Entanglement-assisted codeword-stabilized quantum codes with imperfect ebits

안병규,신정환,허준 한국통신학회 2016 ICT Express Vol.2 No.2

In quantum communication systems, quantum error-correcting codes (QECCs) are known to exhibit improved performance with the use of error-free entanglement bits (ebits). In practical situations, ebits inevitably suffer from errors, and as a result, the error-correcting capability of the code is diminished. Previous studies have proposed two different schemes as a solution. One study uses only one QECC to correct errors on the receiver side (i.e., Bob) and sender side (i.e., Alice). The other uses different QECCs on each side. In this paper, we present a method to correct errors on both sides by using single nonadditive entanglement-assisted codeword stabilized quantum error-correcting code (EACWS QECC). We use the property that the number of effective error patterns decreases as much as the number of ebits. This property results in a greater number of logical codewords using the same number of physical qubits.

다중 입출력 다중 부호어 전송 환경을 위한 오류 검출 기반 순차적 간섭제거 기법

박상준 한국통신학회 2022 韓國通信學會論文誌 Vol.47 No.8

In this letter, a successive IC scheme based on the error detection is proposed for multiple codeword transmission in MIMO systems. Unlike the conventional successive IC scheme that performs the successive IC procedure of the last decoded codeword unconditionally, the proposed scheme performs the IC procedure only when the decoded codeword is detected in no errors. Therefore, the error propagation is minimized in the proposed scheme, which results in the performance enhancement. Simulation results show that the proposed scheme outperforms the conventional scheme for multiple-codeword transmissions in MIMO systems. 본 논문에서는 다중 입출력 시스템의 다중 부호어전송 환경에서 오류 검출 기반 순차적 간섭제거 기법을 제안한다. 부호어간의 복호 순서에 따라 순차적인간섭제거를 무조건적으로 진행하는 기존 순차적 간섭제거 기법과 달리, 제안 기법에서는 각 복호된 부호어가 오류가 없는 것으로 검출된 경우에만 간섭제거를 진행한다. 따라서 제안 기법은 간섭제거 과정에서의 오류 전파 최소화를 통해 오류 성능을 향상시킬수 있다. 모의실험 결과 제안 기법이 다중 입출력 시스템에서 기존 순차적 간섭제거 방식 대비 다중 부호어 전송 환경의 오류 성능을 크게 향상시킬 수 있음을 확인하였다.

Distributed arbitration scheme for on-chip CDMA bus with dynamic codeword assignment

Nikolic, Tatjana R.,Nikolic, Goran S.,Djordjevic, Goran Lj. Electronics and Telecommunications Research Instit 2021 ETRI Journal Vol.43 No.3

Several code-division multiple access (CDMA)-based interconnect schemes have been recently proposed as alternatives to the conventional time-division multiplexing bus in multicore systems-on-chip. CDMA systems with a dynamic assignment of spreading codewords are particularly attractive because of their potential for higher bandwidth efficiency compared with the systems in which the codewords are statically assigned to processing elements. In this paper, we propose a novel distributed arbitration scheme for dynamic CDMA-bus-based systems, which solves the complexity and scalability issues associated with commonly used centralized arbitration schemes. The proposed arbitration unit is decomposed into multiple simple arbitration elements, which are connected in a ring. The arbitration ring implements a token-passing algorithm, which both resolves destination conflicts and assigns the codewords to processing elements. Simulation results show that the throughput reduction in an optimally configured dynamic CDMA bus due to arbitration-related overheads does not exceed 5%.

${L_{1:1}}^\beta$(t) IN TERMS OF A GENERALIZED MEASURE OF ENTROPY

Hooda, D.S.,Ram, Anant 한국전산응용수학회 1998 Journal of applied mathematics & informatics Vol.5 No.1

In the present paper we define the codes which assign D-alphabet one-one codeword to each outcome of a random variable and the functions which represent possible transormations from one-one codes of size D to suitable codes. By using these functions we obtain lower bounds on the exponentiated mean codeword length for one-one codes in terms of the generalized entropy of order $\alpha$ and type $\beta$ and study the particular cases also.

Research on Per-cell Codebook based Channel Quantization for CoMP Transmission

( Zhirui Hu ),( Chunyan Feng ),( Tiankui Zhang ),( Qiubin Gao ),( Shaohui Sun ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.6

Coordinated multi-point (CoMP) transmission has been regarded as a potential technology for LTE-Advanced. In frequency division duplexing systems, channel quantization is applied for reporting channel state information (CSI). Considering the dynamic number of cooperation base stations (BSs), asymmetry feature of CoMP channels and high searching complexity, simply increasing the size of the codebook used in traditional multiple antenna systems to quantize the global CSI of CoMP systems directly is infeasible. Per-cell codebook based channel quantization to quantize local CSI for each BS separately is an effective method. In this paper, the theoretical upper bounds of system throughput are derived for two codeword selection schemes, independent codeword selection (ICS) and joint codeword selection (JCS), respectively. The feedback overhead and selection complexity of these two schemes are analyzed. In the simulation, the system throughput of ICS and JCS is compared. Both analysis and simulation results show that JCS has a better tradeoff between system throughput and feedback overhead. The ICS has obvious advantage in complexity, but it needs additional phase information (PI) feedback for obtaining the approximate system throughput with JCS. Under the same number of feedback bits constraint, allocating the number of bits for channel direction information (CDI) and PI quantization can increase the system throughput, but ICS is still inferior to JCS. Based on theoretical analysis and simulation results, some recommendations are given with regard to the application of each scheme respectively.

