Abstract: A transmitter for a communications network, the transmitter comprising: receiving means for receiving data; accessing means for accessing a parity check code; generating means for generating encoded data including an error correction codeword using the data and the parity check code; and transmitting means for transmitting the encoded data and the error correction codeword, wherein the parity check code comprises a parity check matrix which, in expanded form, can be represented by the matrix H having the general structure ( A B T C D E ) ? ` wherein A, B, T, C, D and E represent sub-matrices, ET?1B being equal to the null matrix, the generating means comprising summing circuitry arranged to receive matrix elements ET?1A and C to generate a sum, and matrix multiplication circuitry for receiving the sum, a matrix element D?1 and a matrix sT comprising the data, the matrix multiplication circuitry being operable to generate a parity part p1T of the error correction codeword according

Abstract: An error correction decoder for block serial pipelined layered decoding of block codes includes primary and mirror memories that are each capable of storing log-likelihood ratios (LLRs) for one or more iterations of an iterative decoding technique. The decoder also includes a plurality of elements capable of processing, for one or more iterations, one or more layers of a parity-check matrix. The elements include an iterative decoder element capable of calculating, for one or more iterations or layers, a LLR adjustment based upon the LLR for a previous iteration/layer, the LLR for the previous iteration/layer being read from the primary memory. The decoder further includes a summation element capable of reading the LLR for the previous iteration/layer from the mirror memory, and calculating the LLR for the iteration/layer based upon the LLR adjustment for the iteration/layer and the previous iteration/layer LLR for the previous iteration/layer.

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: 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: In one aspect thereof this invention provides a method to increase data throughput in an Orthogonal Frequency Division Multiplex (OFDM) wireless communications system. The method includes modeling data throughput as a function of received Signal to Noise Ratio (SNR) with a sigmoid function to produce a throughput curve characterized as having a lower knee region and an upper knee region; and performing a gradient ascent search along the throughput curve by varying the power of a plurality of sub-carriers so as to remove power from any sub-carrier having a received SNR to the left of the lower knee region, and to re-allocate the removed power to sub-carriers having a received SNR to the right of the lower knee region.

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: 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: 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: 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: Apparatus, and an associated method, for allocating communication data for communication in a multi-channel communication system, such as an OFDM system. An adaptive bit, power, and code rate scheme for a sending station that utilizes LDPC codes selects together bit, power, and code rates of data that are to be communicated upon different ones of the channels in manners that optimize a selected performance criteria.

Abstract: In a multi-user frequency domain spreading downlink MC-CDMA system. a group of sub-carriers can be replaced by an equivalent sub-carrier of a conventional OFDM modem for purposes of resource allocation to improve the system performance. The chips for a given user are spread only within the group. Confinement insures synchronization between different users' chips that is essential to the recovering and separation of user symbols at the receiver. There is no limit imposed on the group size, which permits different spreading code lengths to be used for different scenarios or for performance tuning.

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.

Abstract: Disclosed is a method to operate an orthogonal frequency duplex multiplexing (OFDM) communications system, and an OFDM system that operates in accordance with the method. The method includes, when transmitting data over a plurality of OFDM sub-channels from an OFDM transmitter (12A) to an OFDM receiver (12B) through a channel (24), operating an adaptive learning automaton (50) to adjust values of modulation coding scheme (MCS) switching thresholds so as to maximize at least one selected performance criterion; based on the values of the switching thresholds, selecting a MCS and modulating data with the selected MCS and transmitting the modulated data over at least some of the sub-channels. The method further includes receiving the data at the OFDM receiver and demodulating the received data using a demodulator that corresponds to the selected MCS.

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.