Fountain codes are typically defined solely based on the right degree distributions which are Soliton or Soliton-like in most cases. In this paper, we consider Fountain encoders for the Gaussian channel and improve their performance by shaping the resulting left degree distributions away from Poisson. The proposed Fountain encoders achieve lower left degree variance at the same average degree. This in turn improves the growth of the so-called ripple in the BP decoding. The new encoders outperform the traditional ones in terms of overhead, error rate, and decoding complexity.

Improved systematic fountain codes in AWGN channel

We focus on the design of distributed Luby transform (DLT) codes for erasure networks with multiple sources and multiple relays, communicating to a single destination. The erasure-floor performance ...

/pdf/buffer-based-distributed-lt-codes-3sdvjue6th.pdf

Buffer-Based Distributed LT Codes

In this paper, we aim to find a robust network formation strategy that can adaptively evolve the network topology against network dynamics in a distributed manner. We consider a network coding deployed wireless ad hoc network where source nodes are connected to terminal nodes with the help of intermediate nodes. We show that mixing operations in network coding can induce packet anonymity that allows the inter-connections in a network to be decoupled. This enables each intermediate node to consider complex network inter-connections as a node-environment interaction such that the Markov decision process (MDP) can be employed at each intermediate node. The optimal policy that can be obtained by solving the MDP provides each node with the optimal amount of changes in transmission range given network dynamics (e.g., the number of nodes in the range and channel condition). Hence, the network can be adaptively and optimally evolved by responding to the network dynamics. The proposed strategy is used to maximize long-term utility, which is achieved by considering both current network conditions and future network dynamics. We define the utility of an action to include network throughput gain and the cost of transmission power. We show that the resulting network of the proposed strategy eventually converges to stationary networks, which maintain the states of the nodes. Moreover, we propose to determine initial transmission ranges and initial network topology that can expedite the convergence of the proposed algorithm. Our simulation results confirm that the proposed strategy builds a network which adaptively changes its topology in the presence of network dynamics. Moreover, the proposed strategy outperforms existing strategies in terms of system goodput and successful connectivity ratio.

Network Coding Based Evolutionary Network Formation for Dynamic Wireless Networks

Drone advancements have ushered in new trends and possibilities in a variety of sectors, particularly for small-sized drones. Drones provide navigational interlocation services, which are made possible by the Internet of Things (IoT). Drone networks, on the other hand, are subject to privacy and security risks due to design flaws. To achieve the desired performance, it is necessary to create a protected network. The goal of the current study is to look at recent privacy and security concerns influencing the network of drones (NoD). The current research emphasizes the importance of a security-empowered drone network to prevent interception and intrusion. A hybrid ML technique of logistic regression and random forest is used for the purpose of classification of data instances for maximal efficacy. By incorporating sophisticated artificial-intelligence-inspired techniques into the framework of a NoD, the proposed technique mitigates cybersecurity vulnerabilities while making the NoD protected and secure. For validation purposes, the suggested technique is tested against a challenging dataset, registering enhanced performance results in terms of temporal efficacy (34.56 s), statistical measures (precision (97.68%), accuracy (98.58%), recall (98.59%), F-measure (99.01%), reliability (94.69%), and stability (0.73).

https://www.mdpi.com/1424-8220/22/7/2630/pdf?version=1648633208

Smart Cybersecurity Framework for IoT-Empowered Drones: Machine Learning Perspective

Error-prone patterns have been extensively studied for low-density parity-check codes yet they have never been fully explored for generator-based ‘Fountain codes’. It is shown here that these phenomena are related to certain combinatorial structures within the Tanner graph (TG) representation of the code, previously termed absorbing sets. The authors systematically define the ‘absorbing sets’ in the generator-based TG of a code. They then demonstrate how these substructures are damaging to the ‘realised rate, delay’ and ‘decoding cost’ of Fountain codes particularly at low error rates. They further analyse the existence probability of certain absorbing sets and propose a new encoder/decoder pair forming a new family of Fountain codes. The authors experimental results show that these new codecs lead to improvements in all system features. Typical gains for Luby-transform codes include 20% reduction in the decoding complexity and simultaneous coding gains of 0.6 and 0.9 dB at bit error rates of 10 − 5 and 10 − 6, respectively. As such, this work takes a step towards better rateless code design and construction.

