Symbols (GSM/EDGE/EDGE Evolution)

The Symbols trace displays the raw data bits for each symbol. The first bit in the table corresponds to the first bit of the first symbol in the demodulated Timeslot.

The training sequence bits are highlighted in inverse colors.

When the symbol table marker is enabled, the trace marker highlights the data symbol bits for the selected symbol and the marker readout provides the symbol number and symbol value in decimal. The trace markers can also be coupled so that clicking on a data value in the Symbols trace will move markers on other traces to the location that corresponds to that symbol.

To make the table easier to read, the data bits are shown in groupings of eight characters followed by a space. The characters can represent a binary digit or a hexadecimal digit as specified by the Symbol Table Format parameter. The number to the left of each row indicate either the bit or symbol offset position depending the symbol table format as described below:

Binary Format: The symbol data bit format is binary and each character represents a binary digit. The number to the left of each row indicates the bit offset of the first bit in the row.

Hexadecimal Format: The symbol data bit format is hexadecimal and each character represents a hexadecimal digit. The number to the left of each row indicate the symbol offset of the first symbol in the row.

For example, when the symbol table format is binary and 192 is displayed to the left of third row, the first bit in this row is the 193rd bit in the digital data stream from the demodulated TimeSlot.

There must be at least 4 bits/symbol to use the hexadecimal format. Symbols that have less than 4 bits/symbol (all modulation schemes except 16QAM and 32QAM) will be displayed in binary format regardless of the Symbol Table Format setting.

The following tips will help you to use the Symbol Table:

The symbol data bits can be displayed in either binary or hexadecimal format, see Symbol Table Format.
The binary data can be interpreted as most significant bit first or least significant burst first when converting to hexadecimal or decimal using the Symbol Table Bit Order parameter.
There is always one Timeslot of symbol data in the trace.
Here's an easy way to identify symbol bits and their corresponding symbol points in the constellation diagram: Display IQ Meas Time using the Const format in one grid and the symbol table in another. Then turn on the markers for both traces and enable marker coupling. When the marker is placed on a point in the constellation diagram, the VSA highlights the corresponding symbol bits in the symbol table.
Marker Movement: Use the keyboard arrow keys or the mouse wheel to move the marker from one symbol to the next. You can use the Marker Position - X Position parameter to move the marker to a specific symbol location.