MIMO AMC Optimization via SIC Ordering and CQI Feedback
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Solution Overview
Problem
MIMO systems face challenges in simultaneously achieving high transmission data rate and diversity gain due to errors in channel feedback and the impracticality of applying adaptive modulation and coding (AMC) with singular value decomposition (SVD), which degrades performance.
Innovation Solution
A transmitting apparatus with an ordering selector that determines the SIC scheme and a receiving apparatus with a CQI generator to optimize AMC performance by selecting the appropriate SIC ordering policy and generating MIMO equivalent channel information, using total transmission power and maximum modulation order to adaptively modulate data signals and control information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If SVD is applied to maximize MIMO channel capacity, then system capacity is maximized, but performance degrades due to errors in channel feedback
Solution Approach 1:
The patent extracts only the necessary channel information (channel quality indicator CQI) from the full MIMO channel matrix, rather than feeding back the entire channel matrix. This extraction of essential information reduces feedback errors while maintaining the ability to determine AMC levels for maximizing system capacity.
Solution Approach 2:
The patent introduces an intermediary CQI value that mediates between the transmitter and receiver. Instead of directly using the full channel matrix for AMC determination, the receiver computes CQI as an intermediary representation that captures the essential channel quality information needed for AMC level selection, reducing feedback errors.
2Reliability
If forward ordering policy is used in SIC method, then performance degradation is prevented, but AMC performance cannot be optimized because feedback channel values vary depending on channel states
Solution Approach 1:
The patent makes the ordering policy dynamic by selecting between forward and reverse ordering policies based on channel conditions. The ordering selector chooses the appropriate policy according to the current channel state, allowing the system to optimize AMC performance while maintaining reliability through adaptive policy selection.
Solution Approach 2:
The patent changes the parameter of ordering policy selection based on channel conditions. By adjusting which ordering policy is used (forward or reverse) according to channel state, the system can optimize AMC performance while preventing performance degradation through condition-dependent policy selection.
Data Source
AI summary
A transmitting and receiving apparatus and method for optimizing performance of an adaptive modulation and coding (AMC) in a multiple input and multiple output antenna (MIMO) communication system. When the AMC is applied to the MIMO system, the optimal scheme is different depending on the MIMO channel situation, the maximum transmission power, and the maximum modulation order. The transmitting apparatus includes an ordering selector that selects a successive interference cancellation (SIC) scheme in order to obtain a maximum MIMO-AMC performance, and the receiving apparatus includes a channel quality information (CQI) generator corresponding to the SIC scheme selected at the transmitting apparatus.