Variable-Length Constrained Sequence Codes

We outline the construction of simple, high rate constrained sequence codes with variable-length source words and variable-length codewords based on the search of partial extension of a minimal set of codeword lengths. We present optimal word length mappings for a subset of constrained sequence codes, and provide examples of (d, k) and DC-free codes with few codewords and average code rates greater than 99% of capacity.