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: Evaluating wellbore telemetry systems. Multiple evaluation signals are serially transmitted to multiple serially connected components of a wellbore telemetry system disposed in a wellbore. Each component is addressable by a respective one of the multiple evaluation signals. In response to serially transmitting the multiple evaluation signals, multiple communication links to the multiple components are evaluated based on a respective multiple responses to the multiple evaluation signals.

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: Methods, apparatus and computer program products are provided for encoding and/or decoding a data block. The method for encoding a data block includes the steps of: providing an information block of size k, I=(i0, i1, . . . i(k?l); and encoding the information block into a low-density parity-check (LDPC) codeword c of size n, c=(i0, i1, . . . i(k?l), p0, p1, . . . , p(n?k?l)), by adding n?k parity bits obtained so that H·cT=0, where H is an (n?k)×n parity-check matrix.

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: Apparatus, and an associated method, for allocating data to communication channels of a multiple-input communication system and to select power levels at which the data is caused to be communicated upon the communication channels. Data allocation is made responsive to communication quality indications that identify communication conditions on the different ones of the channels. Data allocation and power level allocation is made to achieve best a selected performance parameter.

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.

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 includes 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 includes selecting or receiving a selection of feedback code information. Thus, during at least a portion of the connection, the data processing is switched to processing data in accordance with a parity-check coding technique based upon the feedback code information.

Abstract: In a MIMO delay spread (OFDM) system or a MIMO single carrier (non-OFDM) system wherein a transmitter transmits signals to a receiver through multipath fading channels, an equivalent frequency-domain MIMO multipath channel matrix is used to estimate the maximum mutual information regarding the relationship between transmitted signals and received signals. It is possible to compute the upper bound of the maximum mutual information at least based on the total energy of all resolvable paths in the fading channels. The upper bound or the changes in the upper bound can be used to adjust the transmission parameters used in data transmission. The transmission parameters include the modulation order in the modulation process, the code rate and the puncturing rate.

Abstract: A transmitter determines a number of available bits (Navbits) in a minimum number of orthogonal frequency division multiplex (OFDM) symbols in which a data field of a packet may fit, by Navbits=(NCBPS*(1+USTBC))*ceil(Npld/(NCBPS*R*(1+USTBC))), where USTBC equals 1 when Space-Time Block Code (STBC) is used and 0 otherwise, where Npld=LENGTH*8+16, where NCBPS is the number of coded bits per symbol, where R is the code rate, and where LENGTH is a number of bytes in a Physical Layer Convergence Protocol (PLCP) PLCP Service Data Unit (PSDU); and determines an integer number of Low-Density Parity-Check Code (LDPCC) codewords to be transmitted, NCW, and the length of the codewords to be used, LLDPC, from information capable of being expressed in a table format.

Abstract: Fast fading in cellular systems causes time variation of the Channel Impulse Response (CIR) resulting in significant performance degradation that is reduced by adding a pulse train to the transmitted data symbols and estimating the CIR by averaging the symbols as they vary from one OFDM symbol to another within the physical data frame (or packet).

Abstract: An error correction codeword. In one embodiment, an irregularly structured LDPC code ensemble possessing strong overall error performance and attractive storage requirements for a large set of codeword lengths. Embodiments of the invention can offer communication systems with better performance and lower terminal costs due to possible reductions in mandatory non-volatile memory over conventional systems.

Abstract: A low density parity check code is generated by defining first a framework combining symbol detection and low density parity check decoding. Probabilistic information describing multiple-input-multiple-output channels is defined, and a low density parity check code is generated based on said framework and said probabilistic information describing multiple-input-multiple-output channels.

Abstract: Apparatus, and an associated method, for facilitating optimization of the communication capacity of a communication system. A selector is coupled to receive channel state information associated with the channel conditions upon subcarriers defined pursuant to an OFDM (orthogonal frequency division multiplexing) the selector operates to select communication allocation of the data to be communicated on the different ones of the subcarriers. Selection is made pursuant to a selected optimization scheme. And, bit and power profiles are formed that are utilized to control the modulation scheme by which data is modulated upon the different subcarriers. As channel conditions change, the communication allocations are adaptively altered.

Abstract: Methods, apparatus and computer program products are provided for encoding and/or decoding a data block. The method for encoding a data block includes the steps of: providing an information block of size k, I=(i0,i1, . . . i(k?1); and encoding the information block into a low-density parity-check (LDPC) codeword c of size n, c=(i0, i1, . . . i(k?1), p0, p1, . . . , p(n?k?1)), by adding n?k parity bits obtained so that H·cT=0, where H is an (n?k)×n parity-check matrix.

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: 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 and encoded 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 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.

Abstract: A transmitter determines a number of available bits (Navbits) in a minimum number of orthogonal frequency division multiplex (OFDM) symbols in which a data field of a packet may fit, by Navbits=(NCBPS*(1+USTBC))*ceil(Npld/(NCBPS*R*(1+USTBC))), where USTBC equals 1 when Space-Time Block Code (STBC) is used and 0 otherwise, where Npld=LENGTH*8+16, where NCBPS is the number of coded bits per symbol, where R is the code rate, and where LENGTH is a number of bytes in a Physical Layer Convergence Protocol (PLCP) PLCP Service Data Unit (PSDU); and determines an integer number of Low-Density Parity-Check Code (LDPCC) codewords to be transmitted, NCW, and the length of the codewords to be used, LLDPC, from information capable of being expressed in a table format.

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.