Research On Key Radio Network Technologies In Distributed Antenna Cellular System

OFDM (Orthogonal frequency division multiplexing) technology has been proposed for one of the air interface standards for the next generation wireless communication systems due to its capability in combating frequency selective fading and inter-symbol interference. Furthermore, Distributed Antennas Cell System (DACS) becomes one of the candidates for B3G system because of high capacity and high user's SIR (Signal Interference Ratio).This dissertation focuses on studying and analyzing the key radio network technologies of DACS based on OFDM.Chapter 1 reviews the development history of wireless system and some recent researches on distributed antenna system. Furthermore, make an overall description of DACS.Chapter 2 proposes several subcarrier assignment algorithms for the light load or moderate load and several subcarrier assignment algorithms in high load from the view of fairness. Analyzes and compares the performance of those algorithms. We give the best choice under different conditions in DACSChapter 3 propose a new RP (Reuse Partitioning) scheme based on the SDMA (Spatial Division Multi-Access). Analyzes and compare the capacity of two schemes. Simulation shows that the capacity of proposed RP scheme is higher than the traditional RP scheme.Chapter 4 studies the existent shortcoming of traditional RP scheme; then we propose the concept of "interference coordination period" between the cells. Based on this concept a new frequency and time interference coordination scheme has been proposed for improve the user's rate in the edge of the cell. Simulation shows the propose scheme is better than the traditional scheme.Finally, the dissertation is summarized, and some ideas about future research on radio network technologies of DACS based on OFDM are put forward.