Terminal unit for digital mobile radiotelephone communication and method for evaluating data received in a terminal unit of this type

Translation of description of equivalent WO 9848521 A2

Terminal for digital mobile radio and

Method for evaluating received data terminal in such a

The present invention relates to a terminal for digital mobile radio according to the preamble of the accompanying _Anspruches l and a method for evaluating data received in a terminal for digital mobile radio.

In digital mobile radio are usually time division multiple access

Method for transmitting the data. The existing on a signal transmitted between base stations and mobile stations support signal bandwidth is shared in time between the various participants. Often, time-division multiplexing and frequency division multiplexing are combined such that there are multiple carrier frequencies is then accessed in each case separately according to the time-division multiplex method. Thus, for. Example, in the GSM system (GSM) carrier frequencies with 200 KHz separation distance to each other, which are in turn divided into eight time slots or data packets. In this case, the mobile stations from the base stations are often transmitted data that are important for only one or none of the mobile stations. This can conversely also relate to data packets that are sent from a mobile station to a base station. Unimportant data packets can hereby be data packets that contain so-called blank or dummy data, but it can also be data packets that contain information that does not relate to the receiving terminal or not more concern because the terminal has received them z. B. ever , thereby all data transmitted from the receiving terminal is received in the prior art and processed regardless of whether the data is needed by the terminal or not. This has an increased power consumption in the terminal result, which is particularly disadvantageous in battery or battery-powered mobile stations. The _AASK to the present invention is thus a terminal for digital mobile radio according to the preamble _dit _beigefügten claim 1 and a method for evaluating data received in a terminal for digital

provide mobile, in which a reduction in power consumption is guaranteed upon receipt of unimportant information.

This object is achieved by a terminal for digital

Mobile achieved with the features of appended claim 1 and a method for evaluating received in a terminal for digital mobile radio data having the features of appended claim 12th

The terminal device according to the invention for digital mobile radio comprising a receiving means for receiving digital data packets, and is characterized by a decision means, on the one consisting of one or more data packets prior to complete reception

Information unit on the basis of already received part of the information unit decides whether the information unit is or is not important, and in a decision that the information unit is unimportant, the receiving unit to ignore the rest of the

Information unit causes. In the terminal according to the invention The process of the invention for evaluation of received data is realized according to claim 12, comprising the steps of: receiving digital data packets, deciding on the basis of an already received part of an information unit prior to complete reception of the information unit, whether the information unit is important or not, and ignoring the rest of the information unit, when the information unit is unimportant. _Gnder the present invention is therefore not to wait until a piece of information has been completely received, but it is already evaluated early due to an already received part of an information unit, whether the transmitted information unit for that terminal is important or not. If the information unit for that terminal unimportant, so the reception of the rest of the information unit is canceled. The rest of detected as unimportant information unit does not receive more and are subsequently processed, which means a considerable reduction in power consumption is achieved in the terminal thus. The terminal device according to the invention can be a base station or a mobile station. Especially with a battery or battery-operating mobile station is enabled by the present invention reduced power consumption is of great importance.

Furthermore, the present invention is independent of the system in which the data transfer takes place. To the

For example, the present invention also in the GSM system such as the DECT system (Digital European Cordless Telephone) applicable where the two systems, the transmission of the digital data in time-division multiplex method is performed. The transmission of the data in the time-division multiplex method is carried out in so called time slots, each containing a data packet. In the GSM system, each time frame includes eight time slots or data packets, while in each case per frame twelve time slots or data packets are provided for transmitting and receiving in the DECT system.

The present invention makes it possible to ignore data packets from one or more existing units of information already upon receipt of a part of the information unit, when the information unit is recognized as important. In this case, accordingly, after the reception of a data packet or a portion of a data packet decided whether the associated information unit is or is not important.

In the GSM system, for. Example, a signaling channel or a signaling data containing other words

Information unit is provided which every 0.5 to 2 s is transmitted to the mobile stations from a base station. The signaling information unit is distributed over four time slots, wherein each one time slot is transferred to one of four successive time frames, that the time is transmitted in separate blocks in ormationseinheit. After receiving the first of the four data packets can be avoided by means of the present invention, the reception, and thus the processing of the remaining three data packets when the information unit is detected on the basis of the first received data packet as unimportant.

Does not matter for the purposes of the present invention are all pieces of information that contain data for the receiving terminal of no significance or not of this or no longer needed. This can eg. As his dummy data or padding data containing pieces of information that are always emitted for example from a mobile station, when no connection is to mediate and thus no data in the signaling channel to be transmitted. Furthermore, it may be unimportant in information units to data that has been received from the receiving terminal before, but will not be needed again. Another possibility for unimportant information units are data that do not relate to the receiving terminal, but other terminals.

