排序方式: 共有165条查询结果,搜索用时 15 毫秒
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通常,MIMO利用降低空时编码效率的方法,在复用增益与分集增益乘积一定的约束条件下,实现二者折衷;该文则从系统设计的角度,通过分析VBLAST,HARQ,STBC内在的联系,构造一种新型的混合重传方法,实现编码与HARQ二者平滑对接,在保持空时码满的复用增益前提条件下,以HARQ时延换取信噪比的提升,额外引入分集增益。同时,该文对信道相关性、重传时间与空间分集之间的重要关系作了系统深入的理论分析。仿真结果表明,所提方法对不同信道环境下的系统性能均有较大的提升。 相似文献
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该文在二发一收的空时分组码(STBC)单载波块传输系统中,提出一种空时和多径分集合并接收算法。通过基于STBC的单载波频域均衡(STBC-SC-FDE)算法得到对发送信号的估计,以此和信道状态信息(CSI)分离接收信号中的各多径分量,对各多径分量分别采用STBC合并,最后再将各多径分量的合并输出结果按照最大比(MRC)的方式进行合并,从而实现空时二维RAKE接收。该算法在较低的计算复杂度情况下,可以同时获得发射分集和多径分集,Monte Carlo仿真验证了该算法的性能。 相似文献
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Yung‐Ping Tu Wen‐Hsien Fang Yie‐Tarng Chen 《Wireless Communications and Mobile Computing》2012,12(9):767-781
This paper presents a new space–time two‐stage receiver with the assistance of soft information for the Alamouti space–time block code (STBC) and spatially multiplexing (SM) combined multiple‐input multiple‐output (MIMO) systems, which possess both the advantages of high diversity gain and high data rates to entail the next generation wireless communication systems. The first stage of the receiver, utilizing the inherent structure of the STBC, consists of a bank of soft generalized sidelobe canceller (GSC)‐based detectors, each for every STBC block, and intends to yield a more precise initial estimate of the transmitted symbols. In the second stage, the groupwise detection is conducted successively by using the matched filters (MFs) to simultaneously detect the two consecutive symbols in one STBC block with the removal of the soft interferences in between. Since the interferences have been faithfully reproduced and thoroughly annihilated, the new receiver can yield accurate symbol detection even with simple MFs. Moreover, some extreme cases regarding the soft information employed in the new receiver and its extension to the multiuser (MU) MIMO downlink are addressed as well. Conducted simulations show that the developed receiver, with modest computational load, can provide superior performance compared with pervious works, especially in the MU MIMO downlink. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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PHAM Van-bien 《中国邮电高校学报(英文版)》2011,18(6):44-50
Single-symbol maximum-likelihood(ML) decodable space-time block codes(SSDCs) can achieve a maximal symbol rate of 6/7 for multiple-input multiple-output(MIMO) communication system with five or six transmit antennas by using rate-efficient generalized coordinate interleaved orthogonal designs(RE-GCIODs).Unfortunately,there are many zero entries in the codeword matrix of RE-GCIODs.The zero entries result in high peak-to-average power ratio(PAPR) and also impose a severe constraint on hardware implementation.I... 相似文献
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In time division duplex (TDD) code division multiple access (CDMA) systems, chip‐synchronous transmission in the uplink is obtainable, thus leading to free multiple access interference in flat Rayleigh fading channels plus additive white Gaussian noise. This motivates us to develop a novel cooperative transmission strategy that allows single‐antenna devices to benefit from spatial diversity using orthogonal signature sequences. The proposed cooperation is applicable to many digital modulation methods and achieves the fullest diversity level, low implementation complexity, and a full data rate. Closed‐form bit‐error‐rate expressions were also derived and compared to simulation results in order to evaluate its validity. A variety of numerical results demonstrated the cooperation's superiority over single transmission under the same transmit power constraint. 相似文献
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DING Jie LIU Dan-pu WU Hua-ri .Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts Telecommunications Beijing China 《中国邮电高校学报(英文版)》2011,(4):31-38
In this paper,a cluster-based virtual multiple-input multiple-output(MIMO)transmission architecture is proposed for energy-constrained wireless sensor networks.In the proposed architecture,instead of using cluster members as cooperative nodes,multiple cluster heads cooperate to form virtual antenna array so that MIMO transmission can be implemented.According to the MIMO techniques used in this architecture,two different schemes,vertical Bell Laboratories layered space-time(V-BLAST)based cluster heads cooper... 相似文献
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