期刊文献+
共找到19篇文章
< 1 >
每页显示 20 50 100
认知无线电中一种基于干扰温度的功率控制算法
1
作者 胡智伦 何世彪 张新春 《现代电子技术》 2010年第1期50-54,共5页
基于干扰温度模型,应将认知无线电网络中认知用户与主用户共享频谱时应满足各自的用户服务质量(QoS)问题转化为有约束的非线性功率控制优化问题。运用迭代算法和拉格朗日相关理论探讨出一种近似最优的功率分配算法。理论分析和仿真表明... 基于干扰温度模型,应将认知无线电网络中认知用户与主用户共享频谱时应满足各自的用户服务质量(QoS)问题转化为有约束的非线性功率控制优化问题。运用迭代算法和拉格朗日相关理论探讨出一种近似最优的功率分配算法。理论分析和仿真表明,该算法既能满足主用户的干扰温度容限,同时又能使认知用户获得很好的信噪干扰比,增大系统的吞吐量。 展开更多
关键词 认知无线电 干扰温度 功率控制 信噪干扰比
下载PDF
多输入多输出广播信道下基于有限反馈的最大输出SINR线性天线合并算法 被引量:1
2
作者 吕磊 张忠培 《电子与信息学报》 EI CSCD 北大核心 2014年第6期1460-1464,共5页
在基于有限反馈的多天线MIMO广播信道下,由信道量化误差带来的多用户干扰(MUI)会严重地降低系统性能。天线合并技术可以利用多接收天线提供的多维自由度有效地改善系统性能。该文针对最近被证明为最优的反馈资源分配策略,设计了一种线... 在基于有限反馈的多天线MIMO广播信道下,由信道量化误差带来的多用户干扰(MUI)会严重地降低系统性能。天线合并技术可以利用多接收天线提供的多维自由度有效地改善系统性能。该文针对最近被证明为最优的反馈资源分配策略,设计了一种线性天线合并算法,该算法在提高反馈精度和增强期望信号增益之间做出合理的折中,可使期望输出信噪干扰比(SINR)最大化。首先导出了线性合并器期望输出SINR的下界闭合表达式,然后利用这个表达式得到使输出SINR最大化的线性合并器。仿真表明该线性合并算法与已有算法相比具有明显的性能提升。 展开更多
关键词 多输入多输出 线性天线合并器 最大信噪干扰比 迫零波束形成 有限反馈
下载PDF
基于物理干扰模型的WSN拓扑控制算法 被引量:5
3
作者 李玉民 禹继国 万胜利 《计算机工程》 CAS CSCD 2014年第5期89-93,共5页
拓扑控制是无线传感器网络研究中的重要问题。现有的大多数关于拓扑控制的工作集中于如何降低能耗,但是没有考虑干扰带来的影响。针对网络容量的最大化问题,提出一种在信号干扰信噪比模型下的拓扑控制算法PLTCA。该算法无需任何节点... 拓扑控制是无线传感器网络研究中的重要问题。现有的大多数关于拓扑控制的工作集中于如何降低能耗,但是没有考虑干扰带来的影响。针对网络容量的最大化问题,提出一种在信号干扰信噪比模型下的拓扑控制算法PLTCA。该算法无需任何节点的位置信息,通过计算3跳以内的前向和后向列表来构建拓扑。在PLTCA算法中,采用功率控制技术,节点通过改变发射功率或者发射方向选择自己的邻居节点,从而控制网络拓扑结构。通过理论分析对算法的连通性进行论证。仿真结果表明,PLTCA算法在保证网络连通性的基础上,减少了网络总体的能量损耗,与MaxSR算法相比,节点的平均链路能量损耗减少10%~20%。 展开更多
关键词 无线自组网 干扰 无线传感器网络 拓扑控制 能量损耗 连通性
下载PDF
高速公路收费CCTV系统图像干扰处理方法
4
作者 林祥华 《中国交通信息产业》 2003年第2期43-44,共2页
高速公路收费CCTV系统即高速公路收费闭路电视监控,是随着我国高速公路机电工程的应用和发展逐步形成的,是有中国特色的收费系统管理手段的体现.它承担着收费监视、收费稽查和异常事件处理等重要任务.随着国内联网收费的兴起,高速公路收... 高速公路收费CCTV系统即高速公路收费闭路电视监控,是随着我国高速公路机电工程的应用和发展逐步形成的,是有中国特色的收费系统管理手段的体现.它承担着收费监视、收费稽查和异常事件处理等重要任务.随着国内联网收费的兴起,高速公路收费CCTV系统也日益趋向复杂化、多级化.从目前情况来看,一些省份的收费CCTV系统的结构层次较多,如四川省的成雅高速公路收费CCTV系统就划分为四级网络结构,即划分为四个子系统:收费站CCTV子系统、收费分中心CCTV子系统、收费中心CCTV子系统和清分中心CCTV子系统.收费图像在经过多级传输后会产生不同的干扰,严重影响收费CCTV系统图像质量. 展开更多
关键词 高速公路 收费CCTV系统 图像干扰 处理方法 闭路电视监控 随机干扰 单频干扰 电源干扰 脉冲干扰 同步失真 接地干扰 统一接地 单点接地 视频隔离器
下载PDF
一种下行波束赋形与功率控制联合优化的新算法 被引量:1
5
作者 唐旭辉 刘婧歆 蒋泽 《重庆邮电学院学报(自然科学版)》 2003年第1期67-71,共5页
在无线蜂窝系统中 ,当采用下行波束赋形技术时 ,所有用户所接收到的信号必须满足给定的信噪干扰比。由于信噪干扰比的大小与天线的辐射方向图有关 ,故平常所用的技术 (如空间相关矩阵特征值分解技术 )都必须再加以额外的功率控制。提出... 在无线蜂窝系统中 ,当采用下行波束赋形技术时 ,所有用户所接收到的信号必须满足给定的信噪干扰比。由于信噪干扰比的大小与天线的辐射方向图有关 ,故平常所用的技术 (如空间相关矩阵特征值分解技术 )都必须再加以额外的功率控制。提出了一种新的下行波束赋形与功率控制的联合优化算法 ,这种算法不但能够调整权系数以使所有用户具有相同的信噪干扰比 。 展开更多
关键词 下行波束赋形 智能天线 功率控制 信噪干扰比 无线蜂窝系统 联合优化算法
下载PDF
两步单通道语音分离算法
6
作者 温国伟 苍岩 《黑龙江大学工程学报》 2022年第3期79-84,共6页
针对单通道语音分离算法未充分利用语音的相位信息,导致分离的性能不佳,提出了两步单通道语音分离算法。利用特征提取网络作为编码器,波形重构网络作为解码器进行预训练;加入分离模块,利用该模块对提取的声学特征进行操作,估计独立语音... 针对单通道语音分离算法未充分利用语音的相位信息,导致分离的性能不佳,提出了两步单通道语音分离算法。利用特征提取网络作为编码器,波形重构网络作为解码器进行预训练;加入分离模块,利用该模块对提取的声学特征进行操作,估计独立语音信号的掩模。此外,基于TIMIT语音数据集进行仿真实验,与排列不变训练(Permutation invariant training,PIT)算法及其改进的算法进行对比。实验结果表明,提出的方法在信噪失真比(Signal to noise distortion ratio,SDR),信噪伪影比(Signal to noise artifact ratio,SAR),信噪干扰比(Signal to noise interference ratio,SIR)的结果更高,分离性能更优。 展开更多
关键词 单通道 语音分离 特征提取 深度学习 卷积神经网络 失真比 伪影比 信噪干扰比
下载PDF
基于BP神经网络的光伏发电设备故障检测方法研究 被引量:10
7
作者 王宁 王恩路 +2 位作者 韩则胤 韩国强 苏宝定 《自动化仪表》 CAS 2023年第3期88-90,97,共4页
针对光伏发电设备工作过程中存在的故障检测低下问题,设计了集采样、稳压、采样保持和故障采集于一体的集成电路,并提出了故障检测方法。通过分布式测控网络,使系统能够实时、准确地获得光伏发电设备的运行状态。故障检测装置自带计算... 针对光伏发电设备工作过程中存在的故障检测低下问题,设计了集采样、稳压、采样保持和故障采集于一体的集成电路,并提出了故障检测方法。通过分布式测控网络,使系统能够实时、准确地获得光伏发电设备的运行状态。故障检测装置自带计算处理模块智能对比检测数据,为实现故障检测算法提供数据支撑。为了更好地识别光伏发电设备的故障,提出了基于反向传播(BP)神经网络引入可信度检测度量参数的故障监测算法。该算法不仅能够消除误差,并且有很强的抗干扰性。试验结果证明,在不同的干扰信噪比下,检测故障的时间仅在5 ms左右,能够自主地对光伏发电设备运行过程中产生的故障进行识别,极大地提高了光伏发电设备故障检测的工作效率。 展开更多
关键词 光伏发电设备 故障检测 采样电路 反向传播神经网络 归一化 控制芯片 干扰
下载PDF
