Grid-Based Reference Signal Transmission for LTE-A Interference Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current LTE-A systems face limitations in supporting a large number of users due to insufficient UERS ports, leading to uncontrolled interference and high reference resource overhead, which affects the reliability of downlink demodulation reference signals.
Innovation Solution
The proposed solution involves dividing the interference space into grids to increase the number of supported users while ensuring controllable and eliminable interference, using a new reference signal transmission method that assigns different grid indexes and port indexes to users, allowing for efficient channel estimation and reduced scheduling complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of UERS ports is increased to support more users, then the number of supported MU users increases, but the reference resource overhead increases and interference becomes uncontrolled
Solution Approach 1:
The interference space is divided into multiple grids, and users are assigned to different grids based on their spatial locations. This segmentation allows the system to support more users by organizing them in a structured manner, reducing the need for excessive reference resources while maintaining interference control through grid-based spatial separation.
Solution Approach 2:
Different grid indexes and port indexes are assigned to users based on their specific spatial locations and interference characteristics. This local differentiation enables precise interference management, where each user group receives customized reference signal configuration suited to their local interference environment, thereby supporting more users without proportionally increasing overall reference resource overhead.
2Reliability
If orthogonal resources are used to transmit UERS of different ports, then interference between ports is avoided, but the reference resource overhead becomes rather large
Solution Approach 1:
The system transitions from relying solely on orthogonal resources (time-frequency-code domains) to incorporating a spatial dimension through grid-based user classification. By assigning users to different grids and using grid indexes as an additional dimension for reference signal differentiation, the system achieves interference avoidance without requiring complete orthogonality in traditional domains, thereby reducing reference resource overhead.
Solution Approach 2:
The invention changes the parameter space by introducing grid indexes as a new dimension for reference signal configuration. Instead of only varying time, frequency, or code parameters to achieve orthogonality, the system now varies the grid index parameter to differentiate users spatially, enabling more efficient resource utilization while maintaining interference avoidance.
3Reliability
If interference control mechanisms are implemented, then transmission reliability improves, but scheduling complexity increases
Solution Approach 1:
The interference space segmentation into grids provides a structured framework that simplifies interference management. By organizing users into discrete grid groups, the scheduling algorithm can systematically assign grid indexes and port indexes according to predefined rules, reducing the complexity of interference control compared to handling arbitrary user configurations without such structure.
Solution Approach 2:
The introduction of grid indexes as a configurable parameter enables flexible yet systematic interference control. The scheduling algorithm can adjust grid index assignments based on user locations and interference conditions, providing reliable interference management through parameter optimization rather than complex algorithmic processing, thereby balancing reliability and complexity.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present application provide a reference signal transmitting method, including: notifying a User Equipment (UE) of a grid index and a reference signal port index of the UE, wherein a coverage area of a base station is divided into grids, the grid index of the UE is an index of a grid where the UE is located; generating a reference signal based on the grid index; and transmitting the reference signal on corresponding time-frequency resources based on the grid index and the reference signal port index. The present application further provides a corresponding reference signal transmitting apparatus, a reference signal receiving method and apparatus, and a scheduling method and apparatus. According to the technical solution provided by the present application, it is possible to increase the number of ports that the system can support at the same time with low reference resource overhead, and to ensure that the interference of the reference signal is controllable and eliminable, thereby ensuring transmission reliability.