PDCCH Scheduling via Maximum Independent Set

TL;DR

This paper addresses the challenge of selecting PDCCH candidates in 5G to optimize data transmission by formulating it as an MWIS problem and proposing a practical greedy solution with performance guarantees.

Contribution

It introduces a novel formulation of PDCCH candidate selection as an MWIS problem and proposes the WDR Greedy algorithm for efficient, near-optimal solutions.

Findings

WDR Greedy offers a favorable performance-to-complexity trade-off.

The MWIS formulation captures the PDCCH candidate selection problem effectively.

The proposed method provides theoretical performance guarantees.

Abstract

In 5G, the Physical Downlink Control CHannel (PDCCH) carries crucial information enabling the User Equipment (UE) to connect in UL and DL. UEs are unaware of the frequency location at which PDCCH is encoded, hence they need to perform blind decoding over a limited set of possible candidates. We address the problem faced by the gNodeB of selecting PDCCH candidates for each UE to optimize data transmission. We formulate it as a Maximum Weighted Independent Set (MWIS) problem, that is known to be an NP-hard problem and cannot even be approximated. A solution method called Weight-to-Degree Ratio (WDR) Greedy emerges as a strong contender for practical implementations due to its favorable performance-to-complexity trade-off and theoretical performance guarantees.