A method and device is provided for detecting data symbols in a received radio signal. Each data symbol is allocated transmit-side a symbol value-specific PN sequence of successive PN chips in the chip clock, and the allocated PN sequences are offset QPSK modulated. The method for incoherent detection includes 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, calculating correlation results by correlating the demodulated signal with the derived sequences, and deriving the values of the data symbols by evaluating the correlation results. Each derived sequence is assigned to a PN sequence allocable transmit-side and includes derived chips, whose values correspond to a logic linking of particular PN chips of the PN sequence allocable transmit-side that is assigned the derived sequence. The invention relates furthermore to a corresponding receiving unit.