This paper proposes the design and development of a novel, portable and low-cost intelligent electronic device (IED) for real-time monitoring of high frequency phenomena in CENELEC PLC band. A high speed floating-poin...This paper proposes the design and development of a novel, portable and low-cost intelligent electronic device (IED) for real-time monitoring of high frequency phenomena in CENELEC PLC band. A high speed floating-point digital signal processor (DSP) along with 4 MSPS analog-to-digital converter (ADC) is used to develop the intelligent electronic device. An optimized algorithm to process the analog signal in real-time and to extract the meaningful result using signal processing techniques has been implemented on the device. A laboratory environment has setup with all the necessary equipment including the development of the load model to evaluate the performance of the IED. Smart meter and concentrator is also connected to the low voltage (LV) network to monitor the PLC communication using the IED. The device has been tested in the laboratory and it has produced very promising results for time domain as well as frequency domain analysis. Those results imply that the IED is fully capable of monitoring high frequency disturbances in CENELEC PLC band.展开更多
针对正交频分复用(OFDM)系统中由频率偏移引起的子载波间干扰(ICI)的问题,提出了一种基于对称子载波的ICI自消除算法。该算法将互为相反数的发送符号映射到对称的子载波上,并在接收端将解调信号进行线性组合。为了进一步降低ICI,将基于...针对正交频分复用(OFDM)系统中由频率偏移引起的子载波间干扰(ICI)的问题,提出了一种基于对称子载波的ICI自消除算法。该算法将互为相反数的发送符号映射到对称的子载波上,并在接收端将解调信号进行线性组合。为了进一步降低ICI,将基于对称子载波的ICI自消除算法与时域加窗相结合,即在发送数据符号之前,与升余弦函数相乘。对算法进行仿真实验,相对于相邻符号自消除算法,该算法减小了子载波间的干扰系数;加窗后OFDM符号频谱的边瓣衰减速度快,最大可衰减至-40 d B;对于系统的信号干扰比性能(SIR),加窗后的算法同相邻符号自消除算法相比可提高8 d B左右;在信噪比较大的情况下,改善了系统的误码率。仿真结果表明,所提算法能够抑制ICI,提高系统抗干扰性能。展开更多
A distributed power allocation scheme was presented to maximize the system capacity in dense small cell networks. A new signaling called inter-cell-signal to interference plus noise ratio （ISINR） as well as its modi...A distributed power allocation scheme was presented to maximize the system capacity in dense small cell networks. A new signaling called inter-cell-signal to interference plus noise ratio （ISINR） as well as its modification was defined to show the algebraic properties of the system capacity. With the help of ISINR, we have an easy way to identify the local monotonicity of the system capacity. Then on each subchannel in iteration, we divide the small cell evolved node B＇s （SeNBs） into different subsets. For the first subset, the sum rate is convex with respect to the power domain and the power optimally was allocated. On the other hand, for the second subset, the sum rate is monotone decreasing and the SeNBs would abandon the subchannel in this iteration. The two strategies are applied iteratively to improve the system capacity. Simulations show that the proposed scheme can achieve much larger system capacity than the conventional ones. The scheme can achieve a promising tradeoffbetween performance and signaling overhead.展开更多
将基于信号功率排序的QR分解算法与最后检测层分集增益最大算法相结合,提出一种改进的SQRD(Sorted QR Decomposition)算法。该改进算法在串行干扰消除SQRD算法的基础上最大化了分集增益。这样既能保证每次检测时的最先检测层信号功率最...将基于信号功率排序的QR分解算法与最后检测层分集增益最大算法相结合,提出一种改进的SQRD(Sorted QR Decomposition)算法。该改进算法在串行干扰消除SQRD算法的基础上最大化了分集增益。这样既能保证每次检测时的最先检测层信号功率最大,又能得到最后检测层的最大分集增益。同时采用了串行干扰消除,使后面的信道矩阵维数不断减少,降低了检测复杂度。仿真结果表明,改进的SQRD算法在误码性能上取得了较好的表现,尤其在接收天线数较大时误码性能得到明显改善。改进的算法在复杂度和性能上得到较好的平衡,很适合VBLAST系统的信号检测。展开更多
文摘This paper proposes the design and development of a novel, portable and low-cost intelligent electronic device (IED) for real-time monitoring of high frequency phenomena in CENELEC PLC band. A high speed floating-point digital signal processor (DSP) along with 4 MSPS analog-to-digital converter (ADC) is used to develop the intelligent electronic device. An optimized algorithm to process the analog signal in real-time and to extract the meaningful result using signal processing techniques has been implemented on the device. A laboratory environment has setup with all the necessary equipment including the development of the load model to evaluate the performance of the IED. Smart meter and concentrator is also connected to the low voltage (LV) network to monitor the PLC communication using the IED. The device has been tested in the laboratory and it has produced very promising results for time domain as well as frequency domain analysis. Those results imply that the IED is fully capable of monitoring high frequency disturbances in CENELEC PLC band.
文摘针对正交频分复用(OFDM)系统中由频率偏移引起的子载波间干扰(ICI)的问题,提出了一种基于对称子载波的ICI自消除算法。该算法将互为相反数的发送符号映射到对称的子载波上,并在接收端将解调信号进行线性组合。为了进一步降低ICI,将基于对称子载波的ICI自消除算法与时域加窗相结合,即在发送数据符号之前,与升余弦函数相乘。对算法进行仿真实验,相对于相邻符号自消除算法,该算法减小了子载波间的干扰系数;加窗后OFDM符号频谱的边瓣衰减速度快,最大可衰减至-40 d B;对于系统的信号干扰比性能(SIR),加窗后的算法同相邻符号自消除算法相比可提高8 d B左右;在信噪比较大的情况下,改善了系统的误码率。仿真结果表明,所提算法能够抑制ICI,提高系统抗干扰性能。
基金supported by the Hi-Tech Research and Development Program of China (2014AA01A701)the Funds for Creative Research Groups of China (61121001)
文摘A distributed power allocation scheme was presented to maximize the system capacity in dense small cell networks. A new signaling called inter-cell-signal to interference plus noise ratio （ISINR） as well as its modification was defined to show the algebraic properties of the system capacity. With the help of ISINR, we have an easy way to identify the local monotonicity of the system capacity. Then on each subchannel in iteration, we divide the small cell evolved node B＇s （SeNBs） into different subsets. For the first subset, the sum rate is convex with respect to the power domain and the power optimally was allocated. On the other hand, for the second subset, the sum rate is monotone decreasing and the SeNBs would abandon the subchannel in this iteration. The two strategies are applied iteratively to improve the system capacity. Simulations show that the proposed scheme can achieve much larger system capacity than the conventional ones. The scheme can achieve a promising tradeoffbetween performance and signaling overhead.
文摘将基于信号功率排序的QR分解算法与最后检测层分集增益最大算法相结合,提出一种改进的SQRD(Sorted QR Decomposition)算法。该改进算法在串行干扰消除SQRD算法的基础上最大化了分集增益。这样既能保证每次检测时的最先检测层信号功率最大,又能得到最后检测层的最大分集增益。同时采用了串行干扰消除,使后面的信道矩阵维数不断减少,降低了检测复杂度。仿真结果表明,改进的SQRD算法在误码性能上取得了较好的表现,尤其在接收天线数较大时误码性能得到明显改善。改进的算法在复杂度和性能上得到较好的平衡,很适合VBLAST系统的信号检测。
