Reduced latency interleaver utilizing shortened first codeword

An interleaver for interleaving a stream of codewords, each codeword having a length L symbols, said method comprising the steps of:

• means for dividing a beginning codeword into a fist portion and a second portion;
• means for dividing an ending codeword into a first portion and a second portion;
• means for interleaving said second part of said beginning codeword and said first part of said ending codeword with one or more intermediate codewords;
• and
• means for skipping the first portion of an initial codeword received in said stream of codewords.

An interleaver for interleaving a stream of codewords, each codeword having a length L symbols, said method comprising the steps of:

• means for interleaving the last L-U symbols of a first codeword with the first L-U symbols of a second codeword;
• means for interleaving the first U symbols of a third codeword with the last U symbols of said second codeword;
• means for shortening the initial first codeword received in said stream of codewords by discarding the first U symbols of said initial first codeword;
• and
• wherein L and U are positive integers.

A method of de-interleaving a stream of symbols, said method comprising the steps of:

• sequentially counting each received symbol;
• upon receipt of the first L symbols, de-interleaving and extracting L-U symbols to construct a first shortened codeword:
• and
• upon receipt of each subsequent L symbols, de-interleaving and extracting L symbols to construct subsequent codewords.

A de-interleaver for de-interleaving a stream of symbols, said method comprising the steps of:

• means for sequentially counting each received symbol;
• means for de-interleaving the first L symbols and for extracting L-U symbols therefrom so as to construct a first shortened codeword;
• and
• means for de-interleaving subsequent groups of L symbols and for extracting L symbols from the previously received group of 2L symbols so as to construct subsequent codewords.

A modem transceiver for transmitting and receiving signals a shared communications media based network, comprising:

• a coupling circuit for generating a receive signal received over said network and for outputting a transmit signal onto said network;
• a transmitter adapted to modulate data to be transmitted in accordance with a modulation scheme so as to generate a transmit waveform therefrom, said transmitter comprising an interleaver for interleaving a stream of codewords, each codeword having a length L symbols, said interleaver comprising:
• means for interleaving the last L-U symbols of a first codeword wit the first L-U symbols of a second codeword;
• means for interleaving the first U symbols of a third codeword with the last U symbols of said second codeword;
• means for shortening the initial first codeword received in said stream of codewords by discarding the first U symbols of said initial first codeword;
• wherein L and U are positive integers;
• a receiver adapted to demodulate said receive signal in accordance with said modulation scheme so as to generate a receive data signal therefrom, said receiver comprising a de-interleaver for de-interleaving a stream of symbols, said de-interleaver comprising:
• means for sequentially counting each received symbol;
• means for de-interleaving the first L symbols and for extracting L-U symbols therefrom so as to constrict a first shortened codeword;
• means for de-interleaving subsequent groups of L symbols and for extracting L symbols from the previously received group of 2L symbols so as to construct subsequent codewords;
• a media access control (MAC) circuit adapted to interface an application processor to said shared communications media;
• said application processor adapted to control the operation of said transmitter, receiver and MAC and to provide an interface between said MAC and an external host.