Massive MIMO Beam Control Feedback Reduction
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Solution Overview
Problem
Massive MIMO systems face challenges in managing inter-user and inter-cell interference, leading to increased feedback overhead due to the need for precise beam control with a large number of antennas, which affects communication quality.
Innovation Solution
The implementation of a method to control reference signals and transmission beams with reduced feedback overhead by using beam selection algorithms and bitmaps to identify optimal and suboptimal beams for user equipment, allowing for efficient beamforming and interference management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of antennas is increased to achieve Massive MIMO, then beamforming precision and spatial separation performance are improved, but feedback overhead increases due to the need for precise beam control
Solution Approach 1:
The patent segments the beam control process into two stages: first, coarse beam selection from a limited set of predefined beams; second, fine adjustment within the selected beam. This segmentation allows the system to achieve precise beamforming without requiring feedback for all possible beam configurations, thereby reducing feedback overhead while maintaining beamforming precision.
Solution Approach 2:
Instead of requiring complete feedback for all possible beam configurations (excessive action), the patent uses partial feedback by selecting a subset of candidate beams and requesting feedback only for these limited options. This partial action approach reduces the feedback burden while still enabling precise beam control through the combination of coarse selection and fine adjustment.
2Productivity
If the number of antennas is increased to form sharp beams, then frequency utilization efficiency is improved, but the width of transmission beams narrows making interference management more difficult
Solution Approach 1:
The patent implements dynamic beam adjustment where the system can switch between different beam configurations based on real-time channel conditions. The eNB can dynamically select from multiple candidate beams and adjust the beamforming parameters to optimize both frequency utilization and interference management, allowing the system to adapt to changing conditions rather than being fixed in a single narrow beam configuration.
Solution Approach 2:
The patent applies different beamforming strategies to different spatial regions and user equipment based on local channel conditions. By analyzing the specific requirements of each UE and the local interference environment, the system can optimize beam parameters locally rather than using a uniform approach, thereby maintaining narrow beams for frequency efficiency while managing interference through localized adjustments.
3Reliability
If beam selection algorithms are implemented to reduce feedback overhead, then communication quality is improved, but system complexity increases due to additional processing requirements
Solution Approach 1:
The patent performs preliminary actions by pre-configuring a limited set of candidate beams and their corresponding parameters before actual communication begins. The eNB prepares these candidate beams in advance, and the UE can then provide feedback on a subset of these pre-configured options rather than all possible beams. This preliminary action reduces the complexity of real-time decision-making while maintaining communication quality through the use of pre-planned beam configurations.
Data Source
AI summary
A radio communication system of an example includes: a first radio base station which includes an antenna including antenna elements, and configured to transmit signals from the antenna elements; and user equipment. The user equipment selects a desired signal for the user equipment by taking into account reception characteristics of the respective signals transmitted by the radio base station, and transmits a signal selection indicator to the radio base station. Based on the signal selection indicator, the radio base station determines an antenna element to transmit a signal for communications with the user equipment, and transmits a data signal precoded using a predetermined precoding vector to the user equipment.