Variable Span Fibonacci Modulation Codes with Limited Byte Error Propagation

We present techniques for reducing error propagation in modulation encoded data. Error propagation is reduced by using Fibonacci modulation codes that have limited span at certain positions. Errors occurring in bit positions of an encoded sequence that correspond to the limited span elements do not propagate beyond the span of those elements in the decoded sequence. Simulation results show that the proposed variable span modulation codes yield improved sector error rates when used instead of fixed span codes in magnetic recording systems.