This paper proposes an efficient approximate Maximum Likelihood (ML) detection method for Multiple-Input Multiple-Output (MIMO) systems,which searches local area instead of exhaustive search and selects valid search p...This paper proposes an efficient approximate Maximum Likelihood (ML) detection method for Multiple-Input Multiple-Output (MIMO) systems,which searches local area instead of exhaustive search and selects valid search points in each transmit antenna signal constellation instead of all hy-perplane. Both of the selection and search complexity can be reduced significantly. The method per-forms the tradeoff between computational complexity and system performance by adjusting the neighborhood size to select the valid search points. Simulation results show that the performance is comparable to that of the ML detection while the complexity is only as the small fraction of ML.展开更多
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 joint...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
Various efficient generalized sphere decoding (GSD) algorithms have been proposed to approach optimal ML performance for underdetermined linear systems, by transforming the original problem into the full-column-rank o...Various efficient generalized sphere decoding (GSD) algorithms have been proposed to approach optimal ML performance for underdetermined linear systems, by transforming the original problem into the full-column-rank one so that standard SD can be fully applied. However, their design parameters are heuristically set based on observation or the possibility of an ill-conditioned transformed matrix can affect their searching efficiency. This paper presents a better transformation to alleviate the ill-conditioned structure and provides a systematic approach to select design parameters for various GSD algorithms in order to high efficiency. Simulation results on the searching performance confirm that the proposed techniques can provide significant improvement.展开更多
In this paper,we propose an efficient fall detection system in enclosed environments based on single Gaussian model using the maximum likelihood method.Online video clips are used to extract the features from two came...In this paper,we propose an efficient fall detection system in enclosed environments based on single Gaussian model using the maximum likelihood method.Online video clips are used to extract the features from two cameras.After the model is constructed,a threshold is set,and the probability for an incoming sample under the single Gaussian model is compared with that threshold to make a decision.Experimental results show that if a proper threshold is set,a good recognition rate for fall activities can be achieved.展开更多
文摘This paper proposes an efficient approximate Maximum Likelihood (ML) detection method for Multiple-Input Multiple-Output (MIMO) systems,which searches local area instead of exhaustive search and selects valid search points in each transmit antenna signal constellation instead of all hy-perplane. Both of the selection and search complexity can be reduced significantly. The method per-forms the tradeoff between computational complexity and system performance by adjusting the neighborhood size to select the valid search points. Simulation results show that the performance is comparable to that of the ML detection while the complexity is only as the small fraction of ML.
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.
文摘Various efficient generalized sphere decoding (GSD) algorithms have been proposed to approach optimal ML performance for underdetermined linear systems, by transforming the original problem into the full-column-rank one so that standard SD can be fully applied. However, their design parameters are heuristically set based on observation or the possibility of an ill-conditioned transformed matrix can affect their searching efficiency. This paper presents a better transformation to alleviate the ill-conditioned structure and provides a systematic approach to select design parameters for various GSD algorithms in order to high efficiency. Simulation results on the searching performance confirm that the proposed techniques can provide significant improvement.
文摘In this paper,we propose an efficient fall detection system in enclosed environments based on single Gaussian model using the maximum likelihood method.Online video clips are used to extract the features from two cameras.After the model is constructed,a threshold is set,and the probability for an incoming sample under the single Gaussian model is compared with that threshold to make a decision.Experimental results show that if a proper threshold is set,a good recognition rate for fall activities can be achieved.
