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Cooperative diversity based on rotation code

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Journal of Central South University 2009年第2期16卷 280-284页

作者：熊雄葛建华李靖唐云帅 State Key Laboratory of Integrated Service Networks Xidian University

In order to obtain coding gain along with diversity gain,rotation code was applied to cooperative diversity employing decoded-and-forward cooperative *** from the same two symbols transmitted in conventional repetition-coded scheme,two different symbols were transmitted separately in two successive timeslots in the proposed rotation-coded cooperative *** this way,constellation spread in the available two-dimensional signal space rather than on a single-dimensional line in repetition-coded scheme,which was supposed to be responsible for the additional coding *** the proposed cooperative transmission model,upper bounds for the symbol-error-rate(SER)of cooperative diversity based on repetition code and rotation code were derived *** analytical and simulated results show that cooperative diversity based on rotation code can obtain an improved coding gain(by about 2 dB)than repetition-coded scheme without the expense of power or bandwidth.

关键词： cooperative diversity repetition code rotation code coding gain symbol-error-rate

Differential modulation based on space-time block codes

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Journal of Systems Engineering and Electronics 2004年第3期15卷 407-412页

作者：李正权胡光锐 DepartmentofElectronicsandCommunicationsYangzhouUniversity Yangzhou225009P.R.China DepartmentofElectronicsandInformationShanghaiJiaotongUniversity Shanghai200030P.R.China

A differential modulation scheme using space-time block codes is put forward. Compared with other schemes, our scheme has lower computational complexity and has a simpler decoder. In the case of three or four transmitter antennas, our scheme has a higher rate a higher coding gain and a lower bit error rate for a given rate. Then we made simulations for space-time block codes as well as group codes in the case of two, three, four and five transmit antennas. The simulations prove that using two transmit antennas, one receive antenna and code rate of 4 bits/s/Hz, the differential STBC method outperform the differential group codes method by 4 dB. Useing three, four and five transmit antennas, one receive antenna, and code rate of 3 bits/s/Hz are adopted, the differential STBC method outperform the differential group codes method by 5 dB, 6. 5 dB and 7 dB, respectively. In other words, the differential modulation scheme based on space-time block code is better than the corresponding differential modulation scheme

关键词： space-time block code coding gain differential modulation bit error rate.

OPTIMAL WAVELET FILTER DESIGN FOR REMOTE SENSING IMAGE COMPRESSION

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Journal of Electronics(China) 2007年第2期24卷 276-284页

作者： Yang Guoan Zheng Nanning Guo Shugang Institute of Artificial Intelligence and Robotics Xi＇an Jiaotong University Xi＇an 710049 China

A new approach for designing the Biorthogonal Wavelet Filter Bank (BWFB) for the purpose of image compression is presented in this letter. The approach is decomposed into two steps. First, an optimal filter bank is designed in theoretical sense based on Vaidyanathan’s coding gain criterion in SubBand coding (SBC) system. Then the above filter bank is optimized based on the criterion of Peak Signal-to-Noise Ratio (PSNR) in JPEG2000 image compression system, resulting in a BWFB in practical application sense. With the approach, a series of BWFB for a specific class of applications related to image compression, such as remote sensing images, can be fast designed. Here, new 5/3 BWFB and 9/7 BWFB are presented based on the above approach for the remote sensing image compression applications. Experiments show that the two filter banks are equally performed with respect to CDF 9/7 and LT 5/3 filter in JPEG2000 standard; at the same time, the coefficients and the lifting parameters of the lifting scheme are all rational, which bring the computational advantage, and the ease for VLSI implementation.

关键词： Wavelet filter Optimization coding gain Remote sensing image JPEG2000

Analysis and implementation of FEC in 10G-EPON

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Frontiers of Optoelectronics 2009年第4期2卷 384-388页

作者： Guozhou JIANG Deming LIU School of Optoelectronic Science and Engineering Huazhong University of Science and Technology

Forward error correction(FEC) may reduce the bit-error ratio(BER) and provide coding gain, so FEC is considered as a mandatory part in 10 Gbit/s Ethernet passive optical networks(10G-EPONs). First, the basic concepts of FEC and Reed-Solomon(RS) code are introduced in this paper. After a detailed description of the implementation of FEC in 10G-EPON, computed result shows that FEC based on RRS(255,223) can meet the need of 10G-EPON's high power budget. Therefore, FEC is the performance choice with high added value in 10GEPON.

