Abstract: The communication device includes a transmitter for transmitting communication signals through a transmitter output terminal, a receiver for receiving communication signals through a receiver input terminal, and a coupling unit for coupling the transmitter output terminal and the receiver input terminal to the shared transmission medium, and including a first filter for passing communication signals from/to the shared transmission medium within a first communication frequency range, and a second filter for passing communication signals from/to the shared transmission medium within a second communication frequency range disjoint from the first communication frequency range.

Abstract: A novel method of operating a Distributed Cable Modem Termination System is provided. Each branch CMTS node in a distributed CMTS supports a complete CMTS system and with full-spectrum ports. One or more MAC domains are defined at each branch CMTS node. A MAC domain defined at a branch CMTS node includes only service flows of the CMs that are connected to the branch CMTS node. Identifiers of service flows coming from a branch CMTS node are always unique, i.e., two different service flows of the branch CMTS would always have different SIDs, even if they belong to different MAC domains. On the other hand, service flows belonging to different branch CMTS nodes are free to reuse the same identifiers.

Abstract: In embodiments of the presently described subject matter, two efficient PAPR reduction methods for OFDM signals based upon the principle of tone reservation and building upon the clipping noise analysis presented in “Analysis of clipping noise and tone reservation algorithms for peak reduction in OFDM systems,” L. Wang and C. Tellambura, IEEE Trans. Veh. Technol., vol. 57, pp. 1675-1694, May 2008 are provided, each comprising two stages. The first stage is performed offline to prepare a set of cancellation signals based on the settings of the OFDM system. In particular, these cancellation signals are constructed to cancel signals at different levels of maximum instantaneous power that are above a predefined threshold. The second stage is performed online and in an iterative manner to reduce the peaks of OFDM symbols by using the cancellation signals constructed in the first stage.

Abstract: Example embodiments describe a controller comprising means for performing i) discovering a mapping between receive analogue to digital converters, RxADCs, of a full duplex node (100) and cable modems (111-113, 121-123, 131-133, 141-143) connected to the full duplex node; and wherein the cable modems share a common communication bandwidth; and ii) determining, based on the mapping, sounding groups (152, 162) by grouping cable modems (111-131, 121-123) mapped to a same RxADC (151) into a respective sounding group (152); and wherein a sounding group is indicative for an upper bound of possible interfering cable modems.

Abstract: A multiport FDX data transceiver having (i) digital transmit and receive chains shared by the multiple ports thereof and (ii) a multi-stage echo-cancellation circuit capable of canceling the echo of the transmitted signal that is coupled back into the receive chain through the analog front end of the transceiver. In an example embodiment, the echo-cancellation circuit comprises two stages. The first stage operates to remove a dominant echo signal corresponding to the output signal that is being broadcast on the multiple ports of the transceiver. The second stage operates to remove a residual echo signal typically caused by differences in the pertinent characteristics of the circuits associated with the different ports of the transceiver. In some embodiments, the multi-stage echo-cancellation circuit can be used for training a single-stage echo-cancellation circuit that may be unable to sufficiently quickly converge on an optimal set of filter coefficients on its own.

Abstract: Example embodiments describe a controller comprising means for performing i) discovering a mapping between receive analogue to digital converters, RxADCs, of a full duplex node (100) and cable modems (111-113, 121-123, 131-133, 141-143) connected to the full duplex node; and wherein the cable modems share a common communication bandwidth; and ii) determining, based on the mapping, sounding groups (152, 162) by grouping cable modems (111-131, 121-123) mapped to a same RxADC (151) into a respective sounding group (152); and wherein a sounding group is indicative for an upper bound of possible interfering cable modems.

Abstract: A data transfer system (100) includes a data transmission device (103). The data transmission device can include a data communication circuit (206), a memory (202), and a control circuit (201) operable with the communication circuit and the memory circuit. The control circuit can transfer data (306) to a remote device, establish a sliding window (307) spanning a predetermined amount of data, and store the predetermined amount of data. In response to receiving an error message (311) identifying particular data (312) encountering errors in transfer, the control circuit can retransfer the particular data so long as the particular data is within the sliding window.

Abstract: A remote storage digital video recording system (300) comprises a storage server (310). The storage server can include a memory (412) and a control circuit (410) operable with the memory. The storage server can be in communication across a network (311) with one or more client devices (306,307,308). The control circuit can be configured to create a file allocation table (314) to organize clusters (330) of a computer readable medium (308). The file allocation table can include a plurality of distinguishable file entries (320,321,322). Each of the distinguishable file entries can index clusters of the computer readable medium. At least two of the plurality of distinguishable file entries can index selfsame clusters (331) of the computer readable medium.

Abstract: In a digital communication system there is provided a method for OFDM channel estimation that jointly considers the effects of coarse timing error and multipath propagation. The method uses an iterative channel estimation technique, which considers the practical scenario of fractional timing error and non-sample space echo delays. The method does not require channel state information such as second-order statistic of the channel impulse responses or the noise power. Moreover, timing error can be conveniently obtained with the proposed technique. Simulation shows that, when comparing OFDM channel estimation techniques under DOCSIS 3.1 realistic channel conditions, the proposed algorithm significantly outperforms conventional methods.

Abstract: A server complex (102) includes an interface portal (116). The server complex exposes (401) a generic resource locator (402) pointing to the media content in a generic format at the interface portal. The server complex receives requests for media content (101) from at least a first client device (601) to receive the media content in a first format (603) and at least a second client device (602) to receive the media content in a second format (604). The server complex determines (405), from a header (407) of the request, whether the request is from the first client device or the second client device, generates (409) a response message (108) comprising a manifest file (109) comprising a device specific resource locator (410) pointing to the media content cached (412) in one of the first format or the second format, and transmits (411) the response message to the requesting client.

Abstract: Data samples are filtered by using a digital filter where the length of an impulse response of the digital filter is finite, an impulse response of the digital filter is symmetric and the operation of the digital filter is multi-rate. The method uses a polyphase decomposition to break down the input data stream into N parallel substreams and the multi-rate digital filter is separated by a polyphase decomposition into multiple lower-rate sub-filters where each of the sub-filters is separated into a set of simpler sub-sub-filters which operate upon the same set of input samples and which have impulse responses which are jointly centro-symmetric, a set of pre-filtering arithmetic structures, and a set of post-filtering arithmetic structures and performing each such pair of sub-sub-filtering operations using a single shared filter structure, a set of pre-filtering combining adders, and a set of post-filtering separating adders.

Abstract: A system (100) includes an interface portal (116) to receive (401), at a resource locator (402) pointing to media content (101), a request (117) for the media content from a client device (109). A server complex (102) can validate a secure token (403) of the request, and can issue a new token (405) that includes one or more session identification credentials (406). These can include a session identifier (407) indicating a session required to retrieve the media content to the client device, an identifier of an edge server (105) to serve the request for the media content, and other information. A resource management system (106), operable with the server complex and the edge server, can then throttle a data rate of the session as a function of the one or more session identification credentials or terminate the session as a function of the one or more session credentials.

Abstract: In a digital communication system there is provided a method for OFDM channel estimation that jointly considers the effects of coarse timing error and multipath propagation. The method uses an iterative channel estimation technique, which considers the practical scenario of fractional timing error and non-sample space echo delays. The method does not require channel state information such as second-order statistic of the channel impulse responses or the noise power. Moreover, timing error can be conveniently obtained with the proposed technique. Simulation shows that, when comparing OFDM channel estimation techniques under DOCSIS 3.1 realistic channel conditions, the proposed algorithm significantly outperforms conventional methods.

