PSK星座对象（constellation.cc）

BPSK：

constellation_bpsk::constellation_bpsk()
    {
      d_constellation.resize(2);
      d_constellation[0] = gr_complex(-1, 0);
      d_constellation[1] = gr_complex(1, 0);
      d_rotational_symmetry = 2;
      d_dimensionality = 1;
      calc_arity();
    }

QPSK：

constellation_qpsk::constellation_qpsk()
    {
      d_constellation.resize(4);
      // Gray-coded
      d_constellation[0] = gr_complex(-SQRT_TWO, -SQRT_TWO);
      d_constellation[1] = gr_complex(SQRT_TWO, -SQRT_TWO);
      d_constellation[2] = gr_complex(-SQRT_TWO, SQRT_TWO);
      d_constellation[3] = gr_complex(SQRT_TWO, SQRT_TWO);

      /*
        d_constellation[0] = gr_complex(SQRT_TWO, SQRT_TWO);
        d_constellation[1] = gr_complex(-SQRT_TWO, SQRT_TWO);
        d_constellation[2] = gr_complex(SQRT_TWO, -SQRT_TWO);
        d_constellation[3] = gr_complex(SQRT_TWO, -SQRT_TWO);
      */

      d_pre_diff_code.resize(4);
      d_pre_diff_code[0] = 0x0;
      d_pre_diff_code[1] = 0x2;
      d_pre_diff_code[2] = 0x3;
      d_pre_diff_code[3] = 0x1;

      d_rotational_symmetry = 4;
      d_dimensionality = 1;
      calc_arity();
    }

constellation_dqpsk::constellation_dqpsk()
    {
      // This constellation is not gray coded, which allows
      // us to use differential encodings (through diff_encode and
      // diff_decode) on the symbols.
      d_constellation.resize(4);
      d_constellation[0] = gr_complex(+SQRT_TWO, +SQRT_TWO);
      d_constellation[1] = gr_complex(-SQRT_TWO, +SQRT_TWO);
      d_constellation[2] = gr_complex(-SQRT_TWO, -SQRT_TWO);
      d_constellation[3] = gr_complex(+SQRT_TWO, -SQRT_TWO);

      // Use this mapping to convert to gray code before diff enc.
      d_pre_diff_code.resize(4);
      d_pre_diff_code[0] = 0x0;
      d_pre_diff_code[1] = 0x1;
      d_pre_diff_code[2] = 0x3;
      d_pre_diff_code[3] = 0x2;
      d_apply_pre_diff_code = true;

      d_rotational_symmetry = 4;
      d_dimensionality = 1;
      calc_arity();
    }