Abstract: A catalyst structure includes: (1) a substrate; (2) a catalyst layer on the substrate; and (3) an adhesion layer disposed between the substrate and the catalyst layer. In some implementations, an average thickness of the adhesion layer is about 1 nm or less. In some implementations, a material of the catalyst layer at least partially extends into a region of the adhesion layer. In some implementations, the catalyst layer is characterized by a lattice strain imparted by the adhesion layer.

Abstract: A catalyst structure includes: (1) a substrate; (2) a catalyst layer on the substrate; and (3) an adhesion layer disposed between the substrate and the catalyst layer. In some implementations, an average thickness of the adhesion layer is about 1 nm or less. In some implementations, a material of the catalyst layer at least partially extends into a region of the adhesion layer. In some implementations, the catalyst layer is characterized by a lattice strain imparted by the adhesion layer.

Abstract: The present disclosure provides methods, compositions, kits and systems for nucleic acid amplification. In some embodiments, nucleic acid amplification methods include subjecting the nucleic acid to be amplified to partially denaturing conditions. In some embodiments, nucleic acid amplification methods include amplifying without fully denaturing the nucleic acid that is amplified. In some embodiments, the nucleic acid amplification method employs an enzyme that catalyzes homologous recombination and a polymerase. In some embodiments, methods for nucleic acid amplification can be conducted in a single reaction vessel and/or in a single continuous liquid phase of a reaction mixture, without need for compartmentalization of the reaction mixture or immobilization of reaction components.

Abstract: Systems and methods are disclosed for detecting temporary high level impairments, such as noise or interference, for example, in a communications channel, and subsequently, mitigating the deleterious effects of the dynamic impairments. In one embodiment, the method not only performs dynamic characterization of channel fidelity against impairments, but also uses this dynamic characterization of the channel fidelity to adapt the receiver processing and to affect an improvement in the performance of the receiver. For example, in this embodiment, the method increases the accuracy of the estimation of the transmitted information, or similarly, increases the probability of making the correct estimates of the transmitted information, even in the presence of temporary severe levels of impairment. The channel fidelity history may also be stored and catalogued for use in, for example, future optimization of the transmit waveform.

Abstract: Systems and methods are disclosed for detecting temporary high level impairments, such as noise or interference, for example, in a communications channel, and subsequently, mitigating the deleterious effects of the dynamic impairments. In one embodiment, the method not only performs dynamic characterization of channel fidelity against impairments, but also uses this dynamic characterization of the channel fidelity to adapt the receiver processing and to affect an improvement in the performance of the receiver. For example, in this embodiment, the method increases the accuracy of the estimation of the transmitted information, or similarly, increases the probability of making the correct estimates of the transmitted information, even in the presence of temporary severe levels of impairment. The channel fidelity history may also be stored and catalogued for use in, for example, future optimization of the transmit waveform.

Abstract: Systems and methods are disclosed for detecting temporary high level impairments, such as noise or interference, for example, in a communications channel, and subsequently, mitigating the deleterious effects of the dynamic impairments. In one embodiment, the method not only performs dynamic characterization of channel fidelity against impairments, but also uses this dynamic characterization of the channel fidelity to adapt the receiver processing and to affect an improvement in the performance of the receiver. For example, in this embodiment, the method increases the accuracy of the estimation of the transmitted information, or similarly, increases the probability of making the correct estimates of the transmitted information, even in the presence of temporary severe levels of impairment. The channel fidelity history may also be stored and catalogued for use in, for example, future optimization of the transmit waveform.

Abstract: A method of parameter estimation in a shared channel communications system includes the steps of receiving a preamble including a first sequence corresponding to a sequence having zero autocorrelation, a second sequence having zero autocorrelation, and a third sequence having zero autocorrelation, performing a coarse carrier frequency estimate based on the first sequence, and performing a fine carrier frequency estimate based on the second and third sequences.

Abstract: Systems and methods are disclosed for detecting temporary high level impairments, such as noise or interference, for example, in a communications channel, and subsequently, mitigating the deleterious effects of the dynamic impairments. In one embodiment, the method not only performs dynamic characterization of channel fidelity against impairments, but also uses this dynamic characterization of the channel fidelity to adapt the receiver processing and to affect an improvement in the performance of the receiver. For example, in this embodiment, the method increases the accuracy of the estimation of the transmitted information, or similarly, increases the probability of making the correct estimates of the transmitted information, even in the presence of temporary severe levels of impairment. The channel fidelity history may also be stored and catalogued for use in, for example, future optimization of the transmit waveform.

Abstract: Systems and methods are disclosed for detecting temporary high level impairments, such as noise or interference, for example, in a communications channel, and subsequently, mitigating the deleterious effects of the dynamic impairments. In one embodiment, the method not only performs dynamic characterization of channel fidelity against impairments, but also uses this dynamic characterization of the channel fidelity to adapt the receiver processing and to affect an improvement in the performance of the receiver. For example, in this embodiment, the method increases the accuracy of the estimation of the transmitted information, or similarly, increases the probability of making the correct estimates of the transmitted information, even in the presence of temporary severe levels of impairment. The channel fidelity history may also be stored and catalogued for use in, for example, future optimization of the transmit waveform.

Abstract: Carrier frequency offset (CFO) estimation from preamble symbols. Any communication receiver may be adapted to perform the CFO estimation. The CFO estimation is performed using a low complexity, high accuracy CFO estimation method. The operation may be described as follows: each element of a received sequence is divided by the corresponding preamble element, the resulting sequence is divided into N subgroups, and each subgroup is then averaged. The phase differential of the resulting sequence is computed, averaged, and used to compute an estimate of the carrier frequency offset. This approach to performing CFO estimation is of relatively high estimation accuracy and of relatively low computational complexity.

