Figure 12

D2D sum power with power loading in Scenario 1 and 2 (2 × 4 MIMO). Average sum power is illustrated in D2D mode with optimized and heuristically set SINR targets (2 × 4 MIMO) and with power loading optimization in Scenario 1 (upper) and Scenario 2 (lower). Power loading helps further reduce the required power to reach the sum rate target (the feasibility probability is roughly the same as without power loading (Figure 11) in both scenarios.) In Scenario 2, the average sum power is increased since UE1 and UE3 are closer to Rx UE and thus, the received interference is higher than in Scenario 1.