Patent ID: 8588835
Filing Date: 2013-11-19
Classification: H04W

Abstract:
1. A base station apparatus for a mobile communication system, comprising: a collection unit configured to collect measured data from one or more user equipment terminals with respect to each direction of arrival, the measured data including at least quality information of a downlink signal; a conversion unit configured to convert the measured data into an evaluation value in accordance with a predetermined evaluation function; a deriving unit configured to derive a weight update amount based on an angular distribution of a plurality of evaluation values, the weight update amount determining directivity; and a transmission unit configured to transmit a downlink signal weighted based on the weight update amount, wherein the predetermined evaluation function increases or decreases depending on a received signal level of the downlink signal, wherein in a case where the received signal level of the downlink signal is in a predetermined range, the predetermined evaluation function is a positive value when the received signal level of the downlink signal is less than a predetermined first threshold value and the predetermined evaluation function is a negative value or 0 when the received signal level of the downlink signal is greater than or equal to the predetermined first threshold value, wherein in a case where the received signal level of the downlink signal is greater than or equal to the predetermined first threshold value, the predetermined threshold evaluation function is 0 when a ratio of a desired signal to power to an undesired signal power is greater than or equal to a predetermined second threshold value and the predetermined evaluation function is a negative value when the ratio of the desired signal power to the undesired signal power is less than the predetermined second threshold value, and wherein transmission power is increased when the predetermined evaluation function is a positive value, transmission power is decreased when the predetermined evaluation function is a negative value, and transmission power is maintained when the predetermined evaluation function is 0.