MU-MIMO Precoding Vector Selection for Interference Reduction
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Solution Overview
Problem
In multi-user MIMO communication systems, data transmission performance is deteriorated due to interference between terminals using the same precoding vector, leading to inefficient resource utilization and reduced data rates.
Innovation Solution
A multi-user MIMO communication scheme where terminals select consecutive precoding vectors from a precoding matrix and feed back information associated with these vectors to the base station, allowing the base station to identify and transmit data using non-overlapping vectors, thereby enhancing data transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the base station transmits data to multiple terminals using the same precoding vector, then resource utilization is improved, but data transmission performance deteriorates due to interference between terminals
Solution Approach 1:
The invention segments the precoding vectors into different groups or sets, where each terminal is assigned a distinct precoding vector from the codebook. By dividing the available precoding vectors into multiple non-overlapping sets, the system enables simultaneous transmission to multiple terminals without interference, thus resolving the contradiction between resource utilization and transmission performance
Solution Approach 2:
The invention introduces a new dimension of differentiation by using multiple codebooks or codebook groups, each containing distinct precoding vectors. This dimensional expansion allows the system to assign orthogonal or non-interfering precoding vectors to different terminals, enabling multi-user transmission while maintaining high data rates for each user
2Reliability
If the base station selects only a single terminal from multiple terminals having the same precoding vector, then interference is avoided, but resource utilization decreases
Solution Approach 1:
The invention makes precoding vectors universal by organizing them into codebook groups that can be shared across multiple terminals. Each terminal can select from its assigned codebook group, allowing the same precoding vector to be used by multiple terminals in different codebook groups simultaneously, thus enabling resource reuse without interference
Solution Approach 2:
The system dynamically assigns terminals to different codebook groups based on channel conditions, terminal locations, and traffic requirements. This dynamic allocation allows the base station to optimize resource utilization in real-time while ensuring that terminals using the same precoding vector are spatially or channel-wise separated, preventing interference
3Reliability
If each terminal selects a different precoding vector to enhance data transmission performance, then interference is reduced, but feedback information complexity increases
Solution Approach 1:
The codebook is segmented into multiple codebook groups, each containing a subset of precoding vectors. Terminals only need to feedback information about their selected precoding vector within their assigned codebook group, rather than searching the entire codebook. This segmentation reduces the feedback information complexity while still enabling distinct precoding vector selection for multiple terminals
Solution Approach 2:
Instead of requiring terminals to feedback complete precoding matrix information or exhaustive channel state information, the system uses partial feedback where terminals only report the index or identifier of their selected precoding vector within the codebook group. This partial action approach reduces feedback overhead while maintaining the ability to differentiate between multiple users
Data Source
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AI summary
Provided is a multi-user Multiple Input Multiple Output (MU-MIMO) communication scheme. A terminal may select a precoding vector from column vectors included in a precoding matrix, and feed back information associated with the selected precoding vector to a base station. The base station may transmit data to the terminal using the precoding vector.