Uplink Transmission Scheduling for D2D Discovery in Wireless Systems
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Solution Overview
Problem
Device-to-device (D2D) communication in wireless communication systems faces challenges such as interference and the inability of UEs with single transceiver chains to perform simultaneous uplink data transmission and D2D signal monitoring, leading to reduced network efficiency and quality of service.
Innovation Solution
A method that involves determining a time period for D2D discovery signal communication, establishing connections with serving cells, and refraining from transmitting uplink signals during overlapping subframes to minimize interference, allowing for flexible uplink transmission and D2D communication while prioritizing signals and processing physical channels effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a UE with a single transceiver chain performs uplink data transmission during a D2D signal monitoring period, then uplink communication efficiency is improved, but self-interference occurs and D2D signal monitoring fails
Solution Approach 1:
The patent segments the time-frequency resources by introducing a measurement gap concept, where specific subframes are designated for D2D signal monitoring while others are available for uplink data transmission. This segmentation allows the single transceiver chain to alternate between transmission and reception modes without self-interference, resolving the contradiction between uplink efficiency and D2D monitoring capability
Solution Approach 2:
The patent implements dynamic resource allocation where the UE can flexibly switch between uplink data transmission and D2D signal monitoring based on received indicators from the base station. The measurement gap configuration and indication mechanisms enable dynamic adaptation of transmission/reception timing, allowing the system to optimize uplink efficiency while preventing self-interference through real-time control
2Adaptability or versatility
If D2D communication is performed in a licensed band using uplink subframes, then frequency utilization efficiency is improved, but interference with existing LTE signals increases
Solution Approach 1:
The patent introduces measurement gaps as intermediary time periods that mediate between D2D communication and LTE uplink transmission. These gaps act as buffers that prevent direct interference while allowing both services to coexist in the licensed band, maintaining frequency utilization efficiency while protecting LTE signal integrity through controlled time-division isolation
3Adaptability or versatility
If a UE monitors D2D signals and transmits uplink data simultaneously, then communication flexibility is improved, but the UE becomes incapable of performing either operation effectively
Solution Approach 1:
The patent implements periodic action through measurement gap repetition, where D2D signal monitoring occurs at regular periodic intervals defined by the measurement gap configuration. This periodic structure allows the UE to reliably alternate between monitoring and transmission modes, maintaining communication flexibility while ensuring each operation has dedicated time resources for effective execution
Data Source
AI summary
A method of transmitting uplink data is provided. The method includes establishing connections with a first serving cell and a second serving cell, determining, by a user equipment (UE), a time period for a device-to-device (D2D) discovery signal communication via the second serving cell, determining, by the UE and based on an uplink grant received via the first serving cell, a first subframe associated with an uplink signal to an evolved NodeB (eNB) associated with the first serving cell, and in response to determining that the first subframe overlaps in time with the time period, refraining from transmitting the uplink signal in the first subframe, and transmitting, based on a retransmission timing, the uplink signal.