On the Linear Precoder Design for MIMO Channels With Finite-Alphabet Inputs and Statistical CSI

The theoretic limit on the information rate that a communication channel can support with arbitrary low probability of error is referred to as channel capacity. This capacity is achievable with independent Gaussian distributed inputs for parallel Additive White Gaussian Noise (AWGN) channels and with correlated Gaussian inputs for Multiple-Input Multiple-Output (MIMO) channels. Even though Gaussian inputs are theoretically optimal, they are rarely realized in practice. Alternatively, inputs are usually taken from a finite-alphabet constellation set, such as Phase Shift Keying (PSK) modulation and Quadrature Amplitude Modulation (QAM), which departs significantly from the Gaussian assumption.