ACK/NACK Feedback via DCI in LTE Control Channels
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Solution Overview
Problem
In LTE systems, the feedback of ACK/NACK information through Physical Hybrid Auto Repeat Request (ARQ) Indicator Channels (PHICH) occupies the entire system bandwidth, leading to poor flexibility and inefficient resource utilization.
Innovation Solution
The ACK/NACK information is carried in Downlink Control Information (DCI), allowing it to be transmitted on either the entire system bandwidth or part of it, enabling flexible feedback without the need for an independent PHICH channel, thereby improving resource utilization and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ACK/NACK information is transmitted through PHICH channel, then feedback reliability is ensured, but system bandwidth occupation increases and flexibility decreases
Solution Approach 1:
The patent merges the ACK/NACK feedback function with the existing PDCCH downlink control channel. Instead of using a separate PHICH channel, the feedback information is embedded in DCI formats (specifically DCI format 1A/1B/1C/1D with a specific RNTI), combining multiple control functions into a unified channel structure that improves resource efficiency while maintaining reliability through existing robust control channel mechanisms.
Solution Approach 2:
The PDCCH channel is designed to serve multiple purposes: traditional downlink control signaling and ACK/NACK feedback transmission. By making the control channel universal, the system eliminates the need for dedicated PHICH resources while maintaining feedback capability, thereby improving bandwidth utilization and providing flexible resource allocation across different terminal types and scenarios.
2Reliability
If PHICH channel is used for ACK/NACK feedback, then feedback coverage is guaranteed, but resource utilization efficiency decreases
Solution Approach 1:
The patent combines ACK/NACK feedback transmission with existing PDCCH resources, merging previously separate functions into a unified control channel. This eliminates dedicated PHICH resource requirements while ensuring feedback coverage through the robust, widely-dispersed PDCCH structure that already provides system-wide coverage.
Solution Approach 2:
The patent extracts the ACK/NACK feedback function from the dedicated PHICH channel and relocates it to the PDCCH structure. This extraction allows the system to eliminate redundant dedicated feedback resources while maintaining comprehensive feedback coverage through the more efficient PDCCH resource allocation mechanism.
Data Source
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AI summary
The embodiments of the present disclosure provide an Acknowledge (ACK)/Not Acknowledge (NACK) information feedback method, a terminal device and a network side device. The method includes that: a terminal device sends uplink data to a network side device; the terminal device receives first Downlink Control Information (DCI) sent by the network side device, the first DCI including ACK/NACK information corresponding to the uplink data; and the terminal device determines the ACK/NACK information corresponding to the uplink data according to the first DCI. In the embodiments of the present disclosure, the ACK/NACK information is carried in the DCI, thereby increasing a resource utilization rate.