Assessment of potentiality of adjacent channel interference mitigation in a low-rate TDMA system

In this paper an assessment of the effectiveness of turbo-interference cancellation (Turbo-IC) for improving the spectral efficiency of a TDMA based satellite return link channel will be addressed. Interference mitigation algorithms have been widely studied and implemented in terrestrial wireless CDMA systems. In the present paper Turbo-IC is instead adopted for reducing the carrier spacing on the satellite return channel, thus allowing to increase the system throughput for a given system bandwidth. Performance results show that throughput improvements are possible notwithstanding the higher criticality of carrier synchronization at reduced carrier spacing. It shall be noted that such an improvement in system capacity is achieved without any complexity increase at the satellite terminal (ST), as the additional signal processing required is entirely located at the gateway. Moreover, the proposed technique is fully compatible with DVB-RCS standard, which allows for applicability in current RCS VSAT systems. In the paper, extensive simulation results obtained in a realistic broadband satellite system scenario are shown and discussed.