A decoding method complemented by Maximum Likelihood (ML) detection for V-BLAST (Verti- cal Bell Labs Layered Space-Time) system is presented. The ranked layers are divided into several groups. ML decoding is performe...A decoding method complemented by Maximum Likelihood (ML) detection for V-BLAST (Verti- cal Bell Labs Layered Space-Time) system is presented. The ranked layers are divided into several groups. ML decoding is performed jointly for the layers within the same group while the Decision Feedback Equalization (DFE) is performed for groups. Based on the assumption of QPSK modulation and the quasi-static flat fading channel, simulations are made to testify the performance of the proposed algorithm. The results show that the algorithm outperforms the original V-BLAST detection dramatically in Symbol Error Probability (SEP) per- formance. Specifically, Signal-to-Noise Ratio (SNR) improvement of 3.4dB is obtained for SEP of 10?2 (4×4 case), with a reasonable complexity maintained.展开更多
An asynchronous transmission scenario for non-orthogonal multiple access(NOMA)user signals with arbitrary phase offset is investigated in this paper.To improve the system performance in the user power-balanced conditi...An asynchronous transmission scenario for non-orthogonal multiple access(NOMA)user signals with arbitrary phase offset is investigated in this paper.To improve the system performance in the user power-balanced conditions,we adopt a synthetic detection method at the receiver,i.e.,the jointly optimal maximal likelihood detection aided triangular successive interference cancellation(JO ML-TSIC)method.Analytical bit error rate(BER)solutions are obtained for a two-user case with the optimal,intentional onehalf symbol period time delay implemented between the user signals.Furthermore,closed-form BER solutions for the case using the triangular successive interference cancellation(TSIC)detection method are also derived for comparisons.Numerical results show that the JO ML-TSIC receiver for the asynchronous system outperforms the TSIC receiver as well as the synchronous successive interference cancellation(SIC)receiver in all the conditions concerned.The results also show that the superiority of the JO ML-TSIC receiver is strengthened when the signals experience flat Rayleigh fading channels compared to the TSIC and the synchronous SIC receivers.展开更多
Accurate topology estimation is crucial for effectively operating modern distribution networks.Line outages in a distribution network change the network topology by disconnecting some parts of the network from the mai...Accurate topology estimation is crucial for effectively operating modern distribution networks.Line outages in a distribution network change the network topology by disconnecting some parts of the network from the main grid.In this paper,an outage detection(or topology estimation)algorithm for radial distribution networks is presented.The algorithm utilizes noisy power flow measurements collected from a subset of lines in the network,and statistical information characterizing errors in forecasting load demands.Additionally,a sensor placement scheme is presented.The sensor placement provides critical sensing for the outage detection algorithm so that any number of possible outages in the network can be detected.The performance of the proposed outage detection algorithm using the proposed sensor placement is demonstrated through several numerical results on the IEEE 123-node test feeder.展开更多
SM (spatial multiplexing) can effectively increase the information rate in multiple input multiple output system. BLAST is the typical representation of SM, especially VBLAST, which has some simple de- tection algorit...SM (spatial multiplexing) can effectively increase the information rate in multiple input multiple output system. BLAST is the typical representation of SM, especially VBLAST, which has some simple de- tection algorithms such as ML, ZF-DFE and ML-DFE, etc. However, the existing algorithms cannot approach ML performance. This paper discusses the effect for detection performance by the correlation of channel ma- trix, proposes a new algorithm—HPML detection algorithm, which can approach ML performance with low complexity. In the new algorithm, we travel the first d layers, and use the DFE procedure for the remaining layers, then perform ML detection for all obtained signals. Simulation results show that HPML can approach ML performance when the traveling numbers are not less than half of the number of transmitting antennas, and the algorithm complexity is smaller than ML.展开更多
This paper presents a novel incremental relaying protocol based on spatial modulation for cooperative transmission over quasi-static rayleigh fading channel, namely spatial modulation incremental relaying （SMIR）, wh...This paper presents a novel incremental relaying protocol based on spatial modulation for cooperative transmission over quasi-static rayleigh fading channel, namely spatial modulation incremental relaying （SMIR）, which applies the concept of spatial modulation into incremental relaying. In the proposed protocol, information bits are mapped into two information carrying units： 1） a constellation point in the constellation diagram and 2） the spatial domain, i.e. into the location of a particular cooperative user number. The analytical expression of the frame error rate （FER） for SMIR protocol is derived. Simulation results confirm the presented mathematical analysis and show that SMIR protocol gains 2 and 3 dB in signal to noise ratio （SNR） over the conventional protocol for 3-and 5-bit/symbol transmissions respectively. Moreover, under this protocol the system can achieve a much higher throughput, which means that our proposed protocol brings significant gain in performance.展开更多
基金Supported by the National Natural Science Foundation of China (No.60172029).