Generalized Physical Layer Channel Model for RelayBased Super Dense Networks 被引量:1
8
作者 ZHANG Lingwen LIU Chang +1 位作者 ZHANG Jiayi WU Faen 《China Communications》 SCIE CSCD 2015年第8期123-131,共9页
The κ-μ fading model is an advanced channel model in super dense wireless networks.In this paper,we evaluate the performance of the system over κ-μ fading channel in super dense relay networks with consideration o... The κ-μ fading model is an advanced channel model in super dense wireless networks.In this paper,we evaluate the performance of the system over κ-μ fading channel in super dense relay networks with consideration of multiple independent but not necessarily identically distributed(i.n.i.d.) cochannel interference(CCI) under interferencelimited environment.More specifically,we derive a useful and accurate cumulative distribution function(CDF) expression of the end-to-end signal-to-interference plus noise(SINR) ratio.Moreover,we derive novel analytical expressions of the outage probability(OP),average bit error probability(ABEP) and average capacity for binary modulation types and arbitrary positive values of κ-and μ of such system.Furthermore,we propose asymptotic analysis for both the OP and ABEP to give physical insights.A simplified analytical form for the ABEP at high-SNR regimes is provided as well.Finally,the accuracy of the derived expressions is well validated by Monte Carlo simulations. 展开更多
关键词 super dense generalized fadingmodel RELAY co-channel interference DECODE-AND-FORWARD outage probability average biterror probability average capacity.
下载PDF
Robust Digital Non-Linear Self-Interference Cancellation in Full Duplex Radios with Maximum Correntropy Criterion 被引量:3
9
作者 Zhirong Luan Hua Qu +1 位作者 Jihong Zhao Badong Chen 《China Communications》 SCIE CSCD 2016年第9期53-59,共7页
Full duplex radio increases the frequency efficiency but its performance is limited by the self-interference (SI). We first analyze the multiple noises in the full duplex radio system and model such noises as an α ... Full duplex radio increases the frequency efficiency but its performance is limited by the self-interference (SI). We first analyze the multiple noises in the full duplex radio system and model such noises as an α - stable distribution. Then we formulate a novel non-Gaussian SI problem. Under the maximum correntropy criterion (MCC), a robust digital non-linear self-interference cancellation algorithm is proposed for the SI channel estimation. A gradient descent based algorithm is derived to search the optimal solution. Simulation results show that the proposed algorithm can achieve a smaller estimation error and a higher pseudo signal to interference plus noise ratio (PSINR) than the well-known least mean square (LMS) algorithm and least square (LS) algorithm. 展开更多
关键词 full duplex radio robust estimation digital non-linear self-interference can- cellation a-stable noise correntropy
下载PDF
Performance Analysis of Full-Duplex Based Two-Way Relaying 被引量:2
10
作者 Xiaohui Sun Dandan Zhang Xiaoming Dai 《China Communications》 SCIE CSCD 2016年第11期35-48,共14页
