3 senders A,B,C are transmitting data over a common channel using CDMA with 4-bit chipping sequences

Sender Data Chipping Sequence

A (0,1,0,1) ( 1 1 1 1 )

B (1,0,0,1) ( 1 1 -1 -1 )

C (1,1,1,0) ( 1 - 1 1 -1 )

(i) Prove that the codes are all orthogonal to each other

(ii) Work out the 16 bit encoded sequence transmitted by each sender

(iii) What is the 16 bit aggregate signal detected by any receiver assuming equal signal strengths?

(iv) Show how a receiver who shares the B's chipping sequence recovers the data transmitted by B from

the aggregate signal