Patent ID: 7394865
Filing Date: 2008-07-01
Classification: H04L

Abstract:
1. A communication unit comprising: a storage medium for storing a signal constellation, the signal constellation comprising: a plurality of constellation points wherein two constellation points defining a minimum separation from one another are separated by a distance D based on a maximized minimum difference between conditional probability distributions; and at least one of a transmitter or a receiver, wherein the transmitter comprises a mapper for converting an input signal to a plurality of data symbols that each correspond to at least one of the constellation points, a pilot circuit for adding pilot symbols to the data symbols, and a modulator for modulating the data symbols in accordance with a multi-carrier transmission technique, and wherein the receiver comprises a channel estimator for estimating a channel of a multi-carrier system using pilot symbols of a received set of symbols, a demodulator for demodulating at least a portion of the received set of symbols in accordance with a multi-carrier transmission technique, and a de-mapper for converting the demodulated symbols to a plurality of data signals that each alone or in combination correspond to a constellation point; wherein the distance D is the maximized minimum difference, given by: wherein i and j are integer indexes, C is the signal constellation, c