This letter studies the performance of the line-ofsight underground mine channel in the millimeter wave band. Using a vector network analyzer (VNA) and three carefully chosen antennas, one omni and two horn antennas, we performed... more
This paper investigated frequency sharing between primary TV systems (channels 32 and 49) and Emergency Communication Networks (ECNs). The networks to be implemented in the Osogbo axis of Osun State function on a secondary geographical... more
A 0.18μm CMOS MICS-band transceiver with a reconfigurable RF front-end is presented, reusing the same circuit core for super-regenerative wake-up receiver, receivemode LNA, and transmit power amplifier, eliminating the need for an... more
This letter presents a W-band high-power direct-conversion transmitter using digital predistortion techniques for digital modulation applications. The transmitter is a direct-conversion configuration that employs a reflection-type IQ... more
This paper presents the analysis and simulation of a high efficiency transmitter combining a polar sigma-delta modulator and a high efficiency amplifier. This study is carried out considering high PAPR (Peak to Average Power Ratio) mobile... more
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or... more
We report on our investigation into radio communications problems faced by emergency responders in disaster situations. A fundamental challenge to communications into and out of large buildings is the strong attenuation of radio signals... more
We develop and characterize an inexpensive, reliable system for use in weak-signal detection. The system is implemented using widely available components, including a communications receiver and a computer sound card. Our characterization... more
I am also grateful to my family, who has always been there to support me. In particular, I would like to mention my elder brother Adnan, with whom I always had absorbing exchange of arguments on different topics which many times used to... more
This letter studies the rate-equivocation region of a degraded signal-dependent noise wiretap channel (SDGN-WC), where the noise is Gaussian. This signal-dependent noise occurs in optical wireless communication (OWC) settings based on... more
In a high density wireless environment, channel interference among users of many overlapped Basic Service Sets (OBSSs) is a serious problem. Our solution for the problem relies on a resource coordination scheme that utilizes the spatial... more
Problemas Física, libro Tipler, Capítulo Moléculas y sólidos.
Spectrum sensing is essential in cognitive radio to enable dynamic spectrum access. In many scenarios, primary user signal must be detected reliably in low signal-to-noise ratio (SNR) regime under required sensing time. We propose to use... more
317-321Field strength data have been collected during the year 1973-74 in the service areas of the TV transmitters operating at Bombay, Poona and Srinagar , Data for about 29 path profiles in these areas have been analyzed to study the... more
A thesis submitted to McGill University in partial fulfillment of the requirements of the degree of Master of Engineering.
In this paper we consider the uplink transmission in MC-CDMA (MultiCarrier -Coded Division Multiple Access) systems. Since MC-CDMA signals are OFDM-like multicarrier signals, they have high envelope fluctuations and a high PMEPR... more
From a conceptual perspective, 5G technology promises to deliver low latency, high data rate and more reliable connections for the next generations of communication systems. To face these demands, modulation schemes based on Orthogonal... more
A MIMO-OFDM wireless communication technique possesses several advantages accrued from combining MIMO and OFDM techniques such as increased channel capacity and improved BER performance. This has made the technique very amiable to current... more
Centralized control and coordination of the connections in a wireless network is not possible in practice. To keep the delay from measurement instants to actuating the decisions, distributed control is required. This paper focuses on the... more
We present a practical and provably-secure multinode communication scheme in the presence of a passive eavesdropper. The scheme is based on a random scheduling approach that hides the identity of the transmitter from the eavesdropper.... more
Cognitive Radio (CR) is considered as one of the prominent techniques to improve the spectrum utilization by opportunistically sharing the radio spectrum resources with licensed users. This paper concentrates on characterizing the... more
Cooperation between the primary and secondary systems can improve the spectrum efficiency in cognitive radio networks. The key idea is that the secondary system helps to boost the primary system's performance by relaying and in return the... more
We consider a signaling format where the information to be communicated from one or multiple transmitters to a receiver is modulated via a superposition of independent data streams. Each data stream is formed by error-correction encoding,... more
In this correspondence, we study the convexity properties for the problem of detecting the presence of a signal emitted from a power constrained transmitter in the presence of additive Gaussian noise under the Neyman-Pearson (NP)... more
