Dallas, TX, United States
Dallas, TX, United States

Time filter

Source Type

Patent
Xtendwave XW, LLC | Date: 2013-02-11

A novel and useful multi-antenna receiver that receives, demodulates and decodes a broadcast signal, whose modulation and encoding of time and timing information allow for reliable and power-efficient operation. The multi-antenna receiver of the present invention is adapted to eliminate or substantially reduce the reception nulls that occur in receivers having a single antenna that is placed in a fixed position. Two or more antennas are employed whereby the receiver generates a combined signal based on a combination of the individual antenna signals or selects one of the antenna signals for input to the receiver based on desired criteria such as signal-to-noise-and-interference-ratio (SNIR). This results in greater robustness of the communication link by reducing or eliminating reception nulls and by rejecting interference through the selection of the antenna for which the signal-to-interference ratio is higher. The invention includes various antenna configurations that are adapted to reuse a single core for multiple antennas or to otherwise reduce size and/or cost.


A novel and useful system and method for leap second and daylight saving time (DST) correction for use in a radio controlled clock (RCC) receiver. The RCC receiver extracts schedule information from the frame, including the time for the DST transition and whether a leap second needs to be added at the end of this half-year. Linear error correcting coding is used for the leap second and the DST on/off indications, while non-linear error correcting coding (e.g., a look up table) is used for the DST schedule to enhance reception reliability in the presence of noise and interference. The one second/one hour corrections are scheduled to occur when they should take place and the correction is applied exactly when DST or leap second is to go into effect, without having to receive anything around the time of the correction.


A novel and useful system and method for leap second and daylight saving time (DST) correction for use in a radio controlled clock (RCC) receiver. The RCC receiver extracts schedule information from the frame, including the time for the DST transition and whether a leap second needs to be added at the end of this half-year. Linear error correcting coding is used for the leap second and the DST on/off indications, while non-linear error correcting coding (e.g., a look up table) is used for the DST schedule to enhance reception reliability in the presence of noise and interference. The one second/one hour corrections are scheduled to occur when they should take place and the correction is applied exactly when DST or leap second is to go into effect, without having to receive anything around the time of the correction.


A system and method for a radio controlled clock receiver adapted to extract timing and time information from a phase modulated signal. The official time signal is broadcast from a central location using a modified modulation scheme, which adds phase modulation over the legacy amplitude modulation, such as the legacy WWVB pulse width modulated (PWM)/amplitude shift keying (ASK) modulation, thereby allowing for improved performance. The information modulated onto the phase contains a known synchronization sequence having good autocorrelation properties, error-correcting coding for the time information and notifications of daylight-saving-time (DST) transitions that are provided months in advance. The modulation scheme is based on a form of phase modulation, such as binary-phase-shift-keying (BPSK) or phase reversal keying (PRK). The reception of multiple frames with repeated or sequential information allows for the accumulation of received energy over multiple frames to provide for a corresponding gain in the receiver.


A system and method for a radio controlled clock receiver adapted to extract timing and time information from a phase modulated signal. The official time signal is broadcast from a central location using the modified modulation scheme of the present invention, which adds phase modulation that allows for greatly improved performance. The information modulated onto the phase contains a known synchronization sequence having good autocorrelation properties, error-correcting coding for the time information and notifications of daylight-saving-time (DST) transitions that are provided months in advance. The modulation scheme is based on a form of phase modulation, such as binary-phase-shift-keying (BPSK) or phase reversal keying (PRK). A superframe comprising multiple frames with repeated information allows for the accumulation of received energy over multiple frames to provide for a corresponding gain in the receiver.


A novel and useful system and method for extracting timing, time and additional information from a broadcast received in a radio controlled clock (RCC) receiver. The RCC receiver extracts timing information represented by a known synchronization sequence that is used for acquisition and tracking purposes. The RCC receiver extracts time information as a merged 26-bit time information word linearly coded into 31 bits comprising the number of minutes (or hours) since the turn of the current century. A minute counter representing the 26 bits is converted into the date, hour, and minute. The RCC extracts additional information including the schedule for the next daylight saving time transition and for an imminent leap second. The communications protocol optionally employs error correcting codes to provide protection for data fields in the frame, which the RCC may use to enhance reception reliability in the presence of noise and interference.


