共查询到15条相似文献,搜索用时 234 毫秒
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该文基于正交序列集,研究了一类新的零相关区(ZCZ)非周期互补序列(ZACS)集构造方法,所得到的序列集参数达到最优,且在满足Z|N的条件下零相关区长度可以灵活选择。该方法所构造的序列具有理想的自相关性能和组内互补特性。通过调整参数q,可得到多个不同的序列集。同时,基于多电平完备序列,给出了一类高斯整数正交序列集的构造方法,得到的高斯整数正交序列集可以用于非周期互补序列集的构造。所提方法构造的零相关区非周期互补序列集用于多载波码分多址系统中可以降低多径干扰、多址干扰,也可以作为训练序列用于多输入多输出信道估计中。 相似文献
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该文基于正交序列集,研究了一类新的零相关区(ZCZ)非周期互补序列(ZACS)集构造方法,所得到的序列集参数达到最优,且在满足Z|N的条件下零相关区长度可以灵活选择.该方法所构造的序列具有理想的自相关性能和组内互补特性.通过调整参数q,可得到多个不同的序列集.同时,基于多电平完备序列,给出了一类高斯整数正交序列集的构造方法,得到的高斯整数正交序列集可以用于非周期互补序列集的构造.所提方法构造的零相关区非周期互补序列集用于多载波码分多址系统中可以降低多径干扰、多址干扰,也可以作为训练序列用于多输入多输出信道估计中. 相似文献
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高斯整数零相关区(ZCZ)序列集作为准同步码分多址(QS-CDMA)系统的地址序列不仅能抑制系统的多径干扰(MAI)和多址干扰(MPI),而且为系统提供高传输码率和高的频谱利用率,但目前这种地址序列的构造结果还较少,针对此问题本文提出了一种利用过滤操作构造高斯整数ZCZ序列集和完美高斯整数序列的方法.基于完美序列和周期ZCZ序列集本文获得了最佳或几乎最佳的高斯整数ZCZ序列集,同时基于完美序列构造了周期为奇数和偶数的完美高斯整数序列.本文的构造结果为高速QS-CDMA系统提供了更多的地址选择空间. 相似文献
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该文提出基于伪随机序列构造高斯整数序列的方法。基于长度为 pm-1的p 元伪随机序列,构造得到长度为pm-1的高斯整数序列,其阶数为p-1。该类高斯整数序列具有几乎完备的自相关性能,其异相自相关函数值仅存在p-2个非零值。并且该类高斯整数序列具有良好的平衡性,在无线通信与雷达系统中都有广泛的应用前景。 相似文献
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最佳高斯整数序列应用于通信系统不仅能抑制干扰,还可获得高的传输速率和频谱利用率.本文基于循环差集给出了构造自由度为2的最佳高斯整数序列的充要条件,比较现有文献,可获得更高能量效率的最佳高斯整数序列.同时,利用上采样和过滤技术扩展了最佳高斯整数序列的长度和自由度.本文方法能得到大量适于高速通信系统的最佳高斯整数序列,扩展了通信地址码的选择范围. 相似文献
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本文在考虑了码间干扰及量子噪声等实际因素影响的情况下,以Personick的高斯近似法为分析基础,得到了数字光脉冲电平数为任意整数,且这些光脉冲电平所出现的概率为任意分布时的数字光接收机灵敏度计算公式。 相似文献
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The construction of zero correlation zone (ZCZ) Gaussian integer sequence set was researched.Based on binary orthogonal matrices,ZCZ ternary sequence sets were constructed by adding zeros at first.Then the ternary ZCZ squences were transformed into Gaussian integer sequences by using a perfect Gaussian integer sequence without changing the ideal autocorrelation functions and crosscorrelation functions in the zero correlation zone.The proposed ZCZ Gaussian integer sequence sets are optimal or almost optimal with respect to the Tang-Fan-Matsufuji bound. 相似文献
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Constructions of perfect Gaussian integer sequences (PGIS) based on the cyclotomic classes were proposed.The PGIS with degree 3 and 5 were constructed respectively from the cyclotomic classes of order 2 and 4.The presented sequences with odd prime length have ideal autocorrelations.The methods solved the problem that the traditional constructions of PGIS from the cyclotomic classes have high computational complexity.As a result,this kind of sequences will be useful in the applications of wireless communications. 相似文献
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Both m-sequences and Gold sequences have been applied as the pseudonoise (PN) code in the code division multiple access (CDMA) scheme to enable distinct users to simultaneously share the available capacity of a common channel, which is called direct sequence CDMA (DS-CDMA). However, this scheme does not provide the required ideal periodic cross-correlation function property among various members of sequences within the same set. This paper proposes a new perfect Gaussian integer sequence (PGIS)-based CDMA scheme called PGIS-CDMA; in this scheme, the PN code of DS-CDMA is replaced by a set of PGISs. The intrinsic orthogonal property of PGIS can be applied to a CDMA system to achieve perfect cochannel interference separability under the ideal synchronism; it can also be adapted at the receiver to obtain diversity gain and improve the carry-to-interference ratio. These two concepts are further developed to implement two PGIS-CDMA configurations, and they can outperform DS-CDMA on the basis of Gold sequences that possess a favorable cross-correlation property for the CDMA scheme. 相似文献
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Cai Xuelian Li Jiandong Li Changle Chen Chen 《电子科学学刊(英文版)》2005,22(6):569-574
One of the principal disadvantages of Orthogonal Frequency Division Multiplexing (OFDM) is very sensitive to carrier frequency offset. The integer frequency offset has no effect on the orthogonality among the subcarriers, but it causes a circular shift and phase rotation of the received data symbols sequence, resulting in a Bit Error Rate(BER) of 0.5. In this paper, a novel integer frequency offset estimator for OFDM is derived based on maximum likelihood estimation technique and exploration of the differential relation between two consecutive OFDM data symbol sequences in frequency domain. Its performance is compared with the conventional method by computer simulations for the additive white Gaussian noise channel and a multipath fading channel. Simulation results show that the performance of the proposed estimator is better than the conventional estimator. 相似文献