Advantageous embodiments of the present invention are given in the subclaims 2 to 11 and 13 to the 22nd _Vorteilhafterweise thereby consisting of the soft decision values ​​of the already received part of the in the decision as to whether the information unit is or is not important, is made based on a probability value,_formationseinheit is calculated. Soft decision values ​​of a_digitalen signal provided by an equalizer in the receiving unit of terminal equipment available and contain information about the statistical reliability of the transmitted digital value. In other words, the soft decision value of a received digital signal is a probability value of whether the digital signal is transmitted properly. According to the invention, a probability value is thus by means of the soft decision values ​​of the already received part of the information unit, which are a measure of the accuracy of the received data, calculates. This probability value is used as basis for the decision whether the information unit is identified as unimportant or not. Accordingly, when a sufficiently high probability ensure that the information unit is unimportant, it is decided that the rest of the

Information unit is to be ignored. As it were calculated from the quality information on the already received part of a probability that the information unit is unimportant.

Furthermore, the terminal according to the invention in the GSM system is preferably operated or the inventive method relates to a run in the GSM system terminal. The information unit is transmitted in a transmission channel for signaling data, wherein unimportant

Information data fill data or in the terminal are not or no longer required signaling data.

In a first preferred embodiment of the present invention, the decision as to whether the information unit is or is not important, by the evaluation of the information content of the already received part of the _Informationseinheit and by comparing this In_formationsgehaltes hit with data stored in a storage device of the terminal information. It can_dabei each specific parts such. as bits of information unit are considered, their

Information content is fixed and z. B. specified the length of the information unit or the format of the information unit.

The first embodiment of the present invention is particularly suitable in which the transmitted data are coded with a coding method, wherein the useful bits as example. The signaling only a certain, relatively narrowly localized part of the insgesamten transmitted coded bit in such cases influence. An example is that used in the GSM system convolutional code, in which a useful bit influenced about eight coded bits.

In a second advantageous embodiment of the present invention, the already received part of the

Information unit with data stored in a storage device of information Endgeräteε compared in order to decide whether the information unit is or is not important. Unlike the first preferred embodiment is performed here, no evaluation of the already received part of its information content. In the storage unit according to the second embodiment can be stored, for example, the corresponding part of an expected unimportant information unit. Such unimportant information unit can z. B. consist of filler data. Typically, the light emitted from a particular base station fill data of a frame are always the same, so that unimportant by comparison of the already received part of the information unit with the corresponding stored part of the expected

Information unit a decision can be made. _Dhese second embodiment is particularly suitable in those cases in which the transmitted data with a _KO_dierungsverfahren are encoded in the affect the useful bits a very wide range of the transmitted coded bits. An example is that used in the GSM system Fire code, in which a useful bit affects up to 80 coded bits. The second aspect presupposes, however, that the expected unimportant information unit from the outset fully known, that is fully specified.

In a third advantageous embodiment of the present invention, therefore, a part of a previously received information unit is stored in a temporary storage means of the terminal and compared with the received part of a current information unit, to decide whether the current information unit is or is not important. Therefore, if an expected unimportant information unit or parts of it are not known or specified, a vorempfangene

Information unit or a part of it is temporarily stored. The previously received information unit can z. B. to complete reception and completely decoded in the terminal judged to be unimportant or have been detected, or they may have become unimportant in retrospect. This can repetitions of already received information units relate that no longer requires the terminal, such. As already received and evaluated signaling data. For example, in GSM systems by the base stations inquiries to establish the connection (paging requests)^" more often than only sent one time to ensure a higher probability of accessibility. Has a mobile station already received and evaluated such a request, the relevant information can be stored in the temporary memory to avoid the repeated reception of the same data. In e iner fourth preferred embodiment of the present invention, the already received part of the In_formationseinheit information about whether the information unit is or is not important, and the terminal evaluates this information to the corresponding

To make a decision. For example, the already received part of the information unit contains information about whether the information unit dummy data or user data such. B. contains signaling data. In GSM system a signaling channel other than the FACCH channel for preferably the so-called stealing flags any use, which account for two bits per data packet. This can be, for. Example, the CCCH (Common Control Channel). This can be decided in this embodiment, after detection of Stealing Flags whether the information unit is or is not important, and the receiver can be turned off during the transfer of the remainder of the data packet.

The present invention is explained in more detail by means of preferred embodiments with reference to the accompanying drawing in which the only figure 1 showing the construction of a terminal for digital mobile radio according to the invention.

