The invention concerns a system for determining the position of mobile element relative to a stationary structure, the system comprising an encoder configured to emit a pseudo-sinusoidal spatial signal representing the position of the encoder, a sensor (2) comprising a current-loop mount between at least two resistive elements (3) and a signal processing device Vi configured to supply two quadrature signals respectively SIN and COS of same amplitude. The invention also concerns an antifriction bearing equipped with such a system for determining the angular position of the rotating ring relative to the stationary ring.