US 5,910,967 A · Pragmatic encoder and method therefor

Abstract

A communication system (11) uses concatenated coding in which an inner code is configured to match the needs of an outer code. The inner code is implemented through a pragmatic trellis coded modulation encoder (18) and decoder (34). A parser (50) of the encoder (18) distributes fewer than one user information bit per unit interval (66) to a convolutional encoder (58) which generates at least two convolutionally encoded bits for each user information bit it processes. Exactly one of the convolutionally encoded bits is phase mapped (56) with at least two user information bits during each unit interval (66). The decoder (34) detects a frame sync pattern (48) inserted into the user information bits to resolve phase ambiguities. Phase estimates are convolutionally decoded (100) to provide decoded data estimates that are then used to selectively rotate the phase estimates prior to routing the phase estimates to a slice detector (118).

Claims15

Dependent claims

An apparatus for pragmatically encoding information bits to be communicated at a rate of three or more bits per unit interval, said apparatus comprising:

a parsing circuit for distributing said information bits;
a convolutional encoder coupled to said parsing circuit, said convolutional encoder being configured to produce at least two convolutionally encoded bits for each information bit processed through said convolutional encoder;
a phase mapping circuit coupled to said parsing circuit, said phase mapping circuit being configured to receive at least two of said information bits from said parsing circuit per unit interval;
and
a multiplexing circuit, coupled between said convolutional encoder and said phase mapping circuit, said multiplexing circuit being configured to route no more than one of said convolutionally encoded bits produced for each information bit received by said convolutional encoder to said phase mapping circuit per unit interval.

2 more elements

A pragmatic encoding method for coding information bits to be digitally communicated at a rate of three or more bits per unit interval, said method comprising the steps of:

distributing a first portion of said information bits to a phase mapping circuit and a second portion of said information bits to a convolutional encoder, said first portion comprising at least two bits per unit interval and said second portion comprising less than one bit per unit interval;
convolutionally encoding said second portion of said information bits so that at least one convolutionally encoded bit is produced per unit interval;
and
phase mapping said first portion of said information bits and said convolutionally encoded bits so that no more than one convolutionally encoded bit is mapped per unit interval.

1 more element

Dependencies are inferred from the claim text.

Pragmatic encoder and method therefor

Life of this patent

Pragmatic encoder and method therefor

Life of this patent

Abstract

Claims15