As shown in FIG. 1, an inventive device for digital mobile radio includes a receiving unit 1 and a decision unit 2, which are followed by a de- interleaver 3 and channel decoder. 4 The elements shown are in the receiving unit^" of

arranged terminal, said terminal course contains additional elements for processing the received data and a transmission unit, etc., but for the present invention have no special significance.

The transmitting device, from which the terminal receives data corresponding includes, among others, a channel encoder, a Interleaver and transmitting means. The transmitter may be a base station, for. Example, while the invention_endgerät z. B. may be a mobile station. The terminal may also be a base station, while the transmitting unit is a mobile station. In the channel encoder data to be transmitted are encoded for example by a block or a convolution code, while received in the terminal coded data are decoded accordingly in the local channel decoder. 4 In the transmitter interleaver done a reordering and temporal spread of the data to be transmitted to possibly errors that may appear to be distributed randomly in the data, since most block or convolutional can suppress only statistically independent individual errors. In deinterleaver 3 of the receiving terminal the amounts shall

Restoring order of the received data.

The transmitting unit transmits the data in time-division multiplex method, ie, the data is transmitted in each case in time frames which are divided into a certain number of time slots. Each time slot comprises a corresponding data packet. In general, the transfer of data takes place on a plurality of carrier frequencies, will then be accessed separately for the time-division multiplex method, so that the transmission takes place by a combination of time division multiplexing and frequency division multiplexing. The receiving device shown in FIG. 1 l thus receives information units consisting of one or more data packets Pl, P2 ... Pm ... Pz. Each data packet Pl, P2 ... Pz is transmitted in an assigned time slot. The decider 2 decides prior to full receipt of one or more data packets Pl, P2 ... Pz existing information unit on the basis of already received part of the information unit, whether the information unit is or is not important. In a decision that the information unit is unimportant, received the Decision means 2, the receiving unit 1, a signal to ignore the rest of the information unit. The_empfangseinheit 1 then stop receiving the In_formationseinheit from. Depending on the structure and the information content of the data of the entity or by_deren error rate, the receiving unit 1 the decision o_b the information unit is important or not, take after receiving multiple data packets Pl, P2 ... Pm, after receiving a single data packet Pl or after the receipt of a portion of the first data packet Pl. Decides the decision means 2 that the information unit is unimportant, it shall provide the receiving unit 1 a signal to ignore the rest of the information unit, ie z. B. the remainder of the first data packet Pl and the remaining not yet received data packets Pn ... Pz , The signal to ignore the rest of the information unit, for example, control a switch or a gate, which switches off, disabled or placed in a standby state, the receiving unit.

A multiple data packets information unit is transmitted for. Example, as the signaling data in the GSM system in a plurality of successive time frames. In each case a data packet per time frame to the terminal is transmitted. The terminal device according to the invention can already decide, after reception of the first data packet, whether the information unit is or is not important. This is especially possible if the transmitted data is a redundant encoding have been subjected, thereby doubling the data bits of the information unit^" is achieved. Since the first data packet in this case the double number of data bits, so that a relatively reliable 'statement can be made already after the reception of the first data packet, whether the entire information unit is or is not important. Kicking on the transmission channel between the transmitter and the receiving terminal transmission errors occur, additional data must receive who_ds in order to make a reliable decision. Appears to be transmitted signaling data, for example, four data packets, then from a certain error rate no longer be decided on the basis of a single data packet, o_b the signaling data are important or not, but it must also be the second data packet is received in order to enable a reliable statement.

The receiving device 1 includes an equalizer that provides the soft decision values ​​of the received digital data. The soft decision values ​​provide quality information on the received digital data, that is, they allow for an assessment of the probability that the transmitted data has been transmitted correctly or are faulty. The decision means 2 uses these soft decision values ​​of the already received part of an information unit to calculate a probability value, whether the information unit is unimportant or not. The decider 2 decides this case that the

is information unit unimportant if the probability is high enough, that is, when the calculated probability value is above a predetermined probability threshold. In this way it can be prevented that an important information unit is not detected due to the erroneous transmission of single bits, and that an unimportant information unit for the same reason is not detected.

The present invention will hereinafter with reference to preferred

Embodiments explained, while a terminal is referred to, which is operated in the GSM system and the information unit is transmitted in a transmission channel for signaling data. In ϊlieser concretization unimportant information units may be, for example, padding data, which are then sent from a base station to the mobile stations when on the signaling channel is no signaling data to be transmitted. This is, for. Example, the case when no connection is to be conveyed.

but unimportant information units can also

contain signaling data, which do not affect the terminal. A base station transmits in the GSM system on four data packets or time slots distributed signaling data, if a connection is to communicate to a mobile station. These signaling data are, however, received by all mobile stations accessible. This signaling data signaling to the concerned mobile station that a connection is to be transmitted. The transmission of the signaling data takes it about 15 ms, each mobile station every 0.5 to 2 s hinhört or is activated to check if they will be called. Normally, however, the signaling data is intended only for a single mobile station, and the other mobile stations are not affected. An unimportant information unit thus contains, for example,

Signaling data intended for another mobile station.

