Version:

Last Modified: February 7, 2018

Calculates parameters for use with either MT Modulate PAM or MT Demodulate PAM. The node accepts an array of **symbol values** that explicitly specifies the positions of the symbol map with symbols that are evenly distributed between -1 and 1.

An array of symbol values with an index-based order that corresponds to the symbol map. The length of the **symbol values** array must be a positive power of 2, and the entries must be unique and in the range 0 to *M*-1, where *M* is the length of the **symbol values** array.

This node expects an array of integers for the **symbol values** parameter. The integers 0 through (*M*-1) must all be included only once in the **symbol values** array, where *M* is the *M*-ary number of the modulation. The binary representation (LSB first convention) of the integers represents the bit pattern that is mapped to the corresponding symbol location in the **symbol values** array. The symbol locations are evenly spaced between (-1 + 0*i*) and (1 + 0*i*), inclusive, along the real axis (I axis).

For example, for 4-PAM, if you specify **symbol values** as [2 3 0 1], the generated PAM symbol map is [(0.333 + 0*i*), (1 + 0*i*), (-1 + 0*i*), (-0.333 + 0*i*)].

An entry at index *n* is mapped to the PAM symbol map at location 2*n*/(*M* - 1)- 1, where *M* is the size of the PAM constellation. For example, if you specify a **symbol values** array with entries [0, 1, 2, 3], the symbol-to-symbol pairing is * symbol* 0
$\to $ level -1, *symbol* 1
$\to $ level -1/3, *symbol* 2
$\to $ level 1/3, *symbol* 3
$\to $ level 1.

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.

**Default: **No error

Parameter values defining the PAM system. Wire this cluster to the corresponding **system parameters** cluster of MT Modulate PAM or MT Demodulate PAM.

Number of samples per symbol in the modulated output complex waveform. For error-free operation, the **samples per symbol** must be an even number.

An ordered array that maps each symbol to its desired level. The number of PAM levels in the array is 2^{ N }, where *N* is the number of bits per symbol. The vector length for the symbols farthest from the origin is 1.

Number of bits represented by each symbol. This value is equal to Log_{ 2 }(*M*), where *M* is the order of the modulation (for example, for 16-PAM, *M* = 16).

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

**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.

**Where This Node Can Run: **

Desktop OS: Windows

FPGA: Not supported

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