Co-channel interference cancelation at the user terminal in multibeam satellite systems

Abstract

We study the applicability of soft interference cancelation in the forward link of multibeam satellite systems with\ud focus on mobile terminals. We adopt a standard currently used in commercial satellite systems as a reference. The\ud multibeam satellite antenna radiation diagram has been generated using a physical optics re¿ector model while a\ud widely adopted channel model has been used for the land mobile satellite channel. The interference pattern has\ud been derived using a system simulator developed by the European Space Agency. Starting from the analysis of\ud the interference pattern, we study the application of a low-complexity soft interference cancelation scheme for\ud commercial applications. Our results show that, under realistic conditions, a two-colors frequency reuse scheme\ud can be employed while guaranteeing service availability across the coverage and keeping the complexity at the\ud user terminals relatively low.Peer ReviewedPostprint (author's final draft

Symbol-Asynchronous Transmission in Multibeam Satellite User Down-Link: Rate Regions for Novel Superposition Coding Schemes

“…Let 1 and 2 denote a pair of beams that simultaneously serves users 1 and 2. Beam 1 sends √ λ1s (1) + λ 1s (2) and beam 2 sends √ λ2s (3) + λ 2s (4) . Here,λi is a short-hand notation for (1 − λi), λ1 and λ2 are design parameters that take values in [0, 1), and s (j) ∈ C N ×1 , j = 1, 2, 3, 4, denote coded symbol sequences of size N with components s (j) [k] that are normalized to unit enery, i.e., E s (j) [k] 2 = 1.…”

“…3). For SC-SCD: -Tx: The information for one user is encoded in s (1) , s (3) , the information for the other user is encoded in s (2) , s (4) .…”

“…Assuming synchronous waveform reception and convenient user pairing, the potential of these schemes has been demonstrated [1]. However, with expected interbeam differential delays in the order of a few nanoseconds and tentative baud rates up to 1 Tbps [10], SC-SCD z = (s (1) ,s (3) ) z = void switch open switch closed (2) ,s (4) ) z y β w β (s (1) ,s (2) ) (s (3) ,s (4) )…”

“…3. Summary of SCD strategies at UTs β = 1, 2 in SC-SCD and NCRS when s (2) , s (4) is allocated to user i = 1, 2.…”

Precoding, Scheduling, and Link Adaptation in Mobile Interactive Multibeam Satellite Systems

“…While the latter approach increases the UT complexity, precoding requires the use of resources for feeding back the channel state information (CSI) and additional complexity at the Gateway (GW), which, however, has limited impact on the overall system from an operator perspective. Considering the high gains that precoding obtains in fixed satellite services [2]- [5] compared to the limited gains obtained with multiuser detection in mobile systems [6], [7] and attending to the pursued low cost UT in mobile systems, we focus on the precoding approach.…”