Impact of multiple access interference on capacity of a multi-rate cdma system 系統(tǒng)中多址干擾對(duì)系統(tǒng)容量的影響
Moreover, multiple access interference due to the existence of other users was analyzed 此外,還對(duì)多個(gè)用戶(hù)情形下的多址干擾進(jìn)行了分析。
multiple access interference ( mai ) and multipath fading are two major factors limiting performances of cdma communication systems 多址干擾和多徑衰落是限制cdma系統(tǒng)性能的主要因素。
In cdma system, multiple access interference limits the capacity of any system using conventional single user correlation or matched filter receivers 在cdma系統(tǒng)中,采用常規(guī)的單用戶(hù)相關(guān)或匹配濾波的方法,多址干擾限制了系統(tǒng)容量。
If the assigned spreading codes are orthogonal and signals are transmitted through a flat fading channel, there will be no multiple access interference ( mai ) 如果所有用戶(hù)采用理想正交擴(kuò)頻碼并且通過(guò)同步平坦衰落信道,系統(tǒng)中將不會(huì)存在多址干擾(mai:multipleaccessinterference)。
But mc-cdma system still has some problems . some of the most important sources for performance degradation of mc-cdma systems are carrier frequency offset and the multiple access interference ( mai ) 然而多載波cdma系統(tǒng)也存在一些問(wèn)題,多址干擾和頻率偏移等問(wèn)題會(huì)帶來(lái)明顯的性能下降。
But in tdd-cdma system, there are many problems to solve including multipath fading, perspective effect, multiple access interference which influence its capacity and quality of service 同其它c(diǎn)dma系統(tǒng)一樣,tddcdma系統(tǒng)在無(wú)線傳輸中仍然存在著多徑衰落、時(shí)延擴(kuò)展、遠(yuǎn)近效應(yīng)、多址干擾等問(wèn)題,直接影響了系統(tǒng)的容量和服務(wù)質(zhì)量。
Due to multipath effect, multiple access interference ( mai ), near-far effect, and mainly the non-li ne-of-sight ( nlos ) propagation, the errors in the estimated location parameters and position location occur 在cdma蜂窩網(wǎng)的定位中,引起定位參數(shù)估計(jì)誤差與定位誤差的因素有非視距傳播效應(yīng)、多徑傳播效應(yīng)、多址干擾及遠(yuǎn)近效應(yīng)。
In this dissertation, multiuser detection and space-time processing are combined to suppress multiple access interferences and inter-symbol interferences ( isi ) jointly in multipah fading channels with large delay spread 本文組合多用戶(hù)檢測(cè)和空時(shí)處理技術(shù),在大時(shí)延擴(kuò)展的多徑衰落信道條件下,研究多址干擾和符號(hào)間串?dāng)_的聯(lián)合抑制。
This paper analyse all kinds of interference of tdd-cdma system in detail, establish interference model; based on this, establish multiple access interference module of uplink . in some sense, tdd-cdma is based on smart antenna 本論文詳細(xì)研究了tddcdma系統(tǒng)存在的各種干擾,建立了干擾模型;并以上行鏈路為例,建立了上行鏈路多址干擾模型。