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Copyright of Journal of Data Acquisition & Processing / Shu Ju Cai Ji Yu Chu Li is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, we investigate trade-off between security and reliability of Fountain codes (FCs) based low-energy adaptive clustering hierarchy (LEACH) networks, where the encoded packets are sent to the destination by using a cluster-based multi-hop transmission scheme with the assistance of cluster heads (CHs). With presence of an eavesdropper, a cooperative harvest-to-jam technique is employed to reduce the quality of the eavesdropping channels. Particularly, each cluster randomly selects a cluster node that generates artificial noises on the eavesdropper. For performance evaluation, we derive exact closed-form expressions of outage probability (OP) and intercept probability (IP) over Rayleigh fading channels. We then perform Monte Carlo simulations to verify the theoretical results, and compare the performance of the proposed scheme with that of the conventional LEACH scheme without using the jamming technique.

In this paper, we propose a rateless, three-stage, two-way multiply-and-forward (MF) relaying system over the Rayleigh flat fading channel, where two source nodes communicate with each other through a relay node and all nodes work on half-duplex and time-division mode. We thoroughly analyze the signals during all three stages in the proposed MF system and derive the closed-form symbol error rate (SER) expressions for an uncoded MF-two-way relay network (MF-TWRN). Furthermore, we provide the equivalent point-to-point fading channel model, which is employed to carry out the asymptotic performance analysis. We finally put forth an optimization model for the MF-TWRN with fountain codes. Simulation results show that our optimized degree distribution can provide outstanding performance for the MF-TWRN compared to those in the literature.

Machine-to-machine communication over long-term evolution advanced (LTE-A) network has emerged as a new communication paradigm to support a variety of applications of Internet of Things. One of the most effective techniques to accommodate a large volume of machine type communication (MTC) devices in LTE-A is clustering where devices (nodes) are grouped into number of clusters and forward their traffics to the base station (e.g., LTE eNodeB) through some special nodes called cluster heads (CHs). In many applications, the CHs change location with time that causes variation in distances between neighboring CHs. When these distances increase, the performance of data transmission may degrade. To address this issue, we propose to employ intermediate non-CH nodes as relays between neighboring CHs. Our solution covers many aspects from relay selection to cooperative formation to meet the user's QoS requirements. As the number of total relay plays a significant role in cooperative communications, we first design a rateless-coded-incremental-relay selection algorithm based on greedy techniques to guarantee the required data rate with a minimum cost. After that, we develop both source-feedback and non-source-feedback-based fountain coded cooperative communication protocols to facilitate the data transmission between two neighbor CHs. Numerical results are presented to demonstrate the performance of these protocols with different relay selection methods under Rayleigh fading channel. It shows that the proposed source-feedback-based protocol outperforms its non-source-feedbackprotocol counterpart in terms of a variety of metrics.

This paper investigates the system performance evaluation framework of systematic rateless-coded (SRCed) transmissions for user experience in future 5G systems. To this end, we define the application-layer information loss ratio (AILR), i.e., the ratio of the number of unsuccessfully decoded messages to that of the total transmitted messages, as a system performance index from the perspective over network application layer, which can be used as an evaluation framework on the users' experience in the viewpoint of 5G transmission systems. By using the integer partition theory, we analytically derive some theoretical results and then obtain an exact expression of the AILR for SRCed transmissions. Simulation and numerical results are provided to demonstrate the validness of our analytical results, which also show that the SRCed transmission achieves much better system performance than existing coded transmission methods in terms of AILR. Moreover, by using our presented AILR expression, the proper system configuration can be easily determined without a heavy burden of Monte Carlo simulations. It also illustrates some inherent relationships between system parameters by using SRCed transmission on application layer, which can be easily carried out to achieve a better performance in the viewpoint of users' experiences. First, for a given channel condition, the larger the message length is, the smaller the ratio of the message length to the source symbol length should be selected. Second, for a given message length, the better the channel condition is, the larger the ratio of the message length to the source symbol length should be selected.

