Simulate multiple SNRs

docs/general_idea.md

@@ -102,7 +102,7 @@ parity constraint. In a similar vein, we can define the following set of
 polynomial equations to describe codewords:
 
 $$
-F = \left[\begin{array}{c}1 - x_1^2 \\ \vdots\\ 1 - x_n^2 \\ 1 - \prod_{i \in A(1)}x_i \\ \vdots\\ 1 - \prod_{i \in A(m)}x_i\end{array}\right] \overset{!}{=} \bm{0}.
+F(\bm{x}) = \left[\begin{array}{c}1 - x_1^2 \\ \vdots\\ 1 - x_n^2 \\ 1 - \prod_{i \in A(1)}x_i \\ \vdots\\ 1 - \prod_{i \in A(m)}x_i\end{array}\right] \overset{!}{=} \bm{0}.
 $$
 
 This is a problem we can solve using homotopy continuation.

python/examples/simulate_error_rate.py

@@ -4,6 +4,7 @@ import galois
 import argparse
 from dataclasses import dataclass
 from tqdm import tqdm
+import pandas as pd
 
 # autopep8: off
 import sys
@@ -47,7 +48,7 @@ def decode(tracker, y, H, args: SimulationArgs) -> np.ndarray:
     return x_hat
 
 
-def simulate_error_rates_for_SNR(H, Eb_N0, args: SimulationArgs) -> typing.Tuple[np.ndarray, np.ndarray, np.ndarray]:
+def simulate_error_rates_for_SNR(H, Eb_N0, args: SimulationArgs) -> typing.Tuple[float, float, float, int]:
     GF = galois.GF(2)
     H_GF = GF(H)
     G = H_GF.null_space()
@@ -84,14 +85,29 @@ def simulate_error_rates_for_SNR(H, Eb_N0, args: SimulationArgs) -> typing.Tuple
 
         num_frames += 1
 
-        if frame_errors > args.target_frame_errors:
+        if frame_errors >= args.target_frame_errors:
             break
 
     BER = bit_errors / (num_frames * n)
     FER = frame_errors / num_frames
     DFR = decoding_failures / num_frames
 
-    return FER, BER, DFR
+    return FER, BER, DFR, frame_errors
+
+
+def simulate_error_rates(H, Eb_N0_list, args: SimulationArgs) -> typing.Tuple[np.ndarray, np.ndarray, np.ndarray, np.ndarray]:
+    FERs = []
+    BERs = []
+    DFRs = []
+    frame_errors_list = []
+    for SNR in Eb_N0_list:
+        FER, BER, DFR, num_frames = simulate_error_rates_for_SNR(H, SNR, args)
+        FERs.append(FER)
+        BERs.append(BER)
+        DFRs.append(DFR)
+        frame_errors_list.append(num_frames)
+
+    return np.array(FERs), np.array(BERs), np.array(DFRs), np.array(frame_errors_list)
 
 
 def main():
@@ -101,9 +117,10 @@ def main():
 
     parser.add_argument("-c", "--code", type=str, required=True,
                         help="Path to the alist file containing the parity check matrix of the code")
-    # TODO: Extend this script to multiple SRNs
+    parser.add_argument("--snr", type=float, required=True, nargs=3,
-    parser.add_argument("--snr", type=float, required=True,
+                        metavar=('start', 'stop', 'step'),
-                        help="Eb/N0 to use for this simulation")
+                        help="SNRs to simulate (Eb/N0) in dB")
+
     parser.add_argument("--max-frames", type=int, default=int(1e6),
                         help="Maximum number of frames to simulate")
     parser.add_argument("--target-frame-errors", type=int, default=200,
@@ -139,12 +156,12 @@ def main():
         max_frames=args.max_frames,
         target_frame_errors=args.target_frame_errors)
 
-    FER, BER, DFR = simulate_error_rates_for_SNR(H, args.snr, simulation_args)
+    SNRs = np.arange(args.snr[0], args.snr[1], args.snr[2])
-
+    FERs, BERs, DFRs, frame_errors_list = simulate_error_rates(
-    print(f"FER: {FER}")
+        H, SNRs, simulation_args)
-    print(f"DFR: {DFR}")
-    print(f"BER: {BER}")
 
+    df = pd.DataFrame({"SNR": SNRs, "FER": FERs, "BER": BERs, "DFR": DFRs, "frame_errors": frame_errors_list})
+    print(df)
 
 if __name__ == "__main__":
     main()