A summary of the new GPS IIR-M and IIF modernization signals

The performance of the global navigation satellite system (GNSS) can be enhanced significantly by introducing the inter-satellite links (ISL) of a navigation constellation. In particular, the improvement of the position, velocity, and time accuracy, and the realization of autonomous functions require the ISL distance measurement data as the original input. For building a high-performance ISL, the ranging consistency between navigation satellites becomes a crucial problem to be addressed. Considering the frequency aging drift and the relativistic effect of the navigation satellite, the frequency and phase adjustment (FPA) instructions for the 10.23 MHz must be injected from the ground station to ensure the time synchronization of the navigation constellation. Moreover, the uncertainty of the initial phase each time the onboard clock equipment boots also results in a pseudo-range offset. In this Ref., we focus on the influence of the frequency and phase characteristics of the onboard clock equipment on the ranging consistency of the ISL and propose a phase compensation sensor design method for the phase offset. The simulation and experimental results show that the proposed method not only realized a phase compensation for the pseudo-range jitter, but, when the 1 PPS (1 pulse per second) falls in the 10.23 MHz skip area, also overcomes the problem of compensating the ambiguous phase by directly tracking the 10.23 MHz to ensure consistency in the ranging.

show abstract

“…According to Equations (14), (16), and (17),

σ_{t o t a l}

is approximately equal to 0.0696 ps. Set n equal to 4; as per Equation (12), the error of

p_{c o m p e n s a t e}

is 4

σ_{t o t a l}

, namely, 0.278 ps, that is considerably lesser than the accuracy of the 0.5 ns pseudo-code ranging [24] and a 10.23 MHz clock cycle.…”

Section: Phase Error Analysismentioning

confidence: 99%

Phase Compensation Sensor for Ranging Consistency in Inter-Satellite Links of Navigation Constellation

Zhang

Yang

Guo

et al. 2017

Sensors

View full text Add to dashboard Cite

show abstract

“…Interplex includes two kinds of techniques which are Interplex for Galileo and CASM (Coherent Adaptive Subcarrier Modulation) [5] (Coherent Adaptive Subcarrier Modulation) for GPS, and these two are equivalent in mathematics.…”

Section: A Interplexmentioning

confidence: 99%

Simulation analysis of constant-envelope multiplex algorithm for navigation signals in band-limited systems

Cai

Xie

Wang

2014

Proceedings of 2nd International Conference on Information Technology and Electronic Commerce

View full text Add to dashboard Cite

First of all, the three constant-envelope multiplex methods have been introduced: Interplex/CASM (Coherent Adaptive Subcarrier Modulation), Majority voting and POCET (Phase-Optimized Constant-Envelope Transmission). And then four signals multiplex has been simulated as an illustration using the three kinds of constant envelope multiplex techniques respectively. According to simulation analysis, the highest multiplex efficiency has reached -0.64dB when using POCET. And then the performance of three multiplex algorithms in band-limited systems has been simulated and analyzed. With the bandwidth limit, the multiple signal after constant-envelope multiplex cannot keep its envelope constant any more, which makes the multiple signal distort and brings crosstalk among sub signals. Therefore to study the constant-envelope multiplex techniques with bandwidth limit will become the important issue for the further research on navigation signal multiplex techniques.

show abstract

“…The Proposed GNSS Signal System. Prompted by the idea that data-free signal components are very useful in low Signal-to-Noise Ratio (SNR) environments arising from the modernised GPS signals (Holmes and Raghavan, 2004), in the proposed signal system, the navigation data and Pseudo Random Noise (PRN) code(s) (ranging code) are transmitted by respective modulation schemes. The PSK-R or BOC modulation is chosen for the transmission of PRN code(s) which is not modulated with data, and the navigation data is modulated by OFDM modulation.…”

Section: Introduction For Global Navigation Satellite Systems (Gnss)mentioning

confidence: 99%

Proposed OFDM Modulation for Future Generations of GNSS Signal System

Zherui

2016

J. Navigation

View full text Add to dashboard Cite

Modulation design has a significant effect on the accuracy of a navigation system. Two problems exist in current modulations for Global Navigation Satellite Systems (GNSS). One is the extremely low transmission rate of navigation messages. The other is the pseudorange error caused by multipath. To solve the restrictions, a novel GNSS signal system is proposed in this paper. In the new signal system, navigation messages are modulated by Orthogonal Frequency Division Multiplexing (OFDM) modulation for high transmission rate as well as excellent anti-multipath performance and conventional ranging code is still transmitted by Phase Shift Keying-Rectangular (PSK-R) or Binary Offset Carrier (BOC) modulation for precise ranging. Both the signal components supplement each other. Simulation results show that using the proposed GNSS signal system, stable and high transmission quality along with high transmission efficiency for navigation data are achieved. Also, the anti-multipath performance is significantly improved with less computational complexity. K E Y WO R D S 1. GNSS.2. Signal system. 3. OFDM.

show abstract

A summary of the new GPS IIR-M and IIF modernization signals

Cited by 15 publications

References 2 publications

Phase Compensation Sensor for Ranging Consistency in Inter-Satellite Links of Navigation Constellation

Phase Compensation Sensor for Ranging Consistency in Inter-Satellite Links of Navigation Constellation

Simulation analysis of constant-envelope multiplex algorithm for navigation signals in band-limited systems

Proposed OFDM Modulation for Future Generations of GNSS Signal System

Contact Info

Product

Resources

About