How does MATLAB code square wave fiter?

%Transmitted signal is iidx

iidx = zeros(N0,1); % N0 is the number of code.

iidx = transpose(round(rand(1,N0))*2-1); %iidx of i.i.d.(independent and identically distributed)

Tk=(rand(1,k)*MaxDelay); %Tk is delay, MaxDelay is Maximum delay of Tk.

Tk=sort(Tk);

Ck=randn(1,k); % Ck is the value of Channel Impulse Response

%Raised Cosine filtering case: Raisd Cosine fitering Channel is hRCf.

Beta = 0.22; % Roll-off factor for the Raised Cosine filter.

ndashi = -10*Tc:Tc/J:(10*Tc+Tc/J*(L-1)); %ndashi is Time vector (sampling intervals, Tc = 1, J =1, L is delay.

Rck=zeros(0,length(ndashi));

for k = 1:K, % k is number of paths, K is maximum number of path.

      ndashi = -10*Tc:Tc/J:(10*Tc+Tc/J*(L-1)); 

      t = ndashi - Tk(k); % delay between 0 and 1
      t = t+1e-10; %the denominator would be zero at t=0 (or manually set “Rcone(t=0)=1”)

      Rcone = (sin(pi*t/T)./(pi*t/T)).*(cos(Beta*pi*t/T)./(1-(2*Beta*t/T).^2)); %Raised Cosine filter

      Rck = [Rck; Rcone]; % Raised-Cosine FIR filter

      end

        hRCf = Ck * Rck; %

Now, I want to change Raised cosine fiter to square wave fiter?

How can I make the square wave fiter such as sampling intervals of Raised Cosine fiter?