Qualcomm Incorporated

University of California

Jack K Wolf

Ephraim Zehavi

Joseph P Odenwalder

Chong U Lee

Rajiv Vijayan

Brian K Butler

Yongbin Wei

Nagabhushana T Sindhushayana

Alexander Vardy

Paul Siegel

Eitan Yaakobi

Edward George Tiedemann, Jr

Tao Chen

Paul E Bender

Ramin Rezaiifar

Leonid Sheynblat

Roberto Padovani

Dexter Tamio Chun

Jungwon Suh

Klein S Gilhousen

Tirdad Sowlati

Dung Ngoc Doan

Franklin Peter Antonio

Leonard N Schiff

Alejandro Raul Holcman

Samir Khalil Khazaka

Scott Kayser

Arik Mimran

Daniel Ray Kindred

Edward G Tiedemann

Ryan Milne

The invention provides a family of 2-write WOM-codes, preferred embodiments of which provide improved WOM-rates. Embodiments of the invention provide constructs for linear codes C having a 2-write WOM-code. Embodiments of the invention provide 2-write WOM-codes that improve the best known WOM-rates known to the present inventors at the time of filing with two writes. Preferred WOM-codes are proved to be capacity achieving when the parity check matrix of the linear code C is chosen uniformly at random. Preferred embodiments of the invention provide an electronic device utilizing an efficient coding scheme of WOM-codes with two write capability. The coding method is based on linear binary codes and allows the electronic device to write information to the memory twice before erasing it. This method can be applied for any kind of memory systems, and in particular for flash memories. The method is shown to outperform all well-known codes.

Efficient two write WOM codes, coding methods and devices

The invention provides WOM coding methods and electronic devices with error correcting codes that provide single, double and triple error correction. In one coding, if the code corrects two/three errors, it has two/three parts of redundancy bits. For double error correction, if only one part of the redundancy bit has no errors then it is possible to correct one error. For triple error correction, if only one/two parts of the redundancy bits have no errors then it is possible to correct one/two errors. Codes that correct/detect a single, two and three cell-erasures are provided. A code that has three roots, &#x3b1;, &#x3b1;, &#x3b1;, each of which is a primitive element and where every pair of roots generates a double error correcting code, is provided. Codes and coding utilizing a triple error correcting WOM code that can correct an arbitrary number of errors are provided.

Strong single and multiple error correcting WOM codes, coding methods and devices

A method and apparatus for multicasting of a multi-packet message are disclosed. Data to be transmitted as a message are divided into N sets, each set being encoded to generate encoded data. A set of parity bits is separated from each of the N sets of encoded data. The N sets of separated parity bits are encoded by a systematic code with a predetermined distance S across the N sets, resulting in N' parity-bit packets. The N&#x2032; parity-bit packets are encoded with a code that is selected so that each receiving station decodes the N&#x2032; parity-bit packets with a high probability. The N-packet message, comprising the N sets of encoded data less the separated bits, and the N&#x2032; packets are multicasted. If less than S packets of the N-packet message fail to decode at a receiving station, the receiving station recovers all N packets using the N&#x2032; packets.

Method and an apparatus for use of codes in multicast transmission

A system involves a first SerDes link from a first integrated circuit (IC) to a second IC and a second link from the second IC to the first IC. Power consumption settings in circuitry of the first link are adjusted to control power consumption such that the bit error rate of the first link is maintained in a range, where the lower bound of the range is substantially greater than zero. Power consumption settings in circuitry for the second link are adjusted to control power consumption such that the bit error rate of the second link is maintained in range, where the lower bound of the range is substantially greater than zero. In one example, circuitry in the second IC detects errors in the first link and reports back via the second link. The first IC uses the reported information to determine a bit error rate for the first link.

SerDes power throttling as a function of detected error rate

Methods and apparatuses for enhanced processing of received channels in a mobile communications system is described. Particularly, convolutionally encoded tail biting data in a mobile communications system is efficiently decoding by replicating the received encoded signal N times, where N equals a number of iterations. A Viterbi decoding algorithm is applied and a most likely survivor path is obtained. The ensuing decoding window is set as a fixed decoding window and placed at a mid-section of the most likely survivor path. Simulations have shown codeword accuracy to be comparable to MLSE with less complexity. A high degree of accuracy has been obtained for N=3.

Tail-biting convolutional decoding

Operating a communication device in a half-duplex mode using only overhead channels; and substantially free running a timing reference obtained during reception to allow a timing reference value to drift during transmission.

Low duty cycle half-duplex mode operation with communication device

A Method and System for Utilization of an Outer Decoder in a Broadcast Services Communication System is described. An outer decoder and an inner decoder encode a block of information to be transmitted, to improve protection by adding redundancy. The redundancy permits decoding of the information from less than a complete encoded block of information. Consequently, the receiving station determines when sufficient amount of information for successful decoding has been received, and utilizes the time remaining before the next block of information arrives to perform other activities, e.g., hard handoff on a broadcast channel, inter-frequency hard handoff, and other activities. Alternatively, the receiving station can cease reception, thus decrease power consumption. Furthermore, part of the information block may be utilized for transmission of signaling information.

