System for flexible cyclic prefix length for preamble symbols in an OFDM based communication system

摘要

A system providing flexible cyclic prefix length in a preamble (i.e., superframe preamble) is disclosed. The preamble comprises a first section and a second section. The first section contains at least one broadcast channel and occupies the first number of OFDM symbols in the preamble. The second section contains acquisition pilots and occupies the remaining number of OFDM symbols in the preamble. A first cyclic prefix length is used in the first section. It is indicated by the first broadcast channel and is unknown to a mobile station before the mobile station decodes the first broadcast channel. The second cyclic prefix length is used in the second section. It is fixed and known to the mobile stations. The first broadcast channel is located at the last OFDM symbol in the first section and is next to the second section in time.