Patent ID: 8111683
Filing Date: 2012-02-07
Classification: H04L,H04W

Abstract:
1. A base station constituting a cellular radio communication system, the base station comprising: an antenna for communicating radio frequency (RF) signals with a mobile station; a front end unit for converting the RF signal received by the antenna into an uplink baseband signal, and converting a downlink baseband signal to be transmitted to the mobile station into an RF signal to output the RF signal to the antenna; a demodulation processing unit for demodulating the uplink baseband signal outputted from the front end unit; a modulation processing unit for multiplexing a control signal and a downlink data signal to be transmitted to the mobile station and converting into a downlink baseband signal to output the downlink baseband signal to the front end unit; an uplink-timing detector for detecting a reception timing gap of an uplink signal transmitted by the mobile station, from the uplink baseband signal outputted from the front end unit; a time alignment (TA) control signal generator for generating a TA control signal based on the uplink signal reception timing gap detected by the uplink-timing detector and outputting the TA control signal to the modulation processing unit; a timing-out detector for generating a TA-range-out signal indicating whether the mobile station is in an out of normal TA control range state or not, according to a result of a comparison between the uplink signal reception timing gap outputted from the uplink-timing detector and a predetermined threshold; and a transmission condition change signal generator which generates a transmission condition change signal for changing a transmission condition of the uplink signal in the mobile station based on the TA-range-out signal outputted from the timing-out detector and outputs the transmission condition change signal as the control signal to the modulation processing unit, wherein the downlink baseband signal outputted from the modulation processing unit to the front end unit includes the transmission condition change signal and the TA control signal.