ex-ldpcvar-5000a

剑桥大学David J.C. MacKay 个人网站公布的2006年的代码

#!/bin/sh

# Example of a (10000,5000) LDPC code with varying numbers of check per bit,
# tested on Additive White Gaussian Noise channels with noise standard 
# deviations varying from 0.80 to 0.95.  The code has 20% columns with two 
# check bits, 70% columns with three check bits, and 10% columns with seven
# check bits.
#
# Testing is done by transmitting random messages, with pipes used so that
# intermediate files are avoided.  Decoding is done using a maximum of 250
# iterations of probability propagation.

set -e  # Stop if an error occurs
set -v  # Echo commands as they are read

make-ldpc ex-ldpcvar-5000a.pchk 5000 10000 2 evenboth 2x2/7x3/1x7 no4cycle
make-gen  ex-ldpcvar-5000a.pchk ex-ldpcvar-5000a.gen dense
rand-src  ex-ldpcvar-5000a.src 1 5000x100

# NOISE STANDARD DEVIATION 0.80, Eb/N0 = 1.94 dB

encode      ex-ldpcvar-5000a.pchk ex-ldpcvar-5000a.gen ex-ldpcvar-5000a.src - \
 | transmit - - 1 awgn 0.80 \
 | decode   ex-ldpcvar-5000a.pchk - - awgn 0.80 prprp 250 \
 | verify   ex-ldpcvar-5000a.pchk - ex-ldpcvar-5000a.gen ex-ldpcvar-5000a.src

# NOISE STANDARD DEVIATION 0.85, Eb/N0 = 1.41 dB

encode      ex-ldpcvar-5000a.pchk ex-ldpcvar-5000a.gen ex-ldpcvar-5000a.src - \
 | transmit - - 1 awgn 0.85 \
 | decode   ex-ldpcvar-5000a.pchk - - awgn 0.85 prprp 250 \
 | verify   ex-ldpcvar-5000a.pchk - ex-ldpcvar-5000a.gen ex-ldpcvar-5000a.src

# NOISE STANDARD DEVIATION 0.90, Eb/N0 = 0.92 dB

encode      ex-ldpcvar-5000a.pchk ex-ldpcvar-5000a.gen ex-ldpcvar-5000a.src - \
 | transmit - - 1 awgn 0.90 \
 | decode   ex-ldpcvar-5000a.pchk - - awgn 0.90 prprp 250 \
 | verify   ex-ldpcvar-5000a.pchk - ex-ldpcvar-5000a.gen ex-ldpcvar-5000a.src

# NOISE STANDARD DEVIATION 0.95, Eb/N0 = 0.45 dB

encode      ex-ldpcvar-5000a.pchk ex-ldpcvar-5000a.gen ex-ldpcvar-5000a.src - \
 | transmit - - 1 awgn 0.95 \
 | decode   ex-ldpcvar-5000a.pchk - - awgn 0.95 prprp 250 \
 | verify   ex-ldpcvar-5000a.pchk - ex-ldpcvar-5000a.gen ex-ldpcvar-5000a.src