Abstract: A method, device and network (100, 200) for compressing cable modem data signals and conserving bandwidth within the network. Cable modems (110, 210) transmit upstream data signals to a fiber node (130, 230) which compresses the data signals and transmits the compressed signals upstream to a headend (112, 212) which decompresses the data signals. The fiber node (130, 230) compression may be by a shaping filter (142, 144) or a fast Fourier transform (FFT) function 270. The headend decompression may be by an inverse shaping filter (162) or an inverse FFT function (272).

Abstract: A data packet type communication system utilizes packet framing wherein preambles are split into tow or more subpreambles, separated by a number of data or a priori known symbols. A receiver chooses among individual and combined subpreamble options for determining synchronization. When a noise impulse prevents detection of one subpreamble, the impulse is detected, and preamble correlation proceeds using an unaffected subpreamble. When no impulse is detected, combined subpreambles are used.

Abstract: A method, device and system are provided for a physical layer for a CATV upstream channel. A group of features is provided to address increased capacity and robustness to noise, while at the same time keeping cost and complexity to a minimum. Other methods and systems are also provided.

Abstract: The present invention comprises aggregating a plurality of physical channels to a single logical channel, a scalable virtual channel (SVC). This may be implemented in a point to multipoint communications system. The present invention enables a variety of receivers, some receivers being able to receive only one physical channel, and other receivers being able to receive a plurality of physical channels as a SVC, with at least one same channel being used for both types of receivers.

Abstract: A data communication method and system are provided for communications over a channel that consists of multiple sub-channels. A data communication system is provided with a transmission channel having transmission sub-channels for transmitting and receiving data, the system comprising: a first terminal for transmission of data on one or more of a first plurality of sub-channels; a second terminal for transmission of data on one or more of a second plurality of sub-channels wherein the first plurality of sub-channels and the second plurality of sub-channels are partially overlapping such that at least one sub-channel is shared by the first terminal and the second terminal and at least one sub-channel is not shared by the first terminal and the second terminal; and a control mechanism for allocating data transmission between the sub-channels. A method of data transmission in a communication system is also provided. Other methods and systems are also provided.

Abstract: A method and device (100, 200) for combining digital data signals, converting them to analog data signals, and transmitting the analog signals downstream via a single up converter (170, 270). The data transmission method includes generating a plurality of digital signals, digitally combining the digital signals, and converting the combined digital signal to an analog signal. The analog signal is up converted to a transmittable analog signal having a frequency suited for transmission along a particular transmission medium, and the transmittable analog signal is transmitted. The data transmission device (100, 200) includes a digital combiner circuit (180, 182, 282), a D/A converter (150, 152, 250), an up converter (170, 270), and an optional analog combiner circuit (190).

Abstract: A data communication method and system are provided for preserving quality of service throughout the system. A data communication system is provided that comprises: a first manager for allocating a first time slot to a first network; and a second manager for allocating a second time slot to a second network such that one of the first time slot or the second time slot begins a short time before the other of the first time slot or the second time slot begins wherein data is transmitted between the second network and the first network during the first time slot or the second time slot. Other methods and systems are also provided.

Abstract: An adaptive equalizer capable of tracking rapid channel variations while maintaining high stability and low jitter, and a receiver constructed therefrom. A novel feature of the invention is that is that the equalizer is sectioned, that is constructed from a plurality of feed-forward sections and decision-feedback sections, where these sections comprise a cascade of an adaptive linear filter and an adaptive multiplier. This structure is effective at combating rapid channel variations, which are a result of delay variations of the reflections of the signal, e.g., airplane flutter, without sacrificing the stability and the accuracy of the equalizer even in cases where the equalizer has a large number of taps. The different equalizer sections may have different step size parameters. A controller monitors the channel variations and adjusts the step size parameters of each section accordingly.

Abstract: A technique that combines a turbo trellis coded modulation (TTCM) coding scheme with constellation shaping and precoding schemes to implement a binary coded communication system and method that can achieve high performance (high coding gains achieved in combination with shaping gain, and when necessary, also with high performance in ISI-channels via preceding).

