Closed-Loop Multi-Antenna CQI Feedback for Computational Complexity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current multi-antenna systems face challenges in accurately detecting transmitted signals and efficiently allocating resources due to high error rates and increased computational complexity, particularly in mobile communications where multipath interference and fading are prevalent.
Innovation Solution
A closed-loop multi-antenna system that generates feedback information for joint detection of desired data streams and uses adaptive modulation and coding based on channel status information, employing a reception beamforming matrix and Channel Quality Information (CQI) to optimize resource allocation and reduce computational complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If full-search allocation scheme is used to achieve optimal resource allocation, then error rate performance is improved, but computational complexity and feedback information amount increase
Solution Approach 1:
The patent applies partial search allocation instead of full-search allocation. The receiver calculates CQI values for multiple hypothetical modulation schemes (e.g., 16-QAM, 64-QAM) and feeds back the best performance indicator, while the transmitter performs resource allocation based on this partial information. This reduces computational complexity compared to evaluating all possible combinations while maintaining acceptable error rate performance.
Solution Approach 2:
The patent implements a feedback mechanism where the receiver calculates Channel Quality Information (CQI) values for different modulation schemes and feeds back the best performance indicator to the transmitter. The transmitter then uses this feedback information to allocate resources optimally. This feedback loop enables adaptive resource allocation without requiring the transmitter to perform exhaustive search computations.
2Device complexity
If uniform allocation scheme is used to simplify resource allocation, then device complexity is reduced, but error rate performance deteriorates
Solution Approach 1:
The patent transitions from static uniform allocation to dynamic adaptive allocation. The system dynamically adjusts resource allocation based on real-time channel conditions by calculating CQI values for different modulation schemes and selecting the optimal allocation strategy. This dynamic approach maintains low complexity while improving error rate performance through adaptive modulation and coding.
3Device complexity
If fixed allocation scheme is used to simplify resource allocation, then device complexity is reduced, but adaptability to channel changes deteriorates
Solution Approach 1:
The patent implements dynamic resource allocation that adapts to changing channel conditions. The receiver continuously monitors channel quality and calculates CQI values for different modulation schemes, then feeds back the best performance indicator. The transmitter uses this feedback to dynamically adjust resource allocation, enabling the system to adapt to channel changes while maintaining manageable complexity through semi-automated allocation strategies.
Data Source
AI summary
An apparatus and method for transmitting/receiving data in a closed-loop multi-antenna system. A receiver receives a plurality of data streams from a plurality of transmit antennas of a transmitter, generates Channel Quality Information (CQIs) of channels that carry data streams transmitted from at least two transmit antenna allocated to the receiver among the plurality of transmit antennas, and transmits the CQIs to the transmitter. For the CQI generation, the receiver generates a channel matrix through channel estimation of the received data streams, generates a reception beamforming matrix from the channel matrix including only components of the data streams transmitted from the allocated transmit antennas, and calculates the CQIs using the channel matrix, the reception beamforming matrix, and a total signal-to-noise ratio (SNR) obtained through the channel estimation.