Application of Information Theory to the Design of 4th Generation Cellular Communication Systems

摘要

The design of 4th Generation Cellular Communication Systems will face many challenges, including the need to achieve very high spectrum efficiency when compared to 3rd Generation cellular systems. In this paper, we investigate the fundamental limits of DSSS-CDMA versus TDMA for achieving high spectrum efficiency by presenting the capacity regions for each including the effects of multiple transmit and receive antennas. To assess the channel capacity region for local area and wide area coverage, a channel model based upon uncorrelated Rayleigh fading and model with a strong spatial correlation and Ricean component are evaluated. For multiple transmit and receive antennas, both open loop and closed loop capacity regions are assessed, where the closed loop capacity assumes channel state information at the transmitter and optimum power allocation. Conclusions from the work include an assessment of what approaches hold the best promise for achieving high spectrum efficiency for future cellular communication systems.