Patent ID: 8189697

Claim:
A communications device, comprising: a demapping and demodulation circuit as a Fast Fourier Transform (FFT) circuit and subcarrier demapper 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 that includes a long sync sequence for acquisition, detection, frequency and channel estimation and having a extended guard interval (GI), wherein the OFDM subcarriers carrying the training sequence are selectively turned ON and OFF pseudo-randomly and have an applied quadratic modulation to produce a low peak-to-average power ratio (PAPR) preamble; and a channel estimate circuit positioned to receive signals after processing within said FFT circuit and subcarrier demapper circuit, wherein said channel estimate circuit is operative with said FFT and subcarrier demapper circuit for estimating channel characteristics of the communications channel based on splitting the extended guard interval from the long sync sequence and processing into values that represent the inverse low PAPR preamble as plus or minus one (+/−1) values in a real or imaginary component as adds and subtracts.