Signalling of modulation type in adatpive modulation systems

摘要

The present invention relates to an adaptive modulation transmission system and solves the problem to realise self-consistent bursts, that is bursts transporting inside also the information concerning the type of modulation used to code data, limiting the additional overhead and adequately protecting the above mentioned information. Associating a particular sequence of symbols, to be used as a preamble, to each modulation and selecting sequences at appropriate decision distance, it is possible to assign to the preamble the modulation identification function in addition to the customary synchronisation and channel estimate functions. The preamble thus obtained maintains auto-correlation properties suitable to the burst synchronisation (Fig. 1).