Blind two-step synchronization for direct-sequence UWB systems

In this paper, a blind two-step synchronization algorithm is proposed for direct-sequence (DS) ultra-wideband (UWB) communication systems. In the first step, the start of individual frames is estimated via simple square, overlap-add operation and energy detection technique. Then the first frame in each symbol is identified by exploiting the randomicity of DS codes and information symbols at the second step. Achieving synchronization with pulse-level resolution, the proposed algorithm considerably reduces synchronization time and complexity due to the two-step synchronization structure, compared with the single-step algorithm. Simulations and comparisons confirm that the proposed approach outperforms the existing alternative in terms of normalized mean square error (NMSE) and bit error rate (BER).