ANALISA SISTEM KOMUNIKASI OFDM DENGAN TEKNIK MODULASI QPSK DAN 16 QAM UNTUK PERHITUNGAN BER PADA KANAL AWGN DAN RAYLEIGH FADING
OFDM (Orthogonal Frequency Division Multiplexing) system is a transmission technique with multiple frequencies are mutually perpendicular (orthogonal). OFDM system is used to transmit multimedia data is generally large required data rates with quite high. Sending data at high speed, it can cause multipath fading conditions that affect the BER (Bit Error Rate). Then, performed simulations on the OFDM system to be able to get the value of BER is small. OFDM system simulation is done with QPSK (Quadrature Phase Shift Keying) and 16 QAM (Quadrature Amplitude Modulation) modulation. From the simulation results OFDM system with QPSK modulation techniques in AWGN Channel has a value of BER is relatively small at 0.1318 at SNR 0 dB and 0.0002 at SNR 30 dB. While in Rayleigh fading channel with 16 QAM modulation obtained BER value is 0.9987 at SNR 0 dB, whereas at SNR 30 dB that is close to zero. This indicates that the OFDM system simulation is done with QPSK modulation in AWGN Channel showed better conditions for BER obtained are relatively small.