Uplink Control Power Scaling in Multi-Cell Wireless Systems
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Solution Overview
Problem
In wireless communication systems, particularly in Evolved Universal Terrestrial Radio Access Networks (E-UTRAN), the existing methods for handling uplink (UL) control information face challenges in power management and capacity when multiple small cells are densely deployed, leading to potential PUCCH capacity problems and increased loading between eNBs due to limited power allocation for UL control information transmission.
Innovation Solution
The method involves configuring User Equipment (UE) with multiple serving cells and transmitting UL control information on both PUCCH and PUSCH channels, prioritizing power allocation based on the types of control information, such as HARQ-ACK, CSI reports, and Scheduling Requests, to manage power distribution across different serving cells and groups, ensuring efficient power usage and reducing the load on macro cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple serving cells are configured for UE in densely deployed small cell networks, then network capacity and data throughput are improved, but uplink control information transmission reliability deteriorates due to power allocation conflicts and PUCCH capacity limitations
Solution Approach 1:
The patent segments uplink control information into different types (Type 1: HARQ-ACK, Type 2: CSI, Type 3: Scheduling Request) with different power priorities. This segmentation allows the system to differentiate and prioritize critical control information, ensuring that high-priority information maintains transmission reliability even when total power is limited, thus resolving the contradiction between network capacity expansion and control information reliability
Solution Approach 2:
The patent introduces power priority parameters to characterize different types of uplink control information and implements dynamic power scaling based on these parameters. By changing the power allocation parameters dynamically according to information type and channel conditions, the system can maintain reliability for critical information while allowing non-critical information to be scaled down, thus resolving the power allocation conflict in multi-cell scenarios
2Productivity
If UE transmits uplink control information on multiple serving cells simultaneously, then control information delivery capability is improved, but power consumption increases and may exceed maximum power limits
Solution Approach 1:
The patent implements dynamic power scaling where the UE adjusts transmit power in real-time based on the types of control information being transmitted and current channel conditions. The power scaling factor is dynamically calculated to ensure total power does not exceed P_CMAX while prioritizing high-priority information. This dynamic adjustment allows the UE to maintain high control information delivery capability when needed while reducing power consumption when conditions allow, thus resolving the contradiction between delivery capability and power consumption
3Ease of operation
If power is allocated equally to all uplink control information, then fairness is improved, but transmission efficiency deteriorates due to inability to prioritize critical control information
Solution Approach 1:
The patent applies local quality by assigning different power priorities to different types of uplink control information based on their criticality. Type 1 (HARQ-ACK) receives highest priority, Type 2 (CSI) receives medium priority, and Type 3 (Scheduling Request) receives lowest priority. This differentiated local quality approach ensures that critical information receives sufficient power for reliable transmission while non-critical information can be transmitted with lower power or deferred, thus resolving the contradiction between fairness and transmission efficiency
Data Source
AI summary
A method and apparatus are disclosed to handle UL information. The method includes configuring a UE (User Equipment) with multiple serving cells. The method further includes transmitting, from the UE, in a subframe i a first UL control information on a physical channel of a first UL serving cell. The method also includes transmitting, from the UE, in the subframe i a second UL control information on a physical channel of a second UL serving cell, wherein if the total transmit power of the UE exceeds {circumflex over (P)}CMAX (i), the UE would scale down the transmit power of the physical channel with lower power priority based on types of the first UL control information and the second UL control information.