US Patent 7600164 Interleaving/de-interleaving using compressed bit-mapping sequences

A method of mapping input bit positions in an input sequence to output bit positions in an output sequence uses compressed mapping sequences stored in memory derived from a predetermined mapping function. The mapping function is decompressed into periodic component functions that are used to generate the compressed mapping sequences. Each compressed mapping sequence comprises a plurality of partial mapping values that represent one period of a corresponding component function or group of component functions. Partial mapping values are selected from each compressed mapping sequence based on a bit index of the current input bit and summed or otherwise combined to get an output index.