EP1356406A2 - Procede permettant de faire fonctionner un recepteur de messages - Google Patents

Procede permettant de faire fonctionner un recepteur de messages

Info

Publication number
EP1356406A2
EP1356406A2 EP01967619A EP01967619A EP1356406A2 EP 1356406 A2 EP1356406 A2 EP 1356406A2 EP 01967619 A EP01967619 A EP 01967619A EP 01967619 A EP01967619 A EP 01967619A EP 1356406 A2 EP1356406 A2 EP 1356406A2
Authority
EP
European Patent Office
Prior art keywords
burst
receiver
synchronization
sequence
synchronized
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.)
Withdrawn
Application number
EP01967619A
Other languages
German (de)
English (en)
Inventor
Khaled Fazel
Volker Hespelt
Volker Engels
Bernd Friedrichs
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.)
Ericsson AB
Original Assignee
Marconi Communications GmbH
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 Marconi Communications GmbH filed Critical Marconi Communications GmbH
Publication of EP1356406A2 publication Critical patent/EP1356406A2/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L7/00—Arrangements for synchronising receiver with transmitter
    • H04L7/04—Speed or phase control by synchronisation signals
    • H04L7/041—Speed or phase control by synchronisation signals using special codes as synchronising signal
    • H04L7/042—Detectors therefor, e.g. correlators, state machines