Abstract: A home networking transmitter (100), receiver (200), station (300), network manager(404), network (400) and method adapted to network devices (344/336/338/346) over phone lines (406) in a home. A bandwidth other than the 4 to 10 MHz band defined in the HomePNA 2.0× specification and a Baud rate higher than 4M baud may be used for communications between a plurality of devices (334/336/338/346). PHY and MAC layers are improved to increase the performance of home phone line networks. Advantages in the PHY layer include numerous higher symbol rates, higher constellations, variable power level, error correcting codes, byte interleaving, ISI-free pulse shape and pre-equalization. Advantages in the MAC layer include managed bandwidth resources allocation, guaranteed quality of service for latency sensitive applications, solicited grants, support to devices with low power consumption and support to device with low processing power.

Abstract: An adaptive equalizer capable of tracking rapid channel variations while maintaining high stability and low jitter, and a receiver constructed therefrom. A novel feature of the invention is that is that the equalizer is sectioned, that is constructed from a plurality of feed-forward sections and decision-feedback sections, where these sections comprise a cascade of an adaptive linear filter and an adaptive multiplier. This structure is effective at combating rapid channel variations, which are a result of delay variations of the reflections of the signal, e.g., airplane flutter, without sacrificing the stability and the accuracy of the equalizer even in cases where the equalizer has a large number of taps. The different equalizer sections may have different step size parameters. A controller monitors the channel variations and adjusts the step size parameters of each section accordingly.

Abstract: The present invention provides low complexity methods and apparatus for improving the performance of conventional QAM modulations. These methods provide (a) larger noise margins than conventional constellations and/or (b) improved labeling schemes. Additionally, the invention provides fixed-point approximations of these constellations to allow for low complexity VLSI implementations of these schemes.

Abstract: A receiver for digital signals is provided having a) a front end unit for receiving an analog signal which is encoded with data redundancy, for down-converting said signal using a provided estimated carrier frequency, for filtering out of band signals and for generating a sequence of samples at a sampling rate using a provided estimated symbol rate; b) a synchronization unit for generating an estimated carrier frequency and an estimated symbol rate for the received signal; c) an equalizer and detector unit for receiving the output of the front end unit, for compensating for possibly time varying inter-symbol-interference, phase noise, carrier and symbol timing offsets, AM hum, filtering noise and interference, and detecting the transmitted data, which includes: i) a forward filter for receiving the output of the front end unit, for performing a linear filtering operation using a filter with adjustable parameters and for generating an estimated symbol sequence at the estimated symbol rate, ii) a phase rotator

Abstract: An adaptive equalizer capable of tracking rapid channel variations while maintaining high stability and low jitter, and a receiver constructed therefrom. A novel feature of the invention is that is that the equalizer is sectioned, that is constructed from a plurality of feed-forward sections and decision-feedback sections, where these sections comprise a cascade of an adaptive linear filter and an adaptive multiplier. This structure is effective at combating rapid channel variations, which are a result of delay variations of the reflections of the signal, e.g., airplane flutter, without sacrificing the stability and the accuracy of the equalizer even in cases where the equalizer has a large number of taps. The different equalizer sections may have different step size parameters. A controller monitors the channel variations and adjusts the step size parameters of each section accordingly.

Abstract: A single transducer digital communication receiver is described which is capable of extracting the data bits of at least one desired signal in the presence of interfering signals of similar type. The present invention also seeks to provide a communication system in which overlapping transmissions are tolerated and allowed. The present invention describes a design for a digital communication system, according to a specific frequency plan, which includes an appropriate digital demodulator that extracts the data bits of the desired signal(s) in the presence of closely spaced signals. The present invention enables reduced channel spacing in digital communication systems and thereby increases the system capacity (i.e. the number of users per bandwidth unit) without incurring any significant loss in system performance (e.g. power margins, BER, and channel availability). It also allows a reduced power margin that is required to maintain a pre-specified performance level without sacrificing system capacity.

Abstract: A method and apparatus for controlling an equalizer receiving the output of an unknown system in order to produce a desired response for recovering the input to the system are characterized by iteratively adjusting the equalizer such that the unknown system combined with the equalizer behaves essentially as a linear system whose (t,n) taps, for some combinations of t and n, are iteratively adjusted according to the following rule: ##EQU1## where s.sub.t,n denotes the (t,n) tap before the iteration, s'.sub.t,n denotes the (t,n) tap after the iteration, I is a preselected integer greater then or equal to one, .alpha..sub.i i=1,2 . . . I are preselected scalars that may vary from iteration to iteration, and p.sub.i, q.sub.i i=1,2, . . . I are preselected non-negative integers such that p.sub.i +q.sub.i .gtoreq.2.