NACK-based retransmission schemes for MBMS over single frequency network in LTE
In radio resource management of Multimedia Broadcast/Multicast Service (MBMS), User Equipment (UE) feedback can be used by evolved Node B (eNB) to improve the radio spectral efficiency. As UE feedback is costly we here suggest schemes to reduce the uplink feedback while maintaining the spectral efficiency. For the 3 schemes analyzed in this paper we utilize the special characteristic of a broadcast channel, that spectral efficiency is mainly determined by the UE with lowest channel quality. The performance of the suggested schemes are evaluated with Long Term Evolution (LTE) system simulation and we conclude that using geometry for selecting feedback UEs is the optimal solution and 4 feedback UEs are enough to meet the coverage requirement.