Devices that communicate using wireless proximal communications measure pulse width to find distortion in the received signal. The distortion may be due to the devices being too close to one another for a transmission power level currently being used which causes ringing of a receiving coil. The distortion may be used to find a correction that the receiving device may use to correct for the distortion in the received pulse train when decoding the pulse train. The distortion may be used to adjust a transmission power level of the receiving device and/or to send an instruction to the transmitting device to adjust the power transmission power level of the transmitting device. The distortion may be used for other purposes including determining a device depth and/or location for an implanted device, such as an implantable medical device within a body of a patient.