Uplink Shared Channel Pilot Generation for Shortened TTI Orthogonality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is no specific method for data transmission in cases where the transmission time interval (TTI) is shortened in LTE systems, leading to potential demodulation issues with uplink data.
Innovation Solution
An uplink transmission method that involves receiving downlink control channel scheduling information to determine a frequency domain resource for transmitting the uplink shared channel, generating a pilot based on this resource, and transmitting the uplink shared channel and pilot on the determined resource, ensuring orthogonality of demodulation reference signals (DMRS) across different TTIs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the transmission time interval (TTI) is shortened to reduce user plane delay, then the user plane delay performance is improved, but there is no specific method for data transmission leading to potential demodulation issues
Solution Approach 1:
The patent segments the frequency domain resources into basic frequency domain units (containing 12 subcarriers) and generates DMRS independently for each unit. This segmentation allows the system to handle shortened TTI transmissions by creating orthogonal DMRS sequences for different TTIs within the same time slot, enabling reliable demodulation even when TTI is shortened below the traditional 1ms subframe duration.
2Device complexity
If traditional DMRS generation methods are used with shortened TTI, then the transmission structure simplicity is maintained, but the orthogonality of DMRS across different TTIs cannot be ensured
Solution Approach 1:
The patent applies local quality by making the DMRS generation locally adaptive to each basic frequency domain unit. Each unit generates its own DMRS sequence based on its specific resource allocation and TTI index, ensuring orthogonality is maintained locally across different TTIs while allowing flexibility in resource allocation. This local approach preserves transmission structure simplicity while achieving the required orthogonality precision.
Data Source
AI summary
An uplink transmission method and an uplink transmission device are provided. The uplink transmission method includes: receiving a first downlink control channel which carries scheduling information of a first uplink shared channel and determining, based on the scheduling information carried on the first downlink control channel, a first frequency domain resource for transmitting the first uplink shared channel; generating a pilot of the first uplink shared channel based on the first frequency domain resource and a basic frequency domain unit; and transmitting the first uplink shared channel and the pilot on the first frequency domain resource.