PUCCH Resource Allocation for LTE-Advanced Carrier Aggregation
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Solution Overview
Problem
Carrier aggregation in LTE-Advanced systems faces challenges in efficiently transmitting uplink control signaling, leading to higher power consumption and implementation complexity due to the need for multiple uplink component carriers, which is not backward compatible with LTE Rel-8 terminals.
Innovation Solution
A signaling mechanism that allows the transmission of control information on a single uplink component carrier for downlink transmissions on multiple aggregated downlink component carriers, using semi-statically reserved resources and implicit or explicit resource indication, optimizing resource allocation and reducing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If uplink control information is transmitted on multiple uplink component carriers, then control information coverage is improved, but user terminal power consumption increases
Solution Approach 1:
The patent combines control information from multiple downlink component carriers into a single uplink component carrier for transmission. Specifically, ACK/NACK feedback for multiple DL carriers is multiplexed and transmitted on one UL carrier, reducing the number of simultaneous transmissions required and thereby lowering power consumption while maintaining reliable control information delivery.
Solution Approach 2:
The patent creates a universal uplink control channel that can handle control information from multiple downlink carriers. The PUCCH resource on a single UL carrier is designed to accommodate ACK/NACK feedback for any combination of DL carriers, making the transmission system more efficient and reducing the need for multiple dedicated transmission paths.
2Reliability
If uplink control information is transmitted on multiple uplink component carriers, then control information coverage is improved, but implementation complexity increases
Solution Approach 1:
The patent merges the control information transmission function into a single uplink component carrier, consolidating what would otherwise require multiple separate transmission chains. This reduces the complexity of UE implementation by requiring only one PUCCH transmission path instead of multiple parallel paths, while still providing comprehensive control feedback for all DL carriers.
Solution Approach 2:
The patent designs a universal PUCCH resource that can serve multiple DL carriers simultaneously. This multi-functional resource handles ACK/NACK feedback regardless of which DL carriers are active, simplifying the implementation logic and reducing the need for complex carrier-specific configuration and management.
3Reliability
If uplink control information is transmitted on multiple uplink component carriers, then control information coverage is improved, but inter-modulation products increase
Solution Approach 1:
The patent combines control information transmissions into a single uplink carrier, eliminating the need for simultaneous transmissions on multiple UL carriers. This reduces the number of frequency sources that could generate inter-modulation products, thereby reducing harmful interference and improving overall signal quality while maintaining reliable control feedback.
4Productivity
If carrier aggregation with multiple uplink component carriers is used, then bandwidth expansion is achieved, but backward compatibility with LTE Rel-8 terminals is lost
Solution Approach 1:
The patent creates a universal uplink control transmission mechanism that works for both LTE Rel-8 and LTE-Advanced carriers. By consolidating control information transmission on a single UL carrier, the system maintains compatibility with legacy terminals that expect single-carrier behavior, while still supporting aggregated DL carriers for enhanced throughput in LTE-Advanced deployments.
Data Source
AI summary
Systems and methods of signaling uplink control information in a mobile communication network using carrier aggregation are provided. In one exemplary embodiment, a method may include scheduling downlink transmissions to a first user terminal on a single downlink component carrier (CC) associated with a primary cell and scheduling downlink transmissions to a second user terminal on multiple downlink CCs or on a downlink CC associated with a non-primary cell. Further, the method may include receiving, on a first set of radio resources, control information associated with the downlink transmissions to the first user terminal. In addition, the method may include receiving, on a second set of radio resources, control information associated with the downlink transmissions to the second user terminal.