MIMO解码转发双向中继系统中的传输策略与中断概率分析

在多输入多输出(MIMO)解码转发(DF)双向中继系统中,分别设计了两种信道状态信息(CSI)情况下的系统传输策略,并推导了系统中断概率的闭合表达式.当已知完全CSI时,采用(最大比发送-最大比接收)MRT-MRC技术设计波束形成和合并向量;当未知完全CSI时,设计了基于有限反馈的传输策略,并采用随机向量量化和Grassmann两种码本进行数值仿真验证.仿真结论显示,所设计的双向中继传输策略的中断概率性能明显优于其他策略,所推导的闭合表达式能准确地表征系统中断概率性能.     

Nakagami-m衰落信道下固定增益中继系统性能分析

 在Nakagami-m衰落信道下,分析了两跳固定增益放大转发中继通信系统的性能.首先采用基于概率密度函数(PDF)的性能分析法推导了无协作分集时系统的中断概率和平均误符号率(ASER)的闭合表达式,然后采用基于矩生成函数(MGF)的方法推导了有协作分集时系统的中断概率和ASER表达式以及接收信噪比的n阶矩的闭合表达式.仿真结果显示,所推导的闭合表达式与数值仿真结果吻合良好,协作分集和较大的m值可提升系统性能,中继前后两跳的信道质量对系统性能的影响并不相同.     

Nakagami信道下MIMO解码转发中继系统的安全性能分析

在协同自适应解码转发中继系统中,该文针对Nakagami-m衰落信道,研究了基于多天线低复杂度的机会式传输策略的物理层安全性能。为充分利用天线分集增益提升系统安全性能,发送节点均采用发送天线选择策略,接收节点均采用最大比合并策略。推导了系统安全中断概率的闭合表达式,并进一步提供了渐近性能分析,得到了系统的安全分集阶数。仿真结果验证了理论分析的正确性,并揭示了各系统参数对机会式传输方案的安全性能的影响。结果表明,通过增加合法节点的天线数和增大合法信道的Nakagami衰落信道参数可显著提升系统安全性能。     

Nakagami-m信道下放大转发增量中继性能分析

针对放大转发(AF)协同分集网络在独立同分布(i.i.d.)平坦Nakagami-m衰落信道上的增量中继进行了端到端性能分析,给出了误码率(BER)的最小下界解析解以及信噪比(SNR)的中断概率。数值模拟显示分析结果与仿真结果完全匹配,同时,还针对不同信噪比检测门限条件下的系统误码率和中断概率的性能进行了评估和比较。     

解码转发双向无线携能全双工中继系统的能效研究

为了优化双向单中继全双工系统的能效,在中继节点引入无线携能技术,提出了一个双向无线携能全双工中继系统。该系统中继节点以功率分割方式进行能量收集,将收集的能量用于解码转发,在保证用户的服务质量需求下,将能效优化问题转化为能量消耗最小的优化问题,依据传输时隙以及各时隙信道容量需求进一步划分为两个子优化问题;然后,以能效最大化为目标,根据各时隙的信道容量求出传输功率,利用解码转发特性求出传输时间和功率分割因子,得出能效最优解。仿真表明,所提出的双向无线携能全双工中继系统的能效是单向无线携能全双工系统的1.3倍、双向全双工放大转发中继系统的2倍和双向全双工解码转发中继系统的2.6倍。      

同信道干扰条件下的多天线放大转发中继中断概率分析

该文研究了基于波束形成技术的双跳多输入多输出(MIMO)放大转发(AF)中继系统的中断概率,该系统在发射端、中继端和接收端都配置了多根天线。假设每条链路的发射端采用最大比传输(MRT)技术,接收端采用最大合并比(MRC)技术,该文得出了中继端受到同信道干扰时的信干噪比(SINR),推导了基于固定增益中继方案的中断概率(OP)闭合表达式。计算机仿真结果不仅验证了性能分析的有效性,而且还分析了关键参数对系统性能的影响以及配置多天线带来的好处。     

基于全双工的中继选择协作通信网络性能分析

文章针对全双工的解码转发机会中继选择协作通信网络的性能展开分析研究。分别在假设服从独立同分布的Nakagami-m和Rayleigh衰落链路下,推导出所提方案的中断概率闭式表达式,并通过仿真证实了其有效性。仿真分析表明,中断概率受一些关键参数影响,如残存自干扰强度,中继节点个数和链路平均信噪比,此外,还受衰落深度参数影响。     

Nakagami-m信道协作网络编码中断性能分析

无线网络编码是一项能极大提高无线网络流量的有用技术,而协作分集可以有效地克服无线衰落的影响。研究了Nakagami-m信道下协作网络编码系统中断性能,分析了不同协作策略下的互信息表达式,推导了协作网络编码中断概率闭式表达式,并对分析的结果进行了仿真。仿真结果显示,在高SNR和谱效率R〈4条件下,协作网络编码中断概率较分布式空时编码性能SNR增益有接近2 dB的提高,并且随分布参数m值的增大,协作网络编码中断概率性能逐步改善。     

能量收集全双工中继网络中的中继策略研究

本文针对双跳全双工多中继系统,研究了在中继节点能量受限情况下的中继选择方案。在该文中,中继工作方式为放大转发（Amplify-and-Forward, AF）,且中继通过收集源节点提供的能量来对源节点信息进行转发。整个通信过程分为两阶段,能量收集阶段与信息传输阶段,即采用的是时域分割方案。为了获得较好的性能与复杂度折中,本文分别研究了三种不同的中继选择策略,即最佳中继选择方案和两种次优中继选择方案。针对所提的三种方案,推导分析了其系统中断概率的理论值和下边界,以及系统的有效吞吐量。最后,利用蒙特卡洛仿真验证了理论分析的正确性,且仿真结果表明最佳中继选择方案的性能优于两种次优的中继选择方案,但其实现的复杂度高。      

