Question

(b) for part b answer could you please tell me how s1 and s2 are calculated

6. Could you please explain how thetak is obtained ( inside the green marking )

3. Consider a CDMA system which allocates the spreading codes vi= {+1,+1,+1,+ 1l} and 1, 1, 1,1} to two users V2 (a) Show that vi and v2 are orthogonal. (b) Use the code vi and v2 to CDMA-modulate the data sequences dı= 01101 and d2 =11111 to generate si and s2 respectively 6. Assume T4-QPSK modulation with the following mapping dibit 11 00 01 10 phase inerement 3T 4 4 4 Suppose that the phase at the (n-1)th interval is -1-3/4 and that the information bit sequence from the nth to (n+4)th intervals is m-[1001010011]. Determine the IQ channel data stream (} (or {dz(k)}) and {Q} (or di(k)) for k=n to n+4 Qd,(k) A, sin e I d2 (k) A cos A-1 for QPSK interval dibit Phase phase 6 increment 2 и /4 10 7x /4 0 1 n -0.7071 n+1 01 3 /4 5 /4 -0.7071 0 n+2 01 1 0 3 /4 0.7071 n+3 00 я /4 к /4 0.7071 6 /4 n+4 11 5л /4 0 -1 (а) 4. -Zui(k)v2({) —(+1)x (+1)+(+1)х(-1)+(+1)x(-1)+ (+1)x (+1) —D0 = k1 (b) "0"->1 "1"->-1 di' 1-1-111 d2'-1,-1,-1,-1,-1 +111+1 - 1- 1-1 -1-1-1 - 1 - 1+1+1+1+1- 1 - 1- 1- 1} S1 К-1+1+1 — 1—1+1+1-1-1+1+1-1- 1 +1+1-1 —1+1+1— 1} S2

Answer 1

a) maя СыRг) -1 i mag) 1, 1,1, 1, 1 d2= о, 1, 1, о, 1 d 1,-1,-1,-1,- 1 1. -1,-1, 1, -1 1,1,1,1 -1,-1,-1,-1 , -1,-1,-1,-1 1,1,1,1, -1, -1,-1,-1 2 4,1,4-1 -1, 1,1,-1,-1,4,1,-1, -1, 1,1,-1 aiven, (n)" phase = phase o nh fntoryal - en-i ntotval phax t þhau inoumat phase in) - 4 4 Phose (nti) 21 3? 4 phase (nt2) n3 - 4 phase (nt3) = 6IT cs Scanned withphase (nt4) CamScanner 4