Patent ID: 8160166
Filing Date: 2012-04-17
Classification: H04B,H04L

Abstract:
1. A communications device, comprising: a demapping and demodulation circuit for processing an OFDM communications signal that had been transmitted along a communications channel, wherein the OFDM communications signal comprises modulated subcarriers carrying communications data forming a data payload and modulated subcarriers carrying a training sequence forming a preamble, wherein the OFDM subcarriers carrying the training sequence are selectively turned ON and OFF pseudo-randomly and have an applied quadratic phase modulation and have a sample for each subcarrier at a center of a frequency bin using evenly spaced, equal amplitude subcarriers that have a set phase of each sinusoid to a specific angle with the quadratic phase modulation to form a low peak-to-average power ratio (PAPR) preamble; and a channel estimate circuit operative for measuring fluctuations within a flat-topped spectrum of the received OFDM communications signal corresponding to the preamble to reflect the frequency response of the communications channel.