A CODING THEOREM ON GENERALIZED R-NORM ENTROPY

Hooda, D.S. 한국전산응용수학회 2001 The Korean journal of computational & applied math Vol.8 No.3

Recently, Hooda and Ram [7] have proposed and characterized a new generalized measure of R-norm entropy. In the present communication we have studied its application in coding theory. Various mean codeword lengths and their bounds have been defined and a coding theorem on lower and upper bounds of a generalized mean codeword length in term of the generalized R-norm entropy has been proved. AMS Mathematics Subject Classification : 94A17 and 94A24

Progressive Linear Precoder Design for Multiple Codewords MIMO ARQ Systems with ARQ Bundling Feedback

Zhengyu Zhang,Ling Qiu 한국통신학회 2012 Journal of communications and networks Vol.14 No.2

This work investigates the progressive linear precoder design for packet retransmissions in multi-input multi-output (MIMO) systems with multiple codewords and automatic repeat request (ARQ) bundling feedback. Assuming perfect channel state information, a novel progressive linear ARQ precoder is proposed in the perspective of minimizing the packet error rate. We devise the ARQ precoder by combining power loading and subchannel pairing between current retransmission and previous transmissions. Furthermore, we extend the design to the case that the channel estimation error exists. Numerical results show that the proposed scheme can improve the performance of MIMO ARQ systems significantly regardless of the channel estimation error.

Progressive Linear Precoder Design for Multiple Codewords MIMO ARQ Systems with ARQ Bundling Feedback

Zhang, Zhengyu,Qiu, Ling The Korea Institute of Information and Commucation 2012 Journal of communications and networks Vol.14 No.2

This work investigates the progressive linear precoder design for packet retransmissions in multi-input multi-output (MIMO) systems with multiple codewords and automatic repeat request (ARQ) bundling feedback. Assuming perfect channel state information, a novel progressive linear ARQ precoder is proposed in the perspective of minimizing the packet error rate. We devise the ARQ precoder by combining power loading and sub channel pairing between current retransmission and previous transmissions. Furthermore, we extend the design to the case that the channel estimation error exists. Numerical results show that the proposed scheme can improve the performance of MIMO ARQ systems significantly regardless of the channel estimation error.

밀결합 전송선 상에서 전력 저감을 위한 코드워드 생성 기법

임재호(Jae-Ho Lim),김덕민(Deok-Min Kim),김석윤(Seok-Yoon Kim) 大韓電子工學會 2011 電子工學會論文誌-SD (Semiconductor and devices) Vol.48 No.11

반도체 공정의 발달로 인해 칩의 집적도가 높아졌으며 연결선 사이의 간격 또한 좁아지게 되었다. 그로 인해 연결선 내에 존재하는 커패시턴스와 인덕턴스가 증가하게 되었고 특히 전역 연결선들에서는 자신의 그라운드 커패시턴스보다 인접한 다른 연결선과의 결합 커패시턴스가 더욱 커지는 경향을 보이게 되었다. 이러한 현상으로 인해 발생하는 유도성 결합과 용량성 결합은 인접한 연결선의 신호 간섭으로 심각한 문제를 야기할 수 있다. 본 논문에서는 추가적인 연결선을 이용하여 신호 무결성을 저해시키는 누화잡음을 제거하면서 입력 데이터의 확률을 고려하여 동적 전력 소모를 최소화하는 코드워드 생성 기법을 제안하였다. 제안한 기법의 성능평가를 위해 FastCap 및 FastHenry 프로그램과 HSPICE를 이용하여 실험한 결과 소모 전력에서 기존 기법보다 평균 15% 정도의 감소를 보임을 확인하였다. As semiconductor process rapidly developed the density of chips becomes higher and the space between adjacent lines narrows smaller. This trend increases the capacitance and inductance in interconnects and the coupling-capacitance of adjacent lines grows even bigger than the self-capacitance of themselves especially in global interconnects. Inductive and capacitive coupling observed in these phenomena may cause serious problems in signal integrity. This paper proposes a codeword generation technique using extra interconnect lines to reduce the crosstalk caused by inductive and capacitive coupling and to reduce dynamic power consumption considering probability of input data. To estimate the performance of the proposed technique the experimental results have been obtained using FastCap FastHenry and HSPICE and it has been shown that the power consumption using the proposed technique has yielded approximately 15% less than the results of the previous technique.

Hyperparameter Selection for APC-ECOC

석경하 한국데이터정보과학회 2008 한국데이터정보과학회지 Vol.19 No.4

The main object of this paper is to develop a leave-one-out(LOO) bound of all pairwise comparison error correcting output codes (APC-ECOC). To avoid using classifiers whose corresponding target values are 0 in APC-ECOC and requiring pilot estimates we developed a bound based on mean misclassification probability(MMP). It can be used to tune kernel hyperparameters. Our empirical experiment using kernel mean squared estimate(KMSE) as the binary classifier indicates that the bound leads to good estimates of kernel hyperparameters.