We are concerned with the issue of detecting changes of clustering structures from multivariate time series. From the viewpoint of the minimum description length (MDL) principle, we introduce an algorithm that tracks changes of clustering structures so that the sum of the code-length for data and that for clustering changes is minimum. Here we employ a Gaussian mixture model (GMM) as representa...

Maximum-Likelihood (ML) detection problem in communication is known to be NP(Non-deterministic Polynomial time)-hard. The computational complexity of solving ML detection is exponential in the size of the problem with exhaustive search that provides optimal solution. Several suboptimum algorithms have been proposed in the literature that provide reliable performance with reduced complexity. But...

A maximum likelihood (ML) technique for detecting compact sources in images of the x-ray sky is examined. Such images, in the relatively low exposure regime accessible to present x-ray observatories, exhibit Poissonian noise at background flux levels. A variety of source detection methods are compared via Monte Carlo, and the ML detection method is shown to compare favourably with the optimized...

We apply joint maximum likelihood (ML) estimation to orthogonal frequency division multiplexing (OFDM) systems and develop a simple receiver structure that gives joint ML estimates of a multipath channel and the transmitted data sequence. Simulation results have confirmed good performance of our algorithm. For a two-path or three-path slow fading channel, our algorithm converges to the case wit...

This paper introduces a simple combining technique for cooperative relay scheme which is based on a Detect-and-Forward (DEF) relay protocol. Cooperative relay schemes have been introduced in earlier works but most of them ignore the quality of the source-relay (S-R) channel in the detection at the destination, although this channel can contribute heavily to the performance of cooperation scheme...

Third-generation mobile radio networks have been under intense research. Code division multiple access (CDMA) has emerged as the mainstream air interface solution for the third-generation networks. As the demand of usable bandwidth is ever increasing, multiuser detection is a necessary means for CDMA systems to reduce effect of multiple access interference and hence increase system capacity. Th...

Upper and lower bounds on the BER performance of the maximum likelihood detection of uncoded transmission in a SC-FDMA setting are derived for a Rayleigh fading channel. Approximated closed-form expressions are derived for the lower bound of the BER performance for high and low SNR regimes. These derivations are validated by simulation.

In this paper, we propose a simplified Maximum Likelihood (ML) detection scheme for Multiple-Input Multiple-Output (MIMO) system that has much less computational complexity than the conventional ML detection scheme. Simulation results verify that the bit error rate (BER) performance of the proposed scheme is close to that of the ML detection scheme with significant complexity reduction. key wor...

In this paper, we propose a novel noncoherent maximum likelihood detection (NMLD) method for differential spatial multiplexing (SM) multiple-input multiple-output (MIMO) systems. Unlike the conventional maximum likelihood detection (MLD) method which needs the knowledge of channel state information (CSI) at the receiver, NMLD method has no need of CSI at either the transmitter or receiver. Afte...