Handover method from WCDMA to CDMA in multi-mode mobile phone

摘要

CDMA handover from the WCDMA multimode terminal using a modem, you can use an RF circuit to share the connection method are provided. During the call via the WCDMA modem judges need the CDMA handover. The WCDMA signal strength of the cell to which it belongs, or below a predetermined level, and it may determine a handover to the CDMA signal is necessary in the absence of the neighbor cell. If it is determined that CDMA handover is required, setting a RF transmission and reception in the CDMA mode, and thereby enable the CDMA modem attempts to acquire the pilot signal of the CDMA network. When the pilot signal of the CDMA network is obtained is set in a WCDMA mode RF transceiver and transmits the obtained information to the CDMA pilot WCDMA system through a WCDMA modem. Then, upon receiving the handover information from the WCDMA system through a WCDMA modem using the information set RF transceiver unit and the CDMA mode received by the CDMA modem then enters a CDMA call (Traffic) state. This information CDMA channel information, the frame offset information, code information, the initial power control information may be included. Then, the set of resources required for the call according to the CDMA, and to complete the handover process by releasing the call state of the WCDMA modem.