The Hybrid Transmission Scheme of a 900 MHz Digital Land Mobile Radio System

The hybrid transmission scheme of MATS-D uses different transmission principles on both directions of a duplex radio link. Based on the analysis of the radio transmission characteristics and of multiple-access methods, the two directions are designed independently from each other. In the downlink (from base station to mobile station) a combination of TDM and CDM is applied. In the uplink (from mobile station to base station) single channel per carrier FDMA with generalized tamed frequency modulation (GTFM) is employed. Both transmission schemes have been implemented. Measurements with fading generators as well as field tests were carried out. Experimental results are presented for the performance of both transmission schemes, expressed in terms of the bit error rate versus the signal-to-noise ratio and the signal-to-interference ratio.