Wireless Fronthaul Link Resource Allocation for Deep Fading

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Solution Overview

Problem

Current wireless fronthaul transmission mechanisms face challenges in maintaining bandwidth efficiency and adaptability under varying atmospheric conditions, such as rain and fading, which can lead to deep fading and loss of management data links, resulting in reduced communication capacity and potential network disruptions.

Innovation Solution

A network node with processing circuitry configured to separate data into RAT payload and management parts, dynamically allocate resources based on channel conditions, and prioritize management data transmission over RAT payload, ensuring continuous connectivity even during poor channel conditions by adjusting bandwidth and modulation formats.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If full bandwidth is allocated to RAT payload transmission, then communication capacity is improved, but robustness to deep fading deteriorates

Engineering Contradiction:
Improvecommunication capacityVSAvoidrobustness to deep fading
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The data stream is segmented into two separate parts: management data and RAT payload. This segmentation allows independent resource allocation and transmission strategies for each part, enabling the system to guarantee management data transmission while adapting RAT payload transmission to channel conditions, thus resolving the contradiction between communication capacity and robustness to deep fading.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the resource allocation between management data and RAT payload based on channel conditions. When deep fading is detected, the system can reduce or suspend RAT payload transmission while maintaining management data transmission, thereby adapting to varying channel conditions and resolving the contradiction between maximizing communication capacity and ensuring robustness.

Inventive Principle:
Principle #15Dynamics

2Reliability

If management data is prioritized during poor channel conditions, then connectivity reliability is improved, but RAT payload quality deteriorates

Engineering Contradiction:
Improveconnectivity reliabilityVSAvoidRAT payload quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

Different quality levels are applied to different parts of the data stream. Management data is transmitted with high reliability guarantees using robust modulation and coding schemes, while RAT payload is transmitted with variable quality depending on channel conditions. This local differentiation of quality requirements resolves the contradiction between connectivity reliability and payload quality.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

During poor channel conditions, the system applies partial action by transmitting only the essential management data while reducing or suspending RAT payload transmission. This partial transmission strategy ensures connectivity reliability is maintained while accepting reduced payload quality, effectively resolving the contradiction.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If bandwidth is reduced for RAT payload, then transmission robustness is improved, but communication efficiency deteriorates

Engineering Contradiction:
Improvetransmission robustnessVSAvoidcommunication efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system dynamically adjusts the bandwidth allocation between management data and RAT payload based on real-time channel conditions. During good channel conditions, more bandwidth is allocated to RAT payload to maximize communication efficiency. During poor conditions, bandwidth is reallocated to maintain management data transmission with robustness. This dynamic adjustment resolves the contradiction between transmission robustness and communication efficiency.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3335525B1Robust wireless radio transmission
Publication Date: 2019.11.06 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3335525B1 patent drawingFigure 1~2b
  • EP3335525B1 patent drawingFigure 3~4
  • EP3335525B1 patent drawingFigure 5

AI summary

There is provided mechanisms for robust wireless radio transmission, preferably for fronthaul wireless radio links. A method is performed by a network node. The method comprises acquiring data to be transmitted on a wireless radio link 130. The method comprises separating the data into a radio access technology (RAT) payload part and a management data part. The method comprises acquiring channel condition values for the wireless radio link. The method comprises dynamically allocating resources between the RAT payload part and the management data part according to the channel condition values. The method comprises transmitting the data over the wireless radio link using said allocated resources. Preferably, the data is common public radio interface (CPRI) data. The RAT payload part may comprises in-phase and quadrature (IQ) samples. The management data part may further comprise pilot tones. The pilot tones may be used to assist mitigation of phase and frequency errors introduced on the wireless radio link 130. In general terms, the CPRI data format embeds a low frequency version of the antenna signal, for example in terms of a sampled baseband version of the antenna signal, to be transmitted and received from a wireless device lio as samples of the analog entity. A CPRI data stream may comprise multiple antenna signals of different RAT formats such as LTE and WCDMA, and I and Q samples from each channel may be interleaved in the CPRI data frames. The share of management data may be increased or decreased according to worsened or improved channel condition values, respectively. The method adaptively determines which modulation and/or coding format from at leat two modulation and/or coding formats with different spectral efficiency values to use according to the channel condition values.