Definitions

  • the invention relates to a method for operating a message receiver for a message which is in the form of a burst and which comprises at least one training sequence and user data.
  • bursts are used for the transmission of messages or data. These bursts are transmitted in series, fixed time slots according to the known TDMA (time division multiple access) method.
  • TDMA time division multiple access
  • a burst comprises at least one training sequence and useful or signaling data, it being possible for the training sequence to precede the useful data.
  • This training sequence is therefore also referred to as a preamble.
  • other TDMA methods are also known in which the training sequence is in the middle of two user data blocks as a midamble is transmitted. Of course, the training sequence can also be attached to the end of the user data block.
  • the training sequence on the message receiver is such that it can synchronize with the burst to be received, so that data transmission from a base station to a terminal station and vice versa is possible via an air interface.
  • this must be synchronized to at least the carrier frequency and the phase position of the carrier frequency of the burst.
  • two techniques are known for the synchronization, with one variant for the synchronization evaluating the useful data stream, in particular statistically. This variant is also known as data-supported synchronization. In another variant, the
  • Synchronization based on pilot tones that are sent as a training sequence.
  • the parameters for the synchronization are based on
  • Another data-supported synchronization is based on a method from Viterbi & Viterbi, in which MPSK-modulated symbols are synchronized by means of a non-linear transformation of the received message, which is in the form of complex symbols, by averaging and the phase position of the receiver.
  • the algorithm used according to this Viterbi & Viterbi method requires a predetermined interval of data to enable the averaging.
  • a disadvantage of this method is that the phase position can only be determined if there is a low frequency offset between the transmitter and the receiver. However, this is rarely guaranteed, especially when data is transmitted via Lu interfaces, since the transmitted signals are multipath and above in addition, there is no frequency coupling between the message receiver and transmitter.
  • GSM mobile radio user data and signaling and control information are also transmitted according to the well-known TDMA experience. Because essentially only speech is to be transmitted, there is a low data rate for the user data.
  • the physical channel time slot on a predetermined frequency
  • the physical channel is divided into several logical channels for the transmission of the control and signaling information. This means that signaling and control information is transmitted once in an allocated time slot and useful data is transmitted in the next slot at the same slot location.
  • a training sequence is sent with both the user data and the signaling and control information, which is located in the middle between two user data packets in GSM mobile radio and is therefore referred to as the midambel. Because the physical channel, ie the time slot on one frequency, is divided into several logical channels in which all the necessary data is transmitted however, the transmission rate for the user data is too low for multimedia applications.
  • a synchronization is also known in which, for example, two pseudo-noise sequences are transmitted as midambles in one time slot. According to these evaluation algorithms, there is a synchronization for both the carrier frequency and the Phase position possible, however, considerable effort must be made for the time synchronization.
  • the receiver is pre-synchronized so that further synchronization parameters can be determined more quickly, since the symbol evaluation can be carried out more easily by the pre-synchronized receiver.
  • the total synchronization time is thus advantageously reduced.
  • This makes it possible to use the message receiver in a multimedia transmission system in which a high data rate of user data has to be transmitted in order to be able to efficiently display images or image and / or sound sequences.
  • the method according to the invention can also be used in other transmission systems with high data transmission rates.
  • the receiver is synchronized in its step-by-step synchronization during a first synchronization step to the clock of the message and the phase position of the carrier frequency of the burst. This embodiment is preferred if the frequency offset is low or negligible. In another embodiment, the receiver is synchronized to the clock of the message and the carrier frequency of the burst during the first synchronization stage. This variant is preferred if the phase shift is small.
  • the receiver is synchronized to the time slot of the burst during a second synchronization stage.
  • the receiver is thus synchronized to the physical channel.
  • a further development of the invention provides that the transmission channel impulse response and / or the automatic gain control (AGC) is calculated during the second synchronization stage.
  • the air interface ie the radio transmission link, can be monitored so that a channel adjustment is possible.
  • the receiver is synchronized to the carrier frequency of the burst during the second synchronization stage.
  • This variant is used in particular if the clock and the phase position were determined during the first synchronization stage.
  • a fine adjustment of the receiver to the carrier frequency is possible during the second synchronization stage. If the clock and the carrier frequency were determined in the first synchronization stage and the receiver was accordingly pre-synchronized, the receiver is synchronized to the phase position of the carrier frequency during the second synchronization stage.
  • the post-synchronization of the phase position or the carrier frequency is provided when the user data are to be evaluated.
  • the receiver is synchronized with the phase and / or frequency of the carrier frequency.
  • This synchronization also referred to as tracking, is provided in particular when the phase position and / or frequency of the carrier signal fluctuate during a burst. The tracking is therefore carried out in a preferred embodiment during the decoding of the useful data.
  • a Viterbi decoder is used for tracking and decoding the user data.
  • the tracking can also be carried out according to the Viterbi & Viterbi algorithms known per se.
