## 5 Experimental Results
### Performance Evaluation of Proposed Hardware D&F Co-Operative 5G Network
In this regard, we note that the 2 \(\times\) 2 MIMO non-co-operative network achieves the same BER level of the SISO direct link at around \(\mathrm{P_{\mathbf{BS}}}=11\) dBm so that a performance gain of 4 dBm is obtained. Moreover,  
Figure 16: Demodulated PBCH and 5G summary of access link though the Anritsu analyzer. Figure 15: Demodulated and 5G summary of direct link though the Anritsu analyzer. when SISO D&F relay node co-operative network is taken into account, a BER level of \(2.7\times 10^{-2}\) is reached, which supposes an improvement of 4.2 dB in comparison with \(2\times 2\) MIMO non-co-operative network. Nevertheless, the (2 \(\times\) 2 \(\times\) 2) MIMO D&F protocol co-operative system has generated a significantly improved behavior, as can be seen in Figure 17. From the figure, it can be concluded that (2 \(\times\) 2 \(\times\) 2) MIMO D&F relay node acquired a BER performance of \(1.2\times 10^{-3}\) at around \(\text{P}_{\text{\bf BS}}=15\) dBm, implying that 9 dB and 6.7 dB performance gain was successfully reached, in comparison with SISO and 2 \(\times\) 2 MIMO non-co-operative network, respectively. In addition, (2 \(\times\) 2 \(\times\) 2) MIMO D&F network overcomes the performance of the SISO D&F protocol by approximately 3.5 dB. Figure 18 illustrates the achievable BER performance of the proposed downlink relay co-operative 5G network, in which the 256-QAM modulation scheme has been considered. It is indicated from Figure 18 that the implemented downlink 2 \(\times\) 2 MIMO non-co-operative network achieves a lower BER level than the same developed structure with the SISO antenna technique. More explicitly, the error of the 2 \(\times\) 2 MIMO non-co-operative decreases, and the BER level of this structure improves and approaches the 1.5 \(\times\) 10\({}^{-1}\) BER level at around \(\text{P}_{\text{\bf BS}}=15\) dBm, which suggests one gain of the 3.8 dB of the downlink SISO non-co-operative network. Additionally, when the D&F protocol co-operative system has been taken into account, the BER level is decreased considerably, as can be seen in Figure 18. Therefore, for the downlink SISO D&F protocol, an 8 dB performance gain was attained and overcome, with \(\text{P}_{\text{\bf BS}}=8\) dBm in the SISO non-co-operative network. Furthermore, the results clearly show that the SISO D&F relay node has better performance than 2 \(\times\) 2 MIMO non-co-operative structure, for example, the same behavior as the 2 \(\times\) 2 MIMO non-co-operative has been obtained at \(\text{P}_{\text{\bf BS}}=9\) dBm, such that a 6 dB performance gain was achieved. As shown in Figure 18, the BER performance of the (2 \(\times\) 2 \(\times\) 2) MIMO D&F protocol decreases tremendously, which, compared with MIMO non-co-operative and SISO D&F relay node networks, obtains an enhancement of 8.1 dB and 4 dB approximately, respectively. It should be also highlighted that the BER performance of the 64-QAM is lower  
Figure 17: Bit error rate (BER) vs. transmission power of the gnodeB (\(\text{P}_{\text{\bf BS}}\)) of the relay node co-operative 5G network; 64-QAM. than 256-QAM, which was due to the robustness that changes the 64-QAM constellation scheme to 256-QAM. In Figures 19 and 20, we examine the achievable capacity performance of the proposed downlink D&F protocol co-operative 5G network with single and multiple antenna techniques for the 64-QAM and 256-QAM constellation schemes. Therefore, the illustrated performance in Figures 19 and 20 describe the output throughput of the new radio DL-SCH transport channel processing measured by the user equipment, respectively. From the figures it is shown that the achievable capacity performance recorded for the downlink MIMO co-operative and non-co-operative networks reached a higher average throughput than SISO antenna technology in the same environments.