US 6,307,631 B1 · Pseudorandom bit sequence generator

Abstract

The invention is a method and apparatus for generating a primary pseudorandom bit sequence consisting of a plurality of contiguous P subsequences. Each P subsequence consists of a start sequence of predetermined length followed by a sequence of trailing bits. The method comprises three steps. The first step consists of deriving a feedback bit from each generating sequence in a P subsequence in accordance with a specified rule where a generating sequence is any sequence of contiguous bits in the P subsequence having the same length as the start sequence. The bit that follows a generating sequence is called the trailing bit for that generating sequence. The second step of the method consists of determining a sequence of one or more modifier bits to be used in modifying the P subsequence. The third step of the method consists of modifying the P subsequence utilizing the one or more modifier bits.

Claims44

Dependent claims

A method for generating a primary pseudorandom bit sequence, a primary pseudorandom bit sequence consisting of a plurality of contiguous P subsequences, each P subsequence consisting of a start sequence of predetermined length followed by a sequence of trailing bits, the method comprising the steps:

(a) deriving a feedback bit from each generating sequence in a P subsequence in accordance with a specified rule, a generating sequence being any sequence of contiguous bits in the P subsequence having the same length as the start sequence, the bit that follows a generating sequence being called the trailing bit for that generating sequence;
(b) determining a sequence of one or more modifier bits to be used in modifying the P subsequence;
(c) modifying the P subsequence utilizing the one or more modifier bits.

An apparatus for generating a primary pseudorandom bit sequence, the apparatus comprising:

a primary bit sequence analyzer having access to a primary analysis sequence, a primary analysis sequence being a plurality of the most recent bits from a primary bit sequence, the primary bit sequence comprising a plurality of contiguous P subsequences, each P subsequence beginning with a start sequence, the primary bit sequence analyzer deriving a feedback bit from the primary analysis sequence;
a sequence-modifying unit for supplying the primary bit sequence analyzer with a trailing bit that follows the primary analysis sequence, the trailing bit being either the feedback bit derived by the primary bit sequence analyzer or a modifier bit, the modifier bit being either a predetermined bit stored in the sequence-modifying unit or a bit derived by the sequence-modifying unit.

Dependencies are inferred from the claim text.

Pseudorandom bit sequence generator

Life of this patent

Pseudorandom bit sequence generator

Life of this patent

Abstract

Claims44