Single Frequency Source for Multi-Band Receiver Carrier Aggregation
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Solution Overview
Problem
LTE implementation faces challenges with fragmented frequency bands, requiring carrier aggregation across non-contiguous bands, which increases receiver complexity, cost, and power consumption due to the need for multiple RF LO synthesizers.
Innovation Solution
A method employing a single frequency source divided by different factors to generate multiple RF LO frequencies for down-converting signals, reducing spurious issues and power consumption by eliminating the need for multiple frequency sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple RF LO synthesizers are used for carrier aggregation, then the receiver can receive signals from multiple frequency bands simultaneously, but the device complexity, cost, and power consumption increase
Solution Approach 1:
The patent combines multiple RF LO synthesizers into a single frequency source that generates multiple LO frequencies through frequency division. The single frequency source is divided by different factors to produce the required LO frequencies for anchor carrier and component carriers, thereby reducing device complexity while maintaining carrier aggregation capability.
Solution Approach 2:
The single frequency source performs multiple functions by generating different LO frequencies for different carriers. Instead of having dedicated synthesizers for each carrier, the universal frequency source can be configured to provide the necessary frequencies for anchor carriers and component carriers across multiple bands, reducing overall system complexity.
2Adaptability or versatility
If multiple RF LO synthesizers are used for carrier aggregation, then the receiver can receive signals from multiple frequency bands simultaneously, but power consumption increases
Solution Approach 1:
The patent merges multiple power-consuming synthesizers into a single frequency source. By using one frequency source that is divided to generate multiple LO frequencies, the system reduces the total power consumption associated with having separate synthesizers for each carrier, while still enabling carrier aggregation across multiple frequency bands.
3Adaptability or versatility
If multiple RF LO synthesizers are used for carrier aggregation, then the receiver can receive signals from multiple frequency bands simultaneously, but spurious and injection locking issues arise
Solution Approach 1:
The patent eliminates the reliability issues associated with multiple independent synthesizers by merging them into a single frequency source. This single source, when divided to generate multiple LO frequencies, avoids the spurious signals and injection locking problems that occur when multiple synthesizers operate in close proximity, thereby improving signal reception reliability.
4Adaptability or versatility
If the RF LO frequency is changed to receive component carriers, then the receiver can tune to different frequencies, but the anchor carrier reception is interrupted
Solution Approach 1:
The patent segments the frequency generation function by using a single frequency source that is divided by different factors to generate multiple stable LO frequencies. This allows the receiver to switch between different component carrier frequencies without affecting the anchor carrier LO frequency, enabling continuous anchor carrier reception while maintaining the ability to tune to different component carriers.
Solution Approach 2:
The single frequency source provides multi-functionality by generating both the anchor carrier LO frequency and component carrier LO frequencies simultaneously. This universal frequency source can be configured to provide the necessary frequencies for multiple carriers, allowing the receiver to maintain anchor carrier reception while tuning to different component carriers as needed.
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
Enables efficient carrier aggregation with reduced complexity and power consumption, allowing continuous reception of anchor carriers and component carriers without interruption, while minimizing the complexity and cost associated with multiple synthesizers.
Implementation Method 1
The first frequency source is divided by a first factor to generate a first RF LO frequency. The first frequency source is also divided by a second factor, different from the first factor, to generate a second RF LO frequency different from the first RF LO frequency.
Implementation Method 2
The first received signal is down-converted to a first intermediate frequency signal by mixing the first received signal with the first RF LO frequency, and the second received signal is down-converted to a second intermediate frequency signal by mixing the second received signal with the second RF LO frequency.
Data Source
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AI summary
Efficient carrier aggregation is enabled in a receiver employing a single frequency source, and dividing the frequency source by different frequency dividing factors to generate two or more RF LO frequencies. Received signals are down-converted to intermediate frequencies by mixing with the respective RF LO frequencies. By utilizing only a single high frequency source, embodiments of the present invention avoid spurious and injection locking issues that arise when integrating two or more frequency sources, and additionally reduce power consumption as compared to a multiple frequency source solution.