共查询到20条相似文献,搜索用时 140 毫秒
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针对多径信道环境下非同步长码DS-CDMA信号扩频码及信息序列等参数的联合估计问题,该文提出了基于序贯蒙特卡罗(SMC)的盲估计算法。该算法采用混合重要密度函数对联合后验分布模型进行抽样,并迭代计算重要性权值,以完成所需状态参量的估计。同时为了减少算法的计算量,在算法的实现过程中,先估计出各用户的扩频码,再对观测数据进行处理,从而修正原有的迭代步骤,提出一种修正的SMC算法。仿真结果验证了算法对多种情况的适应性,且在时变的多径信道环境下也能获得较好的估计性能。 相似文献
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提出了一种基于并行卡尔曼滤波的递推最小二乘算法.利用最小二乘算法对卡尔曼滤波的并行多路收敛输出值进行二次优化估计.将本算法应用于正弦波测频,与只采用卡尔曼滤波的算法相比,可使频率估计精度得到明显提高.仿真证明在信噪比0~100 dB区间内采用本算法为卡尔曼滤波算法的测频误差的1/10左右. 相似文献
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在非相干分布式非圆信号波达方向(DOA)估计中,针对利用信号非圆特性后输出矩阵维数扩展带来的较大运算量问题,该文提出一种基于互相关抽样分解的DOA快速估计算法。该算法仅需要从子阵间的扩展互相关矩阵中抽样出少量行元素和列元素,构成两个低维子矩阵,进而通过低秩近似分解便可快速地同时求出左右奇异矢量,即分别对应两个子阵的信号子空间,避免了计算整个互相关矩阵及其奇异值分解运算;最后利用两个子阵信号子空间的旋转不变性通过最小二乘得到DOA估计。仿真分析表明,当行列抽样数大于信源数的两倍时,所提算法与直接基于互相关矩阵奇异值分解的非相干分布式非圆信号DOA估计算法性能相近,但复杂度得到了大幅度降低;而相比于传统的低复杂度非相干分布源DOA估计算法,所提算法利用信号非圆特性具有更高的估计性能。 相似文献
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该文针对时变频率选择性衰落信道下高阶连续相位调制(CPM)信号盲均衡中存在的均衡性能较差、复杂度较高以及收敛速度慢等问题,从双向自适应信道均衡的角度出发,将线性调制信号均衡中使用的前后向自适应软输入软输出(FABA-SISO)算法推广,建立一种新的基于FABA-SISO的信道盲均衡方法,并结合逐幸存处理(PSP)思想和Kalman滤波,提出一种适用于高阶CPM信号的自适应盲均衡算法。该算法通过使用FABA-SISO算法,同时利用过去、现在和将来的观察数据进行Kalman滤波信道估计,有效改善了信道估计的精度,同时使用PSP算法来降低系统的复杂度,使得算法具有较好的工程应用性。仿真结果表明所提算法具有良好的盲均衡性能以及收敛性。 相似文献
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Blind adaptive multiuser detection based on Kalman filtering 总被引:9,自引:0,他引:9
Xian-Da Zhang Wei Wei 《Signal Processing, IEEE Transactions on》2002,50(1):87-95
Although several Kalman filtering algorithms have been presented for adaptive multiuser detection, none is "blind" due to requiring training data sequences and/or more knowledge than the spreading waveform and delay of the desired user. This paper proposes a novel blind adaptive multiuser detector based on Kalman filtering and compares it with previously published LMS and RLS algorithms for blind adaptive multiuser detection. It is shown that the steady-state excess output energy of the Kalman filtering algorithm is identically zero for a stationary environment. Simulation results show the effectiveness of the new Kalman filtering algorithm 相似文献
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研究了空时编码多载波码分多址系统(STBC MC—CDMA)盲信道估计技术。根据信道位于信号子空间的特点,提出基于信号子空间投影线性约束恒模算法(SP—LCCMA)的盲信道估计,避免了噪声子空间信道估计的缺点,将估计信道应用于STBC MC—CDMA系统多用户检测。仿真结果表明,提出算法的收敛速度和信干噪比(SINR)性能优于一般恒模算法。 相似文献
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Orthogonal frequency division multiplexing (OFDM) is a multi-carrier modulation scheme, which has been adopted for several
wireless standards. In order to fully exploit the benefits of an OFDM system, estimation of the channel state information
must be performed. Moreover a well-known problem of OFDM is its sensitivity to frequency offset between the transmitted and
received carrier frequencies. This frequency offset introduces inter-carrier interference in the OFDM signal. In this paper
we address the problem of jointly tracking the channel and frequency offset based on a Sequential Monte Carlo filtering approach.
The proposed algorithm works in a decision-directed way, thus does not require the use of pilot symbols, providing a worth-mentioned
increase in the useful data rate. Through simulations we demonstrate the efficiency of this approach against a similar approach
where the Extended Kalman Filter is used. Moreover our method is compared with two recently proposed pilot-based methods. 相似文献
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