MIMO Terminal Modulation Order Determination via Singular Value Extraction
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Solution Overview
Problem
In multiple-input multiple-output (MIMO) communication systems, determining the modulation order of a modulated signal is challenging due to varying radio wave states and interference, which affects the accuracy of symbol error rate reduction and data transmission.
Innovation Solution
A terminal is equipped with a singular value extractor, modulation order determination unit, and received signal demodulator to calculate and compare Euclidean distances between transmission and received symbols, using singular values from the channel matrix to determine the modulation order and demodulate signals accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the terminal uses adaptive modulation scheme to change modulation scheme according to radio wave state, then data transmission rate is improved, but modulation order determination accuracy deteriorates due to varying channel conditions and interference
Solution Approach 1:
The patent applies preliminary action by calculating singular values of the channel matrix before modulation order determination. The singular value extractor computes singular values from the channel matrix H, and these pre-calculated singular values are then used in the Euclidean distance calculation to determine modulation order. This preliminary extraction of channel characteristics enables accurate modulation order determination despite varying channel conditions.
Solution Approach 2:
The patent uses parameter changes by transforming the channel matrix into singular values through singular value decomposition. Instead of directly using the complex channel matrix, the system extracts singular values (λ1, λ2, ..., λmin(Nt,Nr)) as transformed parameters that capture essential channel characteristics. These singular value parameters are then used to calculate Euclidean distances for modulation order determination, adapting to changing channel conditions.
2Reliability
If the terminal calculates Euclidean distance between transmission and received symbols to determine modulation order, then symbol error rate is reduced, but calculation complexity increases
Solution Approach 1:
The patent applies the taking out principle by extracting only the essential singular values from the full channel matrix. Instead of processing the entire complex channel matrix for modulation order determination, the system extracts singular values (λ1, λ2, ..., λmin(Nt,Nr)) that capture the dominant channel characteristics. This extraction simplifies the Euclidean distance calculation while maintaining accuracy in modulation order determination.
Solution Approach 2:
The patent performs preliminary calculation of singular values before the actual modulation order determination process. The singular value extractor computes the singular values of the channel matrix in advance, and these pre-computed values are then used in the Euclidean distance formula. This preliminary action separates the complex channel characterization from the modulation order decision, reducing overall computational complexity.
Data Source
AI summary
A method of modulating and/or demodulating a signal in a communication system and a terminal for demodulating a signal received from a base station are provided. A terminal includes a singular value extractor to extract at least one singular value of a channel matrix associated with a channel that is formed between a base station and the terminal, a modulation order determination unit to determine a modulation order based on the at least one singular value, and a received signal demodulator to demodulate a received signal according to the determined modulation order.