How to make this loop fast.

I want to optimised the below given code,

   for I=1:1*10^5
                     y1=Mod_sig*h(1,I)*Theta(1,I);
                     rx=y1+1*Noise(no_of_points, Nsp,Gain_edfa,h_p,Nu,B);
                     clear y1
                     rx_fft=fftshift(fft(rx));
                     clear rx
                     obpf_opfd=OBPF.*rx_fft;
                     clear rx_fft
                     Obpf_optd=ifft(ifftshift(obpf_opfd));
                     clear obpf_opfd
                     De_mod=Delay_demodulation(Obpf_optd,samples_per_bit);
                     clear Obpf_optd
                     Elpf_op= lowpass_bessel_filter_output(order,cutoff_frequency,De_mod,Fs);
                     clear De_mod
                     Samp_sel=Elpf_op(:,4:samples_per_bit:end);
                     clear Elpf_op
                     Th_op=Samp_sel>0;
                     error=sum(sum(data1~=Th_op)); 
                     Err=[Err error];                
                end 
its taking a lot of time.

Answer 1

[madhan ravi]

Remove all clear commands from the loop and see

[Abhishek mani shukla]

thanks for your suggestion but its not working.