Precoding Weight Matrix Hopping for MIMO Reception Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing MIMO systems experience degradation in reception quality as the Rician factor increases in Line of Sight (LOS) environments, particularly in spatial multiplexing MIMO systems used for broadcast or multicast communication.
Innovation Solution
A precoding method that involves selecting one precoding weight matrix from a plurality of predetermined matrices by regularly hopping between them, and generating precoded signals by multiplying the selected matrix with signals based on a selected modulation scheme. The precoding weight matrices are designed to improve reception quality in LOS environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If spatial multiplexing MIMO system is used to increase transmission speed, then transmission speed is improved, but reception quality deteriorates as Rician factor increases in LOS environment
Solution Approach 1:
The patent applies dynamics by making the precoding matrix variable over time through regular hopping between multiple predetermined precoding matrices. This time-varying precoding approach adapts to the LOS channel conditions by switching between different precoding configurations, thereby maintaining both high transmission speed and reception quality in environments with high Rician factors
Solution Approach 2:
The patent changes the parameters of the precoding matrix by using a set of predetermined precoding matrices with different configurations. The receiving device selects appropriate precoding matrices from this set based on channel conditions, particularly optimizing for LOS environments with high Rician factors, thus resolving the contradiction between transmission speed and reception quality
2Reliability
If precoding matrix is fixed to optimize for LOS environment, then reception quality in LOS environment is improved, but adaptability to different propagation environments deteriorates
Solution Approach 1:
The patent achieves universality by designing a precoding matrix set that can effectively serve multiple propagation environments. The predetermined precoding matrices are configured to provide optimal performance across different channel conditions including LOS and NLOS environments, allowing the system to maintain high reception quality regardless of the specific propagation environment
Solution Approach 2:
The patent employs periodic action through regular hopping between multiple precoding matrices. This periodic switching ensures that the system periodically samples different precoding configurations, allowing it to adapt to varying channel conditions while maintaining optimized performance for LOS environments with high Rician factors
Data Source
AI summary
Disclosed is a transmission scheme for transmitting a first modulated signal and a second modulated signal over the same frequency at the same time. According to the transmission scheme, a precoding weight multiplying unit multiplies a baseband signal after a first mapping and a baseband signal after a second mapping by a precoding weight and outputs the first modulated signal and the second modulated signal. In the precoding weight multiplying unit, precoding weights are regularly hopped.