The effect of higher receiver sensitivity on the coverage of a spread spectrum CDMA system

We examine the effect of higher receiver sensitivity on coverage of a code division multiple access (CDMA) cellular system. The reduced system noise figure of a base station is achieved by placing low noise amplifier (LNA) between receive antenna and base station radio. Using noise figure theory, we develop an analytical model of sensitivity improvement which is a function of reverse-link noise rise and antenna noise temperature. Since CDMA has reverse power control, sensitivity improvement is manifested in the reduction of mobile transmit power. Field experiments are performed and data collected to test the model. The positive result shows that LNA can be used to reduce mobile transmit power and their loading on adjacent cells.