{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "47ca90c8",
   "metadata": {},
   "outputs": [],
   "source": [
    "%config InlineBackend.figure_format = 'svg'  # don't scale plots\n",
    "\n",
    "from importlib import reload\n",
    "import plot\n",
    "reload(plot)\n",
    "import ubitstr\n",
    "reload(ubitstr)\n",
    "import defs\n",
    "reload(defs)\n",
    "import matplotlib.pyplot as plt\n",
    "import numpy as np\n",
    "import math\n",
    "PI = math.pi"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "2d869a04",
   "metadata": {},
   "source": [
    "# Line Coding\n",
    "\n",
    "## Basic Impulses"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "3d01da95",
   "metadata": {},
   "outputs": [],
   "source": [
    "fig, axes = plt.subplots(1, len(defs.IMPULSES))\n",
    "for ax, impulse in zip(axes, defs.IMPULSES):\n",
    "    plot.impulse(impulse, ax=ax)\n",
    "plt.tight_layout()\n",
    "plt.show()"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "f4342733",
   "metadata": {},
   "source": [
    "## Line Code with Bit Sequence"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "f821ef28",
   "metadata": {},
   "outputs": [],
   "source": [
    "text = \"This was a triumph\\0\"\n",
    "bitstr = ubitstr.from_ascii(text)\n",
    "print(f\"Text          {text}\")\n",
    "print(f\"ASCII encoded {bitstr}\")\n",
    "\n",
    "defs.visualize_ascii(text)\n",
    "\n",
    "linecode_signals = {}\n",
    "for linecode in defs.LINECODES:\n",
    "    print(linecode)\n",
    "    linecode_signals[linecode] = plot.linecode(bitstr, linecode)\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "d9dd5b45",
   "metadata": {},
   "source": [
    "## RZ Inverted Signal Definition"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "301d6c45",
   "metadata": {},
   "outputs": [],
   "source": [
    "print(\"Manchester Regular\")\n",
    "plot.linecode(bitstr, \"RZ\")\n",
    "print(\"Manchester Inverted\")\n",
    "plot.linecode(bitstr, \"RZ\", invert=True)\n",
    "pass"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "9a196fde",
   "metadata": {},
   "source": [
    "## Comparison of Spectrums"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "44417c6a",
   "metadata": {},
   "outputs": [],
   "source": [
    "freq_filter = lambda f: defs.lowpass(f, cutoff=.5)\n",
    "# freq_filter = lambda f: defs.lowpass(f, cutoff=2)\n",
    "\n",
    "\n",
    "linecode_signals[\"NRZ\"] = plot.linecode(bitstr, \"NRZ\")\n",
    "plot.spectrum(linecode_signals[\"NRZ\"])\n",
    "\n",
    "for name, baseband_signal in linecode_signals.items():\n",
    "    print(name)\n",
    "    plot.spectrum(baseband_signal, freq_filter=freq_filter)\n",
    "    plot.filtered(baseband_signal, freq_filter, xscale=1)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "1a91c1d6",
   "metadata": {},
   "source": [
    "## Clock Recovery\n",
    "\n",
    "A schematic example of clock drift and the need for clock synchronization.\n",
    "The receiver clock is slightly faster, so it samples more symbols in the same amount of time than the transmitter sends."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "0af6220b",
   "metadata": {},
   "outputs": [],
   "source": [
    "\n",
    "BITSTR = \"00001010 00000010\"\n",
    "LINECODE = \"Manchester\"\n",
    "DRIFT = 0.1\n",
    "SAMPLING_OFFSET=0.7\n",
    "\n",
    "sampled = plot.linecode(BITSTR, LINECODE)\n",
    "sampled = plot.linecode_drift(BITSTR, LINECODE, drift = DRIFT)\n",
    "sampled = plot.linecode_drift(BITSTR, LINECODE, drift = DRIFT, sampling=True, sampling_offset=SAMPLING_OFFSET)\n",
    "received_bitstr = ubitstr.to_bitstr([s > 0 for s in sampled], n=8)\n",
    "\n",
    "print(f\"Sent:     {BITSTR}\")\n",
    "print(f\"Received: {received_bitstr}\")\n",
    "\n",
    "\n",
    "sampled = plot.linecode_drift(BITSTR, LINECODE, drift = DRIFT, sampling=True, sampling_offset=SAMPLING_OFFSET, repair_clock=True)"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": ".venv (3.13.5)",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.13.5"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 5
}