Dual-mode mobile phone and method of the same for inhibiting GSM/CDMA mutual interference
The present invention discloses a GSM/CDMA dual-mode mobile phone and method of the same for inhibiting a GC mutual interference, wherein the mobile phone comprises a dual-port antenna connected respectively with a duplexer and a GSM RF circuit and configured to access the signals of the GSM and the CDMA; a RF switch provided in the CDMA RF receiving circuit, wherein the RF switch is controlled by a GSM baseband chip and configured to cut off a CDMA signal (i.e., cutting off a receiving path of the CDMA) transmitted/received by the dual-port antenna when a GSM operational frequency and a CDMA operational frequency belong to close frequency band during a transmitting timeslot of the GSM, to enhance the isolation between a GSM signal and a CDMA signal. The present invention inhibits interference of GSM transmission with the CDMA receiving in the circuit, achieves high isolation, and also simplifies design of the antennas, lowers requirements of the double antennas on the appearance and volume of the overall machine, and improves the flexibility in the design of the dual-mode mobile phone.
1. A Global System for Mobile Communication GSM/Code Division Multiple Access CDMA dual-mode mobile phone, comprising: a CDMA RF circuit, a GSM RF circuit, a baseband circuit comprising a CDMA baseband chip and a GSM baseband chip, with the CDMA RF circuit comprising a CDMA RF receiving circuit, a CDMA RF transmitting circuit and a duplexer, the CDMA RF transmitting circuit being connected respectively with the CDMA baseband chip and the duplexer, the CDMA RF receiving circuit comprising a CDMA receiver, a receiving filter and a Low Noise Amplifier LNA which are sequentially connected, the CDMA receiver being connected with the CDMA baseband chip, the LNA being connected with the duplexer; the GSM RF circuit being connected with the GSM baseband chip; the mobile phone further comprising: a dual-port antenna, connected respectively with the duplexer and the GSM RF circuit, and configured to transmit/receive signals of the GSM and the CDMA; and RF switch(s), provided in the CDMA RF receiving circuit, wherein the RF switch(s) is controlled by the GSM baseband chip and configured to cut off, when the GSM RF and the CDMA RF work at near frequency during a transmitting timeslot of the GSM, CDMA signal(s) accessed by the dual-port antenna.
2. The GSM/CDMA dual-mode mobile phone according to claim 1 , wherein the dual-port antenna has a common pattern shared by a GSM antenna and a CDMA antenna with different feed connected to GSM or CDMA circuit.
3. The GSM/CDMA dual-mode mobile phone according to claim 2 , wherein the RF switch is located between the LNA and the duplexer, and configured to inhibit the strength of GSM signals entering the LNA.
4. The GSM/CDMA dual-mode mobile phone according to claim 2 , wherein the RF switch is located between the receiving filter and the LNA, and configured to inhibit non-linear product(s) generated by the LNA.
5. The GSM/CDMA dual-mode mobile phone according to claim 2 , wherein the RF switches are located between the LNA and the duplexer and located between the receiving filter and the LNA, and configured to inhibit the strength of GSM signals entering the LNA and non-linear product(s) generated by the LNA.
6. The GSM/CDMA dual-mode mobile phone according to claim 1 , characterized in that the RF switch(s) is/are single-stage or multi-stage switch(s).
7. A method for inhibiting a GC mutual interference of a GSM/CDMA dual-mode mobile phone, comprising the following steps: A. a GSM baseband chip initiating a dual-mode connected status or physical channel switching in the dual-mode connected status; B. the GSM baseband chip and a CDMA baseband chip respectively reading a GSM operational frequency and a CDMA operational frequency to be used, the GSM/CDMA dual-mode mobile phone judging whether they belong to close frequency band, wherein when yes, the GSM baseband chip initiates a switching function of a RF switch, it starts the dual-mode connected status or the channel switching in dual-mode connected status, and it goes to step C; otherwise, it is judged that whether the switching function of the RF switch has been initiated, wherein when yes, the GSM baseband chip sets the RF switch as an always on status, it starts the dual-mode connected status or the channel switching in dual-mode connected status, and the dual-mode connected status is ended; otherwise, the RF switch is kept as the always on status, it starts the dual-mode connected status or the channel switching in the dual-mode connected status, and the dual-mode connected status is ended; and C. ending the dual-mode connected status and setting the RF switch as the always on status.
8. The GSM/CDMA dual-mode mobile phone according to claim 2 , characterized in that the RF switch(s) is/are single-stage or multi-stage switch(s).
9. The GSM/CDMA dual-mode mobile phone according to claim 3 , characterized in that the RF switch(s) is/are single-stage or multi-stage switch(s).
10. The GSM/CDMA dual-mode mobile phone according to claim 4 , characterized in that the RF switch(s) is/are single-stage or multi-stage switch(s).
11. The GSM/CDMA dual-mode mobile phone according to claim 5 , characterized in that the RF switch(s) is/are single-stage or multi-stage switch(s).