Half-Duplex Device Scheduling via Subframe Offset
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Solution Overview
Problem
In 3GPP LTE and LTE-A systems, half-duplex devices face challenges in efficiently using radio resources due to the assumption of full-duplex capability, leading to increased scheduling overhead, especially when a large number of half-duplex devices are served by a single base station.
Innovation Solution
A method for a half-duplex device in a Frequency Division Duplex (FDD) system that involves receiving downlink control information in a first subframe and transmitting uplink data in a second subframe, with the second subframe spaced apart by an offset value from the first subframe, and optionally retransmitting uplink data in a fourth subframe based on a retransmission request, to reduce scheduling complexity and improve resource allocation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a base station schedules radio resources for half-duplex devices in FDD systems assuming full-duplex capability, then the devices can operate with low hardware complexity and low price, but the scheduling overhead increases significantly
Solution Approach 1:
The patent segments the scheduling process by introducing separate uplink grant indications and downlink assignment indications in the physical downlink control channel. This segmentation allows the base station to independently manage uplink and downlink resource allocation for half-duplex devices, reducing the complexity of coordinated scheduling while maintaining efficient resource utilization.
Solution Approach 2:
The patent applies preliminary action by pre-configuring uplink resources for half-duplex devices before downlink transmissions. The base station sends uplink grants in advance, allowing devices to prepare and transmit uplink data in predetermined subframes, thereby avoiding complex real-time scheduling decisions and reducing overhead.
2Productivity
If uplink transmission and downlink reception are performed at the same time, then communication efficiency is improved, but half-duplex devices cannot perform this operation
Solution Approach 1:
The patent introduces dynamic scheduling mechanisms that adapt resource allocation based on the half-duplex capability of devices. The base station dynamically adjusts uplink and downlink resource assignments in different subframes, optimizing communication efficiency for half-duplex devices while maintaining flexibility to serve full-duplex devices when needed.
Solution Approach 2:
The patent implements periodic action through time-division patterns where half-duplex devices alternate between uplink transmission periods and downlink reception periods. This periodic structure allows the system to achieve high communication efficiency by systematically organizing transmissions in time slots, ensuring that half-duplex devices operate within their capability constraints.
3Area of stationary object
If the number of half-duplex devices served by a single base station increases, then network coverage is improved, but the scheduling overhead problem becomes serious
Solution Approach 1:
The patent creates a universal scheduling framework that can handle both half-duplex and full-duplex devices through the same physical downlink control channel structures. The uplink grant indications and downlink assignment indications are designed to be universally applicable, allowing the base station to efficiently manage a mixed population of devices with different duplex capabilities without requiring separate scheduling mechanisms.
Data Source
AI summary
A method for transmitting data for a half-duplex device in a wireless communication system is provided. The half-duplex device receives first downlink control information from a base station in a first subframe. The half-duplex device transmits uplink data to the base station in a second subframe. The first downlink control information includes a resource through which the uplink data is transmitted and information on the second subframe.