  • the Viterbi decoder and the Viterbi & Viterbi algorithms are characterized in particular by the fact that they can be used to make preliminary decisions that ultimately enable tracking.
  • the training sequence at least comprises two sub-sequences.
  • the partial sequences are designed in such a way that the step-by-step synchronization of the receiver is facilitated.
  • one of the partial sequences is periodic in itself, as a result of which the phase position and / or the carrier frequency and / or the symbol clock can be determined particularly easily and quickly.
  • one of the partial sequences that is periodic in itself is thus evaluated during the first synchronization stage.
  • At least one 'of the partial sequences comprising a symbol sequence, which enables an adjustment of the time slot of the burst and a calculation of the transmission channel impulse response, the phase position, the automatic input gain control (AGC) and the transmission power.
  • Either partial sequences that comprise pilot tones or partial sequences that have pseudo-noise sequences (PN sequences) can be provided for this.
  • PN sequences pseudo-noise sequences
  • possible combinations are also possible, so that one partial sequence has pilot tones and the other partial sequence has the pseudo-noise sequences.
  • both partial sequences can have pilot tones or the pseudo-noise sequences.
  • User data can be statistically evaluated. Can be then it would be sufficient, for example, only a partial sequence with pilot tones to be transmitted, so that the first synchronizing carried out '. Out The remaining synchronization parameters of the received user data can then be determined by statistical evaluation and the second synchronization stage can be carried out.
  • the training sequence has a constant duration or number of symbols, regardless of the number of partial sequences. This enables the receiver to be easily synchronized using the training sequence known to him - codes or symbol sequences.
  • an incoming burst is detected by means of a power detection at the receiver.
  • the power detection serves as a kind of trigger - (Start) signal for the start of the gradual On - ⁇ synchronization of the receiver.
  • the time slot structure is determined for the incoming burst. This means that the number of symbols in the user data is evaluated. This makes it easy to determine whether user data is actually being transmitted or whether control or signaling information is being transmitted, which usually has a smaller number of symbols within the data packet.
  • the transmission channel impulse response is calculated by cross-correlating the burst and the second partial sequence.
  • the transmission channel impulse response is calculated by cross-correlating the burst and the second partial sequence.
  • the training sequence is shifted by a predeterminable number of symbols in order to determine the corresponding number of multipath propagation echoes, from which the phase position and amplitude of each multipath propagation can then be determined in a preferred embodiment.
  • the AGC parameters can be determined in a particularly simple manner from the phase position and the amplitude of the individual multipath propagation echoes.
  • the constant phase position which is also referred to as the static phase position, is determined for each multipath propagation.
  • the periodic partial sequence is evaluated in the time domain. This enables the pilot tones to be determined from which the frequency and / or phase position can be determined.
  • the other partial sequence which is used in particular for the second synchronization stage, is evaluated in the preferred embodiment in the complex number range, so that the complex number lencru with real and imaginary part the phase position and frequency can be derived directly.
  • burst eats the training sequence as a preamble.
  • FIG. 1 shows a data transmission network with a base station and several terminal stations
  • FIG. 2b different packet structures of a message for the transmission from the base station to the terminal stations
  • FIG. 2c different packet structures for the direction of transmission from a terminal station to the base station
  • FIG. 3 shows a block diagram of a transmission chain from a terminal station to the base station
  • FIG. 4 shows a block diagram for the synchronization of a burst
  • FIG. 5 shows a sequence diagram of a burst synchronization
  • FIG. 6 shows a block diagram for the first synchronization stage according to a first exemplary embodiment
  • FIG. 7 shows a block diagram of the first synchronization stage according to a second exemplary embodiment
  • FIG. 8 shows a block diagram for the second synchronization stage
  • FIG. 9 shows a block diagram for tracking according to a first exemplary embodiment
  • Figure 10 is a block diagram for the second synchronization stage according to a second embodiment.
  • Figure 11 shows the burst synchronization of a receiver in an overall view. Description of the embodiments
  • FIG. 1 shows a detail of a data transmission network 1, which has at least one base station 2 and one or more terminal stations 3 as network elements, which can exchange data with the base station 2 via an air interface 4. Data transmission from base station 2 to terminal stations 3 is also possible via interface 4.
  • the base station thus has at least one transmitter 5 and one receiver 6. Accordingly, the terminal stations 3 are each equipped with at least one transmitter 7 and one receiver 8.
  • the base station 2 can be coupled to a network 9, which is, for example, a public communication network.
  • the transmission links in this network 9 can be wired or implemented as air interfaces.
  • the terminal stations 3 can be connected to a network 10, wherein each of the networks 10 is preferably a local network to which a plurality of end acceptance devices (not shown) can be connected.
  • the terminal stations 3 are arranged so as to be stationary. However, it would also be conceivable that the terminal stations 3 are designed as mobile stations.
  • the base station 2 is preferably also immobile.
  • the data transmission network 1 is in the form of a cellular network in which the terminal stations 3 are different Distances to the base station 2 can be arranged.
  • the data transmission network 1 is particularly preferably used for the transmission of multimedia services, in which a correspondingly high data transmission rate is to be realized in order to be able to provide multimedia services in real time.
