Power Control Bit Field Reuse for Carrier Aggregation Overhead
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In LTE communication systems, carrier aggregation requires efficient transmission of control information across multiple component carriers, but existing methods face challenges in reducing resource waste and minimizing the burden of blind detection, especially when dealing with varying bandwidths and legacy terminals.
Innovation Solution
Allocate power control bits in a bit field on one physical downlink control channel and use corresponding bits on another channel for conveying hybrid automatic repeat request (H-ARQ) related information, allowing for efficient use of resources and reducing overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate power control bit fields are allocated for each component carrier, then power control information can be transmitted for each carrier, but downlink overhead increases and resource waste occurs
Solution Approach 1:
The patent applies universality by making the power control bit field multi-functional: it can serve as power control information for the first component carrier when only one carrier is assigned, and as H-ARQ resource indication for the second component carrier when multiple carriers are assigned simultaneously. This allows the same bit field to perform different functions based on the scheduling scenario, eliminating the need for separate dedicated bit fields for each component carrier and thereby reducing downlink overhead.
2Quantity of substance
If power control bits are reused for H-ARQ information, then downlink overhead is reduced, but the burden of blind detection increases
Solution Approach 1:
The patent applies dynamics by making the interpretation of the power control bit field dynamic rather than static. The bit field's function changes based on the scheduling condition: it carries power control commands when a single component carrier is assigned, but carries H-ARQ resource indications when multiple component carriers are assigned. This dynamic adaptation allows the system to reduce overhead while managing blind detection complexity through conditional interpretation rather than requiring multiple fixed-format messages.
3Loss of information
If multiple bit fields are allocated for control information on multiple component carriers, then complete control information is provided, but resource efficiency decreases
Solution Approach 1:
The patent applies merging by combining the power control bit field with H-ARQ resource indication functionality in the same bit field location. Instead of allocating separate independent bit fields for power control and H-ARQ information on different component carriers, the patent merges these functions into a single shared bit field that adapts its purpose based on the number of component carriers assigned, thereby improving resource efficiency while maintaining control information completeness.
Data Source
Figure 1~3
Figure 4~6
Figure 7~8
AI summary
Methods and arrangements in a network node and mobile terminal, respectively, in a wireless communication system supporting aggregation of component carriers. The method in a network node involves, when resources on at least two downlink component carriers are being assigned to a mobile terminal at the same time, allocating (908) control information bits not related to power control in a bit field, which is normally used for power control in a message on a physical downlink control channel associated with one of said at least two downlink component carriers. The method in a mobile terminal involves, using control information bits not related to power control obtained from a bit field, which is normally used for power control in a message on a physical downlink control channel associated with one of said at least two downlink component carriers, for locating information related to downlink or uplink transmissions.