Shared Spectrum Coexistence via OFDM Symbol Duration Segmentation

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Solution Overview

Problem

Wireless communication systems face challenges in coexistence between enhanced component carrier (eCC) and non-eCC communications, particularly in shared radio frequency spectrum bands, due to interference issues.

Innovation Solution

A method and apparatus for wireless communication that involves contending for access to a shared channel and multiplexing eCC and non-eCC communication windows using orthogonal frequency domain multiplexing (OFDM) with different symbol durations, and implementing time division or frequency domain multiplexing, along with signaling partitioning between communication windows in control channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If eCC and non-eCC communications share a radio frequency spectrum band, then spectrum utilization efficiency is improved, but interference between different CC types increases

Engineering Contradiction:
Improvespectrum utilization efficiencyVSAvoidinterference between CC types
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The shared radio frequency spectrum band is segmented into separate communication windows for eCC and non-eCC transmissions. The base station allocates specific time intervals (communication windows) to each CC type, allowing them to share the spectrum while preventing simultaneous interference. This segmentation enables multiple CC types to coexist in the same frequency band by dividing the time domain into distinct transmission opportunities.

Inventive Principle:
Principle #1Segmentation

2Reliability

If different OFDM symbol durations are used for eCC and non-eCC, then communication performance for each CC type is optimized, but system complexity increases

Engineering Contradiction:
Improvecommunication performanceVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Different OFDM symbol durations are assigned to different communication windows based on the specific requirements of eCC and non-eCC transmissions. Within each communication window, the system uses the appropriate symbol duration optimized for that CC type, while maintaining compatibility with other CC types in their respective windows. This local optimization allows each CC type to achieve its best performance without requiring the entire system to operate at the highest complexity level.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If contention-based access is implemented in shared channels, then fair spectrum access is achieved, but access delay increases

Engineering Contradiction:
Improvefair spectrum accessVSAvoidaccess delay
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The system implements periodic contention opportunities through regularly scheduled communication windows for eCC and non-eCC transmissions. Instead of continuous contention, devices participate in contention at predetermined intervals defined by the communication window structure. This periodic approach balances fair access opportunities with reduced waiting time, as devices know when to expect the next contention opportunity rather than experiencing continuous delays.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3298852B1Techniques for coexistence between enhanced component carrier communications and non-enhanced component carrier communications
Publication Date: 2020.06.10 QUALCOMM INC
  • EP3298852B1 patent drawingFigure 1
  • EP3298852B1 patent drawingFigure 2
  • EP3298852B1 patent drawingFigure 3

AI summary

Techniques are described for wireless communication. One method for wireless communication at a base station includes contending for access to a shared channel of a shared radio frequency spectrum band, and multiplexing first component carrier (CC) communication windows and second CC communication windows in the shared channel. A duration of orthogonal frequency domain multiplexed (OFDM) symbols of the first CC communication windows may be different from a duration of OFDM symbols of the second CC communication windows, and the multiplexing may occur on the shared channel upon winning contention for access to the shared channel. One method for wireless communication at a user equipment (UE) includes monitoring a shared channel of a shared radio frequency spectrum band for a first CC Listen Before Talk (LBT) frame, and receiving, in a second CC preamble, an indication of the first CC LBT frame.