We previously proposed an MSL-TDM (Multi-Symbol-Length Time Division Multiplexing) OFDM scheme which multiplexes symbols with different lengths for mobile and fixed reception. We have developed an OFDM experimental modem using MSL-TDM to confirm fundamental performance of MSL-TDM. This paper describes the concept of MSL-TDM, the specification of the experimental modem and some results of indoor experiments. The results show that the system works well including synchronization function, and no difference is found between the measurement results of one hierarchical transmission and two hierarchical transmission.
