Reconfigurable Receiver Mixer Frequency Adaptation
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Solution Overview
Problem
Existing multi-carrier reception technologies face challenges in efficiently managing interference due to IQ imbalance and harmonic mixing, which affect the Signal-to-Interference plus Noise-Ratio (SINR) and require additional signaling overhead for carrier selection in cognitive radio systems.
Innovation Solution
A reconfigurable receiver structure that adjusts RF and IF mixer frequencies based on estimated noise and interference conditions, allowing for adaptive configuration without changing RF carrier frequencies, thereby improving reception by selecting optimal receiver configurations to match current interference characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a double conversion receiver is used to enable cost-efficient and hardware-efficient implementation with shared RF front-end, then hardware cost and power consumption are reduced, but the receiver becomes more susceptible to IQ imbalance and harmonic mixing interference
Solution Approach 1:
The patent implements dynamic selection between different receiver configurations (direct conversion and double conversion) based on real-time interference conditions. The system adapts its architecture by switching configurations to optimize performance, making the receiver structure dynamic rather than static, thereby resolving the contradiction between hardware efficiency and interference susceptibility.
Solution Approach 2:
The patent changes the operational parameters of the receiver by adjusting the RF mixer frequency dynamically. By varying the mixer frequency based on measured interference conditions, the system can avoid frequencies that cause severe IQ imbalance or harmonic mixing, thus maintaining hardware efficiency while reducing interference susceptibility.
2Reliability
If cognitive radio is used to select carriers with higher SINR, then reception quality is improved, but additional signaling overhead is required for SINR information and channel selection
Solution Approach 1:
The patent implements self-service by having the receiver autonomously measure interference conditions and autonomously select optimal receiver configurations without needing to request or receive carrier selection instructions from the transmitter. This eliminates the signaling overhead for carrier selection while maintaining high reception quality through self-adaptation.
Solution Approach 2:
The patent uses feedback by continuously measuring interference conditions at the receiver and using this feedback to dynamically adjust the receiver configuration. This closed-loop feedback mechanism enables the system to maintain high SINR without requiring additional open-loop signaling for carrier selection, as the adaptation happens automatically at the receiver side.
3Reliability
If RF mixer frequency is changed to avoid image signal interference, then SINR is improved, but the receiver configuration becomes more complex
Solution Approach 1:
The patent applies universality by designing a single reconfigurable receiver that can operate in multiple configurations (direct conversion and double conversion) and adapt to different interference conditions. This multi-functional design avoids the need for multiple dedicated receivers for different scenarios, thereby improving SINR without proportionally increasing overall system complexity.
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 enhances reception quality by dynamically adapting to changing interference conditions, reducing interference levels and maintaining performance without the need for additional signaling overhead or carrier frequency changes.
Implementation Method 1
a first radio frequency (RF) carrier and a second RF carrier may be received over respective first and second RF carrier frequencies. During a first time period, the first and second RF carriers may be downconverted through an RF mixer stage using a first RF mixer frequency to generate first downconverted signals
Data Source
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AI summary
Methods may be provided to simultaneously receive first and second RF (radio frequency) carriers over respective first and second RF carrier frequencies. More particularly, the first and second RF carriers may be provided at an RF mixer stage (401). During a first time period, the first and second RF carriers may be down converted through the RF mixer stage using a first RF mixer frequency to generate first downconverted signals (415), and the first downconverted signals may be processed to provide first and second DC carriers corresponding to the first and second RF carriers (417). During a second time period, the first and second RF carriers may be downconverted through the RF mixer stage using a second RF mixer frequency to generate second downconverted signals with the first and second RF mixer frequencies being different (409), and the second downconverted signals may be processed to provide the first and second DC carriers corresponding to the first and second RF carriers (411). Related devices are also discussed.