In this paper we investigate the effectiveness of iterative (turbo) synchronization at improving the link reliability of digital video broadcasting return channel via satellite (DVB-RCS) for different modulation schemes in the presence of strong phase noise. We also propose a multi-user scheme that enables two remote terminals, each using QPSK, to simultaneously use the same frequency band. All additional complexity is located at the central hub receiver, while remote terminals use traditional DVB-RCS transceivers. The new scheme achieves the same system throughput as a single-user with 16APSK, thought of for second generation DVB-RCS (DVB-RCS 2), but with existing DVB-RCS remote terminals, and can be used with future DVB-RCS 2 systems to provide more scheduling flexibility.