Abstract: An adaptive frequency equalization system providing an equalizer that has programmable taps that adjusts magnitude and phase of symbol information of a received signal and that provides equalized symbol information. The system includes a hard decision circuit that selects ideal symbol values using the equalized symbol information. A frequency response circuit determines frequency response update values using the ideal symbol values and the received signal. An adjust circuit updates stored frequency response information using the frequency response update values, and also updates the programmable taps of the equalizer using the stored frequency response information.

Abstract: Crosstalk interference induced by the adjacent pairs is one of the major performance limiting factors of DSL systems. As there is a rapid increase in the deployment of DSL services worldwide, the need to provide information about noise related parameters to the operators and the service providers is of utmost importance. Satisfying such a need enables operators to anticipate the line capacity and understand the noise level characteristics of the loop environment. Specifically, crosstalk and more particularly upstream near end crosstalk (NEXT) in the presence of narrowband interference can be classified to isolate the particular service type causing the upstream NEXT. The identification of the service type of the upstream NEXT would enable operators to address the disturber.

Abstract: An inkjet firing architecture for use in association with a device utilizing an ink jet head. The inkjet firing architecture includes a fire synchronization block including an N-entry delay line, at least one vector sequencing block, and a vector compositing block. The N-entry delay line is operable to simultaneously delay multiple incoming external events for varying periods of time prior to passing each of the events to one of M event sub-dividing stages and provide a fire synchronization block output that is related at least in part to the delayed incoming external events. Each of the M event sub-dividing stages emits a programmable series of sub-events, each of the sub-events being separated in time by a sub-event interval. Each programmable series of sub-events ends with an independent Mth level sub-event that is passed along as the fire synchronization block output to the at least one vector sequencing block.

Abstract: A receiver circuit processes a received signal to determine information regarding a guard interval therein. The receiver circuit typically forms digital samples from the received signal; generates a correlation function with peaks at positions that are determined by the size of the guard interval and a position of the guard interval within the received signal. The receiver circuit includes one or more comb filters, each corresponding to a possible guard interval size, each receiving a series of locations at which the correlation function exceeds a predetermined threshold, and each producing an output that provides information about the guard interval size and/or position. This advantageously allows the receiver circuit to determine the guard interval size quickly, for example, even in the case of received signals with relatively low signal-noise ratio.

Abstract: A multi-rate encoder and decoder system is disclosed. The multi-rate encoder and decoder system is capable of operating with a mother code or a subset code of the mother code and includes a trellis encoder having a set of inputs and a set of outputs corresponding to the mother code and a select unit capable of removing the set of inputs into the trellis encoder that correspond to the mother code but not the subset code prior to encoding. The multi-rate encoder and decoder system further includes a decoder having a set of decoder inputs and a set of decoder outputs corresponding to the mother code and a decoder select unit capable of ignoring transitions in the trellis code produced by the encoder that belong to the mother code but not to the subset code.

Abstract: A mixer for use in a transceiver comprises an LO switching pair and a folded transconductor. The mixer can be used as an upconversion or down conversion mixer and provides increased headroom and linearity, while still reducing current consumption. The mixer can be configured for differential inputs and outputs and the folded transconductor can comprises a MOSFET differential pair.

Abstract: An integrated tuner is programmable to optimize its components for either analog signal reception or digital signal reception. Power to the components is increased for analog operation and decreased for digital operation. The tuner also includes a selectable and integrated low noise amplifier that may be selected for single-signal reception and bypassed for multi-signal reception.

Abstract: The present invention provides a method and apparatus for a new interleaver adaptation scheme that achieves “error free” and zero delay (interleaving—triangular) or near zero delay variation (interleaving—GCI), and with easier implementation but no additional memory required. The dummy insertion methods and systems embodiments of the invention provide an effective dummy byte insertion scheme for applications that require seamless on-line rate changes, e.g., SRA (seamless rate adaptation), DRR (dynamic rate repartitioning) and adaptive INP (impulse noise protection).

Abstract: A DC offset correction system for a direct-conversion receiver is disclosed that may include a DC feedback correction servo-loop in signal communication with a baseband section, where the DC feedback correction servo-loop is coupled to both the input and output of the baseband section and an attenuator within the DC feedback correction servo-loop.

Abstract: An economic low-complexity system and method for echo cancellation are disclosed. The system and method are particularly suited for multi-carrier VDSL using the U0 band. The techniques taught herein may be implemented in VDSL and VDSL2 systems and used to receive signals in three bands (e.g., U0, U1 and U2) simultaneously.

Abstract: An improved combined Switching Data Unit (SDU) queuing discipline for unicast and multicast (Protocol Data Unit) PDU forwarding at a switching node is provided. Multicast SDU descriptors are replicated and stored in entries of a First-In/First-Out queue portion of a hybrid output port queue. Unicast SDU descriptors are chained in entries of a linked list queue portion of the hybrid output port queue. Servicing of the hybrid queue uses hybrid queue counters, and inter-departure-counters stored in multicast FIFO queue entries to keep track of the number of unicast SDU linked list entries, to be serviced between the multicast FIFO queue entries. The combined hybrid queue derives storage efficiency benefits from linking unicast PDUs in linked lists and further derives benefits from a simple access to multicast PDU entries.

