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In this paper, we investigate the channel correlation problem which affects the performance of indoor multiple-input multiple-output (MIMO) visible light communication (VLC) systems. More specifically, in order to reduce the high correlation of channel matrix in MIMO-VLC intensity channel, we propose a non-imaging receiver called angle-aided mirror diversity receiver (AMDR) which utilizes not only...
This paper investigates the impact of antenna correlation on wireless powered dual-hop multi-antenna relaying systems with instantaneous channel state information (CSI) or statistical CSI at the relay. Considering the power-splitting architecture, we study the outage probability as well as the achievable diversity order of the system for amplify-and-forward protocol. Our results show that, antenna...
L1-L2C is the first dual-frequency pair of civilian GPS signals, expected to become available over the full constellation by 2019. Pre-operational CNAV broadcast is made available to support development of L2C signal processing capability in modernized GPS receivers. The transmission of synchronized L1 C/A and L2C codes by Block IIR-M and follow-on generations of GPS satellites allows GPS receiver...
Since the near-far problem is expected to be a significant issue in the context of tactical communications, the tolerable amount of adjacent channel interference (ACI) is an important design requirement. We describe a numerical simulator which has been developed in order to evaluate the level of ACI arising in mobile ad hoc networks (MANET) in the VHF band when a large number of nodes and radio networks...
Spread spectrum communication systems can require significant computation to perform initial acquisition, searching across time and frequency to accurately detect and lock onto the desired signal. This initial acquisition problem is exacerbated in deeply spread non-binary signals lacking cyclostationary features or repetitive codes, leading to a desire for less computationally intensive approaches...
Information fusion is an important step in cooperative reconnaissance signal processing, which can be divided into three types: data-level, feature-level and decision-level fusion. Data-level fusion has the advantage of information completeness but the large data volume makes it hard to apply practically. Based on the sparse representation of intercepted signal and the correlations between signals,...
With the rapid development of software radio, the research and design of Global Navigation Satellite System(GNSS) software receiver has become a hot research topic in the whole satellite navigation system. In this paper, a new signal acquisition algorithm based on FFT parallel code phase search is proposed, which is based on the research of the base-band signal processing method in GNSS software receiver,...
In an uplink massive multiple-input-multiple-output (MIMO) deployment with distributed single-antenna users and a large base-station array, we investigate the performance of low complexity Vertical Bell Laboratories Layered Space Time (C-V-BLAST) and zero forcing (ZF) receivers. Unlike previous work which assumes that the channel is perfectly known, we focus on the realistic scenario where the MIMO...
This paper considers the problems of efficiency estimation of using different types of modulation of hydroacoustic signals of AUV communication, navigation and control systems. The types of signal were investigated: simple signal, linear frequency modulation signal and direct sequence spread spectrum. The signals were compared by the noise immunity, time resolution and detection probability with usage...
The research is devoted to the reduction of multiple access interference (MAI) in chaos-based asynchronous direct sequence code division multiple access (DS-CDMA) communication systems by use of spreading sequences which are selected from a large set of generated chaotic sequences. For the generation of binary chaotic spreading sequences different 1-dimensional maps are examined. As selection criteria...
This paper presents an active communication mechanism based on SNS user behavior (e.g., likes, shares, replies) in e-learning. For this, we propose a novel automatic link generation method by considering users' knowledge and interests during the conversation on SNS. The method generates two kinds of links to promote user communication in e-learning, 1) knowledge support for receivers who receive posts...
This paper evaluates the simultaneous impact of antenna correlation and imperfect channel state information (CSI) on the sum rate achievable in the compound multiple-input multiple-output (MIMO) Broadcast Channel (BC). The considered correlation model incorporates the correlation due to the proximity of antenna elements at both transmitter and receiver sides. We analyse the achievable sum rate and...
This paper studies the ergodic capacity of multiple-input multiple-output (MIMO) correlated Gamma-Gamma (G-G) fading channels, particularly for free-space optical communications (FSO). Based on the atmospheric fading correlation analysis and by employing an approximation method for the sum of correlated (G-G) random variables (RVs), closed-form expressions for the capacity are derived for both equal...
The paper introduces a novel method for distance estimation based on an OFDM signal combined with the Zadoff-Chu sequences. By exploiting the properties of these sequences, it is possible to evaluate the distance between two active nodes with a very good precision and accuracy. The technique effectiveness is demonstrated by measuring the distance between a single transmitter and a synchronized receiver...
Collective Detection (CD) is an interesting technique for acquiring highly attenuated satellites signals in harsh environment. The idea of this approach is to process all signals in view collectively to take advantage of the spatial correlation between GNSS signals as vector acquisition. In this way, the acquisition of weak signals will be facilitated by the presence of stronger ones. Increasing the...
This paper proposes a Doppler resilient modulation approach that can be used in acoustic local positioning systems with Binary Phase-Shift Keying (BPSK) modulated signals for Time-of-Flight (ToF) estimation. The proposed approach is implemented in the receiver and can be performed in parallel with other classic techniques to improve the position estimation process. The technique is based on Differential...
In this contribution, a cyclic-TDOA methodology is simulated. The simulation is a preliminary study that would allow to design and to implement an indoor optical-positioning system relaxing the synchronization requirements among receivers. The synchronism requirement relaxations are carried out by the modification of the structure of the positioning system considering an emitter beacon formed with...
Analogous to optical interferometry, scientists have developed seismic interferometry(SI) method, and its application in the field data have promoted the understanding and study of seismic wave propagation. Seismic interferometry can be applied to both controlled-source data and passive data. Under specific circumstances, the useful subsurface information can be retrieved with passive source seismic...
The paper is aimed at the determination and verification of system parameters, that can be achieved with the utilization of commonly available RTL-SDR software defined receiver in TDOA based system intended for position determination of the small-UAS. The paper describes a way of performing practical experiments, measurement setup and properties of the signal used. Experimental results lead to the...
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