  • a burst operation is provided for the transmission of the data, in which signal bundles, also referred to as bursts, are transmitted via the air interfaces 4.
  • These bursts are preferably transmitted using TDMA technology, in which a plurality of time slots are provided on a transmission or carrier frequency, it preferably being provided that at least one time slot has access to one of the terminal stations 3.
  • point-to-multi-point 'data transmission network 1 with cellular Auftei- lung individual network sectors owns the base station 2 for transmission, one or more directional antennas are directed to the terminal stations 3 and aligned.
  • the individual frequency channels are preferably in a frequency carrier from 3.5 to 28 GHz. Of course, other frequency ranges can be selected.
  • the data are transmitted as bursts according to the TDMA method.
  • each of the terminal stations 3 is assigned at least one time slot in which a TDMA burst is transmitted.
  • gene which is identified in FIG. 2a with the reference number 11.
  • Such a TDMA burst 11 comprises at least one user data packet 12, at least one training sequence 13 and a guard time 14 during which nothing is transmitted in order to avoid influencing adjacent time slots.
  • the burst 11 has the following preferred structure:
  • the training sequence 13 is sent as a preamble 13 ', that is to say that it is connected upstream of the user data packet 12, the user data packet 12 being before the protection time 14.
  • the training sequence 13 lies between two partial user data packets, that is to say is sent as a midamble. Furthermore, it would be conceivable that the training sequence 13 is appended to the user data packet 12, wherein it is preferably sent between the user data packet 12 and the guard time 14.
  • the receiver 6 in the base station 2 can synchronize itself very quickly with the burst sent by the terminal stations 3, so that one rapid demodulation and decoding of the burst 11 is ensured since the data transmission speed ultimately depends on it.
  • the receiver 6 of the base station 2 is synchronized step by step with the received burst 11 in the embodiment according to the invention.
  • the training sequence 13 is divided into two partial sequences 15 and 16, the one in the two partial sequences 15 and 16 contained symbols or the information reflected by the symbols is coded or modulated such that each partial sequence 15 and 16 can be decoded and evaluated on its own, so that the information contained in the partial sequences 15 and 16 for the step-by-step synchronization of the Receiver 6 can be used.
  • the partial sequence 15 has a number N of symbols; the partial sequence 16 a number M of symbols, where N and M can be different or the same.
  • the first partial sequence contains 15 pilot tones, with which the first synchronization stage e of the receiver 6 can be carried out, in such a way that the symbol clock of the burst 11 and the phase position of the carrier frequency of the burst are first synchronized. However, it can also first be synchronized to the symbol clock of the message and to the carrier frequency of the burst. Because this first synchronization stage is carried out at the receiver 6 of the base station 2, the second partial sequence 16 can be evaluated faster and more reliably for the second synchronization stage, since the pre-synchronization or the first synchronization stage means that the second partial sequence can be decoded faster and more reliably Information is possible. As mentioned above, pilot tones are preferably transmitted in the first partial sequence.
  • the second sub-sequence 16 preferably contains symbol sequences which enable the time slot of the burst to be compared and the transmission channel impulse response to be calculated.
  • symbol sequences preferably transmitted symbol sequences that comprise at least two sequences of a pseudo-noise.
  • AGC Automatic Gain Control
  • the receiver 6 can be synchronized with the phase and / or frequency of the carrier sequence.
  • the terminal stations 3 and the base station 2 contain a protocol unit for the transmission and reception control, which operates according to the ATM / MAC protocol.
  • the terminal stations 3 and the base station 2 comprise a modem with which the TDMA bursts 11 can be received and sent.
  • known intermediate frequency and radio frequency parts are contained in the transmitters or receivers of the base station 2 and the terminal station 3.
  • the transmission channel access control unit controls access for individual transmitters or receivers to the divided TDMA channel. It also manages
  • MAC controller controls the access requirements for the transmission channel and the available channel reserves.
  • the MAC control unit For the direction of transmission from the terminal stations 3 to the base station 2 (uplink), the MAC control unit requires transmission reserves for signaling monitoring (signaling overhead). Each terminal is 3 for data transmission and the base station 2 is connected to an ATM interface. After this ATM interface is the modem mentioned above, from which ATM cells and signaling data can be received and sent. Dynamic time slot allocation (DSA, Dynamic Slot Allocation) is provided for this purpose for the MAC protocol.
  • DSA Dynamic time slot allocation
  • the time slots provided for this are divided into signaling periods.
  • the DSA-MAC protocol is used for this grouping or division.
  • a signaling period is initiated by a period control PDU in the transmission direction from the base station 2 to the terminal stations 3. This direction of transmission is also referred to as downlink.
  • the period control PDU signals the number of time slots in the next signaling period and the assigned MAC connection.
  • a signaling period can contain a variable number of very short slots, especially for the request channel (RQCH).
  • RQCH request channel
  • FIGS. 2b and 2c must be observed for the MAC control unit.
  • the signal packet structures for the downlink are shown in FIG. 2b.
  • Figure 2c shows the packet structures for the uplink.
  • nx 53 ATM cell bytes are provided. So a total of nx 53 + 5 bytes are transmitted.
  • This data packet has only five bytes, one byte for the MAC identification (MAC-Id) and four bytes for the request channel (request channel). This data packet type is usually used for random access or polling mode.
  • the packet structures shown in FIG. 2c can be transmitted within the user data packet s 12 in FIG. 2a. That is, the data packets shown in Figure 2c are transmitted within the burst 11 nen k ⁇ n- '.
