Rateless Codes Research Articles

Dynamic Cooperative Communications with Mutual Information Accumulation for Mobile Robots in Industrial Internet of Things.

Mobile robots play an important role in the industrial Internet of Things (IIoT); they need effective mutual communication between the cloud and themselves when they move in a factory. By using the sensor nodes existing in the IIoT environment as relays, mobile robots and the cloud can communicate through multiple hops. However, the mobility and delay sensitivity of mobile robots bring new challenges. In this paper, we propose a dynamic cooperative transmission algorithm with mutual information accumulation to cope with these two challenges. By using rateless coding, nodes can reduce the delay caused by retransmission under poor channel conditions. With the help of mutual information accumulation, nodes can accumulate information faster and reduce delay. We propose a two-step dynamic algorithm, which can obtain the current routing path with low time complexity. The simulation results show that our algorithm is better than the existing heuristic algorithm in terms of delay.

Optimized Degree Distribution of Rateless Codes With Lower Complexity

Optimized Degree Distribution of Rateless Codes With Lower Complexity

FLoRa+: Energy-efficient, Reliable, Beamforming-assisted, and Secure Over-the-air Firmware Update in LoRa Networks

The widespread deployment of unattended LoRa networks poses a growing need to perform Firmware Updates Over-The-Air (FUOTA). However, the FUOTA specifications dedicated by LoRa Alliance fall short of several deficiencies with respect to energy efficiency, transmission reliability, multicast fairness, and security. This article proposes FLoRa+ , energy-efficient, reliable, beamforming-assisted, and secure FUOTA for LoRa networks, which is featured with several techniques, including delta scripting, channel coding, beamforming, and securing mechanisms. Specifically, we first propose a joint differencing and compression algorithm to generate the delta script for processing gain, which unlocks the potential of incremental FUOTA in LoRa networks. Then, we design a concatenated channel coding scheme with outer rateless code and inner error detection to enable reliable transmission for coding gain. Afterward, we develop a beamforming strategy to avoid biased multicast and compromised throughput for power gain. Finally, we present a securing mechanism incorporating progressive hash chain and packet arrival time pattern verification to countermeasure firmware integrity and availability attacks for security gain. Experimental results on a 20-node testbed demonstrate that FLoRa+ improves transmission reliability and energy efficiency by up to 1.51× and 2.65× compared with LoRaWAN. Additionally, FLoRa+ can defend against 100% and 85.4% of spoofing and Denial-of-Service (DoS) attacks.

A Partial Compress-and-Forward Strategy for Relay-Assisted Wireless Networks Based on Rateless Coding

A Partial Compress-and-Forward Strategy for Relay-Assisted Wireless Networks Based on Rateless Coding

Intelligent deep reinforcement learning-based scheduling in relay-based HetNets

We consider a fundamental file dissemination problem in a two-hop relay-based heterogeneous network consisting of a macro base station, a half-duplex relay station, and multiple users. To minimize the dissemination delay, rateless code is employed at the base station. Our goal is to find an efficient channel-aware scheduling policy at the half-duplex relay station, i.e., either fetch a packet from the base station or broadcast a packet to the users at each time slot, such that the file dissemination delay is minimized. We formulate the scheduling problem as a Markov decision process and propose an intelligent deep reinforcement learning-based scheduling algorithm. We also extend the proposed algorithm to adapt to dynamic network conditions. Simulation results demonstrate that the proposed algorithm performs very close to a lower bound on the dissemination delay and significantly outperforms baseline schemes.

Optimize the Network Coding Paths to Enhance the Coding Protection in Wireless Multimedia Sensor Network

Efficient protection techniques for multimedia data transfer over Wireless Sensor Network (WSN) are very essential issues. In noisy Wireless Multimedia Sensor Networks (WMSN) Quality of Service (QoS) is a challenging task due to bandwidth and limited energy, and unpredictable channel conditions. Therefore, Forward Error Correction (FEC), a class of channel coding has been widely used in WSN. Nevertheless, the bulky size of multimedia data makes it more difficult to be transported over the noisy multi-hop wireless network. Moreover, the efficiency of FEC drops as the number of hops increases. In this paper, an optimized protection technique based on network coding and rateless code has been proposed to enhance the throughput and reduce overhead during data transfer in WMSN. The performance of NCP-OPR is enhanced via Optimal Network Path Model (ONPM) where the best available paths are optimally selected using Particle Swarm Optimization (PSO). In conjunction with the proposed protection scheme, the proposed ONPM is intended for limited power WSN by optimally distributing the power usage among the network paths so that the throughput can be improved.