Abstract: A communication device constructed according to the present invention detects impulse noise in a preamble sequence. In detecting impulse noise in the preamble sequence the communication device first receive a preamble sequence that includes a plurality of preamble symbols. The communication device then divides the plurality of preamble symbols by at least one known preamble symbol to produce a plurality of preamble gains and/or a plurality of preamble phases corresponding to the plurality of preamble symbols. Finally, the communication device determines, based upon the plurality of preamble gains and/or the plurality of preamble phases, that at least one preamble symbol has been adversely affected by a impulse noise. The communication device may discard at least one preamble symbol that has been adversely affected by impulse noise from the plurality of preamble symbols.

Abstract: A filter settings generation operation includes sampling a communication channel to produce a sampled signal. The sampled signal is spectrally characterized across a frequency band of interest to produce a spectral characterization of the sampled signal. This spectral characterization may not include a signal of interest. The spectral characterization is then modified to produce a modified spectral characterization. Filter settings are then generated based upon the modified spectral characterization. Finally, the communication channel is filtered using the filter settings when the signal of interest is present on the communication channel. In modifying the spectral characterization, pluralities of spectral characteristics of the spectral characterization are independently modified to produce the modified spectral characterization. Modifications to the spectral characterization may be performed in the frequency domain and/or the time domain.

Abstract: A number of features for enhancing the performance of a communication system, in which data is transmitted between a base station and a plurality of subscriber stations located different distances from the base station, are presented. The power transmission level, slot timing, and equalization of the subscriber stations are set by a ranging process. Data is transmitted by the subscriber stations in fragmented form. Various measures are taken to make transmission from the subscriber stations robust. The uplink data transmission is controlled to permit multiple access from the subscriber stations.

Abstract: A number of features for enhancing the performance of a wireless communication system, in which data is transmitted between a central node and a plurality of subscriber nodes located remotely with respect to the central node, are presented. The power transmission level, slot timing, and equalization of the subscriber nodes are set by a ranging process. Data is transmitted by the subscriber nodes in fragmented form. Various measures are taken to make transmission from the subscriber nodes robust. The uplink data transmission is controlled to permit multiple access from the subscriber nodes.

Abstract: A receiver includes a filter stage that receives, filters, and equalizes a received signal, and a decisional feedback loop coupled to the filter stage that receives and processes a signal output from the filter stage using remodulation. The decisional feedback loop includes a converter that generates a baseband signal, a detector that generates a decision signal, a restorative signal generator that generates a restorative signal using remodulation, and a carrier loop that generates a frequency correction signal and provides a frequency-offset estimate. The restorative signal and the frequency correction signal are provided to the converter to compensate for inter-symbol interference. The presented “remodulation” technique decouples interaction between the carrier loop, the pre-filters, and the equalizer of the restorative signal generator, providing an architecture that is more stable and significantly faster than conventional architectures.

Abstract: A system and method are used to provide uncorrelated code hopping in a communications system. A multi-bit linear shift register receives data and clocks the data fifteen times. A word assembler receives the shifted data and outputs a fifteen bit word. A mixer mixes the fifteen bit word with an numerical value of active codes to generate a mixed signal. A divider divides the mixed signal to produce a divided signal. A truncator truncates the divided signal to its seven most significant bits to produce a pseudo random hop number. A code matrix shifter circularly shifts the active codes in a code matrix based on the pseudo random hop number to produce a circularly shifted code. A transmitter transmits the circularly shifted code matrix.

Abstract: Iterative data-aided carrier CFO estimation for CDMA systems. Any communication receiver may be adapted to perform the iterative data-aided carrier CFO estimation. The iterative data-aided carrier CFO estimation is performed using a high accuracy method. The operation may be described as follows: a received signal is despread and buffered. Using the received preamble sequence, an initial estimate of the CFO is obtained. This estimate is used to correct the whole despread data. The corrected data using the initial CFO estimate is sliced. Each despread data symbol is divided by the corresponding sliced data decision. The obtained sequence is then averaged across different codes to obtain a less noisy sequence, which is then used to estimate the CFO again. The procedure can be repeated (iterated) to obtain a more accurate carrier frequency offset estimate; the number of times in which the procedure is repeated may be programmable or predetermined.

Abstract: A number of features for enhancing the performance of a communication system, in which data is transmitted between a base station and a plurality of subscriber stations located different distances from the base station, are presented. The power transmission level, slot timing, and equalization of the subscriber stations are set by a ranging process. Data is transmitted by the subscriber stations in fragmented form. Various measures are taken to make transmission from the subscriber stations robust. The uplink data transmission is controlled to permit multiple access from the subscriber stations.

Abstract: A system for detecting collisions in a shared communications medium, such as a TDMA medium, includes a receive path adapted to generate a first intermediate signal, a second intermediate signal, and a data symbol sequence from an input signal. A preamble detection module generates a correlation metric from the first intermediate signal. A power measurement module generates a power indication signal from the second intermediate signal. A noise measurement module generates a noise indication signal from the second intermediate signal and the data symbol sequence. A processing module is adapted to characterize the input signal as a collision for certain values of correlation metric, power indication signal, and noise indication signal.

Abstract: A number of features for enhancing the performance of a cable transmission system, in which data is transmitted between a cable modem termination system at a headend and a plurality of cable modems located different distances from the headend, are presented. The power transmission level, slot timing, and equalization of the cable modems are set by a ranging process. Data is transmitted by the modems in fragmented form. Various measures are taken to make transmission from the cable modems robust. The upstream data transmission is controlled to permit multiple access from the cable modems.