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Visible Light Communication (VLC) has become popular for its feasible and reliable speed and anti-jamming features. In fact, the structure of the transmission system for commercial usage has mainly limited the VLC transmission to downlink. To achieve higher transmission rate, a proper design of transmission constellation should be designed according to channel condition. In this work, we develop a...
This paper focuses on the achievable secrecy throughput in the hybrid automatic repeat request (HARQ) protocol over quasi-static Rayleigh fading channels for the wiretap channel model. We propose a scheme that ensures reliable and secure communication utilizing polar coding in conjunction with the HARQ protocol. Security and reliability is ensured even when the instantaneous power of the wiretap channel...
In this paper, we present an optical computing method for string data alignment applicable to genome information analysis. By applying moire technique to spatial encoding patterns of deoxyribonucleic acid (DNA) sequences, association information of the genome and the expressed phenotypes could more effectively be extracted. Such moire fringes reveal occurrence of matching, deletion and insertion between...
The focus of this work is on the design of Raptor codes for continuous variable Quantum key distribution (CV-QKD) systems. We design a highly efficient Raptor code for very low signal to noise ratios (SNRs), which enables CV-QKD systems to operate over long distances with a significantly higher secret key rate compared to conventional fixed rate codes. The degree distribution design of Raptor codes...
This paper considers the problem of energy efficient beamforming allocation in a cellular wireless network. Unlike most of the existing work that considers the problem at the physical layer, we include in our analysis the impact of the bursty traffic patterns of the users. We formulate a stochastic optimization problem that minimizes the average transmit power of the network such that the queues of...
Modern wireless communication systems adapt the employed Modulation and Coding Scheme (MCS) to the instantaneous channel quality in order to maximise the amount of bits correctly transmitted per time unit (i.e., the throughput). An important aspect in the study of this technique, referred to as Adaptive Modulation and Coding (AMC), is the characterisation of the link throughput performance under realistic...
In this paper, we consider an overlay cognitive radio network that transmits discrete-time analog sources over additive white Gaussian noise channels. Our focus is on the case where the primary and secondary sources are correlated. The secondary user (SU) knows the primary message non-causally, and allocates part of its power for transmitting the primary message. We study a hybrid digital-analog coding...
FSO systems are speedily attaining attractiveness for delivering various communication services and have become one of the preferred high-speed media. The primary challenge for FSO systems is atmospheric conditions that result in degradation of signal strength. In this paper, the impact of advance line-coding over FSO link subjected to different turbulent conditions has been investigated. The proposed...
Modern wireless systems deal with the adverse and unpredictable channel conditions using two main transmission schemes considered as complimentary: adaptive modulation and coding (AMC) and hybrid ARQ (HARQ). In this work we use the effective capacity as the performance measure to evaluate different design options. We thus show how to calculate this performance measure under independent, identically...
Cooperative communication uses spatial diversity to mitigate multipath fading. With an appropriate assignment of partners it also decreases the energy expenditure of the network. Together with optimum transmit power allocation, it is a useful technique to overcome the energy constraint problem in wireless sensor nodes. The calculation of optimum power in a Rician fading channel is a computationally...
This paper presents a low-complexity yet effective method for encoding High Dynamic Range data into two distinct Low Dynamic Range images to be subsequently lossy or losslessly compressed using any LDR image and video codec. The method and principles described herein are applicable to both still HDR images and sequences used for HDR-video creation. The peculiar features of the method allow LDR image...
We review coding techniques for fiber-optic distributed strain and temperature sensors, Brillouin Optical Time Domain Analysis (BOTDA) and Brillouin Optical Time Domain Reflectometry (BOTDR), based on stimulated and spontaneous Brillouin scatterings. The straightforward employment of previous coding techniques fails to enhance signal-to-noise ratio with high spatial resolution. The failure is caused...
Stochastic Computing (SC) is a fault tolerant design paradigm where numeric data are converted to probabilities on streams of random digital bits. This representation allows computing on low complexity hardware. SC allows a significant area reduction and an increased tolerance to transient errors, but presents high latency to achieve a moderate accuracy. Recent papers address this issue using parallelism...
The wireless communication system frequency diversity can be exploited with the help of Space frequency coding. In order to gain maximum frequency diversity various environment criteria needs to be considered. This paper proposes a practical approach of Distributed Space Frequency Coding [DSFC] for non-identically distributed [i.n.d] fading environment. As the geographical location of nodes is different,...
In this paper, we present a throughput optimized cross-layer design for multiple-input multiple-output (MIMO) wireless systems. The proposed design efficiently combines power control (PC), adaptive modulation and coding (AMC) and MIMO technology at the physical layer, with an automatic repeat request (ARQ) protocol at the data-link layer. Both basic ARQ and type-I hybrid ARQ are considered. More specifically,...
This paper presents an efficient DNN design with stochastic computing. Observing that directly adopting stochastic computing to DNN has some challenges including random error fluctuation, range limitation, and overhead in accumulation, we address these problems by removing near-zero weights, applying weight-scaling, and integrating the activation function with the accumulator. The approach allows...
This paper investigates the design of low-complexity error correction codes for the verification step in continuous variable quantum key distribution (CVQKD) systems. We design new coding schemes based on quasi-cyclic repeat-accumulate codes which demonstrate good performances for CVQKD reconciliation. Given quasi-cyclic repeat-accumulate codes' commercial maturity, low implementation complexity and...
We propose a coding scheme based on the combination of interleaving with systematic channel codes for secrecy. The basic idea consists of generating a random interleaving key that is used to shuffle/interleave information at the source. The message and the interleaving key are then both encoded with a systematic code and the part related to the interleaving key is removed/punctured before being sent...
In this paper, a novel hierarchical modulation symbol sharing scheme for multiuser cellular networks is proposed. In order to achieve the maximum channel capacity, various modulation and coding schemes have been developed on Wireless Communication Systems. With good modulation and coding schemes, very high channel capacity could be achieved for 1-to-1 communication systems. Due to different channel...
Recently researchers found that digital data can be encoded and decoded by different OAM modes. A novel digital data transmission method using orbital angular momentum (OAM) of electromagnetic (EM) fields is proposed in this paper. Firstly, we propose a tolerable encoding method using OAM mode, which is generated by the uniform circular array (UCA). Then, if the beam axis is known, a dual-polarized...
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