Adaptive Precoding Matrix Selection for Wireless Signal Coverage
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Solution Overview
Problem
In multi-antenna wireless communications systems, errors in direction of arrival estimation and antenna spacing lead to mismatches in precoding matrices, resulting in low signal quality and system performance due to narrow 3-dB beam coverage.
Innovation Solution
A method involving a transmit side that sends precoded pilot signals using both a current precoding matrix and multiple correction matrices, allowing the receive side to provide feedback for adaptive adjustment of the precoding matrix to match the actual transmission channel, ensuring improved signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a precoding matrix is computed according to DOA estimation by a base station, then the precoding matrix can be generated for data transmission, but the beam coverage becomes too narrow to cover the terminal due to estimation errors and antenna spacing issues
Solution Approach 1:
The base station dynamically adjusts the precoding matrix based on feedback from multiple candidate matrices. Instead of using a static precoding matrix based on initial DOA estimation, the system continuously adapts by selecting from multiple dynamically generated candidate matrices, allowing the beam coverage to expand and track the terminal's movement.
Solution Approach 2:
The system changes the parameters of the precoding matrix by generating multiple candidate matrices with different correction values. These candidate matrices have varying beam directions and widths, allowing the system to select the most appropriate one to cover the terminal, thereby resolving the contradiction between estimation accuracy and coverage area.
2Length of stationary object
If the spacing between multiple antennas does not satisfy DOA estimation requirement or coupling happens between antennas, then the base station can be configured with practical antenna spacing, but the DOA estimation error increases significantly
Solution Approach 1:
The system compensates for potential DOA estimation errors by generating multiple candidate precoding matrices with correction values before actual data transmission. This beforehand cushioning approach ensures that even if the initial DOA estimation is inaccurate due to antenna spacing or coupling issues, the system still has alternative precoding matrices to select from, maintaining transmission quality.
Solution Approach 2:
The terminal provides feedback information about signal quality for multiple candidate precoding matrices. Based on this feedback, the base station selects the most appropriate precoding matrix, creating a closed-loop system that compensates for initial estimation errors caused by practical antenna spacing constraints.
3Power
If a relatively large quantity of antennas are configured for the base station, then the system can achieve higher gain, but the 3-dB beam width becomes very narrow making it difficult to cover the terminal
Solution Approach 1:
The system dynamically selects from multiple candidate precoding matrices generated with different correction values. This dynamic selection allows the system to adjust the beam width and direction in real-time, maintaining high transmission gain while ensuring adequate coverage area by adapting to the terminal's position.
Solution Approach 2:
By generating candidate precoding matrices with different correction parameters, the system can change the beam characteristics (width and direction) while maintaining high gain. This parameter variation allows the system to resolve the contradiction between achieving high transmission gain with many antennas and maintaining sufficient beam coverage area.
Data Source
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AI summary
Embodiments of the present invention disclose a precoding information collection method and a transmission device and relate to the communications field, so as to improve performance of a wireless communications system. A specific solution is: precoding, by a transmit side, a first pilot signal according to a first precoding matrix, and sending a precoded first pilot signal to a receive side, where the first precoding matrix is the same as a precoding matrix used for current data transmission; precoding, by the transmit side, N second pilot signals according to N second precoding matrices, and sending N precoded second pilot signals to the receive side, where N is an integer greater than or equal to 1, the second precoding matrices used for precoding the second pilot signals are different from each other, and the N second precoding matrices are different from the first precoding matrix; and receiving, by the transmit side, precoding feedback information sent by the receive side. The present invention is used in a data transmission process.