EP1391093A1 - Reconnaissance d'un type de modulation au moyen d'un facteur de rotation de phase marque de la sequence d'apprentissage - Google Patents

Reconnaissance d'un type de modulation au moyen d'un facteur de rotation de phase marque de la sequence d'apprentissage

Info

Publication number
EP1391093A1
EP1391093A1 EP02771624A EP02771624A EP1391093A1 EP 1391093 A1 EP1391093 A1 EP 1391093A1 EP 02771624 A EP02771624 A EP 02771624A EP 02771624 A EP02771624 A EP 02771624A EP 1391093 A1 EP1391093 A1 EP 1391093A1
Authority
EP
European Patent Office
Prior art keywords
training sequence
phase rotation
modulation
output sequence
data
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP02771624A
Other languages
German (de)
English (en)
Inventor
Bin Yang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Infineon Technologies AG
Original Assignee
Infineon Technologies AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Infineon Technologies AG filed Critical Infineon Technologies AG
Publication of EP1391093A1 publication Critical patent/EP1391093A1/fr
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
    • H04L27/20—Modulator circuits; Transmitter circuits
    • H04L27/2003—Modulator circuits; Transmitter circuits for continuous phase modulation
    • H04L27/2007—Modulator circuits; Transmitter circuits for continuous phase modulation in which the phase change within each symbol period is constrained
    • H04L27/2017—Modulator circuits; Transmitter circuits for continuous phase modulation in which the phase change within each symbol period is constrained in which the phase changes are non-linear, e.g. generalized and Gaussian minimum shift keying, tamed frequency modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/0008—Modulated-carrier systems arrangements for allowing a transmitter or receiver to use more than one type of modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/0012—Modulated-carrier systems arrangements for identifying the type of modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
    • H04L27/20—Modulator circuits; Transmitter circuits
    • H04L27/2032—Modulator circuits; Transmitter circuits for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner
    • H04L27/2053—Modulator circuits; Transmitter circuits for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner using more than one carrier, e.g. carriers with different phases
    • H04L27/206—Modulator circuits; Transmitter circuits for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner using more than one carrier, e.g. carriers with different phases using a pair of orthogonal carriers, e.g. quadrature carriers
    • H04L27/2067—Modulator circuits; Transmitter circuits for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner using more than one carrier, e.g. carriers with different phases using a pair of orthogonal carriers, e.g. quadrature carriers with more than two phase states

