DMRS-Based Feedback Resource Allocation for LTE User Equipment
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Solution Overview
Problem
In LTE systems, a limited number of user equipment (UEs) can be flexibly supported due to inefficient resource utilization, and feedback information from different idle UEs cannot be distinguished from each other, leading to resource waste and unreliable feedback channels.
Innovation Solution
UEs select a demodulation reference signal (DMRS) from a list and send identification information, allowing the base station to determine a unique feedback channel resource based on the DMRS and uplink resource, ensuring flexible support of multiple UEs and distinguishing feedback information using identification scrambling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all UEs send feedback information on a fixed downlink feedback resource, then feedback information can be received, but resource utilization is poor and the quantity of supported UEs is limited
Solution Approach 1:
The patent segments the downlink feedback resources by associating different PHICH resources with different uplink resources. UEs that share uplink resources are assigned different PHICH resources based on their DMRS information, thereby segmenting the feedback channel resources to support multiple UEs simultaneously without conflict.
Solution Approach 2:
The patent introduces a new dimension for resource differentiation by using DMRS information (which was previously only for uplink demodulation) to determine PHICH resource allocation. This adds an additional layer of resource dimension, allowing the system to support more UEs by utilizing the DMRS sequence or group ID as an extra degree of freedom in resource allocation.
2Loss of energy
If multiple UEs share the same uplink resource and DMRS, then resource utilization improves, but feedback information cannot be uniquely determined
Solution Approach 1:
The patent applies local quality by making the PHICH resource allocation specific to each UE's local characteristics (DMRS sequence or group ID). While UEs share the same uplink resource globally, their feedback resources are locally differentiated based on their individual DMRS parameters, ensuring unique feedback information for each UE.
Solution Approach 2:
The patent changes the parameter used for PHICH resource determination from solely uplink resource information to a combination of uplink resource information and DMRS information. This parameter change allows the system to maintain resource sharing while achieving unique feedback allocation through the additional DMRS parameter dimension.
3Quantity of substance
If feedback resources are reserved for multiple UEs, then more UEs can be supported, but resource waste occurs when fewer UEs are active
Solution Approach 1:
The patent implements dynamic resource allocation where PHICH resources are determined at the time of uplink transmission based on the UE's selected DMRS. This dynamic approach allows the system to allocate feedback resources on-demand rather than statically reserving them, thereby supporting variable numbers of active UEs without fixed resource waste.
Data Source
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AI summary
Embodiments of the present invention relate to a communication method, user equipment, and a base station. The method includes: selecting, by user equipment, a DMRS from a demodulation reference signal DMRS list; sending, by the user equipment to a base station through a first channel, first data that carries the DMRS; receiving, by the user equipment through a second channel, second data that is sent by the base station and that carries feedback information, where a resource on which the second channel is located is determined based on the DMRS and a resource on which the first channel is located, or receiving, by the user equipment through a second channel, second data that is sent by the base station and that carries information about a resource on which a third channel is located, where a resource on which the second channel is located is determined based on the DMRS and a resource on which the first channel is located, and receiving, by the user equipment through the third channel, third data that is sent by the base station and that carries feedback information; and determining, by the user equipment, that the feedback information is information fed back by the base station for the first data. In the embodiments of the present invention, feedback information of a plurality of user equipments can be distinguished from each other while resource utilization is ensured.