Aiming at the problems that traditional algorithm of S-random interleaver can not guarantee the success of its search and has large time delay,an improved algorithm is put forward.Based on Logistic chaotic mapping,the improved algorithm has the capability of controllable randomness,which makes the algorithm get better balance between randomicity and certainty,and overcome the shortcomings of traditional algorithm.As shown in the simulation results,when the frame length is from 1 000 to 5 000,the time delay ...