## 2 Related Works
### Multicarrier Modulations in DVB-T2  
This subsection presents papers that compare OFDM and UFMC performance in DVB-T2 and ameliorate DVB-T2 system performance by improving the signal processing techniques' robustness. It explains first the main improvements of the DVB-T2 system achieved by substituting the Orthogonal Frequency-Division Multiplexing (OFDM) modulation or the QAM constellation shaping techniques by other techniques. Second, it highlights some improvements gathered by enhancing any signal processing techniques like channel coding and MISO in DVB-T2. Multicarrier modulations' (FBMC and UFMC) performance was investigated in DTT systems mainly in DVB-T and DVB-T2, as these systems are both based on OFDM, which presents some compatibilities with FBMC and UFMC. In 2020, filter-based waveforms (UFMC and FBMC) were studied, and their performance was compared to OFDM using DVB-T2 system parameters and its channel coding technique [9]. The numerical results proved that UFMC outperformed FBMC whose performance had previously been confirmed in DVB-T [16] and DVB-T2 systems [17] using BER after demapping and decoding. Furthermore, the spectral efficiency of these waveforms was studied and compared to the 100% OFDM spectral efficiency. With the aim of further improving system performance, the study of advanced constellations (NUCs) was carried out to replace the uniform constellation with a non-uniform constellation. The latter offers advantages in terms of Signal-to-Noise Ratio (SNR) improvement. In 2021, UFMC was jointly studied with a non-uniform constellation (NUC) in the framework of a DVB-T2 system. Indeed, Quadrature Amplitude Modulation (QAM) and OFDM are the modulations techniques used in DVB-T2 [18]. An advanced constellation shape technique called NUC was integrated in ATSC 3.0 as it presented better performance than the square shape constellation. In [18], this constellation was then inserted in both the native DVB-T2 and UFMC-based DVB-T2 systems to measure the impact. The main conclusion was that the UFMC NUC-based DVB-T2 system performance was really better than that of the native DVB-T2 system. Filter-based multicarrier modulations offer better system performance. However, since they exploit the Fourier transform technique differently and incorporate a filtering step in their synoptic scheme, additional complexity could be added. Thus, during the same year, the same authors worked on the computational complexity of filter-based waveforms (FBMC and UFMC) proposed in the DVB-T2 context improvement [19]. The purpose of that study was to highlight the optimal low-complexity algorithm. Furthermore, the compromise between FBMC and UFMC waveforms applied to DVB-T2 in terms of SNR performance gains, spectral efficiency, and complexity was established. The results showed that UFMC was the waveform whose complexity could be reduced to OFDM complexity, and it presented a higher SNR performance gain with a reasonable spectral efficiency. It was demonstrated that parameters such as a number of subcarriers equal to 16384 and a cyclic prefix equal to one-fourth presented the larger CP overhead in DVB-T2. Using these parameters, UFMC was 128.51% spectrally more powerful than OFDM. These performance values were possible with UFMC as there was no need to add CP to achieve good BER performance, unlike OFDM. The previous works presented the DVB-T2 system performance improvement using filter-based multicarrier modulation. In the following works, the main outcomes using other techniques to increase system performance are presented. In 2019, DVB-T2 system performance was investigated using Orthogonal Frequency-Division Multiplexing (OFDM) and realistic DVB-T2 channels [20]. A field measurement was first performed in urban areas such as Jakarta and Bandung cities to record transmission parameters and environmental parameters. These parameters were then inserted into the NYUSIM channel simulator to provide an instantaneous Power Delay Profile (PDP) with 1000 trials that allowed the authors to gather one representative PDP.