RS码与LDPC码的联合迭代译码

针对RS码与LDPC码的串行级联结构,提出了一种基于自适应置信传播(ABP)的联合迭代译码方法.译码时,LDPC码置信传播译码器输出的软信息作为RS码ABP译码器的输入;经过一定迭代译码后,RS码译码器输出的软信息又作为LDPC译码器的输入.软输入软输出的RS译码器与LDPC译码器之间经过多次信息传递,译码性能有很大提高.码长中等的LDPC码采用这种级联方案,可以有效克服短环的影响,消除错误平层.仿真结果显示:AWGN信道下这种基于ABP的RS码与LDPC码的联合迭代译码方案可以获得约0.8 dB的增益.     

Optimum erasure threshold in Reed-Solomon coded differential 16 star-QAM modulation

The performance of a Reed-Solomon (RS) coded differential 16 star-QAM modulation scheme with a decision-directed estimation (DDE) technique as the channel-fading parameter in a frequency hopping (FH) system is simulated. The optimum erasure threshold for an RS decoder is obtained. It is shown that with the optimum erasure threshold a bit-error probability of 10/sup -5/ can be achieved at E/sub n//N/sub 0/=21.2 dB for using RS(63,31) and E/sub b//N/sub 0/=21.5 dB for RS(31,15).<>     

T-DMB手机电视的硬件实现方案

概述了T-DMB系统,描述了该系统的传输机制,给出了手机电视接收端的基带硬件框图并分析了信号的处理流程,最后介绍了两款T-DMB基带处理芯片.     

Real Time Traffic Information Service Using Terrestrial Digital Multimedia Broadcasting System

The major contribution of this paper is the implementation of real time traffic and traveler information service through the terrestrial digital multimedia broadcasting (T-DMB) system, which are known to be suitable for the mobile data services as well as audio and video services. The implemented system converts the Korean characteristic traffic information into the transport protocol expert group (TPEG) messages, and provides them to the T-DMB system. By testing the service with the TPEG message decoder implemented in the navigation system on PDA and laptop, it has turned out that it can be used as a highly efficient traffic information service system that could be adopted in Korea as well as in European countries     

一种新的基于DAB系统的改进方案

给出了一种提高DAB(Digital Audio Broadcasting)系统容量的方案,该方案能够达到基于DAB的T-DMB系统性能,但在系统容量上能比T-DMB提高30%.该方案在DAB系统应用层加入LDPC编码保护,形成LDPC级联DAB中的卷积码的编码结构,增强了对传输数据的保护,满足传输视频业务的误码要求,同时兼容DAB及基于DAB的改进系统.     

Iterative algebraic soft-decision list decoding of Reed-Solomon codes

In this paper, we present an iterative soft-decision decoding algorithm for Reed-Solomon (RS) codes offering both complexity and performance advantages over previously known decoding algorithms. Our algorithm is a list decoding algorithm which combines two powerful soft-decision decoding techniques which were previously regarded in the literature as competitive, namely, the Koetter-Vardy algebraic soft-decision decoding algorithm and belief-propagation based on adaptive parity-check matrices, recently proposed by Jiang and Narayanan. Building on the Jiang-Narayanan algorithm, we present a belief-propagation-based algorithm with a significant reduction in computational complexity. We introduce the concept of using a belief-propagation-based decoder to enhance the soft-input information prior to decoding with an algebraic soft-decision decoder. Our algorithm can also be viewed as an interpolation multiplicity assignment scheme for algebraic soft-decision decoding of RS codes.     

New Syndrome Check Error Estimation and Its Concatenated Coding

A low-complexity and high performance SCEE (Syndrome Check Error Estimation) decoding method for convolutional codes and its concatenated SCEE/RS (Reed–Solomon) coding scheme are proposed. First, we describe the operation of the decoding steps in the proposed algorithm. Then deterministic values on the decoding operation are derived when some combination of predecoder-reencoder is used. Computer simulation results show that the computational complexity of the proposed SCEE decoder is significantly reduced compared to that of conventional Viterbi decoder without degradation of the P_e performance. Also, simulation results of BER performance of the concatenated SCEE/Hard Decision Viterbi (HD-Viterbi) and SCEE/RS (Reed–Solomon) codes are presented.     

