eNodeB Channel Training Signal Subspace Reduction
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Solution Overview
Problem
In FD-MIMO systems, the overhead associated with transmitting channel training signals increases linearly with the number of antenna elements, leading to prohibitive resource usage and potential throughput reduction due to latency and interference, especially with large antenna arrays.
Innovation Solution
The solution involves selectively transmitting channel training signals to specific signal subspaces identified by beamforming vectors that produce high signal energy, while skipping the null subspace to reduce transmission overhead, with the eNB dynamically updating these subspaces based on feedback to maintain efficient communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If channel training signals are transmitted for all antenna elements in FD-MIMO systems, then channel estimation accuracy is improved, but resource overhead increases linearly with the number of antenna elements
Solution Approach 1:
The patent segments the antenna elements into multiple antenna ports, where each antenna port represents a group of antenna elements. Instead of transmitting separate channel training signals for each individual antenna element, the system transmits channel training signals for each antenna port, thereby reducing the number of training signals required while maintaining channel estimation capability.
Solution Approach 2:
The patent extracts only the essential information needed for channel estimation by using antenna ports rather than individual antenna elements. This extraction approach removes redundant training signals while preserving the core functionality of channel estimation, directly reducing resource overhead.
2Measurement precision
If channel training signals are transmitted for all antenna elements, then channel feedback quality is improved, but transmission latency increases
Solution Approach 1:
By segmenting antenna elements into antenna ports, the system reduces the total number of training signals that need to be transmitted sequentially. This segmentation allows channel feedback to be obtained more quickly, reducing transmission latency while maintaining feedback quality through the use of antenna port-level channel information.
3Manufacturing precision
If channel training signals are transmitted for all antenna elements, then beamforming accuracy is improved, but interference increases
Solution Approach 1:
The patent extracts the essential beamforming information at the antenna port level rather than requiring individual antenna element-level training. This extraction reduces the number of active training transmissions, thereby reducing interference while preserving beamforming accuracy through the use of antenna port channel state information.
Data Source
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AI summary
In embodiments, apparatuses, methods, and storage media may be described for reducing the overhead associated with the transmission of channel training signals from an eNodeB (eNB) of a wireless network. Specifically, the eNB may receive feedback from a user equipment (UE) regarding the received signal energy of a first and second beamformed signal produced with a first and second beamforming vector, respectively. The eNB may identify, based on the feedback of the received signal energy, a signal subspace and a null subspace. The eNB may then transmit a channel training signal to the signal subspace.