Evaluation Framework for User Experience in 5G Systems: On Systematic Rateless-Coded Transmissions

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.