  • the packet structures shown in FIG. 2b are also transmitted in the burst 11 shown in FIG. 2a.
  • the step-by-step synchronization of the receiver can be provided for both the uplink and the downlink.
  • FIG. 11 showing an overall overview of the components shown separately in FIGS. 3 to 10.
  • the transmitter 8 of a terminal station 3 has several structural units, which are shown as a block diagram.
  • a coding input Direction 17 digital information D are supplied, which are then encoded in the coding device 17.
  • the coding device can comprise a block coding device 18, in which the digital information D is coded with an (outer) block code, which is used for correcting / detecting errors.
  • the coding device 17 can also have a convolutional code coding device 19, in which the digital information D can be provided with an error-correcting (inner) code.
  • Downstream of the coding device 17 is a modulation unit 20, which is also referred to as a symbol mapper, in which the coded digital information is modulated in accordance with the modulation specifications.
  • modulation unit 20 is followed by a device 21 that defines or produces the frame structure of a burst 11. This means that the training sequence 13 as well as start and end bits are added to the modulated digital information, ie the user data packet 12.
  • a multiplexer is also present in the device 21, which sets the completed bursts 11 to the correct time slot.
  • training sequences 13 are stored in a memory device 22. Such training sequences are preferably used, the symbol sequence of which cannot be formed by a user data packet, so that a confusion between User data package and training sequence is excluded.
  • a transmit filter 23 Downstream of the device 21 is a transmit filter 23, to which a digital mixer 24 connects, in which a burst 11 is set to a digital intermediate frequency IF.
  • the digital mixer 24 is followed by a digital-to-analog converter, from which the signals, which are now analog, are transmitted via the air interface 4 to the receiver 6 of the base station 2.
  • the receiver 6 On the input side, the receiver 6 has an analog-digital converter which is followed by a digital mixer 25 which mixes the now digital signals with a digital intermediate frequency IF.
  • a digital mixer 25 which mixes the now digital signals with a digital intermediate frequency IF.
  • corresponding demodulation and decoding devices are provided on the receiver side in accordance with the coding and modulation provided on the transmitter side.
  • these are an input filter 26, which is also referred to as a matched filter or signal-adapted filter, which can be designed as a square root Nyquist filter.
  • a demultiplexer 27 is provided on the receiver side.
  • a recovery device 28 For the recovery of the original information, a recovery device 28 is provided, which comprises a Viterbi decoder 29 and block code decoder 30.
  • the digital message is mixed down to the digital intermediate frequency IF by means of the digital mixer 25.
  • a synchronization direction 31 is provided, which synchronizes the entire recipient 6 to the received message.
  • the training sequence is received by the synchronization device 31 after the input filter 26 in order to determine at least the clock frequency, the carrier frequency and / or the carrier phase therefrom, so that the receiver-side components can be synchronized via synchronization control lines 32.
  • a frequency-phase correction device 33 is provided between the input filter 26 and the demultiplexer 27 for frequency or phase correction.
  • the Viterbi decoder 29 can be used to carry out the tracking after the synchronization, in which the synchronization for the phase and / or the frequency is established.
  • the parameters for the tracking determined by the Viterbi decoder 29 are transmitted to the synchronization unit 31, which can thus re-synchronize the receiver-side modules.
  • the Nyquist filter is provided with the reference number 35 in FIG. This filter 35 is used for pulse shaping.
  • the interpolation filter 34 has an interpolation factor I.
  • the receiver 6 shown in detail in FIG. 4 has the analog / digital converter and the digital one Mixer 25, to which the digital intermediate frequency IF is fed. Furthermore, the input filter 26 is shown, which can comprise a Nyquist filter 36 and a decimation filter 37, which has a decimation factor d.
  • the synchronizing device 31 here has in detail a power or energy detector 38 which detects an incoming burst at the receiver 6. Information from the MAC protocol is fed to this detector 38.
  • a detection device for the carrier frequency, clock frequency or phase position of the carrier frequency is also arranged in the synchronization device 31 and is provided with the reference number 39 in FIG.
  • the detection device 39 determines the corresponding synchronization parameters from the signal taken after the filter 36 and transmits control pulses to the digital mixer 25 and a device 40 for synchronizing the position of the phase or frequency.
  • the detection device 39 and the equalization manufacturing device 40 are also supplied with the signal present after the decimation filter 37.
  • the device 40 receives information from the Viterbi decoder 29 for the synchronous position. Between the decimation filter 37 and the demultiplexer 27 there is a phase / frequency correction unit or a complex multiplier 25 'in order to establish the synchronization with respect to phase or frequency.
  • a tap for a device 41, which performs the transmission channel ⁇ -Impulsantwort and the time slot synchronization and corresponding information to the demultiplexer 27 about ittelt.
  • the device 41 also provides information for time slot alignment and input gain (AGC).
  • FIG. 5 shows a block diagram for the step-by-step synchronization of the receiver 6.
  • the received signal D is detected by the power detector 38.
  • the rough synchronization with regard to clock and frequency or phase position of the carrier frequency is carried out.
  • the first partial sequence 15 is evaluated from the received signal D, which is represented by a flow arrow 43.
  • the demultiplexer 27 is synchronized with respect to the phase or frequency and clock by means of the correction device 33.
  • the second partial sequence 16 is evaluated in the second synchronization stage 45.
  • the transmission of the second training sequence is identified by the diagram flow arrow 44.
  • the time slot alignment and the transmission channel impulse response (CIR) are evaluated.
