Fast Constant Weight Codeword to Index Converter
Abstract
Constant weight codewords, in which the number of 1's is fixed, are essential to many coding applications. In this paper, we show an efficient circuit that converts a constant weight codeword into a unique index of that codeword. For example, this circuit is necessary when constant weight codewords are used to transmit data on and off chip. Our circuit is based on the combinatorial number system in which the digits are binomial coefficients. It has O(n3) area complexity and O(n) delay, where n is the number of variables. Two types of circuits are proposed. Various constant weight codes are implemented on an FPGA, including a 64-out-of-128 code. These implementations support our complexity analysis.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2011
- Accession Number
- ADA547556
Entities
People
- J. T. Butler
- T. Sasao
Organizations
- Naval Postgraduate School