Codes Cross-Correlation Impact on S-curve Bias and Data-Pilot Code Pairs Optimization for CBOC Signals

The aim of this paper is to analyze the impact of spreading codes cross-correlation on code tracking performance, and to optimize the data-pilot code pairs of Galileo E1 Open Service (OS) Composite Binary Offset Carrier (CBOC) signals. The distortion of the discriminator function (i.e., S-curve), due to data and pilot spreading codes cross-correlation properties, is evaluated when only the data or pilot components of CBOC signals are tracked, considering the features of the modulation schemes. Analyses show that the S-curve bias also depends on the receiver configuration (e.g., the tracking algorithm and correlator spacing). In this paper, two methods are proposed to optimize the data-pilot code pairs of Galileo E1 OS. The optimization goal is to obtain minimum average S-curve biases when tracking only the pilot components of CBOC signals for the specific correlator spacing. The S-curve biases after optimization processes are analyzed and compared with the un-optimized results. It is shown that the optimized data-pilot code pairs could significantly mitigate the intra-channel (i.e., data and pilot) codes cross-correlation，and then improve the code tracking performance of CBOC signals

A simplicial algorithm for testing the integral properties of polytopes: A revision

Given an arbitrary polytope P in the n-dimensional Euclidean space R n , the question is to determine whether P contains an integral point or not. We propose a simplicial algorithm to answer this question based on a specifc integer labeling rule and a specific triangulation of R n . Starting from an arbitrary integral point ofR n , the algorithm terminates within a finite number of steps with either an integral point in P or proving there is no integral point inP. One prominent feature of the algorithm is that the structure of the algorithm is very simple and itcanbeeasily implemented on a computer. Moreover, the algorithm is computationally very simple, exible and stable.Linear Programming;operations research

Local Heat Transfer Measurements on a Rotating Flat Blade Model with a Single Film Hole

An experimental study was performed to measure the heat transfer coefficient distributions on a flat blade model under rotating operating conditions. A steady-state thermochromic liquid crystal technique was employed to measure the surface temperature, and all the signals from the rotating reference frame were collected by the telemetering instrument via a wireless connection. Both air and CO2 were used as coolant. Results show that the rotational effect has a significant influence on the heat transfer coefficient distributions. The profiles of hg/h0, which is the ratio of heat transfer coefficient with film cooling to that without film cooling, deflect towards the high-radius locations on both the pressure surface and suction surface as the rotation number (Rt) increases, and the deflective tendency is more evident on the suction surface. The variations in mainstream Reynolds number (ReD) and blowing ratio (M) present different distributions of hg/h0 on the pressure and suction surfaces, respectively. Furthermore, the coolant used for CO2 injection is prone to result in lower heat transfer coefficients.Peer reviewe