This letter shows the first carrier phase tracking and positioning results with Starlink's low earth orbit (LEO) satellite signals. An adaptive Kalman filter based algorithm for beat from unknown Starlink signals is proposed. Experimental show of six satellites a horizontal error 7.7 m known receiver altitude.

This letter shows the first acquisition, Doppler tracking, and positioning results with Starlink's low Earth orbit satellite signals. A generalized-likelihood-ratio-based test is proposed to acquire downlink Kalman-filter-based algorithm for tracking frequency from unknown Starlink signals developed. Experimental show of six satellites, achieving a horizontal error 10 m.

This letter unveils the unknown structure of Starlink low Earth orbit (LEO) satellites' orthogonal frequency division multiplexing (OFDM)-like reference signals (RSs). The spectrum Starlink's downlink is presented, and frame length estimated. A blind receiver proposed, which acquires via a sequential generalized likelihood ratio test multiple satellites, estimates their RSs respective Doppler, tracks carrier code phases. Experimental results are presented showing six tracked LEO three...

An opportunistic framework to navigate with differential carrier phase measurements from megaconstellation low Earth orbit (LEO) satellite signals is proposed. A computationally efficient integer ambiguity resolution algorithm proposed reduce the size of least-squares (ILS) problem, whose complexity grows exponentially number satellites. The Starlink constellation used as a specific example demonstrate efficacity algorithm, showing 60% reduction in ILS problem. joint probability density...

A Doppler tracking and beacon detection framework for blind opportunistic navigation (BON) with low Earth orbit (LEO) satellite signals is proposed. The BON cognitively deciphers partially known of opportunity (SOPs) exploits them purposes. When only the bandwidth length an Mary phase shift keying (MPSK) SOP available, enables acquisition terrestrial space-based SOPs in a fashion. computationally efficient algorithm presented to blindly detect estimate frequency. applied decipher C/A...

A receiver architecture is proposed to cognitively extract navigation observables from fifth generation (5G) new radio (NR) signals of opportunity. Unlike conventional opportunistic receivers which require knowledge the signal structure, particularly reference (RSs), cognitive (CON) requires only frame duration and carrier frequency signal. In 5G NR, some these RSs are transmitted on demand, limits existing frameworks <italic xmlns:mml="http://www.w3.org/1998/Math/MathML"...

This paper shows the first results of differential Doppler positioning with unknown low Earth orbit (LEO) Star-link satellite signals. To this end, a receiver capable acquiring and tracking frequency Starlink satellites is developed. A sequential method proposed to estimate number active their corresponding reference signals (RSs). The based on classic linear model, where it shown that model in so-called matched subspace detector. closed form probability false alarm presence estimation error...

A receiver architecture for cognitive sensing and navigation with orthogonal frequency division multiplexing (OFDM)-based systems is proposed. The proposed enables exploiting all the transmitted periodic beacons of 5G new radio (NR) Starlink low Earth orbit (LEO) signals to draw observables. Reference (RSs) modern OFDM-based systems, such as NR, contain both always-on on-demand components. These components can be unknown or known but subject change. To leverage purposes, RS should detected...

An algorithm for blind Doppler frequency estimation from orthogonal division multiplexing (OFDM) signals transmitted by low Earth orbit (LEO) satellites is developed. A method resolving the ambiguity in estimate also discussed. Two sets of experimental results are presented. The first demonstrates terrestrial fifth-generation (5G) on a mobile ground vehicle, achieving 14.5 Hz root mean-squared error (RMSE). second an unmanned aerial vehicle navigating using proposed approach with emulated 5G...

This paper demonstrates the first Doppler positioning-based results with Starlink low Earth orbit (LEO) satellites. A cognitive opportunistic framework is used to detect Starlink’s LEO satellite signals and track frequencies of each satellite. To this end, a generalized likelihood ratio (GLR)-based test developed estimate their corresponding beacons. chirp parameter estimator also proposed from unknown signals. Experimental are presented showing horizontal positioning error 10 m by tracking six

A blind opportunistic navigation (BON) framework is proposed. This deciphers partially known signals of opportunity (SOPs) in a cognitive fashion. BON enables acquisition and tracking terrestrial or space-based SOPs with minimal prior knowledge about their beacon signal. computationally efficient algorithm presented to blindly decode the estimate Doppler frequency. The applied decipher C/A pseudorandom noise (PRN) sequences from four GPS satellites. Experimental results are demonstrating...

