fun_ofdm  1.0
802.11a Physical Layer for USRP
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fun::modulator Class Reference

The modulator class. More...

#include <modulator.h>

Static Public Member Functions

static std::vector
< std::complex< double > > 		modulate (std::vector< unsigned char > data, Rate rate)
 Modulates the data. More...
 
static std::vector< unsigned char > demodulate (std::vector< std::complex< double > > data, Rate rate)
 Demodulates the data. More...
 

Detailed Description

The modulator class.

The modulator takes the input data in bits and converts it to complex doubles representing the digital modulation symbols and vice versa. Supported Modulations are: -BPSK -QPSK -16 QAM -64 QAM

Definition at line 35 of file modulator.h.

Member Function Documentation

std::vector< unsigned char > fun::modulator::demodulate ( std::vector< std::complex< double > >  data,
Rate  rate 
)
static

Demodulates the data.

Parameters
dataVector of data to be demodulated in complex doubles.
ratePHY transmission frate from which the type of modulation is extracted.
Returns
Vector of demodulated data in bytes.

Demodulates the input data vector using one of the following modulations based on the given rate: -BPSK -QPSK -16 QAM -64 QAM

Definition at line 108 of file modulator.cpp.

References fun::RateParams::bpsc, fun::QAM< NumBits >::decode(), fun::RATE_1_2_BPSK, fun::RATE_1_2_QAM16, fun::RATE_1_2_QPSK, fun::RATE_2_3_BPSK, fun::RATE_2_3_QAM16, fun::RATE_2_3_QAM64, fun::RATE_2_3_QPSK, fun::RATE_3_4_BPSK, fun::RATE_3_4_QAM16, fun::RATE_3_4_QAM64, and fun::RATE_3_4_QPSK.

Referenced by fun::ppdu::decode_data(), and fun::ppdu::decode_header().

109  {
110  RateParams rp = RateParams(rate);
111 
112  // Demodulate the data
113  int coded_bit_count = data.size();
114  std::vector<unsigned char>data_demodulated(coded_bit_count * rp.bpsc, 0);
115  switch(rate)
116  {
117  // BPSK
118  case RATE_1_2_BPSK: case RATE_2_3_BPSK: case RATE_3_4_BPSK:
119  {
120  QAM<1> bpsk(1.0);
121  for(int s = 0; s < coded_bit_count; s++)
122  bpsk.decode(data[s].real(), &data_demodulated[s]);
123  break;
124  }
125 
126  // QPSK
127  case RATE_1_2_QPSK: case RATE_2_3_QPSK: case RATE_3_4_QPSK:
128  {
129  QAM<1> qpsk(0.5);
130  for(int s = 0; s < coded_bit_count; s++)
131  {
132  qpsk.decode(data[s].real(), &data_demodulated[s*2]);
133  qpsk.decode(data[s].imag(), &data_demodulated[s*2+1]);
134  }
135  break;
136  }
137 
138  // QAM16
139  case RATE_1_2_QAM16: case RATE_2_3_QAM16: case RATE_3_4_QAM16:
140  {
141  QAM<2> qam16(0.5);
142  for(int s = 0; s < coded_bit_count; s++)
143  {
144  qam16.decode(data[s].real(), &data_demodulated[s*4]);
145  qam16.decode(data[s].imag(), &data_demodulated[s*4+2]);
146  }
147  break;
148  }
149 
150  // QAM64
151  case RATE_2_3_QAM64: case RATE_3_4_QAM64:
152  {
153  QAM<3> qam64(0.5);
154  for(int s = 0; s < coded_bit_count; s++)
155  {
156  qam64.decode(data[s].real(), &data_demodulated[s*6]);
157  qam64.decode(data[s].imag(), &data_demodulated[s*6+3]);
158  }
159  break;
160  }
161  }
162 
163  return data_demodulated;
164  }
std::vector< std::complex< double > > fun::modulator::modulate ( std::vector< unsigned char >  data,
Rate  rate 
)
static

Modulates the data.

Parameters
dataVector of data in bytes to be modulated.
ratePHY transmission rate from which the type of modulation is extracted.
Returns
Vector of modulated data as complex doubles.

Modulates the input data vector using one of the following modulations based on the given rate: -BPSK -QPSK -16 QAM -64 QAM

Definition at line 29 of file modulator.cpp.

References fun::QAM< NumBits >::encode(), fun::RATE_1_2_BPSK, fun::RATE_1_2_QAM16, fun::RATE_1_2_QPSK, fun::RATE_2_3_BPSK, fun::RATE_2_3_QAM16, fun::RATE_2_3_QAM64, fun::RATE_2_3_QPSK, fun::RATE_3_4_BPSK, fun::RATE_3_4_QAM16, fun::RATE_3_4_QAM64, and fun::RATE_3_4_QPSK.

Referenced by fun::ppdu::encode_data(), and fun::ppdu::encoder_header().

30  {
31  // Modualate the data
32  int modulated_sample_count = data.size();
33  std::vector<double> data_mod_buffer;
34  switch(rate)
35  {
36  // BPSK
37  case RATE_1_2_BPSK: case RATE_2_3_BPSK: case RATE_3_4_BPSK:
38  {
39  QAM<1> bpsk(1.0);
40  data_mod_buffer = std::vector<double>(modulated_sample_count * 2, 0);
41  for(int x = 0; x < modulated_sample_count; x++)
42  {
43  bpsk.encode((const char *)&data[x], &data_mod_buffer[x*2]);
44  }
45 
46  break;
47  }
48 
49  // QPSK
50  case RATE_1_2_QPSK: case RATE_2_3_QPSK: case RATE_3_4_QPSK:
51  {
52  QAM<1> qpsk(0.5);
53  modulated_sample_count /= 2;
54  data_mod_buffer = std::vector<double>(modulated_sample_count * 2, 0);
55  for(int x = 0; x < modulated_sample_count; x++)
56  {
57  qpsk.encode((const char *)&data[x*2], &data_mod_buffer[x*2]);
58  qpsk.encode((const char *)&data[x*2+1], &data_mod_buffer[x*2+1]);
59  }
60 
61  break;
62  }
63 
64  // QAM16
65  case RATE_1_2_QAM16: case RATE_2_3_QAM16: case RATE_3_4_QAM16:
66  {
67  QAM<2> qam16(0.5);
68  modulated_sample_count /= 4;
69  data_mod_buffer = std::vector<double>(modulated_sample_count * 2, 0);
70  for(int x = 0; x < modulated_sample_count; x++)
71  {
72  qam16.encode((const char *)&data[x*4], &data_mod_buffer[x*2]);
73  qam16.encode((const char *)&data[x*4+2], &data_mod_buffer[x*2+1]);
74  }
75 
76  break;
77  }
78 
79  // QAM64
80  case RATE_2_3_QAM64: case RATE_3_4_QAM64:
81  {
82  QAM<3> qam64(0.5);
83  modulated_sample_count /= 6;
84  data_mod_buffer = std::vector<double>(modulated_sample_count * 2, 0);
85  for(int x = 0; x < modulated_sample_count; x++)
86  {
87  qam64.encode((const char *)&data[x*6], &data_mod_buffer[x*2]);
88  qam64.encode((const char *)&data[x*6+3], &data_mod_buffer[x*2+1]);
89  }
90 
91  break;
92  }
93  }
94 
95  std::vector<std::complex<double> > modulated_data(data_mod_buffer.size() / 2);
96  memcpy(&modulated_data[0], &data_mod_buffer[0], modulated_data.size() * sizeof(std::complex<double>));
97  return modulated_data;
98  }
The documentation for this class was generated from the following files: