Massive MIMO Robust Precoding via Refined Beam Domain
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Solution Overview
Problem
Current massive MIMO systems face challenges in adapting to various mobile scenarios due to limited antenna configurations and high complexity of non-linear precoding methods, which result in suboptimal performance in scenarios with limited pilot resources and high mobility.
Innovation Solution
A robust precoding transmission method that utilizes a priori and a posteriori statistical channel information in a refined beam domain, obtained through sampling steering vectors and conjugate matrices, to perform linear precoding and reduce pilot overhead, enabling efficient adaptation to diverse scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional DFT based beam domain channel model is used, then the system can be simplified, but the model considerably deviates from actual physical channel model
Solution Approach 1:
The patent changes the parameters of the beam domain channel model by introducing a refined beam domain with multiple resolution levels. Instead of using a fixed DFT matrix, the system employs a refined sampling steering vector matrix that can adapt to different channel conditions, thereby improving accuracy while maintaining manageable complexity through parameterization of the beam domain structure.
Solution Approach 2:
The patent introduces dynamic adaptability in the channel model by enabling the beam domain to be refined based on actual channel conditions. The refined beam domain can adjust its resolution and structure dynamically, allowing the system to adapt to various mobile communication scenarios while maintaining accuracy without requiring an overly complex fixed model.
2Reliability
If non-linear precoding method is used, then optimal performance can be achieved, but the complexity is extremely high
Solution Approach 1:
The patent segments the precoding process into multiple stages by introducing a multi-stage precoding structure. Instead of using a single complex non-linear precoding operation, the system divides the precoding into several simpler stages that can be implemented sequentially, reducing the overall complexity while maintaining near-optimal performance through the combined effect of these stages.
Solution Approach 2:
The patent applies partial action by using a simplified linear precoding approach that operates on a subset of the full channel information. Rather than requiring complete and accurate channel state information for optimal performance, the system uses partial information from the refined beam domain to achieve sufficient performance, thereby reducing complexity requirements.
3Device complexity
If a simple linear regularized zero forcing precoding method is used, then the complexity is reduced, but the requirement for instantaneous channel accuracy is high
Solution Approach 1:
The patent applies preliminary action by performing channel estimation and statistical information extraction in advance before the actual data transmission. The system pre-processes the channel information to obtain statistical characteristics in the refined beam domain, which are then used to design robust precoding that can tolerate inaccuracies in the instantaneous channel information, thereby reducing the accuracy requirement while maintaining low complexity.
Solution Approach 2:
The patent incorporates feedback mechanisms where the system continuously monitors and updates the statistical channel information in the refined beam domain. This feedback allows the precoding to adapt to changing channel conditions without requiring perfectly accurate instantaneous information, as the system learns from past observations to compensate for measurement errors and uncertainties.
4Productivity
If the number of user antennas is increased, then the system capacity is improved, but the pilot resources become limited
Solution Approach 1:
The patent transitions from a traditional antenna-domain approach to a beam-domain approach, changing the dimension in which channel estimation occurs. By operating in the refined beam domain with multiple resolution levels, the system can serve more users simultaneously without requiring proportional increases in pilot resources, as the beam domain provides a more efficient basis for multiplexing and channel estimation.
Solution Approach 2:
The patent makes the pilot signals more universal by designing them to serve multiple functions simultaneously. The pilots in the refined beam domain can be used for channel estimation, statistical information extraction, and even direct precoding guidance, thereby reducing the total amount of pilot resources needed while maintaining the ability to support a large number of users.
Data Source
AI summary
The present invention discloses a massive multiple-input multiple-output (MIMO) beam domain robust precoding transmission method and system. The method is based on base station (BS)-side and user-side refined sampling steering vector matrices, and considers the influence of channel aging caused by mobility, where obtained channel state information is refined beam domain a posteriori statistical channel information including channel mean and variance information. In the present invention, the BS performs robust precoding transmission by using the refined beam domain a posteriori statistical channel information, where a channel model on which the adopted refined beam domain a posteriori statistical channel information depends is a channel model which corresponds to a refined sampling space angle and adopts a steering vector matrix; the used statistical channel information is more sufficient and accurate, so that the problem of universality of massive MIMO to various typical mobile scenarios under the condition that the antenna size is limited can be solved; and high spectral efficiency is achieved, and the provided robust precoding design utilizes the sparsity of a beam domain channel and the structural characteristics of a sampling steering vector matrix, so that the calculation complexity can be greatly reduced.