Measurements of magnetoresistance oscillations have been performed for a twodimensional electron gas where two subbands are occupied to study processes of inter- and intra-subband scattering. Analysis of the temperature dependence of the oscillations allowed us to estimate independently inter- and intra-subband scattering times in the subbands. It has been found that the mobility in the first subband is mainly determined by the intra-subband scattering events, while that in the second subband is limited by processes of inter-subband scattering
