Usage of different modulation applications in OFDM systems and performance comparison

OFDM (orthogonal frequency division multiplexing) systems are the most efficient use of today's radio frequency spectrum. The system is the simultaneous splitting of a signal into small signals and sending them to the receiver. It is mainly a need in high-capacity data transfer and multi-user systems. Depending on the usage purpose, the OFDM method provides a data transmission with maximum accuracy at the highest speed as long as an appropriate and high-performance modulation type is used. This study performed an FDM communication simulation primarily for multiple data transmissions over a single line. After selecting the carrier frequencies used in FDM, the necessity of the OFDM communication method is proved when considering the high quality of the communication. In the next phase, performance comparisons were made by calculating the BER (Bit error rate) value at different SNR (signal to noise ratio) and multipath fading values of the modulations used in the OFDM method. Specific variable values that the modulation type providing the highest accuracy data transmission has been determined in this study. As a result of the comparison, the best BER value at 8-way communication and 0 SNR was found at 0.28 in the BPSK modulation type. In 8-way transmission and 30 SNR measurements, the lowest BER value was 0.016. In all comparisons made among the used modulation types 'BPSK, QPSK, 8PSK, 16QAM, 32QAM, 64QAM', the lowest BER values were determined in the BPSK modulation type.