Error Vector 3D (5G NR/5G-Advanced)

There are two types of traces in the Trace > Data > Demod and MIMO Multiple Input, Multiple Output: A physical layer (PHY) configuration in which both transmitter and receiver use multiple antennas. menus that display component carrier data: CCn (component carrier is fixed), and Selected Display CC (component carrier is dynamically selected using the Display parameter). See About Per-Carrier Trace Types for more information.

Error Vector 3D displays a three dimensional representation of the Error Vector Spectrum and Error Vector Time trace data with carriers on the X axis, symbols on the Y axis, and EVM Error vector magnitude (EVM): A quality metric in digital communication systems. See the EVM metric in the Error Summary Table topic in each demodulator for more information on how EVM is calculated for that modulation format. (in %) on the Z axis. While the Error Vector 3D trace combines data displayed in other traces, it is better suited as a visualization tool.

Rotate, Zoom and Pan

You can rotate the 3D model, zoom in and out, and pan to view a particular element of the component carrier.

Rotate - Click and hold the left mouse button to rotate the 3D model.

Zoom - Use the thumb wheel to zoom in and out of the model.

Pan - Ctrl-click and hold to pan left, right, up or down. This is useful with the zoom feature to locate particular elements of the carrier.

Enabling Markers and Resetting the 3D view

Right-click anywhere within the Error Vector 3D trace to display a menu of display options.

Auto Scale - Resets the scale of the 3D model to fit within the trace window without resetting the rotation.

Marker - Adds a marker to the trace and switches to Marker mode. In Marker mode, the cursor changes to cross-hairs, and clicking will relocate the marker to the cursor's position. Click the Pointer tool in the Toolbar to exit Marker mode.

The Error Vector 3D trace supports a single marker (Marker 1) that can be coupled with other traces using Markers > Couple Markers. In Marker mode, clicking on a point in the signal will display marker data at the top of the trace about the selected symbol (carrier number, symbol number, % EVM, channel, modulation and layer). Even though the Mkr: label at the top of the Error Vector 3D trace isn't numbered, it is Marker 1 and will couple to Marker 1 in other traces.

The Error Vector 3D trace's marker data does not appear in the Markers window.

Snap to sym-% - Snaps the 3D rotation to show symbols on the x axis and power (dBm deciBels referenced to a milliWatt: dB relative to 1 milliwatt dissipated in the nominal input impedance of the analyzer) on the Y axis, and auto scales to fit within the trace.

Snap to carrier-% - Snaps the 3D rotation to show carriers on the x axis and power (dBm) on the Y axis, and auto scales to fit within the trace.

Snap to carrier-sym - Snaps the 3D rotation to show carriers on the x axis and symbols on the Y axis, and auto scales to fit within the trace.

Orthographic camera - Displays the model in an orthographic (non-3D) perspective. The orthographic camera renders the planes of each axis using parallel lines, resulting in a "flat" representation of the data. The default view renders the data using 3D (vanishing point) perspective, providing the illusion of depth. In some cases, viewing the error vector data in the orthographic view may be preferred over 3D view.

The Error Vector 3D trace requires a video card and driver that support OpenGL 2.1 or higher for rendering of 3D trace data. See the VSA Installation Guide for a complete list of system requirements.

5G NR demodulation also supports filtering by physical channel type for traces that contain physical channel data. You can use the Trace > Digital Demod > Filtered Channel Types feature to show or hide data by physical channel type as needed.

Filtered Channel Types only appears in the Trace > Digital Demod tab when physical channel data is detected by the selected trace.

Trace Color coding Scheme

A multi-color coding scheme is used to make it easy to visually identify common symbols, subcarriers, and data results within various OFDM Orthogonal Frequency Division Multiplexing: OFDM employs multiple overlapping radio frequency carriers, each operating at a carefully chosen frequency that is Orthogonal to the others, to produce a transmission scheme that supports higher bit rates due to parallel channel operation. OFDM is an alternative tranmission scheme to DSSS and FHSS. Traces. This makes cross trace data comparisons and analysis easier to accomplish. Different colors are assigned to symbols representing elements including: PSS/SSS/PBCH/PBCH_DMRS/PDSCH Physical Downlink Shared Channel/PDSCH_DMRS/PUSCH/PUSCH_DMRS/PUCCH/PUCCH_DMRS. Some common color scheme Traces include: Error Vector Spectrum, Error Vector Time, OFDM Meas, Frame Summary and Slot Summary trace data.

The 5G NR color scheme has been simplified to help make visual sense of a complex standard. The default color assignment for 5G NR follows these general guidelines:

DMRS and PTRS signals
- PTRS and DMRS signals generally are generally assigned cooler colors (greens, blues).
- All DMRS signals share a common color. You can distinguish between DMRS signals using markers, but each DMRS is also visually distinguished by the physical channel in which it is located.
- All PTRS signals share a common color. You can distinguish between PTRS signals using markers, but each PTRS is also visually distinguished by the physical channel in which it is located.
Physical channels (PDCCH, PDSCH, PUCCH, PUSCH, etc.)
- Physical channels are generally assigned warmer colors (yellows, oranges, reds)
- Each physical channel type has an assigned group of colors. For channel collections (multiple channels of the same type), the display will rotate through a group of three similar but distinct colors to distinguish between each channel in the collection. For example, if a signal contains 6 PDSCHs (PDSCH0-5), PDSCH0, PDSCH1 and PDSCH2 will each have similar but uniquely different color assignments. The same colors will be repeated for PDSCH3, PDSCH4 and PDSCH5.

You can also customize and re-assign Trace colors schemes, see the Display Preferences Color tab (click Utilities > Display Preferences > Color tab and select a new color for the active Mod Type element).