Feasibility of Spectrum Sharing Between Fixed and Mobile Radio Systems

General techniques are presented to investigate the feasibility of spectrum sharing between a DS-CDMA mobile radio system and a fixed point-to-point microwave link. The limitations of a spectrum sharing arrangement are identified for specific system parameters. Initial results indicate that, for the systems considered, spectrum sharing will be difficult to implement in many environments and that the spectrum sharing arrangement is limited by the mobile radio system performance, in particular the reverse mobile link. However it is shown that the coordination requirements of the two systems converge when the mobile transmission power is increased. When excision suppression is used to remove fixed service interference at a mobile receiver, it may have an adverse effect on the mobile system performance due to a degradation in the correlation characteristics of the received signal. The degradation in the received signal depends on the width and centre frequency of the excised interference relative to the mobile signal.