The effect of the frequency offset on the probability of miss in a packet modem using CFAR detection method (satellite communication)

1992 ◽  
Vol 40 (7) ◽  
pp. 1205-1211 ◽  
Author(s):  
M.R. Soleymani ◽  
H. Girard
Keyword(s):  
Satellite Communication ◽  
Detection Method ◽  
Frequency Offset ◽  
Cfar Detection

scholarly journals Adjacent Infrared Multitarget Detection Using Robust Background Estimation

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Sungho Kim ◽  
Kyung-Tae Kim
Keyword(s):  
False Alarm ◽  
False Alarm Rate ◽  
Target Detection ◽  
Detection Method ◽  
Detection Performance ◽  
Detection Methods ◽  
Constant False Alarm Rate ◽  
Cluttered Environments ◽  
Background Estimation ◽  
Cfar Detection

Small target detection is very important for infrared search and track (IRST) problems. Grouped targets are difficult to detect using the conventional constant false alarm rate (CFAR) detection method. In this study, a novel multitarget detection method was developed to identify adjacent or closely spaced small infrared targets. The neighboring targets decrease the signal-to-clutter ratio in hysteresis threshold-based constant false alarm rate (H-CFAR) detection, which leads to poor detection performance in cluttered environments. The proposed adjacent target rejection-based robust background estimation can reduce the effects of the neighboring targets and enhance the small multitarget detection performance in infrared images by increasing the signal-to-clutter ratio. The experimental results of the synthetic and real adjacent target sequences showed that the proposed method produces an upgraded detection rate with the same false alarm rate compared to the recent target detection methods (H-CFAR, Top-hat, and TDLMS).

scholarly journals A novel design of algorithm and framework for decentralized CFAR signal detection without prior information

2018 ◽  
Vol 189 ◽  
pp. 04006
Author(s):  
Nan Wang ◽  
Yunshan Xu ◽  
Haibao Xia ◽  
Jundi Wang
Keyword(s):  
Signal Detection ◽  
Prior Information ◽  
Detection Method ◽  
Detection Algorithm ◽  
Constant False Alarm Rate ◽  
Test Statistic ◽  
Fusion Algorithm ◽  
Cfar Detection ◽  
Novel Design ◽  
Fusion Detection

In this paper, a fusion detection algorithm that focuses on decentralized CFAR (Constant False Alarm Rate) signal detection problem without prior information is proposed. In the algorithm, the threshold and test statistic of the detection fusion algorithm derive from the conventional CFAR detection method. At last a framework for decentralized CFAR signal detection is designed corresponding to the fusion algorithm. Simulation results illustrate that an almost optimal detection performance is obtained by the proposed algorithm.

Doppler Frequency Offset for High Dynamic Signal with Low SNR

2014 ◽  
Vol 971-973 ◽  
pp. 1611-1615 ◽  
Author(s):  
Rui Zhao ◽  
Yan Wen Wang ◽  
Zhi Jie Wang
Keyword(s):  
Doppler Shift ◽  
Carrier Frequency ◽  
Satellite Communication ◽  
Carrier Frequency Offset ◽  
Frequency Offset ◽  
Rate Of Change ◽  
Low Snr ◽  
High Dynamic ◽  
Dynamic Signal ◽  
The Impact

In this paper, the impact on carrier capture of high dynamic and low SNR signal in satellite communication caused by the rate of change of the carrier frequency offset is analyzed. Firstly, the existing large carrier frequency offset estimate technology is described. Secondly, the rate of change of the carrier frequency offset impact on the carrier frequency offset is analyzed. Finally, the Doppler shift characteristics of Low SNR high dynamic signal and performance impact on the capture carrier are simulated by MATLAB. The results showed that the rate of change of Doppler shift will seriously affect the number of non-coherent accumulation times of the carrier frequency offset estimate.

scholarly journals LEO-Based Satellite Constellation for Moving Target Detection

2022 ◽  
Vol 14 (2) ◽  
pp. 403
Author(s):  
Chongdi Duan ◽  
Yu Li ◽  
Weiwei Wang ◽  
Jianguo Li
Keyword(s):  
Detection Method ◽  
Rapid Development ◽  
Contrast Ratio ◽  
Detection Threshold ◽  
Weighted Likelihood ◽  
Cfar Detection ◽  
Satellite Constellation ◽  
Satellite Platform ◽  
Leo Satellites ◽  
Fusion Detection

With the rapid development of cooperative detection technology, target fusion detection with regard of LEO satellites can be realized by means of their diverse observation configurations. However, the existing constant false alarm ratio (CFAR) detection research rarely involves the space-based target fusion detection theory. In this paper, a novel multi-source fusion detection method based on LEO satellites is presented. Firstly, the pre-compensation function is constructed by employing the range and Doppler history of the cell where the antenna beam center is pointed. As a result, not only is the Doppler band broadening problem caused by the high-speed movement of the satellite platform, but the Doppler frequency rate (DFR) offset issue resulted from different observation configurations are alleviated synchronously. Then, the theoretical upper and lower limits of DFR are designed to achieve the effective clutter suppression and the accurate target echo fusion. Finally, the CFAR detection threshold based on the exponential weighted likelihood ratio is derived, which effectively increases the contrast ratio between the target cell and other background cells, and thus to provide an effective multi-source fusion detection method for LEO-based satellite constellation. Simulation results verify the effectiveness of the proposed algorithm.

Frequency offset compensation for satellite communication system with CE-OFDM

2017 ◽  
Vol 14 (8) ◽  
pp. 93-104 ◽  
Author(s):  
Gaofeng Cui ◽  
Cheng Wang ◽  
Weidong Wang ◽  
Yinghai Zhang
Keyword(s):  
Communication System ◽  
Satellite Communication ◽  
Frequency Offset ◽  
Satellite Communication System ◽  
Offset Compensation

scholarly journals Incoherent Integration Detection Method of Airborne Phased Array Radar in a Multipath Environment

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yili Hu ◽  
Yongbo Zhao ◽  
Sheng Chen
Keyword(s):  
Phased Array ◽  
Detection Method ◽  
Detection Threshold ◽  
Constant False Alarm Rate ◽  
Detection Model ◽  
Cfar Detection ◽  
Phased Array Radar ◽  
Multipath Signal ◽  
Multipath Environment ◽  
Airborne Phased Array Radar

Airborne phased array radar (PAR) suffers from multipath problems when flying over a calm sea surface. The existence of a multipath phenomenon will cause the electromagnetic echo of the same target to be reflected back to the airborne PAR from two paths, namely, direct path (DP) and multipath. Compared with the ground-based radar, the target echo received by airborne PAR in the multipath environment has two important characteristics: one is that the DP signal and the multipath signal exist in different range bins, and the other is that the radar cross section (RCS) in the DP direction may be smaller than that in the multipath direction. Considering these two characteristics, this paper first proposes a target pairing algorithm for matching the DP range and multipath range of the same target in signal detection, and then, combined with the cell-averaging constant false alarm rate (CA-CFAR) detection model, an incoherent integration detection method for airborne PAR in the multipath environment is proposed. In the target pairing process, the geometric structure relationship of the airborne PAR model can be fully utilized. After a successful target pairing process, the energy of the multipath signal will be incoherently accumulated into the corresponding DP range bin, so as to improve the probability of DP range bin data passing the detection threshold. In essence, the proposed method makes full use of multipath energy to improve the detection capability of airborne PAR in the multipath environment. Finally, the detection probability of the proposed method is given, and the detection performance is analyzed.

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