Patent ID: 9025554
Filing Date: 2015-05-05
Classification: H04B,H04L,H04W

Abstract:
1. A wireless base station, comprising: a resource determiner that determines at least a part within any downlink subframe as a first resource for transmitting downlink user data to a wireless terminal and determines at least a part of an uplink part within a switch subframe or a part of an uplink subframe as a second resource for said wireless terminal to periodically transmit a sounding reference signal; a resource notifier that notifies said wireless terminal of said second resource; a transmission path state estimator that estimates a state of a transmission path to said wireless terminal based on a reference signal included in uplink user data received from said wireless terminal when a re-sending request is received after transmission of said sounding reference signal is stopped; and a transmitter that forms directivity of a plurality of antennas based on the estimated state of the transmission path and transmits said downlink user data through said first resource.