that is the useful code to sove the example

PSK系统半解析仿真 matlab符号间干扰ISI与误码率的关系 与Eb/No的对应关系-Correspondence between PSK system semi-analytical simulation matlab inter-symbol interference ISI and BER with Eb/No

function [out1,out2] = humps(x) HUMPS A function used by QUADDEMO, ZERODEMO and FPLOTDEMO. Y = HUMPS(X) is a function with strong maxima near x = .3 and x = .9. [X,Y] = HUMPS(X) also returns X. With no input arguments, HUMPS uses X