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//
// interleaver_example.c
//
// This example demonstrates the functionality of the liquid
// interleaver object. Interleavers serve to distribute
// grouped bit errors evenly throughout a block of data. This
// aids certain forward error-correction codes in correcting
// bit errors. In this example, data bits are interleaved and
// de-interleaved; the resulting sequence is validated to
// match the original.
// SEE ALSO: packetizer_example.c
//
#include <stdio.h>
#include <stdlib.h> // for rand()
#include "liquid.h"
int main() {
// options
unsigned int n=9; // message length
// create the interleaver
interleaver q = interleaver_create(n);
interleaver_set_depth(q, 4);
interleaver_print(q);
// create arrays
unsigned char x[n]; // original message data
unsigned char y[n]; // interleaved data
unsigned char z[n]; // de-interleaved data
// generate random data sequence
unsigned int i;
for (i=0; i<n; i++)
x[i] = rand()%256;
// interleave/de-interleave the data
interleaver_encode(q,x,y);
interleaver_decode(q,y,z);
//interleaver_print(q);
// print, compute errors
unsigned int num_errors=0;
printf("%6s %6s %6s\n", "x", "y", "z");
for (i=0; i<n; i++) {
printf("%6u %6u %6u\n", x[i], y[i], z[i]);
//printf("y[%u] = %u\n", i, (unsigned int) (y[i]));
//printf("y[%u] = %#0x\n", i, (unsigned int) (y[i]));
num_errors += (x[i]==z[i]) ? 0 : 1;
}
printf("errors: %u / %u\n", num_errors, n);
// destroy the interleaver object
interleaver_destroy(q);
printf("done.\n");
return 0;
}
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