{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Frequency Shift"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "%pylab inline\n",
    "pylab.rcParams['savefig.dpi'] = 300\n",
    "from caf_verilog.freq_shift import FreqShift"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fs = 625e3\n",
    "freq_res = 200\n",
    "n_bits = 8"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "n = np.arange(0,10e3)\n",
    "x = np.exp(2*np.pi*((50e3)/fs)*n*1j)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "Px, ff = psd(x,2**10, fs)\n",
    "plot(ff, 10*np.log10(Px))\n",
    "xlim([0, 100e3])\n",
    "ylim([-80, 0])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fq = FreqShift(x, freq_res, fs, n_bits)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fq.gen_tb(20e3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "max(fq.x_quant.real), min(fq.x_quant.real), max(fq.x_quant.imag), min(fq.x_quant.imag)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "max(x.real), min(x.real), max(x.imag), min(x.imag)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "Px_in, ff_in = psd(fq.x_quant,2**10, fs)\n",
    "plot(ff_in, 10*np.log10(Px_in))\n",
    "xlim([0, 100e3])\n",
    "ylim([-80, 40])\n",
    "savefig('freq_shift_in.png')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Generated Shifted Signal"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from caf_verilog.io_helper import read_complex_output\n",
    "gss = read_complex_output(fq.test_output_filename)\n",
    "sss = read_complex_output(fq.submodules['sig_gen'].test_output_filename)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(len(gss), len(x))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "assert len(gss) == len(x)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "print(gss[:5])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "Px, ff = psd(sss,2**12, fs)\n",
    "plot(ff, 10*np.log10(Px))\n",
    "xlim([15000, 25000])\n",
    "ylim([-80, 20])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "Px_out, ff_out = psd(gss,2**12, fs)\n",
    "plot(ff_out, 10*np.log10(Px_out))\n",
    "xlim([0, 100e3])\n",
    "savefig('freq_shift_out.png')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "f, axarr = plt.subplots(2, sharex=True, gridspec_kw={'hspace': 0})\n",
    "axarr[0].plot(ff_in, 10*np.log10(Px_in))\n",
    "axarr[0].set_xlim([0, 100e3])\n",
    "axarr[0].set_ylim([-80, 40])\n",
    "axarr[1].plot(ff_out, 10*np.log10(Px_out))\n",
    "axarr[1].set_xlim([0, 100e3])\n",
    "axarr[1].set_xlabel('Frequency (Hz)')\n",
    "axarr[0].set_title('Power Spectral Density (dB/Hz)')\n",
    "f.savefig('freq_shift_inout.png')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Generated Negative Shifted Signal"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "%mkdir -p ./neg_shift"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fqn = FreqShift(x, freq_res, fs, 8, neg_shift=True, output_dir='./neg_shift')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fqn.gen_tb(20000)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import os\n",
    "gssn = read_complex_output(os.path.join(fqn.output_dir, fqn.test_output_filename))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "assert len(gssn) == len(x)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "sssn = []\n",
    "for ss in sss:\n",
    "    sssn.append(ss.real + (ss.imag*-1j))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "for ii in range(len(gssn)):\n",
    "    check_res = fqn.x_quant[ii] * sssn[ii]\n",
    "    check_i = int(check_res.real) >> 8\n",
    "    assert gssn[ii].real == check_i\n",
    "    check_q = int(check_res.imag) >> 8\n",
    "    assert gssn[ii].imag == check_q"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "Px, ff = psd(gssn,2**12, fs)\n",
    "plot(ff, 10*np.log10(Px))\n",
    "xlim([0, 100e3])\n",
    "ylim([-80, 40])"
   ]
  }
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