Time Slot Interference Mitigation in Wireless Transceivers

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Solution Overview

Problem

Broadband wireless data systems face interference issues due to signal overlap in contiguous geographical areas, where large channel bandwidths are required but not available in large spectral blocks, leading to minimal interference protection.

Innovation Solution

The method involves dividing a channel into time slots with a guard time interval, ensuring no overlap between slots, allowing each time slot to operate at 50% capacity, and shifting communications to the device with the strongest signal in overlapping areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If devices operate in overlapping frequency ranges in contiguous geographical areas, then spectral efficiency is improved, but co-channel interference increases

Engineering Contradiction:
Improvespectral efficiencyVSAvoidco-channel interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The channel is divided into multiple time slots, segmenting the continuous frequency spectrum into discrete time-based segments. This allows different devices to operate in the same frequency range at different times, eliminating co-channel interference while maintaining spectral efficiency through time-division multiplexing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Devices operate in a periodic manner by alternating between active transmission time slots and inactive guard time intervals. This periodic operation pattern ensures that overlapping frequency ranges are used at different times, preventing interference while maximizing spectral utilization through structured time-division access.

Inventive Principle:
Principle #19Periodic action

2Reliability

If guard time interval is increased to prevent signal overlap, then interference protection is improved, but data transmission capacity decreases

Engineering Contradiction:
Improveinterference protectionVSAvoiddata transmission capacity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The guard time interval duration is optimized as a critical parameter, setting it to the minimum value necessary to prevent signal overlap (corresponding to maximum propagation delay). This parameter optimization provides sufficient interference protection while minimizing the time lost to guard intervals, thereby maximizing data transmission capacity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The guard time interval is set to exactly the minimum duration needed to prevent interference (maximum propagation delay), avoiding excessive guard times that would unnecessarily reduce capacity. This partial action approach provides just enough protection against interference while preserving maximum data transmission efficiency.

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If devices switch between time periods rapidly, then frequency utilization is improved, but hardware switch-over time increases

Engineering Contradiction:
Improvefrequency utilizationVSAvoidhardware switch-over time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The guard time interval is positioned between active time slots to prepare for upcoming signal transitions. This preliminary action allows hardware to complete switch-over operations during the guard interval before the next active transmission begins, ensuring smooth transitions without compromising frequency utilization efficiency.

Inventive Principle:
Principle #10Preliminary action

4Productivity

If time slots are tightly packed to maximize capacity, then spectral efficiency is improved, but signal overlap risk increases

Engineering Contradiction:
Improvespectral efficiencyVSAvoidsignal overlap prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The guard time interval acts as an intermediary element between adjacent active time slots. This intermediary buffer prevents direct contact between signals from different devices, eliminating the risk of signal overlap while allowing time slots to be tightly packed for maximum spectral efficiency. The guard interval mediates between the conflicting requirements of capacity and reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP1902527B1Method and system for mitigating co-channel interference
Publication Date: 2016.08.31 TELCOM VENTURES LLC
  • EP1902527B1 patent drawingFigure 1
  • EP1902527B1 patent drawingFigure 2
  • EP1902527B1 patent drawingFigure 3

AI summary

A method of communicating data between a first transceiver and any of a plurality of second transceivers (figure 1 ), wh areas serviced by each of the plurality of second transceivers either overlap or are adjacent. The method comprises operating the first transceiver and the plurality of second transceivers in an overlapping frequency range. Each of the plurality of second transceivers operates in a time period different from a time period of another of the plurality of second transceivers.