The problem of code acquisition for the Galileo system is investigated in this paper. The effect of non-ideal sampling on the binary offset carrier (BOC) modulated signal is evaluated and a novel detection scheme, identified as Quadribranch, is proposed. Detection performance is investigated by analysis and simulations taking into account frequency errors and non ideal sampling with actual Galileo signals. The notable result is that Quadribranch is able to improve performance in terms of detection probability and mean acquisition time, and, differently from the conventional approach, allows to achieve robust code acquisition without oversampling.