MIMO Precoding Matrix for Mixed Modulation Power Balancing
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Solution Overview
Problem
Current MIMO communication systems face challenges in optimizing data transmission quality and diversity gain due to differences in modulation schemes and power levels between multiple antennas, leading to suboptimal spatial diversity and reception quality.
Innovation Solution
The proposed method involves using a precoding matrix that adjusts the modulation schemes and power levels between two antennas, ensuring that the number of signal points in the I-Q plane for each symbol aligns with the bit data, and maintaining specific power ratios to enhance spatial diversity and data reception quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If different modulation schemes are used between multiple antennas, then data communication rate can be enhanced, but spatial diversity gain deteriorates
Solution Approach 1:
The patent changes the modulation scheme parameters differently for each antenna based on channel conditions. Specifically, it applies different modulation schemes (e.g., QPSK, 16QAM, 64QAM) to signals from different antennas, allowing each antenna to operate at optimal data rates while maintaining overall system diversity through the precoding matrix adjustment.
2Adaptability or versatility
If different power levels are used between multiple antennas, then transmission flexibility is improved, but reception quality deteriorates
Solution Approach 1:
The patent adjusts power levels for each antenna signal through the precoding matrix, allowing different transmission powers to be applied based on channel conditions. This enables flexible power allocation to optimize transmission adaptability while the overall precoding design maintains reception quality by compensating for power differences through appropriate signal weighting and phase adjustment.
Solution Approach 2:
The patent equalizes the average power of composite signals across different antennas through precoding matrix design. By adjusting the precoding weights, it ensures that despite different individual antenna power levels, the composite signal maintains consistent power characteristics, thereby preserving reception quality while allowing transmission flexibility.
3Measurement precision
If modulation schemes are optimized for each antenna, then data reception quality improves, but system complexity increases
Solution Approach 1:
The patent optimizes modulation schemes for each antenna based on channel state information, adjusting parameters such as modulation order and precoding weights to maximize reception quality. The system dynamically selects and applies different modulation and precoding parameters for each antenna, allowing high reception quality while managing complexity through structured parameter optimization.
Data Source
AI summary
In a transmission method according to one aspect of the present disclosure, a encoder performs error correction coding on an information bit string to generate a code word. A mapper modulates a first bit string in which the number of bits is the predetermined integral multiple of (X+Y) in the code word using a first scheme, the first scheme being a set of a modulation scheme in which an X-bit bit string is mapped to generate a first complex signal and a modulation scheme in which a Y-bit bit string is mapped to generate a second complex signal, and modulates a second bit string in which the first bit string is removed from the code word using a second scheme different from the first scheme.