An efficient and accurate method is investigated to characterize the electron transport in a two-dimensional modulation doped heterostructure. Schroedinger's equation is solved by using a variational method to obtain the wave functions in closed form. The subband energies, the corresponding wave functions and the carrier concentration are obtained by solving Poisson's and Schroedinger's equations self-consistently. The closed form of the wave functions is then used to calculate the important two-dimensional scattering rates. In order to illustrate the efficiency and the accuracy of our model, the results are compared with those obtained from the conventional self-consistent finite difference scheme. The present model is proved to be more efficient and less complicated when used in material and device characterization.