Transmission Power Allocation for Cognitive Radio System

摘要

PURPOSE: A transmission power assignment method in a CR(Cognitive Radio) system is provided to sense the frequency use state of a main user on the basis of the optimal carrier sensing threshold value of a sub user. CONSTITUTION: A sub user calculates the RSSI(Received Signal Strength Indication) of a main user for a quiet period(401). In case the calculated allowable maximum transmission power of the sub user entirely exists within the set minimum and maximum transmission power of the sub user, an optimal distance between the main user and the sub user is calculated(404,406). If not, the data transmission of the sub user is stopped(405). According to the optimal distance, RSSI is calculated.