Patent ID: 7057534

Claim:
A method of generating an output symbol, wherein the output symbol is selected from an output alphabet and the output symbol is such that an input file, comprising an ordered plurality of input symbols each selected from an input alphabet, is recoverable from a set of such output symbols, the method comprising: calculating, according to a predetermined function, a list AL for each output symbol to be output, wherein AL is an indication of weights W associated input symbols associated with the output symbol to be output, and wherein the weights W are positive integers that vary between at least two values and are greater than one for at least one list; and generating an output symbol value B from a predetermined function of the associated input symbols indicated by AL for each output symbol to be output; wherein the number of possible output symbols to be output is effectively unbounded such that the number of output symbols available given any expected signal to noise ratio can be larger than the number of input symbols in the plurality of input symbols.