Vector channel-sounder using fiber delay lines to separate the channels

This paper demonstrates a technique for vector channel sounding using a single-input, single-output channel-sounder. The vector channels are separated by inserting different radio-over-fibre (RoF) signal delays into the antenna ports and then combining the antenna signals as a set of separated-in-time responses. The RoF delays must be large relative to the channel delay spreads. In the VNA/channel-sounder, the delayed channels can be easily separated with basic signal processing, ready for statistical analysis.