FDOE: Exploit Concurrent Communication Opportunities in Full-Duplex Wireless Mesh Networks

In recent years, full-duplex communications in a single frequency channel have become a practical technology. However, existing full-duplex medium access control (MAC) protocols can hardly take full advantages of full-duplex transmission opportunities, because they are not capable of adding one more half-duplex link on an on-going half-duplex link to form a full-duplex link. Besides, the exposed node and hidden node issues in multi-hop wireless networks limit flexible establishment of full-duplex links. Such limitations waste full-duplex transmission opportunities, and thus degrade network performance. In this paper, an efficient full-duplex link establishment protocol called full-duplex opportunity exploitation (FDOE) is developed to exploit full-duplex transmission opportunities in a wireless mesh network. FDOE leverages rateless coding and pseudo-noise (PN) sequences to establish a full-duplex link whenever a full-duplex transmission opportunity is available. Such a distinct feature leads to significant improvement of network performance. FDOE is evaluated through theoretical analysis and extensive simulations. Performance results show that FDOE exploits full-duplex transmission opportunities efficiently in wireless mesh networks, and thus significantly outperforms existing MAC protocols.

Power and rate control in wireless communication systems with energy harvesting and rateless codes

In this paper, for a wireless communication system with energy harvesting and rateless error correction codes, the joint optimization of transmit power, modulation scheme and code rate to maximize the long-term average achievable transmission rate under the constraint of available energy is studied. The method is given first to determine the codeword length (or code rate) for a signal-to-noise ratio (SNR) under the constraint of a pre-defined decoding error probability. Then the formula of the actual transmission rate is deduced with a specific modulation and code rate, and the optimization problem to maximize the long-term average actual transmission rate is constructed under the constraints of available harvested energy and the decoding complexity of the rateless code. Since energy harvesting and channel fading are both stochastic processes, the optimization problem is difficult to solve. By using the Lyapunov optimization framework, the original long-term optimization problem is transformed into a per time slot one. Then an efficient numerical method is proposed to obtain the solution to the problem. The proposed algorithm is verified by simulation, and the results show that the proposed algorithm can achieve a higher average actual transmission rate than the comparison algorithms aiming at optimizing the channel capacity.

Improving throughput in SWIPT-based wireless multirelay networks with relay selection and rateless codes

This paper studies a dual-hop Simultaneous Wireless Information and Power Transfer (SWIPT)-based multi-relay network with a direct link. To achieve high throughput in the network, a novel protocol is first developed, in which the network can switch between a direct transmission mode and a Single-Relay-Selection-based Cooperative Transmission (SRS-CT) mode that employs dynamic decode-and-forward relaying accomplished with Rateless Codes (RCs). Then, under this protocol, an optimization problem is formulated to jointly optimize the network operation mode and the resource allocation in the SRS-CT mode. The formulated problem is difficult to solve because not only does the noncausal Channel State Information (CSI) cause the problem to be stochastic, but also the energy state evolution at each relay is complicated by network operation mode decision and resource allocation. Assuming that noncausal CSI is available, the stochastic optimization issue is first to be addressed by solving an involved deterministic optimization problem via dynamic programming, where the complicated energy state evolution issue is addressed by a layered optimization method. Then, based on a finite-state Markov channel model and assuming that CSI statistical properties are known, the stochastic optimization problem is solved by extending the result derived for the noncausal CSI case to the causal CSI case. Finally, a myopic strategy is proposed to achieve a tradeoff between complexity and performance without the knowledge of CSI statistical properties. The simulation results verify that our proposed SRS-and-RC-based design can achieve a maximum of approximately 40% throughput gain over a simple SRS-and-RC-based baseline scheme in SWIPT-based multi-relay networks.

Online Analog Fountain Codes

Analog fountain codes (AFC) are a class of near-capacity rateless codes which have a great potential for meeting the requirements of ultra-reliable low latency communication. In this letter, an online feedback scheme is introduced to enhance error performance and achievable rate of AFC. The retransmission messages are chosen according to Euclidean distance between AFC codewords. Our simulation results show that the proposed online AFC can improve achievable rate up to 0.49 bits/symbols at 25 dB, and reduce block error rate by more than one order of magnitude.

