# MT Map Symbols to Bits (MT Map QAM Symbols to Bits) (G Dataflow)

Version:

Maps complex-valued QAM symbols to an output bit stream based on a user-specified symbol map.

##### 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

The incoming complex-valued symbols to be mapped to the output bit stream based on the symbol map.

## symbol map

An ordered array that maps each symbol value to its desired coordinates in the complex plane.

The number of QAM states in the array must be 2 N , where N is the number of bits per symbol. The length of the vector for the symbols farthest from the origin must be 1. To specify a prebuilt map, unbundle the symbol map element from the QAM system parameters cluster generated by MT Generate QAM System Parameters (M) or MT Generate QAM System Parameters (map).

## 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

## 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