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Algorithms of Controlling Radio Signal Power and Data Transmission Rate in Mobile Communication Systems


In mobile communication systems signal propagation channels between data receiver and transmitter are non-stationary. By this reason in order to maintain the required quality of the information transmission in cellular communication systems the transmitter power control is provided for depending on the radio channel parameters and noise level changeable in time.

One of main factors that decrease the operation efficiency of standard power control systems is the non-stationary of these systems. So if the estimate of the reception quality is generated at some moment of time then the required power at mobile station according to this estimate can be set only in some interval of time. The value of this interval is determined by a time signal structure and controlling commands. During the time of the said interval the channel parameters can be dramatically changed that will be especially noticeable under fast fading conditions. Then the obtained estimate will not characterize adequately the communi-cation quality at the moment setting the ordered power. It results in transmitter power control errors.

There is developed an algorithm of controlling radio signal power (while transmitting data from mobile station to base station), based on the prediction of the reception quality. The high efficiency of the developed algorithm is demonstrated using the mathematical simu-lation method. The developed algorithm provides the required reception quality at the mini-mum average power of the transmitted signal (as compared with the known algorithms) that allows increasing the communication systems capacity.

There is developed an algorithm of controlling data transmission rate for high-rate mobile communication system, based on the estimation of and prediction of the signal recep-tion quality. The algorithm sets the data transmission rate in transmitter to the maximum pos-sible under condition that the necessary communication quality is provided. One of main fac-tors that decrease the operation efficiency of data transmission rate control systems is the non-stationary of these systems. In the proposed algorithm the reception quality is predicted, which is used while selecting the data transmission rate.

Using the mathematical simulation method the proposed controlling data transmission rate algorithm is compared with alternative algorithms. Fading in channels is simulated ac-cording to Jakes model. The mobile user speed changes from 5 km/h to 100 km/h. It is ob-tained that the proposed algorithm provides the greatest real data transmission arte within a wide range of mobile user speeds. In this case the gain as compared with alternative algo-rithms under certain condition reaches 1.5ё2 times, that indicates the sufficiently high qual-ity of the developed algorithm and the possibility to use it in modern communication systems.


 

| About Us | Image Processing | Quasicoherent Reception |
| Multipath Reception | Smart Antenna Forward Link |
| Smart Antenna Reverse Link | Multi Antenna Reception and Transmission |
| Optimal balance of info & pilot signal components |
| Power and Data Rate Transmission Control | Multi-User Detection | Contact |