Given the serial data sequence

101011 010010 100110 110011

associate every other bit with the upper and lower data streams of the block diagrams of Figures 10.2 and 10.4. Draw on the same time scale (one below the other) the quadrature wave forms for the following data modulation schemes: QPSK, OQPSK, MSK type I, and MSK type II.

Figure 10.2

Figure 10.4

Integrate and sample cos wf V; ==}AT, AT, + N1 }Ad (1) Parallel to Ad (t) y(t) = x.(t) + n(t) serial conversion 90 V; = =} AT, + N2 sin @t Integrate and sample d (t) = (1, 1, 1, 1, . . .); symbol duration = 27, s cos (t/2Tp) cos (2nf1) sin (2ft) Serial/ d(t) = (1, 1, 1, 1, 1, 1, 1, 1, . . ) - (Bit duration = T, s) x(t) parallel converter sin (xt/2T,) dz(1) = (1, 1, 1, 1, ...); symbol duration = 2T,s (Staggered T,s relative to d,(t)) (a) t = (2k + 1)T, (2k + 1)T, Odt (2k 1)T, +1 d (1). Lowpass filter -1 x(t) cos (27ft) cos (/2T, ) sin (27ft) sin (t/2T,) t = 2(k + 1)T, - 2(k + 1)7, +1 dz(1) Lowpass filter )dt 2k Tp (b)