Stewart N Crozier, Age 681247 Mallard Ct, Boulder, CO 80303

6339834, Jan 15, 2002

May 27, 1999

09/320934

Stewart N. Crozier - Groton MA
Andrew Hunt - Ottawa, CA
John Lodge - Kanata, CA
Paul Guinand - Fitzroy Harbour, CA

Her Majesty the Queen in right of Canada, as represented by the Minister of Industry through the Communication Research Centre - Ottawa

H03M 1327

714701

Interleavers based on golden-section increments are disclosed for use with Turbo and Turbo-like error-correcting codes. The interleavers have a tendency to maximally spread the error-bursts generated by an error-burst channel or decoder, independent of the error-burst length. The code block size uniquely defines a golden section increment without having to perform a time consuming search for the best increment value. The disclosed embodiments include golden relative prime interleavers, golden vector interleavers and dithered golden vector interleavers. Also disclosed are methods to reduce the size of memory required for storing the interleaving indexes.

6460161, Oct 1, 2002

Jun 1, 1999

09/324428

Stewart N. Crozier - Groton MA
Andrew Hunt - Ottawa, CA

Her Majesty the Queen in right of Canada, as represented by the Minister of Industry through the Communications Research Centre

H03M 1341

714795

A simplified method of history handling for the Viterbi decoding of convolutional codes is described herein. The state number, or one or more of the most-significant bits of the state number, is loaded into the corresponding state history. Each state number represents the sequence of data bits that, in convolutional encoding, would give rise to the corresponding state. The most recent data bit provides the least significant bit of the state number. This invention reduces the processing requirements associated with the handling of the history, and is especially useful for decoder implementations using general-purpose processors.

6510536, Jan 21, 2003

Jun 1, 1999

09/324429

Stewart N. Crozier - Groton MA
Ken Gracie - Ottawa, CA
Andrew Hunt - Ottawa, CA
John Lodge - Kanata, CA
Paul Guinand - Fitzroy Harbour, CA

Her Majesty the Queen in right of Canada, as represented by the Minister of Industry through the Communications Research Centre

H03M 1341

714755, 714794, 714795

Methods of reduced-complexity max-log-APP processing are disclosed for use with Turbo and Turbo-like decoders. The invented methods of decoding are derived from max-log-APP processing and significantly lower the processing required for decoding convolutional codes by eliminating a portion of the calculations conventionally associated with max-log-APP processing. The disclosed embodiments provide simplified methods of metric combining based on determining the bits of an MLSE sequence with different alternative approaches. Also disclosed is an early stopping method that uses the reduced-complexity max-log-APP decoder to reduce the average number of decoding operations required by an iterative Turbo decoder.

6530059, Mar 4, 2003

Jun 1, 1999

09/324812

Stewart N. Crozier - Groton MA
Andrew Hunt - Ottawa, CA
John Lodge - Kanats, CA
Paul Guinand - Fitzroy Harbour, CA

Her Majesty the Queen in right of Canada, as represented by the Minister of Industry Through the Communication Research Centre

H03M 1303

714786

A method of creating tail-biting recursive systematic convolutional and turbo codes, and the associated encoders, are described herein. According to the method, symbols from the set of data to be transmitted are used to preset the starting state of the encoder, and are replaced in a systematic set by an equivalent number of tail-biting symbols that force the ending state of the encoder to be the same as the starting state. The presetting of the starting state allows for simpler calculations in choosing the tail-biting symbols, and allows a message to be transmitted with a reduced number of symbols The reduction in the number of symbols used for overhead in this invention provides an increase in the data transmission rate.

6693983, Feb 17, 2004

Oct 5, 1999

09/412229

Michael L. Moher - Ottawa, CA
Stewart N. Crozier - Groton MA
Paul Guinand - Fitzroy Harbour, CA

Her Majesty the Queen in right of Canada, as represented by the Minister of Industry through the Communication Research Centre - Ottawa

H04L 2706

375341, 375340, 375344, 375365

Digital signals transmitted on an RF carrier modulated in phase and amplitude and subject to noise constitute separate bursts each comprising information symbols of data and a pair of separated unique words. The signals are subjected to processing which involves reception of the signals and an initial conversion to approximate baseband and then analog to digital sampling. Quadrature and in phase samples are then stored in a buffer. The buffered samples are subjected to coarse timing, coarse frequency synchronization, a first phase correction, fine timing, further phase and amplitude correction and finally to fine frequency correction and subsequent reliability estimation.

6728927, Apr 27, 2004

May 25, 2001

09/864396

Stewart N. Crozier - Groton MA

Her Majesty the Queen in Right of Canada, as represented by the Minister of Industry through the Communications Research Centre - Ontario

H03M 1303

714790, 714787

A system and method are provided for designing high-spread, high-distance interleavers for turbo-codes. The first approach is called high-spread random interleaving, and is based on a new and more effective definition of interleaver spread. The second approach is called dithered-diagonal interleaving. Both methods can be used to design interleaves of arbitrary length. The second approach can actually achieve the theoretical maximum spread for many specific block sizes, and at the same time include significant dither for the elimination of low-weight codewords. Both design methods are easy to implement and require very little processing. Also provided is a method for modifying any interleaver to improve the distance spectrum for a specific turbo-code. It is shown that, for a block size of only 512 data bits and for a code rate of , the flares in the packet error rate (PER) and bit error rate (BER) curves can be kept below 10 and 10 , respectively.

6857087, Feb 15, 2005

Jun 7, 2002

10/165122

Stewart N. Crozier - Groton MA, US
Paul Guinand - Fitzroy Harbour, CA

Her Majesty the Queen in right of Canada, as represented by the Secretary of State for Industry through the Communication Research Centre

G06F029/00
H03M013/00

714702, 714756

An interleaver for interleaving a set of K ordered elements is disclosed herein. The disclosed interleaver can be expressed as a single permutation that corresponds to two local dithering operations and a global permutation operation. The single permutation can be represented as a small collection of short vectors, and can be calculated recursively, allowing the interleaver to be both stored and implemented using a smaller amount of memory than conventionally possible.

7827472, Nov 2, 2010

May 25, 2007

11/753924

Stewart N. Crozier - Boulder CO, US
Kenneth Gracie - Ottawa, CA
Ron Kerr - Kanata, CA

Her Majesty the Queen in right of Canada, as represented by the Minister of Industry, through the Communications Research Centre Canada - Ottawa, Ontario

H03M 13/03
G06F 11/00

714790, 714787, 714788, 714701

The invention relates to an encoding system and method for generating concatenated codes which utilize interleaving and data puncturing. The method includes selecting first and second puncture location sets defining desired puncture locations in non-interleaved and interleaved data sequences, respectively. A puncture-constrained interleaver is provided, which permutes the first puncture location set into the second puncture location set, so as to provide desired regular puncture patterns for all constituent codes. In a preferred embodiment, the puncture-constrained interleaving alters a symbol location relative to a puncture mask so as to satisfy a pre-defined spread or distance constraint.