Abstract: A system and method for wireless waking computing devices over a computer network is provided. A signal is broadcast over the network that includes one or more device specific wake-up data sequences. Each device specific wake-up data sequence includes multiple iterations of the hardware address of the wireless network card associated with that device. While in a reduced power or “sleep mode”, the wireless network card monitors wireless channels for packets containing a wake-up data sequence. If a wake-up data sequence is received, the sequence is matched against the hardware address information for that network card. If a match is determined, the network card sends a signal to the computing device causing full system power to be restored. A signal is sent to the network confirming that the device has been successfully woken from the sleep mode.

Abstract: Disclosed are exemplary techniques for compressing ATM cells by substituting reduced headers for the original headers. A header table may be maintained at the transmitting end whereby headers are stored in table entries based on a table index generated from a hash function applied to the headers. A copy of the header table may be maintained at the receiving end and may be updated by populating idle cells with header table contents. Upon receipt of a reduced ATM cell at the receiving end, the reduced header may be replaced with a full header obtained from the copy of the header table maintained at the receiving end. The present invention further provides techniques for registration and management of hash collisions.

Abstract: The modulation method and system of the presented herein involves mapping data onto a constellations comprising a set of concentric circles in a two-dimensional plane, one dimension for the amplitude and one for the phase. The phase dimension is coded differentially, while the amplitude dimension is coded coherently. The circles in each constellation may contain equal number of points, and in other embodiments more points may be used on the outer circles. The data may be coded with dual Trellis codes, one code for the phase data and another code for the amplitude data.

Abstract: Disclosed is an apparatus and method for storing and searching computer node addresses in a computer network system. In one embodiment, the apparatus comprises a frame forwarding device such as a switch. The switch includes two MAC address tables including a primary MAC address table and secondary MAC address table both for storing and searching MAC addresses. The primary table stores records that contain compressed values of MAC addresses. The records are contained in storage locations that are referenced using the compressed value of the MAC address as a search index. In order to account for searching collisions that may result from different MAC addresses compressing to the same value, each record in the primary address table is linked to a chain of records in the secondary table. The records in the secondary table store the full value of the MAC address. Each chain of records in the secondary address table contains MAC addresses the present invention.

Abstract: A system for and method of mapping successive bits of digital data into BPSK symbols using one or more BPSK symbol constellations such that orthogonal BPSK constellations are applied to successive bits of the digital data. The system and method may toggle between applying first and second orthogonal constellations as successive bits of the digital data are encountered. Alternatively, the system and method may successively rotate by 90° the constellation to be applied as successive bits of the digital data are encountered.

Abstract: A receiver circuit is for processing a received signal which includes at least a first portion and a second portion which repeats the content of the first portion after a repeat interval. For example, the receiver may be for DVB-T signals using COFDM. In order to ensure that the estimated symbol start position is accurate, the receiver calculates two correlation values, namely an early correlation and a late correlation. The early correlation is measured between samples ahead of an assumed first portion start position and ahead of an assumed second portion start position, and the late correlation is measured between samples behind an assumed first portion end position and behind an assumed second portion end position. When the assumed start and end positions are accurate, the early and late correlations are equal, and so the assumed start and end positions are controlled to equalize the early correlation and the late correlation.

Abstract: An exemplary satellite communication system comprises a service provider unit communicably coupled to a number of subscriber units via satellite transmission. The service provider unit includes an encoder configured to encode source data into a serial transmit sequence, and is further capable of supporting at least two modes of operation. The serial transmit sequence includes a first unique word identifying a first mode of operation, and is followed by a first payload packet having a first number of channel symbols corresponding to a source packet encoded in accordance with the first mode of operation identified by the first unique word. The first payload packet is encapsulated by two unique words and the time interval between the two unique words is used to determine the first mode of operation identified by the first unique word.

Abstract: The present application provides a variety of exemplary embodiments, such as modem systems, modem devices, modem connectors, host connectors, communication systems and communication cards. For example, there is provided a modem device for use to enable a host to communicate over a communication line, wherein the host has a host connector. The modem device comprises a line side circuitry capable of interfacing with the communication line; and a digital isolation barrier (DIB) coupled to the line side circuitry, the digital isolation barrier capable of being connected to a modem connector for connection to the host connector, wherein the digital isolation barrier is capable of isolating the modem connector from the line side circuitry. Moreover, the line side circuitry may include a line side DIB interface for communication with the digital isolation barrier. Also, the modem connector may be connected to the digital isolation barrier via one or more lines.

Abstract: A method and apparatus are disclosed for enabling coexistence in a wireless local-area network between legacy stations and stations that can transmit higher-bandwidth signals. The illustrative embodiment employs a transceiver that can transmit and receive higher-bandwidth signals over a combination of two or more shared-communications channels, and an enhanced medium access control (MAC) protocol by which stations progressively reserve channels before transmitting higher-bandwidth signals.