Performance analysis of a multi-code CDM transmission scheme based on cyclic extended spread code as a extension of 3rd generation CDMA system

This paper proposes an adaptive multi-code CDM transmission scheme for the multipath fading environment to achieve high code utilization efficiency. In the proposed system, we apply a new parallel transmission scheme using cyclic codes generated from a modified M-sequence which inserts the guard chips before and after an M-sequence. Moreover with radio channel estimation results obtained from the downlink by this multi-code CDM transmission scheme, the number of guard chips is varied adaptively on the uplink. In a micro cellular system, the performances of the proposed system are evaluated by computer simulation. As a result, it is essential for high quality broadband mobile communications to apply adaptive transmission to the new multi-code CDM transmission system.