications due to its ability to achieve nearly constant gain over a wide frequency range. Such antennas are extensively used in electromagnetic compatibility measurements, spectrum monitoring and TV reception. In this study, a log-periodic dipole array i...
Conference Paper
Supporting high user density and improving millimeter-wave (mm-Wave) spectral-efficiency (SE) is imperative in 5G systems. Current hybrid digital-to-analog beamforming (D-A BF) base stations (BS) can only support a particular user per radio frequency (RF) chain, which severely restricts mm-Wave SE. In this paper a novel low-complexity selection com...
Article
Full-text available
Device-to-device (D2D) assisted offloading heavily depends on the participation of human users. The content preference and sharing willingness of human users are two crucial factors in the D2D assisted offloading. In this paper, with consideration of these two factors, the optimal content pushing strategy is investigated by formulating an optimizat...
Article
Multivariate generalized Gaussian density (MGGD) is used to approximate the multiple access interference (MAI) and additive white Gaussian noise in pulse-based ultrawide bandwidth (UWB) system. The MGGD probability density function (pdf) is shown to be a better approximation of a UWB system as compared to multivariate Gaussian, multivariate Laplaci...
Article
In this letter, a joint detector for cooperative communication networks is proposed when the destination has limited hardware processing capability. The transmitter sends its symbols with the help of $L$ relays. As the destination has limited hardware, only $U$ out of $L$ signals are processed and the energy of the remaining relays is lost. To solv...
Article
Full-text available
In this paper, a new detector is proposed for an amplify-and-forward (AF) relaying system. The detector is designed to minimize the symbol-error-rate (SER) of the system. The SER surface is non-linear and may have multiple minimas, therefore, designing an SER detector for cooperative communications becomes an optimization problem. Evolutionary base...
Article
Efficient receiver designs for cooperative communication systems are becoming increasingly important. In previous work, cooperative networks communicated with the use of $L$ relays. As the receiver is constrained, it can only process $U$ out of $L$ relays. Channel shortening and reduced-rank techniques were employed to design the preprocessing matr...
Article
Full-text available
The ever growing demand of higher data rates can now be addressed by exploiting cooperative diversity. This form of diversity has become a fundamental technique for achieving spatial diversity by exploiting the presence of idle users in the network. This has led to new challenges in terms of designing new protocols and detectors for cooperative com...
Article
Full-text available
This paper investigates and compares the performance of wireless sensor networks where sensors operate on the principles of cooperative communications. We consider a scenario where the source transmits signals to the destination with the help of $L$ sensors. As the destination has the capacity of processing only $U$ out of these $L$ signals, the st...
Article
Full-text available
This paper investigates and compares the performance of wireless sensor networks where sensors operate on the principles of cooperative communications. We consider a scenario where the source transmits signals to the destination with the help of $L$ sensors. As the destination has the capacity of processing only $U$ out of these $L$ signals, the st...
Conference Paper
Full-text available
In this paper, we propose optimal linear detectors for non-orthogonal amplify-and-forward cooperative protocol when considering a single-relay scenario. Two types of detectors are proposed based on the principles of minimum mean square error (MMSE) and minimum bit error rate (MBER). The MMSE detector minimizes the mean square error, while the MBER...
Article
In this letter, a new detector is proposed for amplifyand- forward (AF) relaying system when communicating with the assistance of relays. The major goal of this detector is to improve the bit error rate (BER) performance of the receiver. The probability density function is estimated with the help of kernel density technique. A generalized Gaussian...
Conference Paper
This paper investigates and compares the performance of wireless sensor networks (WSN) when sensors operate on the principles of cooperative communications. We consider a scenario where the source transmits signals to the destination with the help of L sensors. As the destination has the capacity of processing only U out of these L signals, U stron...
Conference Paper
In this paper, a new detector is being proposed for amplify-and-forward (AF) relaying system when communicating with the assistance of L number of relays. The major goal of this detector is to improve the bit error rate (BER) performance of the system. The complexity of the system is further reduced by implementing this detector adaptively. The pro...
