On the importance of error memory in UMTS radio channel emulation using hidden Markov models (HMM)

Abstract

The possibility to change data rate in 10 milliseconds is one of the innovative features of the Universal Mobile Telecommunications System (UMTS). This change results in a different mobile channel with different burst error characteristics that can be modelled and its effects can be emulated by Hidden Markov Models (HMM) which are computationally more efficient than waveform level models. Thus the data rate change in the wideband CDMA (WCDMA) channel supposes to change the HMM. This change from one HMM to another can be performed considering the number of errors in the last frame or not. In this paper the impact of error memory when the channel emulated by HMM change, is presented'.

Electromagnetic Interference Simulation of a Cell Phone in an Aircraft System Using Domain Decomposition Method

“…The establishment of simple models with the ability to capture the most significant statistical properties of the error processes is an issue of utmost importance and the use of Markov Models (MM) and Hidden Markov Models (HMM) has been frequently claimed in this context. Hidden Markov Models have been successfully applied to satellite and wireless communications [1]- [5], [13]. Besides, simple HMM such as the Gilbert-Elliot model have been shown to be useful for performance analysis, not only to evaluate the impact of errors generated in the physical layer, but also in regard of the errors produced in higher layers [1].…”

A Measurement Based Model for UMTS DL DCH Dynamic Bearer Type Switching

“…Due to the fact that the error characteristics are different in each bearer a better representation of the channel can be reached by including bearer switching in the error model which is done e.g. in [4] based on simulations only. Our approach in this work is to develop a model for dynamic bearer type switching based on measurements in live UMTS networks within typical mobility scenarios for using UMTS services.…”