Abstract: The distance between a first Multi Band Orthogonal Frequency Division Multiplex (MB-OFDM) data transceiver and a second or more such transceiver is determined using known techniques. The radio frequency path loss between transceivers is estimated given said distance, using a known relationship between distance and path loss, and further accounting for line-of-sight or non-line-of-sight conditions if desired. This path loss value is added to the typically minimum transmit power level, absent path loss, needed for reliable data communication. This modified initial transmit power level is then used by the first transceiver to begin the known iterative feedback process of transmit power control (TPC). Because this modified initial transmit power level, based on distance, is closer to the final optimum level, convergence in the TPC process occurs in fewer steps and less time than had the initial transmit power been maximum power as is typical in known TPC systems.

Abstract: The present invention provides a system for obviating interference effects in packet detection within a wireless communications network. A plurality of reference signals is provided—a first of which corresponds to desired packets, and the remainder of which correspond to undesired packets or interference. A plurality of cross-correlation constructs corresponds, respectively, to the plurality of reference signals. Each cross-correlation construct correlates an incoming signal to a plurality of repetitions of its respective reference signal. An analysis construct compares output from each cross-correlation construct with other cross-correlation construct outputs, and with a threshold value, to determine which incoming signal corresponds to desired packet data. Once this incoming signal is identified, packets from the signal may be reliably received.

Abstract: The transmit window size of a Simple Packet Relay Transport protocol packet transmission system can determine the efficiency of transmission and the memory requirements of the transmitter. A sufficiently large transmit window must be maintained to avoid transmission waits which can reduce the utilization of available transmission path bandwidth. However, an oversize window will require excess buffer capacity and therefore utilize additional storage space on the transmitter. A balance in window size is dynamically achieved through monitoring of the buffer write operations to determine the accessibility of the transmit buffer based upon packet transmission utilization and packet consumption acknowledgment.

Abstract: A communications transceiver for transmitting and receiving coded communications, with the coding corresponding to a low-density parity check code, is disclosed. A set of available code word lengths and code rates are to be supported by the transceiver. These available code word lengths and code rates are implemented as a subset of starting code word lengths, which are length-reduced by shortening and puncturing selected bit positions in the starting code word length to attain the desired one of the available code word lengths and code rates. The bit positions to be shortened and punctured are selected in a manner that avoids interference between the shortened and punctured bit positions, and that attains excellent code performance.

Abstract: A novel apparatus and method of packet re-sequencing applicable to systems wherein packets are assigned sequence numbers and transmitted over multiple channels with the requirement they be re-ordered at the receiving side. The mechanism is particularly suitable for use in cable systems adapted to implement the DOCSIS 3.0 specification which permits the bonding of a plurality of downstream channels into a single virtual high data rate pipe. In operation, received packets are stored in a memory whereby a pointer to the memory storage location is written into a context table diagram in accordance with the sequence number extracted from the packet. Packets are released in sequence order regardless of the order in which they were received.

Abstract: A novel apparatus for and a method of data transmission whereby an input data stream is distributed over a plurality of physical channels within a logical channel group. Transmission of data over the channel group appears as transmission over a single logical channel having a bandwidth approximately equal to the sum of the physical channel bandwidths. The physical channels making up the logical channel group may have different bandwidth capacities. The invention comprises a method of data unit distribution among a plurality of physical channels including the consideration of the bandwidth capacities of the individual physical channels in implementing the distribution algorithm, and the capability of reproducing the order of the transmission of the data units on the receiving side without the need for additional fields or modification of existing fields of the data units.

Abstract: A novel mechanism for detecting the presence of powered devices over a network. A unique, infinite pseudo-random sequence of pulses are generated and transmitted over the network to the link partner attached to the other end of the cable. At each time unit, the PSE decides whether or not to transmit a pulse at that time. Thus, the pulses generated have pseudo-random inter-pulse delays between them. In addition, each pulse is pseudo-randomly selected to have either positive or negative polarity. If the link partner is a powered device it will be in loopback mode and the transmitted pulses will be looped back to the transmitter (i.e. the PSE). The PSE, at each time unit regardless of whether or not a pulse was transmitted, opens a search window in which it listens to the RX line for the appropriate expected behavior. If a pulse was transmitted, the PSE expects to see a pulse looped back. Similarly, if no pulse was transmitted, the PSE does not expect to receive a signal during the search window.

Abstract: A novel and useful synchronization mechanism that functions to provide a uniform time base for mesh points in a WLAN mesh based network. The invention enables timing synchronization to a common reference clock base by advertising the common TSF within beacon transmissions. All MPs in a mesh share a common DTIM interval. The synchronization mechanism enables the mesh points to avoid collisions in the generation and transmission of beacons. The TBTT offsets of the current MP and its neighbors are advertised in beacons so that neighboring MPs that hear the beacons can select non-overlapping TBTT offsets. Each MP receives one or more beacons from its neighbors and compares the timing of its neighbors to that of itself and adopts the highest TSF (i.e. the fastest) in the mesh. Eventually, all MPs in the mesh will adjust their timing to that of the MP with the fastest clock. The reception of beacons by MPs from its neighbors is also advertised.

Abstract: A DSL modem (21) including a configurable digital transceiver (30) is disclosed. The digital transceiver (30) includes a configuration register (43), or other circuitry, that selects a number of analog transmission ports to be implemented in the modem (21). Instances of analog front-end circuitry (34) for each of the configured ports is also provided. According to the disclosed embodiments, the number of ports supported is scaled with the data rate for each port, and with the signaling bandwidth for each port, to maximize the efficiency of the transmission.

