Unequal Bit Allocation for Channel State Information Feedback
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Solution Overview
Problem
The increasing number of antennas and channel paths in wireless communication devices leads to a surge in required feedback, resulting in additional overhead that reduces the efficiency of wireless communication, such as decreased data rates.
Innovation Solution
Implementing CSI reporting schemes based on unequal bit allocation in advanced wireless communication systems to efficiently manage channel state information feedback, thereby reducing signaling overhead and enhancing data rate efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of antennas and channel paths is increased to improve wireless communication capacity, then the data transmission capability is improved, but the feedback overhead increases and data rate efficiency decreases
Solution Approach 1:
The feedback information is segmented into two parts: wideband CSI feedback and subband CSI feedback. The wideband feedback provides coarse-grained channel state information across the entire bandwidth, while subband feedback provides fine-grained information only for specific frequency subbands. This segmentation allows the system to capture essential channel characteristics without transmitting excessive feedback data, thus resolving the contradiction between communication capacity and feedback overhead.
Solution Approach 2:
The patent applies local quality by allocating different feedback precision to different frequency subbands. Instead of providing uniform high-resolution feedback across all frequencies, the system provides detailed subband feedback only where needed (in regions with significant channel variations) and uses coarser wideband feedback in other regions. This selective approach reduces overall feedback overhead while maintaining communication capacity where it matters most.
2Measurement precision
If detailed channel state information feedback is provided to improve channel estimation accuracy, then the communication efficiency is improved, but the signaling overhead increases
Solution Approach 1:
Channel state information feedback is divided into wideband CSI and subband CSI components. The wideband feedback captures overall channel characteristics with lower precision, while subband feedback provides higher precision measurements only for specific frequency subbands. This segmentation enables accurate channel estimation in critical frequency regions while reducing the total volume of feedback signaling required.
Solution Approach 2:
The system applies partial action by providing detailed subband feedback only for certain frequency subbands rather than for all subbands. This selective feedback approach ensures accurate channel estimation where channel variations are significant or where data transmission is scheduled, while reducing signaling overhead in regions where full precision is not required.
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AI summary
The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (loT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the loT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. Methods and apparatuses for reporting channel state information (CSI) is disclosed. A method performed by a terminal in a communication system, the method comprising: receiving, from a base station via a higher layer signaling, information configuring the terminal to report a wideband amplitude with or without a subband amplitude; generating a channel state information, CSI, report for a precoding matrix indicator, PMI, including wideband amplitude coefficients with or without subband amplitude coefficients according to the information; transmitting the CSI report to the base station, wherein a number of bits for the strongest wideband amplitude coefficient N1,I,0 out of 2L coefficients, and the strongest subband amplitude coefficient N2,I,0 out of 2L coefficients is 0, wherein a number of bits for the wideband amplitude coefficient N1,I,i is 3 for each of remaining 2L-1 coefficients, wherein, in case that the information configures the terminal to report the wideband amplitude coefficient with the subband amplitude coefficient, a number of bits for the subband amplitude coefficient N2,I,i is 1 for each of K-1 strongest coefficients out of remaining 2L-1 coefficients and 0 for each of 2L-K remaining coefficient, wherein, in case that the information configures the terminal to report the wideband amplitude coefficient without the subband amplitude coefficient, a number of bits for the subband amplitude coefficient N2,I,i is 0 for each of remaining 2L-1 coefficients, and wherein L is a number of beams