Achievable Degrees of Freedom of the K-user MISO Broadcast Channel with Alternating CSIT via Interference Creation-Resurrection

TL;DR

This paper investigates the maximum degrees of freedom in a K-user MISO broadcast channel with alternating perfect, delayed, and no CSIT, showing that strategic CSIT pattern usage achieves a DoF of K^2/(2K-1).

Contribution

It introduces a novel analysis of the DoF for the K-user MISO BC with synergistic alternating CSIT, deriving a new achievable DoF formula.

Findings

Achieves DoF of K^2/(2K-1) with alternating CSIT patterns.

Demonstrates benefits of synergistic CSIT pattern usage.

Provides comparison with previous delayed and hybrid CSIT results.

Abstract

Channel state information at the transmitter affects the degrees of freedom of the wireless networks. In this paper, we analyze the DoF for the K-user multiple-input single-output (MISO) broadcast channel (BC) with synergistic alternating channel state information at the transmitter (CSIT). Specifically, the CSIT of each user alternates between three states, namely, perfect CSIT (P), delayed CSIT (D) and no CSIT (N) among different time slots. For the K-user MISO BC, we show that the total achievable degrees of freedom (DoF) are given by $\frac{K^{2}}{2K-1}$ through utilizing the synergistic benefits of CSIT patterns. We compare the achievable DoF with results reported previously in the literature in the case of delayed CSIT and hybrid CSIT models.