Chapter 4: Test Results4.1 Graphs and GraphsA Test of OFDM MATLAB Simulation (Screen Log)Figure 4.1: Screen LogTransmitter TracesA carrier can only modulate a certain amount of symbols from a frame. Figure 4.2 shows that for an IFFT size of 1024 and with 497 carriers there are 17 symbols from a frame that are modulated by one carrier. For differential phase shift manipulation, when mapping symbols to phases, the amplitude is assumed to be constant. As shown in Figure 4.3, there will be four phases for QPSK. The graph in Figure 4.4 shows that IFFT containers are almost completely used by carriers. Figure 4.2: Total symbols carried Figure 4.3: Designated carriers on IFFT containers Figure 4.4: Transmitted and receiver phase graphs When the signal after modulation is transmitted on the AWGN channel, it may be introduced with some noise and amplitude clipping may occur as shown in Figure 4.5. In QPSK the phases have a tolerance of 45. With a pixel percentage error of 5%, noise is easily observable on the output image but the information content received is highly usable. A sign of the success of QPSK is shown in the graph of Figure 4.6 with four groups of constellations. Figure 4.5 Figure 4.6 It makes sense to have the values ​​a bit spread out. Figure 4.7 shows that the amplitudes of the received data are not as flat as the original. Figure 4.7 By keeping all the same parameters and simply changing the modulation technique, the simulation time for both the transmitter and receiver is plotted (figure 4.8) and found to be almost the same. This is because the total number of frames did not vary between...... half of the article ......n, James Cook University, Australia, December 2001[17] Y. Zhao and S.-G. Haggman, “Carrier Interference Self-Cancellation Scheme for OFDM Mobile Communication Systems,” IEEE Transactions on Communications, vol. 49, no. 7, pp. 1185-1191, July 2001.[18] M. Kornfeld, “DVB-H – The Emerging Standard for Mobile Data Communication,” Proceedings of the IEEE International Symposium on Consumer Electronics, pp. 193-198, September 2004.[19] R. Burow, K. Fazel, P. Hoeher, O. Klank, H. Kussmann, P. Pogrzeba, P. Robertson, and M.J. Ruf, "On DVB-T system performance in mobile environment," Proceedings of the IEEE Global Conference on telecommunications, vol. 4, pp. 2198-2204, November 2008.[20] J. Rinne, “Some elementary suboptimal diversity reception schemes for DVB-T under mobile conditions,” IEEE Transactions on Consumer Electronics, vol. 46, no. 3, pp. 847-850, August 2000.