## 5 Results and Discussion
### PRIME: Reed-Solomon Encoding
\begin{table}
\begin{tabular}{l c c c c c c c c c c c c c c c c} \multicolumn{11}{c}{**Header Type B \({}^{*}\)**} & \multicolumn{11}{c}{**Header Type B \({}^{*}\)**} & \multicolumn{11}{c}{**Header Type A**} & \multicolumn{11}{c}{**Header Type A**} & \multicolumn{11}{c}{**Header Type B \({}^{*}\)**} & \multicolumn{11}{c}{**Header Type A**} & \multicolumn{11}{c}{**Header Type A**} & \multicolumn{11}{c}{**Header Type A**} & \multicolumn{11}{c}{**Header Type A**} & \multicolumn{11}{c}{**Related Type A**} & \multicolumn{11}{c}{**Related Type A**} & \multicolumn{11}{c}{**Related Type A**} & \multicolumn{11}{c}{**Related Type A**} & \multicolumn{11}{c}{**Related Type B**} & \multicolumn{11}{c}{**Related Type B**} & \multicolumn{11}{c}{**Related Type B**} & \multicolumn{11}{c}{**DPSK,CC & DPSK,CC & DPSK,CC & DPSK,DPSK,DPSK,CC & DPSK,CC & DPSK,CC & DPSKThe PRIME link budget values including a Reed-Solomon outer encoder are 3.5 dB higher on average than the results without Reed-Solomon. It is an improvement for all the scenarios, with the drawback of decreasing the data transfer rate and increasing complexity in the transmitter and receiver. Reed-Solomon implies a 6.1 dB average increase for modulation schemes without a convolutional encoder. In this scenario, introducing any coding mechanism has its maximum improvement. This is the key reason why this evolution to the PRIME standard would be interesting. Opposed to the peak improvement of modulation schemes without a convolutional encoder, repetition by-4 robust modes have the lowest increase (0.8 dB). Having two encoding mechanisms already, convolutional encoding with repetition code has the consequence that adding Reed-Solomon as a third robustness mechanism has little margin for improvement. Reed-Solomon impact is independent from the header type, both type A and type B headers have an average improvement of 3.9 dB. As Reed-Solomon coding is applied to the payload only, given that the header is robust enough to be decoded, the improvement introduced by Reed-Solomon is the same for both types of header. If analyzed from the point of view of the different disturbance types, Reed-Solomon increases the link budget against every type of noise. Noise sources with the highest tonal component accumulate 5.3 dB improvement. Noises with high tonal component, combined with modulation schemes without convolutional encoder, accumulate 9.8 dB average improvement. Narrowband noises distort fewer subcarriers, but to a higher degree, which is directly related to the Reed-Solomon error recovery mechanism. Focusing on non-tonal noises, the link budget increase goes from 1 to 3.2 dB. The convolutional encoder and Reed-Solomon can be compared as alternative coding and error correction mechanisms. Reed-Solomon has less overhead, so it offers higher values of packet layer data rate, whereas its link budget values are worse than the values using the convolutional encoder. In order to show this, modulations with similar data rates are compared. DQPSK_CC without [PERSON] (Table 4) has 4.2 dB higher link budget than DBPSK with Reed Solomon (Table 6). In a similar way, D8 PSK_CC without Reed-Solomon (Table 4) has 2 dB higher link budget than DQPSK with Reed-Solomon (Table 6). The most interesting scheme for this proposal is D8 PSK with header Type A, with 5.7 dB link budget decrease in exchange for 43.4% increase in terms of data rate if compared to D8 PSK_CC with header type A and without Reed-Solomon (see Table 4). The packet layer data rate shows an average decrease of 6.7% when Reed-Solomon is introduced. This is a low price compared with the increase in the link budget observed. Reed-Solomon includes a fixed overhead of 16 bytes per frame. It should be noted that, in this study, a fixed payload of 256 bytes is used. In real applications, the data rate impact will statistically vary whether the overhead fits in the last symbol's padding or additional OFDM symbols are required.