OFDM-MIMO Demodulator Reducing Computational Complexity
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Solution Overview
Problem
The existing OFDM-MIMO receiver has high computational complexity, particularly in calculating the equalization matrix, which leads to increased power consumption and cost, making it inefficient for modern broadband high-speed data systems.
Innovation Solution
A demodulation method and demodulator for OFDM-MIMO systems that reduces complexity by using channel estimation values from reference signal sub-carriers to calculate and interpolate equalization matrices for data sub-carriers, thereby simplifying the process and reducing operational calculations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the existing OFDM-MIMO receiver calculates the equalization matrix at each data sub-carrier, then the demodulation accuracy is improved, but the computational complexity and power consumption increase significantly
Solution Approach 1:
The patent calculates the equalization matrix in advance at reference signal sub-carriers before data reception, and stores these pre-calculated matrices. During actual data demodulation, the system retrieves and applies these pre-computed matrices through interpolation rather than recalculating them, significantly reducing real-time computational complexity while maintaining demodulation accuracy
Solution Approach 2:
The patent uses interpolation techniques to generate approximations of the equalization matrix at data sub-carriers based on the pre-calculated values at reference signal sub-carriers. This copying approach creates sufficient estimates for data demodulation without performing the full matrix calculation at every data sub-carrier, thereby reducing computational burden
2Measurement precision
If the existing OFDM-MIMO receiver calculates the equalization matrix at each data sub-carrier, then the demodulation performance is improved, but the power consumption increases
Solution Approach 1:
The equalization matrix is pre-calculated at reference signal sub-carriers before the data transmission phase. This preliminary calculation shifts the computational burden to a phase where power consumption can be managed more efficiently, and the results are reused during data reception, reducing real-time power consumption while maintaining demodulation performance
Solution Approach 2:
The system creates approximate copies of the equalization matrix at data sub-carriers through interpolation based on the pre-calculated reference values. This copying mechanism avoids redundant full calculations at each data sub-carrier, significantly reducing power consumption during data demodulation while preserving adequate performance
3Manufacturing precision
If the existing OFDM-MIMO receiver performs full equalization matrix calculation, then the processing accuracy is improved, but the operational complexity increases
Solution Approach 1:
The patent divides the frequency spectrum into reference signal sub-carriers and data sub-carriers. The equalization matrix is fully calculated only at reference signal sub-carriers, while data sub-carriers use interpolated values from neighboring reference points. This segmentation reduces operational complexity by avoiding full calculations at every sub-carrier while maintaining processing accuracy through selective full calculation and interpolation
Solution Approach 2:
The system generates approximate equalization matrices for data sub-carriers by copying and interpolating from the accurately calculated reference signal sub-carrier matrices. This approach reduces operational complexity by replacing full calculations with lighter interpolation operations while preserving sufficient processing accuracy for data demodulation
Data Source
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AI summary
A demodulation method and a demodulator for an Orthogonal Frequency Division Multiplexing (OFDM)-Multiple Input Multiple Output (MIMO) system are provided, and at first, by using a received reference signal, the channel estimation value at the reference signal sub-carrier in each channel is obtained by estimation; by using the channel estimation value at the reference signal sub-carrier in each channel, an equalization matrix at the reference signal sub-carrier is obtained; by using the obtained equalization matrix to carry out the interpolation calculation, equalization matrixes at all of data sub-carriers are obtained; by using the data signals in various paths received from all of data sub-carriers and corresponding equalization matrixes, an intermediate estimation value of the transmitted data is obtained by calculation; by using a precoding matrix to carry out de-precoding on the intermediate estimation value of the transmitted data, a final estimation value of the transmitted data is obtained. The demodulator comprises an OFDM demodulation module, a frame parsing module, a precoding matrix generation module, a partial channel estimation module, a partial equalization matrix generation module, an equalization matrix interpolation module, a MIMO demodulation module and a de-precoding module. The present invention can reduce the complexity of an OFDM-MIMO receiver.