Multi-Carrier Power Control via TPC Index Mapping
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Solution Overview
Problem
In multi-carrier wireless communication networks, existing power control methods struggle to efficiently manage transmit power across multiple component carriers, particularly in asymmetric configurations where the number of uplink carriers exceeds downlink carriers, leading to challenges in conveying and applying Transmit Power Control (TPC) commands effectively.
Innovation Solution
The method involves determining associations between TPC indices and component carriers, using Radio Network Temporary Identifiers (RNTIs) to decode and transmit TPC commands, and adjusting transmit power based on these indices and identifiers to ensure accurate power control across multiple uplink carriers, without requiring changes to downlink control information formats or introducing new formats.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If independent TPC commands are transmitted for each uplink carrier, then power control accuracy is improved, but control information overhead increases
Solution Approach 1:
The patent combines TPC commands for multiple uplink carriers into a single grouped TPC command structure. Instead of transmitting separate TPC commands for each carrier, the base station groups multiple TPC commands together in one downlink transmission, allowing the UE to efficiently receive and process power control instructions for multiple carriers simultaneously, thereby reducing control information overhead while maintaining power control accuracy.
Solution Approach 2:
The grouped TPC command structure serves multiple functions: it provides power control for multiple uplink carriers, supports both asymmetric and symmetric carrier configurations, and maintains compatibility with existing single-carrier power control mechanisms. This multi-functional approach allows the same control structure to handle diverse carrier scenarios without requiring separate specialized commands for each case.
2Productivity
If TPC commands are grouped for multiple carriers, then control information efficiency is improved, but complexity in mapping TPC commands to carriers increases
Solution Approach 1:
The patent segments the grouped TPC commands into individual carrier-specific commands using TPC indices. Each TPC command within the group is associated with a specific uplink carrier through an index value, allowing the UE to systematically map each command to its corresponding carrier. This segmentation approach organizes the complex mapping relationship in a structured manner, making it manageable despite involving multiple carriers.
Solution Approach 2:
The patent uses TPC indices as parameter identifiers to map grouped TPC commands to specific carriers. By changing the parameter representation from direct carrier identification to index-based reference, the system reduces the complexity of command-to-carrier mapping. The indices serve as compact references that the UE can use to efficiently determine which carrier each TPC command applies to.
3Adaptability or versatility
If existing downlink control information formats are used, then compatibility with current standards is maintained, but flexibility in managing asymmetric carrier configurations is reduced
Solution Approach 1:
The patent introduces dynamic carrier indication fields within the existing downlink control information formats. These fields can be adaptively configured to indicate different uplink carriers based on the current transmission context and carrier configuration. The dynamic nature of these fields allows the system to flexibly handle asymmetric carrier configurations while maintaining the overall structure of existing control information formats, avoiding the need for completely new format definitions.
Data Source
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AI summary
Techniques for adjusting transmit power of component carriers in a multi-carrier wireless communication system are disclosed. A base station may determine a plurality of associations relating to one or more component carriers configured for use by a user equipment. The user equipment may receive downlink control information from the base station including one or more power control commands and may adjust a transmit power of its component carriers based on the associations. The user equipment may be notified of the associations either implicitly or explicitly.