REFERENCE SIGNAL MANAGEMENT FOR DFT-S-OFDM WITH FDSS AND SPECTRAL EXTENSION

According to an example aspect of the present invention, there is provided an apparatus configured to select a reference signal sequence, determine a number of resource blocks located outside a frequency interval via spectrally extending the signal, and when the number is an odd number, perform exactly one of the following: symmetrically extend a cyclically shifted version of the selected reference signal sequence, or asymmetrically extend the selected reference signal sequence without shifting it, map the extended reference signal sequence to resource blocks located in the frequency interval and resource blocks located outside the frequency interval, perform spectral shaping of a second signal comprising the resource blocks located both inside and outside the frequency interval, and transmit the second signal in uplink direction.