MIMO Transmission Signal Point Arrangement for LOS Reception Quality
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Solution Overview
Problem
MIMO transmission systems face degradation in reception quality, particularly in LOS environments, due to the stabilization of propagation environments, which affects broadcasting and multi-cast communications, where conventional methods fail to maintain reception quality even with high radio wave intensity.
Innovation Solution
The proposed method involves a transmission scheme that maps signals using different 16QAM, 64QAM, and 256QAM mapping methods in an in-phase I-orthogonal Q plane, increasing the probability of minimum Euclidean distance at signal points, thereby improving data reception quality in both NLOS and LOS environments by optimizing signal point arrangements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional MIMO transmission is used, then data communication rate is enhanced, but reception quality degrades in LOS environments
Solution Approach 1:
The patent applies dynamics by making the mapping scheme changeable over time. Specifically, the system switches between different mapping schemes (e.g., first mapping scheme and second mapping scheme) based on propagation environment conditions. In LOS environments, one mapping scheme is used, while in NLOS environments, another mapping scheme is applied. This dynamic adaptation allows the system to maintain both high data communication rates and good reception quality by optimizing the mapping scheme according to current channel conditions.
2Productivity
If signal points are arranged closely to increase data rate, then productivity improves, but manufacturing precision of signal detection deteriorates
Solution Approach 1:
The patent applies local quality by using different mapping schemes with different signal point arrangements for different propagation environments. In LOS environments, a mapping scheme with larger minimum Euclidean distances is used to ensure reliable detection. In NLOS environments, a different mapping scheme is applied that is optimized for those conditions. This allows each local environment to have the appropriate signal point arrangement, maintaining both high data rates and accurate detection where needed.
Solution Approach 2:
The patent applies parameter changes by modifying the mapping scheme parameters (signal point arrangements) based on propagation environment conditions. The system changes the minimum Euclidean distance parameter and signal point configuration according to whether the environment is LOS or NLOS. This parameter adaptation enables the system to optimize both data transmission rate and signal detection precision for each specific environment.
Data Source
AI summary
A transmission method includes mapping processing, phase change processing, and transmission processing. In the mapping processing, a plurality of first modulation signals and a plurality of second modulation signals are generated using a first mapping scheme, and a plurality of third modulation signals and a plurality of fourth modulation signals are generated using a second mapping scheme. In the phase change processing, a phase change is performed on the plurality of second modulation signals and the plurality of fourth modulation signals using all N kinds of phases. In the transmission processing, the first modulation signals and the second modulation signals are respectively transmitted at a same frequency and a same time from different antennas, and the third modulation signals and the fourth modulation signals are respectively transmitted at a same frequency and a same time from the different antennas.