Rename and refactor demo pages for clarity; add new Pulse shaping page

demo/index.py

@@ -1,53 +1,18 @@
 import streamlit as st
 
-# Local import
+# local import
 from utils import show_about
 
 st.set_page_config(page_title="Komm Demo", layout="wide")
 
-
 st.title("Komm Demo")
 
 st.markdown(
     """
-    This interactive demo showcases various features of the Komm library, a toolkit for analysis and simulation of analog and digital communication systems.
+    This interactive demo showcases various features of the [Komm library](https://komm.dev).
+
+    Please select a page from the sidebar to get started.
     """
 )
 
-st.header("Available demos")
-
-col1, col2 = st.columns(2)
-
-with col1:
-    st.subheader("1. Binary sequences")
-    st.markdown(
-        """
-        Explore different types of binary sequences commonly used in communications:
-        - Barker sequencesfrom st_pages import Page, add_page_title, show_pages
-        - Walsh-Hadamard sequences
-        - Linear-feedback shift register (LFSR) sequences
-        """
-    )
-
-    st.subheader("2. Constellations")
-    st.markdown(
-        """
-        Interactive visualization of digital modulation constellations:
-        - Phase-shift keying (PSK)
-        - Quadrature amplitude modulation (QAM)
-        """
-    )
-
-with col2:
-    st.subheader("3. Pulse formatting")
-    st.markdown(
-        """
-        Visualize various pulse shaping techniques:
-        - Sinc pulse
-        - Raised cosine pulse
-        - Gaussian pulse
-        """
-    )
-
-
 show_about()

demo/pages/1_Binary_sequences.py → demo/pages/Binary_sequences.py

@@ -2,7 +2,7 @@
 import numpy as np
 import streamlit as st
 
-# Local import
+# local import
 from utils import show_about, show_code, show_documentation
 
 import komm

demo/pages/2_Constellations.py → demo/pages/Modulation.py

@@ -2,7 +2,7 @@
 import numpy as np
 import streamlit as st
 
-# Local import
+# local import
 from utils import show_about, show_code, show_documentation
 
 import komm

demo/pages/Pulse_shaping.py

@@ -0,0 +1,67 @@
+import matplotlib.pyplot as plt
+import numpy as np
+import numpy.fft as fft
+import streamlit as st
+
+import komm
+
+st.set_page_config(page_title="Raised Cosine Pulse", layout="wide")
+
+st.title("Pulse shaping")
+st.header("Raised cosine pulse")
+
+cols = st.columns(3)
+with cols[0]:
+    rolloff = st.slider(
+        "Roll-off factor",
+        min_value=0.0,
+        max_value=1.0,
+        value=0.25,
+        step=0.01,
+    )
+with cols[1]:
+    samples_per_symbol = st.slider(
+        "Samples per symbol",
+        min_value=2,
+        max_value=32,
+        value=16,
+        step=2,
+    )
+with cols[2]:
+    truncation = st.slider(
+        "Truncation",
+        min_value=2,
+        max_value=16,
+        value=8,
+        step=2,
+    )
+
+seq = [1, -1, 1, 1, -1, -1, 1]
+
+pulse = komm.RaisedCosinePulse(rolloff=rolloff)
+tx_filter = komm.TransmitFilter(
+    pulse,
+    samples_per_symbol=samples_per_symbol,
+    truncation=truncation,
+)
+t = tx_filter.time(seq)
+waveform = tx_filter(seq)
+spectrum = fft.fftshift(fft.fft(waveform, 1024)) / samples_per_symbol
+
+fig, (ax0, ax1) = plt.subplots(1, 2, figsize=(12, 5))
+ax0.stem(seq, linefmt="r", markerfmt="ro")
+ax0.plot(t, waveform, "o-", markersize=2)
+ax0.axis((-3, 9, -2, 2))
+ax0.set_xlabel("$t$")
+ax0.set_ylabel("$y(t)$")
+ax0.grid()
+
+f = np.linspace(-0.5, 0.5, 1024, endpoint=False)
+ax1.plot(f, np.abs(spectrum))
+ax1.axis((-0.5, 0.5, -0.5, 4.5))
+ax1.set_xlabel("$f$")
+ax1.set_ylabel("$|\\hat{y}(f)|$")
+ax1.grid()
+
+
+st.pyplot(fig)