LINK ADAPTER INTERFACE FOR UPGRADING EXISTING SATELLITE COMMUNICATION SYSTEM FOR ENHANCED MODULATION AND CODING

摘要

The standard BPSK modulation and encoding mechanism employed by the head end of a satellite-linked DATS communication sytem (10) are replaced with digital video broadcast standard QPSK modulation (41) and Viterbi/Reed-Solomon error correction encoding that are effective to provide significantly improved link performance. Each downlinked receiver site is retrofitted with a front end link adapter interface (40) that is operative to demodulate the link-efficient, replacement modulation and coding to baseband, and then convert the demodulated and MPEG-based packetized baseband signals (42) into an original TDM aggregate baseband signal which is then remodulated and encoded (43) into the communication protocol used by the existing non-upgraded receiver, so that the in-place receiver may demodulate the signal.