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Call detail records (CDRs) collected at telecommunication networks have been well studied to reveal human behaviors such as voice service usage, contact regularities and mobility patterns. With the advances in big data technology, carriers can now collect, store and analyze more data, such as records of user mobile web activities, at scales much larger than CDRs. In this paper, we study 14 features...
Determining the best fit statistical distribution with parameters for a dataset is a common task in many datadriven applications. Existing approaches to the problem usually combine parameter estimation and goodness-of-fit (GOF) tests or statistics, fitting the dataset to each of the candidate distributions and choosing the best one based on the GOF. With big data technologies collecting and storing...
As the usage of wireless devices rapidly increases, mobile phones have become an important aid for people to maintain social relationships. Analysis on cellular networks through mobile communication records, especially when such records contain temporal and spatial information, can potentially unveil fundamental laws that govern the dynamics of social networks. In this paper, we use call detail records...
The diversity gain function is a unified metric for the asymptotic error performance of wireless communication systems. In this correspondence, we propose a theorem that relates the diversity gain function and the coding gain to the probability density function of the instantaneous signal-to-noise ratio (SNR) at the origin. It provides a general framework for analyzing the asymptotic reliability of...
Step size and tap length play critical roles in balancing the complexity and steady-state performance of an adaptive filter. For an impulse response with an exponential power decay profile, which models a wide range of practical systems, such as an acoustic echo path, this paper proposes a new variable step-size and tap-length least mean square (LMS) algorithm. In each iteration, the optimal step-size...
In the literature, peak-to-average power ratio (PAR) is often used as an indicator for the dynamic range of OFDM signals. PAR is an extreme value statistic and can present an overly pessimistic view of the signal. Instantaneous-to-average power ratio (IAR), on the other hand, reflects more accurately the characteristics of the sample population. In this paper, we show that depending on whether clipping...
This paper aims at double-talk detector design for acoustic echo cancellers (AECs) enabling transmission of speech signals in stereo. A reliable double-talk detector (DTD) is often a necessary requirement for AECs. Its role is to freeze the adaptation of the AEC filter when near-end speech is present in order to avoid divergence of the adaptive algorithm. The existing DTDs based on the normalized...
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