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Pulsed Waterfall 3D

The Pulsed Waterfall 3D shows the entire spectrum based on the selected signal duration in 3D. A perfect duration value will offer a 3D view of the fitting signals only:

Pulsed Waterfall 3D Block

Left hand side Input:

  • Spectra


With the PulsedWaterfall 3D block you can identify the duration of any signal live within the frequency spectrum at a glance. It somehow works like an analog tv where you need to tune the sync till you get a stable picture otherwise the picture will scroll up or down the screen. The number of Samples, Persistance, Pulse Duaration, Jitter and Time Compression are adjustable. In addition you can use the "Auto Detect" feature which will try to find the dominant signal duration within the spectrum with a single mouse click:

Pulsed Waterfall 3D Block Settup

A great 3D screenshot showing two channels with a dominant 80 ms pulse duration package looking like a TTI from multiple GSM bases stations. One package is marked with the help of a 3D cursor. In LTE the TTI length is fixed to 1 ms so for sure this must be a UMTS/HSPA transmission which offers a TTI of 2 ms, 10 ms (or 20 ms, 40 ms, 80 ms for some channels), and fixed for a given channel. The Transmission Time Interval (TTI) from a UMTS/HSPA is an interval of time for transmission of one layer 2 data unit (PDU). The TTI comprises the group of blocks of resources for the transmission to which the same coding and modulation is applied:

Pulsed Waterfall 3D Screenshot showing a 80ms pulse duration from some GSM Basestations

The next screenshot shows a WiFi 802.11 signal. The logic detected a signal duration of 1024µs. This is the WiFi 802.11 beacon interval. You often read that beacon frames are sent, by default, every 100 ms, but this is only half of the story: Beacons are sent by the AP at a regular interval defined as the so called "Target Beacon Transmission Time" (TBTT). The TBTT is a time interval measured in time units (TUs). A TU is often mentioned with a duration of 1 ms but this is a bit wrong. The reality is seen in the definition of a time unit within the 802.11-2012 standard document, which reads, "A measurement of time equal to 1024 µs." and this is exacly what we can measure:

Wifi 802.11 Beacon Signal with 1024µs (not 1ms) signal duration

A typical Mission:

Pulsed Waterfall 3D Typical Mission

Please have a look at our latest video showing the usage of this block: Pulsed Waterfall Demo Video