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

Version:
    Last Modified: February 7, 2018

    Maps an incoming bit stream to complex-valued QAM symbols.

    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.
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    Note  

    The mapping of symbols to bits depends on the number of bits per symbol, which equals log 2 ( M ) with M representing the size of the modulation scheme. For example, in a 256-QAM system, 500 QAM symbols are mapped to ( 500 ) × log 2 ( 256 ) = 4000 m e s s a g e b i t s .

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    input bit stream

    The incoming bit stream to be mapped to symbols.

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    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).

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    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

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    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

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    symbols

    An array of complex-valued symbols with a one-to-one mapping to the input bit stream based on the specified symbol map.

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    Note  

    Wire this parameter to MT Apply Pulse Shaping Filter to generate the oversampled baseband complex waveform.

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    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


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