  • the receiver is then synchronized with respect to the slot alignment and the transmission channel impulse response by means of a second correction device 33 '.
  • Steps 42 and 45 thus determine the parameters necessary for the synchronization of the receiver. Either the clock or the frequency or the clock and the phase of the received burst are determined during step 42, the first training sequence being used for this. In method step 45, the necessary parameters for the time slot alignment and the transmission channel impulse location are determined. In addition, the phase can also be determined in the second synchronization stage 45, in particular when the clock and the frequency have been determined in the first synchronization step. The AGC mentioned above can also be determined.
  • the evaluation of the first partial sequence 15, which is represented here purely by way of example by pilot tones (++ - ++ --7), is carried out in such a way that the received first partial sequence 15 is fed to two low-pass filters 46a and 46b, whereby a linear regeneration unit 47 is connected downstream of each filter 46a and 46b.
  • the clock and frequency offset are then determined in a calculation unit 48, so that the parameters obtained can be transmitted to the elements connected downstream of the calculation unit 48.
  • the first partial sequence 15 is formed here by pilot tones.
  • the parameters mentioned above are determined from these pilot tones. This procedure is very similar to the pilot tone technique known per se, in which all procedures are carried out in the time domain.
  • the received signal corresponds to a signal with an essentially cosine shape, so that the Fourier transformation of this signal results in two pilot tones which contain the frequency offset and the clock information.
  • the clock and frequency offset can be derived.
  • the phase offset is preferably calculated during the second synchronization stage 2S by means of the second partial sequence 16.
  • the phase shift and clock are first determined.
  • the first partial sequence 15 is in turn supplied to two filters 46a and 46b, a phase detector 49 being attached to the filter 46a and a time detector 50 being attached to the filter 46b.
  • the phase shift and clock are then determined in an average value determination device 51 and passed on to the downstream devices. If this variant is given preference, the frequency offset is preferably calculated during the second synchronization stage and the receiver is synchronized to it.
  • the signal which has already been pre-synchronized is further processed, in accordance with FIG. 8, for carrying out the second synchronization stage 2S.
  • the second partial sequence 16 is used for time slot synchronization (slot alignment) based on a correlation process.
  • the time slot For a basic search or monitor function in order to be able to detect all symbols within the time slot, the time slot must be evaluated symbol by symbol. Reduced symbol intervals are taken into account in that the MAC protocol knows whether it is a time slot with user data or just a burst with channel request information, the MAC ID (FIG. 2c) being evaluated for this purpose can.
  • the received user data are correlated with the second partial sequence in a device 53.
  • a parallel or subsequent search for a maximum deflection (peak) is carried out in a device 54 in order to be able to carry out the time slot synchronization in a method step 55.
  • the received time slot and the second partial sequence 16 are then correlated with one another again, the cross-correlation preferably being used here, this being done by shifting by a number P of symbols of the first training sequence in a method step 56.
  • the transmission channel impulse response or the amplification factor (AGC) can then be determined from this in subsequent method steps 57 and 58.
  • the received signal is delayed in a method step 59 by a number of saraples.
  • a non-linear transformation of the received signal takes place in a method step 61.
  • the calculated phase parameters and the static phase are combined with one another, the static phase from the training sequence being determined in a method step 63 by correlation.
  • the combined values for the synchronous position are then used via the complex multiplier 25 '.
  • the same parts or parts having the same effect as in the other figures are otherwise provided with identical reference numerals.
  • Establishing synchronism with regard to frequency and / or phase is therefore necessary in many cases, since influences from the known jitter and Doppler effects or the like can exist, as a result of which the phase position changes over the length of a time slot, in particular in the case of a user data time slot can, so that only a one-time correction to the corresponding phase position with a calculated value is not satisfactory in all cases.
  • the bit error rate can thus be reduced with the synchronous position with regard to phase and / or frequency.
  • An improvement can also be achieved if a combination of the first and second partial sequences is taken into account in such a way that one of the partial sequences comprises the pilot tones and symbols are contained in the second partial sequence which deliver good correlation results.
  • a Viterbi & Viterbi algorithm can also be used to establish synchronism with regard to phase and / or frequency be processed in a V & V facility ( Figure 11). The parameters delivered by this device V & V are then used for the tracking.
  • FIG. 9 An alternative to the method described in FIG. 9 can be seen in that a reconstruction of an equivalent input signal D 1 (FIG. 10) is carried out by means of the Viterbi decoder 29, after which a phase comparison between the received signal and the reconstructed (again established) signal is carried out.
  • a start value is preferably used, namely that which was calculated as a phase offset during the first synchronization stage IS. If the phase shift was determined during the second synchronization stage, this value can of course also be used as the start value.
  • This process is shown as a flow diagram in Figure 10.
  • the same or equivalent parts as in the other figures are provided with the same reference numerals.
  • a signal reconstruction device 64 and a phase comparator 65 are provided in order to compare the signal tapped after the demultiplexer 27 with the signal reconstructed from the device 64 in order to calculate the different phase position sets during tracking.
  • the receiver can then be synchronized accordingly with the combination device 62.

