BER analysis using zero-forcing linear precoding scheme for massive MIMO under imperfect channel state information

ABSTRACT

In massive MIMO systems, inter-user interference has effect on the transmitted signals, so linear precoding techniques are employed for multiuser transmission channels to remove this inter-user interference. It is very complicated to design a suitable linear precoding technique having low computational complexity, which will give an excellent Bit Error Rate (BER) performance. In this paper, we analyse BER under imperfect Channel-State-Information (CSI) using Zero-Forcing (ZF) linear precoding scheme in the downlink, massive MIMO in Time-Division-Duplex (TDD) mode. We derive the closed-form expressions for BER that are obtained from the new expressions derived for Signal-Interference-Noise Ratio (SINR), and then analysis with different parameters using numerical and Monte Carlo simulated results is carried out in MATLAB under imperfect CSI. It was found that our theoretical analysis agrees well with the simulated results. In our analysis, BER was observed in most cases to be good when the number of Base Station (BS) antennas is large enough to accommodate the served users, but when the number of users grows up, the BER performance degrades depending on how many BS antennas are capable of handling the additional users. Also, increasing the downlink transmit power was found to improve the performance, but it is not an energy-efficient way for massive MIMO.     

改进的多用户OFDM系统子载波和比特分配算法

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Simplified transmitter design for MIMO systems with channel uncertainty

This article investigates transmitter design in Rayleigh fading multiple input multiple output (MIMO) channels with spatial correlation when there are channel uncertainties caused by a combined effect of channel estimation error and limited feedback. To overcome the high computational complexity of the optimal transmit power allocation, a simple and suboptimal allocation is proposed by exploiting the transmission constraint and differentiating a bound based on Jensen inequality on the channel capacity. The simulation results show that the mutual information corresponding to the proposed power allocation closely approaches the channel capacity corresponding to the optimal one and meanwhile the computational complexity is greatly reduced.     

空间相关莱斯衰落信道下基于部分信道信息的多用户预编码与调度算法

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多用户MIMO-OFDM系统低速率CSI反馈方法及信道容量分析

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一种新的MIMO无线通信系统链路自适应算法

提出并分析了一种适用于MIMO系统的新的链路自适应算法。通过接收端估计信噪比,并利用各种编码调制方式的特性,该算法在接收端采用递归的方法确定了每一个发射端子信道所采用的编码调制方式,使反向链路仅传输少量的控制信息,实现了链路的自适应。仿真结果表明,文章所提出的算法大大提高了MIMO系统的吞吐量,且可靠性也显著增加。     

基于CSI的三维联合参数估计算法

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基于过时信道信息的多用户中继网络性能分析

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Secrecy outage analysis in a hybrid cognitive relay network with energy harvesting

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新的谐波分析法和CSI多重化的研究

本文介绍一种适用于PWM和多重化等技术谐波分析的简便新方法,它可以用代数加法代替积分的方法。推导出各种直接耦合多重化方案通用的输出电流谐波幅值表达式;同时推导出变压器耦合的多重化(2～4)输出电流谐波幅值表达式,用此公式可得出消除特定谐波电流的变压器参数值。