Estimating spreading waveform of long-code direct sequence spread spectrum signals at a low signal-to-noise ratio

Zhang, Huaguo; Liu, Gan; Liao, Hong Shu; Wei, Ping; Li, L. P.

doi:10.1049/iet-spr.2011.0173

Cited by 15 publications

(19 citation statements)

References 13 publications

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“…Simulation results show that the proposed method has the potential to estimate the spreading sequences even in large system load scenario with low SNR. Furthermore, the proposed method can achieve a better performance comparing with other two existing algorithms proposed in [24,26]. This paper does not consider multipath effect since the assumption AS2 is severely violated in the multipath scenario [35].…”

Section: Resultsmentioning

confidence: 99%

“…, where L (L < G) denotes the duration of short-time segments in the process of the segmentation scheme. Therefore the complexity of the proposed algorithm is higher than that of the algorithm in [24] and that of the algorithm in [26].…”

Section: Computation Complexitymentioning

confidence: 92%

“…The effect of system load is studied by varying the number of users and measuring sign error rate in each case. For the purpose of comparison, we also implement the algorithm reported in [24,26], which have the potential to deal with the spreading sequence estimation for LC-CDMA signal. Number of hill climbers is fixed at 40 and SNR is fixed at −10 dB.…”

Section: Examplementioning

confidence: 99%

“…However, this method is restricted to single user scenario. By representing equivalently the LC-DSSS signal as a SC-DSSS signal with missing data, Zhang et al viewed the spreading sequence estimation problem as a low-rank matrix approximation problem [24]. This technique provides good estimation accuracy in single user case.…”

Section: Introductionmentioning

confidence: 99%

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Blind spreading sequence estimation algorithm for long‐code DS‐CDMA signals in asynchronous multi‐user systems

Liang

Wang

et al. 2017

IET signal process.

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Despreading signal at receiver side requires prior knowledge of the spreading sequences in direct-sequence code division multiple access (DS-CDMA) system. However, the knowledge of spreading sequences is always unknown to the receiver in non-cooperative communication. Therefore the receiver has to estimate the spreading sequences in a blind manner. This study presents a novel algorithm to estimate the spreading sequences for asynchronous long-code (LC) DS-CDMA signals. By investigating the projection characteristics of the signal subspace, the authors treat the spreading sequence estimation problem as a discrete optimisation search problem that can be solved efficiently by modern optimisation search methods. Moreover, they design a successive subspace deflation scheme to alleviate interference from other users. Numerical experiments demonstrate that the proposed algorithm provides good estimation of the spreading sequences for LC-DS-CDMA signals. Compared with the existing algorithms, the proposed algorithm exhibits much better performance in large system load scenario with low signal-to-noise ratio.

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Section: Resultsmentioning

confidence: 99%

Section: Computation Complexitymentioning

confidence: 92%

Section: Examplementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Blind spreading sequence estimation algorithm for long‐code DS‐CDMA signals in asynchronous multi‐user systems

Liang

Wang

et al. 2017

IET signal process.

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“…Bu çalışmada uzun kodlu DS-SS sinyalleri ele alındığı için Z > G olmalıdır [7]. (2)'deki denklemin (i. sensör çıkışının) frekans bölgesindeki ifadesi şu şekildedir,…”

Section: Introductionunclassified

Detection of low probability of intercept signals in low SNR using multichannel sensor arrays

Uysal

Filik

2014

2014 22nd Signal Processing and Communications Applications Conference (SIU)

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Özetçe-Bu çalışmada, tespit olasılığı düşük (Low-Probabilityof-Intercept, LPI) sinyallerin, uzaysal olarak dağıtılmış çok kanallı geniş-bant sensör dizisi kullanılarak yüksek gürültü altında, herhangi bir önsel bilgi ve varsayım gerekmeksizin tespiti için bir yöntem önerilmektedir. Önerilen tespit yöntemi, geniş-bant uzaysal ilinti matris elemanlarının özdeğer oranlarını (EigenValue Ratio, EVR) test istatistiği olarak kullanmaktadır. Yöntemin çok uzun kodlu yayılı spektrum sinyallerini düşük sinyal-gürültü oranın (SNR)'da kararlı bir şekilde tespit edebildiği benzetimlerle gösterilmiştir. Ayrıca önerilen yöntemin çokyollu yansıma durumunda performansının etkilenmediği benzetimlerle gösterilmiştir. Anahtar Kelimeler -yayılı spektrum haberleşmesi; sinyal tespiti; ilinti matrisleri; sensör dizileri.Abstract-In this paper, a method is proposed for the detection of low probability of intercept, LPI signals in high noise without prior knowledge and assumption using spatially distributed multichannel wideband sensor array. The proposed detection method uses eigenvalue ratios (EVR) of wideband spatial covariance matrix as test statistic. It is shown in simulations that the proposed method can detect long code spread spectrum signals in a stable way even in low SNR. In addition, it is also shown in simulations that the proposed method is inherently resistive to the multipath reflections.

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Estimating Symbol Duration of Long-Code Direct Sequence Spread Spectrum Signals at a Low Signal-to-Noise Ratio

Huang

Liang

Wang

2020

Wireless Pers Commun

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Estimating spreading waveform of long-code direct sequence spread spectrum signals at a low signal-to-noise ratio

Cited by 15 publications

References 13 publications

Blind spreading sequence estimation algorithm for long‐code DS‐CDMA signals in asynchronous multi‐user systems

Blind spreading sequence estimation algorithm for long‐code DS‐CDMA signals in asynchronous multi‐user systems

Detection of low probability of intercept signals in low SNR using multichannel sensor arrays

Estimating Symbol Duration of Long-Code Direct Sequence Spread Spectrum Signals at a Low Signal-to-Noise Ratio

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