RaptorQ Code Based Concurrent Transmissions In Dual Connectivity LTE Network

With the rapid development of telecommunication internet,a large number of mobile applications have been developed,which in return further stimulate the demand of mobile market for exponential growth of data traffic.In order to improve the transmission efficiency and single user throughput,3GPP has standardized the dual connectivity technology based on LTE/LTE-A in release 12.It attempts to increase the per-user throughput by allowing the UE to maintain connections with the MeNB(master eNB)and the SeNB(secondary eNB)simultaneously,which are inter-connected via a traditional non-ideal backhaul(X2 interface).When the user data radio bearer is split via MeNB,the UE needs to aggregate the same radio bearer and re-order to recover the source block,which leads to out-of-order packet delivery problem.As a solution,we propose to adot the RaptorQ FEC code to encode the source data at the MeNB,and then the encoded symbols are separately transmitted through the MeNB and SeNB.RaptorQ is a fountain code,which allows the receiver recovers source data from any sets of encoded source symbols.The out-of-order problem can be effectively eliminated since the UE can decode the original data as long as it receives enough encoded symbols from either the MeNB or SeNB.We present detailed protocol design for the RaptorQ code based concurrent transmission scheme,and simulation results are provided to illustrate the performance of the proposed scheme.