Communications Toolbox

Comparison of Symbol Error Rate and Bit Error Rate

In the example above, the symbol errors and bit errors are the same because each symbol is a bit. The commands below illustrate the difference between symbol errors and bit errors in other situations.

a = [1 2 3]'; b = [1 4 4]';
format rat % Display fractions instead of decimals.
[snum,srate] = symerr(a,b)
[bnum,brate] = biterr(a,b)

The output is below.

snum =

      2      


srate =

     2/3     


bnum =

      5      


brate =

     5/9  

bnum is 5 because the second entries differ in two bits and the third entries differ in three bits. brate is 5/9 because the total number of bits is nine. The total number of bits is, by definition, the number of entries in a or b times the maximum number of bits among all entries of a and b.

Example: Computing Error Rates

Performance Results via the Semianalytic Technique

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