Timing synchronization is a critical challenge in ultra-wideband impulse radios (UWB-IRs). Conventional fulldigital synchronization methods encounter implementation difficulties such as high rate sampling and complex RAKE structures. To avoid these challenges, we propose a code-assisted blind synchronization (CABS) algorithm which can also be implemented in a semi-analog method. CABS algorithm relies on the discriminative nature of both the time hopping code and a well-designed polarity code, and the challenging channel estimation can be bypassed during the synchronization phase. In the proposed implementation, the algorithm only requires symbol-rate sampling. The performance of CABS is evaluated, both analytically and numerically, and a data-aided variant of the algorithm is also proposed.