Exploiting Rateless Codes and Cross-layer Optimization for Low-power Wide-area Networks

Long communication range and low energy consumption are the two most important design goals of Low-power Wide-area Networks (LPWANs); however, many prior works have revealed that the performance of LPWAN in practical scenarios is not satisfactory. Although there are PHY-layer and link-layer approaches proposed to improve the performance of LPWAN, they either rely heavily on the hardware modifications or suffer from low data recovery capability, especially with bursty packet loss patterns. In this article, we propose a practical system, eLoRa, for COTS devices. eLoRa utilizes rateless codes and joint decoding with multiple gateways to extend the communication range and lifetime of LoRaWAN. To further improve the performance of LoRaWAN, eLoRa optimizes parameters of the PHY-layer (e.g., spreading factor) and the link layer (e.g, block length). We implement eLoRa on COTS LoRa devices and conduct extensive experiments on an outdoor testbed to evaluate the effectiveness of eLoRa. Results show that eLoRa can effectively improve the communication range of DaRe and LoRaWAN by 43.2% and 55.7% with a packet reception ratio higher than 60%, and increase the expected lifetime of DaRe and LoRaWAN by 18.3% and 46.6%.

Analysis performance of content delivery network by used Rateless Code method

Content Delivery Network (CDN) is a server system network to content contribution in an application/web to various accessors around the world so that data sent and received by users was faster. Server selection algorithm determines the extent to which the quality of server service to client requests. This study to analyze CDN performance, used Geographical algorithm Domain Name Server (GeoDNS), Round Robin (RR), Weigthed Round Robin (WRR), dan Least Connection (LC). In addition, Rateless Code (RLC) is also applied to reduce packet loss, there are two methods used, namely the first method is rateless code 50 and the second method is rateless code 100. Thus, the trial was carried out 20 times. Besides that, it is also applied Rateless Code (RLC) to less packet loss. From the research results, the use of CDN can improve server service performance. CDN managed to reduce the maximum to the average delay about 67,6%. From the studied CDN algorithm, Geo DNS experienced the lowest delay up to about 67.6 ms, however LC experienced the lowest packet loss, namely about 2,84%. The application of rateless code on CDN with LC algorithm succeeded in reducing packet loss to about 2.84%, but delay increased to about 75.3%.

Performance enhancing of MIMO‐OFDM system utilizing different interleaving techniques with rate‐less fountain raptor code

Due to the importance of both rate-less digital fountain codes and Multi-Input Multi-Output (MIMO) schemes in Fifth and Sixth Generation (5G/6G) wireless networks, this paper investigates enhancing the performance of MIMO-Orthogonal Frequency Division Multiplexing (MIMO-OFDM) based system by employing the rate-less fountain codes. The rate-less codes, such as the Tornado codes and Raptor codes, have a flexible code rate that differs from the classical channel coding schemes. This paper uses Raptor code to study the MIMO system's performance with the rate-less codes over different wireless communications channels. The proposed MIMO-fountain code-based system has been tested over the various wireless communication channel conditions concerning the varied Frequency Doppler (FD). In the proposed rate-less wireless communication system, multiple interleaving techniques and equalizers are used to improve its performance. Computer-based simulation experiments are assigned to evaluate the MIMO-fountain code system using the different data transmission scenarios. Simulation results confirm the superiority of the presented wireless rate-less system compared to fixed-rate wireless systems in terms of Bit Error Rate (BER) and throughput.

Analysis and Design of Enhanced Distributed Fountain Codes in Multiple Access Networks with Cooperative Relay

Distributed fountain coding plays an important role in rateless code research. The reliability and effectiveness of these coding schemes are increasingly challenged with the growing applications. In this paper, a novel multiple-access network with cooperative relay is presented, and a novel enhanced distributed fountain coding scheme for this network is proposed. The overall degree distributions are derived, and the asymptotic decoding performance is analyzed theoretically by employing the And-Or tree method. On this basis, a design method using joint iterative optimization algorithms is proposed to optimize the degree distributions of the sources and relays. Simulation results show that the proposed enhanced distributed fountain codes outperform the existing generalized distributed fountain codes (GDFC) and have a good performance on both lossless and lossy channels. It reveals that the proposed codes can provide unequal error protection (UEP) property for different sources by introducing the extra cooperative relay. The performance improvement is not restricted to the sources connected to the cooperative relay but applies to all sources. With the additional relay, the proposed codes are able to overcome the effects of bad channel conditions caused by terrain, obstacles, and so on, to avoid communication interruptions and improve the reliability of the network.

Performance and time improvement of LT code-based cloud storage

Outsourcing data on cloud storage services has already attracted great attention due to the prospect of rapid data growth and storing efficiencies for customers. The coding-based cloud storage approach can offer a more reliable and faster solution with less storage space in comparison with replication-based cloud storage. LT codes are the famous member of the rateless code family that can improve performance of storage systems utilizing good degree distributions. Since degree distribution plays a key role in LT codes performance, recently introduced Poisson robust soliton distribution (PRSD) and combined Poisson robust soliton distribution (CPRSD) motivate us to investigate LT code-based cloud storage system. So, we exploit LT codes with new degree distributions to provide lower average degree and higher decoding efficiency, specifically when receiving fewer encoding symbols, compared with popular degree distribution, robust soliton distribution (RSD). In this paper, we show that proposed cloud storage outperforms traditional ones in terms of storage space and robustness encountering unavailability of encoding symbols, due to compatible properties of PRSD and CPRSD with cloud storage essence. Furthermore, a modified decoding process is presented based on required encoding symbols behavior to reduce data retrieval time. Numerical results confirm improvement of cloud storage performance.