Landscapes

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

Abstract

Procédé permettant de faire fonctionner un récepteur de messages pour un message se présentant sous forme de rafale qui contient au moins une séquence d'entraînement et des données utiles. Ledit procédé se caractérise en ce que lors de la réception de la rafale, le récepteur est synchronisé par étapes sur la rafale.
EP01967619A 2000-08-17 2001-08-13 Procede permettant de faire fonctionner un recepteur de messages Withdrawn EP1356406A2 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10040222A DE10040222A1 (de) 2000-08-17 2000-08-17 Verfahren zum Betreiben eines Nachrichten-Empfängers
DE10040222 2000-08-17
PCT/IB2001/001760 WO2002015065A2 (fr) 2000-08-17 2001-08-13 Procede permettant de faire fonctionner un recepteur de messages

Publications (1)

Publication Number Publication Date
EP1356406A2 true EP1356406A2 (fr) 2003-10-29

Family

ID=7652746

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01967619A Withdrawn EP1356406A2 (fr) 2000-08-17 2001-08-13 Procede permettant de faire fonctionner un recepteur de messages

Country Status (5)

Country Link
US (1) US7346138B2 (fr)
EP (1) EP1356406A2 (fr)
CN (1) CN1305249C (fr)
DE (1) DE10040222A1 (fr)
WO (1) WO2002015065A2 (fr)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7532673B2 (en) * 2004-01-30 2009-05-12 Scientific-Atlanta, Inc. Transport of modulation symbols in a communications system
DE102004039016A1 (de) * 2004-08-11 2006-02-23 Rohde & Schwarz Gmbh & Co. Kg Verfahren und Vorrichtung zum Schätzen der Frequenz und/oder der Phase mit blockweiser Grobschätzung
US8170047B2 (en) * 2005-05-09 2012-05-01 Qualcomm Incorporated Data transmission with efficient slot and block formats in a wireless communication system
US7689132B2 (en) * 2005-06-07 2010-03-30 Industrial Technology Research Institute Interference-rejection coding method for an optical wireless communication system and the optical wireless communication system thereof
EP2076980B1 (fr) * 2006-10-18 2018-12-12 Electronics and Telecommunications Research Institute Procédé de recherche de cellules par tdm pour système ofdm
JP4271228B2 (ja) * 2006-11-08 2009-06-03 オリンパス株式会社 受信装置
US8401600B1 (en) 2010-08-02 2013-03-19 Hypres, Inc. Superconducting multi-bit digital mixer
PL2956422T5 (pl) 2013-02-14 2023-03-20 Agc Glass Europe Oszklenie przeciwsłoneczne
DE102013218212A1 (de) * 2013-09-11 2015-03-12 Robert Bosch Gmbh Verfahren zum abgesicherten Übermitteln von Daten

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4599732A (en) 1984-04-17 1986-07-08 Harris Corporation Technique for acquiring timing and frequency synchronization for modem utilizing known (non-data) symbols as part of their normal transmitted data format
JP2702303B2 (ja) * 1991-03-20 1998-01-21 日本電気株式会社 データ通信方式
SE469678B (sv) * 1992-01-13 1993-08-16 Ericsson Telefon Ab L M Saett foer synkronisering och kanalestimering i tdma- radiosystem
CN1124716C (zh) * 1993-09-10 2003-10-15 德国汤姆逊-布朗特公司 在ｏｆｄｍ系统中传输参考信号的方法
US5625573A (en) * 1995-03-01 1997-04-29 Hughes Electronics Fast acquisition of GMSK-modulated signal for CDPD applications
DE19511403A1 (de) * 1995-03-28 1996-10-02 Siemens Ag Automatische Bursterkennung bei Vielfachzugriffsverfahren
GB2309859B (en) * 1996-01-31 2000-02-16 Nokia Mobile Phones Ltd Radio receivers and methods of operation
US5883929A (en) * 1996-04-03 1999-03-16 Ericsson, Inc. Synchronization method, and associated circuitry, for synchronizing a receiver with a transmitter
US5751774A (en) * 1996-04-04 1998-05-12 Lucent Technologies Inc. Transmission system for digital audio broadcasting
US5799091A (en) * 1996-05-24 1998-08-25 Lsi Logic Corporation Single chip solution for multimedia GSM mobile station systems
US5953323A (en) * 1996-08-30 1999-09-14 Telefonaktiebolaget L M Ericsson (Publ) Method and apparatus for adapting non-cellular private radio systems to be compatible with cellular mobile phones
FI974153A (fi) * 1997-11-06 1999-05-07 Nokia Mobile Phones Ltd Menetelmä ja järjestely matkaviestimen sijainnin määrittelemiseksi
EP0939527B1 (fr) * 1998-02-18 2007-12-05 Sony Deutschland GmbH Application de signaux multiporteurs dans des intervalles temporels d'un système GSM
US6320919B1 (en) * 1998-11-30 2001-11-20 Ericsson Inc. Adaptive channel characterization using decoded symbols
US6327469B1 (en) * 1998-12-11 2001-12-04 Motorola, Inc. Channel scanning method and apparatus
GB2347286B (en) * 1999-02-26 2001-04-18 Motorola Ltd Frequency tracking loop and method of frequency tracking
GB2347831B (en) * 1999-03-06 2004-07-07 Nec Technologies Sychronisation in digital data transmission systems
DE29905942U1 (de) * 1999-04-01 1999-09-16 IAD Gesellschaft für Informatik, Automatisierung und Datenverarbeitung mbH, 90613 Großhabersdorf Vorrichtung zur Rahmensynchronisation eines Übertragungssignals
ES2262266T3 (es) * 1999-04-23 2006-11-16 Sony Deutschland Gmbh Preambulo de sincronicacion en un sistema ofdm.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0215065A2 *

