Analogue joint source-channel coding for multiple input multiple output–orthogonal frequency division multiplexing systems

Abstract

[Abstract]: Analogue joint source-channel coding (JSCC) has been shown to approach the optimal distortion-cost trade-off when transmitting over additive white Gaussian noise channels. In this work, we consider analogue JSCC over frequency-selective channels using orthogonal frequency division multiplexing (OFDM) modulation and multiple antennas at transmission and/or reception, that is, using a multiple input multiple output(MIMO)-OFDM system. Because of its high complexity, optimal Minimum Mean Square Error (MMSE) analogue JSCC decoding is infeasible in MIMO-OFDM systems and a practical two-stage decoding approach made up of an MMSE estimator followed by a maximum likelihood decoder is proposed instead. Three different alternatives for system optimisation are considered: non-adaptive coding, adaptive coding and adaptive coding with precoding. We show that the three considered strategies approach the optimal distortion-cost trade-off, but the best performance is obtained with the adaptive coding scheme when precoding is utilised.