Uplink reference signal design for LTE compatible GEO multiple-beam mobile satellite communication system

For 3GPP long term evolution (LTE) uplink, reference signal (RS) is an important kind of physical signal which is primarily used for demodulation and channel sounding. However, in the multiple-beam satellite environments, the inter-beam and intra-beam interference will break the orthogonality of uplink RS (UL-RS) from different user equipments (UEs), resulting in system performance degradation. In this paper, according to the characteristics of the satellite channels and inter/intra-beam interference, we analyze the compatibility problem, calculate the available capacity for the existing UL-RS in multiple-beam satellite environment, and propose a novel uplink RS scheme which includes UL-RS sparsing, OCC scrambling and resource configuration for LTE compatible GEO multiple-beam mobile satellite communication system. Simulation results prove the effectiveness of the proposed UL-RS scheme.