diff options
Diffstat (limited to 'gr-digital/python/cpm.py')
| -rw-r--r-- | gr-digital/python/cpm.py | 72 |
1 files changed, 31 insertions, 41 deletions
diff --git a/gr-digital/python/cpm.py b/gr-digital/python/cpm.py index 05032336d4..1929a73d30 100644 --- a/gr-digital/python/cpm.py +++ b/gr-digital/python/cpm.py @@ -24,7 +24,8 @@ # See gnuradio-examples/python/digital for examples -from gnuradio import gr, blks2 +from gnuradio import gr, filter +from gnuradio import analog from math import pi import numpy @@ -49,6 +50,31 @@ _def_log = False # ///////////////////////////////////////////////////////////////////////////// class cpm_mod(gr.hier_block2): + """ + Hierarchical block for Continuous Phase modulation. + + The input is a byte stream (unsigned char) representing packed + bits and the output is the complex modulated signal at baseband. + + See Proakis for definition of generic CPM signals: + s(t)=exp(j phi(t)) + phi(t)= 2 pi h int_0^t f(t') dt' + f(t)=sum_k a_k g(t-kT) + (normalizing assumption: int_0^infty g(t) dt = 1/2) + + Args: + samples_per_symbol: samples per baud >= 2 (integer) + bits_per_symbol: bits per symbol (integer) + h_numerator: numerator of modulation index (integer) + h_denominator: denominator of modulation index (numerator and denominator must be relative primes) (integer) + cpm_type: supported types are: 0=CPFSK, 1=GMSK, 2=RC, 3=GENERAL (integer) + bt: bandwidth symbol time product for GMSK (float) + symbols_per_pulse: shaping pulse duration in symbols (integer) + generic_taps: define a generic CPM pulse shape (sum = samples_per_symbol/2) (list/array of floats) + verbose: Print information about modulator? (boolean) + debug: Print modulation data to files? (boolean) + """ + def __init__(self, samples_per_symbol=_def_samples_per_symbol, bits_per_symbol=_def_bits_per_symbol, @@ -60,42 +86,6 @@ class cpm_mod(gr.hier_block2): generic_taps=_def_generic_taps, verbose=_def_verbose, log=_def_log): - """ - Hierarchical block for Continuous Phase - modulation. - - The input is a byte stream (unsigned char) - representing packed bits and the - output is the complex modulated signal at baseband. - - See Proakis for definition of generic CPM signals: - s(t)=exp(j phi(t)) - phi(t)= 2 pi h int_0^t f(t') dt' - f(t)=sum_k a_k g(t-kT) - (normalizing assumption: int_0^infty g(t) dt = 1/2) - - @param samples_per_symbol: samples per baud >= 2 - @type samples_per_symbol: integer - @param bits_per_symbol: bits per symbol - @type bits_per_symbol: integer - @param h_numerator: numerator of modulation index - @type h_numerator: integer - @param h_denominator: denominator of modulation index (numerator and denominator must be relative primes) - @type h_denominator: integer - @param cpm_type: supported types are: 0=CPFSK, 1=GMSK, 2=RC, 3=GENERAL - @type cpm_type: integer - @param bt: bandwidth symbol time product for GMSK - @type bt: float - @param symbols_per_pulse: shaping pulse duration in symbols - @type symbols_per_pulse: integer - @param generic_taps: define a generic CPM pulse shape (sum = samples_per_symbol/2) - @type generic_taps: array of floats - - @param verbose: Print information about modulator? - @type verbose: bool - @param debug: Print modulation data to files? - @type debug: bool - """ gr.hier_block2.__init__(self, "cpm_mod", gr.io_signature(1, 1, gr.sizeof_char), # Input signature @@ -131,13 +121,13 @@ class cpm_mod(gr.hier_block2): # Turn it into symmetric PAM data. - self.pam = gr.chunks_to_symbols_bf(self.sym_alphabet,1) + self.pam = digital_swig.chunks_to_symbols_bf(self.sym_alphabet,1) # Generate pulse (sum of taps = samples_per_symbol/2) if cpm_type == 0: # CPFSK self.taps= (1.0/self._symbols_per_pulse/2,) * self.ntaps elif cpm_type == 1: # GMSK - gaussian_taps = gr.firdes.gaussian( + gaussian_taps = filter.firdes.gaussian( 1.0/2, # gain samples_per_symbol, # symbol_rate bt, # bandwidth * symbol time @@ -153,10 +143,10 @@ class cpm_mod(gr.hier_block2): else: raise TypeError, ("cpm_type must be an integer in {0,1,2,3}, is %r" % (cpm_type,)) - self.filter = blks2.pfb_arb_resampler_fff(samples_per_symbol, self.taps) + self.filter = filter.pfb.arb_resampler_fff(samples_per_symbol, self.taps) # FM modulation - self.fmmod = gr.frequency_modulator_fc(sensitivity) + self.fmmod = analog.frequency_modulator_fc(sensitivity) if verbose: self._print_verbage() |