Although zero-forcing (ZF) detection is well-known for its low computational complexity in multiple-input multiple-output (MIMO) communication systems, it suffers from significantly poor performance. The sphere decoder (SD) method, on the other hand, achieves maximum likelihood (ML) performance yet imposes a high complexity. We propose low-complexity scheme, concatenated with SD which verifies reliability of ZF equalized observations via some predefined regions and thresholds obtained by...

A receiver architecture for detection and tracking of Starlink orthogonal frequency division multiplexing (OFDM)-based signals is proposed. The proposed enables exploiting all the transmitted periodic beacons low Earth orbit (LEO) to draw carrier phase, code Doppler observables. reference (RSs) modern OFDM-based systems contain both always-on on-demand components. These components can be unknown subject dynamic transmission modes. Thanks a matched subspace-based algorithm, shown capable...

A receiver capable of estimating the Doppler and azimuth direction-of-arrival (DOA) Iridium NEXT low Earth orbit (LEO) signals opportunity (SOPs) is presented. The proposed operates in three stages: (i) Fast Fourier Transform (FFT)- based acquisition, (ii) Kalman filter (KF)-based tracking, (iii) Doppler-compensated MUltiple SIgnal Classification (MUSIC)-based algorithm for DOA tracking. Experimental results are presented demonstrating successful tracking frequency an LEO satellite,...

Tracking the Doppler frequency of a transmitter, where is being compensated at transmitter considered. A particular example this occurs Globalstar low Earth orbit (LEO) satellites. compensation takes place based on center each satellite beams. When compensated, measured by ground receiver different from real Doppler, which renders unusable for applications such as opportunistic navigation. This paper presents an approach to estimate true (i.e., uncompensated) subsequently used code and...

This paper studies the beamforming strategies of multiple-input multiple-output (MIMO) Starlink low Earth orbit (LEO) satellites. Applying a maximum likelihood (ML) estimation framework to signal-to-noise ratio (SNR), beam pattern satellites is calculated and switching schedule estimated. Experimental results with received signals from six LEO are presented demonstrating strategy.

A cognitive approach is proposed to detect unknown beacons of terrestrial signals opportunity (SOPs). Two scenarios are considered in the paper: (i) detection with integer constraints (IC) and (ii) no constraint (NIC). An example IC pseudo-noise (PN) sequences cellular code division multiple access (CDMA) signals. On other hand, reference (RSs) orthogonal frequency-division multiplexing (OFDM)-based systems can be as NIC. Matched subspace detectors for both scenarios, it shown experimentally...

A framework for differential Doppler navigation with Starlink low Earth orbit (LEO) space vehicle (SV) signals of opportunity is presented, and the framework's performance assessed. The assumes a rover (vehicle) navigating without global satellite system (GNSS) signals, through simultaneous tracking (STAN) approach. In STAN, aids its inertial (INS) measurements extracted from LEO SVs via an extended Kalman filter (EKF), simultaneously estimating vehicle's SVs' states. addition, stationary...

A computationally-efficient algorithm for blind Doppler frequency estimation from orthogonal division multiplexing (OFDM) signals is proposed. The objective of this to estimate the received low Earth orbit (LEO) satellite OFDM signals, which are planned massive future deployment. method resolving ambiguity in resulting discussed. To demonstrate efficacy proposed algorithm, and knowing that considered LEO constellations not fully deployed yet, experiments conducted with real terrestrial...

In this paper, we address the radar adaptive detection problem in case of multiple fluctuating targets with unknown parameters. The parameters are: number and location targets, amplitude phase received signals, Doppler frequency slowly target signal vectors rapid-fluctuating statistical characteristics noise clutter. We extract generalised likelihood ratio test (GLRT) Gaussian interference covariance matrix. Owing to high computational complexity these detectors when probable is large,...

To reduce the number of radio frequency (RF) chains in multiple input output (MIMO) systems, generalized spatial modulation (GSM) techniques have been proposed literature. In this paper, we propose a zero-forcing (ZF)-based detector, which performs an initial pruning search tree that will be considered as condition sphere decoding (SD) algorithm. The method significantly reduces computational complexity GSM systems while achieving near maximum likelihood (ML) performance. We analyze...

We present a diversity multiplexing tradeoff (DMT) optimal tree pruning sphere decoding algorithm which visits merely single branch of the search (SD) algorithm, while maintaining DMT optimality at high signal to noise ratio (SNR) regime. The is pruned via intersecting one dimensional spheres with hypersphere SD and radii are chosen guarantee optimality. In contrast conventional known have polynomial complexity SNR regime, we show that proposed method achieves by solely visiting simulation...