Grant
Agency: National Science Foundation | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 500.00K | Year: 2012

This Small Business Innovation Research Phase 2 project targets the realization of a cost-effective solution for achieving increased data throughputs in the crosstalk-constrained copper-medium-based cellular and access backhaul networks, to address the growing demand for capacity experienced in them. Existing equipment, confined to the use of twisted-pairs due to the unavailability of fiber in most locations, often avoids the use of spectrally efficient VDSL, whose high-capacity comes at a cost of vulnerability to interference. The technology developed in Phase 1 of this project, and its implementation in hardware and software as part of the Phase 2 project, will effectively address this vulnerability of VDSL and recover most of its potential capacity through crosstalk cancellation. The company?s key innovation is in non-iterative, low-latency, reduced-complexity, dynamic interference cancellation algorithms, which greatly enhance performance while requiring less than 10% of silicon-area increase in existing VDSL2 multi-channel solutions. The project will involve both research and development aspects, as well as system implementation challenges associated with the minimization of complexity and power consumption. Based on the Phase 1 project?s successful validation of the technology?s critically needed throughput enhancements and its commercial potential, it is anticipated that this technology will be widely incorporated in copper-based equipment. The broader impact/commercial potential of this project is in extending the useful life of the existing in-ground copper infrastructure, thus allowing equipment providers to continue to focus their resources on delivering ever-increasing bandwidths, while also offsetting the high expense of new fiber deployment. Benefits are also realized through the company?s partnerships with universities, where the company works closely with key faculty and with students, provides seminars, and has an ongoing internship program that results in the full-time hiring of graduates. According to publicly available reports, mobile data traffic in North America is expected to increase by a factor of over 20 by the year 2015. This massive increase in data consumption, brought on primarily by the rapid adoption of smart-phones and bandwidth-intensive applications, is already placing an enormous burden on the backhaul infrastructure, which carries telecommunications for cellular, internet and landline voice traffic. Resolution of the bandwidth congestion requires significant improvement in telecom infrastructure including backhaul and access, both of which are largely copper-based in North America. The company?s interference-mitigation technology will address this problem in a cost-effective manner by allowing the growing demand for bandwidth to be satisfied with the existing infrastructure.


Cost-effective structures and methods that allow an integrated digital-to-analog converter (DAC) to simultaneously achieve wide dynamic ranges and bandwidths through the use of built-in measurement and compensation mechanisms that are primarily digital. The measurements of the DACs distortions are made with a relatively simple analog-to-digital converter (ADC) that is not designed to accommodate the combination of the bandwidth and the resolution offered by the DAC, but is nonetheless sufficient in determining the characteristics of the DACs impairments during a calibration procedure. This information is then used in a feed-forward compensation system during the DACs normal operation to estimate and cancel the distortions in its output signal that could result from the various impairments.


Patent
Xtendwave XW, LLC | Date: 2013-02-06

A system and method for processing an input matrix and a MIMO receiver employing the system or the method. In one embodiment, the system includes: (1) a transformer configured to receive a frame of complex data representing only some elements of an input matrix and perform a fast plane rotation on the complex data to yield rotated data and (2) a matrix updater coupled to the transformer and configured to update a memory configured to contain an output matrix with the rotated data. In one embodiment, the system and method are to estimate and mitigate alien cross-talk experienced in a vectored DSL communication system.


Various embodiments of a method of mitigating interference in an OFDMA cellular network and a user terminal incorporating various of the embodiments. In one embodiment, the method includes: (1) selecting at least one dominant interfering signal, (2) generating estimates of a desired signal and the at least one dominant interfering signal, (3) jointly deciding based on the estimates such that an energy of a residual error is reduced and (4) mitigating interference based on the estimates.

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