Erasure codes for distributed storage systems (DSS) are required to offer systematic encoding, low repair locality, low encoding/decoding complexity, and low decoding/storage overhead. However, the information theoretical bounds have shown that all these metrics might need to be carefully traded-off with one another. In this paper, we consider systematic Fountain codes with belief propagation (BP) decoding for massive scale DSSs. Analyzing the role of some degrees in the BP decoding process, we propose using the truncated Poisson distribution (TPD) for encoded symbol degrees. Identifying encoded symbol redundancy as a factor that degrades decoding overhead, we derive the probability of redundancy during the BP decoding process and use this as a tool for determining the Poisson parameter. Our proposed solution nicely addresses the first three DSS metrics with a slight toll on storage/decoding overhead. Through simulations, we show that the decoding overhead performance of the proposed scheme exhibits significant improvement over some existing Fountain code degree distributions in the literature. For instance, at a decoding overhead of 60%, we achieve a data loss probability closely approaching $10^{-4}$ , while other Fountain codes compared are about a factor of 102 higher. [ABSTRACT FROM AUTHOR]

Memory-based LT encoders (MBLTEs) have been shown to have better performance than the regular LT encoder in terms of bit error rate (BER) and decoding convergence speed. In this paper, we explore the entire family of MBLTEs for finite block-length codes over the binary erasure channel (BEC). We propose an algorithm to extend the first and second order MBLTE approach to an arbitrary $i$ -th order MBLTE. We analyze the performance of such encoders mathematically by characterizing the expected accumulated number of recovered variable nodes at each decoding round. We define the threshold of the memory-based encoding method (MBEM) and show that the performance of MBLTEs increases as the memory order increases up to the point where this threshold is achieved. Beyond this point, we show that the performance of MBLTEs saturates if the channel erasure probability is zero and degrades otherwise. We formulate an optimization problem to solve for the optimal memory order based on whether or not the MBEM threshold is achieved. We present an extensive set of numerical results. These show agreement between our analysis and computer simulations. They also show that our optimization problem is efficient in determining the optimal memory order of MBLTEs in terms of decoding convergence speed, BER/frame-error-rate, and error floor. [ABSTRACT FROM AUTHOR]

The online property of fountain codes enables the encoder to efficiently find the optimal encoding strategy that minimizes the encoding overhead based on the instantaneous decoding state. Therefore, the receiver is able to optimally recover data from losses that differ significantly from the initial expectation. In this paper, we propose a framework to analyze the relationship between overhead and the number of recovered source symbols for online fountain codes based on random graph theory. Motivated by the analysis, we propose improved online fountain codes (IOFCs) by introducing a designated selection of source symbols. Theoretical analysis shows that IOFC has lower overhead compared with the conventional online fountain codes. We verify the proposed analysis via simulation results and demonstrate the tradeoff between full recovery and intermediate performance in comparison to other online fountain codes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article describes and evaluates the performance of DETIboot, a system conceived for securely deploying temporary Linux systems into countless receiving hosts close enough to a Wi-Fi DETIboot server. This system was created with the ultimate goal of installing, in numerous students’ laptops and just-in-time, special Linux distributions for being temporarily used in practical classes. In this document we present an overview of DETIboot, a comprehensive description of the coding used in the broadcast communication and a detailed performance evaluation in a spacious auditorium. This evaluation did not involve security features to reduce the amount of variables influencing the final results. However, previous experiments allow us to extrapolate a maximum of 5% increase in the download time due to security. On average, it took us 50.1 s to download a 225 MiB Slax Linux over 802.11g, taking on average 15% more time than the theoretical lower bound of our setup (43.4 s). The influence of the position of receivers in the auditorium was not prominent. [ABSTRACT FROM AUTHOR]

Pushing and caching are recognized as promising techniques to improve network capacity and handle explosive growth in data traffic. Caching schemes for synchronous requests have been extensively investigated, but little attention has been paid to the asynchronous case. However, asynchronism is an inherent property of user requests. In this paper, request delay information (RDI) is introduced to characterize the asynchronous user requests. Based on RDI, a coded joint pushing and caching (C-JPC) method is proposed to minimize the network traffic by jointly determining when and which data packets are to be pushed and whether they should be cached. Optimal offline and online C-JPC policies for noncausal and causal RDI can be obtained by solving optimization problems, which however are intractable. Fountain coded caching (FCC) and generalized coded caching (GCC) methods are further proposed to give sub-optimal C-JPC policies with low complexity. In addition, lower and upper bounds on the optimal traffic volume are presented. It is shown that FCC and GCC achieve optimal or near-optimal volumes of traffic in some special cases. Simulation results demonstrate that C-JPC brings significant multicasting gains. [ABSTRACT FROM AUTHOR]

