Patent ID: 7218646

Claim:
A mobile radio communication system employing a CDMA (Code Division Multiple Access) method, comprising a transmitter configured to transmit via a period corresponding to a transmission of a specified number of frames, as a first transmission period, and to interleave data in said frames in bit units, and to successively transmit said frames in a unit of said first transmission period, in a normal mode and a receiver configured to receive the frames transmitted by said transmitter, wherein: said transmitter is further configured to transmit, to said receiver, a plurality of frames, in said first transmission period, in which non-transmission periods of ½ or less of the frame length are generated, by setting up said plurality of frames in compressed mode, in which the frames are compressed and disposed fixedly and not successively in said first transmission period, wherein each of the compressed frames is divided, and the divided compressed frame is assigned to the head and the end of the frame timing and data in the frame is interleaved in bit units, and said receiver is further configured to monitor a frequency component of a control data transmission channel having a second transmission period wherein said control data transmission channel is used in a mobile radio communication system which is different from said mobile radio communication system, in each of respective non-transmission periods which is generated in each of said plurality of frames, the second transmission period an integer multiple of said first transmission period.