Low-Power FSK Demodulation Circuit Using Frequency Mixing
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Solution Overview
Problem
The high power consumption of signal receiving circuits in electronic devices due to processing signals of two frequencies representing digital signals 1 and 0, such as in FSK and GFSK modulation, necessitates a more efficient demodulation method to reduce power consumption and improve battery life.
Innovation Solution
A signal processing method and circuit that filters out high-frequency signals from mixed signals representing digital signals 1 and 0, using frequency mixing and low-pass filtering to reduce the frequency and power consumption of the signal processing circuit, and selectively powers up Bluetooth communication units only when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the signal processing circuit processes both high-frequency and low-frequency signals to demodulate FSK/GFSK modulation, then the digital signal can be accurately obtained, but the power consumption increases significantly
Solution Approach 1:
The patent extracts and removes the high-frequency signal component from the mixed signal through frequency mixing and low-pass filtering. By taking out the high-frequency component (third frequency signal) and retaining only the low-frequency component (fourth frequency signal), the system achieves accurate demodulation while significantly reducing power consumption, as the low-pass filter processes signals at a lower frequency requiring less energy.
Solution Approach 2:
The patent changes the frequency parameter of the signal through frequency mixing operations. The mixed signal containing high-frequency components is transformed into a signal with lower frequency components through the low-pass filter, which changes the operating frequency parameter and thereby reduces power consumption while maintaining demodulation accuracy.
2Reliability
If the Bluetooth communication unit is kept powered on to ensure immediate communication availability, then communication reliability is improved, but power consumption increases
Solution Approach 1:
The patent implements preliminary action by using the low-pass filtered signal to detect wake-up conditions before activating the Bluetooth communication unit. The signal processing circuit preliminarily processes the incoming signal to identify whether it contains relevant information, and only then activates the Bluetooth unit, avoiding unnecessary power consumption while ensuring communication reliability when needed.
Solution Approach 2:
The patent applies dynamics by making the Bluetooth communication unit's power state adjustable rather than fixed. The system dynamically transitions the Bluetooth unit between powered-on and powered-off states based on the processed signal content, allowing the system to adapt power consumption to actual communication needs while maintaining reliability.
3Productivity
If the signal processing circuit continuously processes incoming radio frequency signals, then no signal is missed, but power consumption increases
Solution Approach 1:
The patent maintains continuity of useful action by keeping the signal processing circuit active for continuous low-pass filtering and wake-up condition detection, while allowing the Bluetooth communication unit to be powered off when not needed. This ensures continuous signal monitoring and processing capability without the high power consumption of continuously active Bluetooth operations.
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 reduces power consumption by minimizing the processing of high-frequency signals and unnecessary Bluetooth unit activation, thereby enhancing battery life and user experience through efficient signal processing.
Implementation Method 1
The signal processing circuit performs frequency mixing on the radio frequency signal to obtain a mixed signal
Implementation Method 2
The signal processing circuit filters out the third frequency signal in the mixed signal to obtain a filtered signal
Data Source
AI summary
After receiving a radio frequency signal that uses two frequencies to represent a digital signal 1 and a digital signal 0 respectively, a signal processing circuit filters out a high-frequency signal from the radio frequency signal and compares an envelope detection signal corresponding to a low-frequency signal with a reference signal to determine a digital signal corresponding to the radio frequency signal.