# Gyre Precoding and T-Transformation-Based GFDM System for UAV-Aided mMTC Network
## 3 Numerical Results and Relative Discussion
In Figure 13, comparatively improved system performance is noticeable with the system tested under the LDPC and RA concatenated channel-coding technique. It is seen by observing simulated data of all eight users in Figure 13 that the BER varies from approximately 24.39% to 12.00% for a typically granted \(E_{b}/N_{0}\) value of 10 dB. In Figure 14, BER performance of the system under concatenated channel-coding scheme with a combination of (3,2) SPC and RA is quite satisfactory. Over the wide range of SNR from 0 dB to 30 dB, the estimated maximum and minimum BER are found to have values 0.14190 (14.19%) and 0 (0%), respectively. It is seen from Figure 14 that the BER varies from 2.75% to 0.51% for a typically assumed \(E_{b}/N_{0}\) value of 10 dB. It is also observed that in the case of mMTC user 1, BER is reduced from 5.90% to 0.68% with an increase in the SNR value from 6 dB to 16 dB. In Figure 15, BER performance of the proposed system utilizing (3,2) SPC and RA concatenated channel-coding technique has been compared with other GFDM systems introduced in previous works. From a brief description perspective of the systems presented in [39; 41; 42; 43], it can be said that the authors in [41] did a thorough analysis on the applicability of wireless energy harvested GFDM-based cooperative network and presented numerical results in terms of BER. In [42], the effectiveness of localized discrete gabor transform (LDGT) algorithm implemented the GFDM system with varying windowing lengths was studied accounting the BER performance. Authors in [39] conducted a performance evaluative study for a GFDM-assisted NOMA system with respect to BER and achievable rate analysis. In [43], the authors highlighted the effectiveness of a designed pulse shaping filter based on quadratic programming in reducing the OOB radiation and BER performance of the GFDM system. Now, it is quite clearly visible from Figure 15 that the proposed system is showing comparatively better performance in terms of BER against \(E_{b}/N_{0}\) than cooperative GFDM, LDGT-aided GFDM, GFDM-based NOMA, and designed pulse shaping filter implemented GFDM systems. In Figure 16, it is clear from the high BER values that the improved 3D controlled Lorenz mapping system-aided PLS encryption technique is very much effective in offering secure multi-user data transmission. In addition, it is difficult to identify the transmitted data correctly at the receiver without any knowledge of assigned parameter values used in such an encryption technique. Due to the utilization of a channel-dependent precoding technique in this proposed system, the power of different signals at different transmitting channels is varied. As a consequence, PAPR values also vary. It is observable from Figure 17 that at a complementary CDF (CCDF) of \(10^{-3}\), the maximum and minimum PAPR values are 9.5 dB (Transmitting antenna 2) and 8 dB (Transmitting antenna 4), respectively. As it is seen that the variation among all the transmitting channels is well within the PAPR value of 1.5 dB, curves for different channels coincides at some stage. Figure 4:4 Comparative BER performance analysis between the proposed system and other B5G compatible multicarrier systems. In Figure 18, it is observable that the estimated PAPR values at different ground transmitting channels in the proposed system are reasonably acceptable if they are considered with respect to the state-of-the-art. Figure 4:5 BER performance for the different mMTC users without improved 3D controlled Lorenz mapping system-aided PLS decryption scheme. Figure 4:6 Estimated complementary cumulative distribution function (CCDF) of peak-to-average power ratio (PAPR) at different ground transmitting channels of the proposed simulated system. Figure 4:7 Estimated peak-to-average power ratio (PAPR) at different ground transmitting channels of the proposed simulated system.