Hierarchical Modulation Satellite Terrestrial Signal Combining

The patent combines hierarchical modulation systems from both satellite and terrestrial sources into a unified system. The satellite receiver and terrestrial receiver are merged to process and combine signals from both sources, allowing the system to adapt to varying reception conditions by selecting or combining signals based on availability and quality.

The unified hierarchical modulation system serves multiple functions: it can operate with satellite signals alone, terrestrial signals alone, or both simultaneously. The system adapts to different reception scenarios (obstructed satellite reception, obstructed terrestrial reception, or clear line-of-sight) by activating appropriate signal paths and combining methods.

The receiver is segmented into distinct functional modules: a satellite signal processing path with satellite demodulator and hierarchical decoder, and a terrestrial signal processing path with terrestrial demodulator and hierarchical decoder. Each path independently processes its source signals through separate forward error correction decoders, allowing parallel operation and reducing the complexity burden on any single component.

The hierarchical modulation structure embeds a robust inner stream within a higher-rate outer stream. The inner hierarchical stream uses more robust modulation and coding, while the outer stream carries additional data. This nested structure allows receivers to decode at least the inner stream under poor conditions, providing layered reliability.