Design of the Channel Estimation Algorithm for Advanced Terrestrial DMB System

This paper describes a channel estimation algorithm for the advanced terrestrial digital multimedia broadcasting (T-DMB) transmission system which is fully backward compatible with the conventional T-DMB standard. The advanced T-DMB has enhanced features which provide higher transmission data rate for increasing program channel capacity and better multimedia A/V service quality than the conventional T-DMB system by adopting a hierarchical modulation and scalable audio/video CODEC. To support the higher data rate transmission for the advanced T-DMB, high performance channel estimation and equalization techniques should be adopted into the advanced T-DMB receivers. In this paper, we propose a new channel estimation technique for the Advanced T-DMB to compensate channel distortion under dynamic multipath environment.      

采用软/硬件协同设计的RS译码器

RS码在数字通信系统中得到了广泛的应用，本文在分析RS译码过程的原理基础上，提出了采用软／硬件协同设计的方法来实现RS译码器，并与目前已有的纯硬件方案做了性能对比。     

T-DMB系统容量分析与节目划分方法研究

T-DMB系统在1.536MHz带宽上能提供的最大数据速率是运营商极为关注的问题.通过对T-DMB系统的帧结构和编码方案分析,给出了T-DMB的系统容量,在结合T-DMB试验网实测数据基础上,提出了T-DMB系统承载节目的划分方法.     

一种高速自适应Reed-Solomon译码结构及其VLSI优化实现

该文给出了一种自适应Reed-Solomon(RS) 译码器结构。该结构可以自适应地处理长度变化的截短码编码数据块,适合于高速译码处理。该结构使译码处理不受数据块间隙长短的约束,既可以处理独立的编码数据块也可以处理连续发送的编码数据块。另外本译码器结构可以保证输出数据块间隔信息的完整性,满足无线通信和以太网中特殊业务的要求。本文还基于该结构对RS(255,239)译码器予以实现,该译码器经过Synopsys综合工具综合并用TSMC 0.18 CMOS工艺实现,测试结果验证了该译码器的自适应功能和译码正确性,其端口处理速率可达1.6Gb/s。     

高速RS(31,15)编译码器的FPGA实现

RS码由于具有优良的纠错能力而得到广泛应用。在军事通信中常以RS(31, 15)作为首选码。本文用一片现场可编程门阵列 (FPGA)芯片实现了高速RS(31, 15)编译码器。该编译码器具有体积小、性能稳定、工作速度高等优点。     

复杂环境下低信噪比WCDMA信号接收系统总体设计

根据区域内移动通信网信号接收的需求,提出了一种复杂环境下 低信噪比WCDMA移动通信信号接收系统的总体设计方案,针对关键环节小区搜索采用了差分 相干累积和RS译码判决等改进措施,提高了低信噪比WCDMA信号的处理性能。仿真和实验证 明了改进措施的有效性。     

Performance Analysis for LDPC-Coded Modulation in MIMO Multiple-Access Systems

We consider a low-density parity-check (LDPC)-coded modulation scheme in multi-input multi-output (MIMO) multiple-access systems. The receiver can be regarded as a serially concatenated iterative detection and decoding scheme, where the LDPC decoders perform the role of outer decoder and the multiuser demapper does that of the inner decoder. In this paper, we investigate the performance of the scheme with simulation results and bounds. Union upper bounds are derived, which can be used as additional means to evaluate the performance of the MIMO multiple-access system.     

Multi-symbol-sliced dynamically reconfigurable Reed-Solomon decoder design based on unified finite-field processing element

Reed-Solomon (RS) codes play an important role in providing the error correction and the data integrity in various communication/storage applications. For high-speed applications, most RS decoders are implemented as dedicated application-specified integrated circuits (ASICs) based on parallel architectures, which can deliver high data throughput rate. For lower-speed applications, the RS decoding operations are usually performed by using fine-grained processing elements (PE) controlled by a programmable digital signal processing (DSP) core, which provides high flexibility. In this paper, we propose a novel m-PE multi-symbol-sliced (MSS) RS datapath structure. The m-PE RS architecture is a highly scalable design and can be dynamically reconfigured at 1-PE, 2-PE,...,m/2-PE, and m-PE modes to deliver necessary data throughput rate. With the help of the gated-clock scheme to turn off the idle PEs, the proposed runtime configurable ASIC design provides good tradeoff between the data throughput rate and the power consumption. Hence, it can save energy to extend the battery life of the portable devices. We demonstrate a prototyping design using 4 PEs by using UMC 0.18-/spl mu/m CMOS technology. The design can be dynamically reconfigured to be operated at 1-PE, 2-PE, and 4-PE modes, with performance of 140 Mb/s at 18.91 mW, 280 Mb/s at 28.77 mW, and 560 Mb/s at 48.47 mW, respectively. Compared with existing RS designs, the proposed m-PE RS decoder has better normalized area/power efficiency than most DSP-type and ASIC-type RS designs. The reconfigurable feature makes our design a good candidate for the error control coding (ECC) unit of the storage system in power-aware portable devices.     

