The pulse widths and amplitudes of the amplitude steps, the pattern or amplitude ordering of the amplitude steps, the number of samples per pulse, and the silence gap lengths can be determined empirically. To determine the transmission pattern of the amplitude steps, the pulse width and amplitude of each amplitude step, the samples per pulse, and the silence gap lengths, three metrics can be considered: transmission performance, calibration time, and power consumption. On the performance side, two metrics are considered: error vector magnitude (EVM) and spectral mask. The goal is to find optimal pulse widths and silence gap lengths, and a transmission pattern that reduce battery current consumption while minimizing calibration time and not violating EVM and spectral mask metrics.

In some embodiments, the transmission pattern of the amplitude steps and silence gaps is one in which each amplitude step increases in amplitude from the previous amplitude step. While this pattern may increase current demand for the continuously increasing amplitudes of pulses, the current demand may not be an issue provided the silence gap lengths between the amplitude steps are sufficiently long to allow the bypass capacitor of the battery to recharge. However, using sufficiently long silence gap lengths can unacceptably increase the time needed for calibration. In some embodiments, the transmission pattern is one in which high and low amplitude steps are interlaced, i.e., alternated, with silence gaps between the amplitude steps. The interlacing reduces the silence gap length needed for recovery, thus reducing the calibration time for the same number of amplitude steps. FIG. 3 is a graph of an example of one pattern of interlaced high and low amplitude steps with silence gaps between amplitude steps.