This paper proposed a secure transmission scheme using the feedback based fountain code aiming at reducing the demand of superiority on the main channel. In the binary erasure channel model, legitimate user sent feedback to transmitter, sharing the decoding situation of input symbols. Then, the encoder updated the coding process based on the feedback messages. It could expand the decoding gap and accumulate the superiority of legitimate user in decoding results. Numerical results show that the proposed method can reduce the intercepting rate of eavesdropper under the same channel conditions especially when the channel quality is close. [ABSTRACT FROM AUTHOR]

In this paper, we propose and evaluate the performance of fountain codes (FCs) based secure transmission protocols in multiple-input-multiple-output (MIMO) wireless systems, in presence of a passive eavesdropper. In the proposed protocols, a source selects its best antenna to transmit fountain encoded packets to a destination that employs selection combining (SC) or maximal ratio combing (MRC) to enhance reliability of the decoding. The transmission is terminated when the destination has a required number of the encoded packets to reconstruct the original data of the source. Similarly, the eavesdropper also has the ability to recover the source data if it can intercept a sufficient number of the encoded packets. To reduce the number of time slots used, the source can employ non-orthogonal multiple access (NOMA) to send two encoded packets to the destination at each time slot. For performance analysis, exact formulas of average number of time slots (TS) and intercept probability (IP) over Rayleigh fading channel are derived and then verified by Monte-Carlo simulations. The results presented that the protocol using NOMA not only reduces TS but also obtains lower IP at medium and high transmit signal-to-noise ratios (SNRs), as compared with the corresponding protocol without using NOMA.

Expanding window fountain (EWF) codes, which can provide unequal erasure protection property, are used as an efficient application-layer forward error correction solution for scalable multimedia data transmission over packet networks. Similar to Raptor codes, precoded EWF codes can provide linear coding complexity. However, only when the information length is large, the precoded EWF codes in previous literatures can achieve good performance. In this paper, we carefully investigate how to choose code rates of precodes and degree distributions of EWF codes for different information lengths. Our proposed precoded EWF coding scheme can achieve superior performance compared to the previous scheme for small and moderate information lengths. Simulation results for the scalable video coding extension of the H.264/AVC standard show that, compared with the previous scheme, our proposed scheme requires a smaller reception overhead to recover the base layer. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the utilization of Raptor code for performance enhancement of Orthogonal Frequency Division Multiplexing (OFDM) systems. Unlike classical channel coding techniques which have fixed code rates, Raptor code is a rateless code. Raptor code has proved to have a wonderful performance over a class of wireless channels. Simulation experiments have been carried out to investigate the performance of Raptor code with OFDM. Different modulation schemes have been used in the simulation experiments such as Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), and Quadrature Amplitude Modulation (QAM). The Bit Error Rate (BER) has been used as the evaluation metric for the proposed Raptor-OFDM system. Simulation results reveal a good performance of the proposed system. [ABSTRACT FROM AUTHOR]

In this paper, we analyze Luby transform (LT) and Raptor codes under inactivation decoding. A first-order analysis is introduced, which provides the expected number of inactivations for an LT code, as a function of the output distribution, the number of input symbols, and the decoding overhead. The analysis is then extended to the calculation of the distribution of the number of inactivations. In both cases, random inactivation is assumed. The developed analytical tools are then exploited to design LT and Raptor codes, enabling a tight control on the decoding complexity versus failure probability tradeoff. The accuracy of the approach is confirmed by numerical simulations. [ABSTRACT FROM AUTHOR]

Spreading a large file consisting of many packets over a mobile network is challenging due to the short meeting duration for each transmission. Moreover, two typical causes of inefficient file spreading are duplicate packet reception at the destination nodes and excessive overhead exchanges. We propose to employ fountain codes at the source node to jointly addresses the three issues: 1) each coded packet can be small enough to fit into the meeting duration; 2) duplicate packet reception is significantly reduced since each coded packet is innovative; and 3) overhead is greatly saved by using file-level ACK instead of packet-level ACK. We conduct performance analysis in terms of the source-to-destination file delay and source-to-destination file spreading time in both non-relaying and relaying scenarios. While packet duplication can be eliminated in the former scenario, there is still a non-trivial duplication probability if relaying is allowed. Therefore, we propose a fountain-coded two-hop relaying (FTTR) protocol to further reduce the packet duplication ratio so that the spreading performance does not degrade with network size. The file spreading time and packet duplication ratio of FTTR are derived in closed form and verified through simulations. [ABSTRACT FROM PUBLISHER]

