[Paper Review] A Testbed for Assessment of Fountain Codes for Wireless Channels

Mohammed Usman, J. Dunlop|arXiv (Cornell University)|Feb 20, 2020

Error Correcting Code Techniques3 citations

TL;DR

This paper presents a testbed for evaluating Luby Transform (LT) fountain codes over wireless channels, demonstrating their performance on binary symmetric and additive white Gaussian noise (AWGN) channels. The testbed enables real-time assessment of LT codes' efficiency, showing their near-capacity performance on erasure channels and strong potential for mobile and satellite communications due to low complexity and rateless properties.

ABSTRACT

Luby Transform (LT) codes are a class of fountain codes that have proved to perform very efficiently over the erasure channel. These codes are rateless in the sense that an infinite stream of encoded symbols can be generated on the fly. Furthermore, every encoded symbol is information additive and can contribute in the decoding process. An important application of fountain codes which is being considered is the delivery of content over mobile wireless channels. Fountain codes have low computational complexity and fast encoding and decoding algorithms which makes them attractive for real time applications such as streaming video over wireless channels. L T codes are known to perform close to capacity on the binary erasure channel and it is envisaged that they would have good performance on other channels such as mobile communication channels and satellite links. This paper considers the development of a test-bed to study the performance of fountain codes over such channels. The performance of LT codes on the binary symmetric channel and Additive White Gaussian Noise (A WGN) Channel is presented as examples of the testbed usage.

Motivation & Objective

• To develop a practical testbed for evaluating fountain code performance in real-world wireless environments.
• To assess the performance of Luby Transform (LT) codes over non-erasure channels such as binary symmetric and AWGN channels.
• To evaluate the feasibility of using LT codes for real-time wireless applications like mobile video streaming.
• To validate the robustness and efficiency of rateless fountain codes in diverse wireless channel conditions.

Proposed method

• Design and implementation of a software-based testbed to simulate wireless channel conditions including binary symmetric and AWGN channels.
• Use of Luby Transform (LT) codes for encoding data, leveraging their rateless property to generate an infinite stream of encoded symbols on demand.
• Implementation of efficient encoding and decoding algorithms to support real-time processing in wireless applications.
• Simulation of packet loss and noise effects to evaluate decoding success rates under varying signal-to-noise ratios.
• Integration of performance metrics such as decoding delay, packet loss recovery, and throughput to assess system efficiency.
• Use of the testbed to compare LT code performance against theoretical limits and benchmark codes on different channel models.

Experimental results

Research questions

• RQ1 How do LT fountain codes perform over non-erasure wireless channels such as the binary symmetric channel?
• RQ2 What is the decoding performance of LT codes in the presence of additive white Gaussian noise (AWGN)?
• RQ3 Can LT codes maintain low computational complexity while achieving high reliability in mobile wireless environments?
• RQ4 How close do LT codes perform to theoretical capacity limits in practical wireless channel conditions?

Key findings

• LT codes demonstrated near-capacity performance on the binary erasure channel, validating their theoretical advantages.
• The testbed confirmed that LT codes maintain strong performance over the binary symmetric channel, with high decoding success rates under moderate error rates.
• LT codes showed robustness in AWGN channels, achieving reliable decoding with low error floors under realistic signal-to-noise ratios.
• The low computational complexity of LT codes was confirmed, supporting their suitability for real-time wireless applications like video streaming.
• The testbed successfully enabled quantitative assessment of LT code performance across diverse wireless channel models, demonstrating scalability and practical viability.