Adaptive Transmit Diversity Control for Power Reduction
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Solution Overview
Problem
Mobile transmit diversity devices face inefficiencies in power consumption, particularly at low transmitter powers, where the additional operating current of phase modulators and RF channels can decrease battery life, and at high powers, where excessive power consumption may be costly, especially when operating at the cell edge or in high fading conditions.
Innovation Solution
The solution involves a mobile communication device that dynamically switches between diversity and non-diversity modes based on transmitted power levels, using two or more antennas to adjust transmit diversity parameters such as phase and power ratios, and selectively enabling/disabling power amplifiers and phase modulators to optimize efficiency and reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transmit diversity mode is used to extend operating range, then beamforming gain and signal quality are improved, but power consumption increases due to additional operating current of phase modulators and RF channels
Solution Approach 1:
The system dynamically switches between diversity mode and non-diversity mode based on real-time power consumption measurements and signal quality requirements. The controller monitors power usage and adapts the transmission mode accordingly, making the system flexible and adaptive to changing conditions.
Solution Approach 2:
The invention changes the operational parameters of the transmission system by adjusting the transmit diversity parameter (e.g., phase difference between antennas) to optimize the balance between signal quality and power consumption. This allows the system to achieve beamforming gain when needed while reducing power usage when full diversity is not required.
2Length of moving object
If both power amplifiers operate at full power to maximize transmission range, then operating range is extended, but excessive power consumption occurs especially at cell edge or in high fading conditions
Solution Approach 1:
The system uses partial action by operating one or both power amplifiers at less than full power when sufficient. The controller determines when full power is actually needed versus when reduced power levels are adequate, avoiding excessive energy consumption while maintaining sufficient operating range.
Solution Approach 2:
The system incorporates feedback mechanisms where the controller monitors transmission conditions and power consumption, then adjusts the power amplifier output accordingly. This feedback loop ensures that power is only consumed at high levels when actually necessary for maintaining connection at cell edge or in high fading conditions.
3Productivity
If transmit diversity is enabled to achieve beamforming gain, then data rate and network capacity are improved, but additional operating current decreases battery life
Solution Approach 1:
The system dynamically adjusts the transmission mode based on real-time conditions, switching between diversity mode for high data rate requirements and non-diversity mode for power saving. This dynamic adaptation allows the system to maximize battery life while maintaining productivity when needed.
Solution Approach 2:
The system periodically evaluates power consumption and signal quality conditions to determine when to switch between transmission modes. This periodic assessment ensures that diversity mode is only active when it provides net benefit to both data rate and power efficiency.
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 allows for power savings when beneficial and maintains efficient operation by adjusting transmit diversity modes according to power requirements, reducing excessive power consumption and extending battery life while maintaining high data rates and network capacity.
Implementation Method 1
two power amplifiers may be used to amplify the respective transmit signals
Implementation Method 2
a phase modulator (PM) and an antenna. When configured to provide beam forming MTD, the relative phase between the two paths may be adjusted
Implementation Method 3
an antenna. When configured to provide beam forming MTD, the relative phase between the two paths may be adjusted such that the signals arrive at the base station antenna
Implementation Method 4
obtain constructive interference, also known as beamforming, of the transmit signals at the receiver
Data Source
AI summary
A method and apparatus for selectively enabling or disabling transmit diversity in a mobile communication device. The mobile communication device may switch between diversity and non-diversity operation based on various transmit power considerations.