Characteristics of a High Capacity 16 QAM Digital Radio System in Multipath Fading

Multipath fading effects on a 200 Mbit/s 16 QAM digital radio system have been experimentally investigated. It was found that the outage probability can be accurately estimated using only the in-band frequency response without knowledge of the delay difference between two incident waves. New methods to evaluate the improvement factors for both space diversity reception and dynamic equalizing, which are required to combat multipath fading effects, were also proposed. In particular, the significance of noticing the delay dispersion sign was pointed out when attaining sufficient equalization effect. The validity of these evaluations was confirmed by simulation experiments and a field trial.