• Title/Summary/Keyword: code tracking loop

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Relationship Between GPS Code and Carrier Tracking Performance for GPS Receivers (GPS 수신기에서 코드 추적 성능와 반송파 추적 성능의 관계)

  • 임영재;박찬식
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.56-56
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    • 2000
  • In this paper, the relationship between GPS code and carrier tracking performance is given. Through the error analysis and experiments, the performance of code tracking loop can be improved using narrow correlation. The performance of code tracking loop can be also improved if the better carrier tracking loop is used. On the other hand, the performance of carrier tracking loop is independent of that of code tracking loop.

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Design and Performance Analysis of a Noncoherent Code Tracking Loop for 3GPP MODEM (3GPP 모뎀용 동기 추적회로의 설계 및 성능 분석)

  • 양연실;박형래
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.12A
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    • pp.983-990
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    • 2003
  • In this paper, a noncoherent code tracking loop is designed for 3GPP MODEM and its performance is analyzed in terms of steady-state jitter variance and transient response characteristics. An analytical closed-form formula for steady-state jitter variance is Int derived for AWGN environments as a general function of a pulse-shaping filter, timing offset, signal-to-interference ratio, and loop bandwidth, together with the analysis on the transient response characteristic of a tracking loop. Based on the analysis, the code tracking loop with variable loop bandwidth that is efficient for full digital H/W implementation is designed and its performance is compared with that of the code tracking loop with fixed loop bandwidth, along with the verification by computer simulations.

Performance of PN Code Tracking Loop for a DS/CDMA System with Imperfect Power Control and Shadowing

  • Kim, Jin-Young
    • Proceedings of the IEEK Conference
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    • 2000.07a
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    • pp.501-504
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    • 2000
  • In this paper, performance of a pseudonoise (PN) code tracking loop is analyzed and simulated for a direct-sequence/code-division multiple access ( DS/CDMA) system with imperfect power control in a multipath fading channel. A noncoherent first-order delay-locked loop (DLL) is considered as a PN code tracking loop. Power control error is modeled as a log-normally distributed random variable. From the simulation results, it is shown that for smaller discriminator offset, tracking jitter performance is improved while MTLL performance is degraded. It is shown that large power control error and heavy shadowing substantially degrade the PN tracking performance. The analysis in this paper can be applicable to design of PN code tracking loop for a DS/CDMA system.

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Design of Combined GPS Signal Tracking Loop based on Kalman Filter (칼만필터 기반의 통합 GPS 수신기 추적루프 설계)

  • Song, Jong-Hwa;Jee, Gyu-In;Kim, Kwang-Hoon
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.9
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    • pp.939-947
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    • 2008
  • The GPS tracking loop consists of three parts in general: discriminator, loop filter and DCO (Digitally Controlled Oscillator). The loop filter is the main part of the tracking loop designed to ensure a good tracking performance. Generally, the loop filter is designed using classical PI(Proportional Integral) control. Although the carrier Doppler and code Doppler are generated by the same relative movement between the satellite and the user, often, the loop filters for each tracking loop are designed separately and independently. Sometimes, they are used in a combined manner such as carrier aided code tracking, FLL assisted PLL, etc. For better GPS signal tracking, we need to design the FLL/PLL/DLL altogether optimally. The purpose of this paper is to design a GPS receiver tracking loop based on the Kalman filter in a combined manner. Also, the proposed GPS receiver tracking loop is compared with a conventional tracking loop in terms of the transfer function and the DCO input. This paper shows that conventional tracking loop is equal to the Kalman filter based tracking loop.

Effect of Imperfect Power Control on Performance of a PN Code Tracking Loop for a DS/CDMA System

  • Kim, Jin-Young
    • Proceedings of the IEEK Conference
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    • 2000.06a
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    • pp.209-212
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    • 2000
  • In this paper, effect of imperfect power control on performance of a pseudonoise (PN) code tracking loop is analyzed and simulated for a direct-sequence/code-division multiple access (DS/CDMA) system. The multipath fading channel is modeled as a two-ray Rayleigh fading model. Power control error is modeled as a log-normally distributed random variable. The tracking performance of DLL (delay-locked-loop) is evaluated in terms of tracking jitter and mean-time-to-lose-lock (MTLL). From the simulation results, it is shown that the PN tracking performance is very sensitive to the power control error.

