MT Map Symbols to Bits (MT Map MSK Symbols to Bits) (G Dataflow)

Version:

Maps symbols comprised of MSK frequency deviations to an output bit stream based on a user-specified symbol rate.

Programming Patterns
Use this node in conjunction with MT Matched Filter, MT Align to Ideal Symbols, MT Decimate Oversampled Waveform, and MT Calculate BER to perform waveform analysis on the modulated waveform.
Note

The mapping of symbols to bits depends on the number of bits per symbol, which equals ${\mathrm{log}}_{2}\left(M\right)$ with M representing the size of the modulation scheme. For example, in a 256-QAM system, 500 QAM symbols are mapped to $\left(500\right)×{\mathrm{log}}_{2}\left(256\right)=4000\text{\hspace{0.17em}}\text{\hspace{0.17em}}message\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}bits$.

symbols

An array of frequency deviations for one-to-one mapping to the output bit stream.

symbol rate

The symbol rate, in hertz (Hz), of the symbols data.

Note

For MSK modulation, the frequency deviation is ¼ the symbol rate. For nondifferential MSK, the symbol-to-bit mapping is performed by mapping bit 0 $\to$ -0.25 × symbol rate, and mapping bit 1 $\to$ +0.25 × symbol rate.

error in

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Default: No error

differential encoding enable

A value that indicates whether to enable differential encoding of the input symbols prior to mapping to the output bit stream.

Name Description
disable

Disables differential encoding for input symbols.

enable

Enables differential encoding for input symbols.

Default: enable

reset?

A Boolean that determines whether stored state information is cleared on each call to this node.

When the input bit stream is not comprised of an integer number of symbols, the carryover bits are buffered.

 TRUE Clears the buffered data, checks the input parameters on a first call, and reflects any change in the input parameter values during subsequent iterations. FALSE Adds the buffered data to the beginning of data from next iteration, in continuous operations.

Default: TRUE

output bit stream

A bit stream with a one-to-one mapping to the input symbols based on the specified symbol map.

error out

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

Web Server: Not supported in VIs that run in a web application