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Phase Noise Pre-correction Scheme for SC-FDMA Signals in LTE-Uplink

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Chinese Journal of Electronics 2017年第3期26卷 634-639页

作者： XU Zijie ren guangliang ZHANG Yang State Key Laboratory of Integrated Service Networks Xidian University National Mobile Communications Research Laboratory Southeast University

This paper proposes a novel carrier Phase noise(PN)pre-correction scheme with an adaptive PN prediction algorithm for Single-carrier Frequency-division multiple-access(SC-FDMA)systems to alleviate degradation due to the *** proposed PN prediction algorithm is a modified polynomial fitting algorithm which is based on receding horizon *** parameters of the prediction model are optimized by using the algorithm on PN samples of the local oscillator signal in a training *** using the optimized prediction model parameters and the latest PN samples,we can predict future PN *** these predicted PN samples are put into our proposed PN pre-correction scheme and the SC-FDMA symbols at the transmitter are *** to the absence of the radio frequency delay device,the proposed scheme has a low hardware *** results show that our proposed scheme can greatly reduce the effect of the PN on the transmitted SC-FDMA signal.

关键词： Phase noise(PN) Single-carrier Frequency-division multiple access(SC-FDMA) Prediction algorithm

A novel initial ranging algorithm for OFDMA systems using smart antenna

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Science China(Information Sciences) 2014年第8期57卷 87-95页

作者： XIA YuJie ren guangliang State Key Laboratory of Integrated Service Networks Xidian University Luoyang Normal University

To improve the capacity of initial ranging(IR)users simultaneously accessing into network and enhance the performance of the IR,a novel IR algorithm is presented for the orthogonal frequency division multiple access systems with the smart *** beamforming weight vectors provided by the antenna array are introduced for the IR users,and the procedures of the multiuser parameter estimation and the interference cancellation are *** proposed method can improve the accuracy of the channel estimation of active paths and efficiently reduce the residual multiple access *** results show that the proposed method has a much better performance than the available successive multiuser detection and interference cancellation algorithm and accommodates more active ranging users simultaneously accessing into a cell.

关键词： orthogonal frequency division multiple access(OFDMA) initial ranging multiple access interference(MAI) beamforming smart antenna

SNR estimation algorithm based on the preamble for wireless OFDM systems

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Science in China(Series F) 2008年第7期51卷 965-974页

作者： ren guangliang CHANG YiLin ZHANG HuiNing State Key Laboratory of Integrated Service Networks Xidian University Xi'an 710071 China

Based on the analysis of the performance of Boumard＇s SNR method for wireless orthogonal frequency division multiplexing （OFDM） systems, a new estimation algorithm of the noise variance is proposed by only using the data samples of the two training symbols in the preamble, and the second order moment of these data samples is employed to estimate the signal power. The average SNR and the SNRs on the subchannels can all be estimated by the proposed algorithm, and its performance is independent of the channel＇s frequency selectivity. Simulation results show that the performance of the proposed method is highly improved and much better than that of Boumard＇s method.

关键词： orthogonal frequency division multiplexing (OFDM) SNR estimation preamble wireless channel

Lifetime maximization via joint channel and power assignment for incremental-relay multi-channel systems

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Science China(Information Sciences) 2019年第2期62卷 119-130页

作者： Lihua PANG Yang ZHANG Ruiyu HAN Kaiyang BAI guangliang ren JiANDong LI School of Information Engineering Xi'an University of Science and Technology State Key Laboratory of Integrated Service Networks Xidian University National Mobile Communications Research Laboratory Southeast University

A comprehensive resource optimization framework is designed for incremental amplify-andforward orthogonal frequency division multiplexing(AF-OFDM) relaying systems to maximize the network lifetime. Specifically, joint channel and power assignment, i.e., all degrees of freedom such as incremental policy, channel pairing, relay selection, and power allocation, are optimized with quality of service(QoS)constraints. The lifetime maximization problem is formulated as a mixed-integer nonlinear programming which at first glance seems mathematically intractable. However, a two-nested search loop, in which the outer loop varies the lifetime based on bisection criterion until finding the optimum while the inner loop attempts to derive the corresponding feasible solution set for that given lifetime by employing dual decomposition and subgradient techniques, is then presented to solve it. Numerical results are shown to verify the near-optimality and the effectiveness of our proposal.

关键词： lifetime maximization incremental relaying amplify-and-forward multi-channel systems resource optimization

Diversity–Multiplexing Tradeoff and Outage Performance for 2×2 Dual-Polarized Uncorrelated Rice MIMO Channels

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Communications and Network 2013年第3期5卷 319-326页

作者： Yanping Huang guangliang ren State Key Lab. of Integrated Services Networks Xidian University Xi’an China

In this paper, diversity-multiplexing tradeoff (DMT) curve for 2×2 Dual-Polarized uncorrelated Rice MIMO channels is studied. Exact expressions for statistic information of mutual information exponent are derived. Impacts of channel parameters such as signal to noise ratio (SNR), k-factor and cross polarization discrimination (XPD) on mutual information exponent are analyzed. Compared to conventional single-polarized (SP) Rice MIMO systems, a qualitatively different behavior is observed for DP Rice systems. The work in this paper, allows identifying quantitatively for which channels (k-factor) and SNR levels the use of dual polarization becomes beneficial. Gamma or lognormal distribution are used to describe mutual information component, and a theoretical formulation for finite-SNR DMT curve in 2×2 DP uncorrelated Rice channels is presented for the first time, which is valid in low and medium SNRs when multiplexing gain is larger than 0.75.

