frequency division multiplex system 中文意思是什麼
frequency division multiplex system
解釋
分頻多路傳輸方式-
Uestc is in charge of the tdd downlink that bases on fpga. ofdm ( orthogonal frequency division multiplex ) is the key technology of b3g system
現在已經進入項目的第二個階段,電子科技大學負責b3gtdd方式的下行鏈路設計,重點是基於fpga (現場可編程門陣列)的實現研究。 -
Initially, pdh was introduced to improve and replace the obsolete analog frequency division multiplex ( fdm ) system. however, it was soon found that pdh had shortcomings such as difficulty in management, high construction cost, limited applications and lack of connectivity standards at the optical layer. thus, in the early 1990s, synchronous digital hierarchy ( sdh ) was introduced in the transmission system
Pdh最初引入是為了改進和替代老式的模擬頻分復用器系統,但很快被發現pdh管理困難、造價高、應用范圍窄,且缺乏在光層面上的連接標準,因此90年代初期, sdh ( synchronousdigitalhierarchy )標準被首先引入了傳輸系統。 -
Multicarrier wireless communications have been widely investigated in the past decades. recently, two - dimensional spread spectrum ( 2d - ss ) system has drawn a lot of attention because of its full utilization of spreading characteristics in the frequency domain and time domain. compared with multicarrier code division multiplex access ( mc - cdma ), 2d - ss system can effectively mitigate multiple access interference ( mai ) due to spreading in the time domain
當前多載波無線通信技術得到了廣泛的研究,二維擴頻通信系統是近年來提出的新的擴頻通信方式,由於二維擴頻系統從時域和頻域上分別對數據信號進行頻譜擴展,因此它同時具有時域擴頻和頻率擴頻通信系統的特點,是對傳統的一維時域直接序列擴頻和多載波擴頻的推廣。
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