Abstract: A transmission system for transmitting data as part of a communications system, the data comprising a plurality of data symbols or elements, the transmission system being configured to divide the data into at least a first data portion and a second data portion, wherein the first data portion is communicated by transmitting signals in selected carrier channels, wherein the transmission system is configured to encode at least one data symbol or element by selecting a relative order of at least one first carrier channel having a first operational state and at least one second carrier channel having a second operational state.

Abstract: A transmission system for transmitting data as part of a communications system, the data comprising a plurality of data symbols or elements, the transmission system being configured to divide the data into at least a first data portion and a second data portion, wherein the first data portion is communicated by transmitting signals in selected carrier channels, wherein the transmission system is configured to encode at least one data symbol or element by selecting a relative order of at least one first carrier channel having a first operational state and at least one second carrier channel having a second operational state.

Abstract: A method and associated transmission system, signal processor and communications system for converting a signal from a bipolar signal Into a unipolar signal, the method involving applying a pulse shaping filter to the bipolar signal to produce a pulse shaped bipolar signal; and subsequently transforming the negative values of the pulse shaped bipolar signal to produce the unipolar signal. Preferably, the bipolar signal and/or the shaped bipolar signal and/or the unipolar signal have a plurality of frames, and the frames have at least one guard interval, wherein the guard interval(s) include a prefix provided before or at the start of at least one frame and/or a suffix provided after or at the end of at least one frame.

Abstract: An approach for scheduling users in a cellular environment such that a Pareto optimal power control can be applied, wherein in each cell of the cellular environment there are a plurality of user, includes scheduling users such that a number of groups of interfering users from different cells which fulfill a feasibility condition for the Pareto optimal power control is maximized.

Abstract: A method for scheduling users in a cellular environment such that a Pareto optimal power control can be applied, includes determining whether a set of users in the cellular environment fulfills a feasibility condition for the Pareto optimal power control, and in case the feasibility condition for the Pareto optimal power control is not fulfilled, modifying the SINR targets of the users such that the feasibility condition for the Pareto optimal power control is fulfilled.

Abstract: Acoustic telemetry devices and methods that provide directional detection. In one embodiment, a disclosed acoustic telemetry device comprises at least two acoustic sensors and an electronics module. The electronics module combines the detection signals from the acoustic sensors to obtain a combined signal that substantially excludes signals propagating in a direction opposite to the communication signal. The disclosed systems and methods can be trained in the field and will readily accommodate an irregular and unknown signal transmission medium between the two acoustic sensors.

Abstract: A signal analyzer includes a divergence detector for detecting periodic interference in a signal, an information detector for detecting a random event in the signal, and output circuitry for providing compensation for the periodic interference and the random event.

Abstract: Acoustic telemetry devices and methods that provide directional detection. In one embodiment, a disclosed acoustic telemetry device comprises at least two acoustic sensors and an electronics module.

Abstract: Acoustic telemetry devices and methods that provide directional detection. In one embodiment, a disclosed acoustic telemetry device comprises at least two acoustic sensors and an electronics module. A first of the acoustic sensors detects a communication signal that propagates along a tubing string in a first direction. A second of the acoustic sensors is configured to detect the communication signal before the first acoustic sensor. The electronics module combines the detection signals from the acoustic sensors to obtain a combined signal that substantially excludes signals propagating in a direction opposite to the communication signal. Such signal suppression may significantly enhance the communication signal's signal-to-noise ratio, thereby increasing channel capacity. The acoustic telemetry device may be configured to support logging while drilling and/or full-duplex communication.

Abstract: Acoustic telemetry devices and methods that provide directional detection. In one embodiment, a disclosed acoustic telemetry device comprises at least two acoustic sensors and an electronics module. A first of the acoustic sensors detects a communication signal that propagates along a tubing string in a first direction. A second of the acoustic sensors is configured to detect the communication signal before the first acoustic sensor. The electronics module combines the detection signals from the acoustic sensors to obtain a combined signal that substantially excludes signals propagating in a direction opposite to the communication signal. Such signal suppression may significantly enhance the communication signal's signal-to-noise ratio, thereby increasing channel capacity. The acoustic telemetry device may be configured to support logging while drilling and/or full-duplex communication.