Source: http://www.google.com/patents/US6584164?dq=ascentive
Timestamp: 2014-07-10 08:18:02
Document Index: 672151079

Matched Legal Cases: ['art 104', 'art 105', 'art 106', 'art 104', 'art 106', 'art 104', 'art 104', 'art 105', 'art 104', 'art 105', 'art 106', 'art 104', 'art 106', 'art 104', 'art 104', 'art 105', 'art 104']

Patent US6584164 - Method for forming a training sequence - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsThe invention relates to a method for forming a training sequence in a communication system, in which information is transmitted at one or several carrier frequencies, the training sequence (T) being used at least as a synchronization signal. The training sequence (T) is composed of three or more training...http://www.google.com/patents/US6584164?utm_source=gb-gplus-sharePatent US6584164 - Method for forming a training sequenceAdvanced Patent SearchPublication numberUS6584164 B1Publication typeGrantApplication numberUS 09/379,027Publication dateJun 24, 2003Filing dateAug 23, 1999Priority dateAug 24, 1998Fee statusPaidAlso published asCN1314034A, CN1665231A, CN100345395C, CN100512252C, DE69941121D1, EP1108295A1, EP1108295B1, WO2000011813A1Publication number09379027, 379027, US 6584164 B1, US 6584164B1, US-B1-6584164, US6584164 B1, US6584164B1InventorsVesa TuukkanenOriginal AssigneeNokia CorporationExport CitationBiBTeX, EndNote, RefManPatent Citations (13), Referenced by (18), Classifications (13), Legal Events (3) External Links: USPTO, USPTO Assignment, EspacenetMethod for forming a training sequenceUS 6584164 B1Abstract The invention relates to a method for forming a training sequence in a communication system, in which information is transmitted at one or several carrier frequencies, the training sequence (T) being used at least as a synchronization signal. The training sequence (T) is composed of three or more training parts (103-106; 209-212) by any of the following methods. In the first method, at least two adjacent training parts (103, 104; 209, 210) in the training sequence (T) are formed substantially identical, and furthermore, at least one training part (105, 106; 211, 212) is formed substantially as a negation to said identical training parts (103, 104; 209, 210). In the second method, at least two adjacent training parts (103, 104; 209, 210) in the training sequence (T) are formed substantially identical, and furthermore, at least one training part (105, 106; 211, 212) is formed substantially different from said identical training parts. In the third method, at least two adjacent training parts (103, 104; 209, 210) in the training sequence (T) are formed substantially as negations to each other, and furthermore, at least one training part (105, 106; 211, 212) is formed substantially different.
BRIEF SUMMARY OF THE INVENTION It is a purpose of the present invention to provide a method for forming training parts in such a way that the synchronization of the receiver with the transmitted signal is improved with respect to using training parts of prior art. The invention is based on the idea that the training sequence is formed in such a way that correlation of two subsequently received training sequences results in at least one peak, preferably an alternating positive and negative peak. This is achieved preferably in such a way that at least two subsequent training parts in the training sequence are identical, and at least one training part is the negation of these. The method according to the present invention is characterized in that the training sequence is composed of three or more training parts in such a way that in the training sequence:
DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows in a reduced manner a part of the beginning of a data frame 101 containing a training sequence T according to a first advantageous embodiment of the invention. In this context, the training sequence T refers to an information sequence formed of one or several parts in a data frame. Training sequences T are placed in the beginning of data frames 101 (physical data unit, PDU) before the actual information to be transmitted, wherein in the receiver, the training sequence T is used particularly to determine the timing shift and the frequency shift, and to evaluate of the features of the communication channel. Consequently, a data frame consists of OFDM symbols, some of which are used for transmitting training parts and some for transmitting information. A first header 102 in a data frame (automatic gain control, AGC) is intended for adjusting the amplification of the receiver according to the strength of the received signal, which is known as such. The data frame 101 of FIG. 1 consists of symbols having a length of N samples. In this embodiment, the length of the training sequence T is four training parts, each forming one OFDM symbol. These training parts are indicated with reference numbers 103, 104, 105 and 106. In the receiver, the correlation between two subsequent training parts is determined on the whole length of the training sequence. Consequently, in this example, three correlations are determined: between the first 103 and second training part 104, between the second 104 and third training part 105, and between the third 105 and fourth training part 106, respectively. These training parts are preferably formed in a way that subsequent correlations result in a positive and a negative maximum (peak), alternatingly. This is obtained so that the first 103 and second training part 104 are substantially identical and the third 105 and fourth training part 106 are preferably substantially negations to the first 103 and second training part 104. In other words, the first 103 and second training part 104 correlate well with each other, the third training part 105 correlates well but negatively with the second training part 104, and the third training part 105 correlates well with the fourth training part 106. However, the invention can also be applied in a way that the correlations of subsequent training parts result either in a peak (positive or negative) or a value close to zero. This can be obtained e.g. in a way that the first 103 and second training part 104 are substantially identical or negations to each other, and that the third 105 and possibly also the fourth training part 106 differs substantially from the first 103 and second training part 104 but are not negations to them. Consequently, the first 103 and second training part 104 correlate well with each other but the third training part 105 correlates poorly with the second part 104. Furthermore, it should be mentioned that even though subsequent training parts were not fully identical or identical negations to each other, the peaks in the correlation results can still be found but the evaluation accuracy is not necessarily as good.
