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Color brings extra data capacity for QR codes, but it also brings tremendous challenges to the decoding because of color interference and illumination variation, especially for high-density QR codes. In this paper, we put forth a framework for high-capacity QR codes, HiQ, which optimizes the decoding algorithm for high-density QR codes to achieve robust and fast decoding on mobile devices, and adopts...
We propose pairwise coding to enhance a superchannel's tolerance to non-idea ROADM filtering effect. Experimental results show that the number of ROADMs can be double in links with 4% guard-band superchannels.
We propose a new class of transceivers for secure communication and interference mitigation, operating over large bandwidths on the order of 10GHz. Specifically, a novel coding approach that combines frequency and code multiplexing is proposed. Equally important is power and hardware reduction by implementing a low power on-site coding with beamforming. The latter reduces power requirements for the...
This document aims at offering a concise look into the co-existence of Underwater Telephone and JANUS digital communication methods. This topic is of particular interest as both methods (one a well-established STANAG and the latter in the process to become a STANAG) have partially overlapping frequency bands. The two techniques are briefly described and the specific interference mitigation strategies...
Direct sequence spread spectrum (DSSS) is an optimal mode of coding for data communication. Spread spectrum coding were used in various communication modes, which gives an advantage of channel interference minimization, with maximum spectrum utilization. With the simplicity in coding efficiency, this coding approach was most effectively used in various application of data exchange. However, with the...
Through analysis of coding and decoding principle about countering the laser jamming, this paper focuses on a long and cyclic period of pseudo-random codec scheme, and it uses FPGA to implement the program according to the specific hardware requirements in order to achieve a better effect. The design is mainly used to counter the laser high PRF (pulse repetition frequency) jamming, of which implementation...
In this paper we implement a turbo based Overlay Cognitive radio Z-channel with Trellis shaping, where the primary and cognitive users transmits and receives concurrently, utilizing the same spectrum. We ensure that bit error rate (BER) performance of the Primary does not degrade even in the presence of cognitive user. We derive bit error rate BER curves for both users, and show significant improvement...
Holography is an emerging technology to represent and display visual information and the associated experience expectations on the layman imaginary are huge. A hologram is a reproduction of a light field represented through the interference pattern between two wavefields, the reference and object wavefields. Holograms may be optically generated from real objects or computationally generated from synthetic...
High frequency (HF) band covers frequencies between 3–30 MHz. With wavelengths of 10–100 m, HF band enables communications over a very long distances though a skywave propagation. As HF band has several benefits like versatility and large coverage area, it suffers phenomena like rapidly changing environment and strong interference. The cognitive radio concept which adapts to the changes in the environment...
Femtocells enhance indoor coverage of mobile services using the owner's broadband connection. They were initially designed to serve a number of subscribed User Equipments within their range. This design however, resulted in underutilization of the femtocells resources, and simultaneously in high interference levels for nearby non-subscribed users. Nowadays, femtocells can support multicast transmissions,...
Due to their linear and highly symmetrical structure, lattices are becoming of a great interest as potential transmission schemes. Lattice codes suggest a common view of channel and source coding and new tools for the analysis of information network problems. Several constructions have been proposed to build these lattices, some of which are based on multi-level coding and multistage decoding such...
In this paper, we investigate the impact of an arbitrary number of Rayleigh faded co-channel interferers with arbitrary powers on the performance of dual-hop transmission systems that employ amplify-and-forward relays. The received signals at the relay and destination undergo independent but not necessarily identical Nakagami-m fading. Analytical expressions for the exact and asymptotic outage probability...
Cooperative relay systems have drawn much attention in recent years because they can use an appropriate number of relays to form a virtual multiple-input multiple-output (MIMO) scenario to improve communication links. Also, space frequency block coding (SFBC) is a prominent strategy for MIMO systems, and it has been widely adopted with orthogonal frequency division multiplexing (OFDM) to achieve both...
In this paper, we characterize the stability region of the two-user broadcast channel. First, we obtain the stability region in the general case. Second, we consider the particular case where each receiver treats the interfering signal as noise, as well as the case in which the packets are transmitted using superposition coding and successive decoding is employed at the strong receiver.
Filter Bank MultiCarrier (FBMC) might replace Orthogonal Frequency Division Multiplexing (OFDM) in 5G. For such FBMC system, we derive closed-form expressions for the Bit Error Probability (BEP) including channel estimation, whereas we focus on the comparison of FBMC with OFDM. We assume additive white Gaussian noise and a Rayleigh fading channel with low delay spread and low Doppler spread, so that...
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...
In this work we identify a surprising effect by which searching for less repetitions in fast compressors can occasionally gain more compression (may reach up to a 30% improvement). Moreover, when executed on the correct data, restricting the repetition search manages to simultaneously improve both compression ratio and compression and decompression speeds. The rationale behind this phenomena is that...
The paper analyzes the stability issue of a special emulator of memristive, memcapacitive and meminductive systems as well as higher-order elements from Chua's periodical table, and other two-terminal devices. It is demonstrated that, in order to provide stable behavior, the analog port of the emulator must be implemented by the controlled voltage or current source depending on the type of the emulated...
In this paper, the problem of jointly allocating bits, subcarriers and power to maximize the total transmit bit rate in an OFDM based cognitive radio (CR) is studied. Moreover, different service requirements of SUs are also considered. Since “underlay“ is adopted as the spectrum shared model, secondary users (SU) in the CR system are allowed to utilize any part of frequency band as long as the interference...
This paper considers the two-user interference relay channel where each source wishes to communicate to its destination a message that is confidential from the other destination. Furthermore, the relay, that is the enabler of communication, due to the absence of direct links, is untrusted. Thus, the messages from both sources need to be kept secret from the relay as well. We provide an achievable...
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