In this paper, we evaluate performance of model adaptation by the previously proposed HMM decomposition method[1] on telephone speech recognition. The HMM decomposition method separates a composed HMM into a known phoneme HMM and an unknown noise and channel HMM by maximum likelihood (ML) estimation of the HMM parameters. A transfer function (telephone channel) HMM is estimated using adaptation...

Sometimes called radio in the loop (RITL) or fixed-radio access (FRA), wireless local loop (WLL) is a system that connects subscribers to the public switched telephone network (PSTN) using radio signals as a substitute for copper for all or part of the connection between the subscriber and the switch. This includes cordless access systems, proprietary fixed radio access, and fixed cellular syst...

RE: " CELLULAR TELEPHONE USE AND RISK OF ACOUSTIC NEUROMA " Christensen et al. (1) recently presented results on the use of cellular telephones and the risk for acoustic neuroma. However, in our opinion, several issues need to be clarified in the paper. Our main concern is that the study did not take into account exposures from cordless phones, and associations specific for ever use of analog o...

A Philips low voltage high performance monolithic FM/IF system, the SA639 is introduced to meet the increasing demand for high speed digital wireless PCS applications. In order to assist the system design, a SA639-based performance evaluation board has been developed according to the Digital European Cordless Telephone (DECT) specifications. This application note presents a detailed description...

In this paper a novel frequency hopping algorithm is introduced, which is tailored for use in a Cordless Telephone System (CTS) that relies on total frequency hopping to use the same frequency band as a GSM system.The algorithm was designed with the goal of minimising the interference between different CTS-units and between the CTS and the overlay GSM network, taking into account standard GSM i...

Wireless Local Loop A.Balaji , Timothy A. Gonsalves , R. Kumar Dept. of Computer Science and Engineering Indian Institute of Technology Madras Chennai 600 036 Email: {abala, tag, rkumar}@tenet.res.in September 1998 Abstract The traditional wired local loop used to connect each telephone subscriber to the nearest exchange is expensive and unreliable. Wireless Local Loop (WLL) systems largely eli...