Systems, methods, apparatuses, and computer program products relating to phase tracking reference signal (PT-RS) design, for example, for discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM), are provided. One method may include forming, by a network node, a phase tracking reference signal (PT-RS) sample sequence using outer-most constellation points corresponding to scheduled modulation order of data channel, and scrambling the phase tracking reference signal (PT-RS) sample sequence with a user equipment-specific sequence.