Throughput-Efficient Rateless Coding with Packet Length Optimization for Practical Wireless Communication Systems

Rateless coding ensures reliability for time-varying channels by providing ever-increasing redundancy at the packet level. However, the optimal packet length for rateless codes has not been carefully studied from the application layer and the physical layer. In this paper, we present a practical wireless communication system consisting of an LT coding module, a channel coding module, and error detection modules. By analyzing the system performance, we find the impacts of packet length on reliability and efficiency, and formulate the optimization problem that maximizes the throughput efficiency over time- varying channels. We also compare the performance of the rateless coding system with the conventional one which does not utilize LT codes. Simulation results show that the rateless coding system are superior to the conventional system in a large SNR range for slow channel variations and a relative small SNR range for fast channel variations.