A new cognitive mobile communication system

A new cognitive mobile communication system (CCMCS) is proposed in this paper, which can utilize the unlicensed frequency sufficiently, protect the investment of networks existed and support its evolution. Through the effective application of variable-band OFDM and multiband OFDM, the system can connect several narrowbands into a wideband, and support high speed data transmit. Synchronization to the CCMCS is realized if a MT can synchronize to one of the systems existed. Besides, database supplies a convenient way to obtain suitable access schemes.