How is the spread spectrum measured?
Spread Spectrum Measurement with a Spectrum Analyzer The magnitude is the amount of frequency change back and forth. Figure 1 was measured with a Spectrum Analyzer. You can measure the magnitude by the width of the harmonic in the Spectrum Analyzer graph.
What is clock spread spectrum?
Spread spectrum clocking (SSC) is a special way to reduce the radiated emissions of digital clock signals. SSC is the variation of the frequency of a clock signal in a controlled way. In the frequency domain, the SSC reduces the peak amplitude of a digital clock signal by shifting the frequency.
What is spread spectrum clocking PCIE?
Spread Spectrum Clocking (SSC) is a highly effective technique utilized to reduce electromagnetic interference or EMI. PCI Express 5.0 System designers use this tool to reduce the adverse effects on adjacent circuits and to pass FCC or other regulatory body requirements for EMI emissions.
What is spread spectrum in mobile computing?
In other words, “Spread Spectrum is a technique in which the transmitted signals of specific frequencies are varied slightly to obtain greater bandwidth as compared to initial bandwidth.”
What are the two types of spread spectrum techniques?
There are two predominant techniques to spread the spectrum: 1) Frequency hoping (FH), which makes the narrow band signal jump in random narrow bands within a larger bandwidth. 2) Direct sequence (DS) which introduces rapid phase transition to the data to make it larger in bandwidth.
What are the applications of spread spectrum?
Current applications of spread spectrum technology include wireless LANs (local area networks), bar code scanners, and microphones. This technology improves the efficiency and effectiveness of business processes, many of which are finding that wireless communications are requisite for success.
Why is spread spectrum needed?
The main advantage of spread spectrum communication technique is to prevent “interference” whether it is intentional or unintentional. The signals modulated with these techniques are hard to interfere and cannot be jammed. An intruder with no official access is never allowed to crack them.
What is spread spectrum and how does it work?
Spread spectrum is a form of wireless communications in which the frequency of the transmitted signal is deliberately varied. This results in a much greater bandwidth than the signal would have if its frequency were not varied.
What is advantage of spread spectrum technique?
In the spread spectrum technique, the frequency of the signal to be transmitted is varied by injecting pseudo-random noises into it. This injection increases the bandwidth of signal transmission, and thereby reduces the effects of interference, noise, and signal fading.
How is PCIe speed calculated?
Maximum PCIe Bandwidth = SPEED * WIDTH * (1 – ENCODING) – 1Gb/s. For example, a gen 3 PCIe device with x8 width will be limited to: Maximum PCIe Bandwidth = 8G * 8 * (1 – 2/130) – 1G = 64G * 0.985 – 1G = ~62Gb/s.
What is data rate in PCIe?
PCIe 4.0 is twice as fast as PCIe 3.0. PCIe 4.0 has a 16 GT/s data rate, compared to its predecessor’s 8 GT/s. In addition, each PCIe 4.0 lane configuration supports double the bandwidth of PCIe 3.0, maxing out at 32 GB/s in a 16-lane slot, or 64 GB/s with bidirectional travel considered.
What is spread spectrum technique How are they classified?
There are four generic types of spread spectrum signals: Direct Sequence (DS) – The carrier of a DS source stays at a fixed frequency. Narrowband information is spread out into a much larger bandwidth using a pseudo-random chip sequence. Pseudo noise (PN)
What is spread spectrum What are its advantages?
What is spread spectrum clocking and how does it work?
Spread Spectrum Clocking Introduction Spread spectrum clocking is a technique used in electronics design to intentionally modulate the ideal position of the clock edge such that the resulting signal’s spectrum is “spread”, around the ideal frequency of the clock. In timing circuits, this has the advantage of reducing Electromagnetic
What is PCI Express spread spectrum clocking?
For spread-spectrum clocking, the PCI Express spec allows for modulation from 0 to minus-0.5 percent of nominal frequency, with a modulation rate in the range of 30kHz to 33kHz. That is to say, they allow downspreading to minus-5,000ppm, which would take two devices far out of the ±300ppm range.
What is spread-spectrum clock generation (SSCG)?
Spread-spectrum clock generation (SSCG) is used in some synchronous digital systems, especially those containing microprocessors, to reduce the spectral density of the electromagnetic interference (EMI) that these systems
What are spread spectrum techniques in communication?
In telecommunication and radio communication, spread-spectrum techniques are methods by which a signal (e.g., an electrical, electromagnetic, or acoustic signal) generated with a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth.