ode Division Multiple Access $($CDMA$)$ and Carrier Sense Multiple Access $/$ Collision

Detection $($CSMA$/$CD$)$ provide two mechanisms for medium access control.

i$)$ Assume that CDMA is used in a network with three mobile stations $2,3$ and $4,$ and a base station, station $1.$ The three mobile stations intend to send the following bit sequences $110,001$ and $101$ respectively; the base station is silent. A $0$ is encoded as $-1,$ a $1$ is encoded as $+1$ and silence is represented by $0.$ Give the signals that the base

station will receive and discuss how the base station will decode these signals.

The chip sequences of the stations are as follows: