Antenna Device Secondary Precoder Power Balancing MIMO
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Solution Overview
Problem
Existing radio communications systems face inefficiencies in power amplification due to uneven power sharing between antennas in Multiple-Input Multiple-Output (MIMO) systems, particularly when supporting both MIMO-enabled and legacy User Equipment (UE), leading to suboptimal resource utilization and potential interference issues.
Innovation Solution
The implementation of a secondary precoder, operating with a specific precoder matrix, is used to distribute power equally between power amplifiers by transforming signals to orthogonal polarizations, ensuring balanced power amplification for both MIMO and Single-Input Single-Output (SISO) signals, and optimizing polarization states for improved transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If all system vital information and traffic channels are transmitted on a single antenna to support legacy UEs, then compatibility with legacy UEs is maintained, but power amplifier utilization becomes suboptimal with uneven power sharing
Solution Approach 1:
The transmission is segmented into two independent paths: a single-antenna path for legacy UE compatibility and a multi-antenna MIMO path for modern UEs. The base station dynamically selects which path to use based on UE capability, ensuring that legacy UEs receive signals from one antenna while MIMO-capable UEs utilize multiple antennas for spatial multiplexing, thereby optimizing power amplifier utilization across different UE categories.
Solution Approach 2:
The system dynamically adapts its transmission mode based on UE capability detection. When a legacy UE is detected, the system switches to single-antenna transmission for that UE. When MIMO-capable UEs are present, the system activates multi-antenna MIMO transmission. This dynamic switching ensures optimal power amplifier utilization while maintaining backward compatibility.
2Use of energy by moving object
If Butler matrices are used to distribute load equally over PAs, then power sharing between antennas is balanced, but hardware complexity increases and power loss is introduced
Solution Approach 1:
The invention extracts and removes the Butler matrix component from the system architecture. Instead of using complex hardware-based power distribution networks, the patent achieves power balancing through digital signal processing and intelligent antenna selection algorithms. This extraction eliminates the need for additional hardware while maintaining power sharing balance across amplifiers.
Solution Approach 2:
The patent replaces the mechanical/electrical Butler matrix structure with a software-based solution involving digital precoding and antenna selection algorithms. The power distribution function previously performed by physical hardware is now achieved through computational methods, reducing hardware complexity while maintaining the desired power balancing effect.
3Use of energy by moving object
If STTD encoding is used to alleviate PA power balancing, then power sharing is improved, but performance on scheduled channels like HS-DSCH deteriorates due to increased interference
Solution Approach 1:
The system performs preliminary UE capability assessment and channel condition evaluation before transmission. Based on this preliminary information, it pre-determines the optimal transmission mode (single-antenna or MIMO) and selects appropriate antennas and power distribution strategies. This preliminary action prevents the need for STTD encoding in scenarios where it would harm performance, as the system proactively configures the transmission to avoid interference issues on scheduled channels.
Solution Approach 2:
The patent dynamically changes transmission parameters including antenna selection, power allocation, and modulation schemes based on channel conditions and UE capabilities. Instead of applying fixed STTD encoding, the system adapts parameters in real-time to optimize both power sharing and channel performance, switching between different transmission modes as needed to maintain high reliability on scheduled channels.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach achieves full power balancing at power amplifiers, reducing interference and enhancing data throughput by ensuring equal power utilization across antennas, regardless of signal correlation, and maintaining optimal performance for various UE categories.
Implementation Method 1
The implementation of a secondary precoder, operating with a specific precoder matrix, is used to distribute power equally between power amplifiers by transforming signals to orthogonal polarizations
Data Source
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AI summary
The invention relates to the technical field of radio communications, and in particular to an antenna device for a radio base station, and a method for precoding data in a Multiple-Input Multiple-Output (MIMO) system. Embodiments of the invention disclose a secondary precoder 24 in series with a multiple-input multiple-output precoder 22. The secondary precoder 24 has a plurality of inputs 34, 36 and a plurality of outputs 38, 40. The second plurality of inputs being in communication with each plurality of outputs 38, 40 such that one or more signals input to a respective one or more of the second plurality of inputs 34, 36 provides a substantially equal power of signals at the second plurality of outputs 38, 40.