Hakan Ali Cirpan

Hakan Ali Cirpan
Istanbul Technical University · Department of Electronics and Communication Engineering

PhD

About

200
Publications
26,802
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1,333
Citations

Publications

Publications (200)
Article
Full-text available
In cognitive radio (CR) systems, efficient spectrum utilization depends on the ability to predict spectrum opportunities. Traditional statistical methods for spectrum occupancy prediction (SOP) are insufficient for addressing the non-stationary nature of spectrum occupancy, especially with UEs’ increased mobility and diversity in the sixth-generati...
Article
Full-text available
As the number of services and applications with diverse requirements keeps increasing, it is therefore of paramount importance to develop more efficient resource allocation techniques. In this paper, we propose a pre-emptive scheduling mechanism for managing network slices, specifically enhanced Mobile Broadband (eMBB) and Ultra-Reliable Low-Latenc...
Article
Full-text available
Air dominance plays a crucial role in today’s battlefield, and its importance has increased over time with the development of advanced platforms and commercial technologies that enable the proliferation of air threats. The importance of ground based air defense systems, which protect air space and critical infrastructure, is also increasing in line...
Article
Full-text available
The authors analyse the sequential lobing radar (SLR) resistance against the scan rate modulation (SRM) jamming technique. Unlike previous studies, the authors analyse SLRs with sinc antenna patterns, enabling investigation of the sidelobe region's vulnerability. By incorporating second‐order angular tracking loops (SOATLs), the first analysis of b...
Conference Paper
Integrated Sensing and Communication (ISAC) is identified as a critical candidate technology for both 5G-Advanced and 6G networks. In this study, the baseband reference signal, which is highly valuable for sensing, is modified with a Power Amplifier (PA) with a known model. Thus, the proposed baseband reference signal strives to approximate the bas...
Article
Full-text available
As the complexity of wireless mobile networks increases significantly, artificial intelligence (AI) and machine learning (ML) have become key enablers for radio resource management and orchestration. In this paper, we propose a multi-agent reinforcement learning (RL) method for allocating radio resources to mobile users under random traffic arrival...
Article
Full-text available
Beyond fifth-generation (5G) wireless communication, reconfigurable intelligent surfaces (RIS) have emerged as a transformative technology that can redefine how we interact with and harness electromagnetic waves. Advancements in meta-materials and metasurfaces have brought about exceptional flexibility in controlling electromagnetic waves at scales...
Article
We address the challenge of source localization utilizing solely the changing rate of phase difference (CRPD) measurements from a mobile platform with a long baseline interferometer (LBI). The task of source localization with CRPD measurements presents a non-convex problem that demands sophisticated methodologies. In our study, we initially formula...
Article
Full-text available
Next-generation communication systems are expected to integrate artificial intelligence (AI) techniques into multi-antenna setups to improve system performance. One of the most important use cases of AI in wireless communications is multiple-input multiple-output (MIMO) systems, due to the superior AI capability of learning the best possible decisi...
Preprint
Full-text available
Perfect synchronization in LoRa communications between Low Earth Orbit (LEO) satellites and ground base stations is still challenging, despite the potential use of atomic clocks in LEO satellites, which offer high precision. Even by incorporating atomic clocks in LEO satellites, their inherent precision can be leveraged to enhance the overall synch...
Preprint
Full-text available
This paper presents field measurement-based channel characterization for air--to--ground (A2G) and air--to--air (A2A) wireless communication systems using two drones equipped with lightweight software-defined radios. A correlation-based channel sounder is employed such that the transmitting drone broadcasts the sounding waveform with a pseudo-noise...
Article
Offloading computationally heavy tasks from an unmanned aerial vehicle (UAV) to a remote server helps improve the battery life and can help reduce resource requirements. Deep learning based state-of-the-art computer vision tasks, such as object segmentation and object detection, are computationally heavy algorithms, requiring large memory and compu...
