Half-Duplex Relay Coding for Semi-Orthogonal MARC Interference

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Solution Overview

Problem

Current MARC networks face challenges in improving transmission reliability and spectral efficiency due to non-orthogonal links between transmitters and relays, leading to interference and suboptimal use of spectral resources, which limits network capacity and performance.

Innovation Solution

Implementing a semi-orthogonal MARC system with iterative joint detection/decoding and joint coding in the relay to separate and encode interfering streams, allowing for simultaneous transmission by transmitters and maximizing spectral resource use without increasing power, while providing redundancy information to enhance decoding at the receiver.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If transmitters use non-orthogonal links to relay, then spectral efficiency increases, but interference occurs and transmission reliability deteriorates

Engineering Contradiction:

Improvespectral efficiencyVSAvoidtransmission reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The relay acts as an intermediary that receives signals from multiple transmitters through non-orthogonal links, performs joint detection to separate the interfering streams, and forwards decoded information to the receiver. This mediator approach allows the system to tolerate and resolve interference rather than avoiding it, thereby maintaining high spectral efficiency while ensuring transmission reliability through active interference management at the relay node

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements iterative joint detection and decoding at the relay, where the relay repeatedly processes received signals, refines its estimation of transmitted streams, and updates its decoding decisions. This feedback mechanism allows the relay to progressively reduce the impact of interference and improve detection accuracy, thereby maintaining reliability despite using non-orthogonal links for spectral efficiency

Inventive Principle:

Principle #23Feedback

2Area of stationary object

If transmitters increase power to improve coverage, then system coverage increases, but power consumption increases

Engineering Contradiction:

Improvesystem coverageVSAvoidtransmitter power

Core Design Contradiction:

Area of stationary objectVSUse of energy by stationary object

Solution Approach 1:

The relay serves as a mediator that receives weak signals from transmitters and actively decodes and re-encodes them before forwarding to the receiver. This allows transmitters to operate at lower power levels while the relay compensates for signal degradation through its processing capabilities, thereby extending coverage without proportionally increasing transmitter power consumption

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces the traditional approach of increasing transmitter power (mechanical solution) with signal processing and coding techniques at the relay (information processing solution). The relay's joint detection and decoding algorithms effectively amplify and clean up weak signals, substituting computational power for transmit power, thereby extending coverage without increasing energy consumption at the transmitter nodes

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If orthogonal links are used between transmitters and relay, then interference is avoided, but spectral resource utilization becomes suboptimal

Engineering Contradiction:

Improveinterference avoidanceVSAvoidspectral resource utilization

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

Instead of avoiding interference through orthogonal links as in traditional systems, this invention inverts the approach by deliberately using non-orthogonal links that create interference, then actively managing and resolving that interference through joint detection and decoding at the relay. This inversion allows the system to achieve higher spectral efficiency by allowing frequency reuse while maintaining reliability through sophisticated signal processing

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentEP2507930B1Method for transmitting a digital signal for a semi-orthogonal frame system having half-duplex relay, and corresponding program product and relay device

Publication Date: 2019.03.13 ORANGE SA

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AI summary

The invention relates to a method (1) for transmitting a digital signal intended for a network having at least four nodes including two transmitters, a relay and a receiver separated from one another by means of non-orthogonal links, except between the relay and the destination, between which the link is orthogonal, implementing a spatially distributed network code, including: an encoding step (2), in each transmitter, supplying a code word for every block of K bits of information; a step of transmitting (3), in the transmitters, the code word during aN transmission intervals, a? [0,l]; a step of joint iterative detection/decoding (4), in the relay, in order to separate the interfering streams from the transmitters and to determine, for each stream, a vector representing the K bits of information associated with the code word; a step of joint encoding (5), in the relay, of the two vectors in order to determine redundancy information, and scheduling the relays such as to transmit (6) the redundancy information during the (1-a)N following transmission intervals.