Network Planning For CDMA Cellular Communication System

Code Division Multiple Access (CDMA) has rapidly become a leading technology for commercial Cellular systems because it has large capacity, good voice quality and big potential of upgrading etc. In 1996, China began the commercial trial of CDMA cellular communication network in four cities, Beijing, Shanghai, Guangzhou and Xi'an. At present, China Unicom begins to construct 800MHz CDMA cellular communication network in a large scale in China. So it is necessary for us to research the design of network planning for CDMA cellular communication system.The paper introduces the structure of CDMA network, synchronization request and transmission model, on the basis of which, the paper makes the CDMA. (IS-95A) network planning for the urban area of a small city. It evaluates the number of BS (Base Station) from two aspects, satisfying the request of capacity and satisfying the request of coverage. The criteria comply with The Technology System of China Unicom 800 MHz CDMA Digital Cellular Communication Network. We may add a certain BSs on the basis of the evaluated BS number to cover all the urban area without any blank. After confirming the number of BS, we set the number of voice channels and the number of cells according to the relation between capacity and coverage area' radius of the CDMA cell with a certain I/C value. Because CDMA has the characteristic of soft capacity, the paper presents that we may set different I/C values for the system in different time and make the dynamic distribution for the number of channels according to the situation of voice traffic to satisfy the voice request of the users furthest. Power control is one of CDMA key technologies. It can add the capacity if we use effective way of power control. The paper presents a kind of power control algorithm, which is relative to the distance that mobile station is away from the base station (BS). It may greatly save the transmission power of the BS.