Jung-pil Yu

High Order Modulation in Faster-Than-Nyquist Signaling Communication Systems

In this paper we investigate the highly bandwidth-efficient Faster-than-Nyquist (FTN) signaling scheme under high order modulations. The FTN system is an emerging technology which has drawn attention in the contemporary spectrum-saving communication environment. Since FTN traditionally achieves high bandwidth efficiency through increased baud-rate, binary modulation is assumed in most research of FTN. The contribution of this paper lies in the extension into high order modulations and its assessment. This enables the communication systems to achieve higher data rates for the same bandwidth and receiver complexity than binary Nyquist signaling systems. Moreover, it is shown that an additional efficiency gain can be achieved by replacing the LDPC codes from the DVB-S2 standard by new optimized quasi-cyclic (QC) LDPC codes whose parameters are matched with FTN signaling.

Interleaver design for turbo codes from convergence analysis

In this letter, we present an analysis tool for the convergence of a turbo decoder using the min-sum algorithm. First of all, we classify cycles on a turbo code factor graph. We define and develop a quantity which characterizes the trellis convergence and a probability of a message round on a cycle. Our analysis is then applied to an interleaver design for a turbo decoder using the min-sum algorithm. Since the probability of a message round is closely related to the convergence property, the constructed interleaver optimizes the convergence property. The performance is compared with several referential interleavers.

Interleaver design for serial concatenated convolutional codes

In this paper, we present an interleaver design method for SCCC. Our design criterion is to minimize the message-round probability in the SCCC graph which is specially well suited for SCCC. The message-round probability characterizes the message flow in the SCCC graph. By minimizing it, we can get a large interleaving gain. The simulation results confirm our approach.

Software-defined DTV platform

Since the first appearance of the digital TV standard in mid-1990, the number of digital Television standard increases up to a dozen until now. In this circumstance, it is no wonder for a modern DTV to support several standards simultaneously. For example, almost all DTVs sold in Europe support DVB-T standard as well as DVB-C standard. From the engineering standpoints, this multi-standard DTV is a good candidate for software-defined radio concept which allows the DTV to adapt to various standards by only affecting the software modules. In this paper, a software-defined DTV platform which has been developed and successfully tested in SAMSUNG electronics R&D center is described. This platform is equipped with a reconfigurable processor and common hardware. As an example, the 2nd generation terrestrial broadcasting, namely DVB-T2 is successfully incorporated into the platform of FPGA (field-programmable gate arrays).

Modeling Burst Error Properties in Turbocodes: Application to DVB-RCS

One of the most studied fields in coding are turbocodes. Everyone knows the good performance of turbocodes in terms of bit error rate (BER). However, very little is known about the error distribution at its output. The knowledge of these error statistics is very useful to design the packet size or the overhead location. Are these errors randomly distributed within the packet, or do they follow a particular law? People working at physical layer level need more information about the error distribution at the output of the turbodecoder. This paper gives some statistics of the errors after turbodecoding. A model describing this error behavior is presented and validated through computer simulations for the turbocode used in the interaction channel for Digital Video Broadcasting by Satellite (DVB-RCS standard).