Yunhui Yi

Performance evaluation of acquisition algorithm for BOC-modulated signal against interference

In this paper, we analyze the characteristics of frequency spectrum and autocorrelation function of the signal in global navigation satellite system (GNSS) with binary offset carrier (BOC) modulation. We discuss the basic working processes of the traditional BOC acquisition algorithm and the one by using auto-correlation side-peak cancellation technique (ASPeCT). We also evaluate the effect of eliminating secondary peak and anti-interference performance of these two algorithms. We perform the simulation under Gaussian white noise and band-limited white noise. The simulation results show that the acquisition algorithm by ASPeCT has great advantage in the effect of side-peak cancellation and few advantages in anti-interference performance in Gaussian white noise and band-limited white noise environments.

Research and implementation of high-speed aviation bus

Since traditional aviation bus gradually can not meet the needs of modern military communication, migration of aviation bus towards high speed transmission is arousing wide concern. This paper purposes a method for improving throughput and transmission rate of the aviation bus while reserving legacy devices. In addition to cost, the logistics of implementing this upgrade to an aircraft can be prohibitive based on the amount of time required to retrofit an entire fleet. Moreover, the method combines OFDM (Orthogonal Frequency Division Multiplexing) modulation and aviation network has been evaluated over MIL-STD-1553 bus. The maximum rate can achieve 22Mbit/s. It shows a considerable performance improvement and meets the requirements of avionic high-rate communication.

Robust reconstruction under unknown SNR signal for analog-to-information conversion

A robust method to reconstruct the spectrum information for the analog-to-information converter (AIC) is developed. Current reconstruction algorithms require the prior knowledge or the estimation of noise level to set algorithmic parameters and stopping conditions. The proposed method requires no knowledge of noises or the acquired signal-to-noise ratio (SNR). We present a joined convex optimization model (JCO). Sampling at half of the Nyquist rate, the information of the origin signal can be rebuilt under the SNR as low as −10dB.

Study on Network Topology Visualization Algorithm and Implement Based on A Algorithm

This paper presents a network topology visualization algorithm based on A* algorithm. This algorithm is not only very universally applicable which can improve greatly the speed of operation and save the memory and meet the real-time requirement of network topology visualization, but also solve the problem of loop caused by single topology visualization algorithm, therefore, it’s preferably suitable for the research on complicated network topology.

Active Probe of Available Bandwidth: Analysis and Improvement

Active probe is the main method for Internet end-toend available bandwidth estimation. Based on the analysis of packet gap in active probing, an improved method to estimate available bandwidth is proposed, which is based on the concept of self-induced congestion. In this method, the transmission rates of probe packets are increased step by step and a new decision criteria, NWID (Normalized Weighted Increased Delay), is defined. Another idea is that sliding-window decision is adopted to obtain the available bandwidth in one measurement. Simulation and test results show that the measurement precision is improved with slightly adding probing overhead compared with pathChirp.

AB-cap: a fast approach to available bandwidth estimation

A new active measurement approach to Internet end-to-end available bandwidth estimation, AB-cap, is proposed, which is based on the concept of self-induced congestion. In this approach, the transmission rates of probing packets are increased step by step and a new decision criteria, NWID (Normalized Weighted Increased Delay), is defined. Another idea is that sliding-window decision is applied to determine the available bandwidth in one measurement. Simulation and test results show that the measurement precision is improved with slightly adding probing overhead compared with pathchirp.