Cooperative communication is regarded as a promising technique for improving the reliability of wireless communication links and enhancing the radio coverage simultaneously. Unlike the conventional half-duplex(HD) mod... Cooperative communication is regarded as a promising technique for improving the reliability of wireless communication links and enhancing the radio coverage simultaneously. Unlike the conventional half-duplex(HD) mode relaying techniques,the full-duplex based two-way relaying(FD-TWR) enables data exchanges between two nodes to be completed within a single time-slot,thus resulting in a significant improvement in the spectrum efficiency. In this paper,the channel model of the FD-TWR is first given out,followed by deriving the critical performance metrics,including the received signal-to-interference-plus-noise ratio(SINR),the upper bound of the ergodic capacity and the closedform solution of the proposed FD-TWR under amplify-and-forward(AF) mode. Furthermore,taking the limit of sum-transmit-power into account,we formulate the objective function of the optimal power allocation of FD-TWR as an extreme-value problem by deriving the optimal transmit power for both the source nodes and the relay node. As long as the self-interference(SI) signal in the FD-TWR nodes can be sufficiently suppressed,the proposed scheme is shown to outperform the conventional HD mode in terms of both the ergodic capacity and the outage probability. In addition,regardless of the practical SI power,the proposedFD-TWR is always capable of achieving its best performance with an aid of the proposed optimal power allocation scheme. 展开更多
关键词 full-duplex two-way relaying optimal power allocation ergodic capacity outage probability
下载PDF
Coverage Probability Analysis for Full-Duplex Relay Aided Device-to-Device Communications Networks 被引量:2
11
作者 Bin Zhong Jiajia Zhang +1 位作者 Qian Zeng Xiaoming Dai 《China Communications》 SCIE CSCD 2016年第11期60-67,共8页
The coverage probability of both the cellular users and the Device-to-Device(D2D) users are analyzed. We assume that the cellular users are able to communication with the Base Station(BS) either by relying on the assi... The coverage probability of both the cellular users and the Device-to-Device(D2D) users are analyzed. We assume that the cellular users are able to communication with the Base Station(BS) either by relying on the assistance of Full-Duplex(FD) mode relays or via direct user-to-BS links with high-enough Signal-to-Interference-plus-Noise-Ratio(SINR). Note that the FD-mode devices are capable of simultaneously operating in two modes,i.e. the D2D mode and the cooperative relay mode,with the sum power consumption at these devices kept constant. The closedform expressions for coverage probability of both tier users are derived. After that,numerical analyses are provided,showing that the coverage probability of the both the cellular and the D2D users can be substantially influenced by a variety of parameters,including the power allocation factor of the relays,the density of users,and the self-interference imposed on the FD mode relays,etc. Furthermore,in the D2D enabled networks,it is shown that the FD relay aided transmission is beneficial to enhancing the coverage probability of the cellular users if the target SINR is lower than 5 d B. 展开更多
关键词 cooperative communication coverage probability Full-duplex device-to-device
下载PDF
Capacity Research in Cluster-Based Underwater Wireless Sensor Networks Based on Stochastic Geometry 被引量:2
12
作者 Xia Li Dongxue Zhao 《China Communications》 SCIE CSCD 2017年第6期80-87,共8页