Definitions

  • the present invention relates generally to digital communication systems, particularly to mobile radio systems.
  • the invention relates in particular to a transmission and reception method and a receiver in a digital telecommunications system according to the preamble of the independent claims.
  • the EDGE (Enhanced Data Rates for GSM Evolution) standard and the associated EGPRS (Enhanced GPRS) package service were defined as the transition standard between the GSM / GPRS and UMTS mobile communications standards. Both the GMSK and the 8-PSK modulation are used in the EDGE standard. GMSK modulation uses a signal space with signal points +1 and -1, while 8-PSK modulation uses a signal space with eight signal points. If the type of modulation to be used in the transmission of information between a transmitter and a receiver is not fixed, the receiver must be informed of the type of modulation used.
  • WO 00/10301 which is hereby incorporated into the disclosure content of the present application, describes a method for transmitting and recognizing the type of modulation in digital communication systems which makes use of the training sequence present in a data burst.
  • Each data burst comprises a predetermined training sequence consisting of a sequence of data symbols known to the receiver, which is used in the receiver for purposes of channel estimation.
  • it is proposed to label every conceivable type of modulation with a certain phase rotation factor and to To apply training phase with the phase rotation factor, ie to rotate the data symbols contained in it with the phase rotation factor.
  • the same phase rotation factor that is also used for the modulation of the user data is preferably used here.
  • the GMSK and the 8-PSK modulation are distinguished by a different symbol rotation. While the GMSK modulation rotates each transmission symbol by 90 degrees, the 8-PSK modulation rotates 67.5 degrees per transmission symbol.
  • the data symbols of the transmitted training sequence which are phase-rotated in this way, can be used in the receiver in such a way that, at the beginning of each data burst, the received training sequence is turned back in a number of data paths by a corresponding number of phase rotation factors.
  • the received training sequence is turned back by 90 and 67.5 degrees, respectively.
  • the received and reversed training sequence is then compared with a training sequence that has been subjected to a channel filter function obtained from a channel estimate. The comparison is made by subtracting these training sequences from each other, adding up the squared differences and detecting the minimum.
  • This method has the disadvantage that a channel estimation must be carried out in each of the data paths provided for the derotation with the different phase rotation factors and only after the channel estimation has been carried out and the original training sequence has been loaded with the channel parameters by the aforementioned channel filter function, the comparison with the received and respectively rotated training sequence can be done.
  • This method is very complex and requires a large number of circuit units in the receiver.
  • the invention is based on the essential knowledge that it is not absolutely necessary to carry out a channel estimation in each data path of the receiver in which the received training sequence is reversed or derotated.
  • the invention deliberately dispenses with channel estimation at this early stage of the detection of the type of modulation. Instead, each received and derotated training sequence is compared directly with the original, unfiltered training sequence. The comparison is made by a correlation, i.e. a multiplication of the two training sequences with each other.
  • the type of modulation is determined according to which phase rotation factor in the respective data path achieves a maximum during the back rotation and the subsequent correlation.
  • the invention is not limited to using the training sequence usually present in a data burst in the manner described.
  • any other sequence of information data that is transmitted during the communication anyway can be used in the manner according to the invention in order to transmit information about the type of modulation.
  • the present invention does not require channel estimates for the detection of the type of modulation, since a correlation between the received and derotated training sequence is carried out with the original, unfiltered training sequence.
  • the original training sequence is therefore not subjected to a channel filter function before the correlation step is carried out.
  • the invention Thus, only a number of data paths are provided in the receiver, in which derotations of the received training sequence are carried out by predetermined phase rotation factors, with a correlation being carried out in each data path following the derotation, in which the received and deroted training sequence with the original, unfiltered Training sequence is correlated.
  • a channel estimation is only carried out after the detection of the type of modulation.
  • Another difference to the generic document mentioned above is the type of mathematical comparison of the training sequences. While the training sequences to be compared are subtracted from one another in the cited prior art, a correlation function is formed according to the invention. If the temporal position of the training sequence within the received data burst is only known to a certain accuracy, provision can also be made for the derotation and correlation to be carried out several times in succession in each data path, the training sequences to be multiplied in the correlation step being incrementally shifted with respect to one another and the maximum correlation result is determined from these multiple correlation steps.
  • the invention is explained in more detail below on the basis of an exemplary embodiment.
  • the exemplary embodiment relates to the use of the two modulation types GMSK (Gaussian minimum shift keying) and 8-PSK (8-ary phase shift keying).
  • GMSK Gausian minimum shift keying
  • 8-PSK 8-ary phase shift keying
  • the GMSK modulation can be approximated by an amplitude modulation and therefore interpreted as follows:
  • the GMSK symbols a are rotated with ⁇ / 2 radians per symbol:
  • ⁇ is the modulated baseband signal, which is mixed with the desired carrier frequency and then transmitted to the antenna.
  • the 8-PSK modulation is defined in a similar way. However, it differs from GMSK modulation in the number of bits mapped to a symbol and in the rotation:
  • An 8-PSK data symbol therefore contains three times the information content as a GMSK data symbol. Therefore the 8-PSK-Mo- dulation is used for high data transmission, while GMSK modulation is used for low data transmission.
  • Both types of modulation can be used with the EDGE standard and the type of modulation can be changed from burst to burst.
  • the EDGE receiver initially does not know the type of modulation in which the data transmitted to it by the transmitter are modulated. For each burst, the EDGE receiver only recognizes a block of complex baseband input data x k and has to make a decision about the type of modulation used. This approach is therefore also called blind modulation detection.
  • information about the type of modulation used is impressed on the transmitted signal and the predetermined training sequence known to the receiver, which is contained in each GSM / EDGE burst, is used for this purpose.
  • the data symbols of the training sequence are rotated on the transmitter side with a phase rotation factor which is also used for the modulation of the useful signals, although in principle another phase rotation factor can also be used for this.
  • This exemplary embodiment of the blind modulation detection method according to the invention is shown schematically in the single drawing figure.
  • the figure shows the flow diagram for blind modulation detection in a receiver.
  • Two samples are generated from a received training sequence xk and fed into two data paths according to the two types of modulation.
  • N denotes the length of the training sequence.
  • the received training sequence Xk is first derotated by - ⁇ / 2 per symbol for GMSK and by -3 ⁇ / 8 per symbol for 8-PSK.
  • the received and each derotated training sequence y k with the original training sequence correlates t k. Since the correlation can have a complex value due to the unknown phase of the signal, the quadratic magnitude of the correlation is calculated after the summation over the products at the individual time moments k.
  • the correlation result between GMSK and 8-PSK is compared. If the received and deroted training sequence y k GMSK is more similar to the original training sequence t k than the received and deroted training sequence y k 8PSK , ie C GMSK > C 8PSK ⁇ w j_ rc j detects that the corresponding data burst with the Modulation type GMSK is modulated. Otherwise it is detected that the modulation type is 8-PSK.
  • the demodulator can then begin channel estimation.
  • the correlation in each data path is carried out several times in succession by shifting the training sequences to be correlated with one another in time.
  • a first correlation can therefore first be carried out in each data path on the basis of certain assumptions about the temporal position of the training sequence.
  • the data symbols of the sequences t k and y k to be correlated can then be fed to the correlator again and slightly offset from one another. The maximum is then selected from several correlations carried out in this way.
  • the method according to the invention for automatic detection of the type of modulation used is characterized by a high degree of accuracy with little effort compared to the prior art.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
  • Synchronisation In Digital Transmission Systems (AREA)

