A platform with a signal generation unit and a transmitting unit. The signal generation unit is adapted to generate a spreading code sequence. The spreading code sequence has a reference chip with a rising edge and a falling edge. The signal generation unit is adapted to adjust the spreading code sequence to ensure that the rising edge or the falling edge of the reference chip arrives at a Virtual Timing Reference Station, VTRS, on a predetermined time (tref,VTRS). The transmitting unit is adapted to engage with the signal generation unit and adapted to transmit the spreading code sequence. Further, a user device for receiving the transmitted spreading code sequence.