Coding for Quasi-Static Fading Channel with Imperfect CSI at the Transmitter and Quantized Feedback

TL;DR

This paper develops a modified Schalkwijk-Kailath coding scheme for quasi-static fading channels with imperfect and quantized feedback, effectively eliminating decoding errors caused by CSI imperfections and enhancing communication reliability.

Contribution

It introduces a novel SK-type scheme using modulo lattice functions and auxiliary signals to handle imperfect CSI and quantized feedback in fading channels.

Findings

Decoding error due to imperfect CSI can be eliminated.

The proposed scheme achieves reliable communication in fading channels.

Efficient coding design for channels with imperfect feedback.

Abstract

The classical Schalkwijk-Kailath (SK) scheme for the additive Gaussian noise channel with noiseless feedback is highly efficient since its coding complexity is extremely low and the decoding error doubly exponentially decays as the coding blocklength tends to infinity. However, its application to the fading channel with imperfect CSI at the transmitter (I-CSIT) is challenging since the SK scheme is sensitive to the CSI. In this paper, we investigate how to design SK-type scheme for the quasi-static fading channel with I-CSIT and quantized feedback. By introducing modulo lattice function and an auxiliary signal into the SK-type encoder-decoder of the transceiver, we show that the decoding error caused by the I-CSIT can be perfectly eliminated, resulting in the success of designing SK-type scheme for such a case. The study of this paper provides a way to design efficient coding scheme for fading channels in the presence of imperfect CSI and quantized feedback.