diff options
Diffstat (limited to 'gnuradio-core/src/python/gnuradio/blks2impl/qam.py')
| -rw-r--r-- | gnuradio-core/src/python/gnuradio/blks2impl/qam.py | 31 |
1 files changed, 20 insertions, 11 deletions
diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/qam.py b/gnuradio-core/src/python/gnuradio/blks2impl/qam.py index 20ca6ee89b..143f6e1083 100644 --- a/gnuradio-core/src/python/gnuradio/blks2impl/qam.py +++ b/gnuradio-core/src/python/gnuradio/blks2impl/qam.py @@ -28,6 +28,7 @@ from math import pi, sqrt, log from gnuradio import gr, modulation_utils2 from gnuradio.blks2impl.generic_mod_demod import generic_mod, generic_demod from gnuradio.utils.gray_code import gray_code +from gnuradio.utils import mod_codes # Default number of points in constellation. _def_constellation_points = 16 @@ -35,7 +36,7 @@ _def_constellation_points = 16 _def_differential = True # Whether gray coding is used. If differential is True then gray # coding is used within but not between each quadrant. -_def_gray_coded = True +_def_mod_code = mod_codes.NO_CODE def is_power_of_four(x): v = log(x)/log(4) @@ -52,7 +53,7 @@ def get_bits(x, n, k): # Remove all bits bigger than n+k-1 return v % pow(2, k) -def make_differential_constellation(m, gray_coded=_def_gray_coded): +def make_differential_constellation(m, gray_coded): """ Create a constellation with m possible symbols where m must be a power of 4. @@ -111,7 +112,7 @@ def make_differential_constellation(m, gray_coded=_def_gray_coded): return const_map -def make_not_differential_constellation(m, gray_coded=_def_gray_coded): +def make_not_differential_constellation(m, gray_coded): side = pow(m, 0.5) if (not isinstance(m, int) or m < 4 or not is_power_of_four(m)): raise ValueError("m must be a power of 4 integer.") @@ -145,17 +146,26 @@ def make_not_differential_constellation(m, gray_coded=_def_gray_coded): def qam_constellation(constellation_points=_def_constellation_points, differential=_def_differential, - gray_coded=_def_gray_coded,): + mod_code=_def_mod_code): """ Creates a QAM constellation object. """ + if mod_code == mod_codes.GRAY_CODE: + gray_coded = True + elif mod_code == mod_codes.NO_CODE: + gray_coded = False + else: + raise ValueError("Mod code is not implemented for QAM") if differential: points = make_differential_constellation(constellation_points, gray_coded) else: points = make_not_differential_constellation(constellation_points, gray_coded) side = int(sqrt(constellation_points)) width = 2.0/(side-1) - constellation = gr.constellation_rect(points, side, side, width, width) + # No pre-diff code + # Should add one so that we can gray-code the quadrant bits too. + pre_diff_code = [] + constellation = gr.constellation_rect(points, pre_diff_code, side, side, width, width) return constellation # ///////////////////////////////////////////////////////////////////////////// @@ -166,7 +176,7 @@ class qam_mod(generic_mod): def __init__(self, constellation_points=_def_constellation_points, differential=_def_differential, - gray_coded=_def_gray_coded, + mod_code=_def_mod_code, *args, **kwargs): """ @@ -178,11 +188,11 @@ class qam_mod(generic_mod): See generic_mod block for list of parameters. """ - constellation = qam_constellation(constellation_points, differential, gray_coded) + constellation = qam_constellation(constellation_points, differential, mod_code) # We take care of the gray coding in the constellation generation so it doesn't # need to be done in the block. super(qam_mod, self).__init__(constellation, differential=differential, - gray_coded=False, *args, **kwargs) + *args, **kwargs) # ///////////////////////////////////////////////////////////////////////////// # QAM demodulator @@ -193,7 +203,7 @@ class qam_demod(generic_demod): def __init__(self, constellation_points=_def_constellation_points, differential=_def_differential, - gray_coded=_def_gray_coded, + mod_code=_def_mod_code, *args, **kwargs): """ @@ -204,11 +214,10 @@ class qam_demod(generic_demod): See generic_demod block for list of parameters. """ - constellation = qam_constellation(constellation_points, differential, gray_coded) + constellation = qam_constellation(constellation_points, differential, mod_code) # We take care of the gray coding in the constellation generation so it doesn't # need to be done in the block. super(qam_demod, self).__init__(constellation, differential=differential, - gray_coded=False, *args, **kwargs) # |