| Patent application number | Description | Published |
|---|
| 20090102706 | Satellite interference canceling - A satellite interference canceling system cancels the interference between two or more signals received by a satellite receiver. The signals can be two signals experiencing cross polarization interference or signals that experience interference from other satellite signals. Gain and phase are applied to the received signals and then combined with the other signals to result in cancellation by subtraction. The gain and phase values needed to cancel the interference are derived from measurements of carrier-to-noise ratio (C/N) as an indication of the interference level. The C/N can be measured in the set-top box indoor unit. Coherency restoration is performed in receivers that downconvert the signals before performing interference cancellation. | 04-23-2009 |
| 20090290659 | Channel stacking system and method of operation - A channel stacking system includes first and second downconverting stages, first and second analog to digital converters, and a digital switching and signal processor. The first downconverting stage includes a first downconverter circuit having an input for receiving a first RF input signal which includes a multitude of first channels. The first downconverter circuit frequency downconverts the first RF input signal to a first IF signal which includes the multitude of first channels. The first analog-to-digital converter converts the first IF signal to a first digital IF signal. The second downconverter stage includes a second downconverter circuit having an input for receiving a second RF input signal which includes a multitude of second channels. The second downconverter circuit frequency downconverts the second RF input signal to a second IF signal including said multitude of second channels. | 11-26-2009 |
| 20090322578 | APPARATUS AND METHODS FOR DIRECT QUADRATURE SAMPLING - Methods and apparatuses are provided for performing direct quadrature sampling. One method for sampling quadrature baseband components of a bandpass signal includes receiving a bandpass signal, sampling the bandpass signal using a first sampling clock and a second sampling clock, where the first and the second sampling clocks have the same frequency and are offset by a predetermined phase, and aligning the sampled signals temporally to produce in-phase and quadrature samples corresponding to baseband in-phase and quadrature components. An apparatus for directly sampling baseband quadrature components of a bandpass signal is also presented, which includes a first analog-to-digital converter (ADC) configured to receive a bandpass signal, a second ADC configured to receive the bandpass signal, where the second ADC has a clock having a phase offset with respect to clock signal of the first ADC, and an interpolator coupled to the first ADC configured provide coincident samples. | 12-31-2009 |
| 20090327384 | SYSTEM AND METHOD FOR ACTIVE DIPLEXERS - The present invention relates to methods and systems for signal filtering in electronic devices and more particularly, some embodiments related to methods and systems for filtering of radio frequency (RF) signals. In some embodiments, a filter circuit may comprise a down-converter, a filter, coupled to the down-converter and configured to filter the down-converted signal, and an up-converter, coupled to the filter. Various embodiments might also include a combining circuit, coupled to the up-converter and configured to combine the filtered, up-converted signal and the input signal. | 12-31-2009 |
| 20110037628 | METHOD AND SYSTEM FOR ACCELERATED ANALOG TO DIGITAL CONVERSION - Techniques for accelerated processing associated with analog to digital signal conversion are disclosed. Accelerated processing is provided for sample-and-hold and track-and-hold circuits used with analog to digital converters in various embodiments. An abbreviated sampling state, an abbreviated reset state, or both are employed in various embodiments. By accelerating processing so as to avoid the need for waiting for a signal to settle within a predetermined tolerance, errors of different types may be incurred. Such errors are determined during calibration and stored for future retrieval and error compensation. Techniques for online and offline calibration are disclosed, whereby calibration may or may not impact normal signal conversion processing. Techniques disclosed herein find broad applicability in analog to digital conversion and yield faster processing in a variety of contexts. | 02-17-2011 |
| 20110075780 | Method and Apparatus for Bandpass Digital to Analog Converter - Systems and methods for providing a mechanism by which digital signals can be converted to analog signals with an efficient structure that reduces the number of filters required by providing a mechanism for cancelling images that would otherwise be generated. By adjusting three parameters in the system, a selection can be made as to whether to generate upper sidebands, lower sidebands and in which direction the envelope of the output from the system will be skewed. | 03-31-2011 |
| 20110299441 | Method and Apparatus for Real Time Multiplexing with Transmitter and Antenna Array Elements - A method of signal processing, or corresponding apparatus, includes providing digital input signals representing beamforming data to be transmitted on respective antennas. One of the digital input signals is selected at a time among a plurality of times, to cycle through the digital input signals repeatedly and provide a multiplexed digital signal, which is converted to a multiplexed analog signal. The multiplexed analog signal is filtered to pass a predetermined frequency band and demultiplexed to provide analog output signals. One of the analog output signals is selected and provided to a corresponding antenna for transmission. Sharing a transmitter and DAC among multiple antennas results in reduced cost and power. Such cost and power reductions in turn enable larger antenna arrays than are available with prior art techniques, thereby promoting increased throughput and coverage. | 12-08-2011 |
| 20110299630 | Method and Apparatus for Real Time Multiplexing with Receiver and Antenna Array Elements - A method of signal processing, or corresponding apparatus, includes providing multiple analog receive signals at respective antennas and selecting one antenna at a time in an iterative manner, to cycle through the antennas and provide a multiplexed analog signal. The multiplexed analog signal is filtered at a filter to pass a predetermined frequency band. The multiplexed analog signal is sampled at a single analog to digital converter to generate a multiplexed digital signal. The multiplexed digital signal is demultiplexed to generate multiple digital signals for digital processing. Sharing a receiver and ADC among multiple antennas results in reduced cost and power. Such cost and power reductions in turn enable larger antenna arrays than are available with prior art techniques, thereby promoting increased throughput and coverage. | 12-08-2011 |
