Methods, apparatus, and systems for reducing Peak Average Power Ratio (PAPR) in signal transmissions are described. In one example aspect, a wireless communication method includes determining, for an input sequence, an output sequence. The output sequence corresponds to an output of a convolutional modulation between a set of coefficients and an intermediate sequence. The intermediate sequence is generated by inserting N zero coefficients between coefficients of the input sequence. The number of non-zero coefficients in the set of coefficients is based on N, N being a positive integer. Values of the non-zero coefficients correspond to values between 0 to π/2 to reduce a peak to average power ratio of the output sequence. The method also includes generating a waveform using the output sequence.