eNB Scheduling for P2P Links to Mitigate Near-Far Interference

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Solution Overview

Problem

Existing OFDMA communication systems face near-far interference issues in peer-to-peer communication scenarios, where high-power signals desensitize receivers, leading to reduced detectability of low-power signals, especially in mixed networks with direct station-to-station communication.

Innovation Solution

The method involves an evolved Node B (eNB) identifying and allocating resources for peer-to-peer communications by creating peer sets based on measured performance metrics, determining excluded and preferred timeslots, and marking potential resources in a resource allocation map to avoid near-far interference, using proactive and reactive scheduling techniques to dynamically adjust resource allocations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If peer-to-peer communication is allowed in OFDMA networks, then network versatility and communication flexibility are improved, but near-far interference occurs where high-power signals desensitize receivers and reduce detectability of low-power signals

Engineering Contradiction:
Improvecommunication flexibilityVSAvoidnear-far interference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the time-frequency resource space into distinct regions and timeslots, assigning different peer sets to different segments. By dividing the communication resources and creating separate peer sets (first peer set, second peer set, third peer set), the system prevents high-power and low-power signals from interfering with each other while maintaining versatile peer-to-peer communication capabilities.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by assigning different communication characteristics to different peer sets. The first peer set uses first timeslots with specific resource allocations, while the second and third peer sets use second timeslots with different resource allocations. This localized differentiation ensures that each peer set operates with optimized parameters suitable for its specific communication scenario, reducing near-far interference.

Inventive Principle:
Principle #3Local quality

2Productivity

If multiple peer sets communicate simultaneously in the same timeslot on different frequency sub-channels, then resource utilization efficiency is improved, but high-power transmitting signals desensitize receivers and cause loss of information

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidsignal detectability
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent transitions from purely frequency-domain separation to time-frequency domain separation by introducing distinct timeslots for different peer sets. The first peer set communicates in first timeslots while the second and third peer sets communicate in second timeslots. This dimensional change in resource allocation prevents simultaneous high-power transmissions that would desensitize receivers, while still achieving high resource utilization through efficient time-frequency packing.

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

Solution Approach 2:

The patent introduces an evolved Node B (eNB) as an intermediary that centrally coordinates and schedules resource allocations for all peer sets. The eNB determines resource allocations, assigns timeslots, and manages peer set communications to prevent near-far interference. This intermediary control mechanism ensures that resource utilization is maximized while signal detectability is maintained through intelligent scheduling.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If centralized scheduling is used to manage peer-to-peer communications, then near-far interference is reduced through coordinated resource allocation, but device complexity and scheduling overhead increase

Engineering Contradiction:
Improvenear-far interferenceVSAvoidscheduling complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent manages scheduling complexity by changing and optimizing key parameters such as peer set identification, timeslot allocation patterns, and resource block assignments. The eNB dynamically adjusts these parameters based on network conditions, traffic demands, and interference measurements. By systematically varying these parameters, the system reduces near-far interference while keeping the scheduling mechanism manageable through structured parameter control.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2798894B1Method and apparatus for scheduling peer-to-peer communication links
Publication Date: 2017.03.29 MOTOROLA SOLUTIONS INC
  • EP2798894B1 patent drawingFigure 1
  • EP2798894B1 patent drawingFigure 2
  • EP2798894B1 patent drawingFigure 3

AI summary

An evolved Node B creates or updates peer sets from measured performance information received from one or more stations. The measured performance information includes at least one quality metric associated with a downlink signal sent from the evolved Node B to the one or more stations. The evolved Node B determines excluded timeslots and preferred timeslots based on current resource assignments in each timeslot and based on the peer sets, marks potential resources in an uplink portion of a resource allocation map, and allocates one of the potential resources for peer-to-peer communication between a transmitter station and one or more receiver stations.