Module DigiCommPy.signalgen

Signal generating functions

@author: Mathuranathan Viswanathan Created on Jul 15, 2019

"""
Signal generating functions

@author: Mathuranathan Viswanathan
Created on Jul 15, 2019
"""
import numpy as np

def sine_wave(f,overSampRate,phase,nCyl):
    """
    Generate sine wave signal with the following parameters
    Parameters:
        f : frequency of sine wave in Hertz
        overSampRate : oversampling rate (integer)
        phase : desired phase shift in radians
        nCyl : number of cycles of sine wave to generate
    Returns:
        (t,g) : time base (t) and the signal g(t) as tuple    
    Example:
        f=10; overSampRate=30;
        phase = 1/3*np.pi;nCyl = 5;
        (t,g) = sine_wave(f,overSampRate,phase,nCyl)
    """
    fs = overSampRate*f # sampling frequency
    t = np.arange(0,nCyl*1/f-1/fs,1/fs) # time base    
    g = np.sin(2*np.pi*f*t+phase) # replace with cos if a cosine wave is desired    
    return (t,g) # return time base and signal g(t) as tuple

def square_wave(f,overSampRate,nCyl):
    """
    Generate square wave signal with the following parameters
    Parameters:
        f : frequency of square wave in Hertz
        overSampRate : oversampling rate (integer)
        nCyl : number of cycles of square wave to generate
    Returns:
        (t,g) : time base (t) and the signal g(t) as tuple    
    Example:
        f=10; overSampRate=30;nCyl = 5;
        (t,g) = square_wave(f,overSampRate,nCyl)
    """
    fs = overSampRate*f # sampling frequency
    t = np.arange(0,nCyl*1/f-1/fs,1/fs) # time base    
    g = np.sign(np.sin(2*np.pi*f*t)) # replace with cos if a cosine wave is desired    
    return (t,g) # return time base and signal g(t) as tuple

def rect_pulse(A,fs,T):
    """
    Generate isolated rectangular pulse with the following parameters
    Parameters:
        A : amplitude of the rectangular pulse
        fs : sampling frequency in Hz
        T : duration of the pulse in seconds
    Returns:
        (t,g) : time base (t) and the signal g(t) as tuple 
    Example:
        A = 1; fs=500;T = 0.2;
        (t,g) = rect_pulse(A,fs,T)
    """
    t = np.arange(-0.5,0.5,1/fs) # time base
    rect = (t >-T/2) * (t<T/2) + 0.5*(t==T/2) + 0.5*(t==-T/2)
    g = A*rect
    return (t,g)

def gaussian_pulse(fs,sigma):
    """
    Generate isolated Gaussian pulse with the following parameters
    Parameters:
        fs : sampling frequency in Hz
        sigma : pulse width in seconds
    Returns:
        (t,g) : time base (t) and the signal g(t) as tuple
    Example:
        fs = 80; sigma = 0.1;
        (t,g) = gaussian_pulse(fs,sigma)
    """
    t = np.arange(-0.5,0.5,1/fs) # time base
    g = 1/(np.sqrt(2*np.pi)*sigma)*(np.exp(-t**2/(2*sigma**2)))
    return(t,g) # return time base and signal g(t) as tuple

Functions

def gaussian_pulse(fs, sigma)

Generate isolated Gaussian pulse with the following parameters

Parameters

fs : sampling frequency in Hz

 

sigma : pulse width in seconds

 

Returns

(t,g) : time base (t) and the signal g(t) as tuple

Example

fs = 80; sigma = 0.1; (t,g) = gaussian_pulse(fs,sigma)

Expand source code

def gaussian_pulse(fs,sigma):
    """
    Generate isolated Gaussian pulse with the following parameters
    Parameters:
        fs : sampling frequency in Hz
        sigma : pulse width in seconds
    Returns:
        (t,g) : time base (t) and the signal g(t) as tuple
    Example:
        fs = 80; sigma = 0.1;
        (t,g) = gaussian_pulse(fs,sigma)
    """
    t = np.arange(-0.5,0.5,1/fs) # time base
    g = 1/(np.sqrt(2*np.pi)*sigma)*(np.exp(-t**2/(2*sigma**2)))
    return(t,g) # return time base and signal g(t) as tuple

def rect_pulse(A, fs, T)

