摘要 |
A passenger aircraft video distribution system distributes modulated RF carrier signals from a central signal source (10) to be used at each passenger seat (S1, S2, S3). The carriers are modulated to contain both audio and video data (12,14) and also other digital data, such as graphics, slide shows and the like. Analog video signals (14) from the video source are modulated (100) on individually discrete carriers in the range of 54 to 300 megahertz. Audio information, including audio sound channels and the video audio, are digitized (80,84) and combined with digital data in a combined serial bit stream that is multiplexed (82), and then modulated (96) on an RF carrier having a frequency sufficiently above the frequency band of the video signals so that the resulting spectrum of the modulated audio RF carrier does not interfere with the modulated video carriers. The RF carrier signals are combined (104) and distributed to individual seats. The modulated audio carrier (112) is separated from the video carriers (110) at each seat or each group of seats and then demodulated (116) and demultiplexed (120) for selection at each individual seat of a chosen audio channel.
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