Methods, systems, and devices for wireless communication are described. A wireless device may identify a transmission mode for transmission of an input signal to be transmitted. The input signal may thus be modulated according to the identified transmission mode, and the modulated signal may then be transmitted at some power level to produce a transmitted signal having a spectral envelope. In some cases, the spectral envelope may be defined in terms of a power spectral density (PSD) of the transmitted waveform. The PSD may generally define the power of the waveform signal distributed over frequencies of the waveform. Further, the wireless device may control the modulation of the input signal, in addition to the power level of the input signal, to maintain the spectral envelope to be within a spectral mask defined for the implemented transmission mode as well as to conform to spectral flatness parameters.