A portable compact channel sounder system without synchronization

In this contribution a vectorial channel sounding system for narrowband MISO applications is presented. The channel is measured using a continuous wave signal allowing the characterization of time-variant channels and Doppler shifts within changing multipath propagation environments. The channel sounder's architecture with an analog-digital converter writing the measured data to a SD-card enables measurements up to several minutes with a high frequency resolution. The compact, lightweight design allows the mounting of the channel sounder on a flying octocopter platform. A typical application is the investigation of multipath propagation for navigation systems in aviation by measurements in an environment scaled with the ratio of 1:144 at frequencies in the Ku-band. Without synchronization of the carrier frequencies of the transmitter and the receiver, high flexibility is achieved. This leads to high demands on the frequency stability of their reference clocks, discussed in the contribution along with the hardware setup.