Available Features (802.11b/g DSSS/CCK/PBCC)

The following topic describes 802.11b/g DSS distribution system service: The set of services provided by the distribution system (DS) that enable the medium access control (MAC) to transport MAC service data units (MSDUs) between stations that are not in direct communication with each other over a single instance of the wireless medium (WM). These services include transport of MSDUs between the access points (APs) of basic service sets (BSSs) within an extended service set (ESS), transport of MSDUs between portals and BSSs within an ESS, and transport of MSDUs between stations in the same BSS in cases where the MSDU has a multicast or broadcast destination address or where the destination is an individual address, but the station sending the MSDU chooses to involve DSS. DSSs are provided between pairs of IEEE 802.11 MACs./CCK complementary code keying/PBCC packet binary convolutional code demodulation features:

802.11b/g DSSS/CCK/PBCC Demodulation Available Features

802.11b/g DSSS/CCK/PBCC Demodulation Limitations

Digital Demod Features not Available for 802.11b/g DSSS/CCK/PBCC Demodulation

802.11b/g DSSS/CCK/PBCC Demodulation Available Features:

One configuration standard preset for IEEE Institute of Electrical and Electronics Engineers. A US-based membership organisation that includes engineers, scientists, and students in electronics and related fields. The IEEE developed the 802 series wired and wireless LAN standards. Visit the IEEE at http://www.ieee.org Std 802.11b and IEEE Std 802.11g DSSS Direct sequence spread spectrum. The data transmission scheme (sometimes referred to as a "'modulation" scheme) used in 802.11b WLANs. DSSS uses a radio transmitter operating at a fixed centre frequency, but using a relatively broad range of frequencies, to spread data transmissions over a fixed range of the frequency band. 802.11a and 802.11g (when not operating in 802.11b mode) use Orthogonal Frequency Division Multiplexing (OFDM)./CCK/PBCC (Wireless LAN Local Area Network: A communications network that serves users within a local geographical area, typically over distances of around 100m. Wireless LANs use wireless communicaitons to network devices so there is no need for data cabling. - Direct Sequence A process of spectrum spreading where the digital information stream is multiplied, using an exclusive OR technique, by a high speed pseudorandom code (spreading sequence) to generate a spread spectrum signal. Spread Spectrum) standard signals.
Support for demodulating the optional IEEE Std 802.11b or IEEE Std 802.11g PBCC modes.
Support for demodulating the preamble of 802.11g DSSS-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. bursts (the OFDM payload can be demodulated using the 802.11a/g/j/p OFDM mode).
Features specific to IEEE 802.11b:
- Analyze variable-length pulses.
- Demodulate long and short preamble formats.
- Automatic and manual pulse length modes.
- Automatic and manual payload data modulation format modes.
- Adjustable chip rate.
- Adjustable chip timing.
- Equalization Filter determined from detected 802.11b preamble information.
- De-spread data results.
- PPDU PLCP Protocol data unit frame Header information (similar to 802.11a/g/j/p OFDM demodulation).
- Ability to disable the descrambler
Pulse Search
Normalize IQ Traces.
Mirrored (flipped) frequency spectrums can be used to remove the effects of high-side mixing or complex conjugation mismatches in simulated data.
Measurement offset and interval (similar to time gating) used to select specific data segments for analysis
Averaging is applicable only in the following circumstances:
- IQ Meas Spec and IQ Ref Spec trace data
- Error Vector Spectrum trace data
- The following averaging types are available for the numeric error summary data and for the pre-demodulated spectrum trace data:
  - RMS (video)
  - RMS Exponential
  - Peak Hold/Continuous Peak Hold

802.11b/g DSSS/CCK/PBCC Demodulation Limitations:

No support for IEEE Std 802.11 FHSS Frequency-hopping spread spectrum is a spread-spectrum technique used by Bluetooth devices and some 802.11 1Mbps/2Mbps WLANs. With FHSS, data is transmitted on a radio carrier which hops pseudo-randomly across several different frequencies at a pre-determined rate and hopping sequence. 802.11b devices use DSSS rather than FHSS. 802.11a and 802.11g devices use OFDM. (Frequency Hopped Spread Spectrum).
No support for IEEE Std 802.11b Channel Agility.

Digital Demod Features not Available for 802.11b/g DSSS/CCK/PBCC Demodulation:

Measurement filter other than None and Raised Cosine
Reference filter other than Rectangular, Gaussian and Raised Cosine
Sync search
Multiple points per Chip/Symbol
Arbitrary constellation rotation