A5017283708- Advanced Wireless Communication Techniques
- Wireless Communication Networks Research
- Advanced Wireless Communication Technologies
- Optical Wireless Communication Technologies
- PAPR reduction in OFDM
- Cooperative Communication and Network Coding
- Advanced Photonic Communication Systems
- Blind Source Separation Techniques
- Indoor and Outdoor Localization Technologies
- Error Correcting Code Techniques
- Advanced Adaptive Filtering Techniques
- Advanced MIMO Systems Optimization
- Underwater Vehicles and Communication Systems
- Optical Network Technologies
- Semiconductor Lasers and Optical Devices
- Advanced Wireless Network Optimization
- Satellite Communication Systems
- Advancements in PLL and VCO Technologies
- Wireless Communication Security Techniques
- Image and Signal Denoising Methods
- Power Line Communications and Noise
- Direction-of-Arrival Estimation Techniques
- Digital Filter Design and Implementation
- Radar Systems and Signal Processing
- Analog and Mixed-Signal Circuit Design
Kadir Has University
2016-2025
Princeton University
2009-2021
Istanbul Technical University
1991-2016
Istanbul University
2002-2010
Bilkent University
2006
Işık University
1997-2005
New Jersey Institute of Technology
1992-2005
Texas A&M University
1999-2003
University Heights Center
1991
Marmara University
1984-1988
In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, called OFDM with index modulation (OFDM-IM), is proposed for operation over frequency-selective and rapidly time-varying fading channels. the information conveyed not only by M-ary signal constellations as in classical OFDM, but also indices of subcarriers, which are activated according to incoming bit stream. Different low complexity transceiver structures based on maximum likelihood detection or log-likelihood...
A novel multiple-input multiple-output (MIMO) transmission scheme, called space-time block coded spatial modulation (STBC-SM), is proposed. It combines (SM) and coding (STBC) to take advantage of the benefits both while avoiding their drawbacks. In STBC-SM transmitted information symbols are expanded not only space time domains but also (antenna) domain which corresponds on/off status transmit antennas available at domain, therefore core STBC antenna indices carry information. general...
This white paper explores the road to implementing broadband connectivity in future 6G wireless systems. Different categories of use cases are considered, from extreme capacity with peak data rates up 1 Tbps, raising typical by orders-of-magnitude, support at railway speeds 1000 km/h. To achieve these goals, not only terrestrial networks will be evolved but they also integrated satellite networks, all facilitating autonomous systems and various interconnected structures. We believe that...
This work investigates the negative effects of channel estimation errors on performance spatial modulation (SM) when operating over flat Rayleigh fading channels. The pairwise error probability SM scheme is derived in presence and an upper bound average bit evaluated for M-PSK M-QAM signalling. It shown via computer simulations that becomes very tight with increasing signal-to-noise ratio (SNR) quite robust to errors.
The IEEE has established the standardization group 802.15.7r1 “Short Range Optical Wireless Communications”, which is currently in process of developing a standard for visible light communication (VLC). As with any other system, realistic channel models are critical importance VLC system design, performance evaluation, and testing. This article presents reference that were endorsed by Task Group evaluation proposals. These developed typical indoor environments, including home, office,...
Visible light communications (VLC) is a promising and uncharted new technology for the next generation of wireless communication systems. This paper proposes novel generalized emitting diode (LED) index modulation method multiple-input-multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM)-based VLC The proposed scheme avoids typical spectrum efficiency losses incurred by time- frequency-domain shaping in OFDM signals. achieved exploiting spatial along with LED modulation....
In this letter, we propose a realistic channel model for visible light communication (VLC) assuming mobile user. Based on non-sequential ray tracing, first obtain impulse responses each point over the user movement trajectories, and then express path loss delay spread as function of distance through curve fitting. Our results demonstrate large variations in received power. system design, necessitates use adaptive schemes, where transmission parameters can be selected according to conditions....
This paper explores the road to vastly improving broadband connectivity in future 6G wireless systems. Different categories of use cases are considered, with peak data rates up 1 Tbps. Several enablers at infrastructure, spectrum, and protocol/algorithmic levels required realize intended goals 6G. At infrastructure level, we consider ultra-massive MIMO technology (possibly implemented using holographic radio), intelligent reflecting surfaces, user-centric cell-free networking, integrated...
The roles of trust, security and privacy are somewhat interconnected, but different facets next generation networks. challenges in creating a trustworthy 6G multidisciplinary spanning technology, regulation, techno-economics, politics ethics. This white paper addresses their fundamental research three key areas. Trust: Under the current "open internet" telco cloud can be used for trust services only equally all users. network must support embedded increased level information 6G. Trust...
The sixth generation (6G) of mobile network will be composed by different nodes, from macro-devices (satellite) to nano-devices (sensors inside the human body), providing a full connectivity fabric all around us. These heterogeneous nodes constitute an ultra dense managing tons information, often very sensitive. To trust services provided such network, security is mandatory feature design. In this scenario, physical-layer (PLS) can act as first line defense, even low-resourced in...
To cope with the explosive traffic growth expected in next-generation wireless networks, it is necessary to design multiple access techniques that can provide higher spectral efficiency as well larger-scale connectivity. As a promising candidate, power-domain non-orthogonal (NOMA) has been widely studied. In conventional NOMA, users are multiplexed same time and frequency band different <italic xmlns:mml="http://www.w3.org/1998/Math/MathML"...