关键词： DMT curve Dual-Polarized Uncorrelated Rice Channel Mutual Information Exponent k-factor Outage Probablity Approximation

Multiuser Receiver Scheme with SIC for PUCCH in High Speed Train Environment

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Communications and Network 2013年第3期5卷 308-311页

作者： Wei Wang guangliang ren The State Key Laboratory of ISN Xidian University Xi’an China

A multiuser receiver scheme with successive interference cancellation (SIC) is proposed to suppress multiuser interference for physical uplink control channel (PUCCH) in high speed train (HST) environment. In the proposed algorithm, each user’s signal is detected iteratively in a descending order according to the signal strength at eNB. During each iteration, the strongest signal of all users’ is detected and regenerated, and then is subtracted from the composite signal before decoding the next user. Simulation results show that the proposed scheme obtains remarkable gains, e.g. 2 dB for PUCCH format 2 with 3 users in HST scenario 1. The improvement is more pronounced in the case of increasing number of users, e.g. 3.3 dB with 6 users.

关键词： PUCCH Successive Interference Cancellation High Speed Train Multiuser

MIMO-OFDMA系统中的一种新的初始测距方法

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西安电子科技大学学报 2013年第4期40卷 1-5,41页

作者：任光亮任晓娜西安电子科技大学综合业务网理论及关键技术国家重点实验室陕西西安710071

针对多输入多输出正交频分多址接入系统中基站多天线的特点,提出了一种利用波束成形的测距新方案.该方案首先利用基站多个接收天线上的接收信号矢量来计算用户测距码的波束成形矢量,再利用该矢量合并各天线的接收信号,抑制用户间的干扰... 详细信息

针对多输入多输出正交频分多址接入系统中基站多天线的特点,提出了一种利用波束成形的测距新方案.该方案首先利用基站多个接收天线上的接收信号矢量来计算用户测距码的波束成形矢量,再利用该矢量合并各天线的接收信号,抑制用户间的干扰,获得高质量的测距信号,来检测用户并估计用户的参数.计算机仿真结果表明,该方案有效降低了多用户接入系统时的漏检概率和虚警概率,参数估计的性能优于目前文献中的已有算法.

关键词：多输入多输出正交频分多址接入初始测距波束成形

Signal Detection Based on Walsh Transform for Spectrum Sensing

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Communications and Network 2013年第3期5卷 386-389页

作者： Guoxiang Yang guangliang ren Kun Wu State Key Lab. Of Integrated Services Networks Xidian University Xi’an China

Spectrum sensing is a key technology to improve spectrum efficiency. In this paper, we propose a novel signal detection method based on Walsh transform for spectrum sensing. The main idea behind is that the received signal is transformed into another domain by Walsh transform and the test statistic is obtained by exploiting the feature of the useful signal in the new domain. The new method can perform well at low signal-to-noise rate (SNR). Simulation results show that the proposed method has better performance than the spectral feature detection based on power spectrum.

关键词： Cognitive Radio Walsh Transformation Feature Detector Low SNR

波束成形辅助的连续干扰消除OFDMA初始测距算法

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西安电子科技大学学报 2013年第4期40卷 79-84,154页

作者：夏玉杰任光亮西安电子科技大学综合业务网理论及关键技术国家重点实验室陕西西安710071 洛阳师范学院物理与电子信息学院河南洛阳471022

针对影响正交频分多址(OFDMA)网络中初始测距系统性能的多径信道频率选择性和多用户接入干扰(MAI)的问题,利用新一代无线通信系统基站的智能天线,提出一种新的波束成形辅助的多用户连续干扰消除初始测距算法.所提算法通过一组波束成形矢... 详细信息

针对影响正交频分多址(OFDMA)网络中初始测距系统性能的多径信道频率选择性和多用户接入干扰(MAI)的问题,利用新一代无线通信系统基站的智能天线,提出一种新的波束成形辅助的多用户连续干扰消除初始测距算法.所提算法通过一组波束成形矢量,从空间上将一个小区分成若干个小的测距区域,抑制了其他小区域中测距用户的干扰,提高了每个小区域中测距用户的信噪干扰比.在每个小测距区域中,采用简化的连续干扰消除方法和自适应门限进行多用户测距码检测和时偏估计.计算机仿真结果表明,与已有连续多用户检测干扰抵消(SMUD)算法相比,在15个测距用户和SNR为-6dB时,所提出的算法比SMUD算法的正确检测概率提高了80%.

关键词：正交频分多址(OFDMA) 波束成形初始测距连续干扰消除