Hyoyoung Jung

Fast Signal Separation of 2-D Sparse Mixture via Approximate Message-Passing

Approximate message-passing (AMP) method is a simple and efficient framework for the linear inverse problems. In this letter, we propose a faster AMP to solve the L1-Split-Analysis for the 2-D sparsity separation, which is referred to as MixAMP. We develop the MixAMP based on the factor graphical modeling and the min-sum message-passing. Then, we examine MixAMP for two types of the sparsity separation: separation of the direct-and-group sparsity, and that of the direct-and-finite-difference sparsity. This case study shows that the MixAMP method offers computational advantages over the conventional first-order method, TFOCS.

On the Antijamming Performance of the NR-DCSK System

This paper investigates the antijamming performance of the NR-DCSK system. We consider practical jamming environments including broadband jamming (BBJ), partial-time jamming (PTJ), tone jamming (TJ), and sweep jamming (SWJ). We first analytically derived the bit error rates of the system under the BBJ and the PTJ. Our results show that the system performances under these two jamming environments are enhanced as increases, where is the parameter of the NR-DCSK modulation scheme denoting the number of times a chaotic sample is repeated. In addition, our results demonstrate that, for the PTJ, the optimal value of the jamming factor is close to zero when the jamming power is small; however, it increases and approaches one as the jamming power enlarges. We then investigate the performance of the system under the TJ and the SWJ via Monte-Carlo simulations. Our simulations show that single-tone jamming causes a more significant performance degradation than multitone jamming. Moreover, we point out that the system performance is significantly degraded when the starting frequency of the sweep jammer is close to the carrier frequency of the transmitted signals, the sweep bandwidth is small, and the sweep time is half of the transmitted bit duration.

One-dimensional piecewise-constant signal recovery via spike-and-slab approximate message-passing

This paper proposes a novel AMP solver for problems of 1-D piecewise-constant signals recovery under the compressed sensing framework. The proposed solver is named ssAMP-1D. The proposed solver is based on a factor graph consisting of two types of the factor nodes: one is for handling sparsity in finite differences Xi - Xi-1, and another is related to the measurement generation Y = HX + W. We construct the ssAMP-1D iteration from a sum-product rule based on the factor graph, where we use a spike-and-slab prior to encourage sparsity in the 1-D finite differences. We provide a summary of the algorithm construction, discussing the several aspects of ssAMP-1D through empirical comparison to the state-of-the-art solvers, GrAMPA, TV-AMP, EFLA and TV-CP.

Study on Tactical Target Tracking Performance Using Unscented Transform-based Filtering

ABSTRACT Tracking the tactical object is a fundamental affair in network-equipped modern warfare. Geodetic coordinate system based on longitude, latitude, and height is suitable to represent the location of tactical objects considering multi platform data fusion. The motion of tactical object described as a dynamic model requires an appropriate filtering to overcome the system and measurement noise in acquiring information from multiple sensors. This paper introduces the filter suitable for multi-sensor data fusion and tactical object tracking, particularly the unscented transform(UT) and its detail. The UT in Unscented Kalman Filter(UKF) uses a few samples to estimate nonlinear- propagated statistic parameters, and UT has better performance and complexity than the conventional linearization method. We show the effects of UT-based filtering via simulation considering practical tactical object tracking scenario.Key Words : Communication, Network Centric Operational Environment, Tracking, Geodetic Coordinate System, Kalman Filter, Unscented Transform

A relay selection scheme with interference cancellation at the receiver

In this work, we consider the relay selection (RS) method for an Amplify-and-Forward (AnF) relaying system in multi-cell environments. The selection scheme aims to maximize the instantaneous received signal-to-noise and interference ratio (SINR). We propose an idea of combining RS with interference cancellation (IC) at the receiver. Furthermore, we analyze the system outage probability performance with the proposed scheme. We use approximation approach to simplify the derivation of the probability distributed function (PDF) of the received SINR. The system outage probability bound is also given. Simulation results validate our analysis, and show that our scheme greatly improves the system outage probability as well as bit-error-rate (BER) performances.