Rateless transmission of polar codes with information unequal error protection

In this study, a rateless transmission scheme with information unequal error protection (UEP) is proposed by using polar codes. The proposed scheme is suitable for transmissions in time-varying channels, as well as pursues UEP goal of information with different reliability requirements. Firstly, the authors design rateless transmission for an unknown channel via extending polarisation matrix and importance-based puncturing. In particular, an algorithm ensuring full coding gain for UEP performance is proposed on the basis of rateless transmission. Moreover, in consideration of combining flexible successive cancellation list (SCL) decoding with UEP, they further present a size-adapted SCL decoding scheme with reduced complexity. Numerical simulation shows that their proposed rateless scheme based on polar codes could achieve good UEP performance with low complexity in unknown channels.