Progressive Codebook Allocation for Wireless Interference Reduction
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Solution Overview
Problem
In cellular systems like 3G LTE and WiMAX, when multiple receivers are in close proximity, it becomes challenging to find a precoding vector that maximizes signal power for one receiver while minimizing interference to another, due to the limited granularity of the codebook, leading to either severe interference or weak signal issues.
Innovation Solution
Implementing a system where different codebooks with varying resolutions are dynamically allocated to receivers, allowing for non-overlapping beam patterns to reduce interference, with low-bit feedback used to progressively switch between low-resolution, medium-resolution, and high-resolution codebooks based on receiver feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If a single codebook with limited granularity is used for precoding, then the feedback overhead is reduced, but the ability to separate signals for closely spaced receivers deteriorates, causing either severe interference or weak signal issues
Solution Approach 1:
The codebook is segmented into multiple codebooks with different resolutions. A first codebook provides coarse beam selection, while a second codebook provides fine beam selection. This segmentation allows the system to achieve fine-grained signal separation for closely spaced receivers without requiring a single large codebook that would increase feedback overhead.
Solution Approach 2:
The solution adds a dimensional aspect to codebook selection by introducing multiple codebooks with different resolutions rather than relying on a single codebook's granularity. This multi-dimensional approach (coarse + fine resolution) enables precise beam control while maintaining efficient feedback mechanisms.
2Measurement precision
If the codebook size is increased to improve angular space granularity, then signal separation for closely spaced receivers is improved, but the feedback overhead and complexity increase
Solution Approach 1:
Instead of using one large codebook, the system segments the codebook functionality into multiple smaller codebooks with different resolutions. The first codebook handles coarse angular selection while the second codebook handles fine angular selection, achieving high measurement precision without the feedback overhead of a single large codebook.
Solution Approach 2:
The system dynamically selects which codebook(s) to use based on the specific communication scenario and receiver conditions. This dynamic adaptation allows the system to achieve high angular granularity when needed while maintaining lower complexity in other scenarios, optimizing the trade-off between precision and overhead.
Data Source
AI summary
Systems and/or methods are described for use of progressively higher-resolution codebooks for communication with one or more receivers within a cell of a base station.