Carrier Aggregation Control Information Transmission via Primary Component Carrier
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication networks face challenges in efficiently transmitting control information across multiple component carriers (CCs) with different uplink-downlink configurations, leading to unschedulable subframes and reduced peak data rates due to asymmetric configurations.
Innovation Solution
The method involves configuring a primary CC (PCC) and secondary CCs (SCCs) for carrier aggregation, where control information is sent on the PCC based on the PCC's HARQ timeline, allowing data transmission on SCCs even when their configurations differ, using cross-subframe scheduling and same-carrier scheduling to align control and data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If control information is transmitted based on each CC's own HARQ timeline, then the transmission timing is optimized for each carrier, but scheduling conflicts occur and subframes become unschedulable when CCs have asymmetric uplink-downlink configurations
Solution Approach 1:
The patent merges the control information transmission for multiple CCs onto a single PCC, using the PCC's HARQ timeline for all control transmissions. This unifies the scheduling mechanism across carriers with different configurations, eliminating timing conflicts while maintaining efficient data transmission on all CCs.
Solution Approach 2:
The PCC acts as an intermediary carrier that mediates control information transmission for both itself and SCCs. By using the PCC's HARQ timeline as a common reference, the system resolves scheduling conflicts between CCs with asymmetric uplink-downlink configurations, making previously unschedulable subframes schedulable.
2Adaptability or versatility
If multiple CCs with different uplink-downlink configurations are configured, then carrier aggregation capacity is increased, but the number of unschedulable subframes increases due to configuration asymmetry
Solution Approach 1:
The PCC serves multiple functions: it acts as a control information carrier for itself and for all SCCs, and provides a universal HARQ timeline that all CCs reference for scheduling. This multi-functional role of the PCC enables the system to handle diverse CC configurations without losing subframes to scheduling conflicts.
3Productivity
If control information for SCCs is transmitted on the PCC using the PCC's HARQ timeline, then scheduling conflicts are resolved and peak data rates improve, but the control information must be multiplexed on a single carrier
Solution Approach 1:
The control information is segmented by function and CC association, with each DCI message clearly indicating which CC it schedules. This segmentation approach, combined with transmission on the PCC, resolves scheduling conflicts while maintaining manageable complexity through structured organization of control messages.
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
Techniques for sending control information to support operation on multiple component carriers (CCs) are disclosed. A user equipment (UE) may be configured with multiple CCs for carrier aggregation. The multiple CCs may be associated with different uplink-downlink configurations and may have different downlink subframes and uplink subframes. In one aspect, uplink control information (UCI) for a secondary CC (SCC) may be sent on a primary CC (PCC) based on a UCI transmission timeline for the PCC (and not based on a UCI transmission timeline for the SCC). For example, a downlink grant for the SCC may be sent based on a downlink grant transmission timeline for the PCC. In another aspect, uplink grants for an SCC may be sent on the PCC based on an uplink grant transmission timeline for the PCC (and not based on an uplink grant transmission timeline for the SCC).