Generate isolated rectangular pulse with the following parameters

Parameters

A : amplitude of the rectangular pulse

 

fs : sampling frequency in Hz

 

T : duration of the pulse in seconds

 

Returns

(t,g) : time base (t) and the signal g(t) as tuple

Example

A = 1; fs=500;T = 0.2; (t,g) = rect_pulse(A,fs,T)

Expand source code

def rect_pulse(A,fs,T):
    """
    Generate isolated rectangular pulse with the following parameters
    Parameters:
        A : amplitude of the rectangular pulse
        fs : sampling frequency in Hz
        T : duration of the pulse in seconds
    Returns:
        (t,g) : time base (t) and the signal g(t) as tuple 
    Example:
        A = 1; fs=500;T = 0.2;
        (t,g) = rect_pulse(A,fs,T)
    """
    t = np.arange(-0.5,0.5,1/fs) # time base
    rect = (t >-T/2) * (t<T/2) + 0.5*(t==T/2) + 0.5*(t==-T/2)
    g = A*rect
    return (t,g)

def sine_wave(f, overSampRate, phase, nCyl)

Generate sine wave signal with the following parameters

Parameters

f : frequency of sine wave in Hertz

 

overSampRate : oversampling rate (integer)

 

phase : desired phase shift in radians

 

nCyl : number of cycles of sine wave to generate

 

Returns

(t,g) : time base (t) and the signal g(t) as tuple

Example

f=10; overSampRate=30; phase = 1/3*np.pi;nCyl = 5; (t,g) = sine_wave(f,overSampRate,phase,nCyl)

Expand source code

def sine_wave(f,overSampRate,phase,nCyl):
    """
    Generate sine wave signal with the following parameters
    Parameters:
        f : frequency of sine wave in Hertz
        overSampRate : oversampling rate (integer)
        phase : desired phase shift in radians
        nCyl : number of cycles of sine wave to generate
    Returns:
        (t,g) : time base (t) and the signal g(t) as tuple    
    Example:
        f=10; overSampRate=30;
        phase = 1/3*np.pi;nCyl = 5;
        (t,g) = sine_wave(f,overSampRate,phase,nCyl)
    """
    fs = overSampRate*f # sampling frequency
    t = np.arange(0,nCyl*1/f-1/fs,1/fs) # time base    
    g = np.sin(2*np.pi*f*t+phase) # replace with cos if a cosine wave is desired    
    return (t,g) # return time base and signal g(t) as tuple

def square_wave(f, overSampRate, nCyl)

Generate square wave signal with the following parameters

Parameters

f : frequency of square wave in Hertz

 

overSampRate : oversampling rate (integer)

 

nCyl : number of cycles of square wave to generate

 

Returns

(t,g) : time base (t) and the signal g(t) as tuple

Example

f=10; overSampRate=30;nCyl = 5; (t,g) = square_wave(f,overSampRate,nCyl)

Expand source code

def square_wave(f,overSampRate,nCyl):
    """
    Generate square wave signal with the following parameters
    Parameters:
        f : frequency of square wave in Hertz
        overSampRate : oversampling rate (integer)
        nCyl : number of cycles of square wave to generate
    Returns:
        (t,g) : time base (t) and the signal g(t) as tuple    
    Example:
        f=10; overSampRate=30;nCyl = 5;
        (t,g) = square_wave(f,overSampRate,nCyl)
    """
    fs = overSampRate*f # sampling frequency
    t = np.arange(0,nCyl*1/f-1/fs,1/fs) # time base    
    g = np.sign(np.sin(2*np.pi*f*t)) # replace with cos if a cosine wave is desired    
    return (t,g) # return time base and signal g(t) as tuple