MC-CDMA

INTRODUCTION:
EVOLUTION OF WIRELESS SYSTEM:
The first generation (1G) mobile cellular systems provided analogue voice communication to mobile users using FDMA. The 2G wireless systems provided digital voice communications using TDMA and CDMA as multiple access techniques. The 3G mobile communication systems provide wide area coverage using Wideband Code Division Multiple Access (W-CDMA) as the multiple access technique. The 4G are intended to provide high speed, high capacity, low cost per bit, IP based services. MC-CDMA is the most promising multiple access technique for 4G cellular systems.

KEY PARAMETERS OF 3G AND 4G SYSTEMS
Parameters 3G 4G
Frequency band 1.8 to 2.5 GHz 2 to 8 GHz
Bandwidth 5 to 20 MHz 5 to MHz
Data rate Up to 2 mbps Up to 20 mbps
Access W-CDMA MC-CDMA
Switching Circuit / Packet Packet
Mobile top speeds 200 Kms/h 200 hms/h

MULTIPATH FADING CHANNEL:
The mobile or in...