Noisy Index Coding with Quadrature Amplitude Modulation (QAM)

This paper discusses noisy index coding problem over Gaussian broadcast channel. We propose a technique for mapping the index coded bits to M-QAM symbols such that the receivers whose side information satisfies certain conditions get coding gain, which we call the QAM side information coding gain. We compare this with the PSK side information coding gain, which was discussed in [1]. Keywords—Index coding, AWGN broadcast channel, M−QAM, QAM side information coding gain.