本文關(guān)鍵詞： 符號(hào)定時(shí)估計(jì) 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(wú)線數(shù)字通信系統(tǒng)中,全數(shù)字化接收機(jī)以固定的時(shí)鐘進(jìn)行采樣,容易出現(xiàn)符號(hào)采樣偏差,需要在接收端進(jìn)行估計(jì)并補(bǔ)償。針對(duì)符號(hào)定時(shí)估計(jì)的問(wèn)題,提出了一種基于自相關(guān)系數(shù)插值的迭代符號(hào)定時(shí)同步算法。該算法分為兩個(gè)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(duì)接收信號(hào)進(jìn)行匹配濾波,再利用滑動(dòng)自相關(guān)的方法對(duì)同步頭序列進(jìn)行相關(guān)運(yùn)算,當(dāng)超過(guò)同步門限時(shí),開(kāi)始進(jìn)行同步跟蹤對(duì)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(guò)程中需要先根據(jù)估計(jì)的時(shí)延值生成群時(shí)延的匹配濾波器以對(duì)接收信號(hào)進(jìn)行補(bǔ)償,再利用最小二乘逼近函數(shù)度量,同時(shí),采用高斯插值的方法提高搜索速度以獲取精確的估計(jì)結(jié)果。與傳統(tǒng)算法相比,該算法降低了同步搜索過(guò)程中的計(jì)算復(fù)雜度,同時(shí)利用迭代搜索易于實(shí)現(xiàn)高精度的符號(hào)定時(shí)同步。仿真結(jié)果表明:對(duì)于長(zhǎng)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(shí),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(duì)±1/2符號(hào)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(jì),適合無(wú)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(guó)防科技預(yù)研基金資助項(xiàng)目(11J3.4.2)
【分類號(hào)】：TN713;TN911.7;TN914
【正文快照】： 在無(wú)線數(shù)字通信系統(tǒng)中,傳輸信號(hào)容易受到時(shí)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(hào)補(bǔ)償[1]。符號(hào)定時(shí)采樣需要信號(hào)在其眼圖張開(kāi)最大的時(shí)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(shí)鐘進(jìn)行采樣[3],容易出現(xiàn)符號(hào)采樣偏差。符號(hào)采樣偏差會(huì)

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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(bào);1982年04期

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