Dynamic Local Oscillator Scheme for Carrier Aggregation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in minimizing current consumption while maintaining receiver de-sense performance and avoiding voltage-controlled oscillator (VCO) and local oscillator (LO) coupling in carrier aggregation scenarios.
Innovation Solution
A dynamic local oscillator (LO) scheme and reconfigurable receive paths are implemented, allowing for retuning of frequency synthesizers, changing divide ratios, and switching between LO paths to optimize current consumption and minimize coupling, by using a combination of low noise amplifiers (LNAs) and mixers with different LO signals generated by frequency synthesizers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single LO path is used for carrier aggregation, then device complexity is reduced, but VCO and LO coupling increases causing receiver de-sense
Solution Approach 1:
The patent divides the LO generation into multiple independent paths (first LO path with first frequency synthesizer and second LO path with second frequency synthesizer), each serving specific receive paths. This segmentation allows independent control of each LO path to avoid coupling between component carriers while maintaining manageable device complexity through modular architecture.
Solution Approach 2:
The patent introduces a controller as an intermediary that dynamically manages LO path selection and switching based on which component carriers are actively received. This intermediary coordinates between the multiple frequency synthesizers and receive paths, enabling optimal LO path assignment to prevent VCO and LO coupling while minimizing overall system complexity.
2Object-affected harmful factors
If multiple frequency synthesizers are used for different component carriers, then LO coupling is avoided, but current consumption increases
Solution Approach 1:
The patent implements dynamic LO path management where the controller selectively activates or deactivates specific frequency synthesizers and LO paths based on which component carriers are currently being received. This dynamic approach ensures that multiple frequency synthesizers are not simultaneously active unless necessary, thereby avoiding VCO and LO coupling while minimizing current consumption by powering down unused synthesizers.
Solution Approach 2:
The patent changes the operational parameters of the frequency synthesizers by adjusting their output frequencies and activation states based on the specific component carrier configuration. By retuning synthesizers to appropriate frequencies and activating only the necessary LO paths for currently active component carriers, the system avoids coupling issues while optimizing current consumption according to the actual reception requirements.
3Use of energy by moving object
If LO paths are dynamically reconfigured when adding or discontinuing component carriers, then current consumption is minimized, but device complexity increases
Solution Approach 1:
The patent designs the LO generation system with universal components that can serve multiple functions. The first and second frequency synthesizers can both generate LO signals for different receive paths, and the controller universally manages all LO path configurations. This multi-functionality allows the same hardware components to be dynamically reassigned based on component carrier addition or discontinuation, minimizing current consumption without requiring entirely separate dedicated paths for each scenario.
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 minimal current consumption while maintaining receiver de-sense performance and reducing VCO and LO coupling, especially when adding or discontinuing component carriers in carrier aggregation, leading to efficient power management and improved system stability.
Implementation Method 1
a first low noise amplifier (LNA) configured to amplify the first CC
Implementation Method 2
a first mixer configured to multiply the amplified first CC with a first LO signal
Implementation Method 3
generated by a first frequency synthesizer whose output frequency is divided down by a first divide ratio to create the first LO signal
Implementation Method 4
generated by a second frequency synthesizer whose output frequency is divided down by a second divide ratio to create the first LO signal
Data Source
AI summary
Certain aspects of the present disclosure provide methods and apparatus for dynamically adjusting a voltage-controlled oscillator (VCO) frequency, a local oscillator (LO) divider ratio, and/or a receive path when adding or discontinuing reception of a component carrier (CC) in a carrier aggregation (CA) scheme. This dynamic adjustment is utilized to avoid (or at least reduce) VCO, LO, and transmit signal coupling issues with multiple component carriers, with minimal (or at least reduced) current consumption by the VCO and the LO divider.