Patent ID: 7605753
Filing Date: 2009-10-20
Classification: G01S

Abstract:
1. Interference reduction circuitry comprising: a signal path to generate signals representing interference from transmissions of a transmitter, the signal path comprising a mixer to downconvert signals from the transmitter using a local oscillator (LO) associated with a positioning system receiver circuit and to generate in-band signals, an analog to digital converter to digitize the in-band signals and output a digitized signal, an adaptive filter to operate on the digitized signals to provide the signals representing interference; circuitry to remove a measured interference from received digital positioning system signals, the circuitry to remove comprising a summer to subtract the signals representing interference from the received digital positioning signals, the summer configured to provide an output signal to the adaptive filter and to the positioning system receiver circuit; and control circuitry coupled to the transmitter to detect when the transmitter is active by measuring one or more signals output by the transmitter or in response to a transmit-active signal, the control circuitry coupled to the adaptive filter to cause the filter to provide the signals representing interference when the transmitter is active and to cause the filter to refrain from providing the signals representing interference when the transmitter is not active.