Beam-Space MIMO Antenna Modulation for Stable Throughput
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Solution Overview
Problem
The existing MIMO antenna systems face challenges in reducing the size of RF chains while maintaining signal processing performance and increasing throughput, especially with increased electromagnetic coupling and spatial correlation, and they struggle with stable throughput without accurate channel feedback.
Innovation Solution
A beam modulation method is introduced for a beam-space MIMO antenna system, which generates a preparatory beam list, a beam combination table, and a beam modulation rule to map bit data patterns, allowing for stable throughput even without channel feedback by using a larger number of beams than transmission antennas, optimizing beam combinations for low correlation and high power efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of antennas is increased to improve beamforming performance and array gain, then the throughput and beamforming performance are improved, but the electromagnetic coupling and spatial correlation between antennas increase, degrading signal processing performance
Solution Approach 1:
The patent segments the antenna system into active antennas connected to RF chains and passive/parasitic antennas without direct RF connections. This segmentation allows increasing the total number of antennas for better beamforming while avoiding the electromagnetic coupling issues that would arise from connecting RF chains to all antennas. The active antennas handle signal processing while passive antennas provide additional beamforming capability.
Solution Approach 2:
The patent introduces passive antennas as intermediaries between the active antennas and the radiation environment. These passive antennas are coupled to active antennas through electromagnetic coupling but do not have direct RF chain connections, serving as mediators that extend the antenna array capability while avoiding the harmful electromagnetic coupling that would occur with direct connections to all antennas.
2Device complexity
If the size of RF chains is reduced to lower cost and complexity, then the device size and cost are reduced, but the signal processing performance deteriorates due to decreased degrees of freedom
Solution Approach 1:
The passive antennas serve themselves by being energized through electromagnetic coupling from active antennas rather than requiring their own RF chains. This self-service mechanism allows the system to utilize additional antennas for beamforming without increasing the number of RF chains, thereby reducing device complexity while maintaining or improving signal processing performance through the enhanced array capability.
3Productivity
If beamforming technology is improved by increasing the number of antennas, then the array gain and beamforming performance increase, but accurate channel feedback is required which restricts throughput based on channel state and radio resources
Solution Approach 1:
The patent applies partial action by using a subset of beams from a larger prepared beam list based on simple criteria rather than requiring full channel feedback. Instead of selecting beams based on complete channel state information, the system uses partial information (such as basic channel quality indicators) to select from pre-computed beams, reducing the feedback overhead while maintaining good beamforming performance.
4Adaptability or versatility
If a larger number of antennas are used, then the reserve beam dimension increases, but the availability of reserve beam dimension is not fully utilized without appropriate modulation techniques
Solution Approach 1:
The patent transitions from traditional spatial multiplexing to beam-space multiplexing by transforming the signal processing domain. Instead of operating directly in the antenna element domain, the system transforms signals into the beam domain using beamforming vectors, creating an additional dimensional space for signal processing. This beam-space dimension allows full utilization of the reserve beam dimension, enabling multiple data streams to be transmitted simultaneously through different beam combinations, thereby increasing throughput and adaptability.
Data Source
AI summary
Provided is a beam modulation and demodulation method and apparatus based on a beam-space multiple input multiple output (MIMO) antenna system, the beam modulation method including generating a preparatory beam list including a plurality of beams, generating a beam combination table of beam combinations of beams selected from the preparatory beam list, generating a beam modulation rule to map the beam combinations and bit data patterns, and determining a beam combination corresponding to input data from the beam combination table based on the beam modulation rule.