High-Capacity, Weather-Resilient MIMO Feeder Links in Multibeam Satellite Systems

Next-generation satellite systems targeting multi-Terabit-per-second throughput require surmounting layers of design challenges. For feeder links, extremely high frequency (EHF) band is desired to overcome spectrum limitations and reduce equipment size. Multiple gateways are utilized to aggregate their bandwidths and serve as site diversity, mitigating the increased susceptibility of the EHF band to atmospheric attenuation. Toward this, multiple-input multiple-output (MIMO) technology is well suited for feeder links that share the same time, frequency, and polarization resources. This paper provides novel extension of MIMO-enabled feeder links when clustering more than two gateways and mounting more than two antennas onboard geostationary multibeam satellite, exploiting line-of-sight MIMO on uplinks and downlinks. Arsenal of countermeasures against inter-antenna interference and weather impairments is designed to maximize gains in signal-to-noise ratio, spatial multiplexing, and spatial diversity. Comparisons between offered sum rates and theoretical MIMO capacity are provided when gateway clusters form linear versus circular patterns. Methodology for gateway diversity is developed and analyzed when deploying redundant MIMO feeder links that handle rerouted traffic. Algorithms for ground-based channel state information (CSI) acquisition are designed and implemented in receiver architecture that tackles strong practical impairments. Numerical studies reveal that MIMO-enabled feeder links offer greatly enhanced overall network availability compared with state-of-the-art single-input single-output (SISO) solutions.