Significant improvement in Raptor codes and punctured LDPC codes are
obtainable by use of the invention. In both a transmission scheme for
Raptor-encoded or LDPC-encoded information, a dynamic adjustment approach
is employed. A fraction of a codeword or information frame is
transmitted. A feedback signal is sent from the receiver to the
transmitter indicating either 1) successful decoding, or 2) failure to
decode and/or a feedback signal indicative of a statistical measure of
transmission channel quality. If decoding fails, a further portion of the
codeword or frame is sent. The intensity and/or size of the fraction is
adjusted based on the feedback signal. In one embodiment, a specific
range for probabilities employed in the encoding process for Raptor codes
provides the ability to increase transmission throughput. Further it has
been found that the advantageous Raptor codes are useful in noise
conditions where even the improved punctured LDPC codes of the invention
begin to degrade.