Parallel Channel Sensing for LAA Resource Efficiency

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Solution Overview

Problem

In Licensed-Assisted Access (LAA) networks, the limited number of RX RF chains in analog beamforming antennas leads to sequential directional channel sensing, resulting in high overhead and resource waste due to the need to perform channel sensing for each user separately, which reduces the efficiency of resource utilization.

Innovation Solution

Implementing parallel channel sensing within the time duration of an LTE frame structure for multiple radio links, allowing for grouping of links by direction and random back-off window selection, and alternating channel sensing patterns to reduce the period between sensing slots and increase the likelihood of finding available channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If sequential directional channel sensing is performed for each user separately using analog beamforming antennas, then the limited number of RX RF chains can be used, but the overhead and resource waste increase significantly

Engineering Contradiction:
Improvenumber of RX RF chainsVSAvoidchannel sensing overhead
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent combines channel sensing for multiple radio links into a single parallel sensing operation. Instead of sequentially sensing each link separately, the system performs joint channel sensing across multiple links simultaneously, thereby reducing the total sensing time and overhead while still using the limited RX RF chains effectively.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a new dimension to channel sensing by performing sensing in parallel across multiple spatial dimensions (different radio links) simultaneously. This transforms the traditional sequential single-dimension sensing approach into a multi-dimensional parallel sensing framework, enabling efficient utilization of limited RF chains.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If sequential channel sensing is performed for multiple radio links, then the limited RX RF chains can be used, but the resource utilization efficiency decreases

Engineering Contradiction:
Improvenumber of RX RF chainsVSAvoidresource utilization efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent merges channel sensing operations for multiple radio links into a unified parallel sensing process. By combining these operations, the system achieves higher resource utilization efficiency as multiple links are sensed simultaneously rather than sequentially, maximizing the productive use of available RF chains.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent ensures continuous useful action by performing channel sensing for multiple links without idle gaps between sequential operations. The parallel sensing approach eliminates waiting time between sensing different links, maintaining continuous productive activity of the RF chains.

Inventive Principle:
Principle #20Continuity of useful action

3Productivity

If parallel channel sensing is implemented for multiple links, then the resource utilization efficiency improves, but the device complexity increases

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidchannel sensing mechanism complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the channel sensing process into distinct parallel operations for different radio links. Each link's sensing is handled as a separate but simultaneous task, allowing the system to manage complexity through structured segmentation while achieving parallel execution and improved resource utilization.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3202196B1Method and apparatus for data transmission
Publication Date: 2021.09.29 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3202196B1 patent drawingFigure 1
  • EP3202196B1 patent drawingFigure 2
  • EP3202196B1 patent drawingFigure 3(a)~3(b)

AI summary

Embodiments of the present disclosure provide a method at a communications device of a first type that is operable on both a licensed carrier and an unlicensed carrier. The method comprises performing channel sensing on the unlicensed carrier, at different sensing slots within a time duration, for respective links directed to at least two communications devices of a second type that are operable on both the licensed carrier and the unlicensed carrier. The time duration is specified as a portion of a subframe in a frame structure used on the licensed carrier. The method also comprise scheduling transmission on a channel that is determined to be available based on corresponding channel sensing. Correspondingly, there is also provided an apparatus embodied at or as at least part of a communications device of a first type, e.g. a base station that is operable on both a licensed carrier and an unlicensed carrier.