Practical retransmission schemes using network coding for 4G multicast/broadcast services

In this work we design retransmission schemes for broadcast networks using simple network coding techniques. In particular we study a wireless system with limited uplink feedback which can either be shared among all users or be partitioned for dedicated usage. In the shared feedback model the number of transmission errors is estimated using a voice-vote mechanism; the feedback needed is independent of the number of users. In the dedicated feedback model we consider varying levels of uplink feedback: none, partial and perfect. We design efficient retransmission schemes according to the feedback model and available bandwidth. Numerical results showing performance benefits are presented.