8.4 Spread spectrum communication systems √Scramle 8.4.1 DSSS systems block diagram of a DSSS system is, nm m(v0u① 8r(T-t) r20 0 t=T a cos 2nft c(t) I (t c(t) c0s2对ft PSK modulator Channel- PSK demodulator What happen in SPECTUM? (0 sps(t) bs(0) Despread c(t) n(0+J() UESTC-Wireless communicatons Prof李晓峰 11