Question 5 [20] a) Given the messages of user A and B are "101" and 011 respectively, i.e., User A's message: "101" and User B's message: "011. The two messages will be transmitted by using CDMA technique. Given two unique pseudo- random codes with chip rate of 4, PNA= "1010 and PNB =0110. i. ii. find the encoded message of A and B in BOTH binary value and voltage level format (show all encoding steps with labelled voltage level diagrams), [6] prove that the two pseudo-random codes, PNA and PNB are orthogonal, and [4] find the combined encoded signal in voltage level format with a labelled diagram. [4] iii. b) If the combined encoded signal of another CDMA decoding system with chip rate of 4 is received as shown below and the two decoded binary messages are I and O respectively. Voltage level 2 2 Determine ALL possible pseudo-random codes, PNA and PNB used in encoding the above combined encoded signal. [6] - End of ETA