In this paper, an improved encoding scheme for online fountain codes is proposed with the joint optimization of variable node degree and check node degree is proposed. The coding scheme can be divided into the build-up phase and the completion phase. In the build-up phase, left degree distribution is exploited to guarantee optimal performance phase by modifying the traditional coding scheme of choosing input symbols uniformly at random. A memory-based selecting of the source symbols is employed to decrease the number of connected components, which can thus produce the dimension increasement of the linear subspace of a decoding graph constructed in the build-up phase. The upper bound on coding overhead is also derived from the analysis of random graph theory. Compared with conventional online fountain codes, it can be seen from the simulation results that the proposed scheme can provide significant performance improvement with respect to both coding overhead and feedback cost. Moreover, the lower encoding/decoding complexities may make the proposed scheme more practical in energy-constrained applications such as distributed storage. [ABSTRACT FROM AUTHOR]

The transmission of video files in Vehicular Adhoc Networks (VANETs) has become very prevalent as commuters prefer video data during travel. The delay with which the data is received becomes very significant as video packets received after their scheduled deadlines become useless. The performance of the network may significantly be reduced on such packet drops especially with mobile networks. This work aims at the reduction of end to end delay of video packets by applying the two techniques- Network Coding (NC) and RaptorQ (RQ) codes. The techniques are implemented in four VANET scenarios and an extensive analysis is done by varying the packet sizes during the transmission of three files of various sizes. The End to End Delay (EED) and Packet Delivery Ratio (PDR) are measured and plotted for all scenarios. The results show the influence of packet size on these parameters considered and the suitability of the techniques applied. The observations also show that RQ proves better for smaller files and NC suits better when the file size increases. [ABSTRACT FROM AUTHOR]

Luby Transform (LT) codes play an important role in both data transmission and storage, but it is still a challenging problem that how to analyze their performance due to the degree distributions. In this letter, a novel methodology to analyze the performance of LT codes is proposed. This method establishes a probability transfer model between two adjacent steps of the belief propagation decoding algorithm, and provides an intuitive and unifying tool to analyze finite length LT codes. We first present the comprehensive description and theoretical identification of the proposed methodology, and then give some simulation results to validate its effectiveness. [ABSTRACT FROM PUBLISHER]

We consider a multihop network where a source node must reliably deliver a set of data packets to a given destination node. To do so, the source applies a fountain code and floods the encoded packets through the network, until they reach their destination or are lost in the process. We model the probability that the destination can recover the original transmissions from the received coded packets as a function of the network topology and of the code redundancy, and show that our analytical results predict the outcome of simulations very well. These results are employed to design distributed forwarding policies that achieve a good tradeoff between the success probability and the total number of transmissions required to advance a packet toward the destination. We finally develop in detail the case where intermediate relays can inject additional redundancy in the network, provided that they have successfully decoded the source packets. [ABSTRACT FROM PUBLISHER]

A new encoding scheme for on-line fountain codes is proposed to provide unequal error protection (UEP) for source symbols. Both the weighted-selection strategy and the expanding-window strategy are used to achieve the UEP property. We analyze the bound of overhead to demonstrate the performance. We also make comparisons with on-line fountain codes that provide equal error protection. Simulation results show that with the proposed scheme, UEP is achieved, where the most important symbols are recovered faster than the least important symbols. [ABSTRACT FROM PUBLISHER]

Underwater acoustic networks (UAN) allow for efficiently exploiting and monitoring the sub-aquatic environment. These networks are characterized by long propagation delays, error-prone channels and half-duplex communication. In this paper, we address the problem of energy-efficient communication through the use of optimized channel coding parameters. We consider a two-layer encoding scheme employing forward error correction (FEC) codes and fountain codes (FC) for UAN scenarios without feedback channels. We model and evaluate the energy consumption of different channel coding schemes for a K-distributed multipath channel. The parameters of the FEC encoding layer are optimized by selecting the optimal error correction capability and the code block size. The results show the best parameter choice as a function of the link distance and received signal-to-noise ratio. [ABSTRACT FROM AUTHOR]

