systematic coding of observed human behaviour (SCOBe) is used across disciplines and topics but methodological reporting is often incomplete. We developed internationally generated, interdisciplinary guidelines for me...
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Network steganography is an information hiding technique that utilizes network protocols to facilitate hidden communication. The aim is to embed secret information bits into regular network traffic (as a carrier) so t...
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Network steganography is an information hiding technique that utilizes network protocols to facilitate hidden communication. The aim is to embed secret information bits into regular network traffic (as a carrier) so that confidential data can be transmitted covertly between two communicating parties. In this paper, the concept of network steganography is extended for overlay cognitive radio networks utilizing cooperative relaying protocols with systematic channel codes. In the considered model, the cognitive node relays the primary data according to a time-slotted decode-and-forward cooperative protocol with maximum-ratio combining (MRC) at the primary destination. We propose a steganographic approach in which the cognitive node embeds confidential cognitive data at the wavelet transform domain into primary data code words. In this approach, the embedding operation is designed to preserve the statistical properties of the cover data in terms of decoded BER after MRC decoding of code words at the destination node which includes both the effect of wireless channel errors and errors due to embedding distortion. From this point of view, the proposed scheme may be seen as a lossless steganography scheme that embeds secret data into coded data strings. We provided implementation examples using both systematic BCH and turbo channel coding. The results show that the proposed scheme can provide diversity gain using stego-based MRC at the primary receiver and covert confidential cognitive data communications simultaneously. (C) 2018 Elsevier B.V. All rights reserved.
The presence of IoT in current networking scenarios is more relevant every day. IoT covers a wide range of applications, ranging from wearable devices to vehicular communications. With the consolidation of Industry 4....
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ISBN:
(纸本)9781728133164
The presence of IoT in current networking scenarios is more relevant every day. IoT covers a wide range of applications, ranging from wearable devices to vehicular communications. With the consolidation of Industry 4.0, IIoT (IndustrialIoT) environments are becoming more common. Communications in these scenarios are mostly wireless, and due to the lossy nature of wireless communications, the loss of information becomes an intrinsic problem. However, loss recovery schemes increase the delay that characterizes any communication. On the other hand, both reliability (robustness) and low delay are crucial requirements for some applications in IIoT. An interesting strategy to improve both of them is the use of Network coding techniques, which have shown promising results, in terms of increasing reliability and performance. This work focuses on a possible new coding approach, based on systematic network coding scheme with overlapping generations. We perform a thorough analysis of its behavior. Based on the results, we draw out a number of conclusions for practical implementations in wireless networks, focusing our interest in IIoT environments.
In this paper we compare two schemes for error-resilient video transmission, viz., systematic lossy error protection, and scalable coding with unequal error protection. In the first scheme, the systematic portion cons...
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ISBN:
(纸本)0819456586
In this paper we compare two schemes for error-resilient video transmission, viz., systematic lossy error protection, and scalable coding with unequal error protection. In the first scheme, the systematic portion consists of the compressed video signal transmitted without channel coding. For error-resilience, an additional bitstream generated by Wyner-Ziv encoding of the video signal is transmitted. In the event of channel errors, the Wyner-Ziv description is decoded using the error-prone systematic description as side-information. In the second scheme, the video bitstream is partitioned into two or more layers, and each layer is assigned different amounts of parity information depending upon its relative significance. Since the base layer has heavy protection, a certain minimum video quality is guaranteed at the receiver. We compare experimentally, the performance of the competing schemes, for a particular application, i.e., Error-resilient digital video broadcasting. It is shown that systematic lossy error protection ensures graceful degradation of video quality without incurring the loss in rate-distortion performance characteristic of practical layered video coding schemes.
We extend the setting of two-stage lossy source coding with successive refinement structures into a joint source-channel coding setting. In particular, we consider a problem where two descriptions of a memoryless sour...
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We extend the setting of two-stage lossy source coding with successive refinement structures into a joint source-channel coding setting. In particular, we consider a problem where two descriptions of a memoryless source are to be transmitted across two independent memoryless channels and where the output of the channel corresponding to the first (coarse) description is also available to the decoder of the second (refinement) decoder. Side information (SI), correlated to the source, may also be available to the decoders. In such a case, we confine attention to degraded SI, in the sense that the source, the SI available at the refinement decoder, and the SI available at the coarse decoder form a Markov chain in this order. Our first result is a separation theorem asserting that in the limit of long blocks, no optimality is lost by first applying lossy successive-refinement source coding, regardless of the channels, and then applying good channel codes to each one of the resulting bitstreams, regardless of the source and the SI. It is also shown that (even noiseless) feedback from the output of the first channel to the input of the second encoder cannot improve performance, but may sometimes significantly facilitate the implementation of optimum codes. We provide two examples where single-letter codes (of unit block length) achieve optimum performance, if feedback from the channel output of the first stage is provided to the encoder of the refinement stage. In one of these examples, it is evident that if feedback is not provided, optimality cannot be achieved with unit length code. Motivated by these examples, we then investigate single-letter codes for this system. Necessary and sufficient conditions are furnished for the optimality of single-letter codes with and without feedback. A corollary of these conditions is that for the quadratic distortion measure, feedback is necessary to achieve optimality in single-letter codes, regardless of the source distribution and t
The cyclic codes are used to encode information and their name comes from the fact that any cyclic permutation of a valid code word produces all a valid code word. In this paper we make a simulation performed using Ma...
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The cyclic codes are used to encode information and their name comes from the fact that any cyclic permutation of a valid code word produces all a valid code word. In this paper we make a simulation performed using Matlab Simulink simulation programming environment for some polynomial generators
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