MU-MIMO Base Station Feedback Projection Matrix
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Solution Overview
Problem
In MU-MIMO-based multi-cell cooperative communication systems, the existing methods face challenges in efficiently transmitting feedback information from base stations to network entities, leading to high backhaul overhead due to the large size of channel information and uplink data, which is proportional to the number of antennas and users.
Innovation Solution
The method involves obtaining a projection matrix based on channel information between base station antennas and user equipment antennas, projecting channel information and uplink data from a first space to a second space, and transmitting only the projected feedback information to reduce the size of data transmitted to the network entity, thereby minimizing backhaul overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If channel information and uplink data are transmitted directly from base station to network entity, then complete information is provided for processing, but backhaul overhead becomes excessively large due to proportionality with number of antennas and users
Solution Approach 1:
The patent extracts only the essential information needed for network entity processing by projecting channel information and uplink data onto a reduced-dimensional space. Instead of transmitting complete high-dimensional channel matrices and raw uplink data, the base station processes these inputs locally and transmits only the projected results, thereby removing redundant information while preserving processing capability.
Solution Approach 2:
The patent transforms the data from high-dimensional space (proportional to number of antennas and users) to low-dimensional space through projection operations. This dimensionality reduction converts the original large-scale channel matrices and data vectors into compressed representations that maintain essential characteristics while occupying significantly less transmission bandwidth.
2Quantity of substance
If projection processing is applied to channel information and uplink data, then backhaul overhead is reduced, but processing complexity at base station increases
Solution Approach 1:
The patent performs projection processing as a preliminary action at the base station before transmission. By pre-processing channel information and uplink data through projection operations, the base station prepares compressed representations in advance, shifting the processing burden from the network entity to the base station and enabling more efficient subsequent transmission and processing at centralised locations.
3Productivity
If feedback information size is reduced through projection, then transmission efficiency improves, but potential loss of processing accuracy may occur
Solution Approach 1:
The patent changes the parameter representation of channel information and uplink data by transforming them into projected space. This parameter transformation maintains the essential characteristics needed for accurate processing while reducing the overall data size. The projection operations preserve critical signal properties and channel characteristics, ensuring that processing accuracy is maintained despite the reduction in information dimensionality.
Data Source
AI summary
According to one embodiment of the present invention, a method of transmitting feedback information by a base station supporting multi-user multi-input multi-output (MU-MIMO) to a network entity includes obtaining a projection matrix based on channel information estimated for multiple channels between antennas of the base station and each of user equipments, projecting at least one of the channel information and uplink data received from the user equipments to a second space from a first space using the projection matrix and transmitting feedback information including at least one of the projected channel information and the projected uplink data to the network entity.