A method in a wireless communication transmitter including a baseband processor (310) that configures the transmitter for a particular signal configuration, and a headroom controller (350) for adjusting transmitter headroom based on the particular signal configuration. In one embodiment, the headroom is controlled based on a power metric, for example, a 3rd order polynomial or a peak to average ratio (PAR) metric, that is a function of the signal configuration. In another embodiment, the headroom is adjusted using information in a look up table.