SoftPHY-based Adaptive Modulation and Coding for BIC-OFDM Systems

Abstract

This paper describes the exploitation of physical layer confidence in bits (SoftPHY) in order to improve the rate selection in a bit-interleaved coded orthogonal frequency division multiplexing (BIC-OFDM) system. Instead of relying on a measured instantaneous bit error rate (I-BER) from received packets, we built a closed-form I-BER expression that gives accurate and simple functional mapping between the instantaneous channel state and the selected set of modulation level and coding rate. The accuracy of the rate selection and the enhancement of the proposed scheme are confirmed through Monte-Carlo simulations.