Subframe Position Determination in NB-IoT
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for determining the positions of start and end subframes in NB-IoT scenarios, such as NPDCCH and NPDSCH, face significant challenges due to large calculation amounts and complex operations, with no effective solutions previously proposed to address these issues.
Innovation Solution
A method and apparatus for determining the start and end subframe positions by calculating static and semi-static intervals, identifying invalid and valid subframes, and utilizing preconfigured maximum repetitions to simplify the calculation process, thereby reducing the computational burden and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the maximum number of repetitions is set to 2048 to achieve coverage enhancement, then the coverage capability is improved, but the calculation amount for determining subframe positions becomes excessively large
Solution Approach 1:
The patent segments the search space into multiple candidate groups, where each group contains a limited number of candidate subframe positions. Instead of calculating all 2048 repetitions sequentially, the system divides them into manageable groups (e.g., first candidate group, second candidate group), allowing the terminal to determine subframe positions within each group independently. This segmentation reduces the computational burden at any given moment while maintaining the ability to handle the full repetition range.
Solution Approach 2:
The patent performs preliminary configuration of search space parameters and candidate subframe positions before actual data transmission. The network configures the maximum number of repetitions, subframe offsets, and other parameters in advance, allowing the terminal to pre-calculate or pre-identify candidate subframe positions. This preliminary action reduces the real-time calculation amount when the terminal needs to determine actual subframe positions for NPDCCH or NPDSCH.
2Reliability
If the maximum delay time is configured to 128 and maximum repetitions to 2048, then the downlink coverage is enhanced, but the calculation complexity for determining NPDSCH subframe positions increases significantly
Solution Approach 1:
The patent segments the delay time range and repetition count into manageable candidate groups. Instead of calculating the end subframe position by iterating through all 2048 repetitions and 128 delay times, the system divides these into candidate groups with predefined subframe offsets. The terminal can efficiently determine the NPDSCH subframe position by selecting from these pre-segmented candidates, significantly reducing calculation complexity.
Solution Approach 2:
The patent introduces new parameters such as subframe offsets, candidate group indices, and candidate quantities to replace the direct calculation method. By changing the representation parameters from absolute subframe positions to relative offsets and group indices, the system simplifies the calculation process. The terminal uses these transformed parameters to efficiently determine subframe positions without performing complex iterative calculations.
3Measurement precision
If traditional methods are used to calculate end positions based on starting points, then accuracy is maintained, but the operation time and power consumption increase
Solution Approach 1:
The patent performs preliminary configuration of candidate subframe positions and search space parameters before actual position determination is needed. The network configures subframe offsets, candidate group indices, and other parameters in advance, allowing the terminal to quickly determine positions without performing complex real-time calculations. This maintains accuracy while reducing operation time.
Solution Approach 2:
The patent uses candidate subframe positions as simplified representations (copies) of the actual subframe positions. Instead of calculating exact positions through complex formulas, the system uses pre-defined candidate positions with offsets that closely approximate the true positions. This copying approach maintains sufficient accuracy for practical purposes while dramatically reducing calculation time and power consumption.
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
Provided are a subframe position determination method and apparatus, a storage medium, and an electronic apparatus. The subframe position determination method includes: determining static intervals and semi-static intervals of a search space corresponding to a current subframe according to a position of the current subframe; determining a number of invalid subframes in the static intervals and the semi-static intervals, and determining a number of valid subframes in the static intervals and the semi-static intervals according to the number of invalid subframes; and determining a start subframe position and an end subframe position corresponding to the position of the current subframe according to the number of invalid subframes and the number of valid subframes.