Avoiding interference to a GPS receiver from wireless transmissions by time multiplexing GPS reception

• US 6,825,802 B2
• Filed: 11/18/2002
• Issued: 11/30/2004
• Est. Priority Date: 11/18/2002
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: RF Micro Devices Incorporated (Qorvo, Inc.)
• Inventors: Warloe, Andreas
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US10/298,414
• Publication Number:
  US 20040095273A1
• Time in Patent Office: 743 Days
• Field of Search: 342/357.1, 342/357.12, 342/357.15, 375/150
• US Class Current: 342/357.59
• CPC Class Codes: G01S 19/215 issues related to spoofing
• CPC Class Codes: G01S 19/30 code related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: H04B 1/7097 Interference-related aspects
• CPC Class Codes: H04B 2201/70715 with application-specific features
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04K 3/224 with countermeasures at transmission and/or reception of the jammed signal, e.g. stopping operation of transmitter or receiver, nulling or enhancing transmitted power in direction of or at frequency of jammer
• CPC Class Codes: H04K 3/90 related to allowing or preventing navigation or positioning, e.g. GPS

Abstract

The jammer response circuitry of the present invention operates to control correlation circuitry in a GPS receiver based on an occurrence of a transmission from a wireless transmitter, thereby avoiding performance degradation in th GPS receiver due to interference caused by the transmission. In general, the jammer response circuitry activates a control signal during the transmission, thereby temporarily stopping the operation of the correlation circuitry. More particularly, the accumulation of results of a correlation of a received signal with a generated frequency and a generated code having numerous time offsets is temporarily stopped when the control signal is activated and resumes operation when the control signal is deactivated.

Claims

1. A GPS receiver comprising:

correlation circuitry adapted to receive a control signal and provide data corresponding to a correlation of a signal with a generated frequency and a generated code at a plurality of time offsets based on said control signal, wherein said control signal is based on an occurrence of a transmission of an interference signal; and

circuitry adapted to provide said generated frequency and said generated code at said plurality of time offsets to said correlation circuitry;

wherein said correlation circuitry comprises accumulation circuitry adapted to accumulate results of said correlation based on said control signal to provide said data, stop accumulation of said correlation when said control signal is in a first state, and resume accumulation when said control is in a second state.

2. The GPS receiver of claim 1 wherein said transmission is from an associated wireless communications device, farther wherein said interference signal is a communications signal transmitted from said wireless communications device.

3. The GPS receiver of claim 1 further comprising jammer response circuitry adapted to provide said control signal to said correlation circuitry based on the occurrence of the transmission of the interference signal.

4. The GPS receiver of claim 3 wherein said jammer response circuitry activates said control signal during said transmission and deactivates said control signal when said transmission is complete.

5. The GPS receiver of claim 3 wherein said jammer response circuitry is further adapted to repeatedly provide said control signal based on a wireless communications device repeatedly transmitting said interference signal, further wherein said interference signal is a communications signal.

6. The GPS receiver of claim 1 wherein said data is constant while said control signal is active.

7. A system comprising:

a receiver frontend adapted to receive a global positioning system (GPS) signal and provide a baseband signal based on said radio-frequency signal;

correlation circuitry adapted to receive a control signal and provide data corresponding to a correlation of said baseband signal with a frequency and a generated code at a plurality of time offsets based on said control signal, said correlation circuitry comprising accumulation circuitry adapted to accumulate results of said correlation based on said control signal to provide said data and further adapted to stop accumulation of said correlation when said control signal is in a first state and resume accumulation when said control signal is in a second state;

circuitry adapted to provide said generated frequency and said generated code at said plurality of time offsets to said correlation circuitry;

jammer response circuitry adapted to provide said control signal to said correlation circuitry based on an occurrence of a transmission of a communications signal; and

wireless transmission circuitry adapted to transmit said communications signal, wherein said communications signal is much stronger than said GPS signal.

8. The GPS receiver of claim 7 wherein said data is constant while said control signal is active.

9. The GPS receiver of claim 7 wherein said jammer response circuitry activates said control signal during said transmission and deactivates said control signal when said transmission is complete.