SiRF Technology Holdings, Inc.

About: SiRF Technology Holdings, Inc. is a based out in . It is known for research contribution in the topics: Signal & Assisted GPS. The organization has 215 authors who have published 265 publications receiving 8686 citations.

Multi-mode global positioning system for use with wireless networks

Abstract: The present invention discloses a GPS system (100) that can operate in different modes depending on the network facilities and bandwidth available, the GPS information (114) that can be acquired, or user or system requirements. The modes comprise standalone mode, where a mobile communications device (104) computes the position of the device, an autonomous mode, where the mobile communications device (104) transmits the computed position to a server (108), application (110), or PSAP (112) in a communications network, a network aided mode, where the network aides the mobile communications device (104) in determining the position of the device, a network based mode, and other modes.

Information transfer in a multi-mode global positioning system used with wireless networks

Abstract: The present invention discloses a GPS system that can operate in different modes depending on the network facilities and bandwidth available, the GPS information that can be acquired, or user or system requirements. The modes comprise standalone mode, where a mobile communications device computes the position of the device, an autonomous mode, where the mobile communications device transmits the computed position to a server, application, or PSAP in a communications network, a network aided mode, where the network aides the mobile communications device in determining the position of the device, a network based mode, and other modes.

Parametric adaptive matched filter for airborne radar applications

Abstract: The parametric adaptive matched filter (PAMF) for space-time adaptive processing (STAP) is introduced via the matched filter (MF), multichannel linear prediction, and the multichannel LDU decomposition. Two alternative algorithmic implementations of the PAMF are discussed. Issues considered include sample training data size and constant false alarm rate (CFAR). Detection test statistics are estimated for airborne phased array radar measurements, and probability of detection is estimated using simulated phased array radar data for airborne surveillance radar scenarios. For large sample sizes, the PAMF performs close to the MF; performance degrades slightly for small sample sizes. In both sample size ranges, the PAMF is tolerant to targets present in the training set.

Triple multiplexing spread spectrum receiver

Abstract: A spread spectrum receiver processes signals from a plurality of sources modulated by different spread spectrum codes by sampling the signals as received to produce an integer series of sampling segments at a sampling rate at least twice a chip rate of the codes, each sampling segment containing an integer number of bits representing a fraction of a chip of the codes, time division multiplexing each sample segment into a number of channels, correlating the bits in each sample segment in each channel in parallel with a source specific series of locally generated sequential code samples differing by one bit, summing each parallel correlation, and accumulating the summed parallel correlations for each code sample in each channel at a rate at least equal to the chip rate to derive data related to each of the sources.

Apparatus for stacking semiconductor chips

Abstract: A multi-chip memory module comprises multiple standard, surface-mount-type memory chips stacked on top of each other, and a pair of printed circuit boards mounted on opposite sides of the memory chips to electrically interconnect the memory chips. Each printed circuit board has vias that are positioned to form multiple rows, with each row of vias used to connect the printed circuit board to a respective memory chip. The vias falling along the bottom-most row of each printed circuit board are also exposed and are used to surface mount the multi-chip module to pads of a memory board.