Waveform¶

class OrthogonalWaveform(num_subcarriers, grid_resources, grid_structure, pilot_section=None, pilot_sequence=None, repeat_pilot_sequence=True, **kwargs)[source]¶

Bases: ConfigurablePilotWaveform, ABC

Base class for wavforms with orthogonal subcarrier modulation.

Parameters:

num_subcarriers (int) – Number of available orthogonal subcarriers per symbol.
grid_resources (Sequence[GridResource]) – Grid resources available for modulation.
grid_structure (Sequence[GridSection]) – Grid structure of the time-domain.
pilot_section (PilotSection, optional) – Pilot section transmitted at the beginning of each frame.
pilot_sequence (PilotSymbolSequence, optional) – Sequence of pilot / reference symbols.
repeat_pilot_sequence (bool, optional) – Repeat the pilot sequence if it is shorter than the frame.

demodulate(signal)[source]¶

Demodulate a base-band signal stream to data symbols.

Parameters:: signal (np.ndarray) – Vector of complex-valued base-band samples of a single communication frame.
Return type:: Symbols
Returns:: The demodulated communication symbols

map(data_bits)[source]¶

Map a stream of bits to data symbols.

Parameters:: data_bits (np.ndarray) – Vector containing a sequence of L hard data bits to be mapped onto data symbols.
Returns:: Mapped data symbols.
Return type:: Symbols

modulate(symbols)[source]¶

Modulate a stream of data symbols to a base-band signal containing a single data frame.

Parameters:: data_symbols (Symbols) – Singular stream of data symbols to be modulated by this waveform.
Return type:: ndarray

Returns: Samples of the modulated base-band signal.

pick(placed_symbols)[source]¶

Pick the mapped symbols from the communicaton frame.

Additionally removes interleaved pilot symbols.

Parameters:: placed_symbols (StatedSymbols) – The placed symbols.
Return type:: StatedSymbols

Returns: The symbols with the mapped symbols picked from the frame.

place(symbols)[source]¶

Place the mapped symbols within the communicaton frame.

Additionally interleaves pilot symbols.

Parameters:: symbols (Symbols) – The mapped symbols.
Return type:: Symbols

Returns: The symbols with the mapped symbols placed within the frame.

unmap(symbols)[source]¶

Map a stream of data symbols to data bits.

Parameters:: symbols (Symbols) – Sequence of K data symbols to be mapped onto bit sequences.
Returns:: Vector containing the resulting sequence of L data bits In general, L is greater or equal to K.
Return type:: np.ndarray

property bit_energy: float¶

Returns the theoretical average (discrete-time) bit energy of the modulated baseband_signal.

Energy of baseband_signal \(x[k]\) is defined as \(\sum{|x[k]}^2\) Only data bits are considered, i.e., reference, guard intervals are ignored.

property grid_resources: Sequence[GridResource]¶: Available resources within the time-subcarrier grid.

property grid_structure: Sequence[GridSection]¶: Structure of the time-subcarrier grid.

property mapping: PskQamMapping¶: Constellation mapping used to translate bit sequences into complex symbols.

property modulation_order: int¶

Access the modulation order.

Returns:: The modulation order.
Return type:: int

property num_data_symbols: int¶: Number of bit-mapped symbols contained within each communication frame.

property num_subcarriers: int¶

Number of available orthogonal subcarriers.

Raises:: ValueError – If smaller than one.

property pilot_section: PilotSection | None¶

Static pilot section transmitted at the beginning of each OFDM frame.

Required for time-domain synchronization and equalization of carrier frequency offsets.

Returns:: FrameSection of the pilot symbols, None if no pilot is configured.

property pilot_signal: Signal¶

Model of the pilot sequence within this communication waveform.

Returns:: The pilot sequence.
Return type:: Signal

property plot_grid: GridVisualization¶: Visualize the resource grid.

property power: float¶

Returns the theoretical average symbol (unitless) power,

Power of baseband_signal \(x[k]\) is defined as \(\sum_{k=1}^N{|x[k]|}^2 / N\) Power is the average power of the data part of the transmitted frame, i.e., bit energy x raw bit rate

property references_per_frame: int¶: Number of reference symbols per communication frame.

property resource_mask: ndarray¶: Boolean resource mask of the full OFDM frame.

property samples_per_frame: int¶: Number of time-domain samples per processed communication frame.

property symbol_duration: float¶: Duration of a single symbol block.

property symbol_energy: float¶

The theoretical average symbol (discrete-time) energy of the modulated baseband_signal.

Energy of baseband_signal \(x[k]\) is defined as \(\sum{|x[k]}^2\) Only data bits are considered, i.e., reference, guard intervals are ignored.

Returns:: The average symbol energy in UNIT.

property symbols_per_frame: int¶

Number of modulated symbols within each transmitted communication frame.

This includes both data and reference symbols.

property words_per_frame: int¶: Number of words per communication frame.