Ryan Malloy
66f20af368
Rename python/ to src/ following PEP 517/518 modern packaging conventions. Also adds .gitignore for docs and build artifacts.
46 lines
1.1 KiB
Python
46 lines
1.1 KiB
Python
#!/usr/bin/env python3
|
|
# -*- coding: utf-8 -*-
|
|
# MIT License
|
|
# Copyright (c) 2018 zleffke
|
|
# Ported to GNU Radio 3.10+ by gr-mcp
|
|
|
|
"""
|
|
Biphase-L Decoder for Cospas-Sarsat 406 MHz beacons.
|
|
|
|
Biphase-L (Manchester) encoding represents:
|
|
- Bit 0: Low-to-High transition at bit center
|
|
- Bit 1: High-to-Low transition at bit center
|
|
|
|
This decoder extracts the data bit from each symbol pair.
|
|
"""
|
|
|
|
import numpy as np
|
|
from gnuradio import gr
|
|
|
|
|
|
class biphase_l_decode_bb(gr.decim_block):
|
|
"""
|
|
Biphase-L Decoder.
|
|
|
|
Input: Unpacked byte stream of Biphase-L encoded symbols (2 samples per bit).
|
|
Output: Unpacked byte stream of decoded bits.
|
|
|
|
Decimation factor: 2 (two input samples produce one output bit)
|
|
"""
|
|
|
|
def __init__(self):
|
|
gr.decim_block.__init__(
|
|
self,
|
|
name="biphase_l_decode_bb",
|
|
in_sig=[np.int8],
|
|
out_sig=[np.int8],
|
|
decim=2,
|
|
)
|
|
|
|
def work(self, input_items, output_items):
|
|
in0 = input_items[0]
|
|
out = output_items[0]
|
|
# Extract first sample of each symbol pair (the data bit value)
|
|
out[:] = in0[::2]
|
|
return len(output_items[0])
|