Underwater wireless sensor networks(UWSNs) have attracted wide attention in recent years.The capacity research on it is still in the initial stage,lacking adequate performance evaluation for network construction.This ... Underwater wireless sensor networks(UWSNs) have attracted wide attention in recent years.The capacity research on it is still in the initial stage,lacking adequate performance evaluation for network construction.This paper will focus on this subject by theoretical analysis and simulation,aiming to provide some insights for the actual UWSNs construction.According to the structure features of cluster-based UWSNs and the propagation characteristics of underwater acoustic signal,with the combination of signal to interference plus noise ratio,we define some capacity performance metrics,such as outage probability and transmission capacity.Based on the theory of stochastic geometry,a network capacity analytical model used in the cluster-based UWSNs is presented.The simulation results verify the validity of the theoretical analysis,and the cause of error between theoretical and simulation results has also been clearly explained. 展开更多
关键词 underwater wireless sensor networks cluster-based transmission capacity stochastic geometry
下载PDF
On Multi-Frequency Channel Interference Alignment of 3 Channels and 4 Users 被引量:1
13
作者 DU Guanglong ZOU Weixia ZHOU Zheng 《China Communications》 SCIE CSCD 2016年第1期22-32,共11页
This paper explores the multi-frequency independent channel interference alignment(MFC-IA) system of 3 channels and4 users,and single data stream transmit,i.e.(3×3,1)~4 system.We derive the analytic solution for(... This paper explores the multi-frequency independent channel interference alignment(MFC-IA) system of 3 channels and4 users,and single data stream transmit,i.e.(3×3,1)~4 system.We derive the analytic solution for(3×3,1)~4 MFC-IA system.Based on the analytic solution,an optimization problem is proposed aim at the optimal IA solution.Then based on such a math model,we propose a simulated annealing(SA) algorithm to search optimal IA solution.The simulation results show that the simulated annealing IA algorithm has a better sum rate performance than iterative maximize signal to interference plus noise ratio(Max-SINR) algorithm.This result can be extended to single data stream multi-antenna IA system with 3 antennas and4 users. 展开更多
关键词 communication and information system interference alignment multi-frequency channel analytic solution simulated annealing
下载PDF
Probability density analysis of SINR in massive MIMO systems with matched filter beamformer
14
作者 束锋 Gu Chen +2 位作者 Wang Jin Qian Zhenyu Lu Jinhui 《High Technology Letters》 EI CAS 2015年第3期289-293,共5页
This paper derives an approximate formula for probability density function(PDF) of received signal-to-interference-and-noise ratio(SINR) at user terminal when matched filter(MF) is adopted at a base station(BS).This d... This paper derives an approximate formula for probability density function(PDF) of received signal-to-interference-and-noise ratio(SINR) at user terminal when matched filter(MF) is adopted at a base station(BS).This distribution of SINR can be used to make an analysis of average sum-rate,outage probability,and symbol error rate of massive MIMO downlink with MF at BS.From simulation,it is found that the derived approximate analytical expression for PDF of SINR is consistent with the simulated exact PDF from the definition of SINR in medium-scale and large-scale MIMO systems. 展开更多
关键词 massive MIMO matched filter (MF) signal-to-interference-and-noise ratio SINR) probability density function (PDF)
下载PDF
COEXISTENCE OF PRIMARY USERS AND SECONDARY USERS UNDER INTERFERENCE TEMPERATURE AND SINR LIMIT
15
作者 Wu Yingxiao Yang Zhen 《Journal of Electronics(China)》 2009年第3期303-311,共9页
