MIMO-FBMC Precoding Boundary Interference Cancellation
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Solution Overview
Problem
In MIMO-FBMC systems, interference between precoding code blocks at time-frequency critical locations cannot be effectively canceled due to non-orthogonality and changes in precoding, which complicates channel equalization and reduces signal quality.
Innovation Solution
The method involves canceling interference from symbols at the boundary between precoding code blocks by determining and adding an interference offset or constructing a precoding matrix to eliminate interference, and reserving guard bands to prevent mutual interference, ensuring that the received signal is free or minimized from interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If precoding is introduced in MIMO-FBMC system, then system performance is improved, but interference between precoding code blocks at time-frequency critical locations cannot be canceled
Solution Approach 1:
The patent applies preliminary action by performing interference pre-cancellation before the actual data transmission. Specifically, the receiver estimates the interference from adjacent precoding code blocks based on channel state information and subtracts this estimated interference from the received signal before equalization and detection. This preliminary interference removal enables the system to maintain high signal quality while using precoding technology.
2Device complexity
If simple real-imaginary separation method is used for interference cancellation, then processing complexity is reduced, but interference can only be canceled when channel is flat
Solution Approach 1:
The patent changes the fundamental approach from simple real-imaginary separation to a more sophisticated interference pre-cancellation method that uses channel state information and estimated interference subtraction. This parameter change in the processing method enables the system to handle non-flat channels effectively while maintaining reasonable processing complexity through efficient interference estimation and subtraction algorithms.
3Object-generated harmful factors
If guard bands are reserved to prevent mutual interference, then interference is reduced, but spectral efficiency is lowered
Solution Approach 1:
The patent extracts and removes the harmful interference component from the received signal through interference pre-cancellation, rather than using guard bands to isolate signals. By explicitly identifying and subtracting the interference from adjacent precoding code blocks based on channel state information, the system eliminates interference without requiring spectral guard bands, thereby maintaining high spectral efficiency.
Data Source
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AI summary
The present invention provides a signal sending method and a signal sending device, where the signal sending method includes: canceling interference from symbols of a boundary between at least two precoding code blocks in a multiple input multiple output filter bank multicarrier MIMO-FBMC system, where the precoding code block includes at least one time-frequency resource element that uses same precoding; performing precoding on a to-be-sent symbol in the precoding code block to obtain a precoded symbol; and sending the precoded symbol. In the present invention, mutual interference between precoding code blocks at a time-frequency critical location can be completely or partially canceled.