Nakagami-m衰落下AF部分中继选择系统性能研究

在放大转发中继系统中,基于Nakagami-m衰落场景,借助概率密度函数、累积分布函数和矩生成函数性能分析法,推导了部分中继选择策略下协作分集系统采用不同调制方式的平均错误符号概率（ASEP）闭合表达式,给出了该系统协作分集下的分集阶数,并指出了在这一场景下影响ASEP性能的因素。仿真结果表明,所得的闭合表达式与数值仿真结果有良好的吻合性能,尤其在中高信噪比区域,所提方案具有很好的渐近性能,并通过仿真曲线进一步验证了与所提命题的一致性。     

Nakagami 信道下一种改进的DAF模型中断概率的研究

This paper proposes a modified decode and forward (DAF) protocol with a three node model, which contains two users and one destination. Each user can be either the source or the relay in different frames. We analyze the four cooperative cases in the first frame and run simulations to obtain the optimal power allocation coefficients in the second frame. The closed form expression of outage probability is derived over Nakagami m fading channels. Furthermore, we show that the proposed model has better performance than the non cooperation system and traditional DAF strategy based on the derived outage probability.     

Performance of Decode-and-Forward Cooperative Communications with Multiple Dual-Hop Relays over Nakagami-m Fading Channels

In this letter, we examine the symbol-error-rate (SER) performance of decode-and-forward (DF) cooperative communications. Our focus is on the scenario in which multiple dual-hop relays are employed and the channel environment is described by Nakagami-m fading. Cooperative diversity is observed from the derived error-rate expressions, and some insight into how channel conditions in the relay nodes affect the SER performance is obtained. In addition, with the knowledge of the partial channel state information (CSI) at the transmitting sides, we derive an optimal power allocation scheme to further enhance the SER performance. Simulation results are finally presented to demonstrate the correctness of our analysis and perception for the considered DF protocol.     

Cooperative Dual-Hop Relaying Systems with Beamforming over Nakagami-m Fading Channels

In this paper, we investigate the end-to-end performance of dual-hop relaying systems with beamforming over Nakagami-m fading channels. Our analysis considers semiblind (fixed-gain) relays with single antennas, and source and destination nodes equipped with multiple antennas. Closed-form expressions for the outage probability (OP), moment generating function (MGF), and generalized moments of the end-to-end signal-to-noise ratio (SNR) are derived. The proposed expressions apply to general operating scenarios with distinct Nakagamim fading parameters and average SNRs between the hops. The influence of the power imbalance, fading parameters, and antenna configurations on the overall system performance are analyzed and discussed through representative numerical examples. Furthermore, the exactness of our formulations is validated by means of Monte Carlo simulations.     

阴影Nakagami-m衰落信道条件下分布式天线系统中断分析

This paper presents an outage analysis of distributed antennas system (DAS) suffering from shadowed Nakagami-m fading environment where the desired signal also suffers from cochannel interference. The desired signal and interfering signal are subjected to path loss, multipath and shadowing fading. Based on Wilkinson's method, the signal to interference ratio (SIR) probability density function ( PDF) of fixed DAS is obtained. Some numerical results of outage probability with different parameters are analyzed. The analysis results can provide sufficient precision for evaluating the outage performance of DAS     

Outage Probability Analysis of Dual-Hop Decode-and-Forward Relaying Over Mixed Rayleigh and Generalized Gamma Fading Channels

In this letter, outage probability of dual-hop decode-and-forward (DF) relaying scheme is analyzed over mixed Rayleigh and generalized Gamma fading channels. Cooperation model considered in this work consists of a source, a relay and a destination. It is assumed that source-relay and relay-destination channels experience Rayleigh fading and generalized Gamma fading, respectively. Exact outage probability expression is derived and outage performance is illustrated for both direct transmission and DF relaying scheme.     

Multi-Antenna AF Two-Way Relaying Over Nakagami-m Fading Channels

We present the performance of multi-antenna selective combining amplify-and-forward (SC-AF) two-way relaying systems over independent and identically distributed (i.i.d) Nakagami- $m$ fading channels. The outage probability and symbol error probability of our relaying system are derived in closed-form. In order to get additional insights into the impact of system parameters, we consider the analysis of system at high signal-to-noise (SNR) regime. Through over high SNR analysis, we assume that the fading channels are independent and non-identically distributed (i.n.i.d). Also, there is no assumption on the fading parameter, $m$ . Moreover, some special cases of practical interest (e.g., Rayleigh fading channels, and single relay system) are also examined. Subsequently, we define an optimization problem using some approximations and then solve it analytically. Lastly, we present numerical simulations to check our analytical formulas.     

相关Nakagami衰落信道上DE-QPSK性能分析

推导m为整数的任意相关Nakagami-m衰落信道上采用最大比合并(MRC)分集接收和相干检测的差分编码四相相移键控(DE-QPSK)调制的平均误符号率(SER)精确表达式,并利用高斯Q函数指数形式的近似表达式推导相关Nakagami-m衰落信道上采用MRC分集接收的DE-QPSK调制的平均SER近似表达式。计算机仿真结果验证了精确理论分析的正确性和近似分析的准确性。