检索结果-内蒙古大学图书馆

Feedback-error-resistant and reduced feedback-rate orthogonal space-time block coding scheme employing single transmit antenna selection

引用

IET COMMUNICATIONS 2014年第13期8卷 2382-2392页

作者： Coskun, Ahmet Faruk Kucur, Oguz Sci & Technol Res Council Turkey Informat & Informat Secur Res Ctr Kocaeli Turkey Gebze Inst Technol Dept Elect Engn Kocaeli Turkey

A novel and generic transmit diversity scheme that employs combined single transmit antenna selection (TAS)/orthogonal space-time block coding (OSTBC) scheme with reduced feedback-rate and robust error performance in the presence of feedback errors (FEs) is introduced in this paper. Statistical expressions and performance metrics related to the post-processing signal-to-noise ratio of the proposed scheme are derived for Nakagami-m fading channels considering that the channel estimation process is error-free and the feedback information is delivered to the transmitter side with no delay. Exact expressions for outage probability and bit/symbol error rates of M-ary signals are presented to examine the system performance in the presence of FEs extensively. Also, the asymptotic analysis is provided to explore the asymptotic diversity order and the asymptotic coding gain of the proposed scheme that is compared with that of the conventional TAS/OSTBC scheme from different perspectives. The proposed scheme is shown to provide not only full-diversity order as the conventional scheme for perfect feedback case but also superior error performance in the presence of FEs. Moreover, the error performances of both schemes and the superiority of the modified scheme are examined by considering an error-correcting structure in the feedback link.

关键词： orthogonal codes space-time block codes transmitting antennas diversity reception Nakagami channels channel estimation error statistics error correction codes feedback-error-resistant scheme reduced feedback-rate orthogonal space-time block coding scheme single transmit antenna selection generic transmit diversity scheme TAS scheme OSTBC scheme robust error performance FE statistical expressions performance metrics post-processing signal-to-noise ratio Nakagami-m fading channels channel estimation process outage probability bit error rates M-ary signals BER symbol error rates asymptotic system order asymptotic coding gain feedback link error-correcting structure

来源：评论

学校读者我要写书评

暂无评论

Hybrid trellis coded modulation (HTCM) for visible light communications

引用

IET COMMUNICATIONS 2019年第1期13卷 85-92页

作者： Ndjiongue, Alain Richard Ferreira, Hendrik C. Univ Johannesburg Dept Elect & Elect Engn Sci Cnr Kingsway & Univ Rd Johannesburg South Africa

The radio frequency spectrum has become very congested and scarce. A response to this dilemma is the implementation of visible light communications (VLC) technology, which is enabled by the dramatic development of light emitting diodes (LEDs) and laser diodes (LDs). VLC has become the most popular emerging telecommunication technology. This is due to the interesting advantages that it provides, which include an unlicensed and large bandwidth, a high throughput capability and a low implementation cost. VLC needs a pivot network in medium and long distance transmissions. The amplify-and-forward scenario between the backbone network and VLC is cost-effective owing to its simplicity when compared to the decode-and-forward scenario. MPSK-CSK is a typical example of cascaded systems in AF scenario with VLC where the backbone channel utilises PSK to convey the message. In this paper, we investigate a forward error correction scheme for cascaded MPSK-CSK systems. A convolutional encoder is added to the MPSK-CSK scheme to construct the hybrid trellis coded modulation scheme. Selected 8HTCM systems using set partitioning are investigated and results for a Gaussian channel are presented. Numerical results reveal that 8HTCM achieves up to 2.129 dB of asymptotic coding gain when compared to the corresponding un-coded MPSK-CSK system.

关键词： light emitting diodes forward error correction trellis coded modulation phase shift keying free-space optical communication semiconductor lasers amplify and forward communication decode and forward communication convolutional codes radio spectrum management radio frequency spectrum VLC light emitting diodes laser diodes high-throughput capability low-implementation cost pivot network long-distance transmissions backbone network AF scenario forward error correction scheme selected 8HTCM systems visible light communication technology telecommunication technology HTCM backbone channel cascaded MPSK-CSK system M-aray phase-shift-keying-colour-shift-keying mapping medium-distance transmissions decode-and-forward scenario amplify-and-forward scenario convolutional encoder hybrid trellis coded modulation scheme set partitioning Gaussian channel asymptotic coding gain uncoded MPSK-CSK system

来源：评论

学校读者我要写书评

暂无评论

On asymptotically optimum rate 1/n convolutional codes for a given constraint length

引用

IEEE COMMUNICATIONS LETTERS 2001年第1期5卷 25-27页

作者： Papadimitriou, PD Georghiades, CN Texas A&M Univ Dept Elect Engn College Stn TX 77843 USA

The criterion used to find good convolutional codes has traditionally been the maximization of the free distance for a given constraint length and code rate. In this letter we approach convolutional code design from a different perspective. We assume no constraints in the rate of the code, and the only restriction is in the constraint length. That is, we assume we can utilize as much bandwidth as necessary but we are complexity-limited by the constraint length we can afford, The result are optimum codes for a given constraint length, which can find application, for example, in CDMA systems.

关键词： asymptotic coding gain CDMA convolutional codes low-rate codes

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：