Descramble Mode (802.11b/g DSSS/CCK/PBCC)

Menu Path: MeasSetup > IEEE 802.11b/g Demod Properties > Advanced Tab

Default: Refer to DSSS/CCK/PBCC Preset to Standard table

Descramble Mode enable/disables the WLAN WLAN - Wireless Local Area Network: A system that includes the distribution system (DS), access points (APs), and portal entities. It is also the logical location of distribution and integration service functions of an extended service set (ESS). A WLAN system contains one or more APs and zero or more portals in addition to the DS. 802.11b/g descrambler. With this feature, the descrambled or raw data bits for the preamble, header or payload data fields can be viewed separately. The Preamble data bits are shown in the Preamble Syms trace data display, the Header data bits are shown in the Header Syms trace data display and the Payload data bits are shown in the Syms/Errs trace data display:

• On: The Descrambler is ON, the Preamble, Header, and Payload data bits are descrambled.

• OFF: The Descrambler is OFF, the Preamble, Header, and Payload data bits are not descrambled.

• Preamble Only: Only the Preamble data bits are descrambled. The Header data bits and Payload data bits are not descrambled.

• Preamble & Header Only: Only the Preamble and Header data bits are descrambled. The Payload data bits are not descrambled.

Using Descramble Mode

The Descramble Mode demodulation property in conjunction with the Preamble Syms trace data, Header Syms trace data, and Syms/Errs trace data displays provide an easy way to separately validate and/or troubleshoot the signals Preamble, Header and/or Payload data bits.

If the VSA shows the "Could not detect burst type" message, use these features to verify the signal's synchronization bits in the PLCP Physical layer convergence protocol Preamble SYNC field and modulation type bits in the PLCP Header SIGNAL data field.

Note

The Descrambler Mode should generally be set to match the scrambling of the incoming signal. If the input signal has the preamble scrambled, the VSA must descramble the preamble in order to properly sync to the preamble. Similarly, if the input signal has the header scrambled, the VSA must descramble the header in order to properly detect the data modulation type and burst length. If descrambling of the header is disabled, manually specify the Data Modulation Type (MeasSetup > IEEE 802.11b/g Demod Properties > Format tab) and Result Length (MeasSetup > IEEE 802.11b/g Demod Properties > Time tab).

See Also

Advanced Tab (802.11b/g DSSS/CCK/PBCC)

802.11b/g Demod Properties