Patent ID: 7489755
Filing Date: 2009-02-10
Classification: H04B,H04J,H04L

Abstract:
1. An apparatus comprising: a null generator for generating an output data symbol sequence from an input data symbol sequence, wherein the output data symbol sequence exhibits nulls in a frequency domain at particular frequencies that the input data symbol sequence does not exhibit; a pilot inserter for adding a pilot symbol sequence to the output data symbol sequence to create a combined symbol sequence, wherein the pilot symbol sequence exhibits pilot signals corresponding to the nulls of the output data symbol sequence in the frequency domain, wherein the null generator comprises: a first adder for linearly adding together symbols having the same position in their respective groups to generate a groupof symbols, wherein the groups are subgroups of the input data symbol sequence; a first normalizer for scaling each symbol of the group of symbols by a normalization factor to produce a group of padding symbols used to generate the output data symbol sequence.