A filter algorithm for receiver tracking loops assisted by inertial information

2021 ◽  
pp. 1-11
Author(s):  
Zhifeng Han ◽  
Zheng Fang
Keyword(s):  
Integration Time ◽  
Frequency Error ◽  
Loop Filter ◽  
Signal Tracking ◽  
Phase Jitter ◽  
Loop Bandwidth ◽  
Tracking Ability ◽  
Negative Effect ◽  
Tracking Loops ◽  
Signal Environment

Abstract In traditional satellite navigation receivers, the parameters of tracking loop such as loop bandwidth and integration time are usually set in the design of the receivers according to different scenarios. The signal tracking performance is limited in traditional receivers. In addition, when the tracking ability of weak signals is improved by extending the integration time, negative effect of residual frequency error becomes more and more serious with extension of the integration time. To solve these problems, this paper presents out research on receiver tracking algorithms and proposes an optimised tracking algorithm with inertial information. The receiver loop filter is designed based on Kalman filter, reducing the phase jitter caused by thermal noise in the weak signal environment and improving the signal tracking sensitivity. To confirm the feasibility of the proposed algorithm, simulation tests are conducted.

INS-Assisted GNSS Signal Tracking Modeling and Assessment

2011 ◽  
Vol 271-273 ◽  
pp. 603-608
Author(s):  
Ping Ye ◽  
Xing Qun Zhan ◽  
Gang Du
Keyword(s):  
Inertial Sensor ◽  
Inertial Navigation ◽  
Phase Lock Loop ◽  
Signal Tracking ◽  
Gnss Receiver ◽  
Tracking Condition ◽  
Tracking Ability ◽  
Tracking Loops ◽  
Tracking Behavior ◽  
Gyro Drift

To improve the tracking performance of GNSS receiver in signal-attenuated environments, phase lock loop (PLL) and delay lock loop (DLL) assisted with Inertial Navigation System (INS) measurements are considered. Combining inertial navigation principles with signal processing, this paper proposes a simplified but efficient mathematical model of INS-assisted second-order tracking loops. Compared with unaided GNSS receiver, the tracking behavior of INS-assisted receiver is quantitatively analyzed, and the kind of INS suitable to guarantee the tracking condition is determined. The results indicate that an INS with 1 deg/h gyro drift is necessary to support PLL, and MEMS inertial sensor with 100 deg/h gyro drift is sufficient to aid DLL to keep favored tracking ability.

Improved Semi-Bit Differential Acquisition Method for Navigation Bit Sign Transition and Code Doppler Compensation in Weak Signal Environment

2020 ◽  
Vol 73 (4) ◽  
pp. 892-911 ◽  
Author(s):  
M. Nezhadshahbodaghi ◽  
M. R. Mosavi ◽  
N. Rahemi
Keyword(s):  
Signal To Noise Ratio ◽  
Integration Time ◽  
Data Sets ◽  
Weak Signal ◽  
Differential Acquisition ◽  
Global Positioning ◽  
Signal Environment ◽  
Correlation Techniques ◽  
Transition Issues ◽  
Acquisition Method

The presence of code Doppler and navigation bit sign transitions means that the acquisition of global positioning system (GPS) signals is difficult in weak signal environments where the output signal-to-noise ratio (SNR) is significantly reduced. Post-correlation techniques are typically utilised to solve these problems. Despite the advantages of these techniques, the post-correlation techniques suffer from problems caused by the code Doppler and the navigation bit sign transitions. We present an improved semi-bit differential acquisition method which can improve the code Doppler and the bit sign transition issues in the post-correlation techniques. In order to overcome the phenomenon of navigation bit sign transitions, the proposed method utilises the properties of the navigation bit. Since each navigation bit takes as long as 20 ms, there would be 10 ms correlations duration integration time between the received signal and the local coarse/acquisition (C/A) code in which the navigation bit sign transitions will not occur. Consequently, this problem can be cancelled by performing 10 ms correlations in even and odd units separately. Compensation of the code Doppler is also accomplished by shifting the code phase of the correlation results. To validate the performance of our suggested method, simulations are performed based on three data sets. The results show that the quantity of required input SNR to detect at least four satellites in the proposed method is − 48·3 dB, compared with − 20 dB and − 9 dB, respectively, in traditional differential and non-coherent methods.

scholarly journals A Ku-Band Fractional-N Frequency Synthesizer with Adaptive Loop Bandwidth Control

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 109
Author(s):  
Youming Zhang ◽  
Xusheng Tang ◽  
Zhennan Wei ◽  
Kaiye Bao ◽  
Nan Jiang
Keyword(s):  
Phase Noise ◽  
Frequency Synthesizer ◽  
Frequency Tuning ◽  
Cmos Technology ◽  
Voltage Controlled Oscillator ◽  
Loop Filter ◽  
Chip Area ◽  
Loop Bandwidth ◽  
Bandwidth Control ◽  
Ku Band

