TH-sequence construction for centralised UWB-IR systems in dispersive channels

A novel time hopping sequence construction algorithm is proposed for centralised impulse radio systems. The proposed multiple accessing method takes into account the number of active users in the system and maximum excess delay of the channel. By carefully grouping the time hopping sequences, orthogonality of the codes are preserved, despite multipath up to a certain number of users. For a larger number of users, the proposed code construction minimises the overall performance degradation.