Data Throughput Maximization Using Adaptive Modulation for Single Carrier Base Band Transmission System

This paper examines the benefits of using adaptive modulation in terms of spectral efficiency and probability of bit error in single carrier baseband systems. Specifically, the performance enhancement has been examined using channel quality indicator in conjunction with adaptive modulation. The paper investigates the output (best modulation scheme) on basis of channel quality indicators (SNR, Doppler shift, and BER) of different modulation types (BPSK, QPSK, and M-QAM) from the point of view of higher data rates. The channel used here is the Rayleigh fading channel corrupted by AWGN. The findings regarding the advantages of using predictive measures to foresee the state of the channel is used for the adjustments to transmissions accordingly. This work gives an idea when channel prediction is most valuable to adaptive modulation and when it is weak. Matlab program has been used to implement the whole system. Keywords—Adaptive Modulation, Bit Error Rate (BER), Signal to Noise Ratio (SNR), Digital Modulation Schemes, Equalization and channel estimation, Rayleigh Fading Channel, Doppler Effect and Additive White Gaussian Noise (AWGN).