The feasibility of spectrum sharing between DS-CDMA mobile radio systems and microwave point-to-point links

Radio spectrum allocated for many second and third generation mobile radio systems in the 1-3 GHz frequency bands (e.g. USA PCS, DCS1800 and FPLMTS) is currently used in many countries for fixed point-to-point microwave links. General techniques are presented to investigate the feasibility of spectrum sharing between an indoor DS-CDMA mobile radio system with vertical frequency reuse and a fixed point-to-point microwave link. Using a range of system parameters, the limitations of spectrum sharing are estimated. The results indicate that, for the systems considered, spectrum sharing will be difficult to implement without sufficient geographical isolation between the two systems. It is also apparent that the feasibility of spectrum sharing depends largely on the propagation characteristics between the two systems. The feasibility of spectrum sharing depends on the mutual and self-interference that will be received in the fixed and mobile systems. General techniques for characterising this interference and determining the feasibility of spectrum sharing are outlined.