Version:

Last Modified: February 7, 2018

Calculates parameters for use with either MT Modulate PSK or MT Demodulate PSK. This node generates the symbol map for PSK-modulated systems. The node accepts an array of **symbol values** that explicitly specifies the positions of the symbol map.

Example Symbol Map for PSK

This symbol map corresponds to input symbol values {0, 1, 3, 2} for a quadrature-phase-shift-keying (QPSK) modulation system.

An array of symbol values with an order that corresponds to the symbol map. The number of PSK states in the array must be 2^{ N }, where *N* is the number of bits per symbol.

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 generated with equal angles between all *M*-ary symbol locations and a distance of unity from the origin.

For example, in 8-PSK, if you specify **symbol values** as [5 4 2 7 3 0 1 6], the generated PSK symbol map is [(-0.383 - 0.924*i*), (0.383 - 0.924*i*), (-0.383 + 0.924*i*), (-0.924 - 0.383*i*), (0.383 + 0.924*i*), (0.924 + 0.383*i*), (0.924 - 0.383*i*), (-0.924 + 0.383*i*)].

A value that indicates how the PSK modulation represents symbols.

Differential operation is used to implement PSK formats such as differential quadrature PSK (DQPSK) and $\pi $/4-DQPSK.

Name | Description |
---|---|

disable | Symbols are represented as constellation points. |

enable | Symbols are represented as the transitions between constellation points. |

**Default: ****disable**

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

Type of PSK modulation.

Name | Description |
---|---|

normal | Sets the modulation type to regular PSK. |

shifted | Rotates the constellation by $\pi $/M each symbol. |

offset | Sets the modulation type to offset quadrature phase-shift keying (OQPSK). This modulation scheme is a form of phase-shift keying in which four different phase angles are used. This scheme is sometimes referred to as staggered quadrature phase-shift keying (SQPSK). For offset PSK, the ideal symbol timing for Q is offset by 1/2 of a symbol period from the ideal symbol timing for I. |

**Default: ****normal**

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

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 Boolean symbol to its desired coordinates in the complex plane. The number of PSK states in the array must be 2^{ N }, where *N* is the number of bits per symbol.

A value that indicates how the PSK modulation represents symbols.

Differential operation is used to implement PSK formats such as differential quadrature PSK (DQPSK) and $\pi $/4-DQPSK.

Name | Description |
---|---|

disable | Symbols are represented as constellation points. |

enable | Symbols are represented as the transitions between constellation points. |

**Default: ****disable**

Type of PSK modulation.

Name | Description |
---|---|

normal | Sets the modulation type to regular PSK. |

shifted | Rotates the constellation by $\pi $/M each symbol. |

offset | Sets the modulation type to offset quadrature phase-shift keying (OQPSK). This modulation scheme is a form of phase-shift keying in which four different phase angles are used. This scheme is sometimes referred to as staggered quadrature phase-shift keying (SQPSK). For offset PSK, the ideal symbol timing for Q is offset by 1/2 of a symbol period from the ideal symbol timing for I. |

**Default: ****normal**

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-PSK, *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