A further possibility for unimportant information units are data which the receiving terminal or

receiving mobile station already once, but they no longer needed. In the GSM system are the z. B. Connection requirements (paging requests) that are sent one after another to increase the probability of availability several times. The last case^"furthermore also relates to the BCCH data (Broadcast Control Channel) in which the configuration of the system of the mobile station is informed. This data is sent in up to eight user data packets and usually change extremely rare. However, the mobile station must receive the data at 30-second, in the event that the base station is reconfigured. These data are thus in to unimportant data _Sheld the present invention, when the terminal has received it once and they have not changed in the repeated transmission.

In a first preferred embodiment, the decision means comprises 2 shows a memory device having previously stored information, and an evaluation device which evaluates the already received part of the information unit to its information content and this information content is compared with the information stored in the storage device to decide whether the information unit is important or not. It can thus be such bits or relationships evaluate from the data and the stored knowledge about constant bits or correlations between individual bits already received between bits that can be seen that the information unit of the terminal is not important.

It is particularly useful to repeat to consider a certain specified portion of the data packet, in which after a specific defining a particular type of data is always arranged. Includes, for example, in the GSM system, the first byte of a signaling data information unit information about the length of the information unit, the evaluation unit evaluates this length information and compares it with data stored in the storage device permitted maximum and / or minimum length values. If the evaluated length of the information unit to short to obtain meaningful information can, or is longer than the maximum allowed length, the rest of the entity can be ignored.

Might as well the second byte of the data packet to be considered, including the message format in the GSM system. The processor then evaluates the received data with respect to the message format and compares it with data stored in the storage means _NachrichtenformatInformationen to find out whether the _Nac_Hric_Hcard format for the terminal for interest. If_dIE show the evaluated data, that the information unit includes a message that does not affect the terminal, so the rest of the information unit is ignored. furthermore_kLEVERAGING also header information of the transmitted data packet are examined, define the expected context, z. B. Layer 2 header, Protocol Descriptor, etc. An example of an implementation in the GSM system when receiving a Füllnachricht the connection request channel (Paging Message ) is given in the following, where the first two bytes represent the already received part of Füllnachricht. The known data are underlined here: CKL reserved bits for compatibility for phase

1

£ 00101-- Layer 2 length, 5 <length <22 0110 Protocol Discriminator

0000 Skip Indicator

The bits shown above are read from right to left, the two bits have been defined in the first row with the value "l" and "0" for Phase 1 of the GSM system as an encoding format, but in the phase 2 of the GSM Systems are no longer needed. To nevertheless a

To ensure compatibility between operating in Phase 1 systems and operated in phase 2 systems, these two bits are further transmitted in phase 2 of the GSM system continues in the manner shown. In the second line of the six are to presented to the two subsequent bits in the first line containing the length information of the Layer 2 length. When considering the length information in the illustrated example is a result of the underlined sixth bits of the "0^wValue to decide whether the message is important or not. This results both shown in the first line of reserved bits in common with the six shown in the second line Bits in length, the first byte of the already received part of the Füllnachricht. The NAEC shown in the third line,_Hfirst four bits of the Protocol Discriminator and serve to activate the corresponding layer in the Mo_bilstation. The features shown in the fourth line, last four bits of the second byte are in the phase 2 of the GSM_Systems not yet specified and reserved for each extensions in Phase 3 or Phase. 4 If that spews out other than the illustrated "0000" values, the incoming information unit is ignored.

As many known bits are present in the environment of Layer 2 length, the layers can be the coding used in the GSM system 2 length with a remaining uncertainty determine: The length is either 5, then the information unit can only be a Füllnachricht that from the terminal or the mobile station is ignored, or the length is 23, which is an illegal length and the mobile station ignores the information unit also. Should one or more of the bits marked here as known have another than the value shown here, the information unit of the mobile station is also recognized as invalid and ignored.