Article
This paper proposes a novel time-frequency warped waveform for short symbols, massive machine-type communication (mMTC), and internet of things (IoT) applications. The waveform is composed of asymmetric raised cosine (RC) pulses to increase the signal containment in time and frequency domains. The waveform has low power tails in the time domain, he...
Preprint
Full-text available
This paper proposes a novel time-frequency warped waveform for short symbols, massive machine-type communication (mMTC), and internet of things (IoT) applications. The waveform is composed of asymmetric raised cosine (RC) pulses to increase the signal containment in time and frequency domains. The waveform has low power tails in the time domain, he...
Article
Threat evaluation is a vital process in air and missile defense systems. The reliable output of threat evaluation is essential in order to use sensor and weapon resources efficiently. Fuzzy rule-based system has been proven to be effective and widely used in threat evaluation decision support systems in air defense applications since it can model e...
Preprint
Full-text available
Offloading computationally heavy tasks from an unmanned aerial vehicle (UAV) to a remote server helps improve the battery life and can help reduce resource requirements. Deep learning based state-of-the-art computer vision tasks, such as object segmentation and object detection, are computationally heavy algorithms, requiring large memory and compu...
Article
Full-text available
Reconfigurable intelligent surface (RIS)-aided communication has been regarded as one of the promising technologies for future wireless networks with regards to controlling the propagation environment and enhancing the quality of the end-to-end communication links. In this study, considering the importance of index modulation (IM) and RIS-aided sch...
Article
In literature, the scan rate modulation (SRM) jamming technique is only analyzed interpretively and qualitatively, which may lead suboptimal performance for sequential lobing radars (SLRs). Hence, this article focuses on the theoretical analysis and optimization of the SRM technique against SLRs. We theoretically analyze the SRM, provide quantitati...
Article
Full-text available
Modern air defense systems utilize active electronically scanned array multi-function phased array fire control radars, which provide multiple radar functions simultaneously with the help of a radar resource manager. As air defense systems become network-centric, those connected systems benefit from sharing radar resources to improve system effecti...
Article
Full-text available
Traditional deinterleaving algorithms first cluster the pulses in frequency, pulse width, and angle of arrival parameter space. Then, they utilize time of arrival analysis techniques. This results in a performance loss, since these processes are not jointly combined; rather, they are sequentially connected. Additionally, they perform poorly in the...
Preprint
Full-text available
Non-terrestrial networks (NTNs) are a critical enabler of the persistent connectivity vision of sixth-generation networks, as they can service areas where terrestrial infrastructure falls short. However, the integration of these networks with the terrestrial network is laden with obstacles. The dynamic nature of NTN communication scenarios and nume...
Preprint
High-quality radio frequency (RF) components are imperative for efficient wireless communication. However, these components can degrade over time and need to be identified so that either they can be replaced or their effects can be compensated. The identification of these components can be done through observation and analysis of constellation diag...
Article
Full-text available
This paper introduces the concept of spatial and media‐based modulated (SMBM) orthogonal frequency division multiplexing (OFDM) as a potential candidate for highly mobile next generation beyond 5G (B5G) wireless communications. The proposed SMBM‐OFDM technique utilizes not only the transmit antenna and channel state indices but also OFDM subcarrier...
Article
Full-text available
Air Defence System (ADS) effectiveness relies not only on weapon and sensor performances but also on effective usage of those resources. In an ADS Network, several ADS are deployed in an overlapping coverage in order to increase the protection of defended assets (DA). Limited tracking capacity of ADS fire control radars leads to a limited engagemen...
Preprint
Full-text available
In this paper, deep learning (DL)-aided data detection of spatial multiplexing (SMX) multiple-input multiple-output (MIMO) transmission with index modulation (IM) (Deep-SMX-IM) has been proposed. Deep-SMX-IM has been constructed by combining a zero-forcing (ZF) detector and DL technique. The proposed method uses the significant advantages of DL tec...
