A new sub-array asynchronous recursive least square algorithm (SARLS) is pr
oposed. The number of elements of the smallest sub-array can be less than t
he number of interferers. The computational load of SARLS can be reduced to
o(N) while similar array performance to that of RLS is obtained. When the
sub-array size is small, SARLS will converge Faster than the conventional R
LS.