Distributed TTI Bundling for Peak Current Limited Uplink
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Peak current limited devices in LTE communication systems face challenges in continuous uplink transmissions due to limited battery and power amplifier capabilities, making it difficult to maintain the uplink timeline and utilize traditional TTI bundling techniques.
Innovation Solution
The implementation of distributed TTI bundling with dynamic bundle size determination, allowing peak current limited user equipment to transmit redundancy versions in non-consecutive sub-frames with a periodicity based on RTT or peak current limitations, and receiving a single ACK/NACK feedback, while the base station dynamically adjusts the bundle size based on channel quality and power characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If peak current limited devices transmit continuously in the uplink, then uplink communication performance is improved, but the device violates its peak current limitation and depletes battery power too quickly
Solution Approach 1:
The patent implements periodic TTI bundling where the UE transmits redundancy versions at periodic intervals rather than continuously. The periodicity is configured based on the UE's peak current limitations, allowing the device to maintain communication performance while adhering to its power constraints. The eNB schedules transmission opportunities at regular intervals, enabling the UE to transmit bundled redundancy versions periodically without violating peak current limits.
Solution Approach 2:
The patent segments the uplink transmission into multiple redundancy versions that are transmitted in separate TTIs rather than a single continuous transmission. This segmentation allows the UE to distribute the transmission load over time, reducing the peak current requirement for each individual transmission while maintaining the overall communication performance through cumulative data delivery.
2Reliability
If peak current limited devices use traditional TTI bundling techniques, then transmission reliability is improved, but the device cannot maintain the uplink timeline due to continuous transmission requirements
Solution Approach 1:
The patent introduces dynamic configuration of the periodicity parameter based on the UE's peak current limitations and the eNB's scheduling capabilities. The system dynamically adjusts the transmission interval to balance between maintaining reliability through sufficient redundancy versions and complying with the uplink timeline. This dynamic adaptation allows the UE to flexibly schedule transmissions that meet both reliability requirements and timeline constraints.
Solution Approach 2:
The patent changes the key parameter from continuous transmission to periodic transmission with configurable interval. By adjusting the periodicity parameter, the system can modify the time between redundancy version transmissions to fit within the uplink timeline while still providing sufficient opportunities for reliable data delivery. This parameter change enables the UE to operate within its peak current limitations without sacrificing timeline compliance.
3Device complexity
If the base station uses fixed bundle size for TTI bundling, then device complexity is reduced, but the system cannot optimize transmission efficiency for varying channel conditions and power characteristics
Solution Approach 1:
The patent implements feedback mechanisms where the UE reports its peak current limitations and channel conditions to the eNB. Based on this feedback, the eNB dynamically determines the optimal bundle size and periodicity for TTI bundling. The feedback loop enables the system to adapt the bundling parameters to current operational conditions, optimizing transmission efficiency without requiring complex local decisions at the UE end.
Solution Approach 2:
The patent transitions from static fixed bundle size to dynamic configurable bundle size. The eNB dynamically determines the bundle size based on real-time channel conditions, UE power characteristics, and network scheduling requirements. This dynamic approach allows the system to optimize transmission efficiency for varying conditions while keeping the UE implementation relatively simple by centralizing the decision logic at the eNB.
Data Source
AI summary
A user equipment (UE) and base station may implement improved communication methods which enable a UE that is peak current limited to perform UL transmissions which are consistent with the UL timeline. A UE that is peak current limited may utilize a new form of distributed TTI (transmit time interval) bundling for improved uplink communication performance. In performing “distributed” TTI bundling, the UE may transmit a plurality of redundancy versions of first information to the base station, wherein the plurality of redundancy versions are transmitted in non-consecutive sub-frames with a periodicity of X ms. After the plurality of redundancy versions of first information are transmitted to the base station, the base station may provide a single acknowledge/negative acknowledge (ACK/NACK) to the UE. A method for dynamically generating and using a bundle size for TTI bundling is also disclosed.