gnuradio.digital: Constellations

gnuradio.digital.constellation_8psk() → sptr

Digital constellation for 8PSK.

Constructor Specific Documentation:

gnuradio.digital.constellation_bpsk() → sptr

Digital constellation for BPSK.

Constructor Specific Documentation:

gnuradio.digital.constellation_calcdist(std::vector<(gr_complex, std::allocator<(gr_complex)>)> constell, __dummy_5__ pre_diff_code, unsigned int rotational_symmetry, unsigned int dimensionality) → sptr

Calculate Euclidian distance for any constellation

Constellation which calculates the distance to each point in the constellation for decision making. Inefficient for large constellations.

Constructor Specific Documentation:

Parameters:

• constell –
• pre_diff_code –
• rotational_symmetry –
• dimensionality –

gnuradio.digital.constellation_dqpsk() → sptr

Digital constellation for DQPSK.

Constructor Specific Documentation:

gnuradio.digital.constellation_psk(std::vector<(gr_complex, std::allocator<(gr_complex)>)> constell, __dummy_5__ pre_diff_code, unsigned int n_sectors) → sptr

constellation_psk

Constellation space is divided into pie slices sectors.

Each slice is associated with the nearest constellation point.

Works well for PSK but nothing else.

Assumes that there is a constellation point at 1.x

Constructor Specific Documentation:

Parameters:

• constell –
• pre_diff_code –
• n_sectors –

gnuradio.digital.constellation_qpsk() → sptr

Digital constellation for QPSK.

Constructor Specific Documentation:

gnuradio.digital.constellation_rect(std::vector<(gr_complex, std::allocator<(gr_complex)>)> constell, __dummy_5__ pre_diff_code, unsigned int rotational_symmetry, unsigned int real_sectors, unsigned int imag_sectors, float width_real_sectors, float width_imag_sectors) → sptr

Rectangular digital constellation

Only implemented for 1-(complex)dimensional constellation.

Constellation space is divided into rectangular sectors. Each sector is associated with the nearest constellation point.

Works well for square QAM.

Works for any generic constellation provided sectors are not too large.

Constructor Specific Documentation:

Parameters:

• constell –
• pre_diff_code –
• rotational_symmetry –
• real_sectors –
• imag_sectors –
• width_real_sectors –
• width_imag_sectors –

gnuradio.digital.qpsk.qpsk_constellation(mod_code='gray')

Creates a QPSK constellation.

gnuradio.digital.psk.psk_constellation(m=4, mod_code='gray', differential=True)

Creates a PSK constellation object.

gnuradio.digital.qam.qam_constellation(constellation_points=16, differential=True, mod_code='none', large_ampls_to_corners=False)

Creates a QAM constellation object.

If large_ampls_to_corners=True then sectors that are probably occupied due to a phase offset, are not mapped to the closest constellation point. Rather we take into account the fact that a phase offset is probably the problem and map them to the closest corner point. It’s a bit hackish but it seems to improve frequency locking.