Preprint
Full-text available
In this paper, a deep convolutional neural network-based symbol detection and demodulation is proposed for generalized frequency division multiplexing with index modulation (GFDM-IM) scheme in order to improve the error performance of the system. The proposed method first pre-processes the received signal by using a zero-forcing (ZF) detector and t...
Article
Full-text available
Passive systems, such as Electronic Intelligence (ELINT) and Electronic Support Measures (ESM) systems, aim to extract necessary information from the received radar signals for situational awareness. To achieve that, the system must first deinterleave the radar signals simultaneously coming from different emitters so that the pulse repetition inter...
Article
Full-text available
Safety, security, and privacy are three critical concerns affiliated with the use of drones in everyday life. Considering their ever-shrinking sizes and capabilities, being aware of drone activities in the vicinity becomes an important surveillance item. Therefore, keeping track of drones and preferably their controllers should be included into the...
Article
Any operation scenario for unmanned aerial vehicles also known as drones in real world requires resilient wireless link to guarantee capacity and performance for users, which can only be achieved by obtaining detailed knowledge about the propagation channel. Thus, this study investigates the large-scale channel propagation statistics for the line o...
Conference Paper
Full-text available
This paper investigates the performance of channel estimation models with an assumed fixed error with respect to the reference signal-aided channel estimation in the matter of spatial media-based modulation (SMBM) systems. For both cases, SMBM system performance is presented by average bit error rate simulations and the closed-form expressions of e...
Article
Full-text available
In this work, we propose the reference signal-aided channel estimation approach which is a crucial requirement to address the realistic performance of spatial media-based modulation (SMBM) systems where the digitally controllable radio frequency mirrors are deployed on the multiple transmit antennas. Accordingly, least squares and linear minimum me...
Chapter
In this paper, deep learning (DL)-aided data detection of spatial multiplexing (SMX) multiple-input multiple-output (MIMO) transmission with index modulation (IM) (Deep-SMX-IM) has been proposed. Deep-SMX-IM has been constructed by combining a zero-forcing (ZF) detector and DL technique. The proposed method uses the significant advantages of DL tec...
Article
In this paper, we present an analytical model to characterize the average queuing delay for non-orthogonal multiple access (NOMA) downlink system by taking the outage event into account such that the user fails either decoding its own signal or performing SIC for the signals of other users at the receiver when the SINR is lower than a predefined ou...
Article
In this work, we propose a novel method utilizing iterative semidefinite relaxation for geolocation of stationary uncooperative radars. In our scenario, the geolocation is to be performed in a receiver located on a moving platform. The proposed method uses frequency measurements that are Dopplershifted due to the platform motion. First, constructed...
Conference Paper
Full-text available
In this paper, deep learning (DL)-aided data detection of spatial multiplexing (SMX) multiple-input multiple-output (MIMO) transmission with index modulation (IM) (Deep-SMX-IM) has been proposed. Deep-SMX-IM has been constructed by combining a zero-forcing (ZF) detector and DL technique. The proposed method uses the significant advantages of DL tec...
Preprint
Full-text available
In this letter, we study the reference signal-aided channel estimation concept which is a crucial requirement to address the realistic performance of spatial media-based modulation (SMBM) systems where the radio frequency mirrors are deployed along with the multiple transmit antennas. Accordingly, least squares and linear minimum mean square error-...
Preprint
Full-text available
In this paper, a deep learning based receiver is proposed for a collection of multi-carrier wave-forms including both current and next-generation wireless communication systems. In particular, we propose to use a convolutional neural network (CNN) for jointly detection and demodulation of the received signal at the receiver in wireless environments...
Preprint
Full-text available
The applications of the unmanned aerial vehicles (UAVs) increase rapidly in everyday life, thus detecting the UAVs and/or its pilot is a crucial task. Many UAVs adopt frequency hopping spread spectrum (FHSS) technology to efficiently and securely communicate with their radio controllers (RC) where the signal follows a hopping pattern to prevent har...
