Patent ID: 7643535
Filing Date: 2010-01-05
Classification: H04B,H04J

Abstract:
1. A method of processing preambles of signals that are to be transmitted as direct sequence spread spectrum (DSSS) signals and narrowband signals to prepare the preambles for transmission, comprising the steps of: (a) when the signal is to be transmitted as a narrow band signal, providing an unspread preamble that includes a sequence of blocks, with each of the blocks having the same number of code elements in the same predetermined pattern; (b) when the signal is to be transmitted as a DSSS signal, providing a spread preamble that includes a sequence of the same number of blocks as the number of blocks in the unspread preamble, with each of the blocks of the spread preamble having a number of code elements corresponding to a spread-factor multiple of the number of code elements in each of the blocks of the unspread preamble, with each of the blocks of the spread preamble having the same predetermined pattern of code elements; wherein the spread factor is an integer greater than one; (c) providing a preamble encoding sequence that includes the same given number of code elements as the number of blocks of the preamble; and (d) using encoding means to encode the sequence of preamble blocks with sequentially corresponding code elements of the preamble encoding sequence to thereby provide a sequence of encoded preamble blocks.