DRX Cycle Time Division for D2D Cellular Receiver Sharing

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Solution Overview

Problem

Device-to-Device (D2D) capable wireless devices face challenges in simultaneously receiving cellular and D2D signals due to limited receiver resources, leading to missed data packets and increased transmission delays, which degrade system performance.

Innovation Solution

Implementing non-overlapping time periods within Discontinuous Reception (DRX) cycles for cellular and D2D operations, allowing devices to perform both types of operations during separate times within a DRX cycle, configured based on predefined rules, autonomous determination, or network signaling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a D2D capable wireless device receives cellular signals on the Downlink carrier frequency and D2D signals on the Uplink carrier frequency simultaneously, then the device can maintain both cellular and D2D connections, but the limited receiver resources cause the device to miss data packets and increase transmission delays

Engineering Contradiction:

Improveability to receive both cellular and D2D signalsVSAvoiddata packet reception reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the reception time into non-overlapping time periods within DRX cycles, allocating specific time slots for cellular signal reception and D2D signal reception. This time-division approach divides the limited receiver resources into separate intervals, allowing the device to sequentially receive both types of signals without simultaneous resource conflicts, thereby maintaining reliability while supporting dual functionality

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent dynamically adjusts the DRX cycle configuration based on activity detection. When D2D activity is detected, the device transitions to a D2D-active state that modifies the DRX timing parameters, allowing flexible adaptation of reception schedules. This dynamic reconfiguration enables the system to optimize resource allocation in real-time based on actual communication needs, resolving the contradiction between versatility and reliability

Inventive Principle:

Principle #15Dynamics

2Productivity

If the D2D capable wireless device uses its receiver resources for D2D operation at a given time, then D2D communication is maintained, but cellular data scheduling is missed and packet transmission delay increases

Engineering Contradiction:

ImproveD2D communication efficiencyVSAvoidpacket transmission delay

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The patent implements preliminary action by detecting D2D activity in advance and proactively adjusting the DRX cycle configuration before cellular data scheduling opportunities are missed. The device monitors for D2D signals and, upon detection, pre-configures the receiver timeline to prioritize D2D operations during appropriate time periods, preventing cellular scheduling conflicts before they occur rather than reacting after data is missed

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent employs periodic DRX cycles that alternately allocate time periods for cellular and D2D operations. This periodic structure creates predictable, repeating patterns of resource allocation where the receiver switches between cellular and D2D modes in regular intervals. The periodic nature ensures that both communications receive dedicated attention cycles, preventing permanent loss of either service while maintaining overall system productivity

Inventive Principle:

Principle #19Periodic action

3Reliability

If the network increases resources for PDCCH to compensate for missed PDCCH, then cellular DL capacity is maintained, but more resources are consumed for PDCCH and interference on those resource elements increases

Engineering Contradiction:

Improvecellular DL scheduling reliabilityVSAvoidinterference on PDCCH resource elements

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces DRX cycle configuration as an intermediary mechanism that mediates between cellular and D2D reception requirements. Instead of directly increasing PDCCH resources to compensate for missed scheduling, the DRX intermediary pre-coordinates reception timing to prevent scheduling conflicts. This intermediary layer of time-division management resolves the scheduling reliability issue without requiring additional PDCCH resources, thereby avoiding the harmful side effect of increased interference on control channel elements

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS10129924B2Method of sharing a UE receiver between D2D and cellular operations based on activity

Publication Date: 2018.11.13 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Systems and methods are disclosed for utilizing non-overlapping time periods within one or more Discontinuous Reception (DRX) cycles configured for a Device-to-Device (D2D) capable wireless device for different types of operations. In some embodiments, these different types of operations are cellular and D2D operations such that the D2D capable wireless device performs cellular and D2D operations (e.g., reception of cellular and D2D signals) during non-overlapping time periods during one or more DRX cycles. In this manner, a D2D capable wireless device that, for example, can only receive one type of signal at a time is enabled to receive both cellular and D2D signals.