Maximizing System Capacity Using Adaptive Coding and Modulation Techniques for Slowly Fading Channels

Abstract

In this paper, an adaptive coding and modulation (ACM) technique is introduced in an attempt to maximize the channel throughout. This technique suggests five different pairs of coding and modulation techniques, starting from low modulation orders and code rates going through higher values. Simulation over additive white Gaussian noise (AWGN) of the physical layer of the system is performed using M-phase shift keying (M-PSK) modulation and convolutional codes with soft Viterbi decoding algorithm. In addition, the channel throughput for each Modulation and coding pair is obtained using specific packet retransmission mechanism. An algorithm for adaptive coding and modulation is developed and the overall throughout of the adaptive system is determined with respect to the received Eb/No values.