End sem 7; week 2 winter session 2025

7th-Semester-Fall-2024/ECOMMS/final-project/dsp.py

@@ -0,0 +1,37 @@
+import scipy as sp
+import numpy as np
+
+
+
+def chunk_samples(samples, num_rows):
+    return samples.reshape((samples.shape[0]//num_rows, num_rows))
+
+
+def db(x):
+    return 10*np.log10(x)
+
+
+def quad_demod(samples):
+    return 0.5*np.angle(samples[:-1] * np.conj(samples[1:]))
+
+
+def lowpass(data, f_cutoff, f_s):
+    nyq = 0.5*f_s
+    normal_cutoff = f_cutoff/nyq
+    b, a = sp.signal.butter(2, normal_cutoff, btype="low", analog=False)
+    y = sp.signal.lfilter(b, a, data)
+    return y
+
+
+def sdr_bandpass(data, f_pass, f_cutoff, extent_MHz):
+
+    lower_extent = extent_MHz[0]*1E6
+    upper_extent = extent_MHz[1]*1E6
+    extent_range = upper_extent - lower_extent
+
+    normal_pass = (f_pass - lower_extent)/extent_range
+    normal_cutoff = (f_cutoff - lower_extent)/extent_range
+
+    b, a = sp.signal.butter(2, (normal_pass, normal_cutoff), btype="bandpass", analog=False)
+    y = sp.signal.lfilter(b, a, data)
+    return y