Conexant Systems, Inc.

Rockwell Science Center, Inc.

Ramin A Nobakht

Sverrir Olafsson

Olafur Orn Jonsson

Sandeep Rajpal

A method is disclosed for encoding and modulating bits of an information stream and transmitting them over a designated channel in a high speed communication system. The method includes the steps of dividing a set of the entire constellation of available points into a finite plurality of zero parity vectors defined by two criteria, namely that (1) the column vectors have odd parity and (2) a group of a predefined integer number of column vectors have a 0 modulus (i.e. be divisible by a given number). Column vectors forming only a partially dimensioned portion of the code (e.g. 4D) corresponding to one discrete baud interval are preferably transmitted in a systematic form and with sufficient coding gain for adaptive DFE equalization and whereby a group of column vectors corresponding to an integer number of successive baud intervals that form the fully dimensioned code (e.g. 16D) are transmitted with correlation to one another to achieve an even greater amount of coding gain suitable for high reliability data transmission with error correction and subsequent detection that yield a low bit error rate.

4 x 4 dimensional block modulation code for a PAM-5 constellation

A multi-dimensional equalizer/decoder is disclosed for equalizing a channel transmitting electrical pulses corresponding to a plurality of interdependent symbols formed according to the rules of a multi-dimensional code (e.g. block lattice coded modulation). The symbols are received by the equalizer/decoder over multiple symbol (baud) periods because it takes more than one symbol period to receive a minimum decodable number of symbols on the given number of physical channels. The equalizer/decoder employs a preliminary and a final decision device which cooperate with the components of an 'equalization layer.' A plurality of equalization layers may be used if the symbols are received over a plurality of physical channels. Each equalization layer has first, second, and third, adaptive, feed forward filters, along with appropriately located buffers for collecting decodable groups of the transmitted symbols for group-by-group provision to the decision devices. The equalizer/decoder beneficially permits equalization of a channel used to transmit a multi-dimensional code block, for example, without requiring that a decodable number of symbols arrive in a single symbol interval. Accordingly, a communication system incorporating the equalizer/decoder may implement a high order, multidimensional code that provides enhanced coding gain even where the number of symbols in the code is so large that, given the physical channels available, it must be transmitted over multiple symbol periods. Where the code permits, the equalizer/decoder may make preliminary decisions regarding a reduced number of symbols while continuing to make final decisions using the maximum number of symbols to achieve maximum code gain.

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Laguna Niguel, CA, United States of America

Ramin A Nobakht