Adaptive Relay Schemes for Virtual Full-Duplex Wireless Networks

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Solution Overview

Problem

The challenge in wireless communication networks is to enhance data throughput in densely deployed wireless access nodes without the high cost of optical-fiber-based backhaul solutions, particularly in existing infrastructure, where wireless self-backhaul is a viable but inefficient alternative due to limitations in existing relay schemes.

Innovation Solution

The implementation of an adaptive relay scheme using half-duplex relay nodes that operate in alternating time slots, employing either decode-and-forward or quantize-map-and-forward encoding schemes based on channel conditions, and alternating between two disjoint paths to achieve virtual full-duplex functionality, thereby optimizing data transmission rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If wireless self-backhaul is used instead of optical-fiber-based backhaul, then installation cost is reduced, but data throughput is insufficient

Engineering Contradiction:

Improveinstallation costVSAvoiddata throughput

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The relay nodes are divided into two distinct groups (odd-time relay group and even-time relay group) that operate on alternating time slots. This segmentation allows the system to achieve full-duplex functionality using half-duplex relays, effectively doubling the data throughput compared to traditional half-duplex relay schemes while maintaining cost-effective wireless infrastructure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system employs periodic time-slot allocation where odd-time relay groups transmit during odd time slots and even-time relay groups transmit during even time slots. This periodic alternation enables continuous data transmission in both directions, achieving virtual full-duplex operation and significantly improving data throughput without requiring expensive optical fiber infrastructure.

Inventive Principle:

Principle #19Periodic action

2Device complexity

If half-duplex relay nodes are used, then device complexity is reduced, but channel utilization is inefficient

Engineering Contradiction:

Improverelay node complexityVSAvoidchannel utilization

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The system pre-allocates specific time slots for each relay group (odd-time slots for odd relay groups, even-time slots for even relay groups) before transmission begins. This preliminary arrangement ensures that half-duplex relay nodes can operate efficiently without complex real-time switching, while achieving full-duplex channel utilization through coordinated alternating transmissions.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP3248322B1Adaptive relay schemes and virtual full-duplex relay operation

Publication Date: 2020.01.01 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

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AI summary

A wireless communication system comprises a source node, a destination node, and a plurality of half-duplex relay nodes disposed between the source node and the destination node. The half-duplex relay nodes are configured in two disjoint paths each comprising an equal number of hops from the source node to the destination node. The source node is configured to alternately transmit information via the two disjoint paths in alternating time slots, and the destination node is configured to alternately receive information via the two disjoint paths in alternating time slots.