In orthogonal frequency-division multiplexing （OFDM） systems, the carrier frequency offset （CFO） destroys the orthogonality among subcarriers which degrades system performance. Various CFO estimation methods have ...In orthogonal frequency-division multiplexing （OFDM） systems, the carrier frequency offset （CFO） destroys the orthogonality among subcarriers which degrades system performance. Various CFO estimation methods have been developed to compensate for the CFO at the receiver. This paper describes a novel minimum output variance method for OFDM systems with CFO in additive white Gaussian noise channels. This method utilizes the phase and the amplitude of the received signal and reduces the mean square error of the CFO by about 3 dB compared with the original minimum output variance method.展开更多
提出了 STBC MIMOCDMA 系统中一种新的基于多用户 ML 估计的带制约的最小方差无失真响应(CMVDR)接收机,能有效抑制多址干扰(MAI)和符号间干扰(ISI)。给出了多用户、多径的 STBC MIMO CDMA 系统信道模型及 ML 参数估计,并给出了分部加权...提出了 STBC MIMOCDMA 系统中一种新的基于多用户 ML 估计的带制约的最小方差无失真响应(CMVDR)接收机,能有效抑制多址干扰(MAI)和符号间干扰(ISI)。给出了多用户、多径的 STBC MIMO CDMA 系统信道模型及 ML 参数估计,并给出了分部加权和整体加权两种 CMVDR 接收机,本接收机也适用于 SIMO CDMA系统。进行了系统模拟,并对分部加权和整体加权两种 CMVDR 接收机的性能以及自适应 CMMSE 接收机的性能进行了比较分析。展开更多
This paper proposes the modeling and simulation technique to analyze and design a Boost converter using generalized minimum variance method with discrete-time quasi-sliding mode to adjust the converter switch through ...This paper proposes the modeling and simulation technique to analyze and design a Boost converter using generalized minimum variance method with discrete-time quasi-sliding mode to adjust the converter switch through a pulse width modulation (PWM), so as to enhance a stable output voltage. The control objective is to maintain the sensed output voltage stable, constant and equal to some constant reference voltage (8 volt) in the load resistance variation (24, 48, 240) Ω and input voltage variation (20, 24, 28) volt circumstances. This control strategy is very appropriate for the digitally controlled power converter and for the system requirement accomplishment, resulting high output voltage accuracy. The performance degradation in practical implementation can be expected due to noise, PWM nonlinearities, and components imperfection. The digital simulation using MATHLAB/Simulink is performed to validate the functionality of the system.展开更多
基金Supported by the Major Program of the National Natural Science Foundation of China (No. 60496311) Basic Research Foundation of Tsinghua National Laboratory for Information Sci-ence and Technology (TNList)
文摘In orthogonal frequency-division multiplexing （OFDM） systems, the carrier frequency offset （CFO） destroys the orthogonality among subcarriers which degrades system performance. Various CFO estimation methods have been developed to compensate for the CFO at the receiver. This paper describes a novel minimum output variance method for OFDM systems with CFO in additive white Gaussian noise channels. This method utilizes the phase and the amplitude of the received signal and reduces the mean square error of the CFO by about 3 dB compared with the original minimum output variance method.
文摘提出了 STBC MIMOCDMA 系统中一种新的基于多用户 ML 估计的带制约的最小方差无失真响应(CMVDR)接收机,能有效抑制多址干扰(MAI)和符号间干扰(ISI)。给出了多用户、多径的 STBC MIMO CDMA 系统信道模型及 ML 参数估计,并给出了分部加权和整体加权两种 CMVDR 接收机,本接收机也适用于 SIMO CDMA系统。进行了系统模拟,并对分部加权和整体加权两种 CMVDR 接收机的性能以及自适应 CMMSE 接收机的性能进行了比较分析。
文摘This paper proposes the modeling and simulation technique to analyze and design a Boost converter using generalized minimum variance method with discrete-time quasi-sliding mode to adjust the converter switch through a pulse width modulation (PWM), so as to enhance a stable output voltage. The control objective is to maintain the sensed output voltage stable, constant and equal to some constant reference voltage (8 volt) in the load resistance variation (24, 48, 240) Ω and input voltage variation (20, 24, 28) volt circumstances. This control strategy is very appropriate for the digitally controlled power converter and for the system requirement accomplishment, resulting high output voltage accuracy. The performance degradation in practical implementation can be expected due to noise, PWM nonlinearities, and components imperfection. The digital simulation using MATHLAB/Simulink is performed to validate the functionality of the system.
