Method for processing transmitted and reflected signals for removing unwanted signals and noise form wanted signals.

In an identification system based on reflections of radar signals from a bit-coded transponder, the received signals are processed to remove unwanted signals and noise from the required, reflected and received signals that have a recurrent, equal cycle. The reflected signals are extremely weak in relation to the unwanted signals and noise. A transmitter unit (11) and a time slot device (15) form through a random bit sequence (14) phase modulated pulse trains which are transmitted. These are reflected from a coded passive transponder (12) back to a receiver (13) which leads the demodulated signal into an integrator array (16) that is controlled by said bit sequence (14) together with the time slot signal from a device (15). The inverted signal is also utilized. The synchronization is being performed through shift registers (19) which together with the bit sequence control the integrator array (16).