Title :
Outer-Loop Power Control in a live UMTS network: Measurement, analysis and improvements
Author :
Laner, Markus ; Svoboda, Philipp ; Rupp, Markus
Author_Institution :
Inst. of Commun. & Radio-Freq. Eng., Vienna Univ. of Technol., Vienna, Austria
Abstract :
The Outer Loop Power Control (OLPC) in WCDMA systems allows to achieve a defined Quality of Service (QoS) for every link. This reduces resources and interference, hence, increases the system-wide throughput. In this paper we present uplink OLPC related large-scale measurements, performed on live Iub-interfaces. Evaluations of the actual implemented algorithm show that it converges slowly; the reason being that the QoS is estimated by CRC. As the uncoded Bit Error Ratio (BER) holds information about the QoS, this parameter can be used to increase convergence speed of the OLPC. We present a statistical model of the control path of the OLPC which takes the uncoded BER information into account. Additionally, we propose a new OLPC algorithm that shows fast convergence in simulations, resulting in a reduction of 0.2 dB to 1 dB of the mean required signal-to-interference ratio, depending on the user mobility.
Keywords :
3G mobile communication; broadband networks; code division multiple access; error statistics; interference suppression; power control; quality of service; radio links; BER; QoS; UMTS network; WCDMA systems; bit error ratio; interference reduction; large-scale measurements; outer-loop power control; quality of service; signal-to-interference ratio; user mobility; 3G mobile communication; Bit error rate; Convergence; Interference; Large-scale systems; Multiaccess communication; Power control; Power measurement; Quality of service; Throughput;
Conference_Titel :
Communications, Control and Signal Processing (ISCCSP), 2010 4th International Symposium on
Conference_Location :
Limassol
Print_ISBN :
978-1-4244-6285-8
DOI :
10.1109/ISCCSP.2010.5463465