In this article, a new TDMA based wireless sensor network (WSN), MILMON, is proposed for military monitoring. The most important design considerations of MILMON are energy consumption, delay, scalability, and fault tolerance. There are... more
In this paper, an Adaptive Code NonUniform Modulation with Orthogonal Frequency Division Multiplexing (OFDM) System was evaluated in the underwater acoustic communication channel. This system was adopted from the Subcarrier arrangement of... more
For a single user Gaussian channel, the minimum power required to meet a specified BER at the receiver is wellknown. For multiple transmitters sending independent data to a single receiver (which uses separate linear filters for decoding... more
A model for the mobile radio channel is proposed that is intended to apply to wideband signals in the 900 MHz band. The model is specified by a two-variable impulse response h,(t), where x represents the location of the receiver. The... more
For the characterization of TV White Spaces (TVWS), an extensive simulation of the impact of interfering signals was undertaken in a generalized scenario. The simulation for these investigations was derived from a Monte Carlo methodology... more
In this paper we develop a framework for optimizing the performance of the secondary link in terms of the average spectral efficiency assuming quantized channel state information (CSI) of the secondary and the secondary-to-primary... more
This is the second paper in a series of using cognitive radio network as wireless sensor network. The motivation of the paper is to push the convergence of radar and communication systems into a unified cognitive network. This paper... more
We study the two-user MIMO block fading twoway relay channel in the non-coherent setting, where neither the terminals nor the relay have transmit or receive knowledge of the channel realizations. We present a lower bound on the achievable... more
In context of the oscillation-based-test (OBT) technique, a simple and low-cost method of testing oscillators by comparison of finite segment of waveform with the ideal sine-wave is presented. The method is based on the subtraction of two... more
Opportunistic radio spectrum access has the possibility to improve spectrum utilization needed for next generation mobile networks. The main challenge to opportunistic radio spectrum access lies in finding balance in conflicting goals of... more
The fingerprint and localization of radio signals employing a multichannel photonic analog-to-digital converter (ADC) is proposed, analyzed and demonstrated in a laboratory experiment. The photonic-ADC detects the radio signals with high... more
This letter presents a W-band high-power direct-conversion transmitter using digital predistortion techniques for digital modulation applications. The transmitter is a direct-conversion configuration that employs a reflection-type IQ... more
Introduction During the last years, the standard step-index polymer optical fibre (SI-POF) with 1-mm core diameter has established itself as the preferred transmission medium for short-range optical data communications in automotive... more
In many applications retransmission of lost packets are not permitted. In an OFDM system, due to channel fading, only a subset of carriers are usable for successful data transmission. If the channel state information is available at the... more
The coexistence of a single-input single-output (SISO) primary link and a multiple-input single-output (MISO) secondary link is considered in an extended cognitive radio channel setup, where the secondary transmitter has to obtain... more
In this paper, we study the effect of channel output feedback on the sum capacity in a two-user symmetric deterministic interference channel. We find that having a single feedback link from one of the receivers to its own transmitter... more
This letter presents a hardware-efficient technique to scale the power consumption of dynamic element matching (DEM) DACs with the static back-off level of the digital input signal. Unlike previous DEM techniques, the proposed... more
The paper highlights some of the newest results achieved in the framework of the Transmitter Modeling for wideband access transmitters work package within the IST-EU Network of Excellence TARGET. Two cases of study have been considered to... more
his article presents a generalized indoor-to-outdoor signal propagation model based on ray-tracing and exhaustive measurements campaign with the aim of developing a unified model for the interference in fifth-generation (5G) networks with... more
To implement a mobile radio system, wave propagation models are necessary to determine propagation characteristics for any arbitrary installation. The predictions are required for a proper coverage planning, the determination of multipath... more
Rolle's Theorem (RT) and Lagrange's Mean-value Theorem (LMVT) are significant for pure and applied mathematics, and they have applications in various other fields such as management, physics etc. RT is significant in finding the... more
This paper presents an optimal rate scheduling algorithm called Truncation for an energy-harvesting enabled wireless transmitter to transmit a set of dynamically arrived packets with minimum transmission energy. Distinct from existing... more