Downlink Precoding Feedback Using Valid Orthogonal Bases
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Solution Overview
Problem
In wireless communications systems with partial channel reciprocity, existing methods fail to optimize downlink precoding effectively due to insufficient utilization of uplink channel information, leading to inefficiencies in channel capacity and performance.
Innovation Solution
A method and apparatus that enable a terminal to send information for determining the position and coefficient of valid orthogonal bases to a network side, allowing the network side to optimize downlink precoding based on this information, thereby reducing feedback overheads and improving channel capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal sends complete channel state information including spatial domain orthogonal basis, bitmap, and delay position, then the downlink precoding optimization is improved, but the feedback overhead increases
Solution Approach 1:
The patent extracts only the essential information needed for downlink precoding optimization: the position of valid orthogonal bases and their coefficients. By removing redundant information (complete spatial domain orthogonal basis, bitmap, delay position), the feedback overhead is reduced while maintaining the core functionality of precoding optimization through partial channel reciprocity utilization.
Solution Approach 2:
The patent applies partial action by sending only the necessary portion of channel state information (position and coefficient of valid orthogonal bases) rather than complete CSI. This partial information is sufficient for the network side to perform effective downlink precoding optimization, achieving a balance between optimization quality and feedback efficiency.
2Productivity
If the terminal sends spatial domain orthogonal basis and delay position, then the channel capacity is improved, but the signaling complexity increases
Solution Approach 1:
The patent extracts only the critical elements (position and coefficient of valid orthogonal bases) from the complete channel state information. This extraction reduces signaling complexity by eliminating the need to transmit full spatial domain orthogonal basis and delay position, while still enabling channel capacity improvement through effective precoding.
3Device complexity
If the network side uses only angular domain reciprocity for precoding design, then the system complexity is reduced, but the precoding performance is insufficient
Solution Approach 1:
The patent extends the precoding design from single angular domain reciprocity to incorporate delay domain information through valid orthogonal bases. By adding this temporal dimension (delay position and coefficients), the system achieves better precoding performance while maintaining manageable complexity through selective information transmission.
Data Source
AI summary
A transmission method and apparatus, a device, and a readable storage medium are disclosed. The method includes: sending, by a terminal, information for determining a position of a valid orthogonal basis and a coefficient of the valid orthogonal basis to a network side; wherein the information for determining the position of the valid orthogonal basis comprises at most two of spatial domain orthogonal basis, bitmap, or delay position. The method further comprises: receiving, by the terminal, first indication information that indicates the terminal not to send the spatial domain orthogonal basis and the delay position; sending the information for determining the position of the valid orthogonal basis to the network side comprises: sending the information for determining the position of the valid orthogonal basis to the network side, wherein the information does not comprise the bitmap, the delay position, and the spatial domain orthogonal basis.