Abstract: Generating an output signal having a frequency of 1/(M+F) of the frequency of the input signal, wherein M represents an integer and F represents a non-zero fraction. Assuming F equals (Q/R) in one embodiment, wherein Q and R are integers, R intermediate signals phase shifted by equal degree (relative to the one with closest phase shift) in one clock period of the input signal are generated. A selection circuit may select one of the intermediate signals in one clock cycle, select the successive signals with increasing phase shift in Q clock cycles, and leave the intermediate signal with the same shift as in the previous clock cycle in the remaining ones of the M clock cycles. A counter counts a change of state in the output of the selection circuit, and generates a pulse representing an edge of the output signal at the time instance when counter counts M.

Abstract: A client premises digital subscriber line (DSL) modem having multi-mode capability is disclosed. In initialization, the modem estimates whether channel conditions are such that digital processing of the received data according to a lower data rate DSL standard, such as ADSL2, may result in a higher effective data rate than receipt and processing according to a higher data rate DSL standard, such as ADSL2+. If so, the DSL modem configures itself, such as by configuring its filter characteristics and sampling frequency, to receive and process data according to the lower data rate DSL standard; the transmitting modem, for example at a central office or service area interface, may continue to operate according to the higher data rate standard (with its bit loading corresponding to a subset of subchannels). The receiving DSL modem processes the payload data according to the lower standard, while processing control messages according to the higher standard.

Abstract: Prefilters for a receiver with multiple input branches are trained in the frequency domain. The frequency response B of a conditioned channel is determined without reference to the prefilters, and the frequency response W of the prefilters is computed from the frequency response B of the conditioned channel. The prefilters suppress interference.

Abstract: A stage of a pipelined ADC used as a sub-ADC in a time-interleaved ADC is operated using a first set of clock signals, with a next stage being operated using a second set of clock signals. The first set and second set of clock signals are designed to cause the start of hold phases of the stage to occur earlier than the sample phases of the next stage. In an embodiment, the start of the hold phases is coincident with the end of an immediately preceding sample phase of the stage. As a result, more time is provided for the output of an amplifier used in the stage to settle to a final value, thus permitting use of a low speed amplifier and reduction in power consumption in the interleaved ADC. In an embodiment, the stage corresponds to an earliest stage in the pipelined sub-ADC.

Abstract: The present invention provides an encoding method and a class of decoding methods that provide methods for high throughput and high robustness digital communications over channels that are contaminated by impulse noise, as well as white and colored additive noise (noise that is characterized by heavy-tailed distribution), phase noise and signal fading.

Abstract: A receiving modem (20) including functionality for adjusting the synchronization of its timing relative to a transmitting modem (10), by recovering timing from a plurality of pilot tones transmitted by the transmitting modem (10) in a multicarrier modulation signal, is disclosed. For a subset of the pilot tones, the receiving modem (20) sums phase error differences, for example according to a weighted sum, to derive a phase error estimate relative to reference signals, in which noncoherent random noise cancels out, to correct for timing differences between the modems (10, 20). For another subset of the pilot tones not used in the phase error estimate, the receiving modem (20) analyzes the demodulated signal for those tones to adjust reference signals for each of those pilot tones. The adjusting is performed either by deriving an adjusted complex reference signal, or by adjusting coefficients in a frequency domain equalizer (28).

Abstract: According to an aspect of the present invention two streams data encoding corresponding information contained in a multimedia signal are generated with one bitstream (“first stream”) providing for reproduction of the information with a base quality (e.g., according to a corresponding standard), and the second bitstream (“second stream”) containing information which can be used to further enhance the quality of reproduction.

Abstract: A wireless device 10, 12 that distinguishes between multiple piconets is provided. The wireless device 10, 12 includes a preamble component operable to provide a preamble for a wireless fixed frequency interleaving transmission. The wireless device 10, 12 also includes a correlator component operable to distinguish a wireless transmission based on the preamble. The preamble is based on a 128-length sequence 120, 136, 144, formed using a 16-length sequence and a 8-length sequence. The 16-length sequence is selected from the group consisting of a first 16-length sequence 110, a second 16-length sequence 132, and a third 16-length sequence 140. The 8-length sequence is selected from the group consisting of a first 8-length sequence 112, a second 8-length sequence 134, and a third 8-length sequence 144.

Abstract: A device (104, 106, 108) is provided for wireless communication. The device (104, 106, 108) includes a transmitter (200) operable to transmit an orthogonal frequency division multiplex symbol. The orthogonal frequency division multiplex symbol has a first set of copied tones adjacent a first end of the orthogonal frequency division multiplex symbol, a second set of copied tones adjacent a second end of the orthogonal frequency division multiplex symbol, and a plurality of data tones provided between the first and second sets of copied tones. The first and second sets of copied tones include copies of at least some of the plurality of data tones.

Abstract: Embodiments of the invention reduces the computational complexity of adaptive frequency hopping mechanisms while mitigating the effects of interference. Embodiments of the invention can provide structured adapted hopping sequences that reduce transitions between good and bad channels and/or assign good channels to slots where data is to be transmitted and bad channels to idle slots. Embodiments of the can be designed to comply with current FCC regulations, yet remain adaptable to changing rules.

Abstract: A system and method for generating a message integrity code, MIC, for a MAC protocol data unit in a wireless local area network, WLAN, operating according to the IEEE 802.11 standard. A MAC service data unit, MSDU, sequence control sequence number, SN, input to the MIC algorithm is suppressed, e.g. set to all zeros, when calculating the MIC. Only the fragment number, FN, portion of the sequence control is included in calculation of the MIC. The MIC may therefore be calculated before an actual SN has been determined. All MPDUs include sequential packet numbers, PNs. A station receiving MPDUs checks the PNs of MPDUs having the same SN, and rejects messages which do not have a proper sequential set of PNs.