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THE EFFECT OF MASKED SIGNAL ON THE PERFORMANCE OF GNSS CODE TRACKING SYSTEM

  • Chang, Chung-Liang;Juang, Jyh-Ching
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.223-228
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    • 2006
  • The main purpose of this paper is to describe the code tracking performance of a non-coherent digital delay lock loop (DLL) or coherent DLL while tracking GNSS signal in the presence of signal masking. The masking effect is usually caused by buildings that obscure the signal in either a periodic or random manner. In some cases, ideal masking is used to remove random or periodic interference. Three types of the masked signal are considered - no masking, periodic masking, and random masking of the signal input to the receiver. The mean time to lose lock (MTLL) of the code tracking loop are evaluated, and some numerical result and simulation results are reported. Finally, the steadystate tracking errors on the performance of the tracking loop in interference environment are also presented.

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Design and Performance Analysis of Non-coherent Code Tracking Loops for HSDPA MODEM (HSDPA 모뎀용 동기추적회로의 설계 및 성능분석)

  • Yang, Yeon-Sil;Park, Hyung-Rae
    • Journal of Advanced Navigation Technology
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    • v.7 no.1
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    • pp.6-13
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    • 2003
  • In this paper, a non-coherent code tracking loop is designed for 3GPP HSDPA MODEM and its performance is analyzed in terms of steady-state jitter variance and transient response characteristics. Analytical closed-form formula for steady-state jitter variance is first derived for AWGN environments as a function of pulse-shaping filter, timing offset, signal-to-interference ratio, and loop bandwidth. Also obtained is the transient response characteristic of a tracking loop. Finally, the performance of the designed tracking loop is confirmed by computer simulations.

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Analysis and Comparison of Noncoherent Code Tracking Loops for DS-CDMA Systems (DS-CDMA 시스템을 위한 비동기식 동기 추적 회로의 성능 비교 분석)

  • Lee, Kyong Joon;Park, Hyung Rea;Chae, Soo Hoan
    • Journal of Advanced Navigation Technology
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    • v.1 no.1
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    • pp.70-80
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    • 1997
  • In this paper, the performances of two noncoherent code tracking loops, i. e., traditional code tracking loop(TCTL) and modified code tracking loop(MCTL) are analyzed and compared in a CDMA mobile environment. Closed-form formulas for steady-state jitter variance are derived analytically for the two schemes as a function of the pulse shaping filter, timing offset, signal-to-interference ratio, and loop bandwidth. The design issues of the loop filter are also addressed with emphasis on the second-order tracking loop. Finally, the degradation of BER performance due to timing errors is examined in a CDMA reverse link for IMT-2000 designed by ETRI.

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Performance of PN Code Synchronization with Extended Kalman Filter for a Direct-Sequence Spread-Spectrum System (직접시퀀스 확산대역 시스템을 위한 Extended Kalman Filter 기반의 PN 부호 동기화 성능)

  • Kim, Jin-Young;Yang, Jae-Soo
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.8 no.3
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    • pp.107-110
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    • 2009
  • In this paper, a PN code tracking loop with extended Kalman filter (EKF) is proposed for a direct-sequence spread-spectrum. EKF is used to estimate amplitude and delay in a multipath. fading channel. It is shown that tracking error performance is significantly improved by EKF compared with a conventional tracking loop.

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A FPGA implementation of a full-digital code acquisition/Tracking Loop for the CDMA direct-sequence spread-spectrum signals (대역 제한된 직접 시퀀스 CDMA 확산 대역 신호를 위한 전 디지탈 부호 획득 및 추적 루우프 FPGA 구현)

  • 김진천;박홍준;임형수;전경훈
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.5
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    • pp.165-171
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    • 1996
  • A noncoherent full-digital PN(pseudo noise) code acquisition/tracking loop has been presetned and implemented in FPGA for the CDMA band-limited direct-sequence spread-spectrum (DS-SS) signals. It employs a simple decimator to control of local PN code phase to lower the hardware cost, and a second order loop to enable the more accurate tracking. The proposed acquisition/tracking loop has been designed in RTL-level VHDL, synthesized into logic gates using the design analyzer of synopsys software, implemented in an ALTERA FPGA chip, and tested. The number of logic gates used in the implemented FPGA chip is around 7000. The functionality has been verified using a PC interface circuitry and a logic analyzer.

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