Analog Beamforming
Demapper class is used for demodulating the estimated “qam”, “bpsk” or “
Max-log-MAP: Sub-optimal (3dB performance loss for AWGN channel) but has an order lower complexity than Log-MAP. It is configured using
demapping_method
= “maxlog”Log-MAP: Optimal performance for AWGN channels. It is configured using
demapping_method
= “app”
The decoder can be configured to return soft or hard output by using hard_out
flag. The demapper for “qam” methods is
imported from Sionna-demapper.
Important
When the output of demapper is passed to a channel coder or descrambler, the channel coder should be configured to either accept the hard inputs or the hard inputs must be converted to bipolar
format.
The demapping is performed as follows:
Log-MAP bpsk Demapper generating soft output:
demapMethod = "app" # Demapping method
constType = "bpsk" # Symbol mapping type
modOrder = 1 # Mordulation order or number of bits per symbol
hard_out = False # Whether to return hard output or soft output
# Symbol demapping object
demapper = Demapper(demapMethod, constType, modOrder, hard_out = hard_out)
llr = demapper([symbols, 1/snr]) # LLR Computation
Max-Log-MAP QAM Demapping generating hard output:
demapMethod = "maxlog" # Demapping method
constType = "qam" # Symbol mapping type
modOrder = 4 # Mordulation order or number of bits per symbol
hard_out = True # Whether to return hard output or soft output
# Symbol demapping object
demapper = Demapper(demapMethod, constType, modOrder, hard_out = hard_out)
bitEst = demapper([symbols, 1/snr]) # LLR Computation
The details about the input-output interface of the Symbol demapper detailed below.
- class toolkit5G.MIMOProcessing.AnalogBeamforming(carrierFrequency, isCustomBeamformer=True)[source]
The module implements the analog beamforming.
- Parameters:
carrierFrequency (float) – Defines the carrier frequency.
isCustomBeamformer (bool) – Flag to indicate whether the custom beamformer is passed.
- Input:
x_time ((…,)) – Defines the signal to be beamformed.
Pt_dBm (float) – Defines the power in dBm.
args (list) – Defines the parameters related beamforming. * If
isCustomBeamformer
isTrue
:args[0]: () Defines the beamformer.
- Else
- Output:
() – Define the beam-formed signal.