The total throughput of primary system, as shown in Eq. (7), includes the throughput of Case A, Case B, and Case C together, which have been analyzed in Section 4. We will validate the analytical results using Monte Carlo simulations.
It is noted that the optimal received power at relay for single antenna in HD case and FD case is smaller than those schemes with dual antennas, and the highest instantaneous throughput of FD case outperforms the HD case.
It shows that the throughput performance of case 1 is better than case 2 and case 3, since case 1 uses the proposed algorithm which improves the Sink's decoding rate and then improves the throughput.
It shows that the throughput performance of case 1 is better than case 2 and case 3; since case 1 has the highest decoding rate of the Sink, it can improve reception of data packets at the Sink.
This improvement is clearly shown by comparing Figure 6 to Figure 9. Here, the cell throughput of both CARA cases strongly increases when the traffic changes to FTP.
Figure 7 Throughput of the general case where STAs in each cluster C i suffer from event-synchronisation errors with randomly chosen probability.
Although downgrading from OFDMA could potentially decrease the available throughput for broadcast messages, such control channels are known for having very low overhead and a low throughput of, in the case of the PBCH, just 350 bps[1].
The normalised throughput of the worst case scenario, where all STAs encounter synchronisation errors with probability one, is plotted in Figure 5. Normalised throughput is a unitless parameter which is defined by the time used for payload transmission divided by the total time needed for that transmission, i.e. Tslot.
We can see that all the three approaches achieve a throughput of 100% in all cases.
We see that the throughput of SUs in the case with retrials is larger than that in the case without retrials, because the retrial phenomenon of SUs leads to higher channel utilization of SUs. Figure 2(b) shows the loss probability of SUs increases as the arrival rate λ1 of PUs increases.
