Sirf Technology, Inc.

Sirf Technology Holdings, Inc.

Centrality Communications, Inc.

Sirf Technology Holdihgs, Inc.

David Wang

Chi-Shin Wang

Jun Mo

Zongde Qiu

Lei Dong

Henry Leung

Wentao Zhang

The present invention provides systems and methods for reducing the 'cold start' TTFF of navigation receivers. The systems and methods receive geographical information from a user, such as the nearest city, state or country, and use this geographical information to approximate the position of the receiver. The systems and methods then make use of the approximate position to reduce the 'cold start' TTFF. In an embodiment, the approximate position of the receiver is determined from a co-ordinate database in the receiver based on the geographical information provided by the user. In another embodiment, a user provides geographical information to the receiver through a displayed map with several stages of zooming capability.

Method of enhanced cold start and associated user interface for navigational receivers

Flexible mounting devices for navigational/entertainment displays, especially for in-vehicle use, are described herein. In an embodiment, the flexible mounting device comprises a flexible gooseneck, a magnetic base magnetically attached to a front end of the gooseneck for holding a display, and a windshield suction attached to a back end of the gooseneck for providing windshield support from the rear by suctioning to the windshield of a vehicle. In another embodiment, the flexible mounting device comprises a flexible neck, which may be firmly attached to the dashboard of a vehicle with a sticky gel pad. The mounting device also comprises a counter weight attached to a back end of the flexible neck. The display is fixed to a front end of the flexible neck such that the display protrudes beyond the dashboard. The counter weight at the back end of the flexible neck counter balances the weight of the display at the front end, and thereby helps to provide a stable support.

Flexible mounting device for video/map display

The present invention provides methods and systems that enable a mobile navigation receiver to accurately determine its trajectory with non-current ephemeris in stand-alone mode. In an embodiment, the receiver computes the position for the same location using non-current ephemeris and current ephemeris at different time instances. The receiver then determines a position correction by finding the difference between these two computed positions, and applies this correction to the trajectory generated with non-current ephemeris to obtain a more accurate trajectory. In another embodiment, the receiver computes an initial position of the receiver using non-current ephemeris and finds the difference between the computed initial position and an accurate approximation of the initial position. The receiver then shifts the subsequent receiver trajectory computed using non-current ephemeris by the difference to obtain a more accurate trajectory.

Navigation signal receiver trajectory determination

The present invention provides methods and systems for keeping the ephemeris in a navigational receiver current to achieve fast TTFF without the need for connecting to an aiding network or remote server. In an embodiment, the receiver keeps the ephemeris current by downloading the ephemeris in the background. In the preferred embodiment, the receiver uses a background sleep/wake up process to download current ephemeris with minimal power drain. In this embodiment, the receiver alternates between a sleep mode and a wake up mode. During the wake up mode, the receiver attempts to download current ephemeris. The receiver then goes back to the sleep mode until the next wake up to conserve power. The receiver may wake up from the sleep mode to download the ephemeris when the stored ephemeris is no longer current or the ephemeris broadcasted from a satellite has been updated or based on receiver usage patterns.

Growing community of inventors

Belmont, CA, United States of America

David Wang