Analysis and design of a new fountain codec under belief propagation

In this paper, we investigate the performance analysis of the IEEE 802.11 DCF protocol at the data link layer. We analyze the impact of network coding in saturated and non-saturated traffic conditions. The cross-layer analytical framework is presented in analyzing the performance of the encode-and-forward (EF) relaying wireless networks. This situation is employed at the physical layer under the conditions of non-saturated traffic and finite-length queue at the data link layer. First, a model of a two-hop EF relaying wireless channel is proposed as an equivalent extend multi-dimensional Markovian state transition model in queuing analysis. Then, the performance in terms of queuing delay, throughput and packet loss rate are derived. We provide closed-form expressions for the delay and throughput of two-hop unbalanced bidirectional traffic cases both with and without network coding. We consider the buffers on nodes are unsaturated. The analytical results are mainly derived by solving queuing systems for the buffer behavior at the relay node. To overcome the hidden node problem in multi hop wireless networks, we develop a useful mathematical model. Both models have been evaluated through simulations and simulation results show good agreement with the analytical results.

Performance Analysis of Network Coding Based Two-Way Relay Wireless Networks Deploying IEEE 802.11

Although error-prone patterns have been extensively studied for low-density parity-check (LDPC) codes, to the best of our knowledge, they have never been fully explored for Fountain codes. It is shown that dominant trapping sets of Fountain codes are the absorbing sets. They happen in the so-called error floor, corresponding to a significant flattening in the error probability curves. In this paper, we introduce the properties of these dominant trapping sets for Fountain codes. This definition of absorbing sets leads to better design of practical finite-length Fountain encoders and decoders.

Absorbing sets of Fountain codes over noisy channels

This paper addresses throughput and delay gains resulting from network coding (NC) used to complement multi-packet reception (MPR) in a single-relay multi-user wireless network in saturated and non-saturated traffic conditions. The cross-layer analytical framework is presented in analyzing the performance of the encode-and-forward (EF) relaying wireless networks, where employed at the physical layer under the conditions of unsaturated traffic and finite-length queue at the data link layer. Considering the characteristics of EF relaying protocol at the physical layer, first a model of a two-hop EF relaying wireless channel is proposed as an equivalent extended multi-dimensional Markovian state transition model in queuing analysis. We show that the initial transmissions and the back-filling process can be greatly sped up through a combination of NC and MPR. We provided closed-form expressions for two-hop unbalanced bidirectional traffic cases both with and without NC even if the buffers on nodes are unsaturated. The analytical results are mainly derived by solving queuing systems for the buffer behavior at the relay node. The model has been evaluated through simulations and in comparison with the existing analytical model. Simulation results show good agreement with the analytical results.

Effect of Network Coding and Multi-packet Reception on Point-to-Multi-point Broadcast Networks

Abstract It is predicted that the use of unmanned aerial vehicles (UAVs) in communication systems will be more extensive in future generations of wireless telecommunication networks, due to their facilitating advantages. In this paper, a UAV-based wireless communication system is considered in which a UAV is employed as a relay to connect two ground users. These two disconnected users make a communication pair. Our aim is to maximize the minimum achievable information rate for the communication link between the transmitter and receiver, by cooperatively optimizing UAV trajectory and transmitter and source power allocation. Motivated by the above, we formulate the optimization problem. The solving process is complicated because of the non-convexity of the formulated problem. To overcome this difficulty, we convert the main problem to some sub-problems by fixing some constraints and solving them with iterative algorithms such as successive convex optimization and reaching the solution for the main problem. Simulation results show the capability of the proposed algorithm. 

/pdf/toward-uav-based-communication-improving-throughput-by-1aedqlv9.pdf

Seyed Masoud Mirrezaei

Papers

Performance Analysis of Network Coding Based Two-Way Relay Wireless Networks Deploying IEEE 802.11

Absorbing sets of Fountain codes over noisy channels

Effect of Network Coding and Multi-packet Reception on Point-to-Multi-point Broadcast Networks

Analysis and design of a new fountain codec under belief propagation

Toward UAV-based communication: improving throughput by optimum trajectory and power allocation