Hadamard Matrix Subsampling for 5G Sequence Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems, particularly in 5G NR, face challenges in improving sequence design for multiple-access technologies, which affects the capacity and peak-to-average power ratio (PAPR) of sequences used in reference signals and other communication processes.
Innovation Solution
The method involves determining a Hadamard matrix and using a sampling function to generate a set of sequences from the matrix. These sequences are then mapped, modified, and modulated for transmission, utilizing π/2 BPSK modulation to optimize PAPR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sequence design methods are used in wireless communication systems, then the implementation is simple, but the capacity and PAPR performance of sequences are insufficient
Solution Approach 1:
The patent transforms the sequence design problem by changing the mathematical domain from time-domain conventional methods to frequency-domain Hadamard matrix-based methods. By using Hadamard matrices with specific parameters (M×M matrices where M is a power of 2) and applying subsampling techniques, the system achieves improved sequence capacity and PAPR performance while maintaining manageable complexity through systematic parameter selection.
Solution Approach 2:
The patent replaces conventional mechanical/time-domain sequence generation methods with mathematical transformations in the frequency domain. Specifically, it uses Hadamard matrix multiplication and subsampling operations to generate sequences with superior properties, substituting the traditional approach of directly constructing sequences in the time domain.
2Quantity of substance
If sequence length is increased to improve capacity, then the capacity increases, but the PAPR increases which reduces transmission efficiency
Solution Approach 1:
The patent segments the Hadamard matrix into smaller sub-matrices or applies subsampling to generate multiple shorter sequences from a larger Hadamard matrix. This segmentation allows the system to achieve high capacity through diversity of sequences while keeping individual sequence lengths optimized for low PAPR, thus resolving the trade-off between capacity and PAPR.
Solution Approach 2:
The patent transitions from optimizing a single sequence to generating a set of sequences from Hadamard matrices. By moving to the frequency domain and utilizing the mathematical properties of Hadamard matrices, the system achieves capacity through the number of available sequences rather than increasing the length of individual sequences, thereby maintaining low PAPR.
Data Source
Figure 1
Figure 2A~2D
Figure 3
AI summary
The present disclosure relates to methods and devices for wireless communication. Aspects of the present disclosure can determine a matrix or Hadamard matrix associated with signal transmission, the matrix or Hadamard matrix including M rows and M columns. Also, aspects of the present disclosure can determine a sampling function for generating a set of sequences from the matrix or Hadamard matrix. Aspects of the present disclosure can also generate the set of sequences by sampling one of a set of rows or a set of columns based on the determined sampling function. Aspects of the present disclosure can also transmit a signal derived based on at least one sequence of the set of sequences.