Multi-Antenna MLD Circuit Simplification via Shared Signal Points
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Solution Overview
Problem
Current MIMO-AMC systems face challenges in performing efficient spatial-multiplexed signal detection using Maximum Likelihood Detection (MLD) due to the complexity of arithmetic calculations, especially when dealing with combinations of different modulation schemes such as QPSK and 16QAM, which have not been adequately supported by existing MLD receiving apparatuses.
Innovation Solution
A multi-antenna transmitting and receiving apparatus configuration that maps data from different antennas to shared signal points across modulation schemes, allowing for simplified MLD arithmetic calculations by using only signal points shared by modulation schemes, reducing the circuit scale required for MLD in the receiving apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If MLD is performed for all combinations of modulation schemes (e.g., QPSK and 16QAM), then detection accuracy is improved, but arithmetic calculation complexity and circuit scale increase significantly
Solution Approach 1:
The patent merges the signal points of different modulation schemes (QPSK and 16QAM) into a unified set of shared signal points. By combining the signal point spaces, the receiver only needs to perform MLD calculations for the larger 16QAM constellation, which automatically covers all QPSK combinations as well, thereby reducing calculation complexity while maintaining detection accuracy across all modulation scheme combinations.
Solution Approach 2:
The patent creates a universal MLD calculation framework where a single set of shared signal points serves multiple modulation schemes simultaneously. The receiving apparatus uses one unified MLD calculation process that works for all combinations of QPSK and 16QAM, making the system multi-functional and eliminating the need for separate calculation circuits for each modulation combination.
2Reliability
If separate MLD calculation circuits are provided for each modulation scheme combination, then detection capability is improved, but circuit scale and manufacturing complexity increase
Solution Approach 1:
The patent merges multiple separate MLD calculation circuits into a single unified circuit by sharing the signal point space. Instead of providing separate circuits for QPSK-QPSK, QPSK-16QAM, 16QAM-QPSK, and 16QAM-16QAM combinations, the invention uses one circuit that handles all cases through shared signal points, significantly reducing circuit scale while maintaining full detection capability.
Solution Approach 2:
The patent designs a universal MLD calculation circuit that can handle all modulation scheme combinations through a single set of shared signal points. This multi-functional circuit replaces the need for multiple specialized circuits, simplifying manufacturing and reducing hardware complexity while preserving reliable detection across all supported modulation combinations.
3Measurement precision
If all signal points from all modulation schemes are used as candidate signal points, then detection accuracy is improved, but arithmetic calculation time increases
Solution Approach 1:
The patent merges the candidate signal point sets from different modulation schemes into a single shared set. By combining QPSK and 16QAM signal points into one unified constellation, the receiver performs MLD calculations only once using the larger 16QAM signal points, which naturally encompasses all QPSK possibilities, thereby reducing calculation time while maintaining accuracy.
Solution Approach 2:
The patent uses excessive action by employing the larger 16QAM signal points to represent both QPSK and 16QAM combinations. Instead of performing separate calculations for each modulation scheme, the system performs a single calculation using the superset of 16QAM signal points, which provides more than enough resolution to accurately detect all possible combinations, thereby reducing overall calculation time.
Data Source
AI summary
Provided is a multi-antenna transmission device (400) which can perform MLD by using a simple configuration of a reception device in a MIMO-AMC system. The multi-antenna transmission device (400) includes common signal point mapping units (401, 402) for mapping data transmitted from different antennas (111, 112) in transmission scheme using MIMO spatial multiplexing, to common signal points shared by respective modulation methods. Thus, the arrangement of baseband signal points obtained by mapping a code word after channel encoding onto an IQ plane can be shared as common signal points shared by modulation methods. Accordingly, the reception device need not prepare a particular circuit for performing MLD calculation in accordance with a combination of the methods for modulating the signals which have been MIMO-space multiplexed. This can reduce the circuit size of the MLD calculation circuit.