Single pulses as emission from multiple subsources
  Single pulses of pulsar radio emission are modeled as superposition of radiation originating from many small subsources that are randomly distributed in the emission region. The individual subsources are given an intrinsic finite angular beaming. This model can produce fluctuations in intensity and pulse profiles that are similar to the microstructure observed in some pulsars. Statistics of the phase resolved flux density of a simulated single pulse can be approximated by a lognormal distribution, which is in good agreement with observations. 
Qinghuan Luo