MIMO Symbol Mapping Reduces Feedback Overhead
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current MIMO wireless communication systems face challenges in managing high feedback signaling due to varying channel qualities, signal strengths, and error rates in 4-branch MIMO transmissions, leading to increased complexity and overhead.
Innovation Solution
The system generates and transmits unmapped symbol blocks using different channel code characteristics, splits symbols between multiple MIMO layers, and employs precoding to optimize data transmission over a single time-frequency-resource-element (TFRE), reducing the need for extensive feedback signaling by using fixed or dynamically selected mapping functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If 4-branch MIMO transmission is used to increase data rate, then productivity is improved, but device complexity increases due to high feedback signaling requirements
Solution Approach 1:
The patent segments the 4 codewords into 2 groups, where each group is mapped to a separate MIMO layer. This segmentation allows the system to reduce feedback signaling by treating multiple codewords as a single unit for feedback purposes, thereby maintaining high data rate transmission while reducing the complexity of feedback management.
Solution Approach 2:
The patent implements a universal mapping function that can handle both 2-branch and 4-branch MIMO transmissions. This multi-functional approach allows the same feedback mechanism to serve different MIMO configurations, reducing the need for separate feedback signaling schemes for each configuration and thereby reducing overall system complexity.
2Productivity
If channel encoding for 4 codewords is performed to support 4-branch MIMO, then productivity is improved, but loss of information increases due to high feedback overhead
Solution Approach 1:
The patent merges multiple codewords into fewer MIMO layers for transmission. By combining 4 codewords into 2 layers, the system reduces the amount of feedback information needed, as feedback is now required for fewer independent transmission streams. This merging maintains data transmission capacity while reducing feedback overhead.
3Adaptability or versatility
If different MIMO layers are transmitted with different qualities and error rates, then adaptability is improved, but device complexity increases due to varying channel encoding requirements
Solution Approach 1:
The patent applies preliminary channel encoding to grouped codewords before MIMO layer mapping. By encoding codewords in advance as grouped units rather than individually per layer, the system maintains adaptability to different channel conditions while reducing the complexity of real-time encoding decisions during transmission.
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
Data may be transmitted from a RAN node to a wireless terminal using a MIMO antenna array. A plurality of unmapped symbol blocks may be generated. Symbols of a first one of the plurality of unmapped symbol blocks may be mapped to first and second mapped symbol blocks so that the first mapped symbol block includes symbols of the first unmapped symbol block and so that the second mapped symbol block includes symbols of the first unmapped symbol block. The symbols of the first and second mapped symbol blocks may be precoded to provide precoded symbols of a respective first and second MIMO precoding layers using a MIMO precoding vector. Each of the precoded symbols of the first and second MIMO precoding layers may be transmitted through the MIMO antenna array to the wireless terminal using a same TFRE. Related devices and terminals are also discussed