Invention Grant
US08355752B2 Using LO shifting to prevent a local transceiver from interfering with an FM radio
有权
使用LO移位来防止本地收发器干扰FM收音机
- Patent Title: Using LO shifting to prevent a local transceiver from interfering with an FM radio
- Patent Title (中): 使用LO移位来防止本地收发器干扰FM收音机
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Application No.: US12610600Application Date: 2009-11-02
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Publication No.: US08355752B2Publication Date: 2013-01-15
- Inventor: Pushp Trikha , Luca Blessent , Xiaoyong Li , Rahul A. Apte
- Applicant: Pushp Trikha , Luca Blessent , Xiaoyong Li , Rahul A. Apte
- Applicant Address: US CA San Diego
- Assignee: QUALCOMM Incorporated
- Current Assignee: QUALCOMM Incorporated
- Current Assignee Address: US CA San Diego
- Agent Eric Ho
- Main IPC: H04M1/00
- IPC: H04M1/00 ; H04B1/16 ; H04B7/00 ; H04B1/10

Abstract:
A cellular telephone includes cellular telephone circuitry and an FM receiver. An FM signal being received is downconverted by a mixer. The downconverted signal is processed to generate an FM signal that is supplied to a digital IF filter. If a blocker emitted by the cellular telephone circuitry would interfere with receiving of the FM signal due to interaction of an LO harmonic with the blocker if a conventional LO frequency were used, then a different LO frequency is used. Subsequent processing of the downconverted FM signal (for example, by a digital complex conjugate selector and an IF rotator) results in the signal supplied to the digital IF filter having the same center frequency as the digital IF filter despite the use of the different LO frequency. In some embodiments, the LO is shifted by different amounts depending on cellular telephone mode and on the FM signal.
Public/Granted literature
- US20110009161A1 USING LO SHIFTING TO PREVENT A LOCAL TRANSCEIVER FROM INTERFERING WITH AN FM RADIO Public/Granted day:2011-01-13
Information query