Sirf Technology, Inc.

Csr Technology Inc.

Navcom Technology, Inc.

Csr Technology Holdings Inc.

Western Multiplex

Donald Leimer

Mark Alan Sturza

Sanjai Kohli

Steven A Gronemeyer

Charles Robert Cahn

Richard Kai-Tuen Woo

Sharath Ananth

Jalal Alisobhani

Mark Philip Kaplan

A method is provided for decimating a digital signal by a factor of M and matching it to a desired channel bandwidth. The method applies the digital signal input samples to a (M&#x2212;1) stage tapped delay line, downsamples the input samples and the output samples of each tapped delay line stage by a factor of M, and applies each of the M downsampled sample value streams to M allpass IIR filters, respectively. The M allpass IIR filtered sample streams are then summed and scaled by a factor of 1/M. The result can then be filtered by a digital channel filter.

Multi-standard multi-rate filter

A wireless device including a transceiver that utilizes a power supply is described. The wireless device includes a Global Positioning System ('GPS') section having a plurality of GPS subsystems and a power controller in signal communication with the power supply and GPS section, wherein the power controller is configured to selectively power each GPS subsystem from the plurality of GPS subsystems.

System and method for operating a GPS device in a micro power mode

A method is provided for decimating a digital signal by a factor of M and matching it to a desired channel bandwidth. The method applies the digital signal input samples to a (M-1) stage tapped delay line, downsamples the input samples and the output samples of each tapped delay line stage by a factor of M, and applies each of the M downsampled sample value streams to M allpass IIR filters, respectively. The M allpass IIR filtered sample streams are then summed and scaled by a factor of 1/M. The result can then be filtered by a digital channel filter.

A method for estimating a Doppler spread and a signal-to-noise ratio of a received signal includes: (a) calculating one or more functions of a carrier component of the received signal at a first time point relative to a pilot signal embedded in the received signal; (b) Calculating the one or more functions of the carrier component of the received signal at a second time point relative to the pilot signal; (c) repeating steps (a) and (b) over multiple time periods, each time period being substantially longer than the second time, and accumulating the one or more functions for the first time points and the second time points; and (d) Deriving the Doppler spread and the signal-to-noise ration based on the accumulated one or more functions calculated at the first and second time points. In one embodiment, the first time point is substantially closer to the pilot signal than the second time point. The first time point is one symbol interval from the pilot signal.

Method of estimating doppler spread and signal-to-noise ratio of a received signal

A frequency domain diversity DVB receiver device includes multiple antenna ports for receiving radio signals, and radio signal processing circuits connected to the antenna ports that convert the received radio signals into digital samples. The digital samples from the different antenna ports time-share a front-end processor which processes the digital samples to provide time-domain symbols. The time-domain symbols are stored in time-domain symbol buffers according to which of the antenna ports the time-domain symbols are received. A fast fourier transform circuit then retrieves the time-domain symbols and converts them frequency-domain symbols, which are then stored one or more frequency-domain symbol buffers according to the antenna ports the corresponding radio signals are received. A diversity processor which combines the frequency-domain symbols from the frequency-domain symbol buffers.

Memory efficient OFDM channel estimation and frequency domain diversity processing

An adaptive antenna array employs selective polarization nulling and spatial nulling to receive desired signals in the presence of jamming signals. The desired signals have the same circular polarization, and the array includes at least one antenna element having an opposite circular polarization to null jamming signals having an opposite circular polarization. A gain pattern for the array is selected to minimize signals having the same circular, or linear, polarization. The gain pattern is computed based on jamming signals received when no desired signals are transmitted, or selected based on measured desired signals.

Adaptive array antenna nulling

A communication device includes a transmitter and receiver. The transmitter includes an M-ary encoder configured to generate an M&minus;1 number of distinctive symbols each comprising k bits. M is equal to 2 and k is a positive integer. The transmitter also includes a code generator configured to produce spread spectrum codeword sequences based on the symbols generated by the M-ary encoder and based on a first and a second Gold code polynomials. The transmitter sends a radio signal based on the spread spectrum codeword sequences. The receiver is configured to receive the radio signal. The receiver includes a first shift register configured to receive an input signal generated based on the received radio signal and a second shift register configured to receive and circularly shift a locally generated codeword sequence that is identical to the codeword sequence used to encode the symbols. The receiver also includes an accumulator coupled to the first and second shift registers and configured to multiply and accumulate stored values in the first and second shift registers each time the second shift register is circularly shifted and a selecting device coupled to the accumulator and configured to identify one symbol from the plurality of symbols based on outputs from the accumulator. A method corresponding to the device is also provided.

Spread-spectrum GMSK/M-ary radio

A Global Positioning System receiver incorporating a method of reducing the effect of common mode oscillator phase noise. Oscillator phase noise in the receiver is a basic limitation on narrowing the carrier tracking loop bandwidth and, therefore, on the achievable carrier-track C/No for a GPS receiver tracking a single satellite signal. However, when receiving several satellite signals, the receiver phase noise is common to all tracking loops and, in principle, can be removed by a common-mode rejection scheme. The phase noise contributed by the satellites is negligible in comparison with the phase noise contributed by the receiver's oscillator; hence, the common-mode rejection is improved by tracking multiple satellite signals.

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Rancho Palos Verdes, CA, United States of America

Donald Leimer