Planning and Installation of CDMA- 2000 Basestations

• Main Authors: Yung-Neng Chang, 張詠能
• Other Authors: Jie - Cherng Liu
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/53517642369637235198

碩士 === 大同大學 === 通訊工程研究所 === 93 === Cellular planning is a complex process．For achieving the efficient cellular planning，it is necessary to understand the propagation characteristics of cellular systems．In this thesis，the objectives of base station planning is to offer voice service in 750,000 users and the data service in 150,000 users，while the coverage of signal up to 95% of Taiwan，i.e.，GOS（Grade of service）= 2%．By using the Okumura - HATA Propagation Model and with the aid of electronic map and Planet EV tool，we can predict the quantity of basestations，the transmission power，the antenna height，and etc． In the third generation of mobile communication system，at present， there are four W- CDMA and one CDMA- 2000 system operators in Taiwan．This thesis adopts the standard of CDMA- 2000 to plan the base station network，which adopts the frequency band of 800MHz and the cost of investment is relatively low and this system is relatively succeed at present．However，since CDMA is an interfering limited system，the system capacity and coverage will change with the strength of interference．Therefore the system operator has to evaluate the interference level at the band of the operating frequency before he gains the license．In this thesis，we calculate the weighting map by means of 2G、operator traffic distribution．Based on the traffic distribution and calculation of the Q factor，we can judge the basestation is balance or not at every sector． Because of Taiwan have high population density in small area，so the chance that GSM and CDMA base stations to be put together will be quite high，so it is very important to calculate the isolation criteria of GSM/ CDMA to prevent the interference between downlink of CDMA and uplink of GSM．Based on the criteria，the minimum separated distance of the two system antennas can be determined accordingly． Finally，it is also important to estimate the indoor coverage of the wireless communication system，Through the calculation of Link Budget and engineering experience，we can estimate the coverage and the corresponding cost，and thus the system operator can estimate how to use the possible least cost to achieve the possible maximum profit．