Patent ID: 6868111
Filing Date: 2005-03-15
Classification: H04J

Abstract:
1. A spread spectrum communication system for converting data into a code sequence for facilitating codeword identification by a spread spectrum receiver based only on the received signal and without transmission of a synchronization preamble in addition to the information signal, the system comprising: a) a spread spectrum transmitter for converting information to be transmitted into a stream of digital data, for converting the stream of digital data into a sequence of codewords, the codewords being structured to allow a spread spectrum receiver to identify the codewords when receiver synchronization is lost and restored without using a synchronization preamble, wherein the spread spectrum transmitter divides the stream of digital data into consecutive even and odd tetrad pairs, the codewords are divided into first and second groups, the even tetrad pairs are used to select codewords from the first group and the odd tetrad pairs are used to select codewords from the second group; and b) a spread spectrum receiver for receiving a spread spectrum signal containing the codewords, for identifying codeword boundaries in the received spread spectrum signal based only on the codewords, and for extracting the digital data from the spread spectrum signal.