Punctured convolutional encoder

• US 5,511,082 A
• Filed: 05/10/1994
• Issued: 04/23/1996
• Est. Priority Date: 05/10/1994
• Status: Expired due to Term

• Current Assignee: VIZIO, Inc.
• Original Assignee: General Instrument Corporation (CommScope Holding Company, Inc.)
• Inventors: Heegard, Chris, How, Stephen K.
• Primary Examiner(s): Baker, Stephen M.
• Application Number:
  US08/240,232
• Time in Patent Office: 714 Days
• Field of Search: 371/43
• US Class Current: 714/790
• CPC Class Codes: H03M 13/23 using convolutional codes, e.g. unit memory codes
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0069 Puncturing patterns

Abstract

A method and apparatus are provided for convolutionally encoding digital data with a rate 4/5 convolutional code. A nonoptimal rate 1/2, sixteen-state convolutional code is punctured to rate 4/5 using a puncture map of ##EQU1## and octal generators 25, 37 wherein ν=4. An incoming data stream is processed using the rate 4/5 code. Punctured rate 3/4 and 6/7 codes are also provided.

Claims

1. A method for convolutionally encoding digital data with a rate 4/5 convolutional code, comprising the steps of:

puncturing a rate 1/2, sixteen state convolutional code based on octal generators 25,37 to rate 4/5 using a puncture map of ##EQU14## wherein ν

=4; and

processing an incoming data stream using said rate 4/5 code.

2. A rate 4/5 convolutional encoder comprising:

a rate 1/2, sixteen state convolutional encoder based on octal generators 25,37 coupled to receive an input stream to be encoded; and

means for puncturing the code from said rate 1/2 encoder to rate 4/5 using a puncture map of ##EQU15## wherein ν

=4.

3. A method for convolutionally encoding digital data with a rate 6/7 convolutional code, comprising the steps of:

puncturing a rate 1/2, sixteen state convolutional code based on octal generators 25,37 to rate 6/7 using a puncture map of ##EQU16## wherein ν

=4; and

processing an incoming data stream using said rate 6/7 code.

4. A rate 6/7 convolutional encoder comprising:

a rate 1/2, sixteen state convolutional encoder based on octal generators 25,37 coupled to receive an input stream to be encoded; and

means for puncturing the code from said rate 1/2 encoder to rate 6/7 using a puncture map of ##EQU17## wherein ν

=4.