文摘A decoding method complemented by Maximum Likelihood (ML) detection for V-BLAST (Verti- cal Bell Labs Layered Space-Time) system is presented. The ranked layers are divided into several groups. ML decoding is performed jointly for the layers within the same group while the Decision Feedback Equalization (DFE) is performed for groups. Based on the assumption of QPSK modulation and the quasi-static flat fading channel, simulations are made to testify the performance of the proposed algorithm. The results show that the algorithm outperforms the original V-BLAST detection dramatically in Symbol Error Probability (SEP) per- formance. Specifically, Signal-to-Noise Ratio (SNR) improvement of 3.4dB is obtained for SEP of 10?2 (4×4 case), with a reasonable complexity maintained.
基金supported by the National Natural Science Foundation of China (Grant No. 62022019)
文摘An asynchronous transmission scenario for non-orthogonal multiple access(NOMA)user signals with arbitrary phase offset is investigated in this paper.To improve the system performance in the user power-balanced conditions,we adopt a synthetic detection method at the receiver,i.e.,the jointly optimal maximal likelihood detection aided triangular successive interference cancellation(JO ML-TSIC)method.Analytical bit error rate(BER)solutions are obtained for a two-user case with the optimal,intentional onehalf symbol period time delay implemented between the user signals.Furthermore,closed-form BER solutions for the case using the triangular successive interference cancellation(TSIC)detection method are also derived for comparisons.Numerical results show that the JO ML-TSIC receiver for the asynchronous system outperforms the TSIC receiver as well as the synchronous successive interference cancellation(SIC)receiver in all the conditions concerned.The results also show that the superiority of the JO ML-TSIC receiver is strengthened when the signals experience flat Rayleigh fading channels compared to the TSIC and the synchronous SIC receivers.
基金supported by the U.S.Department of Energy(No.DEOE0000779)the U.S.Department of Energy Grid Modernization Laboratory Consortium(GMLC)。
文摘Accurate topology estimation is crucial for effectively operating modern distribution networks.Line outages in a distribution network change the network topology by disconnecting some parts of the network from the main grid.In this paper,an outage detection(or topology estimation)algorithm for radial distribution networks is presented.The algorithm utilizes noisy power flow measurements collected from a subset of lines in the network,and statistical information characterizing errors in forecasting load demands.Additionally,a sensor placement scheme is presented.The sensor placement provides critical sensing for the outage detection algorithm so that any number of possible outages in the network can be detected.The performance of the proposed outage detection algorithm using the proposed sensor placement is demonstrated through several numerical results on the IEEE 123-node test feeder.
文摘SM (spatial multiplexing) can effectively increase the information rate in multiple input multiple output system. BLAST is the typical representation of SM, especially VBLAST, which has some simple de- tection algorithms such as ML, ZF-DFE and ML-DFE, etc. However, the existing algorithms cannot approach ML performance. This paper discusses the effect for detection performance by the correlation of channel ma- trix, proposes a new algorithm—HPML detection algorithm, which can approach ML performance with low complexity. In the new algorithm, we travel the first d layers, and use the DFE procedure for the remaining layers, then perform ML detection for all obtained signals. Simulation results show that HPML can approach ML performance when the traveling numbers are not less than half of the number of transmitting antennas, and the algorithm complexity is smaller than ML.
基金supported by the National Natural Science Foundation of China for Young Scholar (61001115)
文摘This paper presents a novel incremental relaying protocol based on spatial modulation for cooperative transmission over quasi-static rayleigh fading channel, namely spatial modulation incremental relaying （SMIR）, which applies the concept of spatial modulation into incremental relaying. In the proposed protocol, information bits are mapped into two information carrying units： 1） a constellation point in the constellation diagram and 2） the spatial domain, i.e. into the location of a particular cooperative user number. The analytical expression of the frame error rate （FER） for SMIR protocol is derived. Simulation results confirm the presented mathematical analysis and show that SMIR protocol gains 2 and 3 dB in signal to noise ratio （SNR） over the conventional protocol for 3-and 5-bit/symbol transmissions respectively. Moreover, under this protocol the system can achieve a much higher throughput, which means that our proposed protocol brings significant gain in performance.