Article
Full-text available
Design of high-efficiency low-complexity detection schemes for ultrawide bandwidth (UWB) systems is highly challenging. This contribution proposes a reduced-rank adaptive multiuser detection (MUD) scheme operated in least bit-errorrate (LBER) principles for the hybrid direct-sequence timehopping UWB (DS-TH UWB) systems. The principal component anal...
Article
In this paper a range of reduced-rank adaptive multiuser detectors (MUDs) are proposed and investigated for the hybrid direct-sequence time-hopping ultrawide bandwidth (DS-TH UWB) systems. The adaptive MUDs are operated based on the recursive least square (RLS) principles. Three types of reduced-rank techniques are investigated, which are the princ...
Conference Paper
Full-text available
In this paper we consider the low-complexity detection in hybrid direct-sequence time-hopping ultrawide bandwidth (DS-TH UWB) systems. A reduced-rank adaptive LBER detector is proposed, which is operated in the least bit error-rate (LBER) principles within a detection subspace obtained with the aid of the principal component analysis (PCA)- assiste...
Thesis
The main motivation of this thesis is to design low-complexity high-efficiency pulse-based ultrawide bandwidth (UWB) systems with reasonable bit-error-rate (BER) performance. The thesis starts with proposing a new pulse-based UWB system, namely the hybrid direct-sequence time-hopping (DS-TH) UWB system. This novel pulse-based UWB system is capable...
Conference Paper
Full-text available
In this contribution reduced-rank adaptive minimum mean- square error multiuser detector (MMSE-MUD) is proposed and investigated for the hybrid direct-sequence time-hopping ultrawide bandwidth (DS-TH UWB) systems. The adaptive MMSE-MUD is operated based on the normalised least mean-square (NLMS) principles associated with using Taylor polynomial ap...
Conference Paper
Full-text available
This paper presents a novel ultrawideband (UWB), direct sequence code division multiple access (DS-CDMA) aided system designed for the IEEE 802.15.3a UWB channel specifications. Substantial performance improvements can be attained by serially concatenated channel encoding combined with a unity rate code (URC). We compare the performance of the iter...
Conference Paper
In this contribution decision-directed adaptive detection scheme based on normalised least mean-square (DD/NLMS) principles is proposed and investigated for the hybrid direct- sequence time-hopping ultrawide bandwidth (DS-TH UWB) system. The bit-error-rate (BER) performance of the hybrid DS-TH UWB system is investigated when communicating over the...
Conference Paper
This paper investigates and compares the performance of hybrid direct-sequence time-hopping (DS-TH) ultrawide bandwidth (UWB) systems using full-rank and various reduced-rank detections when minimum mean-square error (MMSE) principles are applied, while communicating over Nakagami-m fading channels. In addition to the full- rank MMSE detection, thr...
Conference Paper
Full-text available
In this contribution an adaptive detection scheme based on least mean square (LMS) principles is proposed and investigated in the context of the hybrid direct-sequence time-hopping ultrawide bandwidth (DS-TH UWB) systems. The bit-error-rate (BER) performance of the hybrid DS-TH UWB system is investigated when communicating over the UWB channels mod...
Conference Paper
Full-text available
This paper presents a novel analysis on the decoding convergence of Time Hopping (TH) and Direct Sequence (DS) Code-Division Multiple-Access (CDMA) Ultrawide Bandwidth (UWB) systems when communicating over multipath Nakagami channels. The analysis is based on the Extrinsic Information Transfer (EXIT) chart where the UWB systems are serially concate...
Conference Paper
Full-text available
This paper investigates and compares the performance of various ultrawide bandwidth (UWB) systems when communicating over Nakagami-m fading channels. Specifically, the direct-sequence (DS), time-hopping (TH) and hybrid direct-sequence time-hopping (DS-TH) UWB systems are considered. The performance of these UWB systems is studied, when using the co...
Article
Full-text available
As in the present scenario, the progression technology is looming towards the challenges of the present and revolutionary requirements; the interest in faster frequency hopping rates to scrutinize the performance of channel in the presence of AWGN has been heightened. The focus of formulation of this manuscript is the analytical behavior of fast fr...

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