LTE Interference Cancellation via Cell-Specific Power Ratio
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Solution Overview
Problem
In Long Term Evolution (LTE) systems, user equipment struggles to effectively cancel interference due to the inability to accurately estimate the power transmission strength of strong interfering cells, leading to significant deviations in interference cancellation performance.
Innovation Solution
Obtaining downlink cell-specific power ratio information of intra-frequency neighboring cells, performing channel estimation for specific physical channels or messages, compensating the channel estimation matrix with this information, and reconstructing received signals to cancel interference caused by strong interfering cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If interference cancellation algorithm is used on user terminal side to directly cancel interference, then interference cancellation capability is provided, but estimation accuracy of interfering cell signal power is insufficient leading to poor cancellation performance
Solution Approach 1:
The patent introduces downlink cell-specific power ratio information as an intermediary parameter that bridges the gap between reference signal power measurement and physical channel power estimation. This intermediary enables accurate interference cancellation without requiring direct measurement of the interfering cell's physical channel power, resolving the contradiction between providing cancellation capability and achieving accurate estimation.
Solution Approach 2:
The patent changes the parameter used for power estimation from direct physical channel power measurement to downlink cell-specific power ratio information derived from reference signals. This parameter transformation enables accurate power estimation while maintaining the ability to cancel interference, effectively resolving the measurement precision issue.
2Ease of operation
If user terminal blindly estimates physical channels, signals, or messages of strong interfering cell, then interference cancellation is attempted, but large deviation occurs during estimation and reconstruction seriously affecting cancellation performance
Solution Approach 1:
The patent incorporates downlink cell-specific power ratio information as feedback that corrects the blind estimation process. This feedback mechanism enables the user terminal to adjust its estimation based on actual power ratio measurements, transforming the blind estimation into an informed process that achieves high accuracy without complex operations.
Solution Approach 2:
The patent performs preliminary measurement and recording of downlink cell-specific power ratio information before the interference cancellation process. This preliminary action provides accurate power ratio data that guides the subsequent estimation and reconstruction, eliminating large deviations while keeping the overall process simple and easy to operate.
Data Source
AI summary
An interference cancellation method, data sending method, apparatus, user equipment and base station in a Long Term Evolution system are disclosed. The interference cancellation method includes: obtaining downlink cell-specific power ratio information of a specific cell; performing channel estimation based on a downlink cell-specific reference signal (CRS) of the specific cell, to obtain a channel estimation matrix of a specific physical channel, signal, or message of the specific cell; compensating the channel estimation matrix by using the downlink cell-specific power ratio information; and canceling, in an original signal that is received from a target cell and is interfered by the specific cell, interference caused by the specific cell in a received signal from a specific physical channel, signal, or message. A technical problem in the prior art that a user equipment cannot effectively cancel interference because power transmission strength of a strong interfering cell cannot be correctly estimated is solved.