s available at the femtoBS tier. Also, since femtoBS tier uses NOMA to serve the offloaded macroU, the outage probability of different values of q is plotted to show the impact of channel gain difference between the offloaded macroU and the available PU at the femtoBS on the outage probability of the offloaded macroU. The first thing to observe in all the plots of Fig. 5.7 is that offloading always yields better performance as compared to when no offloading is performed and the macroU is served only by the macroBS tier. Furthermore, Fig. 5.7a reveals the plot for q = 0.1, which indicates a large difference in the channel gain difference between the offloaded macroU and the pairing user. A large channel gain difference indicates that the designated CU will have a much better channel gain as compared to the designated EU. As a result, it is evident from Fig. 5.7a that when the offloaded macroU is served as a CU at the femtoBS tier, the offloaded macroU achieves an enhanced outage probability. On the other hand, under the given channel gain difference, if the offloaded user is served as an EU, the outage probability achieved is nearly similar to when the offloading is performed at the femtoBS tier without NOMA. Figure 5.7b is plotted for q = 0.5. As the value of q increases, it indicates that the difference in channel gain between the offloaded macroU and the pairing user decreases. It is further observed that whether offloaded macroU is served as CU or EU, the outage performance is better as compared to when offloading is done at the femtoBS tier without NOMA. Under the selected value of q, it is seen that the 5 NOMA for 5G and Beyond Wireless Networks - MacroU (no offloading) - offloading to FemtoBS (no NOMA) offloading to FBS tier as CU offloading to FBS tier as EU Transmit SNR MacroU (no offloading) - offloading to FemtoBS (no NOMA) offloading to FemtoBS as CU offloading to FemtoBS as EU Transmit SNR MacroU (no offloading) - offloading to FemtoBS (no NOMA) offloading to FemtoBS as CU offloading to FemtoBS as EU 