Terminal Feedback Codebooks for Discontinuous Virtual Carriers
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Solution Overview
Problem
In wireless communication systems, there is a lack of a defined feedback operation for retransmission control in widebands that are discontinuous in the frequency domain, particularly in carrier aggregation scenarios.
Innovation Solution
A terminal is equipped with a receiving unit to receive downlink shared channels in virtual CCs, a control unit to determine feedback information, and a transmitting unit to send uplink control channels, with the control unit constructing a codebook that prioritizes either virtual or actual CCs first.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If carrier aggregation is used to secure wideband data resources, then data transmission capacity is improved, but feedback operation for retransmission control cannot be executed in discontinuous frequency domains
Solution Approach 1:
The patent segments the feedback information into separate codebooks for each component carrier (CC) within the virtual CC. Instead of treating the discontinuous frequency domain as a single unit, the feedback is divided and organized by individual CCs, allowing independent handling of each carrier's acknowledgment information while maintaining overall wideband communication functionality.
Solution Approach 2:
The patent introduces a codebook construction mechanism as an intermediary layer between the physical discontinuous carriers and the feedback transmission system. This codebook structure acts as a mediator that organizes feedback information from multiple discontinuous CCs into a coherent format that can be transmitted through the uplink control channel, enabling feedback operation without requiring continuous frequency allocation.
2Measurement precision
If feedback information is transmitted for each component carrier in virtual CCs, then retransmission control accuracy is improved, but uplink control channel overhead increases
Solution Approach 1:
The patent merges the feedback information from multiple component carriers into a unified codebook structure that is transmitted through a single uplink control channel. By combining individual CC feedbacks into an organized codebook format, the system maintains precise retransmission control for each carrier while reducing the total overhead compared to transmitting separate feedback channels for each CC.
Data Source
AI summary
A terminal includes a receiving unit configured to receive, from a base station, a downlink shared channel in virtual CCs (component carrier) that are discontinuous in a frequency domain and that include a plurality of actual CCs, a control unit configured to determine feedback information related to retransmission control corresponding to the downlink shared channel, and a transmitting unit configured to transmit, to the base station, an uplink control channel including the feedback information in the virtual CCs, wherein the control unit constructs a codebook of the feedback information in an order that prioritizes either the virtual CCs or the actual CCs first and then the other CCs second.