256 QAM 400 Mb/s microwave radio system with DSP fading countermeasures

Abstract

This paper describes a 256QAM 400 Mbls system and repeater configuration, using fading countermeasures with DSP technologies. A onechip transversal filter LSI is newly developed. This LSI is used for a fully digital transversal equalizer and a cross polarization interference canceller. It offers compactness, low power consumption and no tuning. An advanced control method called the shift bit select (SBS) and the MLE method are introduced to improve control response, a q u i s i t i o n a n d s t e a d y performance. The field test confirms good performance of the fading countermeasures with DSP technologies.