8.4 Spread spectrum communication systems Scramle 8.4.1 DSSS systems √Hide block diagram of a DSSS system is, U m(v0u① r(t) 8(T r≥0 0 t=T 0 cos 2nft c(t) I(t) c(t) cos 2nf PSK modulator T Channel- PSK demodulator What happen in SPECTUM? (0 sps(t) Tos(t) espread c(t) ()+J(t) UESTC-Wireless communicatons Prof李晓峰 12