terference The in-band interference in Section 2.3.1-2.3.3 is numerically evaluated and plotted for different values of subband width and CR length. Figure 2.3 shows an example of power distributions for the desired signal and interference signal (ICI, f-ISI, and b-ISI) on a subcarrier level, evaluated through (2.22) with FFT size of 1024, subband width of 36 subcarriers in Figure 2.3a and 240 subcarriers in Figure 2.3b. In addition, no CP/CS was added for interference alleviation. It is shown in Figure 2.3 that the theoretical value of in-band interference power matches the simulation result. It is clearly visible that the interference in the wider subband has lower power as a whole than that in the narrower band. Figure 2.3a indicates that uneven power is distributed for both the desired signal and interference signal among subcarriers. Compared to other subcarriers, Desired sig. (sim.) Desired sig. (anal.) Total int. (sim.) Total int. (anal.) ICI (anal.) Forward ISI (anal.) Backward ISI (anal.) Subcarrier index Subcarrier index Figure 2.3 Power of desired signal and interference N = 1024, N cr = 0, N = Na = 512, = 0.6, aq = 0.65. The three contributions (ICI, forward ISI, and backward ISI) to the total interference are evaluated individually from our analytical expressions, which cannot be fulfilled through simulation; thus only their analytical results are plotted. (a) A narrow subband of 3 RBs (36 subcarriers) and (b) a wider subband of 20 RBs (240 subcarriers). 2 Filtered OFDM: An Insight into Intrinsic In-Band Interference those near the edge (edge subcarriers) have lower desired signal power while experiencing higher interference. The two overlapping curves corresponding to the interference power from the previous f-OFDM (f-ISI) and next f-OFDM symbol (b-ISI) indicate the same power distribution due to the symmetry of the filters. The trends are also captured in Figure 2.3b for the wider subband. The maximum, minimum, and average normalized power of ICI/ISI with respect to sub- carriers of the same subban