The terminal and the method of the first

Embodiment is particularly suitable for data that has been encoded with a coding method in which the useful bits affect only a certain, relatively narrowly localized part of the transmitted coded bits. One example is the Convolutional used in the GSM system code with a constraint length of about 8, ie, a user data bit affects about 8 encoded bits. If the unit of information transmitted in four data packages, so be from eight influenced coded bits two bits in the first data packet transmitted. The relationship between these two bits then allows a conclusion to all of the information unit. In a second preferred embodiment, the decision device 2 includes a memory device having previously stored information, and compares the already received part of the information unit with the information stored in the storage device to decide whether the information unit is or is not important. Unlike the first embodiment, the received data will not be evaluated in terms of their information content.

For example, in the memory unit, a data packet or an information unit with empty messages to be stored, which are always transferred in a signaling channel from a base station, if no

Signaling data to be transmitted. Where the previously received part of the information unit with the corresponding stored part of an expected information unit with dummy data match, it is assumed that the incoming information unit actually contains dummy data. The receiving unit 1 will then ignore the rest of the information unit or cancels the reception.

Depending on the encoding method must suppose that in fact an information unit with dummy data arrives, theoretically not necessarily be correct. However, if the probability that an information unit with dummy data is present, sufficiently high so the procedure is sufficiently reliable. The method according to the second embodiment is similar to the comparison of checksums, even if it is not exlizit is checksums in the compared data. The base stations of the GSM system typically send out always identical Leerdaten- data packets, so that the second embodiment can be advantageously used in this field. _Das terminal and the method according to the second _Ausführungsbeispiel are particularly suitable for data with _Kodierungsverfahren are encoded, in which the Nutzbitε the above_binfluence endured coded bits in a very large area. One example is the Fire codes used in the GSM system, in which a checksum is used with an additional option for troubleshooting, and in which a user data bit affects up to 80 coded bits. However, other checksums are used in the second embodiment. In the second embodiment, however, is a prerequisite that the information previously stored in the memory device fully known, that are fully specified.

In a third embodiment of the present invention, the decision means 2 comprises a temporary storage unit in which a part of a previously received information unit is stored, and the already received part of a current information unit with the value stored in the memory means of the previously receiving information unit compares to decide whether the current information unit is or is not important. This is particularly advantageous if parts are not fixed are or all of the information unit to be stored in the storage device from the outset. Since z. Example in the GSM system, the contents of Fülldaten- packets is not set, can in this case parts or all of the filler data already received packets are stored in the temporary storage means, so that changes in the filler data or dummy data^" z. B. can be taken into account when changing a base station. Alternatively or additionally, in the temporary storage facility also other data packets can be stored, which were previously received and not yet were unimportant, however, have become irrelevant because they in z. B.

Terminal are no longer needed to repeats of the _empfangs to avoid of already received, but no more relevant data.

_In to a fourth embodiment of the present invention _en_dthe apparatus and method according to the invention contains the _bince received part of the information unit information as to whether the information unit is or is not important. The decision means 2 thereby comprises an evaluation unit which evaluates this information. This embodiment is based on the idea to make reference to the first part of the coded bits of an information unit, the type of the information unit in the first data packet as such. Given z. B. must empty data packets and user data packets are defined sufficiently different or optionally additional, for the

Signaling to insert itself unnecessary data which are different for the Leerdaten- and user data packets that the difference can be detected on the basis of the first part of the information unit already. Alternatively, you can also attach to the corresponding spezifierten data further data already allow a distinction.

In the specific case of the GSM system following enlargement could be made. Currently, the so-called stealing flags that make up two bits per data packet, including the channel CCCH (Common Control Channel) is not used. The Stealing Flags are used exclusively in the FACCH (Fast Associated Control Channel) to distinguish between user data and signaling data, z. B. during a hand-overs. In CCCH can be set so that the base station signals from these Stealing Flags whether a payload or empty or fill data available. Detects a terminal after receiving the first data packet one or both Stealing flags, the data packet does not need to be further evaluated. This saves additionally determining the remaining bits in this Data packet. The BCCH data (Broadcast Control Channel), these bits are set if the information within the last 30 seconds has changed, so has to be re-read from all accessible terminals or mobile stations.

Does the terminal via a correspondingly fast data processing, as can already be switched off during the reception of the first data packet immediately after the detection of one or both Stealing Flags this data packet, the receiver even during the transfer of the remainder of the data packet. This is also true for the first, the second and the third embodiment, in which immediately after the detection of an already received part of a first data packet of

Information unit by means of a correspondingly high-speed data processing, the receiver can still be switched off during the transmission of the remainder of the first data packet. However, at least can be completed in all embodiments, the evaluation of the remainder of the first data packet, has once the decision means deciding the already received part of the information unit and evaluated its importance. This saves a lot of effort in the digital signal processing of the equalizer algorithm in the receiving device and reduces power consumption.