【作者】 周凯捷；

【导师】 张英海； 王卫东；

【作者基本信息】 北京邮电大学 ， 微电子学与固体电子学， 2008， 硕士

【摘要】 随着通信系统的不断发展,高速数据业务在未来移动通信系统中占有越来越大的比重,高速数据业务具有上下行传输速率不对称的显著特点。不仅如此,随着数据传输速率的提高,所需的发射功率也相应提高,对人类和环境的影响也越来越大。本文的研究表明:在电磁辐射限制下,上下行传输率也明显的非对称特性,上行链路的传输速率是受限的,而下行链路的传输速率远远大于上行链路。为了适应未来移动通信中的非对称传输特性,本文首先分析了时分双工技术支持非对称传输时存在的问题。时分双工技术可以通过可以根据业务的情况动态的调整上下行时隙的分配,从而灵活的为上下行分配资源,但同时会带来交叉时隙干扰的问题。区别于目前分析的比较透彻的TDD＼CDMA系统交叉时隙干扰问题,本文分析了存在同步误差时,TDD＼OFDMA系统交叉时隙干扰问题并提出了基于隔离区域的解决方案,该方案可以较好的控制交叉时隙用户的干扰,降低同步误差对系统性能的影响。论文第四章研究了支持非对称传输的频分双工技术。提出了非对称频分双工AFDD(Asymmetric Frequency Division Duplex)技术的概念:AFDD系统根据业务的实际情况确定上行(下行)单位带宽,将上行(下行)频率按上行(下行)单位带宽分成多个频点,所有上行(下行)频点组成上行(下行)频率池,每个小区根据业务的实际情况,动态使用频率池中的频点。并分析了基于AFDD技术的CDMA系统和OFDMA系统性能,结果表明:AFDD技术可以有效的提高系统容量,节省频率资源。更多还原

【Abstract】 With the development of communication system, the high date rate traffic plays more and more important part in future communication system, the high date rate traffic is characterized by the uplink rate is asymmetric to downlink rate. Furthermore, with increase of transmission rate, the power is also enhanced and the impact on human and environment is growing. By calculation it shows that: under the restriction of electromagnetic radiation, the uplink transmission rate is limited; the downlink rate is much higher than that of uplink.To adapt to the asymmetric characteristic of future communication system, the problem of TDD (time division duplex) technology when supporting asymmetric transmission is analyzed in this article. TDD can allocate the slot of uplink and downlink dynamically according to traffic conditions, but it introduces the problem of crossed timeslot interference. Different from the. topic of the crossed timeslot interference in TDD\CDMA system which was well analyzed, the disadvantage of crossed timeslot interference in TDD\OFDMA system is analyzed in this article. And the scheme based on isolated area is put forward to solve this problem which can control the interference of the crossed timeslot and reduce the effect caused by synchronization errors.Besides TDD technique, frequency division duplex (FDD) is also analyzed in this article. A novel AFDD (Asymmetric Frequency Division Duplex) technique is put forward in this article. AFDD allocate the uplink (downlink) bandwidth according to the service circumstance, it divide the uplink (downlink) frequency into several frequency points, all the uplink (downlink) frequency points make up uplink (downlink) frequency pool, each cell use the frequency points dynamically according to the actual service circumstance. The performance of AFDD\CDMA and AFDD\CDMA system is analyzed in this article, it show that: AFDD technique can improve the system’s capacity and efficiency of frequency resource.更多还原