diff options
Diffstat (limited to 'gr-digital/python/digital/qam.py')
| -rw-r--r-- | gr-digital/python/digital/qam.py | 77 |
1 files changed, 40 insertions, 37 deletions
diff --git a/gr-digital/python/digital/qam.py b/gr-digital/python/digital/qam.py index 518be78941..be4b7efa74 100644 --- a/gr-digital/python/digital/qam.py +++ b/gr-digital/python/digital/qam.py @@ -1,37 +1,40 @@ # # Copyright 2005,2006,2011,2013 Free Software Foundation, Inc. -# +# # This file is part of GNU Radio -# +# # GNU Radio is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 3, or (at your option) # any later version. -# +# # GNU Radio is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. -# +# # You should have received a copy of the GNU General Public License # along with GNU Radio; see the file COPYING. If not, write to # the Free Software Foundation, Inc., 51 Franklin Street, # Boston, MA 02110-1301, USA. -# +# """ QAM modulation and demodulation. """ +from __future__ import absolute_import +from __future__ import division +from __future__ import unicode_literals from math import pi, sqrt, log from gnuradio import gr -from generic_mod_demod import generic_mod, generic_demod -from generic_mod_demod import shared_mod_args, shared_demod_args -from utils.gray_code import gray_code -from utils import mod_codes -import modulation_utils -import digital_swig as digital +from .generic_mod_demod import generic_mod, generic_demod +from .generic_mod_demod import shared_mod_args, shared_demod_args +from .utils.gray_code import gray_code +from .utils import mod_codes +from . import modulation_utils +from . import digital_swig as digital # Default number of points in constellation. _def_constellation_points = 16 @@ -42,7 +45,7 @@ _def_differential = True _def_mod_code = mod_codes.NO_CODE def is_power_of_four(x): - v = log(x)/log(4) + v = log(x) / log(4) return int(v) == v def get_bit(x, n): @@ -52,7 +55,7 @@ def get_bit(x, n): def get_bits(x, n, k): """ Get the k bits of integer x starting at bit n(from little end).""" # Remove the n smallest bits - v = x >> n + v = x >> n # Remove all bits bigger than n+k-1 return v % pow(2, k) @@ -74,7 +77,7 @@ def make_differential_constellation(m, gray_coded): k = int(log(m) / log(2.0)) # First create a constellation for one quadrant containing m/4 points. # The quadrant has 'side' points along each side of a quadrant. - side = int(sqrtm/2) + side = int(sqrtm / 2) if gray_coded: # Number rows and columns using gray codes. gcs = gray_code(side) @@ -83,7 +86,7 @@ def make_differential_constellation(m, gray_coded): else: i_gcs = dict([(i, i) for i in range(0, side)]) # The distance between points is found. - step = 1/(side-0.5) + step = 1 / (side-0.5) gc_to_x = [(i_gcs[gc]+0.5)*step for gc in range(0, side)] @@ -100,7 +103,7 @@ def make_differential_constellation(m, gray_coded): return complex(-gc_to_x[gc_x], -gc_to_x[gc_y]) if quad == 3: return complex(gc_to_x[gc_y], -gc_to_x[gc_x]) - raise StandardError("Impossible!") + raise Exception("Impossible!") # First two bits determine quadrant. # Next (k-2)/2 bits determine x position. @@ -108,8 +111,8 @@ def make_differential_constellation(m, gray_coded): # How x and y relate to real and imag depends on quadrant (see get_c function). const_map = [] for i in range(m): - y = get_bits(i, 0, (k-2)/2) - x = get_bits(i, (k-2)/2, (k-2)/2) + y = get_bits(i, 0, (k-2) // 2) + x = get_bits(i, (k-2) // 2, (k-2) // 2) quad = get_bits(i, k-2, 2) const_map.append(get_c(x, y, quad)) @@ -127,17 +130,17 @@ def make_non_differential_constellation(m, gray_coded): # Get inverse gray codes. i_gcs = mod_codes.invert_code(gcs) else: - i_gcs = range(0, side) + i_gcs = list(range(0, side)) # The distance between