6G networks have the burden to provide not only higher performance compared 5G, but also enable new service domains as well open door over a paradigm of mobile communication. This paper presents an overview on role and key challenges signal processing (SP) in future systems from conditioning at transmission MIMO precoding detection, channel coding estimation, multicarrier non-orthogonal multiple access (NOMA) optical wireless communications physical layer security (PLS). We describe core...
Spatial modulation (SM), in which multiple antennas are used to convey information besides the conventional M-ary signal constellations, is a new multiple-input multiple-output (MIMO) transmission technique, has recently been proposed as an alternative V-BLAST (vertical Bell Labs layered space-time). In this paper, novel MIMO scheme, called spatial with trellis coding (SM-TC), proposed. Similar coded (TCM), encoder and SM mapper jointly designed take advantage of benefits both. A soft...
This paper is concerned with the challenging and timely problem of joint channel estimation, equalization, data detection for uplink orthogonal frequency division multiplexing (OFDM) systems in presence selective very rapidly time varying channels. The resulting algorithm based on space alternating generalized expectation maximization (SAGE) technique which particularly well suited to multicarrier signal formats leading a receiver structure that also incorporates interchannel interference...
In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, which is called OFDM with index modulation (OFDM-IM), proposed for frequency-selective fading channels. inspiring from the recently introduced spatial concept multiple-input multiple-output (MIMO) channels, information conveyed not only by M-ary signal constellations as in classical OFDM, but also indices of subcarriers, are activated according to incoming bit stream. Different transceiver structures and...
In this paper, a new channel estimation algorithm is proposed that exploits sparsity in the time domain for an orthogonal frequency division multiplexing (OFDM)-based underwater acoustical (UWA) communications systems presence of Rician fading. A path-based model used, which described by limited number paths, each characterized delay, Doppler scale, and attenuation factor. The resulting initially estimates overall sparse tap delays shifts using compressed sensing approach, form matching...
Spatial modulation (SM) is a promising technique that reduces inter-channel interference while providing high power efficiency and detection simplicity. In order to ensure the secrecy of SM, precoding friendly jamming are widely adopted in literature. However, neither those methods can take advantage SM. this paper, novel spatial constellation design (SCD) proposed enhance physical layer security (PLS) optical generalized space shift keying (GSSK), which retain some benefits Due lack...
Ultra-dense HetNets (UDN)-based Millimeter-Wave (mmWave) massive MIMO is considered a promising technology for 5th generation (5G) wireless communications systems since it can offer massively available bandwidth and improve energy efficiency (EE) substantially. However, in UDN, the power consumption of system increases sharply with increase network density. In this paper, we investigate optimization EE mmWave UDN. To develop functions MIMO, first propose model where harvests electromagnetic...
We consider the physical layer security (PLS) of multi-user (MU) multiple-input-multiple-output visible light communication (VLC) systems with an eavesdropper (Eve) and propose a novel spatial constellation design technique based on generalized space shift keying (MU-GSSK-SCD). The received signals legitimate users are optimized jointly, such that their bit error ratios (BERs) minimized Eve's BER is significantly degraded. emission power randomly selected light-emitting diodes adjusted, by...
The non-terrestrial networks (NTNs) are recognized as a key component to provide cost-effective and high-capacity ubiquitous connectivity in the future wireless communications. In this paper, we investigate secure transmission terahertz (THz)-empowered reconfigurable intelligent surface (RIS)-assisted NTN (T-RANTN), which is composed of low-Earth orbit satellite transmitter, an RIS-installed high-altitude platform (HAP) two unmanned aerial vehicle (UAV) receivers, only one trustworthy. An...
This paper is concerned with a challenging problem of channel estimation and equalization for amplify-and-forward cooperative relay based orthogonal frequency division multiplexing (OFDM) systems in sparse underwater acoustic (UWA) channels. The sparseness the impulse response prior information non-Gaussian gains, modeled by an exact continuous Gaussian mixture (CGM), are exploited to improve performance algorithm. resulting novel algorithm initially estimates overall complex-valued taps...
In this paper, we propose optical orthogonal frequency division multiplexing with index modulation (O-OFDM-IM) for visible light communications (VLC) systems employing emitting diodes (LEDs) and photodetectors (PDs). The proposed scheme uses the indices of active subcarriers an OFDM system to transmit additional information bits. scheme, bipolar signals are asymmetrically clipped or DC biased a log-likelihood ratio (LLR) calculation based detector is used determine subcarriers. Our computer...
A visible light communication broadcast channel is considered, in which a transmitter luminaire communicates with two legitimate receivers the presence of an external eavesdropper. number trusted cooperative half-duplex relay luminaires are deployed to aid securing transmitted data. Transmitters equipped single fixtures, containing multiple emitting diodes, and receiving nodes photo-detectors, rendering considered setting as single-input single-output system. Transmission...
This paper is concerned with the challenging and timely problem of joint channel estimation equalization for orthogonal frequency division multiplexing (OFDM) systems in presence selective very rapidly time varying channels. The resulting algorithm based on space alternating generalized expectation maximization—maximum a posteriori probability (SAGE-MAP) technique which particularly well suited to multicarrier signal formats. implemented time-domain enables one use Gaussian approximation...