关键词： forward error correction (FEC) 10 Gbit/s Ethernet passive optical network (10G-EPON) Reed-Solomon (RS) code bit-error ratio (BER) coding gain optical line terminal (OLT) optical network unit (ONU)

New Soft Output Viterbi Algorithm for Mobile Communication System

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Semiconductor Photonics and Technology 2006年第4期12卷 228-232页

作者： YI Qing-ming SHI Min Department of Electronic and Engineering Jinan University Guangzhou 510632 CHN

Soft output Viterbi algorithm （SOVA） is a turbo decoding algorithm that is suitable for hardware implementation. But its performance is not so good as maximum a posterior probability（MAP） algorithm. So it is very important to improve its performance. The non-correlation between minimum and maximum likelihood paths in SOVA is analyzed. The metric difference of both likelihood paths is used as iterative soft information, which is not the same as the traditional SOVA. The performance of the proposed SOVA is demonstrated by the simulations. For 1 024-bit frame size and 9 iterations with signal to noise ratio from 1 dB to 4 dB, the experimental results show that the new SOVA algorithm obtains about more 0. 4 dB and 0. 2 dB coding gains more than the traditional SOVA and Bi-SOVA algorithms at bit error rate（BER） of 1 × 10^-4 , while the latency is only half of the Bi-direction SOVA decoding.

关键词： SOVA algorithm Maximum likelihood path Minimum likelihood path coding gain

基于空时频编码的MB-OFDM超宽带系统研究

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基于空时频编码的MB-OFDM超宽带系统研究

作者：王宇北京交通大学

学位级别：硕士

近年来,超宽带(Ultra-Wide Band,UWB)无线通信技术因其在短距离传输通信中的高速率、低功耗、低散射等诸多优点倍受关注。多频带超宽带(Multi-BandOrthogonal Frequency Division Multiplexing UWB,MB-OFDM UWB)系统是近年来提出的新UW... 详细信息

近年来,超宽带(Ultra-Wide Band,UWB)无线通信技术因其在短距离传输通信中的高速率、低功耗、低散射等诸多优点倍受关注。多频带超宽带(Multi-BandOrthogonal Frequency Division Multiplexing UWB,MB-OFDM UWB)系统是近年来提出的新UWB方案。本文试图把MB-OFDM UWB技术、多天线输入多天线输出(Multiple-Input and Multiple-Output,MIMO)技术和空时编码技术联合起来,为日益增长的多媒体流量需求提供高速率、高质量、低功耗的通信。在MIMO-OFDM系统中,OFDM技术是将信号调制到多个不同的频率的载波上并行传输,本身就引入了频率分集,所以应用到MIMO-OFDM系统中的空时编码叫空时频编码(Space-Time-Frequency Code,STFC)。应用了空时频编码的多天线MB-OFDM UWB系统称为STFC MB-OFDM UWB系统。在本文中根据STFC MB-OFDM UWB系统与CO STBC(Complex OrthogonalSpace-Time Block Code)MIMO系统之间的相似性,来计算STFC MB-OFDM UWB系统的成对误码率(pair wise error probability,PEP),并得到STFC的编码方式与STBC的编码方式相同。我们得到的结论是分集增益与发射天线数目、接收天线数目和快速傅里叶变换的点数有关。文章还根据MB-OFDM UWB系统标准提出了一种分集的设计方案,可以获得更高的分集增益,从而提高误码率性能。在最后一章,本文针对STFC MB-OFDM UWB系统在同一范围短距离内多个设备间存在共信道干扰的问题,引入了波束成形技术。

关键词： MB-OFDM UWB STFC diversity gain coding gain beamforming