sub-symbol 中文意思是什麼
sub-symbol
解釋
次符號-
In the synchronous techniques based pilot symbols, here propose a frequency offset estimating arithmetic using discrete pilot symbols. we pick up integer times sub - carrier frequency offset from the same ofdm symbol and estimate exact
此外，在頻偏估計方面，推導出短訓練序列前後兩段時域符號間的關系，並利用此進行粗頻偏估計，使頻率偏移的估計范圍大大增加。 -
The paper is arranged from up to down. from umts to utran, then nodeb and baseband processing are proposed, at last the downlink symbol rate dsp is the corn and importance of the paper. the paper tries to clear the relationship between systems and system and sub - system, and gives a complete concept to reader
從umts通信系統到utran的結構，然後關注到nodeb和基帶處理系統，最後是下行符號級處理dsp的具體實現。其中最後的實現是論文的核心和重點，論文也力求闡明各個系統之間以及系統與其子系統之間的關系，給讀者一個整體的概念和完整的認識。 -
In the future, we will increase the number of the frequency - hopped sub - bands. it will solve the inter - symbol interference ( isi ) perfectly. then the system will be used on the test out of labs
后續的工作只要把十六進制改為八進制（此工作不難）的數字頻移鍵控傳輸系統，藉以提高跳頻的子帶數目，即增加跳頻點，可期適于海上的應用。 -
Design a kind of sub - optimum digital prefilter. through the simulation of timing recovery loop which is n ' t added prefilter and which is added prefilter, discuss the convergence characteristic and compare the relation between timing jitter and signal to noise ratio, the relation between timing jitter and noise bandwidth of loop, the relation between symbol error ratio and signal to noise ratio
通過對加預濾波器后的定時恢復環的模擬，討論了環路的收斂情況，比較了所設計的數字預濾波器和無預濾波器時環路定時抖動與信噪比、定時抖動與環路噪聲帶寬、誤碼率與信噪比的數量關系，證實所設計的數字預濾波器對減少定時抖動非常有效。 -
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