Reduced latency interleaver utilizing shortened first codeword
First Claim
Patent Images
1. A method of interleaving a stream of codewords, each codeword having a length L symbols, said method comprising the steps of:
- interleaving the last L-U symbols of a first codeword with the first L-U symbols of a second codeword;
interleaving the first U symbols of a third codeword with the last U symbols of said second codeword;
shortening the initial first codeword received in said stream of codewords by skipping over the first U symbols of said initial first codeword; and
wherein L and U are positive integers.
2 Assignments
0 Petitions
Accused Products
Abstract
A interleaver/de-interleaver mechanism for reducing the latency of transmitted interleaved codewords. The interleaver/de-interleaver mechanism utilizes a shortened first codeword which functions to offset the interleaving and transmission on subsequent codewords so as to achieve reduced latency depending on the degree of shortening applied. The interleaver/de-interleaver mechanism is particularly useful in power line carrier based systems to reduce the exposure to burst errors by providing interleaving with minimal latency penalty.
-
Citations
44 Claims
-
1. A method of interleaving a stream of codewords, each codeword having a length L symbols, said method comprising the steps of:
-
interleaving the last L-U symbols of a first codeword with the first L-U symbols of a second codeword;
interleaving the first U symbols of a third codeword with the last U symbols of said second codeword;
shortening the initial first codeword received in said stream of codewords by skipping over the first U symbols of said initial first codeword; and
wherein L and U are positive integers. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. 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. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. 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. - View Dependent Claims (19, 20, 21, 22, 23, 24)
-
-
25. 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. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33)
-
-
34. 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. - View Dependent Claims (35, 36)
-
-
37. 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. - View Dependent Claims (38, 39, 40, 41, 42, 43, 44)
-
Specification