资料介绍
lecture1_04>:
Lecture 1, Sept. 17, 2004
J 1. 8X{H 2. y 3. y8¤>óE 4. 8ê>X 5. XVg (a) S!SXC!CX (b) S¨A (c) D(Xê (d) (
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The Convergence of Wireless Systems
Wireless LAN (mobile computing) Semi-portable, high data rate IEEE 802.11b (1999) 11 Mbps, 2.4 GHz IEEE 802.11a (1999) 22-54 Mbps, 5.15 GHz IEEE 802.11g (2003) 20-54 Mbps, 2.4 GHz Mobile Telephony (cellular phone) Portable, low data rate European GSM (digital cellular) 8-12 Kbps, 900 MHz IS-95 Qualcomm CDMA GSM GPRS (2.5G) WCDMA (3G) 3.84 Mbps (384 Kbps-2 Mbps), 2 GHz
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UWB, IEEE 802.15.3, 3.1-10.6 GHz CDMA 2000 GPS: 1227.60 MHz 1575.42 MHz
Shannon’s
What it is? bandwidth
k'8ED4information rate¤° ¤' X 8 ê n 8 N n Channel Capacity Theorem, Claude Shannon, 1948¤ 8°8D'§(pD
&En
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§C in b/s, B in hertz"
C = B [log2(S