| Patent application number | Description | Published |
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| 20080291989 | Crosstalk Estimation Methods and Apparatus Using Auxiliary Time-Domain Signals - Techniques are disclosed for measuring crosstalk between at least two communication channels of a communication system. A receiver of the system receives a signal over a given one of the communication channels from a transmitter of the system. The receiver correlates the received signal with a sequence of time-domain signals associated with another of the communication channels, and generates a measure of crosstalk between the given communication channel and the other communication channel based on the correlation between the received signal and the sequence of time-domain signals. The sequence of time-domain signals may be selected from a designated set of M-sequences. | 11-27-2008 |
| 20090034668 | METHOD AND APPARATUS FOR SYNCHRONIZING A RECEIVER - Various embodiments generally relate to a method for synchronizing a receiver, said method including receiving a stream that includes a cyclic extension, estimating a size of the cyclic extension, extracting an amount of the stream according to the estimated size, and comparing the extracted amount to the stream to determine thereby a portion of the stream likely to include a symbol start point. | 02-05-2009 |
| 20090044079 | RATE-ADAPTIVE FORWARD ERROR CORRECTION FOR OPTICAL TRANSPORT SYSTEMS - An optical transport system (OTS) having a plurality of optical transponders (OTs) connected via one or more optical links and adapted to communicate with one another using respective rate-adaptive forward-error-correction (FEC) codes. In one embodiment, the OTS has a rate control unit (RCU) adapted to configure the OTs to dynamically adjust the rates of the FEC codes based on an estimated performance margin for each link between two respective communicating OTs to optimize the overall capacity of the OTS while maintaining an adequate, but not excessive, overall system margin. | 02-12-2009 |
| 20090059780 | METHOD AND APPARATUS FOR SELF-TUNING PRECODER - Techniques are disclosed for compensating for crosstalk using adaptation of data signals transmitted over respective channels of a communication system. For example, a method includes the following steps. A first set of estimated measures of crosstalk is obtained for at least a selected portion of a plurality of communication channels over which data signals are to be transmitted from a transmitter to at least a selected portion of a plurality of receivers. A first set of data signals based on the first set of estimated measures of crosstalk is adapted to generate a first set of adjusted data signals. The first set of adjusted data signals is transmitted to corresponding ones of the plurality of receivers. A second set of estimated measures of crosstalk is obtained for the selected portion of the plurality of communication channels. A second set of data signals for transmission based on the second set of estimated measures of crosstalk is adapted to generate a second set of adjusted data signals. Iteration of the obtaining, adjusting and transmitting steps is performed so as to reduce an error between subsequent estimated measures of crosstalk and actual measures of crosstalk for the plurality of communication channels. | 03-05-2009 |
| 20090060013 | OPTIMIZING PRECODER SETTINGS USING AVERAGE SINR REPORTS FOR GROUPS OF TONES - Techniques are disclosed for compensating for crosstalk using adaptation of data signals transmitted over respective channels of a communication network. In one example, a method comprises the following steps. Data is transmitted to a communication network device via a communication line during a sequence of periods. For each period of the sequence of periods, a separate value of a measure of crosstalk that was measured at the communication network device is received, each value being an average of measurements at the device of measures of crosstalk for a plurality of communication network signal subcarriers. For each individual signal subcarrier of the plurality, a matrix is updated based on the received values, the matrix being configured to precode data transmissions to the communication network device over the individual signal subcarrier. The communication network may be a DSL system, the signal subcarriers may be DSL tones, and the measure of crosstalk may be a SINR value. | 03-05-2009 |
| 20090116582 | INTERPOLATION METHOD AND APPARATUS FOR INCREASING EFFICIENCY OF CROSSTALK ESTIMATION - Techniques are disclosed that efficiently obtain channel crosstalk estimates in DSL systems and other communication systems that may include unsynchronized channels. For example, a method includes obtaining a first set of estimated measures of crosstalk for a first portion of a plurality of communication channels over which data signals are to be transmitted from a transmitter to a plurality of receivers, and interpolating a second set of estimated measures of crosstalk for a second portion of the plurality of communication channels based on the first set of estimated measures of crosstalk. The first portion of the plurality of communication channels may be a subset of the plurality of communication channels and the second portion of the plurality of communication channels is a remainder of the plurality of communication channels. Each estimated measure of crosstalk may relate to at least one tone associated with at least one of the plurality of communication channels. | 05-07-2009 |
| 20090245081 | Fast Seamless Joining of Channels in a Multi-Channel Communication System - At least one channel is joined to a group of active channels in a communication system by transmitting control signals to configure respective customer premises equipment (CPE) of the active channels into a joining mode of operation, and transmitting a joining signature sequence to CPE of the joining channel over a downstream data signal path of the joining channel. A central office (CO) or other access node of the system receives correlation results from respective active channel CPE, estimates crosstalk from the joining channel into the active channels based on the correlation results, configures a precoder based on the estimated crosstalk, and adds the joining channel to the group of active channels. The channels may comprise respective subscriber lines of a DSL communication system. | 10-01-2009 |
