| Computer simulations have been used to study the effect of narrow switched-beam transmission and power control at the base station on the interference characteristics and traffic capacity of digital cellular (IS-136) systems. In simulations, four narrow beams in place of a sectored antenna pattern are used, and a power control mode with up to 30 watts maximum transmitted power is applied. Results indicate that with transmission on four narrow beams at the base station, the improvement in carrier to interference ratio (C/I) is more than 4 dB. Furthermore, with narrow beam transmission and the base station power control, the total improvement in C/I is 8 to 10 dB. If this C/I gain is utilized to maximize the amount of served traffic, the system capacity can be enhanced by more than 100%. Therefore, improvements in system performance with increased capacity and improved quality are expected by incorporating narrow beam transmission and base station power control. |
