Patent ID: 8526540
Filing Date: 2013-09-03
Classification: H04B

Abstract:
1. A method comprising: receiving a radio signal comprising at least one data symbol, the at least one data symbol allocated at a transmit side one or more pseudo-noise (PN) sequences, the one or more PN sequences being offset quadrature phase shift keying (QPSK) modulated; converting the received radio signal into a complex baseband signal sampled in the chip clock; generating a demodulated signal by differential demodulation of the complex baseband signal sampled in the chip clock; providing one or more derived sequences, each derived sequence being assigned a particular PN sequence of the one or more PN sequences and including at least one derived chip with a positive index; for each of the one or more derived sequences, correlating the demodulated signal with a number of derived chips in the derived sequence, the number of derived chips being lower by one than a number of PN chips contained in the PN sequence that is assigned to the derived sequence; calculating measuring conformity of the demodulated signal to each of the one or more derived sequences that are correlated with the demodulated signal; and evaluating the correlation results to derive the values of the at least one data symbol using a selected one of the one or more derived sequences with a highest degree of conformity to the demodulated signal.