A Look at OTFS from a Hybrid Carrier Perspective

The Orthogonal Time Frequency Space Modulation (OTFS) is an attractive waveform proposed recently because of its enormous potential for the widespread applications in the future communication networks. Most of the efforts for OTFS studies focusing on its superiorities over the Orthogonal Frequency Division Multiplexing (OFDM) which is accepted as a typical multi-carrier (MC) waveform. OTFS itself has also been seen as a special MC scheme, although it was thought to be a bridge between OFDM and its single carrier (SC) counterpart when OTFS was first proposed. In this paper, we describe this system afresh to reveal its essential characteristic as a hybrid single and multi-carrier scheme. From this perspective, many properties of OTFS could be understood apparently, and the evolution path of OTFS might be foreseen.