Signal to interference power ratio measuring apparatus and signal to interference power ratio measuring method as well as transmission power controlling method under CDMA communication system

摘要

The invention provides a technique for measurement of a signal to interference power ratio wherein an SIR can be measured with a higher degree of accuracy without being influenced by a fast fading environment or an inter-station interference or noise environment. A signal to interference power ratio measuring apparatus includes a plurality of interference replica signal production sections for performing de-spread processing for input signals originating from a received signal, performing temporary decision of information symbols regarding the input signals, performing spread processing again for the input signals and outputting resulting signals as interference replica signals, a plurality of subtractors for subtracting the interference replica signals from the received signal, an interference power detection section for detecting interference power information, a signal power detection section for detecting signal power information, and a signal to interference power ratio calculation section for calculating signal to interference power ratios from the interference power information and the signal power information.