부산대학교 도서관

This paper proposes a new parallel transmission scheme using cyclic codes generated from a modified M-sequence, which is biased with constant direct current (dc) on a M-sequence and inserted guard chips before and after this biased M-sequence. In the proposed system, the orthogonality of codes is kept not only between parallel transmission channels but also between direct and delayed waves within the guard chips. In this paper we apply a code and chip timing joint recovery scheme based on the feature of the guard chips of a modified M-sequence and evaluate the bit error rate performances by computer simulations. As a result, the proposed system can transmit several Mbps with better quality in comparison with conventional multi-code code division multiplexing (CDM) transmission.