Uplink Precoding Matrix Indication for Low-Overhead Sub-Band Precoding
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Solution Overview
Problem
Existing wireless communication systems, such as LTE and NR, only support wideband precoding for uplink signals, limiting the ability to indicate sub-band precoding, which is necessary for frequency selective gains.
Innovation Solution
A method and apparatus for determining and indicating a set of sub-band precoding matrices within the uplink codebook, allowing for sub-band precoding matrix indication through a subset of matrices, reducing overhead by indicating fewer matrices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If wideband precoding is used for uplink signal transmission, then the system is simple to implement and maintain compatibility with existing LTE and NR systems, but the ability to indicate sub-band precoding is lost, limiting frequency selective gains
Solution Approach 1:
The patent segments the wideband precoding indication into sub-band precoding indications. The frequency band is divided into multiple sub-bands, and separate precoding matrices are indicated for each sub-band. This allows frequency selective precoding while maintaining a structured approach similar to the existing wideband indication mechanism.
Solution Approach 2:
The patent introduces a new dimension to the precoding indication by adding sub-band granularity. Instead of a single wideband precoding matrix, the system now indicates precoding matrices across multiple frequency dimensions (sub-bands), enabling frequency selective optimization without abandoning the existing indication framework.
2Reliability
If sub-band precoding matrices are indicated for each sub-band, then frequency selective precoding performance is improved, but the overhead of precoding matrix indication increases
Solution Approach 1:
The patent applies local quality by selecting different precoding matrices for different sub-bands based on their specific channel characteristics. Each sub-band can use an optimized precoding matrix tailored to its local frequency conditions, improving transmission performance while the overall system maintains efficiency through selective indication.
Solution Approach 2:
The patent uses partial action by indicating precoding matrices for only the necessary sub-bands rather than all possible sub-bands. The system selectively applies sub-band precoding indication where it provides the most benefit, reducing overhead while maintaining performance improvements in critical frequency regions.
Data Source
AI summary
A precoding matrix indication method, a precoding matrix determination method, apparatuses and a medium are provided. The precoding matrix indication method includes: determining, by a network side, a set of sub-band precoding matrices, the set of sub-band precoding matrices being a sub-set in an uplink codebook of an uplink signal; determining sub-band information of precoding matrix indication information of the uplink signal in accordance with the set of sub-band precoding matrices, the sub-band information being used to indicate a sub-band precoding matrix that corresponds to each sub-band and is in the set of sub-band precoding matrices; transmitting the precoding matrix indication information including the sub-band information to a UE. The UE determines the sub-band precoding matrix corresponding to each sub-band in the set of sub-band precoding matrices in accordance with the sub-band information.