lanx@ubuntu14-large:~$ perlbrew use perl-5.28.0
lanx@ubuntu14-large:~$ perl 
use warnings;
use strict;
use Encode qw/decode/;
use Data::Dump qw/dd/;


dd decode('UTF-16-BE', "\x3D\xDD\xFA", Encode::FB_CROAK|Encode::LEAVE_SRC );
dd decode('UTF-16-BE', "\xFA",         Encode::FB_CROAK|Encode::LEAVE_SRC );

dd decode('UTF-16-LE', "\xD8\xFA\xDD", Encode::FB_CROAK|Encode::LEAVE_SRC );
dd decode('UTF-16-LE', "\xDD",         Encode::FB_CROAK|Encode::LEAVE_SRC);

__END__
"\x{3DDD}"
""
"\x{FAD8}"
""
lanx@ubuntu14-large:~$ perl -v

This is perl 5, version 28, subversion 0 (v5.28.0) built for x86_64-linux