Abstract

Afin de réaliser une détection de modulation aveugle, les symboles de données de la séquence d'apprentissage sont soumis, côté émission, à une rotation d'un facteur de rotation de phase spécifique au type de modulation mis en oeuvre et les symboles de données sont soumis, côté réception, à une rotation inverse de différents facteurs de rotation de phase, puis une fonction de corrélation est établie entre les séquences ainsi obtenues et la séquence d'apprentissage d'origine. On obtient alors le type de modulation mis en oeuvre lorsque le facteur de rotation de phase donne un maximum de la fonction de corrélation.
EP02771624A 2001-05-21 2002-05-06 Reconnaissance d'un type de modulation au moyen d'un facteur de rotation de phase marque de la sequence d'apprentissage Ceased EP1391093A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10124782 2001-05-21
DE10124782A DE10124782B8 (de) 2001-05-21 2001-05-21 Übermittlung und Erkennung der Modulationsart in digitalen Kommunikationssystemen mittels eines der Trainingssequenz aufgeprägten Phasenrotationsfaktors
PCT/DE2002/001623 WO2002096051A1 (fr) 2001-05-21 2002-05-06 Reconnaissance d'un type de modulation au moyen d'un facteur de rotation de phase marque de la sequence d'apprentissage

Publications (1)

Publication Number Publication Date
EP1391093A1 true EP1391093A1 (fr) 2004-02-25

Family

ID=7685624

Family Applications (1)

Application Number Title Priority Date Filing Date
EP02771624A Ceased EP1391093A1 (fr) 2001-05-21 2002-05-06 Reconnaissance d'un type de modulation au moyen d'un facteur de rotation de phase marque de la sequence d'apprentissage

Country Status (5)

