## 3 Experimental Work
As a result, for a robust transmission scenario of the  
Figure 6: Channel capacity of the multi-carrier OGFDM vs. generalized frequency division multiplexing (GFDM) with F\({}_{\text{DAC}}\) = 4 and 6 GHz. Figure 7: Channel capacity of the multi-carrier OGFDM vs. GFDM with typical and dual oversampling and F\({}_{\text{DAC}}\) = 4 and 6 GHz. OGFDM, a combination of both the NOV and DOV is utilized, where the NOV is highly advised to the good transmission cases while the DOV is strongly recommended for the bad transmission conditions. Regarding the allocation level, as is seen in Figure 8, three vital areas, that are known herein as low boost (LB), medium boost (MB), and high boost (HB), are elected between the 128 QAM and 256 QAM with minimum SNR edges equal to 23 dB and 26 dB correspondingly. The first case (LB) is calculated for a 25%-bit-rate improvement with the SNR threshold equals to 24.4 dB where different possible arrangements of the bit loading map can be shown for this ratio of the enhancement. Worth noting that, compared with the initial OGFDM and GFDM, the number of improved subcarriers that can carry extra bit is doubled and quadrupled respectively. The core idea beyond the LB case is that a quarter of the subcarriers is improved gradually by loading 8 bits rather than 7, which in turns, results in a minor channel capacity increase. In the second case (MB), the threshold of the required SNR is improved to 25.1 dB. Consequently, based on the amended channel conditions, half of the frequency subcarriers can carry an extra number of bits. This, as a result, develops the transmission capacity of the channel by about 50% of the total increment that is possibly achieved between the selected modulations. It is worth pointing that in comparison with the previous multi-carrier systems (OGFDM and GFDM), the number of subcarriers with extra bit ability is enhanced for the developed system of the OGFDM. In the third case (HB), the promoted threshold of the SNR can come up with 75%-bit-rate development in comparison with the previously stated modes (MB, LB). Therefore, at the HB where the recorded SNR equals to 25.1 dB, the number of frequency subcarriers with a further bit is enhanced to 24 improved cases with the developed OGFDM in comparison with only 12 and 6 amended subcarriers with the initial OGFDM and GFDM respectively. Concerning with the modulation levels, an extra BW efficiency is gained herein by applying the adaptive modulation format on the updated system. Besides, the system performance (channel capacity and BER) of the promoted OGFDM is compared with the conventional OGFDM and GFDM under the fixed and adaptive modulation schemes. As is shown in Figure 9, the findings of the experiment declare that the upgraded OGFDM with adaptive modulation can extra improve the transmission bit-rate compared to the OGFDM and GFDM with the fixed modulation format. Hence, in the LB case, the developed OGFDM can achieve about 1.55 dB and 3 dB gains in comparison with the initial OGFDM and GFDM respectively. Worth noting that, these gained ratios can be maximized up to around 1.66 dB and 3.32 dB by moving to the HB. Such a notable improvement is essentially acquired because of the powerful use of the adaptive bit loading  
Figure 8: Three significant adaptive areas for the OGFDM, low boost (LB), medium boost (MB), and high boost (HB) between two sequential fixed modulation schemes (128 and 256 QAM). system, side by side with improving the sampling rate of the OGFDM waveform. The improved channel capacity can play a big role in supplying a good transmission bit rate for each subscriber in the wireless network. The key conditions of this experimented system are listed in Table 2.