Abstract: System and methods enabling radio communications that are operating in noisy environments using OFDM (Orthogonal Frequency Division Multiplexing) are disclosed. A spread OFDM transmitter that generates OFDM symbols that may include multiple copies of IFFT symbols is disclosed. A spread OFDM receiver is disclosed for receiving the spread OFDM symbols. Other methods for symbol detection, frequency offset correction, and equalization are disclosed.

Abstract: System and methods enabling radio communications that are operating in noisy environments using OFDM (Orthogonal Frequency Division Multiplexing) are disclosed. A spread OFDM transmitter that generates OFDM symbols that may include multiple copies of IFFT symbols is disclosed. A spread OFDM receiver is disclosed for receiving the spread OFDM symbols. Other methods for symbol detection, frequency offset correction, and equalization are disclosed.

Abstract: An electrical wire includes a core comprising an electrically conductive material that conducts electricity along the length of the electrical wire. The core also includes an acoustic conductive material that conducts acoustic waves along the length of the electrical wire. The core also includes an acoustic waveguide that provides internal reflection for the acoustic waves conducted through the core, and that guides the acoustic waves along the length of the electrical wire. The response acoustic wave signals may be compared against a failure model for the wire in order to determine the reliability of the electrical wire.

Abstract: A system and method for tracking a person using a deduced reckoning device is disclosed. The method includes the operation of selecting an initial location of the person. The person's movement along a path is then monitored using directional sensors, including a digital magnetic compass, at least one accelerometer, at least one magnetometer, at least one gyroscope, and an altimeter. The person's changing location is recorded based on a change in outputs of the directional sensors that occur during the person's movement. The person's changing location is transmitted to a command and control center. The person's changing location is then displayed on a graphical user interface at the command and control center.

Abstract: A LAN adapter device using an interpolative equalizer. The LAN adapter device allows LAN computing devices to connect to the LAN medium. The adapter devices are internal or external to the LAN devices and provide a transceiver and protocol stacks for the LAN devices to communicate with each other. The physical layer of the transceivers includes transmitter having a DMT modulator and demodulator that is dynamically configurable with respect to data rate and spectrum usage. Within the receiver is an equalizer that equalizes the received signal with a simple yet effective equalizer training method, thereby obviating the need for extensive equalizer training and long-term coefficient storage. The equalizer trains on known symbols transmitted on specific carriers that arc spaced apart in the frequency domain and then determines the channel response at those frequencies.

Abstract: A correlator for use in a timing recovery apparatus of a receiver in a multicarrier transmission system. The correlator locates the beginning of a data frame and initializes a pointer register with an address to a location within the receive signal buffer. Data is transferred to a signal converter from the receive signal buffer where the samples that are fed into the converter are determined by the address stored in the pointer register.

Abstract: A gateway modem server device for a home LAN. The modem server includes a first transceiver that utilizes DMT modulation methods for communication over the local LAN, and a second transceiver for communication with the access infrastructure that utilizes POTS telephone services. The LAN devices connected to the LAN access the modem server via LAN adapter devices. The adapter devices are internal or external to the LAN devices and provide a transceiver and protocol stacks for the LAN devices to communicate with each other. The physical layer of the transceivers includes transmitter having a DMT modulator and demodulator that is dynamically configurable with respect to data rate and spectrum usage. The devices communicate with the modem server and the modem server communicates to the POTS service provider over the same medium.

Abstract: The subject invention defines the details of packet based DSL modulation. The invention claims a method for minimizing crosstalk generation by specifying a duty cycle for bursted carrier data traffic and a method of providing opportunistic echo canceller training. In this way the present invention minimizes power and interference while maximizing the peak capacity of a transceiver used in ADSL communication systems.

Abstract: A low-complexity frequency domain equalizer having fast re-lock capabilities for use in a DMT transceiver. The transceiver includes a modulator that utilizes DMT modulation methods for communication over the transmission medium, a demodulator for receiving DMT signals, and a channel equalizer that operates in the frequency domain. The equalizer models the channel characteristic as an FIR filter that distorts the signal transmitted over the channel. The channel distortion is removed at the receiver by performing a de-convolution of the channel response via a frequency domain multiplication. After a period of inactivity of the receiver, the equalizer taps are updated by the use of a fast re-lock method so that the previously trained equalizer may be utilized. An undetermined sampling time offset is determined and is used to update the equalizer coefficients such that a full retraining of the equalizer is not required.

Abstract: A LAN Adapter device having a frequency domain equalizer. The LAN adapter device allows LAN computing devices to connect to the LAN medium. The adapter devices are internal or external to the LAN devices and provide a transceiver and protocol stacks for the LAN devices to communicate with each other. The physical layer of the transceivers includes transmitter having a DMT modulator and demodulator that is dynamically configurable with respect to data rate and spectrum usage. Within the receiver is an equalizer for equalizing the received signal with a simple yet effective equalizer training method, thereby obviating the need for extensive equalizer training and long-term coefficient storage. The equalizer trains on known symbols transmitted in one frame of a transmitted packet to determine an estimate of the channel response.

Abstract: A low-complexity frequency domain echo canceller for use in a full-duplex DMT transceiver. The transceiver includes a modulator that utilizes DMT modulation methods for communication over the transmission medium, a demodulator for receiving DMT signals, and a frequency domain echo canceller for removing echoes of the transmitter's signal from the receive signal. The echo canceller models the echo channel characteristic as an FIR filter that distorts the transmitted signal that is received by the receiver section of the full-duplex transceiver. The echo is removed from the received signal by determining the frequency domain characteristic of the echo channel. A local replica of the echo is generated in the frequency domain using the echo characteristic and is subtracted from the frequency domain representation of the received signal.