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2002May 4, 2004Arraycomm, Inc.Training sequence for a radio communications systemUS6810087 *Jan 3, 2001Oct 26, 2004General Electric CompanyUltra-wideband communications systemUS6856590 *Apr 12, 2001Feb 15, 2005Sony CorporationOFDM transmission device and OFDM transmission methodUS6967994 *Sep 7, 2001Nov 22, 2005Agere Systems Inc.Method for operating a communication system and a communication system with training meansUS7251288 *Feb 22, 2001Jul 31, 2007Sharp Kabushiki KaishaWireless communication transmitter and receiverUS7561626Jun 9, 2004Jul 14, 2009Marvell World Trade Ltd.Method and system for channel estimation in a data transmission systemUS7561627Jan 6, 2005Jul 14, 2009Marvell World Trade Ltd.Method and system for channel equalization and crosstalk estimation in a multicarrier data transmission systemUS7643582Jun 9, 2004Jan 5, 2010Marvell World Trade Ltd.Method and system for determining symbol boundary timing in a multicarrier data transmission systemUS7697619Jun 9, 2004Apr 13, 2010Marvell World Trade Ltd.Training sequence for channel estimation in a data transmission systemUS7801233Jun 18, 2009Sep 21, 2010Marvell World Trade Ltd.Method and system for channel equalization and crosstalk estimation in a multicarrier data transmission systemUS7817730Jun 9, 2004Oct 19, 2010Marvell World Trade Ltd.Training sequence for symbol boundary detection in a multicarrier data transmission systemUS8059750 *Feb 8, 2008Nov 15, 2011Samsung Electronics Co., LtdMethod and apparatus for generating training sequence code in a communication systemUS8265215Dec 1, 2009Sep 11, 2012Marvell World Trade Ltd.Method and system for determining symbol boundary timing in a multicarrier data transmission systemUS8666734 *Sep 23, 2010Mar 4, 2014University Of Maryland, College ParkSystems and methods for multiple pitch tracking using a multidimensional function and strength valuesUS20110071824 *Sep 23, 2010Mar 24, 2011Carol Espy-WilsonSystems and Methods for Multiple Pitch TrackingUS20110170482 *Jan 19, 2009Jul 14, 2011Qualcomm IncorporatedMethod and apparatus for signaling to a mobile device which set of training sequence codes to use for a communication linkWO2005125141A1 *Jun 6, 2005Dec 29, 2005Hk Applied Science & Tech ResTraining sequence for symbol boundary detection in a multicarrier data transmission systemWO2008097036A1 *Feb 5, 2008Aug 14, 2008Samsung Electronics Co LtdMethod and apparatus for generating training sequence code in a communication system* Cited by examinerClassifications U.S. Classification375/365, 370/503, 375/259, 375/316, 375/295International ClassificationH04L7/00, H04L27/26, H04J11/00, H04L7/04Cooperative ClassificationH04L7/041, H04L27/2613European ClassificationH04L7/04B, H04L27/26M1R3Legal EventsDateCodeEventDescriptionNov 24, 2010FPAYFee paymentYear of fee payment: 8Dec 1, 2006FPAYFee paymentYear of fee payment: 4Aug 23, 1999ASAssignmentOwner name: NOKIA CORPORATION, FINLANDFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TUUKKANEN, VESA;REEL/FRAME:010195/0376Effective date: 19990726RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google