sentence: As shown in Figure 10 , the results can be summarized as follows : ( a ) the output C / N performance of the STPAP algorithm in [ 30 ] is always the best one , while the output C / N performance of the STPAP algorithm in [ 29 ] is worse than the other three criteria ; ( c ) the output C / N performance of the proposed STPAP algorithm is a little better than the existing STPAP algorithm in [ 31 ] .