## 5 Results and Discussion
### G3-PLC: Tone Map
#### 5.3.2 Reallocation of the Power Assigned to Inactive Tones  
Table 11 represents the absolute results applying the tone map combinations (Table 8) to G3-PLC with the proposed power reallocation. Table 12 summarizes the incremental results compared to Table 9, i.e., G3-PLC performance results with a standard tone map implementation. On average, the proposed power usage reallocation for the G3-PLC tone map introduces 1.1 dB of improvement. Comparing the column about the link budget of the header and the rest of Table 11, it can be noticed that, in many of the combinations of noise types and transmission configurations, the link budget of the header is no higher than the ones including the payload. This implies that, in those situations, the limiting factor is the decoding of the header, and no improvement on the payload, like the ones proposed about the tone map, will increase the final link budget. This is the case of the robust modes. Tone map power usage reallocation for repetition by-4 robust modes increases 0.2 dB their link budget. Comparing header and ROBO modes columns in Table 11 with the absolute results of this improvement, it is observed that header decoding limits are reached. \begin{table}
\begin{tabular}{l c c c c c c c c c} \hline \hline  & \multicolumn{8}{c}{**Differential**} & \multicolumn{8}{c}{**Coherent**} \\ \hline Parameter & Header & ROBO & DBPSK & DQPSK & DSPSK & ROBO & BPSK & QPSK & 8 PSK & Units \\ \hline SNR required for AWGN & \(-3.6\) & \(-2.2\) & \(1.2\) & \(4.6\) & \(9.8\) & \(-3.6\) & \(-0.8\) & \(2.2\) & \(6.4\) & dB \\ \hline Tonal noise link budget & 46,7 & 46,1 & 44,6 & 30,6 & 21,3 & 46,0 & 44,8 & 44,3 & 32,1 & dB \\ Tonal in-band noise link budget & 39,7 & 39,5 & 37,7 & 23,0 & 11,0 & 39,2 & 37,8 & 37,5 & 23,0 & dB \\ Periodic impulse noise link budget & 29,3 & 28,9 & 26,1 & 26,1 & 20,9 & 28,1 & 27,5 & 27,1 & 19,1 & dB \\ Random impulse noise link budget & 26,9 & 26,9 & 26,7 & 25,3 & 22,3 & 26,9 & 26,9 & 19,7 & 23,9 & dB \\ Intentional communicator link budget & 41,5 & 41,5 & 38,7 & 39,1 & 38,5 & 41,5 & 39,3 & 39,3 & 38,5 & dB \\ \hline Composite link budget (LB\({}_{\text{PHY}}\)) & 44,9 & 44,7 & 43,2 & 40,2 & 36,6 & 44,5 & 43,7 & 42,1 & 38,7 & dB \\ Composite in-band link budget & 32,0 & 31,8 & 30,2 & 24.8 & 18,1 & 31,4 & 30,7 & 28,1 & 22,0 & dB \\ \hline der04 link budget & 30,3 & 29,5 & 28,7 & 27,5 & 25,3 & 28,9 & 28,3 & 27,3 & 26,1 & dB \\ der06 link budget & 30,7 & 29,7 & 29,1 & 28,7 & 26,3 & 29,1 & 28,5 & 27,9 & 26,3 & dB \\ der34 link budget & 57,2 & 56,4 & 53,4 & 49,4 & 44,6 & 57,0 & 56,4 & 53,6 & 47,4 & dB \\ der36 link budget & 52,8 & 52,6 & 50,2 & 45,6 & 40,6 & 52,6 & 52,2 & 50,2 & 43,4 & dB \\ der50 link budget & 2,1 & 2,1 & 1.7 & 1,5 & \(-3.7\) & 1,9 & 1,9 & \(-5.9\) & \(-1.9\) & dB \\ der51 link budget & 7,8 & 7,8 & 7,8 & 6,6 & 5,4 & 7,8 & 7,6 & 0,6 & \(-4.0\) & dB \\ \hline der average link budget & 30,2 & 29,7 & 28,5 & 26,6 & 23,1 & 29,6 & 29,2 & 25,6 & 22,9 & dB \\ \hline \hline \end{tabular}
\end{table} 
Table 11: Absolute results with a tone map power reallocation in G3-PLC. Differential modes have 1.5 dB link budget increase while coherent modes improve 0.7 dB. These values are influenced by the tone map number of '0' selections per mode and the header decoding limits. It was expected a theoretical link budget increase according to Equation (1), with an increase of the power spectral density based on the number of '0'. Nevertheless, robust modulation schemes were close to the header decoding limits, so this power usage technique does not offer the expected improvement. The performance of this tone map implementation shows a high dependency on the different noise types. The gain of redistributing the power of inactive tones will directly depend on the number of '0's of the tone map. ETSI periodic impulse noise and certain DER noises whose selected tone map is '000011' and '000001', where header decoding limits are not reached, have the highest link budget increase of 1.8 dB and 2.1 dB.