Apparatus and methods for non-systematic complex coded discrete fourier transform spread orthogonal frequency division multiplexing

A method implemented in a wireless network node for transmitting symbols using discrete Fourier transformation (DFT) spread orthogonal frequency division multiplexing (DFT-S-OFDM), the method comprising:

• mapping a first, symbol vector to inputs of a DFT-spread block using a permutation matrix that inserts zeroes into the first symbol vector corresponding to inputs of the DFT spread block to which symbols of the first symbol vector are not mapped to produce a second symbol vector;
• inserting a perturbation into the second vector to produce a third vector;
• performing a DFT on the third vector to produce a fourth vector, wherein the perturbation is configured to generate zeros on predetermined elements of the fourth vector;
• performing an inverse DFT (IDFT) operation on the fourth vector to produce an IDFT output signal;
• cancelling a tail of the IDFT output to produce a modified IDFT output signal;
• and transmitting the modified IDFT output signal.

A method implemented in a wireless network node for receiving discrete Fourier transformation (DFT) spread orthogonal frequency division multiplexing (DFT-S-OFDM) symbols, the method comprising:

• receiving the DFT-S-OFDM symbols at an antenna;
• determining a DFT of the received symbols;
• replacing symbols in the received DFT-S-OFDM symbols that correspond to predetermined elements in the DFT-S-OFDM symbols with zeros and performing an inverse DFT on the remaining received symbols;
• determining a distortion vector on the symbols in the received DFT-S-OFDM symbols that correspond to the predetermined elements;
• and
• subtracting the distortion vector from the remaining symbols.