Performance Analysis and Spectrum Efficiency of Cellular Mobile Communication Systems

• Main Authors: Chang, Chien-Hsiung, 張建雄
• Other Authors: Chao, Chi-Chao
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/58829393149802946650

碩士 === 國立清華大學 === 電機工程研究所 === 82 === Spectrum efficiency is of vital importance in designing cellular mobile communication systems since bandwidth is a very limited resource. Hence how to effectively use the available bandwidth is a challenging task. The method of fixed channel assignment (FCA) have been widely adopted in current mobile phone systems. In this thesis, performance analysis of cellular systems employ- ing FCA is first studied. Two priority schemes for handoff calls are considered: one is adding queue and the other is reserving a fixed number of channels. Results obtained show that if priori- ty schemes exist for handoff calls, the forced termination proba- bility will be much lower than he new call blocking probability. Sectorization has been well-known for reducing the number of co- channel cells. Our analysis on spectrum efficiency based on diff- erent constraints on the new calls blocking and forced terminati- on probability, show that, however, if not properly designed, the sectored system might be worse than the system without sectori- zation. Finally, the performance of systems using the optimum DCA method, the ``maximumm packing''(MP) strategy, is analyzed by computer simulation. Again higher priority for handoff calls is considered. Results obtained show that tthe new call blocking probability and forced termination probability of systems using the MP strategy will be smaller than those of systems employing the FCA method under most all of the interesting new call arrival rates.