jist.swans.radio
Class BERTable

java.lang.Object
  jist.swans.radio.BERTable

public class BERTable
extends java.lang.Object

Implementation of Bit-Error-Rate calculations (via a loaded table) for a range of Signal-to-Noise-Ratio values.

Since:

SWANS1.0

Version:

$Id: BERTable.java,v 1.9 2005/03/13 16:11:55 barr Exp $

Author:

Rimon Barr <barr+jist@cs.cornell.edu>

Field Summary

private double[]	ber Table with Bit-Error-Rate values for given Signal-to-Noise-Ratio values.
private double[]	snr Table with Bit-Error-Rate values for given Signal-to-Noise-Ratio values.

Constructor Summary

BERTable(java.lang.String filename)
Initialize the BER table with data from given file.

Method Summary

double	calc(double snrVal) Compute BER value by interpolating among existing SNR points.
private void	check() Verify the input data.
private void	load(java.io.File f) Load BER data from a given file.
boolean	shouldDrop(double snrVal, int bits) Compute probabilistically whether an error occured for a given number of bits and SNR value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

snr

private double[] snr

Table with Bit-Error-Rate values for given Signal-to-Noise-Ratio values.

ber

private double[] ber

Table with Bit-Error-Rate values for given Signal-to-Noise-Ratio values.

Constructor Detail

BERTable

public BERTable(java.lang.String filename)
         throws java.io.IOException

Initialize the BER table with data from given file.

Parameters:

filename - file to load

Throws:

java.io.IOException - unable to read BER file

Method Detail

load

private void load(java.io.File f)
           throws java.io.IOException

Load BER data from a given file. BER data should be formatted as a plain text file with floating point numbers in two columns (SNR BER). The SNR values should be ascending.

Parameters:

f - BER data file

Throws:

java.io.IOException - unable to read BER file

check

private void check()

Verify the input data. Check that SNR values were in ascending order.

calc

public double calc(double snrVal)

Compute BER value by interpolating among existing SNR points.

Parameters:

snrVal - input SNR value for BER computation (interpolation)

Returns:

Bit-Error-Rate

shouldDrop

public boolean shouldDrop(double snrVal,
                          int bits)

Compute probabilistically whether an error occured for a given number of bits and SNR value.

Parameters:

snrVal - Signal-to-Noise-Ratio value

bits - number of bits

Returns:

whether (probabilistically) an error occurred