Wireless Networks p out 2--ana(a) = 2.5, b = 3) p out 2--sim(a = 2.5, b = 3) p out 2--ana(a) = 6.5, b 4) p out 2--sim(a) = 6.5, b = 4) p out 2--high SINR approx p out 1--ana p out 1--sim Transmission SNR of the BS in dB Figure 4.8 Outage performance for both UEs with comparison to analytical results. transmission SNR becomes larger, the gap becomes less apparent. The reason is as SNR becomes larger, the harvested energy becomes a constant M; thus, the outage performance becomes the same regarding different a and b values, as shown in the high SNR approxi- mation part. Note that the non-linear response will only make sure the harvested energy does not exceed M. In some rare occasions, we can have PO R < R , which clearly violates the physical meaning in our model. So these events are excluded from the results. The outage performance for UE 2 as the function of B is shown in Figure 4.9. The param- eters used for this study are a = 2, PBR = 40 dB. The simulation and analytical results for UE 2 are both presented here and they match well with each other. With the increase of B, the outage probability also increases. The increase slope slows down as B further increases, due to the fact that B is the portion of power assigned to energy harvest unit. The less power remained for transmitting, the higher outage probability it will have. The inconsistence between simulation and analytical results when B = 0.1 comes from the excluded events when pc R PEH 4.2.5 Summary In the first part of the chapter, we analyze the outage performance of two NOMA relay- ing schemes. NOMA cooperative scheme needs two time slots to complete one round communication. It uses NOMA in the first time slot and uses DPC precoding in the second time slot for cooperation. NOMA TDMA scheme needs three time slots to complete one round communication. It uses NOMA in the first time slots and then TDMA in the second and third time slots. SIC error propagation is considered in the analysis and the performance degradation is evaluated. The analytical results