To demonstrate this fact, Fig. 4 compares the average spectral efficiency of the direct transmission scheme and an MFemtocell-enhanced scheme with two resource partitioning schemes (i.e., orthogonal and non-orthogonal resource partitioning schemes) as a function of the percentage of users associated with MFemtocells.
Also, the comparison is done between maximum signal-to-noise ratio (MAX-SNR) and proportional fairness (PF) scheduling algorithms.
We can see that increasing the percentage of users that communicate with the BS through MFemtocells leads to an increase in spectral efficiency, which is much better compared to the case where users communicate directly with the BS (i.e., the direct transmission scheme).