Uplink Redundancy Configuration for Interference Mitigation

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Solution Overview

Problem

Heterogeneous wireless communication networks face challenges due to increased sensitivity to interference and asymmetric power capabilities between macro and low-power nodes, leading to inter-cell interference that degrades user experience and affects transmission reliability.

Innovation Solution

A method is implemented to configure wireless communication systems by identifying candidate subframes with reduced interference, where downlink transmissions are synchronized with these subframes to minimize interference, using techniques such as MBSFN ABS patterns and TTI bundling to adjust uplink transmission timing and redundancy, ensuring that downlink transmissions occur during protected periods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If low-power nodes are deployed to increase network density and adapt to traffic needs, then network flexibility and coverage are improved, but inter-cell interference increases and transmission reliability deteriorates

Engineering Contradiction:

Improvenetwork flexibilityVSAvoidtransmission reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The downlink transmission is segmented into multiple redundant copies transmitted in different subframes. The network node transmits the same downlink data in multiple subframes, and the wireless device can successfully decode the data from any one of these copies, thereby overcoming interference in any single subframe and improving transmission reliability in heterogeneous networks

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system prepares for potential interference by transmitting redundant copies of downlink data in advance across multiple subframes. This beforehand cushioning ensures that if interference occurs in one subframe, the wireless device still has alternative copies to decode, thus cushioning against the reliability deterioration caused by inter-cell interference

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Use of energy by stationary object

If low-power nodes operate with reduced transmission power, then energy consumption and cost are reduced, but sensitivity to interference increases and transmission reliability deteriorates

Engineering Contradiction:

Improveenergy consumptionVSAvoidtransmission reliability

Core Design Contradiction:

Use of energy by stationary objectVSReliability

Solution Approach 1:

The interference protection mechanism is applied locally to specific downlink transmissions that are susceptible to interference from low-power nodes. By selectively applying redundant transmission to vulnerable downlink signals rather than increasing overall transmission power, the system protects reliability while maintaining the energy efficiency of low-power node operation

Inventive Principle:

Principle #3Local quality

3Reliability

If redundant transmissions are implemented to protect against interference, then transmission reliability is improved, but network overhead and resource consumption increase

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidnetwork overhead

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

Multiple redundant copies of the same downlink data are merged into the transmission schedule across different subframes. The network node combines the original downlink transmission with additional redundant copies, allowing the wireless device to receive the same information multiple times. This merging approach improves reliability without requiring separate dedicated resources for each transmission attempt

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The wireless device discards interfering or failed transmission copies and recovers the downlink data from successful copies. If one copy is corrupted by interference, the device can discard that copy and successfully decode data from another copy, thereby recovering the intended information without needing to request retransmission

Inventive Principle:

Principle #34Discarding and recovering

Data Source

PatentEP2826188B1Systems and methods for configuring redundant uplink transmissions in a wireless network

Publication Date: 2019.01.09 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

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AI summary

A method for configuring communication in a wireless communication system includes obtaining, at a first network node, information indicating a plurality of candidate sub-frames for downlink transmissions to a wireless communication device in a first cell served by the first network node. Each candidate subframe satisfies a candidate condition that relates to transmissions in a second cell during that subfrarne. The method also includes determining, based on the obtained information, a number of copies of an plink transmission a wireless communication device should transmit in consecutive plink subframes so that a downlink transmission related to the uplink transmission will occur during one of the candidate subframes. Additionally, the method includes configuring the wireless communication device to transmit the determined number of copies of the uplink transmission in consecutive subframes.