Nokia Corporation

Other

Southern Methodist University

Victor Stolpman

John D Terry

Clive K Tang

Nico Van Waes

Tony R Reid

Pirjo Pasanen

Jae H Son

Jian Zhong Zhang

Olav Tirkkonen

Tejas Maheshbhai Bhatt

Hua Zhang

Dumitru Mihai Ionescu

Juha Heiskala

Jan C Olivier

Amitabh Dixit

Olav Tirkkonnen

Mihai Ionescu

Jerry Don Gibson

Mark Gavin Kokes

Geoffrey Charles Orsak

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=(i, i, . . . i; and encoding the information block into a low-density parity-check (LDPC) codeword c of size n, c=(i, i, . . . i, p, p, . . . , p), by adding n&#x2212;k parity bits obtained so that H&#xb7;c=0, where H is an (n&#x2212;k)&#xd7;n parity-check matrix.

Method, apparatus and computer program product providing for data block encoding and decoding

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.

System and method for precoding in a multiple-input multiple-output (MIMO) system

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.

Apparatus, and associated method, for allocating data for communication upon communication channels in a multiple input communication system

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.

Structured puncturing of irregular low-density parity-check (LDPC) codes

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.

Orthogonal-Frequency-Division-Multiplex-Packet-Aggregation (OFDM-PA) for wireless network systems using error-correcting codes

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.

System and method for adaptive low-density parity-check (LDPC) coding

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.

Method and device for transmission parameter selection in mobile communications

A transmitter determines a number of available bits (N) in a minimum number of orthogonal frequency division multiplex (OFDM) symbols in which a data field of a packet may fit, by N=(N*(1+U))*ceil(N/(N*R*(1+U))), where Uequals 1 when Space-Time Block Code (STBC) is used and 0 otherwise, where N=LENGTH*8+16, where Nis 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, N, and the length of the codewords to be used, L, from information capable of being expressed in a table format.

Apparatus, method and computer program product providing low-density parity-check block length selection

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).

High doppler channel estimation for OFD multiple antenna systems

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.

Irregularly structured, low density parity check codes

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.

Gradient based method and apparatus for OFDM sub-carrier power optimization

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.

Apparatus, and associated method, for facilitating communication allocation in a radio communication system

Puncture sequences S, S, etc. for code rates R, R, etc. less than a maximum code rate Rare defined subsets of a maximum rate puncture sequence Sthat corresponds to the maximum code rate R. Each puncture sequence Sfor a code rate Ris related to the puncture sequence S, of the previous code rate R, and preferably SS. . .SS. 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.

Low-density parity-check codes for multiple code rates

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.

Multiple user adaptive modulation scheme for MC-CDMA

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.

Method and apparatus providing decentralized, goal-orientated adaptive learning in an adaptive orthogonal frequency division multiplex communication system

Growing community of inventors

Dallas, TX, United States of America

Victor Stolpman