The sparsely pulsed ultra-wideband (UWB) waveform has to be detected using efficient search strategies. Consecutive serial search (CSS) and permuted search strategies have been used for pulse detection. CSS results in a large average acquisition time when low duty cycle pulses are used. Permuted search strategies circumvent this problem by exploiting the dense multipath characteristic of the UWB signal. A host of parameters influence the acquisition performance in the case of CSS and permuted search strategies. This paper discusses the significance of step size in the acquisition, performance of coherent impulse radio ultra-wideband (IR-UWB) receivers. Using theoretical analysis and simulations, it is established that for channel models with different multipath spreads, the step size minimally affects the acquisition performance of a single pulse correlator in the case of permuted search strategies. For CSS, the acquisition performance changes with, step size.