Preprint
Full-text available
Powered by the advances in microelectronics technologies, unmanned aerial vehicles (UAVs) provide a vast variety of services ranging from surveillance to delivery in both military and civilian domains. It is clear that a successful operation in those services relies heavily on wireless communication technologies. Even though wireless communication...
Conference Paper
Full-text available
In this paper, a deep convolutional neural network-based symbol detection and demodulation is proposed for generalized frequency division multiplexing with index modulation (GFDM-IM) scheme in order to improve the error performance of the system. The proposed method first pre-processes the received signal by using a zero-forcing (ZF) detector and t...
Conference Paper
Full-text available
In this paper, a deep neural network for Generalizedfrequency division multiplexing (GFDM) symbol detection anddemodulation is considered. A new receiver model, includingclassical linear detector based coarse detection and deep neuralnetwork-based fine detection, is proposed in order to improve theerror performance of the system. It has been demons...
Article
The demand for wireless access continues to grow with the new applications which create a broad range of technical challenges. Although orthogonal frequency division multiplexing (OFDM) with multiple numerologies concept will likely address the current technical challenges of fifth generation (5G) wireless networks, the sufficiency of OFDM-based ph...
Article
Full-text available
Nonorthogonal multiple access (NOMA) is one of the key technologies for 5G, where the system capacity can be increased by allowing simultaneous transmission of multiple users at the same radio resource. The most of the proportional fairness (PF)–based resource allocation studies for NOMA systems assumes full buffer traffic model, while the traffic...
Article
Full-text available
This paper explores the performance of time-domain synchronous orthogonal frequency division multiplexing (TDSOFDM) systems operated under rapidly time-varying mobile channels. Since a rapidly time-varying channel contains more unknown channel coefficients than the number of observations, the mobile channel can conveniently be modeled with the disc...
Article
In this letter, generalized frequency division multiplexing (GFDM) is combined with index modulation (IM) exploiting the block based structure of GFDM in an innovative way. The proposed GFDM-IM scheme uses flexible IM numerology to reduce out-of-band (OOB) emission and provides a novel multi-layer system model to further benefit from the enhanced d...
Conference Paper
Full-text available
This paper analyzes the effects of channel estimation errors on the error performance of the recently proposed quadrature channel modulation (QCM) over flat Rayleigh fading channels. A closed-form expression for the pairwise error probability (PEP) of the QCM scheme is derived in the presence of channel estimation errors, and used to calculate uppe...
Presentation
Full-text available
SpatialModulationGFDM: A LowComplexityMIMO-GFDM System for 5G Wireless Communication
Article
Full-text available
After the vision and the overall objectives of future wireless networks for 2020 and beyond have been defined, standardization activities for fifth generation (5G) wireless networks have been started. Although it is expected that 5G new radio (NR) will be based on cyclicly prefixed orthogonal frequency division multiplexing (CP-OFDM)-based waveform...
Conference Paper
Full-text available
This paper presents an extended joint resource optimization framework for multi-service transmissions in high-speed railway (HSR) wireless networks by introducing the average delay constraint into the dynamic resource management problem. The system utility is maximized under the constraints of average delay, queue stability and average power by for...
Conference Paper
Full-text available
Non-orthogonal multiple access (NOMA) is one of the key technologies for 5G, where the system capacity can be increased by allowing simultaneous transmission of multiple users at the same radio resource. In this paper, we propose a genetic algorithm (GA) based multiuser radio resource allocation scheme for NOMA downlink systems. In our setup , GA i...
Conference Paper
Full-text available
Generalized frequency division multiplexing (GFDM) has been regarded as one of the promising candidates for the physical layer (PHY) of fifth generation (5G) wireless networks. Multiple-input multiple-output (MIMO) friendliness is a key ability for a physical layer scheme to match the foreseen requirements of 5G wireless networks. On the other hand...