本文關(guān)鍵詞： 符號定時估計 匹配濾波 自相關(guān)系數(shù) 迭代 高斯插值　出處：《工程科學(xué)與技術(shù)》2017年03期 　論文類型：期刊論文

【摘要】：在無線數(shù)字通信系統(tǒng)中,全數(shù)字化接收機(jī)以固定的時鐘進(jìn)行采樣,容易出現(xiàn)符號采樣偏差,需要在接收端進(jìn)行估計并補(bǔ)償。針對符號定時估計的問題,提出了一種基于自相關(guān)系數(shù)插值的迭代符號定時同步算法。該算法分為兩個步驟:粗同步與精同步。粗同步先利用零相濾波器或三相濾波器組對接收信號進(jìn)行匹配濾波,再利用滑動自相關(guān)的方法對同步頭序列進(jìn)行相關(guān)運算,當(dāng)超過同步門限時,開始進(jìn)行同步跟蹤對自相關(guān)系數(shù)進(jìn)行峰值搜索,以確定精同步搜索區(qū)間。精同步直接在搜索區(qū)間內(nèi)進(jìn)行迭代搜索,迭代過程中需要先根據(jù)估計的時延值生成群時延的匹配濾波器以對接收信號進(jìn)行補(bǔ)償,再利用最小二乘逼近函數(shù)度量,同時,采用高斯插值的方法提高搜索速度以獲取精確的估計結(jié)果。與傳統(tǒng)算法相比,該算法降低了同步搜索過程中的計算復(fù)雜度,同時利用迭代搜索易于實現(xiàn)高精度的符號定時同步。仿真結(jié)果表明:對于長度為64的同步頭序列,在高斯白噪聲信道條件下,信噪比 2 dB時,該算法利用兩次迭代即可逼近克拉美羅界;在信噪比為10 dB,針對±1/2符號周期內(nèi)的采樣偏差,本文算法的MSE性能均優(yōu)于升余弦插值、MMSE插值與多相濾波器組算法;在瑞利信道、CCIR中等信道以及CCIR壞信道下也能進(jìn)行有效的估計,適合無線數(shù)字通信系統(tǒng)的信道環(huán)境。
[Abstract]:In the wireless digital communication system, the all-digital receiver samples with a fixed clock, which is prone to the symbol sampling deviation, which needs to be estimated and compensated at the receiver, aiming at the problem of symbol timing estimation. An iterative symbol timing synchronization algorithm based on autocorrelation coefficient interpolation is proposed, which is divided into two steps:. Rough synchronization and fine synchronization. Coarse synchronization uses zero-phase filter or three-phase filter bank to filter the received signal. Then the sliding autocorrelation method is used to perform correlation operation on the synchronous head sequence. When the synchronization threshold is exceeded, the peak value of the autocorrelation coefficient is searched by synchronous tracking. In order to determine the precision synchronization search interval, the precision synchronization searches directly in the search interval. In the iterative process, the matched filter of group delay should be generated according to the estimated delay value to compensate the received signal. At the same time, Gao Si interpolation method is used to improve the search speed to obtain accurate estimation results, compared with the traditional algorithm. The algorithm reduces the computational complexity in the synchronous search process, and it is easy to achieve high precision symbol timing synchronization by iterative search. The simulation results show that the synchronization header sequence is 64 in length. Under the condition of Gao Si white noise channel, the signal-to-noise ratio (SNR) is 2 dB, and the algorithm can approach the Clemero bound by using two iterations. When the SNR is 10 dB, the MSE performance of the proposed algorithm is superior to that of the raised cosine interpolation and polyphase filter banks for the sampling deviations within 鹵1/2 symbol periods. In Rayleigh channel, CCIR medium channel and CCIR bad channel can also be effectively estimated, which is suitable for wireless digital communication system channel environment.
【作者單位】： 哈爾濱工程大學(xué)信息與通信工程學(xué)院;武漢船舶通信研究所;
【基金】：船舶工業(yè)國防科技預(yù)研基金資助項目(11J3.4.2)
【分類號】：TN713;TN911.7;TN914
【正文快照】： 在無線數(shù)字通信系統(tǒng)中,傳輸信號容易受到時延、相位偏移、頻率偏移以及衰落的影響,需要在接收端進(jìn)行信號補(bǔ)償[1]。符號定時采樣需要信號在其眼圖張開最大的時刻采樣,以保證噪聲與干擾最小化[2];而全數(shù)字化接收機(jī)以固定的時鐘進(jìn)行采樣[3],容易出現(xiàn)符號采樣偏差。符號采樣偏差會

【相似文獻(xiàn)】

相關(guān)期刊論文 前1條

1 陳汝鈞;CCD復(fù)位噪聲相關(guān)性的分析[J];華中工學(xué)院學(xué)報;1982年04期

，

本文編號：1442785