FDM based MIMO spatio-temporal channel sounder

In this paper, implementation of a multi-input multi-output (MIMO) channel sounder is considered, taking hardware cost and realtime measurement into account. A MIMO sounder needs some kind of multiplexing to distinguish between transmitting antennas. We compared three types of multiplexing, i.e. TDM, FDM, and CDM, for the sounding purpose in terms of realtime measurement, hardware cost, and major drawbacks. Then we chose a FDM based technique to achieve cost effectiveness and realtime measurement. In the framework of FDM, we proposed an algorithm to solve drawbacks and to estimate MIMO channel parameters. Furthermore the proposed algorithm was implemented into hardware, and validity of the proposed algorithm was evaluated through measurements in an anechoic chamber.