To provide a mobile radio communication system such that even when UMTS (Universal Mobile Terrestrial communication System) and other system coexist, the frequency component of the other system can be observed securely from the UMTS and deterioration in interleaving performance of compressed mode frames during such observation can be suppressed.
The mobile radio communication system according to the present invention is a CDMA type mobile radio communication system which determines as a transmission period a period needed to transmit a specified number of frames and performs frame transmission in every transmission period, and includes a communication device which, for example, provides a plurality of non-transmission periods for each transmission period and uses the plurality of non-transmission periods to observe the frequency component of a control data transmission channel of the other mobile radio communication system.
YANO YASUHIRO
MURAI HIDESHI
