 
Summary: The Rate/Performance Tradeos of Focused
Error Control Codes
Tom Fuja and Fady Alajaji
Department of Electrical Engineering
Systems Research Center
University of Maryland
College Park, MD 20742
Let B be a set of nonzero elements of F q
(q > 2); we say a code is
(t 1
; t 2
)focused on B if it can correct up to t 1
+ t 2
errors provided at most
t 1
of those errors lie outside B. The strategy is to oer dierent levels of
protection against \common" errors { those in B { and \uncommon" errors.
(The motivating example: correction of singlebitperbyte errors with codes
over F 2 b .)
This talk will compare the performance and rates of (t 1 ; t 2 )focused codes
