異步帶限D(zhuǎn)S-CDMA系統(tǒng)在多徑衰落信道下的子空間時(shí)延序貫估計(jì)算法
SUBSPACE-BASED TIME DELAY SEQUENTIAL ESTIMATION ALGORITHM FOR ASYNCHRONOUS BANDLIMITED DS-CDMA SYSTEMS IN MULTIPATH FADING CHANNELS
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摘要: 該文提出了適合于異步DS-CDMA系統(tǒng)在多徑衰落信道下的子空間時(shí)延序貫估計(jì)算法,稱為MUSIC-SEA算法。該算法引入了序貫估計(jì)思想,將已估時(shí)延信息融入后續(xù)時(shí)延估計(jì)過(guò)程中,整個(gè)時(shí)延估計(jì)過(guò)程為:首先估計(jì)噪聲子空間,然后依次對(duì)每個(gè)時(shí)延進(jìn)行粗略估計(jì)和精確搜索。給出了MUSIC-SEA算法的迭代執(zhí)行方法,并進(jìn)行了性能分析和計(jì)算機(jī)仿真。結(jié)果表明,MUSIC-SEA算法能有效除去多徑間的相互影響,提高時(shí)延正確估計(jì)概率和時(shí)延估計(jì)精度。
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關(guān)鍵詞:
- CDMA; 時(shí)延估計(jì); 多徑衰落; 子空間
Abstract: A subspace-based time delay sequential estimation algorithm named MUSIC-SEA is presented for asynchronous bandlimited DS-CDMA systems in multipath fading channels. The sequential estimation idea is introduced, and the knowledge of the estimated time delays is involved in the subsequent estimation procedures. The whole procedure can be described as follows: the noise subspace is estimated first, and then coarse estimation and fine search of time delay are implemented for every time delay sequentially. The iterative steps are presented, the performance of the algorithm is analyzed, and simulations are carried out. The results show that the algorithm can mitigate the interference of multipath and provide time delay estimation with high probabilities and high accuracy. -
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