Digital communication system having a punctured convolutional coding system and method

A digital communication system, comprising:

• a. a transmitter for convolutionally coding a digital input to produce a convolutional coded output, and for puncturing the convolutional coded output to generate a punctured output and for transmitting the punctured output using a modulated signal, including:
• i) a convolutional coding circuit of code rate k/n for receiving the digital input and defining input k-tuples of k-bits, and for outputting for each k-tuple a corresponding n-tuple of n-bits where the n-tuples form a convolutional coded output;
• ii) a puncturing circuit for receiving the convolutional coded output and for puncturing the convolutional coded output on a block-by-block basis so as to output a punctured output at a punctured code rate of z/q, where z=.gamma.k, the puncturing circuit including:
• a) a transmission mask circuit for grouping the convolutional coded output into puncturing blocks as the convolutional coded output passes through the puncturing circuit, and for puncturing each puncturing block according to a deleting pattern having transmission and nontransmission bits,
• b) a deleting pattern memory for storing the deleting pattern, and
• c) wherein the deleting pattern and each puncturing block has a bit length equal to p.gamma.n, where p is an integer .gtoreq.2;
• and
• b. a receiver for receiving the modulated signal and decoding the modulated signal to output a decoded output corresponding to the digital input, the receiver including:
• i) a demodulator for receiving the modulated signal and demodulating the modulated signal so as to output a punctured coded output, and
• ii) a decoder for receiving the punctured coded output and for decoding the punctured coded output so as to output a decoded output.

A punctured convolutional coding method for a digital communication system, comprising the steps of:

• a. convolutionally coding a digital input with a convolutional coding circuit of code rate k/n to produce a convolutional coded output, the convolutionally coding step including:
• i) inputting the digital input into the convolutional coding circuit and defining input k-tuples of k-bits, and
• ii) outputting for each k-tuple a corresponding n-tuple of n-bits where the n-tuples form a convolutional coded output;
• b. puncturing the convolutional coded output with a puncturing circuit to generate a punctured output of rate z/q, where z=.gamma.k, for transmission, the puncturing step including:
• i) inputting the convolutional coded output into a transmission mask circuit,
• ii) grouping the convolutional coded output into puncturing blocks as the convolutional coded output passes through the transmission mask circuit, and
• iii) puncturing each puncturing block according to a deleting pattern having transmission and nontransmission bits,
• iv) storing the deleting pattern in a deleting pattern memory, and v) wherein the deleting pattern and each puncturing block have a bit length equal to p.gamma.n, where p is an integer .gtoreq.2.