This paper presents Pando, a completely contention-free data dissemination protocol for wireless sensor networks. Pando encodes data by Fountain codes and disseminates the rateless stream of encoded packets along the fast and parallel pipelines built on constructive interference and channel diversity. Since every encoded packet contains innovative information to the original data object, Pando avoids duplicate retransmissions and fully exploits the wireless broadcast effect in data dissemination. To transform Pando into a practical system, we devise several techniques, including the integration of Fountain coding with the timing-critical operations of constructive interference and pipelining, a silence-based feedback scheme for the one-way pipelined dissemination, and packet-level adaptation of network density and channel diversity. Based on these techniques, Pando can accomplish data dissemination entirely over the fast and parallel pipelines. We implement Pando in Contiki and for TelosB motes. We evaluate Pando with various settings on two large-scale open test beds, Indriya and Flocklab. Our experimental results show that Pando can provide 100% reliability and reduce the dissemination time of state of the art by $3.5\times $ . [ABSTRACT FROM AUTHOR]

Raptor codes can provide good error correction capability and efficient encoding and decoding rate. Its fountain code property is effective in avoiding packet retransmission for both unicast and multicast service delivery. Hence, there are many mobile, vehicular and broadband applications adopting it such as mobile multimedia broadcasting, multimedia communications for high-speed rails and broadband IPTV systems. In this paper, we present an efficient systematic Raptor codes encoder based on operation lists for known source block lengths. For a Raptor codes application that can frequently use one or several fixed source block lengths (i.e., the number of source symbols in a source block), we could produce the corresponding operation lists in advance and use them to generate the encoding symbols more efficiently. We first introduce the basic architecture of the proposed Raptor encoder, and then describe the details about how to generate operation lists and Raptor intermediate symbols. The simulation results show that our encoder is at least two times faster than the conventional Raptor codes encoder which is adopted by 3GPP and DVB-H. Besides, the reduction on CPU utilization for a real Raptor-based streaming server is described, which is from 11.59 % to 53.41 %, depending on the employed source block length and symbol size. [ABSTRACT FROM AUTHOR]

Using total transmission time-the time needed to guarantee reliable data dissemination——as judgment criterion,the payload length selection problem was investigated for three multicast solutions which are based on simple feedback retransmission,Reed-Solomon codes,and LT fountain codes,respectively,with the consideration of packet overhead.A theoretical analysis method was proposed to determine the optimal payload lengths,which was verified by simulations.Analyses and simulations indicate,for variable packet overhead sizes and link bit error rates,each method considered has its optimal payload length.As link bit error rate increases,the performance gain brought by the selection of optimal pay-load lengths becomes more significant.Among the three solutions,the reliable multicast solution based on LT fountain codes has the most outstanding performance.

In order to reduce the complexity of transmission protocols and the number of feedback links,fountain code was applied to the multi-stage parallel relay network for open-loop error control.The fountain code based network trans-mission scheme and frame format were presented.The transmission time for both the fountain code based scheme and the conventional ARQ based scheme was analyzed and compared.Results show that the total time consumed under fountain code based scheme can be significantly reduced compared to the ARQ based scheme.With the increase of relay numbers,the advantage of the fountain code based scheme is more evident.

In this paper, two classes of fountain codes, called batched zigzag fountain codes and two-phase batched zigzag fountain codes, are proposed for the symbol erasure channel. At a cost of slightly lengthened code symbols, the involved message symbols in each batch of the proposed codes can be recovered by low complexity zigzag decoding algorithm. Thus, the proposed codes have low buffer occupancy during decoding process. These features are suitable for broadcasting to receivers with limited hardware resources. We also propose a method to obtain degree distributions of code symbols for the proposed codes via ripple size evolution by taking into account the released code symbols from the batches. We also show that the proposed codes outperform Luby transform codes and zigzag decodable fountain codes with respect to intermediate recovery rate and coding overhead when message length is short, symbol erasure rate is low, and available buffer size is limited. [ABSTRACT FROM PUBLISHER]

