Special call initiation in a direct sequence CDMA system

摘要

It aims at preferentially dealing with emergency communication etc. by a simple and effective method when emergency communication etc. isinitiated. In emergency situation, at a mobile station 200, a special call part 206 is switched from a normal mode to an emergency mode, and a mobile station side communication part 206 transmits a radio wave with a transmitted signal of high power (power spectrum density) at the center frequency f 0 of a carrier wave. A base station 100 receives the radio wave with the transmitted signal of high power (power spectrum density) at the center frequency f 0 of the carrier wave, from the mobile station 200 which output communication for emergency situation. The base station 100 outputs suppression signals for suppressing signal intensity to the other mobile stations. Only the mobile station 200 which transmitted the communication for emergency situation establishes a channel to the base station 100.