A set of formats and protocols is proposed for a satellite communications system. In these formats, a pilot signal (PS) is inserted after every 25 or 29 data symbols. The formats consist of SCPC frames (F) which may contain either data (D) and in-band signalling information (SU), or only signalling information...http://www.google.com/patents/US6665361?utm_source=gb-gplus-sharePatent US6665361 - Communication method and apparatus
