Duplex Modem

Inheritance diagram of hermespy.modem.modem.DuplexModem

Duplex modems represent the signal processing chain of a communication device simulatenously transmitting and receiving information, implementing the digital signal processing before digital-to-analog conversion and after analog-to-digital conversion, respectively. They are a combination of a Transmitting Modem and a Receiving Modem.

After a DuplexModem is added as a type of Transmitter to a Device, a call to Device.transmit will be delegated to TransmittingModem._transmit(). Similarly, after a DuplexModem is added as a type of Receiver to a Device, a call to Device.receive will be delegated to ReceivingModem._receive()

 1# Initialize a new simulation considering a single device
 2simulation = Simulation()
 3device = simulation.new_device(carrier_frequency=1e10)
 4
 5# Configure the link modeling the devices' transmit DSP
 6modem = DuplexModem()
 7device.add_dsp(modem)
 8
 9# Configure the links's waveform
10waveform = RootRaisedCosineWaveform(
11    oversampling_factor=4,
12    symbol_rate=1e6,
13    num_preamble_symbols=16,
14    num_data_symbols=32,
15    modulation_order=4,
16)
17modem.waveform = waveform

For a detailed description of the transmit and receive routines, refer to the Transmitting Modem and a Receiving Modem of the base classes.

The barebone configuration can be extend by additional components such as Custom Bit Sources, Synchronization, Stream Precoding, Channel Estimation, Symbol Precoding, Channel Equalization and Bit Encoders:

 1# Configure a custom bits source for the modem
 2modem.bits_source = RandomBitsSource(seed=42)
 3
 4# Configure the waveform's synchronization routine
 5modem.waveform.synchronization = SingleCarrierCorrelationSynchronization()
 6
 7# Add a custom stream precoding to the modem
 8modem.transmit_signal_coding[0] = ConventionalBeamformer()
 9modem.receive_signal_coding[0] = ConventionalBeamformer()
10
11# Add a custom symbol precoding to the modem
12modem.transmit_symbol_coding[0] = DFT()
13modem.receive_symbol_coding[0] = DFT()
14
15# Configure the waveform's channel estimation routine
16modem.waveform.channel_estimation = SingleCarrierLeastSquaresChannelEstimation()
17
18# Configure the waveform's channel equalization routine
19modem.waveform.channel_equalization = SingleCarrierZeroForcingChannelEqualization()
20
21# Add forward error correction encodings to the transmitted bit stream
22modem.encoder_manager.add_encoder(RepetitionEncoder(32, 3))
23modem.encoder_manager.add_encoder(BlockInterleaver(192, 32))
class DuplexModem(*args, bits_source=None, selected_transmit_ports=None, selected_receive_ports=None, **kwargs)[source]

Bases: TransmittingModem, ReceivingModem

Representation of a wireless modem simultaneously transmitting and receiving.

Parameters:

  • bits_source (BitsSource, optional) – Source configuration of communication bits transmitted by this modem. Bits are randomly generated by default.

  • selected_transmit_ports (Sequence[int] | None) – Indices of antenna ports selected for transmission from the operated Device's antenna array. If not specified, all available ports will be considered.

  • selected_receive_ports (Sequence[int] | None) – Indices of antenna ports selected for reception from the operated Device's antenna array. If not specified, all available ports will be considered.

  • *args – Modem initialization parameters. Refer to TransmittingModem and ReceivingModem for further details.

  • **kwargs – Modem initialization parameters. Refer to TransmittingModem and ReceivingModem for further details.

yaml_tag: Optional[str] = 'Modem'

YAML serialization tag