Optimization of Idle-Mode Receiver Measurements in WCDMA

Peter Mörking

Handledare: Jan Holst

Centre for Mathematical Sciences
Mathematical Statistics
Lund Institute of Technology,
Lund University,
2002:E2

Abstract

In mobile communications certain demands on message-receiving performance are put forward by

the operators. Also, demands from the users concerning stand-by time and active talking time are important for the manufacturers. However, these two demands are contradictory. This thesis is concerned with the task of optimizing the receiver measurements in a WCDMA receiver, although still fulfilling the demands set by operators. The procedure considered is one of the major processes in idle mode: The paging procedure. This is the procedure, which tells the phone when to go to active mode.

The operators set demands on low bit error rates in the data detection. To get low error ratios

extensive measurements have to be performed. These measurements affect the battery power consumption in the phone and hence the stand-by time is also affected. The purpose of this thesis is to investigate the paging procedure to see how the stand-by time can be maximized although still fulfilling the demands from operators. This is done by finding a good relation between the number of false alarms and the number of data needed for channel estimation and paging detection.

A theoretical model of the communication channel between base stations and mobile phones has

been developed as well as a model for the power consumption in the phone in idle mode.

The results show that between one third and half of the power used today would be sufficient for good

performance.