Assume there are 3 users in CDMA network and each users are using their own code for the communication. User As code is 1 -1 -1 1 1 -1 -1 1, Bs code is 1 -1 1 -1 -1 1 -1 1 and Cs code is 1 -1 -1 1 -1 1 1 -1.

1. Check if all pairs of codes are orthogonal each other. (5 points)

2. Find the encoded bit stream for each user when user A transmits 0, B transmits 1`, and C transmits 1. And what is the composite signal of three users? (5 points)

Composite signal has been transmitted from Base station and user B is receiving signal and decode it. Show decoding process of user B