Patent ID: 6711120
Filing Date: 2004-03-23
Classification: H04L

Abstract:
A method for operating a cellular orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access wireless system in which each base station establishes its own tone set within the same frequency band, comprising the steps of:in a first base station corresponding to a first cell, assigning a first set of orthogonal tones, said first set of orthogonal tones being for use in communicating between said first base station and mobile units served by said first base station; and in a second base station corresponding to a second cell, located adjacent said first cell, assigning a second set of orthogonal tones, said second set of orthogonal tones being for use in communicating between said second base station and mobile units served by said second base station; wherein said second set of orthogonal tones are placed within the same frequency band as are said first set of orthogonal tones, tones in said second set of orthogonal tones being positioned in said same frequency band at the same points but being offset by a fixed frequency offset which is smaller than the frequency separation between adjacent tones in said first set of orthogonal tones.