points is found. - step = 2.0/(side-1) + step = 2.0 / (side-1) gc_to_x = [-1 + i_gcs[gc]*step for gc in range(0, side)] # First k/2 bits determine x position. # Following k/2 bits determine y position. const_map = [] for i in range(m): - y = gc_to_x[get_bits(i, 0, k/2)] - x = gc_to_x[get_bits(i, k/2, k/2)] + y = gc_to_x[get_bits(i, 0, k // 2)] + x = gc_to_x[get_bits(i, k // 2, k // 2)] const_map.append(complex(x,y)) return const_map @@ -170,7 +173,7 @@ def qam_constellation(constellation_points=_def_constellation_points, else: points = make_non_differential_constellation(constellation_points, gray_coded) side = int(sqrt(constellation_points)) - width = 2.0/(side-1) + width = 2.0 / (side-1) # No pre-diff code # Should add one so that we can gray-code the quadrant bits too. @@ -242,8 +245,8 @@ def large_ampls_to_corners_mapping(side, points, width): sector = real_x * side + imag_x # If this sector is a normal constellation sector then # use the center point. - c = ((real_x-side/2.0+0.5)*width + - (imag_x-side/2.0+0.5)*width*1j) + c = ((real_x-side / 2.0+0.5)*width + + (imag_x-side / 2.0+0.5)*width*1j) if (real_x >= extra_layers and real_x < side-extra_layers and imag_x >= extra_layers and imag_x < side-extra_layers): # This is not an edge row/column. Find closest point. @@ -254,7 +257,7 @@ def large_ampls_to_corners_mapping(side, points, width): sector_values.append(index) return sector_values - + # ///////////////////////////////////////////////////////////////////////////// # QAM modulator # ///////////////////////////////////////////////////////////////////////////// @@ -262,10 +265,10 @@ def large_ampls_to_corners_mapping(side, points, width): class qam_mod(generic_mod): """ Hierarchical block for RRC-filtered QAM modulation. - + The input is a byte stream (unsigned char) and the output is the complex modulated signal at baseband. - + Args: constellation_points: Number of constellation points (must be a power of four) (integer). mod_code: Whether to use a gray_code (digital.mod_codes.GRAY_CODE) or not (digital.mod_codes.NO_CODE). @@ -280,10 +283,10 @@ class qam_mod(generic_mod): *args, **kwargs): """ - Hierarchical block for RRC-filtered QAM modulation. + Hierarchical block for RRC-filtered QAM modulation. - The input is a byte stream (unsigned char) and the - output is the complex modulated signal at baseband. + The input is a byte stream (unsigned char) and the + output is the complex modulated signal at baseband. Args: constellation_points: Number of constellation points. @@ -292,7 +295,7 @@ class qam_mod(generic_mod): if we want gray coding, see digital.utils.mod_codes) See generic_mod block for list of additional parameters. - """ + """ constellation = qam_constellation(constellation_points, differential, mod_code) @@ -309,10 +312,10 @@ class qam_mod(generic_mod): class qam_demod(generic_demod): """ Hierarchical block for RRC-filtered QAM modulation. - + The input is a byte stream (unsigned char) and the output is the complex modulated signal at baseband. - + Args: constellation_points: Number of constellation points (must be a power of four) (integer). mod_code: Whether to use a gray_code (digital.mod_codes.GRAY_CODE) or not (digital.mod_codes.NO_CODE). @@ -327,10 +330,10 @@ class qam_demod(generic_demod): large_ampls_to_corner = False, *args, **kwargs): """ - Hierarchical block for RRC-filtered QAM modulation. + Hierarchical block for RRC-filtered QAM modulation. - The input is a byte stream (unsigned char) and the - output is the complex modulated signal at baseband. + The input is a byte stream (unsigned char) and the + output is the complex modulated signal at baseband. Args: constellation_points: Number of constellation points. |