Abstract: A method used in the receiver of a communication system is provided to suppress narrow band interferences, known as ingress, that are present in the communication channel, which is shared by a plurality of transmitters each having a channel pre-equalizer, by means of a Time Division Multiple Access (TDMA) scheme or Synchronous Code Division Multiple Access (SCDMA) scheme. The method comprises filtering the interferences using Infinite Impulse Response (IIR) notch filters, and providing IIR all-pass filters devised to compensate for substantially all phase distortions introduced by the notch filters. The method also includes an algorithm to detect the narrow band interferences and an adaptive equalizer to equalize the channel by computing the coefficients of the transmitters' pre-equalizers, and arranged such that the equalization of the channel is isolated from the suppression of the interferences.

Abstract: A method of channel processing is provided wherein multiple reduced-bandwidth “processing blocks” may be combined at RF to allow for the continuous and flexible placement of multiple-channels across the full or partial CATV output band. Each reduced-bandwidth processing block is associated with a fixed-frequency upconversion. In order to allow for continuous agile channel placement, the processing blocks overlap one another in frequency at RF. In the case where it is not necessary that the full CATV band be available to the combined output, the number of required processing blocks and upconversion paths is reduced and individual processing blocks and upconversion paths may be used to cover multiple non-contiguous frequency bands.

Abstract: In a DOCSIS transmission network, it is necessary for an upstream receiver to estimate and correct for errors in the carrier frequency of the transmission based upon observations of a preamble sequence. This task is complicated by the fact that microreflections in the upstream channels cause intersymbol interference, which tends to bias the frequency estimation circuit. An economical, ISI-immune algorithm is provided for estimating the carrier frequency of upstream transmissions. The arrangement improves the reliability of the frequency estimates in the presence of ISI, thereby reducing the overhead and increasing the throughput of the upstream channels.

Abstract: A method of channel-to-port assignment is described where the distribution of channels is performed in the digital domain of the CATV/QAM upconverter/modulator. This channel distribution allows for the possibility of simple failover, power combining of multiple outputs, and a fine granularity of channel to port mapping, QAM or analog channel, in a multi-port device.

Abstract: In a method of digital communication where the transmitter includes a pulse-shaping filter and the receiver includes a plurality of corresponding matched filters, the pulse shaping filter is approximated to match a plurality of filters of the receiver for reducing the number of transmit shaping filters. The filter comprises a square-root raised cosine (SRRC) filter where the SRRC filter amplitude/phase response is approximated using a typical Parks-McClellan (remez) algorithm for designing linear phase FIR filters which, for a given set of input parameters, outputs a transmit filter coefficient set for the SRRC filter. The input parameters to the Parks-McClellan algorithm are chosen by iteration such that pass-band ripple, 3-dB point, and stop-band attenuation of the transmit filter meet or exceed specification requirements while the resulting transmit-receive filter pair ISI is minimized across a plurality of matched filter specifications.

Abstract: A distortion-cancellation method for analog CATV or QAM transmission over cable is provided wherein a single feedback path from the output of a multiple-channel multiple-port upconverter/modulator is down-converted and used to reduce or cancel undesirable noise components including LO leakage, spurious, and modulated noise. The method allows for real-time monitoring, tuning, or control of the CATV/QAM output and of interfering signals and aging effects as compared to a desired performance metric.

Abstract: In an RF signal transmission network such as the reverse channels of a coaxial cable network, there is provided at least one adaptive equalizer for pre- or post-filtering inter-symbol interference in the transmitted signals, the adaptive equalizer having a series of coefficients for which values are required. In order to improve the transmission efficiency the preamble used in these channels is shortened by coarsely estimating the channel using a short “unique word’ placed at the beginning of the equalizer training sequence. The coarse channel estimate is crudely inverted to produce a set of equalizer coefficients which partially equalize the channel. By initializing the adaptive equalizer with these approximate coefficients, it is possible to reduce the length of the training sequence needed for the equalizer to converge.