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This article presents the analysis of the influence of environmental variables on the received signal power from a point to point wireless link (f = 5.52 GHz) in a tropical urban environment, in the cities of Guayaquil and Duran, of Ecuador. The study included data of five variables such as relative humidity (HR), atmospheric temperature (T), solar radiation (RS), rainfall (Pr) and signal power (P)...
Traditional cryptographic secret key establishment mechanisms are facing challenges with the fast growth of high-performance computing, and can be very costly in many settings, e.g. in wireless ad-hoc networks, since they consume scarce resources such as bandwidth and battery power. As an alternative, link-signature-based (LSB) secret key extraction techniques have received many interests in recent...
Cognitive radio (CR) is an intelligent system for designing modern wireless communication systems. Spectrum sensing is one of the most important issues in CR. This paper presents a semi blind spectrum sensing method which exploits the combination of comb filter and autocorrelator. The proposed method improves the detection performance of blind spectrum sensing in severe noise environments where an...
The article presents an analysis of correlation-based clustering procedure in cooperative spectrum sensing. The motivation is to assess if it is more beneficial in terms of energy efficiency to group nodes according to the received signal-to-noise ratio (SNR) on the link between Primary User and node or according to the distance between nodes. To this end, a merged clustering measure is introduced...
Due to dense small cells deployment in a heterogeneous network, the backhaul links among the small cells and macro cell are band-limited when they share the same spectrum with the user equipments. To mitigate the intra- and inter-cell interference caused by the band-limited backhaul, we propose a recursive estimation-based zero-forcing beamforming (RE-ZFBF) scheme. Based on initial values obtained...
In this paper, we describe a 920 MHz band long range wireless SAW passive tag system (WSPTS) for vibration monitoring, which achieves more than 10m reading distance. For the purpose of structural health monitoring (SHM) of aging infrastructures (e.g. bridge, building, and so forth), passive wireless sensor systems are an attractive option because they are operated battery-less and almost maintenance...
In this paper, we describe a 920 MHz band long range wireless SAW passive tag system (WSPTS) for vibration monitoring, which achieves more than 15 m reading distance. For the purpose of structural health monitoring (SHM) of aging infrastructures (e.g. bridge, building, and so forth), passive wireless sensor systems are an attractive option because they are operated battery-less and almost maintenance...
Based upon recent results from an air-ground channel measurement campaign, we investigate relationships between three common channel parameters: Ricean K-factor, stationarity distance (SD), and root-mean square delay spread (RMS-DS). Results show that SD and K are positively correlated, SD and dK/dt are negatively correlated, and SD and the temporal derivative of RMS-DS are also negatively correlated.
This paper designs and implements a Steady State Visually Evoked Potential (SSVEP) intelligent home service system based on Canonical Correlation Analysis (CCA), which realizes that electroencephalogram (EEG) controls home service. The system includes a stimulus module, a data acquisition module, a data analysis module and a controlled module. Experiments show that the correct accepting rate of instructions...
Latest developments in wireless communication networks push the limits of conventional security methods. Security can be improved with a secret key that is dynamically generated based on the surrounding physical environment. With this objective, physical layer security approaches can be implemented by means of simple signal processing methods. In this paper, we propose novel key extraction approaches...
Cognitive radio (CR) was proposed in wireless communications to improve spectral efficiency based on the concept of opportunistic spectrum access. Because orthogonal frequency division multiplexing (OFDM) has become the major access technique, an efficient spectrum sensing technique targeted at OFDM-based signals is one of the primary requirements of CR networks. To reduce computational complexity,...
Many wireless networks provide a large number of available channels for data transmissions. Due to the multi-path environment, channels have different channel qualities. There- fore, selecting a good channel from the multiple channels can improve the communication effectiveness. The Packet Reception Rate (PRR) has been utilized to represent the channel quality. In order to know which channel has good...
In wireless communication, heterogeneous technologies such as WiFi, ZigBee and BlueTooth operate in the same ISM band.With the exponential growth in the number of wireless devices, the ISM band becomes more and more crowded. These heterogeneous devices have to compete with each other to access spectrum resources, generating cross-technology interference (CTI). Since CTI may destroy wireless communication,...
This work proposes a novel authentication method for identifying Unmanned Aerial Vehicles (UAVs) based on a channel-tap power. A ground control station utilized the channel-tap power as a radio-frequency fingerprint (RFF) to directly detect UAVs via physical (PHY) layer. The proposed authentication method uses the Neyman-Pearson test to discriminate between two UAVs, UAVI and UAVA, which are controlled...
Coordinated multi-point transmission can provide high spectral efficiency for cellular systems. However, along with the increment in the amount of data, backhaul gradually becomes the bottleneck in terms of system performance and cost. In this paper, the backhaul delay is mainly focused in coordinated cellular networks and a hybrid channel prediction (HCP) algorithm is proposed. This algorithm combines...
The sum rate performance of distributed multiple-input multiple-output (D-MIMO) systems with Zero-Forcing (ZF) receivers over semi-correlated K fading channels involves special functions, which hinders us to further manipulations. To solve this issue, we derive the closed-form expressions of the achievable sum rate by using moment matching method, which is achieved by using a Gamma distribution to...
In this paper, we analyze uplink sum rate of multiple-input multiple-output (MIMO) systems with maximum-ratio combining (MRC) receivers. To be practical, receive correlation and different powers of users are assumed. Two novel approximate results on sum rate are derived in closed form. Based on the results, we also obtain the asymptotic results on sum rate when the number of base station antenna (M)...
Due to the unreliable nature of wireless links, sensor nodes frequently encounter degraded performance or lack of connection. This paper provides a real-time status monitoring and channel error diagnosis method in a wireless sensor network. It uses a poll and echo procedure to efficiently collect some physical layer and link layer statistics from both transmitter side and receiver side. A machine...
In Wireless Body Area Networks (WBANs), on-body channels undergo temporal variations predominantly because of the body motion and shadowing of tissue. This paper focuses on a common human activity, walking, to explore the characteristics of the dynamic on-body propagation channel. A customized portable wireless sounder is built and utilized to collect the original on-body channel data both for the...
In this paper, we investigate wireless information and power transfer in full-duplex (FD) two-way massive MIMO amplify-and-forward (AF) relaying network. In the considered network, the relay is an energy demander and applies time switching scheme to harvest energy from the users for amplifying and forwarding the users'' signals. Different from prior studies, MIMO users and antenna correlation are...
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