Acquisition of PN code with adaptive threshold forDS/SScommunications

Kim, Chang Joo; Hwang, Tae Won; Lee, Hyuck Jae; Lee, Hwang Soo

doi:10.1049/el:19970916

Cited by 17 publications

(8 citation statements)

References 4 publications

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“…We observe that the proposed system exhibits the same performances as the AHAP(0) and performs slightly better than the OSHAP. Noting also that the proposed system reduces to the AHAP(0) which is known to be the most appropriate processor in such a homogeneous environment [11]. Figure 7a and b give a performance comparison for the proposed system, the AHAP(3) and the OSHAP in the presence of two and six multipaths with uniform and exponentially decaying MIP, respectively.…”

Section: Numerical Resultsmentioning

confidence: 99%

Adaptive Hybrid Acquisition of PN Sequences Based on Automatic Multipath Cancellation in Frequency-Selective Rayleigh Fading Channels

Hacini

Farrouki

Hammoudi

2010

Wireless Pers Commun

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A hybrid PN-code acquisition scheme is proposed and studied for direct sequence code division multiple access communications in frequency-selective Rayleigh fading channels. The most important feature of the proposed system is its ability to dynamically estimate the number of multipath signals that may lie in the reference channel. The basic idea of the considered algorithm is to sort the partial correlations and carry out successive censoring tests by updating the noise estimation until the first path synchronization. Exact expressions for the probability of false alarm and the mean acquisition time are derived. The performances of the proposed system are then studied and compared with those of the adaptive hybrid acquisition processor (AHAP) and the ordered statistic hybrid acquisition processor (OSHAP). The effects of various channel parameters on the acquisition performance, namely the number of resolvable paths, the multipath intensity profile and the signal-to-noise ratio are also investigated. Numerical results show that the proposed acquisition scheme outperforms the conventional ones which are based on AHAP and OSHAP algorithms.

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Section: Numerical Resultsmentioning

confidence: 99%

Adaptive Hybrid Acquisition of PN Sequences Based on Automatic Multipath Cancellation in Frequency-Selective Rayleigh Fading Channels

Hacini

Farrouki

Hammoudi

2010

Wireless Pers Commun

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“…Reference [2][3][4] discussed algorithms for dynamically adjusting threshold according to the incoming signal power. This method is not appropriate for laser radar since its signal length cannot be too long, and the convergence ratio of the algorithms largely affects the decoding ratio.…”

Section: Proposed Methods For Decoding Laser Radar Signalmentioning

confidence: 99%

“…The upper figure shows the case of setting threshold at 1 Th when the signal power in code 1 time slot is weak. The lower one shows that the threshold is adjusted to 2 Th when strong signal is received. On the other hand, in (b), threshold is fixed at 1 Th .…”

Section: Proposed Methods For Decoding Laser Radar Signalmentioning

confidence: 99%

“…However, the optimal threshold is impossible to be fixed since the strength of the backscatter is affected by many factors such as target range, size, reflection ratio, etc, and is not a fixed value. Similar problem in wireless communications is solved by adjusting threshold according to the incoming signal power [2][3][4]. In laser radar situation, limited by laser safety regulation and laser radar scan velocity, only short codes are available.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modulated laser radar decoding by inter symbol interference

et al. 2011

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Pseudo Random Noise (PN) coded laser radar can improve the target detection ability without the demand on high power laser. However, the reflected echoes are generally so weak that they are buried in the thermal noise of the receiver, which raises the problem of choosing an optimal threshold for correctly decoding them since the power of echoes varies from time to time, and the voltage of light generated electrical signal by photo diode (PD) is always positive. In this work, we firstly show the problem we are going to discuss. Then, a novel method basing on Inter Symbol Interference (ISI) is proposed for solving the problem. Next, numerical simulations and experiments are performed to validate the method. Finally, we discuss the obtained results theoretically.

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“…Literature [1] - [3] proposed three adaptive threshold schemes, that is, MLAP, OSAP, AAP. They all adjust thresholds according to the decision variable (related accumulated value) and make great progress when compared with the fixed threshold detection.…”

Section: Introductionmentioning

confidence: 99%

Adaptive Acquisition Threshold Algorithm Based on Mean Energy

Han

Jia

2013

2013 Third International Conference on Instrumentation, Measurement, Computer, Communication and Control

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An adaptive acquisition threshold algorithm based on mean energy (MEAT) was proposed. Conditional probability of acquisition decision variable in MEAT was analyzed under the two hypotheses of synchronization and non-synchronization, and its false alarm probability and detection probability were deduced. Then simulation on Direct-Sequence Spread-Spectrum (DSSS) system using MEAT was made whose result shows the Constant False Alarm Rate (CFAR) characteristic of MEAT and the improvement of detection probability of MEAT relative to traditional fixed threshold algorithm.

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Acquisition of PN code with adaptive threshold forDS/SScommunications

Cited by 17 publications

References 4 publications

Adaptive Hybrid Acquisition of PN Sequences Based on Automatic Multipath Cancellation in Frequency-Selective Rayleigh Fading Channels

Adaptive Hybrid Acquisition of PN Sequences Based on Automatic Multipath Cancellation in Frequency-Selective Rayleigh Fading Channels

Modulated laser radar decoding by inter symbol interference

Adaptive Acquisition Threshold Algorithm Based on Mean Energy

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