Delay constrained linear transmission of a mixture of Gaussian measurements over a fading channel

Delay constrained linear transmission (LT) of a mixture of Gaussian measurements over an additive white Gaussian noise (AWGN) fading channel is considered. At each time slot (TS), the control center (CC) asks for the measurement of a particular system parameter from the sensor, which is capable of measuring multiple independent system parameters. The average mean-square error (MSE) distortion is studied for Gaussian parameters and a Gaussian fading channel under an average power constraint. The optimal LT scheme is characterized under a strict delay constraint, and a graphical interpretation for the power allocation strategy is presented. Then, two achievable LT strategies are proposed for general delay constraints. It is shown that the performance improves as the delay constraint is relaxed, and when the delay constraint is completely removed, both strategies achieve the optimal performance under certain matching conditions.