A low-complexity time of arrival (TOA) estimation method for Transmitted Reference Ultra-wideband (TR-UWB) signals is proposed. It has a two-step structure adapted to the Time Delayed Sampling and Correlation (TDSC) receiver. The estimation principle is based on the changes of the received signal by means of the derivative of its sliding correlation. The first step of the proposal finds a signal block containing the start of the direct path received pulse (coarse estimate). The second step searches in that block for the actual beginning of the pulse with a higher resolution (fine estimate). The method takes into account the characteristics of the TDSC receiver CMOS prototype which in its actually version can achieve a sampling frequency of 7.5 GHz letting obtain a resolution of around 4 cm. The performance evaluation of the proposed TOA estimation is presented along with some experimental results. This TOA estimator structure is simple, feasible and with a low computing demand, suited for fast mobile localization