Uplink Control Information Transmission in Multi-Carrier Systems
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Solution Overview
Problem
In LTE systems with carrier aggregation, the limited capacity of the physical uplink control channel (PUCCH) restricts the simultaneous transmission of HARQ-ACK information and periodic CSI, affecting the accuracy of downlink data scheduling, especially when multiple carriers are aggregated, as the UE can only feed back periodic CSI from a maximum of one carrier in an uplink subframe.
Innovation Solution
The method involves dynamically determining the bit quantity or piece quantity of periodic CSI that can be sent based on first indication information from the network device, allowing for adaptive encoding and resource allocation to ensure the transmission performance of HARQ-ACK information while maximizing the amount of periodic CSI sent, by using convolutional coding and adjusting code rates according to channel conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE feeds back periodic CSI of a maximum of one carrier in one uplink subframe to ensure transmission performance of HARQ-ACK information, then the transmission reliability of HARQ-ACK information is improved, but the measurement precision of channel state information for multiple carriers deteriorates
Solution Approach 1:
The patent segments the periodic CSI reporting into multiple parts corresponding to different carriers. The UE determines a first quantity of bits for periodic CSI of a first carrier and a second quantity of bits for periodic CSI of a second carrier, allowing selective reporting of CSI from multiple carriers rather than limiting to one carrier. This segmentation enables the system to maintain HARQ-ACK transmission reliability while improving CSI measurement precision for multi-carrier scheduling.
2Productivity
If the PUCCH capacity is increased to send UCI information of multiple carriers simultaneously, then the productivity of uplink control information transmission is improved, but the device complexity increases
Solution Approach 1:
The patent implements a dynamic bit quantity determination mechanism where the UE adaptively determines the number of bits to report for periodic CSI based on system conditions and carrier configurations. Rather than requiring a fixed high-capacity PUCCH format, the dynamic adjustment of reported bit quantities allows the system to achieve multi-carrier CSI reporting productivity while avoiding the complexity of permanently deploying higher-capacity PUCCH formats. The base station configures maximum bit quantities, and the UE dynamically adapts its reporting within these constraints.
Data Source
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Figure 3
AI summary
Embodiments of the present invention provide a method for transmitting uplink control information and an apparatus, applicable to a multi-carrier system. A user terminal receives physical layer signaling from a network device, where the physical layer signaling includes first indication information; the user terminal determines, according to the first indication information, a bit quantity of periodic CSI that can be sent on the channel resource or a piece quantity of periodic CSI that can be sent on the channel resource; the user terminal determines, according to the bit quantity or the piece quantity of the periodic CSI that can be sent, to-be-sent periodic CSI from periodic CSI corresponding to the multiple downlink carriers; and the user terminal sends HARQ-ACK information and the to-be-sent periodic CSI on the channel resource. According to solutions of the embodiments of the present invention, on the premise that transmission performance of the HARQ-ACK information is ensured, as much periodic CSI as possible can be sent, so that accuracy in scheduling the user terminal by a base station is ensured to the greatest extent possible.