Partial Self-Concatenation Structure and Performance Analysis of Spinal Codes Over Rayleigh Fading Channel

Spinal codes are a new family of rateless codes which have been proved to be capacity-achieving over both the additive white Gaussian noise (AWGN) channel and the binary symmetric channel (BSC). However, over the Rayleigh fading channel between the vehicle nodes, the error performance of Spinal codes is not satisfactory since the tail message blocks of Spinal codes are prone to error. To solve this issue, this paper proposes a new practical partial self-concatenation coding structure of Spinal codes, named <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N$</tex-math></inline-formula> tail-protected Spinal codes, to pointedly protect tail message blocks of Spinal codes over the flat Rayleigh fading channel. Theoretical performance analysis and simulation results are also provided to validate and verify the effectiveness of the proposed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N$</tex-math></inline-formula> tail-protected Spinal codes.

Verification-Based Decoding for Rateless Codes in the Presence of Errors and Erasures

Verification-Based Decoding for Rateless Codes in the Presence of Errors and Erasures

Self-Adaptive Ordered Statistics Decoder for Finite Block Length Raptor Codes Toward URLLC

Rateless codes can adapt to the wireless channel conditions without accurate channel state information (CSI) at the transmitter side, avoiding CSI feedback and retransmission, and thus are a promising channel coding approach to meet the stringent requirements of ultrareliable low-latency communications (uRLLCs). This article investigates a self-adaptive ordered statistics decoder (S-OSD) scheme for finite block length nonbinary Raptor code (NBRC). Aiming at minimizing the decoding complexity, some strategies for our S-OSD scheme are designed, including the segmentation rules of most reliable basis, the generating and discarding rules of test error patterns, and the stop criteria, respectively. In addition, an upper bound of block error rates (BLERs) for the NBRC under OSD is derived, which can be used to estimate the number of NBRC symbols required to successfully decode the input information via the S-OSD. Simulation results show that the complexity of our S-OSD scheme is greatly reduced comparing to the existing OSD schemes, while achieving very low BLER in the short block length regime.

LT Codes with Double Encoding Matrix Reorder Physical Layer Secure Transmission

In traditional wireless sensor networks, information transmission usually uses data encryption methods to prevent information from being stolen illegally. However, once the encryption methods are leaked, eavesdropping nodes can easily obtain information. LT codes are rateless codes; if it is attacked by random channel noise, the decoding process will change and the decoding overhead will also randomly change. When it is used for physical layer communication of wireless sensor networks, it ensures that the destination node recovers all the information without adding the key, while the eavesdropping node can only obtain part of the information to achieve wireless information security transmission. To reduce the intercept efficiency of eavesdropping nodes, a physical layer security (PLS) method of LT codes with double encoding matrix reorder (DEMR-LT codes) is proposed. This method performs two consecutive LT code concatenated encoding on the source symbol, and part of the encoding matrix is reordered according to the degree value of each column from large to small, which reduces the probability of eavesdropping nodes recovering the source information. Experimental results show that compared with other LT code PLS schemes, DEMR-LT codes only increase the decoding overhead by a small amount. However, it can effectively reduce the intercept efficiency of eavesdropping nodes and improve information transmission security.

NOMA Combined With RC for Reliable and Secure Transmission in a Delay-Constrained System

This letter proposes a Rateless codes (RC)-aided reliable and secure beam-forming scheme for a multiple input single output (MISO) delay-constrained system, combined with non-orthogonal multiple access (NOMA) technique. Total delay of the system is constraint by the number of slots (NTS) for which the source can transmit. To satisfy delay-constraint conditions, source uses NOMA to send two encoded packets in a single slot, and also exploits artificial noise (AN) for secure communication. In RC-aided communication, receiver can recover the source file when the received generator matrix is full rank. By using this characteristic of the RC, we determine the delay violation property (DVP) and the information intercept probability (IP) of the proposed system. We also determine the average number of packets that can be decoded successfully in NTS transmissions. Results show that this beam-forming technique using NOMA gives a significant rise in the number of packets decoded successfully at the legitimate receiver, leading to a more reliable and secure communication as compared to the system without using NOMA.