Method and system for utilization of an outer decoder in a broadcast services communication system

In a communication systema method and apparatus provide for decoding a sequence of turbo encoded data symbols. The channel nodes R, Rand Rare updated based on a received channel output, and the outgoing messages from symbol nodes () are initialized. The symbol nodes symbol nodes () are in communication with the channel nodes R, Rand R. Updates of computational nodes C () and D () at different time instances are performed in accordance with a triggering schedule.

Turbo decoding method and apparatus for wireless communications

Techniques for efficiently performing erasure-and-single-error correction block decoding on a received block of symbols previously coded column-wise with an (N, K) linear block code and row-wise with an error detection code (e.g., a CRC code). Initially, each row of the received block is marked as either an erased row or an un-erased row. To perform erasure-and-single-error correction block decoding on the received block, a codeword corresponding to a column of the received block containing an undetected symbol error is initially identified. The location of the symbol error in the codeword is then determined based on a particular block decoding scheme and corresponding to the selected (N, K) block code. The row of the received block containing the symbol error is then marked as an erased row. Block decoding may then be performed for the received block with the newly marked erased row containing the symbol error.

Erasure-and-single-error correction decoder for linear block codes

A decoding method and apparatus include providing capability for decoding data symbols that were encoded in a transmitter by either a serial-concatenated code or turbo code in a parallel processing fashion. The receiver upon knowing the encoding method may reconfigure the selection of data symbols from a table to accommodate the appropriate decoding process. Initially a data symbol estimate for a number of data symbols of a plurality of data symbols Xi, Yi, and Wi are determined. The estimates of data symbols Xi, Yi, and Wi passing to a first and second decision nodes include estimates for the variables in one or more encoding equations. A new estimate for the data symbol Xi is determined based on the estimate determined at the initial step and the new estimate for each occurrence of the data symbol Xi at the first and second decision nodes. After normalizing estimates of data symbols Xi, Yi, and Wi, a new estimate for data symbol Xi may be determined which holds more confidently a true value for the data symbol Xi than a previously determined estimate.

Decoding method and apparatus

In an orthogonal frequency division multiplexing (OFDM) system which uses an outer Reed-Solomon encoder and interleaver an inner convolutional encoder, after the inner convolutional encoding the data bits are interleaved, and then grouped into symbols, each symbol having &ldquo;m&rdquo; bits. After grouping, the symbols are mapped to a complex plane using quadrature amplitude modulation (QAM). Thus, bits, not symbols, are interleaved by the inner interleaver. A receiver performs a soft decision regarding the value of each bit in each complex QAM symbol received.

Bit interleaving for orthogonal frequency division multiplexing in the transmission of digital signals

A decoding method and apparatus include providing capability for decoding data symbols that were encoded in a transmitter by either a serial-concatenated code or turbo code in a parallel processing fashion. The receiver upon knowing the encoding method may reconfigure the selection of data symbols from a table ( ) to accommodate the appropriate decoding process. Initially a data symbol estimate for a number of data symbols of a plurality of data symbols Xi, Yi, and Wi are determined. The estimates of data symbols Xi, Yi, and Wi passing to a first and second decision nodes ( ) include estimates for the variables in one or more encoding equations. A new estimate for the data symbol Xi is determined based on the estimate determined at the initial step and the new estimate for each occurrence of the data symbol Xi at the first and second decision nodes ( ). After normalizing estimates of data symbols Xi, Yi, and Wi, a new estimate for data symbol Xi may be determined which holds more confidently a true value for the data symbol Xi than a previously determined estimate.

In an orthogonal frequency division multiplexing (OFDM) system which uses an outer Reed-Solomon encoder and interleaver an inner convolutional encoder, after the inner convolutional encoding the data bits are interleaved, and then grouped into symbols, each symbol having 'm' bits. After grouping, the symbols are mapped to a complex plane using quadrature amplitude modulation (QAM). Thus, bits, not symbols, are interleaved by the inner interleaver. A receiver performs a soft decision regarding the value of each bit in each complex QAM symbol received.

Bit interleaving for orthogonal frequency division multiplexing in the

A method and apparatus for encoding and decoding QAM trellis modulated data. In the transmitter, a subset of bits of an input bit set are convolutionally encoded based upon a punctured convolutional code of a lower data rate to provide a set of coded symbols. The coded symbols and the uncoded bits of the input bit set are provided to a QAM modulator to provide a QAM modulation signal indicative of the values of coded symbols and the uncoded bits. In the receiver a QAM demodulator converts the received QAM signal to QAM signal space coordinates. A decoder employing the Viterbi algorithm is used to reconstruct a corrected estimate of the values of the coded data bits from the received signal coordinates. The corrected estimate of the values of the coded data bits are then used in conjunction with the received signal coordinates to provide corrected estimates of the values of the uncoded input bits.

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La Jolla, CA, United States of America

Jack K Wolf