PUCCH Format X for HARQ-ACK and CSI Transmission
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Solution Overview
Problem
Current LTE systems face challenges in efficiently transmitting data acknowledgement signals over a large number of downlink component carriers due to limitations in the capacity of existing PUCCH formats, which cannot convey the necessary amount of uplink control information for up to 32 component carriers.
Innovation Solution
The introduction of a new PUCCH format, referred to as format X, which allows for concurrent transmission of periodic CSI and HARQ-ACK/SR bits, along with resource allocation methods and channel coding schemes to maximize payload size and spectral efficiency, while also enabling conditional suspension or dropping of partial UCI in power-limited cases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If existing PUCCH formats are used for transmitting uplink control information, then device complexity is reduced and ease of operation is maintained, but the capacity to convey acknowledgment signals over a large number of downlink component carriers is insufficient
Solution Approach 1:
The PUCCH format is designed to dynamically adapt its payload capacity based on the number of downlink component carriers configured. The format supports variable-sized payloads that can accommodate up to 32 component carriers, allowing the system to scale control information capacity according to carrier aggregation configuration without requiring multiple fixed-format PUCCH structures.
Solution Approach 2:
The patent changes the parameters of the PUCCH format to support larger payload sizes. Specifically, it modifies the physical uplink control channel to handle increased numbers of HARQ-ACK bits through adjusted modulation schemes, resource allocation, and coding parameters, enabling efficient transmission over extended carrier aggregations.
2Productivity
If the number of downlink component carriers is increased to support wider transmission bandwidths, then data throughput is improved, but the capacity requirements for uplink control information transmission increase beyond existing PUCCH format capabilities
Solution Approach 1:
The enhanced PUCCH format serves multiple functions simultaneously: it transmits HARQ-ACK bits for varying numbers of component carriers, supports both FDD and TDD modes, and accommodates different carrier aggregation configurations (up to 32 CCs). This universal design eliminates the need for separate PUCCH formats for different carrier aggregation scenarios.
Solution Approach 2:
The patent extends the PUCCH capacity by utilizing additional resource dimensions including time-domain resources (slots, subframes), frequency-domain resources (resource blocks), and spatial resources (antenna ports, layers). This multi-dimensional resource allocation enables the single PUCCH format to handle vastly increased control information volumes.
3Productivity
If channel coding schemes are optimized to maximize payload size, then spectral efficiency is improved, but reliability of control information transmission may be compromised
Solution Approach 1:
The patent employs adaptive channel coding parameters including variable coding rates, configurable redundancy versions, and adjustable block lengths that can be optimized for each transmission scenario. These parameter adjustments allow the system to maximize spectral efficiency while maintaining reliability thresholds for control information.
Solution Approach 2:
The system implements feedback mechanisms where the eNB receives the PUCCH transmissions and provides acknowledgments or retransmission requests. This feedback loop enables the system to adapt coding parameters dynamically, ensuring reliable delivery of control information while optimizing spectral efficiency through iterative refinement.
Data Source
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AI summary
Future LTE systems will support massive carrier aggregation that necessitates transmission of a large number of acknowledgement signals (HARQ-ACKs) in response to downlink data transmitted over multiple component carriers. Described herein are methods and apparatus for efficiently transmitting HARQ-ACK and periodic channel state information (P-CSI) bits over the PUCCH (physical uplink control channel).