Spectrum sharing offers the opportunity for promising efficiency gains, and it will be a valuable tool in the era of future radios.To address this issue, we develop a multi-user cognitive radio sharing network based o... Spectrum sharing offers the opportunity for promising efficiency gains, and it will be a valuable tool in the era of future radios.To address this issue, we develop a multi-user cognitive radio sharing network based on opportunistic spectrum access and propose a new spectrum sharing strategy.The objective of our interest is to obtain the number of secondary users who can coexist peacefully with primary users to improve the utility of licensed spectrum, at the same time maximize the total goodput under the interference temperature and SINR constraints.Through analysis and simulation, the new strategy of spectrum sharing does improve the goodput performance as well as guarantee the Quality of Service(QoS) of primary and secondary users. 展开更多
关键词 Spectrum sharing COEXISTENCE Interference temperature limit SINR limit Opportunistic spectrum access
下载PDF
Neighbour Peer Selection Scheme Based on Effective Capacity for Mobile Peer-to-Peer Streaming
16
作者 夏海轮 王宁 曾志民 《China Communications》 SCIE CSCD 2013年第5期89-98,共10页
For Peer-to-Peer (P2P) streaming services in mobile networks, the selection of appropriate neighbour peers from candidate peers with demanding data is an important approach to improve Quality-of-Service (QoS). This pa... For Peer-to-Peer (P2P) streaming services in mobile networks, the selection of appropriate neighbour peers from candidate peers with demanding data is an important approach to improve Quality-of-Service (QoS). This paper proposes a novel Effective Capacity Peer Selection (ECPS) scheme based on effective capacity. In the ECPS scheme, the neighbour peer selection problem was modeled using the Multiple Attribute Decision Making (MADM) theory, which considered multiple factors of candidate peers, including Signal to Interference and Noise Ratio (SINR), residency time, power level, security, moving speed, and effective capacity. This model could increase the suitability of ECPS for wireless mobile environments. Then, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was used to solve the MADM problem and identify the preferred neighbour peers. Simulation results show that the ECPS scheme can improve the network throughput, reduce packet delay by about 82%, and almost double the packet delivery ratio of the mobile P2P streaming service. 展开更多
关键词 P2P mobile P2P streaming peer selection effective capacity MADM QoS
下载PDF
Security-Oriented Transmission Based on Cooperative Relays in Cognitive Radio
17
作者 王莉 马鑫 +2 位作者 马跃 滕颖蕾 张勇 《China Communications》 SCIE CSCD 2013年第8期27-35,共9页
In this paper,we propose a securityoriented transmission scheme with the help of multiple relays in Cognitive Radio(CR).To maximise the Secrecy Capacity(SC)of the source-destination link in CR,both beamforming and coo... In this paper,we propose a securityoriented transmission scheme with the help of multiple relays in Cognitive Radio(CR).To maximise the Secrecy Capacity(SC)of the source-destination link in CR,both beamforming and cooperative jamming technologies are used to improve the performance of the Secondary User(SU)and protect the Primary User(PU).The effectiveness of the proposed scheme is demonstrated using extensive simulation.Both theoretical analyses and simulation results reveal that the proposed scheme contributes to the secure transmission of the SU with acceptable attenuation of the Signal-to-Noise Ratio(SNR)at the PU receiver,and the upper bound of the SC at the SU receiver is able to exploit the power allocation strategy. 展开更多
关键词 CR SC power allocation acceptable SNR attenuation level
下载PDF
Duplexer Design for Full-Duplex Based Wireless Communications
18