Joint FoUntain coding and Network coding (FUN) is proposed to boost information spreading over multi-hop lossy networks. The novelty of our FUN approach lies in combining the best features of fountain coding, intra-session network coding, and cross-next-hop network coding. This paper provides an in-depth study of FUN codes. First, we theoretically analyze the throughput of FUN codes. Second, we identify several practical issues that may undermine the actual performance, such as buffer overflow, and quantify the resulting throughput degradation. Finally, we propose a systematic design to overcome these issues. Simulation results in TDMA multi-hop networks show that our methods yield near-optimal throughput and are significantly better than fountain codes and existing network coding schemes. [ABSTRACT FROM PUBLISHER]

Underwater Acoustic Sensor Networks (UASNs) have attracted increasing interest in recent years due to their extensive commercial and military applications. However, the harsh underwater channel causes many challenges for the design of reliable underwater data transport protocol. In this paper, we propose an energy efficient data transport protocol based on network coding and hybrid automatic repeat request (NCHARQ) to ensure reliability, efficiency and availability in UASNs. Moreover, an adaptive window length estimation algorithm is designed to optimize the throughput and energy consumption tradeoff. The algorithm can adaptively change the code rate and can be insensitive to the environment change. Extensive simulations and analysis show that NCHARQ significantly reduces energy consumption with short end-to-end delay. [ABSTRACT FROM AUTHOR]

In this paper, we study systematic Luby transform (SLT) codes over binary input additive white Gaussian noise (BIAWGN) channels. To improve the bit-error-rate (BER) performance of SLT codes on the BIAWGN channel, this paper presents a novel optimization design of degree distributions. First, we apply the Gaussian approximation (GA) to analyze the asymptotic BER performance of SLT codes and calculate overhead thresholds for successful decoding. Second, we derive an approximate closed-form expression for lower bound on BER by applying the GA and further simplify the expression in low and high signal-to-noise ratio regimes, respectively. Third, we adopt the conventional linear programming (CLP) constrained by the GA to optimize the degree distribution of SLT codes. The objective of CLP is to minimize the average degree of the degree distribution that may result in bad error floor. To improve the error floor caused by CLP, we put forth a novel optimization model constrained by the lower bound on BER, and using the model we can design the degree distribution more flexibly with any desired BER. Simulation results show that the proposed degree distribution can provide better BER performance of SLT codes over the BIAWGN channel. [ABSTRACT FROM AUTHOR]

In this letter, we provide the construction of repairable fountain codes (RFCs) for distributed storage systems that are information-theoretically secure against an eavesdropper that has access to the data stored in a subset of the storage nodes and the data downloaded to repair an additional subset of storage nodes. The security is achieved by adding random symbols to the message, which is then encoded by the concatenation of a Gabidulin code and an RFC. We compare the achievable code rates of the proposed codes with those of secure minimum storage regenerating codes and secure locally repairable codes. [ABSTRACT FROM PUBLISHER]

One key requirement for fountain (rateless) coding schemes is to achieve a high intermediate symbol recovery rate. Recent coding schemes have incorporated the use of a feedback channel to improve the intermediate performance of traditional rateless codes; however, these codes with feedback are designed based on uniformly at random selection of input symbols. In this paper, on the other hand, we develop feedback-based fountain codes with dynamically adjusted nonuniform symbol selection distributions, and show that this characteristic can enhance the intermediate decoding rate. We provide an analysis of our codes, including bounds on computational complexity and failure probability for a maximum likelihood decoder; the latter is tighter than bounds known for classical rateless codes. Through numerical simulations, we also show that the feedback information paired with a nonuniform selection distribution can highly improve the symbol recovery rate, and that the amount of feedback sent can be tuned to the specific transmission properties of a given feedback channel. [ABSTRACT FROM PUBLISHER]

In this paper, we propose an efficient scheme to construct fountain codes that can provide unequal error protection (UEP) property. To reduce the coding complexity and improve the performance of previous duplicate UEP schemes in the literature, we implement different rate low-density parity-check codes instead of the duplication process and replace the high-complexity classical robust soliton distribution by low constant average degree distributions with high intermediate symbol recovery rates. Asymptotic analysis of both the duplicate scheme and our scheme is obtained by deriving unequal density evolution formulas over the binary erasure channel. Compared to previous UEP schemes, our scheme has lower complexity. Experimental results show that our scheme can obtain better decoding performance, especially for smaller input information length. Comparison of peak signal-noise ratio performance for the scalable video coding shows that, for moderate input information length, our scheme can provide a better basic video quality at lower overhead, but needs larger overhead to achieve a high video quality. [ABSTRACT FROM PUBLISHER]

