PLL Clock Multiplication to Avoid PMU Harmonic Channel Interference
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Solution Overview
Problem
Cellular phones experience communication interference due to noise coupling from the power management unit's harmonics, which exceed GSM noise boundaries, preventing communication on cellular networks.
Innovation Solution
Implementing a phase lock loop (PLL) to multiply the PMU clocking signal by a variable integer value, generating a PLL clock signal with a different frequency that avoids occupying the communication channel, thereby reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the PMU is clocked using a frequency whose harmonics fall within the communication channel, then the PMU can operate efficiently, but it couples noise onto the communication channel causing interference
Solution Approach 1:
The patent changes the clocking frequency parameter of the PMU from a fixed frequency to a variable frequency that can be dynamically adjusted. The frequency is changed based on which communication channels are currently in use, so that the PMU clocking frequency and its harmonics never coincide with active communication channels, thereby eliminating noise coupling while maintaining efficient PMU operation
Solution Approach 2:
The patent implements dynamic frequency adjustment of the PMU clocking signal. Instead of using a static clocking frequency, the system dynamically changes the PMU clocking frequency based on real-time communication channel usage. This dynamic adaptation allows the PMU to operate efficiently at different frequencies depending on which communication channels are active, preventing noise interference while maintaining productivity
2Device complexity
If the PMU operates at a fixed frequency, then the design is simple, but the harmonics may fall within communication channels causing interference
Solution Approach 1:
The patent transforms the PMU from using a fixed frequency to using a variable frequency that can be adjusted. This parameter change allows the system to avoid harmonic interference with communication channels while maintaining relatively simple design through the use of a phase-locked loop (PLL) frequency synthesizer and a lookup table for frequency selection
3Object-affected harmful factors
If the PMU clocking frequency is adjusted to avoid communication channels, then noise coupling is reduced, but the system complexity increases
Solution Approach 1:
The patent introduces a phase-locked loop (PLL) frequency synthesizer as an intermediary device between the communication channel usage detection and the PMU clocking. The PLL synthesizer, controlled by a lookup table, automatically generates the appropriate PMU clocking frequency based on which communication channels are in use. This intermediary mechanism handles the complexity of frequency adjustment, reducing noise coupling while managing system complexity through a dedicated frequency synthesis subsystem
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 the use of previously degraded spectrum portions, reducing interference and allowing communication on GSM channels without degrading signal quality.
Implementation Method 1
a phase lock loop (PLL) to multiply the PMU clocking signal by a variable integer value, generating a PLL clock signal with a different frequency
Data Source
AI summary
A communications device is disclosed that implements a phase-locked-loop to multiply a clock signal provided to a power management unit (PMU) by a variable integer value. Multiplying the PMU clock signal provides a second clock signal where the second clock signal is characterized by a fundamental component with one or more harmonics of the fundamental component that differ from the fundamental component and the one or more harmonics of the PMU clock signal. The fundamental component with one or more harmonics of the second clock signal does not occupy the same communication channel as the transmission communication signal of the communications device. Thus, minimizing the degradation of the transmission communication signal.