OFDM Signal Processing Using Frequency Selective Constraint Matrix
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Solution Overview
Problem
Existing MIMO systems using OFDM technology face challenges due to frequency selective fading, as constraint matrices calculated for flat fading channels are not applicable, leading to interference and distortion in OFDM symbol transmission.
Innovation Solution
A signal processing method and apparatus that calculates a constraint matrix based on frequency selective fading channel characteristics, setting the channel matrix to a diagonal matrix and using a confederate matrix for resource element mapping and frequency-time domain transformation to preprocess the input signal, thereby reducing interference and improving processing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a constraint matrix is calculated according to a flat fading channel characteristic, then the preprocessing is simple and efficient, but the constraint matrix is not applicable to OFDM symbols affected by frequency selective fading
Solution Approach 1:
The patent changes the parameter basis for constraint matrix calculation from flat fading channel characteristics to frequency selective fading channel characteristics. Specifically, it uses channel frequency response information across different subcarriers to construct the constraint matrix, making it adaptable to frequency selective fading conditions while maintaining processing efficiency through structured matrix operations.
2Device complexity
If a constraint matrix is calculated according to a flat fading channel characteristic, then the calculation is simple, but the OFDM symbol cannot be preprocessed effectively, leading to interference and distortion
Solution Approach 1:
The patent changes the calculation basis from flat fading channel parameters to frequency selective fading channel parameters. It uses channel frequency response information H(f) across different subcarriers to construct the constraint matrix, enabling effective preprocessing that compensates for frequency-selective effects and reduces interference and distortion in OFDM symbol transmission.
Solution Approach 2:
The patent introduces a frequency-selective constraint matrix as an intermediary element that mediates between the input signal and the OFDM symbol transmission. This matrix serves as a preprocessing tool that compensates for frequency-selective fading effects, improving transmission reliability without significantly increasing system complexity.
3Reliability
If frequency selective fading affects OFDM symbol transmission, then the channel characteristics become more complex, but using a flat fading constraint matrix leads to interference and distortion
Solution Approach 1:
The patent addresses frequency selective fading by changing the constraint matrix construction to use frequency-domain channel response parameters H(f) instead of flat fading parameters. This allows the system to adapt to complex channel characteristics while maintaining a structured processing approach that doesn't excessively increase implementation complexity.
Data Source
AI summary
The present invention discloses a signal processing method and apparatus, and pertains to the field of communications technologies. The apparatus includes: a processor and a memory. The method includes: setting each sampling point signal on an orthogonal frequency division multiplexing OFDM symbol, and obtaining an input signal; calculating a constraint matrix according to a frequency selective fading channel characteristic; and calculating an output signal according to the sampling point signal, the input signal, and the constraint matrix. The present invention resolves a problem that frequency selective fading has an impact on transmission of the OFDM symbol, and a constraint matrix obtained according to a flat fading channel characteristic is not applicable to the OFDM symbol, thereby achieving an effect of reducing the impact of the frequency selective fading on the transmission of the OFDM symbol.