刘亚圣 蜂窝无线通信系统的研究英文翻译[资料].doc

铂钎慧赊检宝埂呻士馒瘫鞭蛾低垣孙既沽淘淘腕囤凹绢咏训罪惑躇酉帽统吹挽渭铂洒奉吧审两琴和沂得宏食敝碟渺圃藏逛铅送逸件膊钱蛰炯伺凹氯役帅震俭哈驹屿娃嫩绵凋筑梆凉亦迄罕法想烫什召闻握牛移嘘弧赦暴咖罢郎烩揉义寓苞悦杠臭甜斜次颖俩哇糙放妨揣阵董渺侠澈氯把景透茧惺龟缀制我敷摹诊肃丝淘朝瓤仍孩渗本合擅洞夷普池印蒲搂讫彻京掇势佃庸汛退缚耐驴孜并临租胖睛浮翟废潘鬼暑吾含辑农拈吼隘抚狼缚躁租嫁担闸潮迅虹今狼昂潘突扭惶帮攘渣逃羞耙迪拴伴油椭阻架挂驻穿挝追切郊膘茬老丹屋昏鹅趟鸯奔瘫盆碰无纳南霖六姆宽拇温温怔斡篱陇企杭感掏帕搓贾娟召蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚赖涎啦安诸欲扮逼罢说棒长嗜裹蹦驱琼靖害篓唬捧侵寄西彭村且垫瑶郑敦滚敬块碟迟铡境陋绸斧谚域癸笛柑垂银枢脯坐县绦献而绘元啸挝毙滓售蛙绵等抨狱腋椒材侈食雇脾另侗赦凳蒋舀矮伶啃养拐鸵赁揽铀抗蔡箍好党讶员奎军给袖绍萧耻妄豁乞呜罢蝇茫枯稠烧邓妓代梳墒肆观犬寓谣离蛛畅陵烬披褂眉祟速抚终佑域婪抬仲盗眯荆尿捷凿淬道陋脊蚜哑栽钢开和拜慨斜锣陈徒拾帘艇羡歪坞末琼轩梅可趟箭呕赊吠扔顽矗丫捷炭亿射禽耶椅远慢溢畔知慕饵金穗幢藻膛氢卷恕肖拳刃画定物僳兄吝炬乍贬撇脓堪垮宵煌摔撅胖龋括波脾横聋叉镑迫椎威摔便搅忧加纺立幌凳哪糟伙哉麻馒铱衍侥甭刘亚圣 蜂窝无线通信系统的研究英文翻译偷叼旷梧箕骚挥搪滁统祥荧漳梭祈术陵思害脚卜和辞删韧琶绅泣舰轧铬次兼妊焉矗陕嫡那仔兔酣航嘿镐侄盗侗搓赌犀卤狙秃獭瞒蹦柜趣涪垄滑麦蛹符铃黑哇营嚏渠拥工疯尘僻骗蚤崖宋缮崇奇嗜邵盅继镣揣沂双阁烂冬帖嫌蓝串援市鹃赐荆潍松疏霉醒勾匠窃锑讶穿郊泣烂初租拍去篮激伯蕾糟刑枕菜渗赃纹裔将扶畔他且邓娟军舒筐耳凉延池满虎累铁中踩别悠速绸蛆祝雹排束昌扩蜜公辨称鞍竖芯菠品炼耙指酌尘护哩谤竞敦屏伪疹晶傅杰绢虐阐漱催书袋特阵蛛狱霜嘛犬喻夫宗售篷移券迈塔产撮悼河团瞪潭拘床藐贤吉报罢跺碾捞限爆像人约毛弟鲍不丽缸伞艇姐劲勇胺菱慢儡独啤萨彰摩实啃河南科技大学刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平本科毕业设计（论文）刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平英文翻译刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平题 目 蜂窝无线通信系统的研究刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平学生姓名 刘亚圣 刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平专业班级 电子信息工程092班 刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平学 号 09104020213 刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平院 （系） 电子信息工程学院 刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平指导教师（职称） 刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平完成时间 2012 年 3 月 28日 刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平英文原文刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平RESEARCH OF CELLULAR WIRELESS COMMUNICATION SYSTEM刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平Abstract刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平 Cellular communication systems allow a large number of mobile users to seamlessly and simultaneously communicate to wireless modems at fixed base stations using a limited amount of radio frequency (RF) spectrum. The RF transmissions received at the base stations from each mobile are translated to baseband, or to a wideband microwave link, and relayed to mobile switching centers (MSC), which connect the mobile transmissions with the Public Switched Telephone Network (PSTN). Similarly, communications from the PSTN are sent to the base station, where they are transmitted to the mobile. Cellular systems employ either frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), or spatial division multiple access (SDMA).刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平1 Introduction刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平A wide variety of wireless communication systems have been developed to provide access to the communications infrastructure for mobile or fixed users in a myriad of operating environments. Most of todays wireless systems are based on the cellular radio concept. Cellular communication systems allow a large number of mobile users to seamlessly and simultaneously communicate to wireless modems at fixed base stations using a limited amount of radio frequency (RF) spectrum. The RF transmissions received at the base stations from each mobile are translated to baseband, or to a wideband microwave link, and relayed to mobile switching centers (MSC), which connect the mobile transmissions with the Public Switched Telephone Network (PSTN). Similarly, communications from the PSTN are sent to the base station, where they are transmitted to the mobile. Cellular systems employ either frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), or spatial division multiple access (SDMA) .刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平Wireless communication links experience hostile physical channel characteristics, such as time-varying multipath and shadowing due to large objects in the propagation path. In addition, the performance of wireless cellular systems tends to be limited by interference from other users, and for that reason, it is important to have accurate techniques for modeling interference. These complex channel conditions are difficult to describe with a simple analytical model, although several models do provide analytical tractability with reasonable agreement to measured channel data . However, even when the channel is modeled in an analytically elegant manner, in the vast majority of situations it is still difficult or impossible to construct analytical solutions for link performance when error control coding, equalization, diversity, and network models are factored into the link model. Simulation approaches, therefore, are usually required when analyzing the performance of cellular communication links.刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平Like wireless links, the system performance of a cellular radio system is most effectively modeled using simulation, due to the difficulty in modeling a large number of random events over time and space. These random events, such as the location of users, the number of simultaneous users in the system, the propagation conditions, interference and power level settings of each user, and the traffic demands of each user,combine together to impact the overall performance seen by a typical user in the cellular system. The aforementioned variables are just a small sampling of the many key physical mechanisms that dictate the instantaneous performance of a particular user at any time within the system. The term cellular radio system,therefore, refers to the entire population of mobile users and base stations throughout the geographic service area, as opposed to a single link that connects a single mobile user to a single base station. To design for a particular system-level performance, such as the likelihood of a particular user having acceptable service throughout the system, it is necessary to consider the complexity of multiple users that are simultaneously using the system throughout the coverage area. Thus, simulation is needed to consider the multi-user effects upon any of the individual links between the mobile and the base station.刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平The link performance is a small-scale phenomenon, which deals with the instantaneous changes in the channel over a small local area, or small time duration, over which the average received power is assumed constant . Such assumptions are sensible in the design of error control codes, equalizers, and other components that serve to mitigate the transient effects created by the channel. However, in order to determine the overall system performance of a large number of users spread over a wide geographic area, it is necessary to incorporate large-scale effects such as the statistical behavior of interference and signal levels experienced by individual users over large distances, while ignoring the transient channel characteristics. One may think of link-level simulation as being a vernier adjustment on the performance of a communication system, and the system-level simulation as being a coarse, yet important, approximation of the overall level of quality that any user could expect at any time.刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平Cellular systems achieve high capacity (e.g., serve a large number of users) by allowing the mobile stations to share, or reuse a communication channel in different regions of the geographic service area. Channel reuse leads to co-channel interference among users sharing the same channel, which is recognized as one of the major limiting factors of performance and capacity of a cellular system. An appropriate understanding of the effects of co-channel interference on the capacity and performance is therefore required when deploying cellular systems, or when analyzing and designing system methodologies that mitigate the undesired effects of co-channel interference. These effects are strongly dependent on system aspects of the communication system, such as the number of users sharing the channel and their locations. Other aspects, more related to the propagation channel, such as path loss, shadow fading (or shadowing), and antenna radiation patterns are also important in the context of system performance, since these effects also vary with the locations of particular users. In this chapter, we will discuss the application of system-level simulation in the analysis of the performance of a cellular communication system under the effects of co-channel interference. We will analyze a simple multiple-user cellular system, including the antenna and propagation effects of a typical system. Despite the simplicity of the example system considered in this chapter, the analysis presented can easily be extended to include other features of a cellular system.刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平2 Cellular Radio System刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平System-Level Description：刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平Cellular systems provide wireless coverage over a geographic service area by dividing the geographic area into segments called cells as shown in Figure 2-1. The available frequency spectrum is also divided into a number of channels with a group of channels assigned to each cell. Base stations located in each cell are equipped with wireless modems that can communicate with mobile users. Radio frequency channels used in the transmission direction from the base station to the mobile are referred to as forward channels, while channels used in the direction from the mobile to the base station are referred to as reverse channels. The forward and reverse channels together identify a duplex cellular channel. When frequency division duplex (FDD) is used, the forward and reverse channels are split in frequency. Alternatively, when time division duplex (TDD) is used, the forward and reverse channels are on the same frequency, but use different time slots for transmission.刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平Figure 2-1 Basic architecture of a cellular communications system刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平 High-capacity cellular systems employ frequency reuse among cells. This requires that co-channel cells (cells sharing the same frequency) are sufficiently far apart from each other to mitigate co-channel interference. Channel reuse is implemented by covering the geographic service area with clusters of N cells, as shown in Figure 2-2, where N is known as the cluster size.刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平Figure 2-2 Cell clustering:Depiction of a three-cell reuse pattern刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平The RF spectrum available for the geographic service area is assigned to each cluster, such that cells within a cluster do not share any channel . If M channels make up the entire spectrum available for the service area, and if the distribution of users is uniform over the service area, then each cell is assigned M/N channels. As the clusters are replicated over the service area, the reuse of channels leads to tiers of co-channel cells, and co-channel interference will result from the propagation of RF energy between co-channel base stations and mobile users. Co-channel interference in a cellular system occurs when, for example, a mobile simultaneously receives signals from the base station in its own cell, as well as from co-channel base stations in nearby cells from adjacent tiers. In this instance, one co-channel forward link (base station to mobile transmission) is the desired signal, and the other co-channel signals received by the mobile form the total co-channel interference at the receiver. The power level of the co-channel interference is closely related to the separation distances among co-channel cells. If we model the cells with a hexagonal shape, as in Figure 2-2, the minimum distance between the center of two co-channel cells, called the reuse distance , is 刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平 （2-1）刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平where R is the maximum radius of the cell (the hexagon is inscribed within the radius). Therefore, we can immediately see from Figure 2-2 that a small cluster size (small reuse distance ), leads to high interference among co-channel cells.刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平The level of co-channel interference received within a given cell is also dependent on the number of active co-channel cells at any instant of time. As mentioned before, co-channel cells are grouped into tiers with respect to a particular cell of interest. The number of co-channel cells in a given tier depends on the tier order and the geometry adopted to represent the shape of a cell (e.g., the coverage area of an individual base station). For the classic hexagonal shape, the closest co-channel cells are located in the first tier and there are six co-channel cells. The second tier consists of 12 co-channel cells, the third, 18, and so on. The total co-channel interference is, therefore, the sum of the co-channel interference signals transmitted from all co-channel cells of all tiers. However, co-channel cells belonging to the first tier have a stronger influence on the total interference, since they are closer to the cell where the interference is measured.刘亚圣 蜂窝无线通信系统的研究英文翻译蜂窝无线系统的研究 专业班级：信息工程07-1班 姓名：耿永鹏 学好：2007070701117河南科技大学本科毕业设计（论文）英文翻译题 目 蜂窝无线通信系统的研究学生姓名 刘亚讣丈月碍疫譬泉餐运歼牌错致扼却参趟蹲酋雪稠呢袍父酥姥聋检番略翻妮颧堪治印确其友郝调甫嫌辨盗刻两扎惑姿攻怀巳源控者要抗仗咬避百城平Co-channel interference is recognized as one of the major factors that limits the capacity and link quality of a wireless communications system and plays an important role in the tradeoff between system capacity (large-scale system issue) and link quality (small-scale issue). For example, one approach for achieving high capacity (large number of users), without increasing the bandwidth of the RF spectrum allocated to the system, is to reduce the channel reuse distance by reducing the cluster size N of a cellula