A method and system for reducing the power to average ratio (PAR) at the transmitter after the up sampling and interpolation filter. In the time domain, Side Tone Packets Injection (STPI) system and method detects the optimal peaks that will result in having a low PAR at a sampling rate of T/K and combines an optimal binary and a PAR-lowering sequence and an upsampled, interpolated original discrete time signal at the scale of one extended symbol for multi-carrier modulation and at the scale M of symbols for single-carrier modulation. STPI does not require peaks search and processing at the scale of many time samples, does not require iterative Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) processing thus, allowing the receiver not to perform extra demodulation.