Country Link
US (1) US7313204B2 (fr)
EP (1) EP1391093A1 (fr)
CN (1) CN100550871C (fr)
DE (1) DE10124782B8 (fr)
WO (1) WO2002096051A1 (fr)

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US7916811B2 (en) * 2004-02-11 2011-03-29 General Instrument Corporation Method and apparatus for improved burst acquisition in a digital receiver
US7830975B2 (en) * 2004-04-12 2010-11-09 Nokia Corporation I/Q MIMO detection for single antenna interference cancellation
US8107560B2 (en) 2004-05-12 2012-01-31 Telefonaktiebolaget Lm Ericsson (Publ) Method and apparatus for interference cancellation in communication signal processing
JP4256301B2 (ja) * 2004-05-28 2009-04-22 株式会社東芝 無線通信装置
FR2875358B1 (fr) 2004-09-15 2006-12-15 Eads Telecom Soc Par Actions S Insertion d'un flux secondaire d'informations binaires dans un flux principal de symboles d'une modulation numerique
US7382846B1 (en) * 2004-09-29 2008-06-03 Rockwell Collins, Inc. Off-symbol correlation technique
KR100611507B1 (ko) * 2005-02-07 2006-08-11 삼성전자주식회사 무선 통신 수신기에 있어서의 블라인드 디텍션 방법 및장치, 이를 포함하는 무선 통신 수신기
US7697638B2 (en) * 2005-08-16 2010-04-13 Freescale Semiconductor, Inc. Modulation detection in a SAIC operational environment
US7894551B2 (en) * 2005-08-29 2011-02-22 Mediatek Inc. Modulation scheme detecting apparatus and related method
US7724816B2 (en) * 2005-09-13 2010-05-25 Freescale Semiconductor, Inc. Dynamic switching between maximum likelihood sequence estimation (MLSE) and linear equalizer for single antenna interference cancellation (SAIC) in a global system for mobile communications (GSM) system
US8300721B2 (en) * 2007-03-14 2012-10-30 Agilent Technologies, Inc. Pseudorandom noise code acquisition in direct sequence spread spectrum systems
CN101321315B (zh) * 2007-06-08 2011-09-14 华为技术有限公司 发送、接收信号的方法及信号收发设备
US7881365B2 (en) * 2007-10-31 2011-02-01 Agere Systems Inc. Demodulator with configurable adaptive equalizer
BR112012021419A2 (pt) * 2010-02-26 2019-09-24 Ericsson Telefon Ab L M método e disposição para reduzir conjuntamente a relação de potência de pico para potência média e o tipo de modulação de sinal para serviço de rádio de pacote geral aprimorado pré-codificado (egprs).
US9374166B2 (en) * 2012-02-13 2016-06-21 Ciena Corporation High speed optical communication systems and methods with flexible bandwidth adaptation
WO2018172552A1 (fr) 2017-03-24 2018-09-27 Telefonaktiebolaget Lm Ericsson (Publ) Détection de données incohérentes dans une transmission de données

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EP0413153B1 (fr) 1989-07-17 1995-10-18 Nec Corporation Démodulation de phase en quadrature employant un signal d'initialisation et un signal local décalé de la fréquence de la porteuse reçue
US5289476A (en) * 1991-05-10 1994-02-22 Echelon Corporation Transmission mode detection in a modulated communication system
US6473506B1 (en) * 1998-10-13 2002-10-29 Telefonaktiebolaget Lm Ericsson (Publ) Signaling using phase rotation techniques in a digital communications system
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Also Published As

Publication number Publication date
CN1526222A (zh) 2004-09-01
DE10124782A1 (de) 2002-12-12
US20040096012A1 (en) 2004-05-20
US7313204B2 (en) 2007-12-25
WO2002096051A1 (fr) 2002-11-28
DE10124782B4 (de) 2012-06-21
CN100550871C (zh) 2009-10-14
DE10124782B8 (de) 2012-09-13

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