Pilot Mapping Method for CSI-RS Power Borrowing in LTE
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Solution Overview
Problem
In LTE systems, the simple mapping of channel state information reference signals (CSI-RS) across antenna ports leads to inconsistencies in pilot signal powers, affecting channel estimation quality and coverage due to unequal power distribution among antenna ports.
Innovation Solution
A method for grouping antenna ports into groups and mapping CSI-RS across resource elements in a frequency and time domain grid, allowing for power borrowing between ports to ensure consistent power levels, thereby optimizing power utilization and channel estimation quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the same pilot pattern is used across all PRBs in the system bandwidth, then the mapping of antenna ports is simpler, but a more complex pilot mapping mode cannot be realized and power distribution among antenna ports becomes unequal
Solution Approach 1:
The system bandwidth is divided into multiple sub-bandwidths, and each sub-bandwidth is further divided into multiple PRB groups. Different pilot patterns can be applied to different PRB groups, enabling flexible adaptation while maintaining manageable complexity through structured segmentation.
Solution Approach 2:
Different pilot patterns are applied to different PRB groups within the system bandwidth, allowing each region to have optimized pilot mapping characteristics. This enables power borrowing between antenna ports within specific PRB groups while maintaining overall system flexibility.
2Device complexity
If the same pilot pattern is used across all PRBs, then mapping is simpler, but power distribution among antenna ports becomes unequal affecting channel estimation quality
Solution Approach 1:
By segmenting the bandwidth into PRB groups and applying different pilot patterns to different groups, the system achieves power balance among antenna ports without requiring complete redesign of the mapping structure. Each PRB group can independently optimize power distribution.
Solution Approach 2:
The patent changes the pilot pattern parameters (such as resource element positions and power allocation) across different PRB groups. This allows power borrowing between antenna ports through parameter adjustment rather than structural complexity increase.
3Ease of manufacture
If simple mapping is used, then implementation is easier, but transmission power utilization is not fully optimized
Solution Approach 1:
Different pilot patterns with optimized power allocation are applied to different PRB groups, allowing full utilization of transmission power in each local region. The base station can allocate power dynamically across antenna ports based on channel conditions while maintaining implementation simplicity through standardized pattern structures.
Solution Approach 2:
The patent enables dynamic power allocation across antenna ports by allowing different pilot patterns in different PRB groups. This dynamic adaptation optimizes transmission power utilization while maintaining relatively simple mapping structures that are easy to implement.
Data Source
Figure 1A~2B
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AI summary
The present disclosure provides a pilot mapping method, a pilot signal transmission method and apparatus, a base station and a terminal. In each PRB of one PRB group, the positions at which a pilot of each antenna port is mapped to resource elements (RE) in the PRB is determined according to an antenna port index and an index of the PRB in the PRB group or the whole system bandwidth, so that support is provided for implementation of power borrowing, so as to make full use of transmit power of a base station end, improve the coverage range of the pilot signal and channel estimation quality of a reception end.