Degradedness Under Cooperation

2025-01-15

AI Summary

This work addresses the fundamental capacity limits of cooperative communication in broadcast and relay networks under non-physically-degraded channel conditions. Confronting the looseness of the cut-set bound and the limited applicability of classical degradation models (e.g., physically or stochastically degraded channels), we introduce two novel, rigorously defined degradation notions: “strongly sub-noisy” and “strongly more capable.” Leveraging information-theoretic analysis and capacity region bounding techniques, we establish that decode-and-forward (D&F) achieves the capacity region under finite conference rates; we obtain a partial exact characterization of the capacity region for a class of cooperative broadcast channels; and we prove the tightness of the cut-set bound for several canonical relay channels—including multi-relay and diamond networks. These results extend the theoretical foundations of capacity analysis for non-degraded networks and provide a new analytical framework for designing highly reliable cooperative transmission systems.

Technology Category

• Game Theory and Economic Paradigms: Cooperative Game Theory
• Constraint Satisfaction and Optimization: Other Foundations of Constraint Satisfaction
• Reasoning under Uncertainty: Relational Probabilistic Models

Application Category

• Social Networks and Social Media: Social media analysis through the lenses of networks
• Graph Algorithms and Modeling for the Web: Algorithms and analysis for incomplete, noisy, or partially observed Web-related graphs
• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization

Abstract

We study cooperation problems in broadcast and relay networks, where the receivers do not satisfy the classical physical degradedness assumptions. New notions of degradedness, strongly less noisy and strongly more capable are introduced. We show that under these conditions, decode and forward (D&F) is optimal for classes of cooperative systems with limited conference rates, thus yielding new capacity results for these systems. In particular, we derive bounds on the capacity region of a class of broadcast channels with cooperation, that are tight on part of the capacity region. It is shown that the cut-set bound is tight for classes of primitive relay and diamond channels, beyond the physically or stochastically degraded models.

Problem

• Cooperative Communication
• Broadcast and Relay Networks
• Capacity Limits

Innovation

• Collaborative Broadcasting
• Enhanced Degradation Concepts
• Decoding and Forwarding Superiority