Techniques for using interleaved encoders to obtain modulation constraints
AssigneeHitachi Global Storage Technologies Netherlands B.V.
InventorsMario Blaum, Ksenija Lakovic, Bruce A. Wilson
Life of this patent
Estimating the term…
Abstract
Techniques are provided for applying modulation constraints to data streams divided into separate interleaved portions. The even and odd bits in a data stream are separated into two data paths. A first modulation encoder encodes the even bits according to a first constraint. A second modulation encoder encodes the odd bits according to a second constraint. The two encoded data streams are then interleaved to form one data stream. The modulation encoders can encode the two data paths using Fibonacci encoding.
Claims16
A disk drive system comprising:
- a demultiplexer that separates even bits and odd bits in the data into two separate data paths;
- a first Fibonacci modulation encoder that encodes the even bits to generate constrained even bits;
- a second Fibonacci modulation encoder that encodes the odd bits to generate constrained odd bits;
- and
- a multiplexer that interleaves the constrained even bits and the constrained odd bits.
A disk drive controller chipset comprising:
- a demultiplexer that separates even bits and odd bits in the data into two separate data paths;
- a first Fibonacci modulation encoder that maps N-bit vectors corresponding to the even bits to a first vector, wherein the first vector has no more than N constrained bits;
- a second Fibonacci modulation encoder that maps N-bit vectors corresponding to the odd bits to a second vector, wherein the second vector has no more than N constrained bits.
A method for applying modulation constraints to data, the method comprising:
- separating even bits and odd bits in a codeword into two data paths;
- applying a first modulation constraint to the even bits to generate constrained even bits using Fibonacci codes;
- applying a second modulation constraint to the odd bits to generate constrained odd bits using Fibonacci codes;
- and
- interleaving the constrained even bits with the constrained odd bits.
Dependencies are inferred from the claim text.