34 lines
984 B
Python
34 lines
984 B
Python
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#!/usr/bin/env python3
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import numpy as np
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def rrc_design(N, samples_per_symbol, roll_off = 0.35):
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coef = np.zeros(N)
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k0 = N/2
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Ts = samples_per_symbol
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for k in range(len(coef)):
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t = k - k0
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if t == 0:
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coef[k] = 1 / np.sqrt(Ts) * (1 - roll_off + 4 * roll_off / np.pi)
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elif abs(t) == (Ts / (4*roll_off)):
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coef[k] = roll_off / np.sqrt(2 * Ts) * \
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( (1 + 2/np.pi) * np.sin(np.pi / (4 * roll_off)) + \
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(1 - 2/np.pi) * np.cos(np.pi / (4 * roll_off)) )
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else:
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coef[k] = 1 / np.sqrt(Ts) * \
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( np.sin(np.pi * t / Ts * (1 - roll_off)) + 4 * roll_off * t / Ts * np.cos(np.pi * t / Ts * (1 + roll_off)) ) / \
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( np.pi * t / Ts * (1 - (4 * roll_off * t / Ts)**2) )
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return coef
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if __name__ == "__main__":
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import matplotlib.pyplot as pp
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c = rrc_design(50, 5, 0.35)
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print(np.sum(c))
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pp.plot(c)
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pp.show()
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