Also Published As

Publication number Publication date
CN1471770A (zh) 2004-01-28
WO2002015065A2 (fr) 2002-02-21
US7346138B2 (en) 2008-03-18
DE10040222A1 (de) 2002-02-28
CN1305249C (zh) 2007-03-14
US20040170239A1 (en) 2004-09-02
WO2002015065A3 (fr) 2003-08-28

Similar Documents

Publication Publication Date Title
DE60120110T2 (de) Kommunikationsvorrichtung
DE69429300T2 (de) Phasenkorrektion für einen Funkempfänger auf der Basis einer Trainingsfolge
EP0196723B1 (fr) Méthode et circuit pour la synchronisation des dispositifs de réception dans un système de transmission multiplex numérique
DE60027432T2 (de) Synchronisierung sowie erfassung der modulationsart
DE69630759T2 (de) Mobilstationsortungsverfahren und System und Mobilstation dafür
DE69128673T2 (de) Verfahren und Einrichtung zur Verarbeitung eines empfangenen Funkdatensignals
WO2000067405A1 (fr) Procede pour former et pour determiner une sequence de synchronisation, procede de synchronisation, unite d'emission et unite de reception
DE69533687T2 (de) Verfahren und Vorrichtung zur Messung der Impulsantwort eines Funkkanals
EP1027788B1 (fr) Procede et dispositif de transfert de donnees par une interface radio dans un systeme de radiocommunications
DE69836097T2 (de) Verfahren und vorrichtung für sende-diversity durch umschaltbare antennen
EP1058974B1 (fr) Procede et systeme de radiocommunications pour transmettre des informations entre une station de base et d'autres stations
EP2524442A1 (fr) Procédé et dispositif de transfert sans fil de paquets de données
EP0990320B1 (fr) Procede de synchronisation de frequence pour une station mobile dans un systeme de radiocommunication
EP1356406A2 (fr) Procede permettant de faire fonctionner un recepteur de messages
EP0990319B1 (fr) Procede de synchronisation temporelle pour une station mobile dans un systeme de radiocommunication
DE10001491A1 (de) Verfahren und Vorrichtung zur Synchronisation von Datenübertragungseinrichtungen
EP0534399B1 (fr) Procédé de multiplexage temporel pour déterminer la variation de phase d'un signal de réception
DE69329593T2 (de) Verfahren zur Kompensation von Mehrwegeausbreitung
EP1166468A1 (fr) Procede de synchronisation pour stations de base
DE19826036C2 (de) Verfahren zur Trennung von mehreren überlagerten codierten Nutzersignalen
WO2000052846A2 (fr) Procede de regulation de la puissance de transmission de stations radio dans un systeme de radiocommunication cdma
DE19955357C2 (de) Verfahren zur Signalübertragung in einem Funk-Kommunikationssystem und Teilnehmerstation
DE19907502C2 (de) Verfahren zur Kanalschätzung
DE19914324C1 (de) Kommunikationssystem zur Datenübertragung in einem vermaschten Netzwerk unter Verwendung eines Verfahrens mit Muliträgerübertragung
WO1999020011A1 (fr) Procede et station radio pour transmettre des donnees

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20030312

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Extension state: AL LT LV MK RO SI

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: ERICSSON AB

17Q First examination report despatched

Effective date: 20090122

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20090804