function h=channel(Nth_cm,Th,Ts)
                     %信道沖激響應間隔
    h0=UWB_SV_channel(2,4,Th);            %信道沖激響應
    h1=h0(:,2);
    h=n_upsample(h1,Th,Ts);
    %＝＝＝＝＝＝＝＝＝＝＝＝＝