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bocmod

Binary offset carrier modulation

    Description

    example

    y = bocmod(x,m,n) performs binary offset carrier (BOC) modulation on the input bits x by using a square wave and returns the modulated symbols y. m is the square wave frequency indicator. n is the input bit rate indicator.

    By default, the phasing of the square wave is set to the phase of the sine curve.

    y = bocmod(x,m,n,halfcyclesps) specifies the number of samples per half cycle of the square wave.

    example

    y = bocmod(x,m,n,halfcyclesps,phasing) specifies the phase of the square wave.

    Examples

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    Generate a random stream of input data bits to modulate.

    numBits = 5;
    bits = randi([0,1],numBits,1);

    Set the values of m and n for the subcarrier square wave.

    m = 2; % Square wave frequency is m*1.023e6 Hz
    n = 2; % Square wave input bit rate is n*1.023e6 Hz

    Modulate the input bits with the square wave using the BOC modulation technique.

    sym = bocmod(bits,m,n) % Default phasing is of a sine curve
    sym = 20×1
    
        -1
        -1
         1
         1
        -1
        -1
         1
         1
         1
         1
          ⋮
    
    

    Generate a random stream of input data bits to modulate.

    numBits = 10;
    bits = randi([0,1],numBits,1);

    Set the values of m and n for the subcarrier square wave. Also specify the number of samples per square wave half cycle, spshc.

    m = 5;
    n = 2;
    spshc = 4;

    Modulate the input bits with the square wave using the BOC modulation technique.

    sym = bocmod(bits,m,n,spshc,"cos");

    Input Arguments

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    Input bits, specified as a column vector of binary values.

    The function maps an input bit value of 0 to +1 and an input bit value of 1 to -1. It then multiplies the mapped symbols with a square wave by using the BOC modulation technique.

    Data Types: double | int8 | logical

    Square wave frequency indicator, specified as a positive scalar.

    The frequency of square wave is m*1.023e6 Hz.

    Note

    The value of 2*m/n must always be an integer. This value represents the number of square wave half cycles per input bit, x.

    Data Types: double

    Input bit rate indicator, specified as a positive scalar.

    The input bit rate is n*1.023e6 Hz.

    Data Types: double

    Number of samples per half cycle of the square wave, specified as an integer greater than or equal to 2.

    Data Types: double | uint8

    Phase of the square wave, specified as "sin" or "cos".

    • "sin" — Set the phase of the square wave to the phase of a sine curve.

    • "cos" — Set the phase of the square wave to the phase of a cosine curve.

    Data Types: char | string

    Output Arguments

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    BOC modulated symbols, returned as a column vector. The length of the vector is equal to length(x)*halfcyclesps*2*m/n. If you do not specify halfcyclesps, the value of y is 2 by default.

    The data type of the returned modulated symbols is same as that of the input bits, x.

    Extended Capabilities

    C/C++ Code Generation
    Generate C and C++ code using MATLAB® Coder™.

    Version History

    Introduced in R2022a