Orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) has been proven to be a promising multi-carrier modulation (MCM) technique for the transmission of signals over multipath fading channels. However, OFDM/O...Orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) has been proven to be a promising multi-carrier modulation (MCM) technique for the transmission of signals over multipath fading channels. However, OFDM/OQAM has also the intrinsic disadvantage of high peak-to-average-power ratio (PAPR) that should be alleviated. This paper focuses on the reduction of the clipping noise and out-of band radiation caused by the clipping process. The basic principle is to estimate the clipping noise and then eliminate it from the received signal. Analysis and simulation results show that, with one time iteration, the proposed method can effectively improve the bit error ratio (BER) performance.展开更多
脉冲噪声是制约基于正交频分复用技术(OFDM)的电力线通信系统可靠性提高的最大瓶颈。采用置0(Blanking)/限幅(Clipping)相结合的非线性噪声抑制方法被认为是能够减弱噪声的一种有效途径,这种方法中存在两个阈值——T和T/a。其中T为Blank...脉冲噪声是制约基于正交频分复用技术(OFDM)的电力线通信系统可靠性提高的最大瓶颈。采用置0(Blanking)/限幅(Clipping)相结合的非线性噪声抑制方法被认为是能够减弱噪声的一种有效途径,这种方法中存在两个阈值——T和T/a。其中T为Blanking阈值,T/a为Clipping阈值,a为比例因子。之前的大多数研究主要是通过寻找最优阈值T来提高噪声抑制能力,而忽略了比例因子a的优化。基于此,提出一种估计最优比例因子的方法,从而改善采用置0(Blanking)/限幅(Clipping)相结合的算法的性能,并在G3-PLC协议下分别对电力线通信系统的输出信噪比和误码率进行仿真,仿真结果表明,提出的算法使得系统的误码率降低了0.02 d B,系统的输出信噪比提升0.3 d B。展开更多
为降低正交频分复用(Orthogonal Frequency Division Multip-lexing,OFDM)系统峰均功率比(Peak to Average Power Ratio,PAPR),在最近提出的限幅噪声压缩(Clipping-noise Compression,CNC)方法基础上,提出了一种基于改进的艾里压缩函数...为降低正交频分复用(Orthogonal Frequency Division Multip-lexing,OFDM)系统峰均功率比(Peak to Average Power Ratio,PAPR),在最近提出的限幅噪声压缩(Clipping-noise Compression,CNC)方法基础上,提出了一种基于改进的艾里压缩函数来抑制限幅噪声的方法(CNC-Improved Airy Function,CNC-IAF)。改进的艾里压缩函数形式简单,计算复杂度较小,并且对归一化限幅噪声的取值条件没有CNC方法的严格。仿真结果表明,CNC-IAF方法能够抑制OFDM信号的PAPR同时有效地降低系统误码率,性能比CNC方法均有改善。展开更多
文摘Orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) has been proven to be a promising multi-carrier modulation (MCM) technique for the transmission of signals over multipath fading channels. However, OFDM/OQAM has also the intrinsic disadvantage of high peak-to-average-power ratio (PAPR) that should be alleviated. This paper focuses on the reduction of the clipping noise and out-of band radiation caused by the clipping process. The basic principle is to estimate the clipping noise and then eliminate it from the received signal. Analysis and simulation results show that, with one time iteration, the proposed method can effectively improve the bit error ratio (BER) performance.
文摘脉冲噪声是制约基于正交频分复用技术(OFDM)的电力线通信系统可靠性提高的最大瓶颈。采用置0(Blanking)/限幅(Clipping)相结合的非线性噪声抑制方法被认为是能够减弱噪声的一种有效途径,这种方法中存在两个阈值——T和T/a。其中T为Blanking阈值,T/a为Clipping阈值,a为比例因子。之前的大多数研究主要是通过寻找最优阈值T来提高噪声抑制能力,而忽略了比例因子a的优化。基于此,提出一种估计最优比例因子的方法,从而改善采用置0(Blanking)/限幅(Clipping)相结合的算法的性能,并在G3-PLC协议下分别对电力线通信系统的输出信噪比和误码率进行仿真,仿真结果表明,提出的算法使得系统的误码率降低了0.02 d B,系统的输出信噪比提升0.3 d B。
文摘为降低正交频分复用(Orthogonal Frequency Division Multip-lexing,OFDM)系统峰均功率比(Peak to Average Power Ratio,PAPR),在最近提出的限幅噪声压缩(Clipping-noise Compression,CNC)方法基础上,提出了一种基于改进的艾里压缩函数来抑制限幅噪声的方法(CNC-Improved Airy Function,CNC-IAF)。改进的艾里压缩函数形式简单,计算复杂度较小,并且对归一化限幅噪声的取值条件没有CNC方法的严格。仿真结果表明,CNC-IAF方法能够抑制OFDM信号的PAPR同时有效地降低系统误码率,性能比CNC方法均有改善。