作者 Hui Zhuang Jintao Li +1 位作者 Weibiao Geng Xiaoming Dai 《China Communications》 SCIE CSCD 2016年第11期1-13,共13页
The full-duplex(FD) based wireless communication devices,which are capable of concurrently transmitting and receiving signals with a single frequency band,suffer from a severe self-interference(SI) due to the large po... The full-duplex(FD) based wireless communication devices,which are capable of concurrently transmitting and receiving signals with a single frequency band,suffer from a severe self-interference(SI) due to the large power difference between the devices' own transmission and the useful signal comes from the remote transmitters. To enable the practical FD devices to be implementable,the SI power must be sufficiently suppressed to the level of background noise power,making the received signal-to-interference-plus-noise ratio(SINR) satisfy the decoding requirement. In this paper,the design and implementation of the duplexer for facilitating SI cancellation in FD based wireless communications are investigated,with a new type of duplexer(i.e. an improved directional coupler) designed for improving the spatial suppression of the SI power. Furthermore,the practical circuit boards are designed and verified for the proposed prototype,showing that the spatial suppression capability may be up to 36 d B(i.e. much higher than that attainable in the commonly designed ferrite circulator) by using the proposed design. 展开更多
关键词 full-duplex wireless communications Self-interference cancellation DUPLEXER Directional coupler
全文增补中
Hybrid coordinated strategy of downlink coordinated multi-point transmission 被引量:2
19
作者 Zhuoming Li Yuqi Liu +3 位作者 Yu Zhang Peng Wang Chunyang Tian Xuejun Sha 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第5期916-923,共8页
Coordinated multi-point (CoMP) transmission is put forward in the long term evolution-advanced (LTE-A) system to improve both average and cell-edge throughput. CoMP-joint pro- cessing (JP) scheme can get a large... Coordinated multi-point (CoMP) transmission is put forward in the long term evolution-advanced (LTE-A) system to improve both average and cell-edge throughput. CoMP-joint pro- cessing (JP) scheme can get a larger cell-edge throughput and a lower bit error rate (BER) than the CoMP-coordinated beamform- ing (CB) scheme, but it also has higher complexity due to data sharing. A hybrid coordinated strategy with parameter c~, which indicates the proportion of users employing the CoMP-JP scheme, is proposed to apply the CoMP-JP scheme to improve the poorer communication quality of cell edge and employ the CoMP-CB scheme for other users to enhance average throughput and spec- tral efficiency. This paradigm selects users defined by the certain threshold of signal to interference plus noise power ratio (SINR) corresponding to the parameter a to the CoMP-JP scheme. This paper compares the BER performance between the block diag- onalization (BD) based precoding and the linear precoders by maximizing signal to leakage and noise ratio (SLNR), and also in- dicates that the SLNR based precoding algorithm gets lower BER than the BD based precoding algorithm with certain signal-to-noise ratios (SNRs). Finally, this paper discusses that the system perfor- mance is partially affected by the percentage of CoMP-JP users and concludes that 50% of users sorted to communicate under the CoMP-JP scheme will reach the best system performance. 展开更多
关键词 coordinated multi-point (CoMP) block diagonalization(BD) signal to leakage and noise ratio (SLNR) hybrid coordinatedstrategy
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部