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:
A method of adaptive error correction coding includes processing data during a connection between a transmitting entity and a receiving entity, where the data is processed in accordance with a predetermined coding scheme. More particularly, processing data can include encoding one or more sequences received by an error correction encoder of the transmitting entity, or decoding one or more block codes received by an error correction decoder of the receiving entity. During the connection, then, the method can include selecting or receiving a selection of feedback code information. Thus, during at least a portion of the connection, the data processing can be switched to processing data in accordance with a parity-check coding technique based upon the feedback code information.
Abstract:
Disclosed is an OFDM communications system and a method of operating the OFDM communications system. The system includes an OFDM transmitter for transmitting data over a plurality of OFDM sub-channels, where the OFDM transmitter has a plurality of modulators of different types. The system further includes an OFDM receiver for receiving the data from the plurality of OFDM sub-channels, where the OFDM receiver has a plurality of corresponding demodulators of the different types. The system further includes, in accordance with this invention, an adaptive learning automata that contains a group or team of independent, decentralized automaton operating in accordance with a game theory-based approach. Each of the plurality of automaton are responsible for managing one MCS switching threshold value so as to maximize at least one selected performance criterion. The OFDM transmitter is responsive to the MCS switching thresholds for selecting an appropriate one or ones of said modulators for modulating the data for various ones of the sub-channels.
Abstract:
A multiple-access communications downlink uses OFDM and error-correcting codes to send data to multiple terminals from a single access point, in which packets of message information for multiple users are aggregated (405) and encoded (410) into a single error-correction codeword, in which assigned time slots corresponding to specific OFDM symbols are used to separate different users, so that a near-capacity achieving channel coding system constructs a single codeword for use with iterative decoding architectures at the mobile terminals.
Abstract:
A network entity in a multi-transmit antenna system, such as a transmitting or receiving entity, includes a component such as a pre-coder or a receiver, and is configured for full-spatial-rate coding data. The network entity is capable of providing a full-spatial-rate codebook having been designed by selecting an underlying partial-spatial-rate codebook designed for a system configured for partial-spatial-rate coding data. The full-spatial-rate codebook can then be designed in a manner including defining the full-spatial-rate codewords based upon partial-spatial-rate codewords of the partial-spatial rate codebook and basis vectors of a null space of the respective partial-spatial-rate codewords in a multidimensional vector space. The network entity can also be capable of selecting codewords of the codebook in accordance with a sub-space tracking method whereby the codewords of the codebook can be selected in a manner that exploits correlations therebetween.
Abstract:
Puncture sequences S 1 , S 2 , etc. for code rates R 1 , R 2 , etc. less than a maximum code rate R max are defined subsets of a maximum rate puncture sequence S max that corresponds to the maximum code rate R max . Each puncture sequence S i for a code rate R i is related to the puncture sequence S i-1 of the previous code rate R i-1 and preferably S 1 ⊆S 2 ⊆...⊆S max - 1 ⊆S max . The puncture sequences are groups of one or more memory elements, each of which is a variable degree, a variable node location, a check degree, or a check node location. A method for deriving such a puncture sequence for variable code rates is also disclosed.
Abstract:
An illustrative seismic while drilling system includes a drill string having at least one seismic sensor that can be employed to detect seismic signals during pauses in the drilling process, e.g., when extending the length of the drill string. An embedded processor digitizes a signal from the seismic sensor to obtain a digital waveform and processes the digital waveform to derive a compressed waveform representation for storage or transmission. Compression is provided by adaptively reducing the sampling rate and quantization resolution subject to one or more quality constraints including, e.g., error in first break timing, error in first break sign, mean square error, and bit count. Reasonably good representations of the received acoustic waveforms can be achieve with less than 200 bits.
Abstract:
A system, transmitter, receiver, method, and computer program product are provided in which a plurality of structured interleavers permute data bits arranged in a data bit matrix for Zigzag encoding. For each interleaver, the data bits in each column of the data bit matrix are cyclically shifted, with the amount of the shift being predefined and different for each column. In addition to the cycle shift, each column may be bit reverse ordered, and entire columns may be swapped. The interleaved data bit matrix may then be encoded using a Zigzag encoder to generate parity bits that may be transmitted, along with the data bits, from a transmitter to a receiver where the data may be iteratively decoded.
Abstract:
A system, transmitter, method, and computer program product apply a performance improvement characteristic, such as phase rotation or power allocation, to both a known preamble and a data payload of a transmitted data packet, such that existing multi-carrier receivers are capable of decoding the data payload with the performance improvement characteristic applied. The performance improvement characteristic is applied by vector-matrix multiplication of the preamble and the data payload by the performance improvement characteristic.
Abstract:
A method of constructing a puncture sequence includes providing a seed puncture sequence including a plurality of elements. The elements of the seed puncture sequence are based upon non-zero elements of a plurality of columns of a parity-check matrix having a column dimension and a row dimension. In this regard, the parity-check matrix defines an error correction code, and has been constructed based upon a seed parity-check matrix derived from an edge ensemble. After providing the seed puncture sequence, a variable node-puncture sequence can be constructed based thereupon. The variable node-puncture sequence, then, corresponds to a puncture sequence configured for processing an error correction code.