  Underdetermined Blind Source Separation(UBSS) is an important issue, for
sparse signals, a novel two-step approach for UBSS based on the law of large
numbers and minimum intersection angle rule (LM method) is presented. In the
first step, the estimation of the mixed matrix is obtained by using the law of
large numbers, and the number of source signals is displayed graphically. In
the second step, the method of estimating the source signal with the minimum
intersection angle rule is proposed. Finally, two simulation results that
illustrate the effectiveness of the theoretical results are presented. It has
simple principle and good transplantation capability and can be widely applied
in various fields of digital signal processing.
