Abstract: Digital signal processing for mud pulse telemetry utilizes a variety of “On/Off” keying based modulation schemes, such as pulse width modulation (PWM) and pulse position modulation (PPM), to encode and/or decode information. A combination of PPM and PWM is disclosed that increases a bit rate while keeping a chip rate unchanged. The combination of PPM and PWM comprises determining a drilling condition and forming a message based on the drilling condition, forming a string of symbol values comprising the message, identifying a pulse width and a pulse start for the pulse based on a symbol value, providing a first pulse at a selected chip location, providing subsequent pulses to form the pulse width, and forming a quiet period at the end of the pulse width.

Abstract: Digital signal processing for mud pulse telemetry utilizes a variety of “On/Off” keying based modulation schemes, such as pulse width modulation (PWM) and pulse position modulation (PPM), to encode and/or decode information. A combination of PPM and PWM is disclosed that increases a bit rate while keeping a chip rate unchanged. The combination of PPM and PWM comprises determining a drilling condition and forming a message based on the drilling condition, forming a string of symbol values comprising the message, identifying a pulse width and a pulse start for the pulse based on a symbol value, providing a first pulse at a selected chip location, providing subsequent pulses to form the pulse width, and forming a quiet period at the end of the pulse width.

Abstract: Systems and methods for digital signal processing are provided. A method includes mapping a symbol in a pulse sequence by using a pulse width and a pulse start in the symbol, reading a message using a symbol value for each symbol in a string of symbols, and modifying a drilling configuration according to the message. A device configured to perform the above method is also provided.

Abstract: Systems and methods for filtering pump interference in mud pulse telemetry are provided. A method includes receiving a monitor output, selecting an adaptive factor in an adaptive filter module, and adjusting the adaptive factor when the adaptive filter module has reached convergence. The method may further include receiving a sensor input, providing a filtered signal output, and modifying a drill configuration based on the signal output. A system configured to perform the method above is provided. A method as above further including modifying a drill configuration based on the signal output is provided.

Abstract: A system can include a well tool operable to transmit a fluid through an interior of the well tool. The system can also include a transmitter coupled to the well tool. The transmitter can select a parameter of a pressure waveform using a Gray code that corresponds to the parameter and generate the pressure waveform in the fluid.

Abstract: A method and system of mud pulse telemetry uses a preamble having a number of periods of a synchronization sequence followed by a single period of a channel estimation sequence. The synchronization may be characterized by a generally flat frequency spectrum, and the channel estimation sequence may be characterized by a low cross-correlation with said synchronization sequence. The sequences may be generated from a set of nonrepeating discrete sequences. The preamble may be suitable for both sequence detection and channel estimation, satisfy all the physical and/or electronic constraints of the system, and allow for fast convergence of an adaptive channel tracking or equalization system.

Abstract: Systems and methods for filtering pump interference in mud pulse telemetry are provided. A method includes receiving a monitor output, selecting an adaptive factor in an adaptive filter module, and adjusting the adaptive factor when the adaptive filter module has reached convergence. The method may further include receiving a sensor input, providing a filtered signal output, and modifying a drill configuration based on the signal output. A system configured to perform the method above is provided. A method as above further including modifying a drill configuration based on the signal output is provided.

Abstract: A method and system of mud pulse telemetry uses a preamble having a number of periods of a synchronization sequence followed by a single period of a channel estimation sequence. The synchronization may be characterized by a generally flat frequency spectrum, and the channel estimation sequence may be characterized by a low cross-correlation with said synchronization sequence. The sequences may be generated from a set of nonrepeating discrete sequences. The preamble may be suitable for both sequence detection and channel estimation, satisfy all the physical and/or electronic constraints of the system, and allow for fast convergence of an adaptive channel tracking or equalization system.

Abstract: A system can include a well tool operable to transmit a fluid through an interior of the well tool. The system can also include a transmitter coupled to the well tool. The transmitter can select a parameter of a pressure waveform using a Gray code that corresponds to the parameter and generate the pressure waveform in the fluid.

Abstract: Systems and methods for digital signal processing are provided. A method includes mapping a symbol in a pulse sequence by using a pulse width and a pulse start in the symbol, reading a message using a symbol value for each symbol in a string of symbols, and modifying a drilling configuration according to the message. A device configured to perform the above method is also provided.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may operate to transform acquired data into transformed data using at least one transform selected from a plurality of transforms according to an optimization metric calculation that operates on single, fixed-length packets of the transformed data, and a preselected quality criterion threshold. Further activity may include transmitting an amplified version of an electrical signal in a geological formation, the electrical signal including the transformed data. The amplified version may be received, and further activity may include transforming the transformed data into an estimate of acquired data, the transforming using at least one transform selected from a plurality of transforms according to an optimization metric calculation that operates on single, fixed-length packets of the transformed data and/or the estimate, and a preselected quality criterion threshold. Additional apparatus, systems, and methods are disclosed.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may operate to determine a uniform number of bits per sub-carrier and an error correction rate as part of a communication system configuration to maximize the effective bit transmission rate while minimizing the size of the configuration description, using a predetermined number of bits. The configuration description designates at least the number of bits per sub-carrier, the error correction rate, and the number of sub-carriers. Additional apparatus, systems, and methods are described.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may operate to transform acquired data into transformed data using at least one transform selected from a plurality of transforms according to an optimization metric calculation that operates on single, fixed-length packets of the transformed data, and a preselected quality criterion threshold. Further activity may include transmitting an amplified version of an electrical signal in a geological formation, the electrical signal including the transformed data. The amplified version may be received, and further activity may include transforming the transformed data into an estimate of acquired data, the transforming using at least one transform selected from a plurality of transforms according to an optimization metric calculation that operates on single, fixed-length packets of the transformed data and/or the estimate, and a preselected quality criterion threshold. Additional apparatus, systems, and methods are disclosed.

Abstract: Systems and methods for achieving a maximum bit rate in a Discrete MultiTone (DMT) system using a quad spectrum under constraints of avoiding interference with radio frequency interference (RFI) are described. At least one embodiment utilizes bins in notched areas for transmission over short loops without violating the power spectral density (PSD) mask in order to optimize bit allocation.

Abstract: A method and system for achieving a maximum bit rate in a DMT system using a quad spectrum under constraints of avoiding interference with radio frequency interference (RFI). The methods of an embodiment of the present invention, when combined in various combinations, optimize bit allocation and utilizes bins in notched areas for transmission over short loops without violating the power spectral density (PSD) mask.

Abstract: In accordance with one aspect of the invention, an apparatus is provided having a transmit path and a receive path for communicating data. The apparatus includes an analog to digital (A/D) converter that is disposed in communication with the receive path. The A/D converter operates at a first sampling rate, and it converts a received analog signal into a digital signal. The apparatus also includes a first echo canceller that is in communication with the receive path and that operates at the first sampling rate for estimating a first portion of an echo signal leaking from the transmit path to the receive path. The estimated echo signal is subtracted from the digital signal. The amplitude of the digital signal is increased by a digital gain. A decimator is disposed in communication with the receive path, whereby the decimator filters the digital signal that has a first sampling rate and emits a signal output at a reduced sampling rate.