Implemented Simulator

This commit is contained in:
Andreas Tsouchlos 2022-11-15 00:30:27 +01:00
parent 8f4b7e1fa1
commit c24a36db07

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@ -130,13 +130,11 @@ class Simulator:
target_frame_errors: int):
"""Construct and object of type simulator.
TODO: ...
:param n:
:param k:
:param decoders:
:param SNRs:
:param target_frame_errors:
:param n: Number of bits in a codeword
:param k: Number of bits in a dataword
:param decoders: Sequence of decoders to test
:param SNRs: Sequence of SNRs for which the BERs should be calculated
:param target_frame_errors: Number of frame errors after which to stop the simulation
"""
# Simulation parameters
@ -156,110 +154,93 @@ class Simulator:
self._curr_num_frame_errors = 0
self._curr_num_bit_errors = 0
self._curr_num_total_bits = 0
self._curr_num_iterations = 0
# Results
# Results & Miscellaneous
self._BERs = []
self._sim_running = False
self._BERs = [[]]
def _update_sim_state(self, bit_errors: int):
pass
def _simulate_transmission(self) -> int:
"""Simulate the transmission of a single codeword.
:return: Number of bit errors that occurred
"""
SNR = self._SNRs[self._current_SNRs_index]
decoder = self._decoders[self._current_decoder_index]
def _simulate_transmission(self, decoder: typing.Any, SNR: float) -> bool:
# Simulate channel
y = noise.add_awgn(self._x_bpsk, SNR, self._n, self._k)
# Decode received frame
x_hat = decoder.decode(y)
# Update statistics
bit_errors = count_bit_errors(self._x, x_hat)
self._curr_num_total_bits += self._x.size
return count_bit_errors(self._x, x_hat)
def _update_statistics(self, bit_errors: int) -> None:
"""Update the statistics of the simulator.
:param bit_errors: Number of bit errors that occurred during the last transmission
"""
self._curr_num_iterations += 1
if bit_errors > 0:
self._curr_num_frame_errors += 1
self._curr_num_total_bits += bit_errors
self._curr_num_bit_errors += bit_errors
return bit_errors > 0
def _advance_state(self) -> None:
"""Advance the state of the simulator.
def _simulate_SNR(self, SNR):
pbar = tqdm(total=self._target_frame_errors,
desc=f"Simulating for SNR = {SNR} dB", position=2, leave=False,
bar_format="{l_bar}{bar}| {n_fmt}/{total_fmt} [{elapsed}<{remaining}]")
This function also appends a new BER value to the self._BERs array
if the number of target frame errors has been reached
"""
if self._curr_num_frame_errors >= self._target_frame_errors:
# TODO: Properly handle the multiple decoders
self._BERs[self._current_decoder_index]\
.append(self._curr_num_bit_errors / (self._curr_num_iterations * self._n))
while self._curr_num_frame_errors < self._target_frame_errors:
error_occurred = self._simulate_transmission()
if error_occurred:
pbar.update(1)
pbar.close()
self._curr_num_frame_errors = 0
self._curr_num_bit_errors = 0
self._curr_num_iterations = 0
self._BERs.append(self._curr_num_bit_errors / self._curr_num_total_bits)
if self._current_SNRs_index < len(self._SNRs)-1:
self._current_SNRs_index += 1
else:
if self._current_decoder_index < len(self._decoders)-1:
self._current_decoder_index += 1
self._current_SNRs_index = 0
self._BERs.append([])
else:
self._sim_running = False
def
def start(self) -> None:
"""Start the simulation.
def test_decoder(self) -> typing.Tuple[np.array, np.array]:
"""Calculate the Bit Error Rate (BER) for a given decoder for a number of SNRs.
This is a blocking call. A call to the stop() function
from another thread will stop this function
"""
self._sim_running = True
This function assumes the all-zeros assumption holds. Progress is printed to stdout.
while self._sim_running:
bit_errors = self._simulate_transmission()
self._update_statistics(bit_errors)
self._advance_state()
def stop(self) -> None:
"""Stop the simulation."""
self._sim_running = False
@property
def SNRs_and_BERs(self) -> typing.Tuple[np.array, np.array]:
"""Get the current results.
If the simulation has not yet completed, the BERs which have not yet been calculated are set to 0.
:return: Tuple of numpy arrays of the form (SNRs, BERs)
"""
SNRs = np.array(self._SNRs)
decoder = self._decoders[self._current_decoder_index]
for SNR in tqdm(self._SNRs[self._current_SNRs_index:],
desc=f"Calculating BERs for {decoder.__class__.__name__}",
position=1, leave=False, bar_format="{l_bar}{bar}| {n_fmt}/{total_fmt}"):
pbar = tqdm(total=self._target_frame_errors,
desc=f"Simulating for SNR = {SNR} dB", position=2, leave=False,
bar_format="{l_bar}{bar}| {n_fmt}/{total_fmt} [{elapsed}<{remaining}]")
while self._curr_num_frame_errors < self._target_frame_errors:
error_occurred = self._simulate_transmission()
if error_occurred:
pbar.update(1)
pbar.close()
self._BERs.append(self._curr_num_bit_errors / self._curr_num_total_bits)
return np.array(self._SNRs), np.array(self._BERs)
def test_decoders(n: int,
k: int,
decoders: typing.List,
SNRs: typing.Sequence[float] = np.linspace(1, 7, 7),
target_frame_errors: int = 100) \
-> typing.Tuple[np.array, np.array]:
"""Calculate the Bit Error Rate (BER) for a number of given decoders for a number of SNRs.
This function assumes the all-zeros assumption holds. Progress is printed to stdout.
:param n: Length of a codeword of the used code
:param k: Length of a dataword of the used code
:param decoders: List of decoder objects to be tested
:param SNRs: List of SNRs for which the BER should be calculated
:param target_frame_errors: Number of frame errors after which to stop the simulation
:return: Tuple of the form (SNRs, [BERs_1, BERs_2, ...]) where SNR and BERs_x are numpy arrays
"""
result_BERs = []
start_time = default_timer()
for decoder in tqdm(decoders,
desc="Calculating the answer to life, the universe and everything",
position=0,
leave=False,
bar_format="{l_bar}{bar}| {n_fmt}/{total_fmt}"):
_, BERs = test_decoder(n, k, decoder, SNRs, target_frame_errors)
result_BERs.append(BERs)
end_time = default_timer()
print(f"Elapsed time: {end_time - start_time:.2f}s")
return SNRs, result_BERs
# TODO: Make sure the length of each BER_array is the same as the number of SNRs
BERs = [np.array(BER_array) for BER_array in self._BERs]
return SNRs, BERs
@dataclass
class SimulationParameters: