Robust and Simple Log-Likelihood Approximation for Receiver Design

Author(s):  
Yasser Mestrah ◽  
Anne Savard ◽  
Alban Goupil ◽  
Guillaume Gelle ◽  
Laurent Clavier
1978 ◽  
Vol 56 (2) ◽  
pp. 201-214 ◽  
Author(s):  
Gordon E. Kerr

Uncertainty analyses of sequences of actions by wild Dissosteira Carolina gave average uncertainties (Ĥ) of 2.4 male and 1.9 female bits/act in all contexts. Noninteracting males show low diversity and insignificant between-act predictability (log-likelihood approximation). Males interacting with males or females had higher uncertainties and significant between-act predictabilities. In male–male interactions, approaching and responding animals were nearly equivalent and Ĥ(I) was 2.02 bits/act for both. Three-way analysis showed that the effect of an animal's last act was slightly lower than that of the other animal's last act with some overlap. Bidirectional-communication and character analyses were also performed. Male–male interactions are neither stationary nor Markov processes. In male–female interactions, males had much higher uncertainties than females (2.25 versus 0.83 bits/act) and interanimal information transmission was very low.


2009 ◽  
Vol E92-B (1) ◽  
pp. 143-149
Author(s):  
Sen-Hung WANG ◽  
Chih-Peng LI ◽  
Chao-Tang YU ◽  
Jian-Ming HUANG ◽  
Chua-Chin WANG

Author(s):  
Russell Cheng

This book relies on maximum likelihood (ML) estimation of parameters. Asymptotic theory assumes regularity conditions hold when the ML estimator is consistent. Typically an additional third derivative condition is assumed to ensure that the ML estimator is also asymptotically normally distributed. Standard asymptotic results that then hold are summarized in this chapter; for example, the asymptotic variance of the ML estimator is then given by the Fisher information formula, and the log-likelihood ratio, the Wald and the score statistics for testing the statistical significance of parameter estimates are all asymptotically equivalent. Also, the useful profile log-likelihood then behaves exactly as a standard log-likelihood only in a parameter space of just one dimension. Further, the model can be reparametrized to make it locally orthogonal in the neighbourhood of the true parameter value. The large exponential family of models is briefly reviewed where a unified set of regular conditions can be obtained.


Author(s):  
Yi Zhang ◽  
Akash Doshi ◽  
Rob Liston ◽  
Wai-tian Tan ◽  
Xiaoqing Zhu ◽  
...  

Author(s):  
Victor Croisfelt Rodrigues ◽  
Abolfazl Amiri ◽  
Taufik Abrao ◽  
Elisabeth De Carvalho ◽  
Petar Popovski

Author(s):  
Stephan Schlupkothen ◽  
Gerd Ascheid

Abstract The localization of multiple wireless agents via, for example, distance and/or bearing measurements is challenging, particularly if relying on beacon-to-agent measurements alone is insufficient to guarantee accurate localization. In these cases, agent-to-agent measurements also need to be considered to improve the localization quality. In the context of particle filtering, the computational complexity of tracking many wireless agents is high when relying on conventional schemes. This is because in such schemes, all agents’ states are estimated simultaneously using a single filter. To overcome this problem, the concept of multiple particle filtering (MPF), in which an individual filter is used for each agent, has been proposed in the literature. However, due to the necessity of considering agent-to-agent measurements, additional effort is required to derive information on each individual filter from the available likelihoods. This is necessary because the distance and bearing measurements naturally depend on the states of two agents, which, in MPF, are estimated by two separate filters. Because the required likelihood cannot be analytically derived in general, an approximation is needed. To this end, this work extends current state-of-the-art likelihood approximation techniques based on Gaussian approximation under the assumption that the number of agents to be tracked is fixed and known. Moreover, a novel likelihood approximation method is proposed that enables efficient and accurate tracking. The simulations show that the proposed method achieves up to 22% higher accuracy with the same computational complexity as that of existing methods. Thus, efficient and accurate tracking of wireless agents is achieved.


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