OTFS - Next Generation Modulation Scheme Addressing the Challenges of 5G
In this talk I will introduce a novel modulation scheme referred to as OTFS (Orthogonal Time Frequency and Space) which is based on multiplexing information QAM symbols on localized pulses in the delay-Doppler signal representation. I will explain the mathematical foundations of this interesting representation, emphasizing how the structure establishes a conceptual link between communication and Radar theory. I will show how OTFS naturally generalizes conventional time and frequency modulations such as TDMA and OFDM. I will also discuss the unique manner in which OTFS waveforms couple with the wireless channel that allows the coherent combining of all the time and frequency diversity modes of the channel to maximize the received energy. Finally, I will explain the intrinsic potential advantages of OTFS over multicarrier modulation schemes in the context of various 5G use cases such as MU-MIMO equalization and precoding, communication under high Doppler conditions (V2X and V2V) and communication under power constraints (such as in IoT).