Jun Heo

Efficient information reconciliation with turbo codes over the quantum channel

In this paper, we introduce a new error correcting protocol in quantum key distribution. With this method, leakage information during the information reconciliation is reduced and a longer key can be obtained. In order to correct errors on the quantum key, we apply the turbo codes and transmit the parity information over the quantum channel. We compare loss rate of the proposed information reconciliation method with a conventional scheme in quantum key distribution.

An Efficient Decoding Scheme for Improved Throughput in Three Dimensional Turbo Product Codes based on Single Parity Code

This study proposes an effective decoding method that can be used when the existing two dimensional Turbo Product code (TPC) with extended Hamming code is expanded to three dimensional TPC by applying Single Parity code (SPC). In the multidimensional TPC, the SPC is mainly used for increasing the code rate of the axis with short code length. However, the SPC is unable to correct errors, and therefore, its application only is unlikely to improve the performance of the three dimensional TPC. Moreover, its expanded dimensions decrease the throughput. To solve this problem, three types of decoding schemes are suggested. The first scheme is applied to form of mixed iterative decoding scheme that serial and parallel decoding method are used together. Secondly, Normalized Min-Sum (NMS) algorithm is used in axis with shortest code length. Finally, Partial sorting networks reduces clock consumption of least reliable values selection in Chase-Pyndiah algorithm.

Performance analysis of opportunistic coded cooperation in Rayleigh fading channels

This paper is on the bit error probability (BEP) of opportunistic decode-and-forward (DF) relaying with coded cooperation, where cooperation diversity is achieved through both channel coding method and spatial diversity of relay selection. Codewords are partitioned into two parts which are sources data and parity, these are transmitted from sources antenna or selected relays antenna. In this scheme, relay selection is performed in relay subset which consists of relay nodes that successfully decode sources data and parity is transmitted from selected relay nodes antenna. If all the relay nodes are fail to decode sources data the source transmits its parity to the destination instead of the relay node. We derive the closed-form of bounds on BEP of this scheme based on Viterbis upper bound. These results illustrate diversity gain with multiple relay nodes in coded cooperation and present the performance analysis of proposed scheme in numerical results.