4. Suppose two users in a Direct Sequence-CDMA system have signatures (that is, sequences of chips) given by (1 -1 1-1) and (1 1-1-1), respectively. (2) Evaluate the correlation between the two signatures. (b) Sketch the baseband signals for the two users when user 1 sends the bits 011, and user 2 sends the bits 101. Add the signals for the first bit only, and show that the output of the correlator for user 1 is -4, and the output of the correlator for user 2 is 4. Note that if the output of the correlator is negative, then the detected bit is a 0, and if the output is positive, the detected bit is a 1