Detecting vibration of a cable of an information handling system
Detecting vibration of a cable including providing a clock signal along a cable, the clock signal is modulated along the cable by a vibration frequency to generate a modulated signal along the cable that includes upper and lower sideband frequencies with respect a frequency of the clock signal; providing the modulated signal to a multiplexer, a positive polarity signal of the modulated signal is provided to a first input line of the multiplexer and a negative polarity signal of the modulated signal is provided to a second input line of the multiplexer; selecting one of the positive polarity signal and the negative polarity signal based on a state of a reference signal; demodulating, based on the selecting, the modulated signal to generate a demodulated signal, including generating the vibration frequency at a baseband of the demodulated signal; filtering the demodulated signal to obtain filtered signal including only the vibration frequency.
1 . A method of detecting vibration of a cable of an information handling system, the method including:
providing a clock signal along a cable, wherein the clock signal is modulated along the cable by a vibration frequency to generate a modulated signal along the cable that includes upper and lower sideband frequencies with respect a frequency of the clock signal;
providing the modulated signal to a multiplexer, wherein a positive polarity signal of the modulated signal is provided to a first input line of the multiplexer and a negative polarity signal of the modulated signal is provided to a second input line of the multiplexer;
selecting one of the positive polarity signal and the negative polarity signal based on a state of a reference signal, including:
when it is determined that the state of the reference signal is high, selecting only the negative polarity signal;
when it is determined that the state of the reference signal is low, selecting only the positive polarity signal, wherein the low reference signal is less than the high reference signal;
demodulating, based on the selecting, the modulated signal to generate a demodulated signal, including generating the vibration frequency at a baseband of the demodulated signal; and
filtering the demodulated signal to obtain a filtered signal including only the vibration frequency.
2 . The method of claim 1 , wherein a frequency of the reference signal is the same as a frequency of the clock signal.
3 . The method of claim 1 , wherein the upper sideband frequency is based on a summation of a frequency of the clock signal and the vibration frequency, and wherein the lower sideband frequency is based on a difference of the frequency of the clock signal and the vibration frequency.
4 . The method of claim 3 , wherein the demodulated signal includes the frequency of the clock signal, the upper sideband frequency, the lower sideband frequency, and the vibration frequency.
5 . The method of claim 1 , further including removing jitter from the reference signal.
6 . The method of claim 1 , further including sampling and converting the filtered signal to generate a single frequency discrete Fourier transform (DFT).
7 . The method of claim 6 , further including:
comparing the single frequency DFT to a threshold;
determining, based on the comparing, that the single frequency DFT is greater than the threshold; and
in response to determining that the single frequency DFT is greater than the threshold, recording the vibration frequency.
8 . The method of claim 7 , further including:
in response to determining that the single frequency DFT is greater than the threshold, adjusting a revolutions per minute (RPM) of a fan of the information handling system, wherein the fan is a source of the vibration frequency.
9 . The method of claim 7 , further including:
in response to determining that the single frequency DFT is greater than the threshold, adjusting a power state of a fan of the information handling system to an off-power state, wherein the fan is a source of the vibration frequency.
10 . An information handling system, including:
a cable;
a clock driver configured to provide a clock signal along the cable, wherein the clock signal is modulated along the cable by a vibration frequency to generate a modulated signal along the cable that includes upper and lower sideband frequencies with respect a frequency of the clock signal;
a multiplexer configured to:
receive the modulated signal, including receiving a positive polarity signal of the modulated signal at a first input line of the multiplexer and a negative polarity signal of the modulated signal at a second input line of the multiplexer,
select one of the positive polarity signal and the negative polarity signal based on a state of a reference signal, including:
when it is determined that the state of the reference signal is high, selecting only the negative polarity signal;
when it is determined that the state of the reference signal is low, selecting only the positive polarity signal, wherein the low reference signal is less than the high reference signal;
demodulate, based in the selecting, the modulated signal to generate a demodulated signal, including generating the vibration frequency at a baseband of the demodulated signal;
a low pass filter configured to filter the demodulated signal to obtain a filtered signal including only the vibration frequency.
11 . The information handling system of claim 10 , wherein a frequency of the reference signal is the same as a frequency of the clock signal.
12 . The information handling system of claim 10 , wherein the upper sideband frequency is based on a summation of a frequency of the clock signal and the vibration frequency, and wherein the lower sideband frequency is based on a difference of the frequency of the clock signal and the vibration frequency.
13 . The information handling system of claim 12 , wherein the demodulated signal includes the frequency of the clock signal, the upper sideband frequency, the lower sideband frequency, and the vibration frequency.
14 . The information handling system of claim 10 , further including:
a clock phase lock loop (PLL) configured to remove jitter from the reference signal.
15 . The information handling system of claim 10 , further including:
a microcontroller unit (MCU) configured to sample and convert the filtered signal to generate a single frequency discrete Fourier transform (DFT).
16 . The information handling system of claim 15 , wherein the MCU is further configured to:
compare the single frequency DFT to a threshold;
determine, based on the comparing, that the single frequency DFT is greater than the threshold; and
in response to determining that the single frequency DFT is greater than the threshold, record the vibration frequency.
17 . The information handling system of claim 16 , wherein the MCU is further configured to:
in response to determining that the single frequency DFT is greater than the threshold, adjust a revolutions per minute (RPM) of a fan of the information handling system, wherein the fan is a source of the vibration frequency.
18 . The information handling system of claim 16 , wherein the MCU is further configured to:
in response to determining that the single frequency DFT is greater than the threshold, adjust a power state of a fan of the information handling system to an off-power state, wherein the fan is a source of the vibration frequency.