About the Channel Symbol Table (cdma2000/1xEV-DV)

When cdma2000/1xEV-DV demodulation is enabled, selecting Syms/Errs trace data shows the symbol table and error summary trace data for the specified Walsh Code Number and Walsh Code Length. The bottom section of the display shows the symbol table data and the upper section shows the error summary data. This topic discusses the code channel Symbol Table trace data, the Error Summary trace data is discussed in the Channel Error Summary Data topic.

The Chan Symbol Table shows the binary bits for each measured symbol in the specified Walsh Code Number and Walsh Code Length. These parameters are entered in the Despread Channel Walsh Code Number and Walsh Code Length text boxes, located in the Channel/Layer tab of the cdma2000/1xEV-DV Demod Properties dialog box (MeasSetup > cdma2000/1xEV-DV Demod Properties > Channel/Layer tab).

The first bit in the table corresponds to the first bit of the first symbol. To make the table easier to read, the VSA shows a fixed number of bits (eight), followed by a space.

For Forward link signals, the symbol table has two bits per symbol containing both the "I" and "Q" data.

However, for Reverse link signals, "I" and "Q" data channels are logically separate signals. All trace data contains both the "I" and the "Q" branches of the signal, except the symbol table data. For Reverse signals, the symbol table has one bit per symbol. The bit is either from the "I" branch or the "Q" branch of the channel, as specified by the "IQ" Branch parameter (MeasSetup > cdma2000/1xEV-DV Demod Properties > Channel/Layer tab).

In addition, the VSA shows numbers to the left of each row. These numbers indicate the bit position of the first bit in the row. For example, if 192 are displayed by the third row, the first bit in the row is the 192nd bit in the digital data stream.

Here's an easy way to see the bits that correspond to a point in the channel constellation diagram: display the constellation diagram in one grid, the symbol table in another, and turn on the marker and marker coupling. When the marker is placed on a point in the constellation diagram, the VSA highlights the corresponding bits in the symbol table.

Use the arrow keys on the keyboard or the mouse wheel to move the marker from one symbol to the next. Or use the marker X Position to move to any specified symbol location.

Error Summary Data Information

The error summary data is described in the Channel Error Summary Data topic.