Possible effects of spread-spectrum-clock interference on wideband radiocommunication services

The possible effects of spread-spectrum-clock interference on wideband radiocommunication services have been investigated in relation to the interference that would be caused by unmodulated clock signals. The study includes radio systems like digital video broadcast terrestrial (DVB-T) and wideband CDMA (W-CDMA) mobile radiocommunication. The results of the investigation show that the increase of the interference effect by FM modulation on the clock signals is significant As the present emission test methods do not correlate with the effect, the CISPR may have to find a solution which is not covered by the present test methods, e.g. by using the radio system bandwidth as measurement bandwidth