Multiuser Detection in Multibeam Satellite Systems: Theoretical Analysis and Practical Schemes

Abstract

We consider the rates achievable by a user in a multibeam satellite system for unicast applications, and propose alternatives to the conventional single-user symbol-by-symbol detection applied at user terminals. Singleuser detection is known to suffer from strong degradation when the terminal is located near the edge of the coverage area of a beam, and when aggressive frequency reuse is adopted. For this reason, we consider multiuser detection, and take into account the strongest interfering signal. We also analyze two additional transmission strategies requiring modifications at medium access control layer. We describe an information-theoretic framework to compare the different strategies by computing the information rate of the user in the reference beam. Furthermore, we analyze the performance of coded schemes that could approach the information-theoretic limits. We show that classical codes from the DVB-S2(X) standard are not suitable when multiuser detection is adopted, and we propose two ways to improve the performance, based on the redesign of the code and of the bit mapping. A. Modenini is with ESA-ESTEC,

Exploratory Analysis of Superposition Coding and Rate Splitting for Multibeam Satellite Systems

“…Assuming that user 1 plays the role of the weak user, the rate region achieved by SC-SCD is given by (8). First of all, both receivers jointly decode x 11 and x 12 treating the interference as noise.…”

“…Exchanging the roles of users 1 and 2, the rate region is given by (9). The overall rate region is the convex closure of the union of regions (8) and 9, namely,…”

“…From (11) and (16), we can infer that α ≤ 1. Then, under the condition (11), two cases can be differentiated in (8), namely,…”

Terrestrial Relay‐Aided Cooperative High Throughput Satellite Systems

“…Each satellite is assumed to have the perfect knowledge of its user's channel state information. The first column in (5), ie, [H T 1,1 H T 1,2 ] T , refers to the channel gains from the satellite S 1 to the users in both clusters. In particular, H T 1,1 refers to the channel gain matrix from satellite S 1 to the first cluster, and H T 1,2 refers to the channel gain matrix from satellite S 1 to the second cluster.…”

Geographical Scheduling for Multicast Precoding in Multi-Beam Satellite Systems

“…In this context, the overall system performance is strongly limited by the interference between adjacent beams. It is, thus, of paramount importance to implement advanced interference mitigation techniques at the receiver, e.g, Multi-User Detection (MUD), [5], or at the transmitter, i.e., precoding, [6]- [9].…”