WAVECOM W-BitView

 Synchronization, Binary Modulation, Bit Manipulation, Decoding/Equalizer,  CRC and Polynomial, Channel Decoding, Unpacking, Decompression,
 Descrambler, Alphabets, Display Tools,  Analysis Tools, User defined functions

Today, the possibility to analyze and process demodulated signals with un-known protocols is important.

The WAVECOMŪ BitView Tool (W-BV) is an excellent companion to the WAVECOMŪ decoder products. It is a standalone application for analyzing unknown signal; signals with unknown protocols can be further analyzed and processed to retrieve the transmitted data. The software can also be used as a postprocessor for decoded data.

It is possible to import the data stream directly from the W-PCI, W-PCIe, W-CODE, W61 or W51 decoders, or to import data files.

Bit analysis is the process of finding pattern in a seemingly random and incoherent stream of bits. The goal is to transform the bit stream into clear text, or into clean cryptographic text, for further processing. All framing, protocol overhead and checksums, and other extraneous data should be removed. The W-BV pro-vides the user with a set of sophisticated and highly specialized tools to ease and accelerate this process, and facilitate the recovery of useful data.

BitView enables the user to analyze bit streams. The range of available functions includes the display of a bit stream in various formats, simple bit stream manipulations, as well as statistical and mathematical functions, and functions based on coding theory. The tools are directed at users with experience in both coding theory and mathematics; in particular, to understand some of the more complex functions a comprehensive mathematical know-ledge is a requirement.

All analysis steps are logged and saved in an ASCII (XML) format log file, which may be edited with most text editors. Similarly, each processing step, including the necessary parameters involved, is logged, as is each function used and its parameters. The log file may be loaded to repeat the saved analysis steps, which enables analysis sessions to be documented and stored for later automatic rerunning, without user intervention. For complete flexibility, the user may implement their own functions using .NET or MatLab - source code templates are part of the product package.

The initial steps in the bit analysis process depend on what is known about the signal, and on the skill and experience level of the monitor. Prior knowledge of the source, language, frequency, modulation mode, time of capture, etc. are useful pieces of information which may facilitate the analysis of the bit stream.

The various classification tools available from the WAVECOMŪ decoders should then be used. These allow a fully automatic determination of modulation type and coding format, or at least the determination of certain essential parameters of the signal, e.g. baud rate and frequency shift.

Using the autocorrelation function will tell the operator whether the bit stream contains repeating pat-terns, e.g. synchronization words, HDLC flags or start-stop bits.

While the WAVECOMŪ decoders contain a wealth of tools and modes, their focus is on real-time analysis; BitView gives the user the opportunity to analyze and experiment repeatedly with captured data in order to recover the signal content.