This article investigates the distributed data storage problem in the space information network (SIN) using distributed fountain codes. Since space nodes in the SIN are resource-limited, in order to reduce energy consumption while improving the storage reliability, an efficient distributed storage based on fountain codes and probabilistic broadcasting (DSFPB) strategy is proposed. In the proposed strategy, source packets are disseminated among the entire network according to probabilistic broadcasting (PBcast), and the final degree distribution is close to the desired robust soliton distribution (RSD), this is benefited from the appropriate packets encoding procedure of the proposed strategy. As presented by the analysis and simulations, the total cost of data dissemination is greatly reduced compared with existing representative strategies, while improving the decoding performance. [ABSTRACT FROM AUTHOR]

We propose a fountain coding aided CCSDS file-delivery protocol (FCFDP) and analyze its deferred negative acknowledgment (NAK) automatic repeat-request (ARQ) scheme. For ideal fountain codes, an expression for the expected number of retransmission spurts in the FCFDP is derived. The analytical and simulation results show that the expected number of retransmission spurts decreases with the increase of redundant packets. If there are sufficient redundant packets, the expected number of retransmission spurts is close to zero. Therefore, the delays introduced by propagation in deep space communications are dramatically reduced. [ABSTRACT FROM PUBLISHER]

This paper presents a novel fountain code-based hybrid P2P and cloud storage system. While most cloud storage systems guarantees data retrievability of high level, they may be vulnerable to data privacy since the stored data may be exposed to others by accident or design. On the other hand, P2P storage system keeps any peer from accessing the whole data by dividing the data into small pieces and distributing them to multiple participating peers, but may degrade data retrievability due to unstable peers. The proposed hybrid storage system attempts to enhance data retrievability and privacy by effectively distributing fountain encoded symbols to cloud server system and participating peers. It is demonstrated that the proposed hybrid storage system achieves the desired level of data retrievability with a short upload time, and enhance privacy by preventing others from reading the contents. [ABSTRACT FROM AUTHOR]

Cooperative relaying communications is an efficient paradigm for end-to-end data delivery in industrial wireless sensor networks. However, due to the broadcast nature of radio propagation, it is challenging to guarantee the secrecy of cooperative transmissions under eavesdropping attacks. To deal with this issue, a fountain-coding aided relaying scheme is proposed in this paper, for which all the source packets are first encoded with fountain codes (FCs) and then transmitted over the channels. Based on the basic characteristic of FC transmissions, a sufficient number of coded packets have to be successfully received to recover the original data. Therefore, transmission secrecy is guaranteed if the legitimate receiver can accumulate the required number of FC packets before the eavesdropper does. To satisfy this condition, a cooperative jamming method is utilized to worsen the received signal quality at the eavesdropper. By applying the constellation rotation approach, the information-bearing signal and the jamming signal are designed carefully to reduce the negative effect of the jamming procedure on the legitimate receiver. To evaluate how the scheme behaves in wireless fading channels, the authors propose a novel performance metric, i.e., the quality-of-service violating probability (QVP), and derive its closed-form expression. Compared to the commonly used metrics in physical-layer security such as secrecy outage probability, QVP can give a more comprehensive performance evaluation for the system, including the delay, the reliability, and the security level as well. Finally, the theoretical analysis is validated by simulation results. [ABSTRACT FROM PUBLISHER]

Raptor code ensembles with linear random outer codes in a fixed-rate setting are considered. An expression for the average distance spectrum is derived and this expression is used to obtain the asymptotic exponent of the weight distribution. The asymptotic growth rate analysis is then exploited to develop a necessary and sufficient condition under which the fixed-rate Raptor code ensemble exhibits a strictly positive typical minimum distance. The condition involves the rate of the outer code, the rate of the inner fixed-rate Luby Transform (LT) code and the LT code degree distribution. Additionally, it is shown that for ensembles fulfilling this condition, the minimum distance of a code randomly drawn from the ensemble has a linear growth with the block length. The analytical results can be used to make accurate predictions of the performance of finite length Raptor codes. These results are particularly useful for fixed-rate Raptor codes under maximum likelihood erasure decoding, whose performance is driven by their weight distribution. [ABSTRACT FROM AUTHOR]