Problem $4-$ Code Division Multiple Access $($CDMA$)(30$ points$)$

a$)$ Perform CDMA encoding and decoding for the following data $(d_0=-1$ and $d_1=1)$ and chipping code sequences $(1,1,1,-1,1,-1,-1,-1)$ and $(1,1,1,-1,1,-1,-1,-1)$ respectively.

$D_i=\frac{{\displaystyle \underset{m=\text{u}\text{a}\text{r}\text{r}}{\overset{M}{}}}{c}_m}{M}$