数字电视接收芯片中RS解码器的电路优化

RS码作为一种重要的信道编码方式在通讯领域中广泛应用,但是电路规模过大,结构过于复杂一直是该编码方式在应用上需要解决的问题。针对基于Euclidean算法的Reed-Solomon（RS）（204,188）解码器在HDTV接收芯片中的应用提出了几种优化电路结构,减小电路规模的方法。优化的主要思想是分时复用,优化后的电路可完全符合HDTV接收芯片的性能要求,减小了电路规模、复杂程度和降低了成本。     

Multistage decoding for internally bandwidth efficient coded Poisson fiber-optic CDMA communication systems

We consider the structure and performance of a multistage decoding scheme for an internally bandwidth efficient convolutionally coded Poisson fiber-optic code division multiple access (CDMA) communication system. The decoder is implemented electronically in several stages in which in each stage, the interfering users' coded bit decisions obtained in the previous stage is applied for computing the likelihood of the coded symbols of the desired user. The first stage is a soft-input Viterbi decoder for the internally coded scheme, in which the soft-input coded symbol likelihood values are computed by considering the multiuser interference as a noise signal. The likelihood of coded symbol computed in each stage is then entered into the convolutional decoder for the next bit decisions. The convolutional codes that are used for demonstrating the performance of the multistage decoder are super orthogonal codes (SOCs). We derive the bit error rates (BERs) of the proposed decoder for internally coded Poisson fiber-optic CDMA systems using optical orthogonal codes (OOCs) along with both ON-OFF keying (OOK) and binary pulse position modulation (BPPM) schemes. Our numerical results indicate that the proposed decoding scheme substantially outperforms the single-stage soft-input Viterbi decoder. We also derive the upper bound on the probability of error of a decoder for the known interference case, which is the ultimate performance of a multiuser decoder, and compare the result with that of the soft-input Viterbi decoder.     

A Higher Data-Rate T-DMB System Based on a Hierarchical A-DPSK Modulation

Hierarchical modulation can be effectively used to enhance terrestrial digital multimedia broadcasting (T-DMB) or digital audio broadcasting (DAB) systems in response to both the demand for higher data-rate and the need to be backward compatible with legacy receivers. QAM-type modulations are well-liked for hierarchical transmission but require coherent detection based on pilot symbol aided channel estimation. In the T-DMB or the DAB system using DQPSK modulation, however, any available pilot symbols except for the phase reference symbol do not exist. Differential amplitude phase shift keying (DAPSK) modulation is easily applied to the T-DMB system for a hierarchical modulation but may be susceptible to fast fading. As a good candidate for a hierarchical modulation of T-DMB to solve the above problems, we propose an amplitude differential phase shift keying (A-DPSK) modulation which is robust to fast fading by estimating only amplitude coefficients of the channel transfer function with the use of amplitude pilots. To raise the accuracy of channel estimation, we arrange the amplitude pilots in a come-type and introduce a noise-reduction scheme of averaging estimated channel coefficients. Simulation results show that the proposed A-DPSK provides a good choice for achieving a higher data-rate over other possible modulation schemes for advanced T-DMB or DAB systems.      

RS(4095,3935)码高速译码器的硬件实现

相对于符号取自GF(256)的RS码,现有文献对GF(4096)上RS码的性能和实现鲜有研究。将GF(4096)上若干不同码率的RS码进行了性能仿真对比。仿真结果表明,GF(4096)上的RS码具有很强的纠正随机和突发错误的能力。在误码率为10-6时,所仿真的3种不同码型的码字相对于BPSK调制分别取得了3.2 dB,3.7 dB和4 dB的编码增益。鉴于GF(4096)上RS码优良的性能,设计并实现了RS(4095,3935)码高速译码器。经过测试验证,该译码器具有设计的纠错能力,能稳定工作在150 MHz,其吞吐量达到1.8 Gb/s。     

广播网络融合中电子业务指南的研究

介绍了移动多媒体广播系统中电子业务指南的一般结构和功能,比较了T-DMB,DVB-H和BCAST中电子业务指南的异同.然后以T-DMB中承载DVB-H业务为例,提出了一种在移动广播系统融合过程中电子业务指南的生成、传输到检索的解决方案,最后通过Matlab仿真验证了其性能的优越性.