Radio channel state prediction by Kalman filter

In this article there is the description Kalman filter using as a radio channel state predictor. Simulator of prediction has been created in MATLAB environment and it is capable to simulate the prediction of radio signal envelope by Clark’s model of radio channel, which is implemented to the simulator. Simulations were realized for prediction range 0.41 ms and 6.24 ms and as comparing criterion we used the prediction error. It is clear from simulations, that with the duration of prediction the prediction error is enlarging, which may cause the erroneous decision of adaptation algorithms

Mathematical models of MIMO channel

In this contribution, we try to resolve the problem with multipath MIMO channel in wireless environment. To understand the environment, where multipath signal is transported, theoretical models will be applied. We will take a look on theoretical models and results reached in mathematical programmable language MATLAB. Results will be shown on graphs at the end of this paper

WCDMA mobile radio network simulator with hybrid link adaptation

The main aim of this article is the description of the mobile radio network model, which is used for simulation of authentic conditions in mobile radio network and supports several link adaptation algorithms. Algorithms were designed to increase efficiency of data transmission between user equipment and base station (uplink). The most important property of the model is its ability to simulate several radio cells (base stations) and their mutual interactions. The model is created on the basic principles of UMTS network and takes into account parameters of real mobile radio networks

Data rates in EDGE standard

Several modulations and coding schemes are used to reach the effective radio resources usage in EDGE networks. The review describes these methods together with base stations interference and variable quality of signal impact to data rate and used coding scheme

Power control delay in WCDMA mobile radio networks

This article presents the basic theory of power control and deals with the mutual interference among mobile subscribers (basic stations) in uplink (downlink). Considering the SIR requirements, each transmitter in the WCDMA network have to use minimum output power, which is necessary to span channel fading. Accurate transmitter power level can be achieved by using optional power control loops, which send appropriate Transmitter Power Control (TPC) commands through dedicated feedback channel. Effect of power control commands delay in the WCDMA mobile radio network are presented by uplink simulations results. Presented power control loop is based on the standardized algorithm. The investigation of the influence of TPC commands delay in the case of high speed mobile subscriber helps in designing the optional link adaptation algorithm

Complex simulation model of mobile fading channel

In the mobile communication environment the mobile channel is the main limiting obstacle to reach the best performance of wireless system. Modeling of the radio channel consists of two basic fading mechanisms - Long-term fading and Short-term fading. The contribution deals with simulation of complex mobile radio channel, which is the channel with all fading components. Simulation model is based on Clarke-Gans theoretical model for fading channel and is developed in MATLAB environment. Simulation results have shown very good coincidence with theory. This model was developed for hybrid adaptation 3G uplink simulator (described in this issue) during the research project VEGA - 1/0140/03

Adaptation methods in mobile communication networks

Adaptation methods are the main tool for transmission rate maximization through the mobile channel and today the great attention is directed to them not only in theoretical domain but in standardization process, too. The review of adaptation methods for system and technical parameters of mobile cellular networks (2.5G and 3G) is carricd out

Pulse response measurement and processing by six-port reflectometr

In this paper the pulse response estimation of radio channel by Six-port reflectometer (SPR) is described. The measurement of pulse response is in real time, with baseband conversion and without demodulation. This system is simple, small, exact and inexpensive. In the present, it is insisted on signal processing in real time. In present time it is requested to use faster systems of signal processing, so the using of high performance digital devices is needed. Pulse response of radio channel, six-port reflectometer and radio channel are simulated in program language Delphi 7. In this work the pulse response measurement of MIMO radio channel by Six-port reflectometer technique. A pulse response matrix, Rayleigh fading in the radio channel, SPR technology, AWGN radio channel has been simulated in program language Delphi 7