移去線串 的英文怎麼說
中文拼音 [yíqùxiànchuàn]
移去線串
英文
removestring-
Firstly, in wireless environment, receiver has no know the time delay between transmitter and itself. in ofdm system, ofdm data is transmitted as one symbol, so in order for correct demodulation, the correct start of symbol should be got from ofdm system to reduce the effect of isi. secondly, the high frequency utilization in ofdm is based on the orthogonal properties of sub carriers. if frequency offset is generated, the orthogonal properties among sub carriers will lost, that will cause inter carrier interference ( ici ) and high ber of system
Ofdm技術也存在著一些缺陷，首先，在無線環境中傳輸的ofdm信號對定時要求高，為了減少碼間串擾（ isi ）影響，必須從接收信號中提取出正確的符號起始位;其次， ofdm系統對頻率偏移敏感， ofdm技術的高頻譜利用率和傳輸可靠性均以子載波的正交性為基礎，如果接收機和發射機之間發生頻率偏移，子載波之間就會失去正交性，導致嚴重的子載波間干擾（ ici ） ，降低系統性能。
分享友人