  Current State-of-the-Art High Throughput Satellite systems provide wide-area
connectivity through multi-beam architectures. Due to the tremendous system
throughput requirements that next generation Satellite Communications (SatCom)
expect to achieve, traditional 4-colour frequency reuse schemes are not
sufficient anymore and more aggressive solutions as full frequency reuse are
being considered for multi-beam SatCom. These approaches require advanced
interference management techniques to cope with the significantly increased
inter-beam interference both at the transmitter, e.g., precoding, and at the
receiver, e.g., Multi User Detection (MUD). With respect to the former, several
peculiar challenges arise when designed for SatCom systems. In particular,
multiple users are multiplexed in the same transmission radio frame, thus
imposing to consider multiple channel matrices when computing the precoding
coefficients. In previous works, the main focus has been on the users'
clustering and precoding design. However, even though achieving significant
throughput gains, no analysis has been performed on the impact of the system
scheduling algorithm on multicast precoding, which is typically assumed random.
In this paper, we focus on this aspect by showing that, although the overall
system performance is improved, a random scheduler does not properly tackle
specific scenarios in which the precoding algorithm can poorly perform. Based
on these considerations, we design a Geographical Scheduling Algorithm (GSA)
aimed at improving the precoding performance in these critical scenarios and,
consequently, the performance at system level as well. Through extensive
numerical simulations, we show that the proposed GSA provides a significant
performance improvement with respect to the legacy random scheduling.
