Multiplex communications – Generalized orthogonal or special mathematical techniques – Fourier transform
Reexamination Certificate
2003-12-16
2008-11-18
Moe, Aung S. (Department: 2616)
Multiplex communications
Generalized orthogonal or special mathematical techniques
Fourier transform
C370S208000
Reexamination Certificate
active
07453794
ABSTRACT:
A preamble for an OFDM signal synchronizes (104) and estimates (106) the sub-channels with only one code. One polyphase code sequence is used repeatedly for the preamble. The preamble is spread out over the bandwidth, which is the same as an OFDM symbol in the frequency domain and has good autocorrelation characteristics in the time domain. All OFDM signals are added with this preamble at the beginning of the OFDM signal and transmitted on the channel at a transmitter (50). At the receiving end, the receiver (100) first does the autocorrelation process to find out a peak value for synchronization in the time domain. Then, since the polyphase code is known at the receiver, the signal to noise ratio for each sub-carrier is calculated in the frequency domain and smoothed using the normal (Gaussian) distribution to provide the channel estimation. Since the synchronization and channel estimation are processed with a single preamble, the overhead for these two functions is significantly reduced.
REFERENCES:
patent: 6246735 (2001-06-01), Sano et al.
patent: 6658063 (2003-12-01), Mizoguchi et al.
patent: 6934340 (2005-08-01), Dollard
patent: 7085223 (2006-08-01), Izumi
patent: 7218693 (2007-05-01), Troulis
patent: 2002/0172146 (2002-11-01), Wu et al.
patent: 2002/0181389 (2002-12-01), Giannakis et al.
patent: 2002/0181549 (2002-12-01), Linnartz et al.
patent: 2003/0039317 (2003-02-01), Taylor et al.
patent: 2003/0171128 (2003-09-01), Tandai et al.
patent: 2004/0047368 (2004-03-01), Xu
patent: 2004/0131011 (2004-07-01), Sandell et al.
patent: 2004/0141548 (2004-07-01), Shattil
patent: 2004/0184398 (2004-09-01), Walton et al.
patent: 2004/0264362 (2004-12-01), Rhodes
patent: 2005/0073946 (2005-04-01), Dey et al.
patent: 2005/0111590 (2005-05-01), Fang et al.
patent: 2005/0259568 (2005-11-01), Yeh et al.
patent: 2008/0002568 (2008-01-01), Wu et al.
Chu, “Polyphase Codes With Good Periodic Correlation Properties,” IEEE Transactions on Information Theory, 18:531-532, Jul. 1972.
Schroeder, M. “Synthesis of Low-Peak-Factor Signals and Binary Sequences with Low Autocorrelation,” IEEE Transactions on Information Theory, 85-89, Jan. 1970.
Bingham, J., “Multicarrier Modulation for Data Transmission: An Idea Whose Time Has Come,” IEEE Communications Magazine, 28:5-14, May 1990.
Baig et al., “A Discrete Multitone Transceiver at the Heart of the PHY Layer of an In-Home Power Line Communication Local-Area Network,” IEEE Communications Magazine, 41:48-53, Apr. 2003.
Caire et al., “Bit-Interleaved Coded Modulation,” IEEE transactions on Information Theory, 44:927-946, May 1998.
Fang Yuguang
Kim Byung-Seo
Akerman & Senterfitt
Haile Awet
Meles Pablo
Moe Aung S.
University of Florida Research Foundation Inc.
LandOfFree
Channel estimation and synchronization with preamble using... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Channel estimation and synchronization with preamble using..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Channel estimation and synchronization with preamble using... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4021815