Patent ID: 6414983
Filing Date: 2002-07-02
Classification: H04B,H04L

Abstract:
An asynchronous digital communication apparatus comprising a frequency hopping (FH) coder,said FH coder comprising: conversion means for converting a data value x which is an element of a Galois field, into a code w which is a non-zero element of said Galois field, according to the following conversion equation using a function f: w=f(x) â€ƒwherein a number M of values which a data can present and a number Q of the elements of said Galois field satisfy: M=2k(k is a positive integer) Q=pr(>M) â€ƒwherein p is a prime number and r is a positive integer; and operation means for calculating, according to said code w, a hopping code vector {circumflex over ( )}y composed of L components using the following Galois operation: {circumflex over ( )}y=wÂ·{circumflex over ( )}&agr;+iÂ·{circumflex over ( )}e â€ƒwherein i is the user identification No. which is an element of said Galois field; &agr; is one of the primitive elements of said Galois field; {circumflex over ( )}&agr; is a spread code vector of L components and is equal to (1, &agr;, &agr;2, . . . &agr;Lâˆ’1) in which L is an integer not less than 2 and not greater than prâˆ’1; and {circumflex over ( )}e is a unit vector of L components and is equal to (1, 1, . . . , 1).