Coded Water-Filling for Multi-User Interference Cancellation

TL;DR

This paper introduces coded water-filling, a novel technique combining rateless coding, early termination, and power allocation to enhance interference cancellation and capacity in multi-user multi-cell wireless systems.

Contribution

It proposes the concept of coded water-filling, integrating variable-length rateless coding with interference cancellation and power allocation, supported by analytical models for capacity gains.

Findings

Interference cancellation improves capacity in AWGN channels.

Robustness of algorithms in fading channels.

Power allocation elevates system capacity.

Abstract

In this paper, we study the system-level advantages provided by rateless coding, early termination and power allocation strategy for multiple users distributed across multiple cells. In a multi-cell scenario, the early termination of coded transmission not only reduces finite-length loss akin to the single-user scenario but also yields capacity enhancements due to the cancellation of interference across cells. We term this technique \emph{coded water-filling}, a concept that diverges from traditional water-filling by incorporating variable-length rateless coding and interference cancellation. We formulate a series of analytical models to quantify the gains associated with coded water-filling in multi-user scenarios. First, we analyze the capacity gains from interference cancellation in Additive White Gaussian Noise (AWGN) channels, which arises from the disparity in the number of bits transmitted by distinct users. Building upon this, we broaden our analysis to encompass fading channels to show the robustness of the interference cancellation algorithms. Finally, we address the power allocation problem analogous to the water-filling problem under a multi-user framework, proving that an elevation in the water-filling threshold facilitates overall system capacity enhancement. Our analysis reveals the capacity gains achievable through early termination and power allocation techniques in multi-user settings. These results show that coded water-filling is instrumental for further improving spectral efficiency in crowded spectrums.