This paper presents a Ku-band fractional-N frequency synthesizer with adaptive loop bandwidth control (ALBC) to speed up the lock settling process and meanwhile ensure better phase noise and spur performance. The theoretical analysis and circuits implementation are discussed in detail. Other key modules of the frequency synthesizer such as broadband voltage-controlled oscillator (VCO) with auto frequency calibration (AFC) and programable frequency divider/charge pump/loop filter are designed for integrity and flexible configuration. The proposed frequency synthesizer is fabricated in 0.13 μm CMOS technology occupying 1.14 × 1.18 mm2 area including ESD/IOs and pads, and the area of the ALBC is only 55 × 76 μm2. The out frequency can cover from 11.37 GHz to 14.8 GHz with a frequency tuning range (FTR) of 26.2%. The phase noise is −112.5 dBc/Hz @ 1 MHz and −122.4 dBc/Hz @ 3 MHz at 13 GHz carrier frequency. Thanks to the proposed ALBC, the lock-time can be shortened by about 30% from about 36 μs to 24 μs. The chip area and power consumption of the proposed ALBC technology are slight, but the beneficial effect is significant.

scholarly journals Implementation and Analysis of Signal Tracking Loops for Software Defined GPS Receiver

2020 ◽  
Vol 8 (1) ◽  
pp. 9
Author(s):  
Aye Su Su Phyo ◽  
Hla Myo Tun ◽  
Atar Mon ◽  
Sao Hone Pha
Keyword(s):  
Gps Receiver ◽  
Signal Tracking ◽  
Tracking Loops

scholarly journals A 4-4.8GHz Adaptive Bandwidth, Adaptive Jitter Phase Locked Loop

2017 ◽  
Vol 7 (2) ◽  
pp. 1473-1477 ◽  
Author(s):  
H. E. Taheri
Keyword(s):  
Pump Current ◽  
Phase Locked Loop ◽  
Cmos Technology ◽  
Reference Frequency ◽  
Monitor Unit ◽  
Loop Filter ◽  
Loop Bandwidth ◽  
Simulation Results ◽  
Adaptive Bandwidth ◽  
Low Phase Noise

A low power, low phase noise adaptive bandwidth phase locked loop is presented in this paper. The proposed structure benefits from a novel lock status monitor unit (LSMU) that determines loop operation and loop bandwidth. The loop filter resistance and charge pump current are inversely proportional and bandwidth to reference frequency is maintained fixed. This structure is simulated in 0.18 μm CMOS technology and simulation results are presented.

A FLL-PLL Cooperative GNSS Weak Signal Tracking Framework

2014 ◽  
Vol 551 ◽  
pp. 470-477 ◽  
Author(s):  
Yang Liu ◽  
Yan Bo Zhu
Keyword(s):  
High Performance ◽  
Signal Attenuation ◽  
Signal Tracking ◽  
Navigation Solution ◽  
Delay Locked Loop ◽  
Dynamic Framework ◽  
Tracking Loops ◽  
Navigation Signals ◽  
Navigation Information ◽  
New Framework

Navigation signals should be steadily tracked to allow the extraction of navigation information, and support the calculation of navigation solution. Generally, extraction of navigation information is realized by GNSS tracking loops, which need to implement two critical operations: 1) tracking parameters should be precisely estimated in order to reliably decode the navigation message. 2) Successive tracking method of navigation information. This paper proposes a novel tracking framework using dynamic FLL assisting PLL strategy and a loop state detection monitor. The new framework extends traditional phase and delay locked loop (PLL/DLL) tracking framework, and contributions mainly lie in two parts. A dynamic framework for parameters adjustment is proposed to avoid tracking failure due to the change of environment, which is complemented in a FLL-PLL cooperative framework. Experimental results demonstrate the advantages of our algorithm compared with standard PLL/DLL framework. It is shown that the algorithm proposed is more suitable for tracking under signal attenuation situation, while maintaining high performance at the same time.

scholarly journals Performance and Evaluation of GNSS Receiver Vector Tracking Loop Based on Adaptive Cascade Filter

2021 ◽  
Vol 13 (8) ◽  
pp. 1477
Author(s):  
Haotian Yang ◽  
Bin Zhou ◽  
Lixin Wang ◽  
Qi Wei ◽  
Feng Ji ◽  
...  
Keyword(s):  
Covariance Matrix ◽  
Traditional Method ◽  
Phase Error ◽  
Frequency Error ◽  
Tracking Loop ◽  
Loop Filter ◽  
Noise Covariance Matrix ◽  
Vector Tracking ◽  
Noise Covariance ◽  
Local Code

In the scenario of high dynamics and low C/N0, the discriminator output of a GNSS tracking loop is noisy and nonlinear. The traditional method uses a fixed-gain loop filter for error estimation, which is prone to lose lock and causes inaccurate navigation and positioning. This paper proposes a cascaded adaptive vector tracking method based on the KF+EKF architecture through the GNSS Software defined receiver in the signal tracking module and the navigation solution module. The linear relationships between the pseudo-range error and the code phase error, the pseudo-range rate error and the carrier frequency error are obtained as the measurement, and the navigation filter estimation is performed. The signal C/N0 ratio and innovation sequence are used to adjust the measurement noise covariance matrix and the process noise covariance matrix, respectively. Then, the estimated error value is used to correct the navigation parameters and fed back to the local code/carrier NCO. The field vehicle test results show that, in the case of sufficient satellite signals, the positioning error of the proposed method has a slight advantage compared with the traditional method. When there is signal occlusion or interference, the traditional method cannot achieve accurate positioning. However, the proposed method can maintain the same accuracy for the positioning results.

Sign in / Sign up

Export Citation Format

Share Document