There are two files in the zip folder. bpsk_spread.m and jakesmodel.m
Steps for simulation:
1] Run jakesmodel.m first
2] Then run bpsk_spread.m .
3] Note that during the first run bpsk_spread.m has no rayleigh fading.This is because the corresponding code has been commented
4] The resulting performance is stored in BER_awgn.
5] Now uncomment the Rayleigh Fading code in bpsk_spread.m file.
6] Same time comment BER_awgn (line 112) and uncomment BER_ray variable.
7] Run the simulation.

To compare the perfromances of the receiver using DSSS plot the BER_awgn and BER_ray

>>semilogy([1:8],BER_awgn(1:8),'g*');
 hold on;
 semilogy([1:8],BER_ray(1:8),'-.b*');
 hold on;
 grid on;