TTI Bundling TBS Selection for PUSCH Medium Data Rate Coverage
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Solution Overview
Problem
The existing TTI bundling method in LTE systems cannot effectively improve the coverage of the physical uplink shared channel (PUSCH) at medium data rates, particularly between 128 kbps and 384 kbps, due to limitations in resource block selection and modulation mode, leading to inadequate data transmission rates.
Innovation Solution
A method and device that select a transport block size (TBS) according to a preconfigured table, allowing for QPSK modulation with a smaller number of resource blocks, enabling data transmission using bundled transmission time intervals (TTIs) to achieve the required rate, which involves selecting data starting from a specific position indicated by RV0 and using a larger TBS value to satisfy the rate requirement during TTI bundling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If TTI bundling is applied with QPSK modulation and RB≤3, then coverage is improved, but data rate is limited to maximum 126 kbps which is insufficient for medium data rate requirements
Solution Approach 1:
The patent changes the parameter configuration by allowing TTI bundling to work with higher RB values (greater than 3) and different modulation modes (not limited to QPSK), while still maintaining coverage improvement. This enables the system to achieve both coverage enhancement and medium data rate requirements simultaneously by adjusting the RB and modulation parameters.
2Productivity
If larger TBS value is used to satisfy medium data rate requirement, then data rate is improved, but coverage improvement through TTI bundling becomes ineffective
Solution Approach 1:
The patent introduces dynamic selection of TBS values based on the specific transmission scenario. The system can dynamically choose appropriate TBS values from a range that satisfies both the medium data rate requirement and the coverage improvement goal, rather than using a fixed large TBS value that would prevent coverage enhancement.
3Productivity
If number of RBs is increased to achieve medium data rate, then data rate is improved, but Turbo coding gain and link budget are reduced
Solution Approach 1:
The patent optimizes the RB parameter by allowing flexible selection within a specific range rather than using fixed high RB values. This enables the system to achieve medium data rates while maintaining lower RB counts that preserve Turbo coding gain and link budget, resolving the contradiction between data rate and energy efficiency.
Data Source
AI summary
The present invention provides a method and a device for data transmission. The method includes: according to a preconfigured second table, selecting a TBS value, where the second table is used for describing a corresponding relationship among a TBS value, the number of RBs and a TBS index, the number of RBs corresponding to the selected TBS value is smaller than or equal to a specific value, a modulation mode corresponding to a TBS index which corresponds to the selected TBS value is QPSK, and the selected TBS value is capable of satisfying the rate requirement required during transmission time interval TTI bundling transmission; and according to the selected TBS value, transmitting data carried by a PUSCH using bundled TTIs. The embodiments of the present invention can improve the coverage at a PUSCH medium data rate.