| 20090296865 | METHODS AND APPARATUS FOR PROVIDING SYNCHRONIZATION IN A MULTI-CHANNEL COMMUNICATION SYSTEM - A multi-channel processing module is arranged in series with multiple channels of a communication system. The processing module synchronizes downstream symbols among the channels, and synchronizes downstream symbols for at least a given one of the channels with upstream symbols for that channel. The synchronization of downstream symbols among the channels and the synchronization of downstream symbols for at least the given channel with upstream symbols for that channel are collectively achieved by adjusting downstream and upstream adjustable delay elements associated with respective downlink and uplink signal paths in the multi-channel processing module. The channels may comprise respective subscriber lines of a DSL communication system. | 12-03-2009 |
| 20090304056 | Signal suspension and resumption in DSL systems - A method includes maintaining temporally parallel DSL data communication sessions with DSL modems of a group via a set of lines. The method includes, in response to substantially stopping to receive DSL communications from one of the DSL modems via one of the lines, transmitting a substantially reduced average power to the one of the lines and monitoring the one of the lines to determine whether DSL communications have restarted being received from the one of the DSL modems. The method also includes resuming the maintaining of the temporally parallel DSL communication sessions in response to the monitoring determining that DSL communications have restarted being received from the one of the DSL modems. | 12-10-2009 |
| 20090310502 | Device and associated method for crosstalk estimation - The present invention relates to a crosstalk estimation device for estimating crosstalk between communication lines in a precoding group. The crosstalk estimation device comprises transmission means for transmitting a pilot sequence and reception means for receiving error feedback on one or more communication lines in the precoding group. The crosstalk estimation device further comprises crosstalk estimation means for combining the pilot sequence with the error feedback in order to obtain a crosstalk estimation between the communication lines. The device further comprises selection means for selecting a subset of one or more communication lines from the precoding group. The transmission means are adapted to transmit the pilot sequence only on the subset. | 12-17-2009 |
| 20100046684 | Communication system for transmitting sync-flags and pilot symbols and method thereof - The present invention relates to a communication system and method for transmitting sync flags and pilot symbols during sync symbol periods. Example embodiments provide a method for sharing sync symbols to communicate flag sequences and pilot sequences during a sequence of sync symbol periods. The method includes modulating the pilot sequence by multiplying a pilot code by each value of the pilot sequence, and modulating the flag sequence by multiplying a flag code by each value of the flag sequence. The pilot and flag codes are mutually orthogonal to each other and each includes at least two non-zero values. The method further includes generating a resulting sync symbol sequence based on the modulated pilot sequence and modulated flag sequence, and sending the resulting sync symbol sequence during the sync symbol period. | 02-25-2010 |
| 20100153828 | Method and apparatus for error detection in a communication system - A method processes a data packet in a first sequence of disjoint original segments of the same length. The method includes modifying a first of the original segments of the first sequence by modifying one or more symbols therein. A start of the data packet is located in the first of the original segments and is positioned after a first digital data symbol therein. The method also includes modifying a last of the original segments of the first sequence by modifying one or more digital data symbols therein. An end of the data packet is located in the last of the original segments and is located before the last digital data symbol therein. The method also includes determining a remainder sequence by effectively performing a polynomial division on a second sequence of disjoint segments that are derived from the first sequence. Each segment of the second sequence corresponds to and is derived from one of the original segments of the first sequence. The segments of the second sequence have the length of the original segments of the first sequence. A first of the derived segments of the second sequence is the modified first of the original segments. A last of the derived segments of the second sequence is derived from the modified last of the original segments. | 06-17-2010 |
| 20100245534 | Method and apparatus for the efficient transmission of multimedia streams for teleconferencing - A teleconferencing system in which a teleconference controller advantageously uses information relating to the network topology layout of remote nodes which are to participate in a teleconference, and then advantageously directs the transmission of video and/or audio streams from a source node to an identified subset of the remote nodes based on the capabilities of the nodes and the network links. These nodes which initially receive the video and/or audio streams then advantageously forward the streams in turn to other nodes in their vicinity using peer-to-peer network connectivity techniques. The identification of the subset of nodes which serve as peer-to-peer forwarding nodes may be based on node activity, node service capacity, the impact on network links between the node and the requester, the distance and/or latency between the node and the requester, and the ability of the node to meet requests including video transcoding requests. | 09-30-2010 |
| 20100278222 | Validated signal resumption in DSL systems - An apparatus includes a DSL transceiver configured to transit to a DSL wait state in which a power transmitted from the DSL transceiver to a local-end line is substantially reduced in response to an interruption or substantial stop at the DSL transceiver of reception of DSL communications from the local-end line. The DSL transceiver is configured to transmit to the local-end line a DSL acknowledge signal in response to receiving from the local-end line a DSL wait signal. The DSL transceiver is configured to resume to transmit DSL communications to the local-end line at a power substantially higher than the power transmitted thereto in the DSL wait state in response either to receiving from the local-end line DSL transmissions at a substantially higher power than received there from in the DSL wait state or to receiving from the local-end line a second DSL acknowledge signal. | 11-04-2010 |
