Method and receiving unit for the detection of data symbols

A receiving unit comprising:

• an antenna configured to receive 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;
• and
• one or more processors coupled to the antenna and configured to:
• convert the received radio signal into a complex baseband signal sampled in a chip clock;
• generate a demodulated signal by differential demodulation of the complex baseband signal sampled in the chip clock;
• provide one or more derived sequences, each derived sequence assigned to a particular PN sequence of the one or more PN sequences and including at least one derived chip with a first positive index;
• for each of the one or more derived sequences, correlate 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;
• calculate correlation results measuring conformity of the demodulated signal to each of the one or more derived sequences that are correlated with the demodulated signal;
• and
• evaluate 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.

A receiving unit comprising:

• one or more processors in communication with the antenna, the one or more processors comprising:
• an internal receiver configured to:
• receive via one or more antennae 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 offset quadrature phase shift keying (QPSK) modulated;
• and
• convert the received radio signal into a complex baseband signal sampled in a chip clock;
• a differential demodulator configured to generate a demodulated signal by differential demodulation of the complex baseband signal sampled in the chip clock;
• a sequence providing unit configured to provide one or more derived sequences, each derived sequence assigned to a particular PN sequence of the one or more PN sequences and including at least one derived chip with a first positive index;
• a correlation unit configured to:
• for each of the one or more derived sequences, correlate 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;
• calculate correlation results measuring conformity of the demodulated signal to each of the one or more derived sequences that are correlated with the demodulated signal;
• and
• an evaluation unit configured 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 determined by evaluating the correlation results.