Generating orthogonal time frequency division multiplexing (otfdm) waveforms with circular delay diversity in frequency domain

A method for transmitting a plurality of orthogonal time frequency division multiplexing (OTFDM) waveforms, comprising:

• generating, by a communication system, at least one data sequence and at least one reference sequence (RS);
• time-multiplexing, by a communication system, the at least one data sequence with the at least one RS, to generate a multiplexed sequence;
• transforming, by the communication system, the multiplexed sequence using a Discrete Fourier Transform (DFT) to generate a transformed sequence;
• obtaining, by the communication system, a plurality of precoded sequences from the transformed sequence, wherein each of the plurality of precoded sequences is generated by applying a distinct frequency domain phase rotation vector on the transformed sequence;
• mapping, by the communication system, each of the plurality of precoded sequences to a corresponding antenna port of the communication system to obtain a plurality of mapped sequences;
• and
• generating, by the communication system, an OTFDM waveform corresponding to each antenna port using the associated mapped sequence;
• wherein each of antenna port specific OTFDM waveform is transmitted using the corresponding antenna port.