| 20100315479 | System to freely configure video conferencing camera placement - Embodiments of the present invention are directed to cordless video conferencing camera adaptors and video conferencing systems including the camera adaptors. Embodiments of the present invention overcome some of the inherent problems of known video conferencing products by being a part of a portable and configurable video conferencing system, which can be used in various meeting rooms, laboratories, training rooms, and conference halls. For example, embodiments of the invention allow use of low cost (e.g., under $100) cameras to provide any angle of video coverage in any conference room setting. | 12-16-2010 |
| 20100315481 | Portable video conferencing system with universal focal point - Embodiments of the present invention are directed to compact portable video conferencing systems, which eliminate the need for other meeting room appliances for a video conference. The systems provide the freedom to hold video conferences with a few participants in any setting, e.g., a manager's office, a conference room, multiple locations, etc. Embodiments provide portable video conferencing systems, which allow all the meeting participants, including local and remote users, to maintain constant eye contact throughout the meeting. An embodiment of the invention provides a portable video conferencing system including a base, a dual-sided display and a camera unit. | 12-16-2010 |
| 20100316380 | SYSTEM AND METHOD FOR CHANNEL-ADAPTIVE ERROR-RESILIENT TRANSMISSION TO MULTIPLE TRANSCEIVERS - In a passive optical network, a downstream transmission rate from an OLT to multiple ONTs can be optimized by matching a transmission scheme for frames addressed to a channel to the downstream transmission characteristics of the channel. An FEC coding can be made channel dependent so that channels with low error rates can use minimal protection, and therefore minimal overhead, while channels with high input bit error rates can use the level of FEC coding required to produce a desired output bit error rate. | 12-16-2010 |
| 20100316381 | SYSTEM AND METHOD FOR CHANNEL-ADAPTIVE ERROR-RESILIENT BURST MODE TRANSMISSION - In a passive optical network, an upstream transmission rate from an ONT to an OLT can be optimized by matching a transmission scheme for a channel to the upstream transmission characteristics of the channel. An FEC coding can be made channel dependent so that channels with low error rates can use minimal protection, and therefore minimal overhead, while channels with high input bit error rates can use the level of FEC coding required to produce a desired output bit error rate. | 12-16-2010 |
| 20100329386 | Crosstalk Control Method and Apparatus Using a Bandwidth-Adaptive Precoder Interface - In a communication system, a precoder is coupled between first and second portions of each of a plurality of transmitters. The precoder is configured to receive an adaptive index representation of a scaled signal associated with the first portion of a first one of the transmitters, and to process the adaptive index representation using an adjusted precoder coefficient to generate a precompensation signal. The precompensation signal is supplied from the precoder to the second portion of a second one of the transmitters for use in precompensation of at least one signal to be transmitted by the second transmitter. | 12-30-2010 |
| 20100329399 | Method and Apparatus for Interference Post-Compensation Using a Bandwidth-Adaptive Postcoder Interface - In a communication system, a postcoder is coupled between first and second portions of each of a plurality of receivers. The postcoder is configured to receive an adaptive index representation of a scaled signal associated with the first portion of a first one of the receivers, and to process the adaptive index representation using an adjusted postcoder coefficient to generate a postcompensation signal. The postcompensation signal is supplied by the postcoder to the second portion of a second one of the receivers for use in postcompensation of at least one signal received by the second receiver. | 12-30-2010 |
| 20110075834 | CROSSTALK CONTROL USING DELAYED POST-COMPENSATION IN A MULTI-CHANNEL COMMUNICATION SYSTEM - An access node of a communication system receives signals over respective first and second channels of the system, processes the signal received over the second channel and an initialization signal associated with the first channel to obtain estimated crosstalk coefficients characterizing crosstalk from the first channel into the second channel, introduces respective predetermined delays into the respective signals received over the first and second channels, and utilizes the estimated crosstalk coefficients to adjust the signal received over the second channel as delayed by the corresponding predetermined delay in order to compensate for the crosstalk from the first channel into the second channel. The first and second channels may comprise respective joining and active subscriber lines of a DSL system. | 03-31-2011 |
| 20110122854 | Dual transmission for communication networks - A dual transmission network may use a hybrid architecture where two types of links, such as wireless and fixed, function in a parallel manner for communicating control information and data. In at least one example embodiment, an apparatus includes at least two local transceivers and a controller. The controller is connected to control the two local transceivers and configured to establish parallel first and second communication links with a remote terminal via at least one of the local transceivers. The first communication link uses a first physical layer communication protocol and the second communication link uses a second physical layer communication protocol. The second physical layer communication protocol may be different from the first physical layer communication protocol or the first and second transceivers may be configured to operate on different frequencies. | 05-26-2011 |
