DE102005018870A1 - Method for data transmission, transmitter and receiver - Google Patents

Abstract

The invention is based on the idea of converting data to be transmitted by turbo-coding into systematic bits and parity bits. From a transmitter, a first data packet containing the systematic bits and containing a portion of the parity bits is sent to a receiver. If there is a corresponding request from the receiver, at least one retry data packet is sent to the receiver that does not contain any parity bits contained in the first data packet.

Description

The The present invention relates to a method for data transmission as well as a suitably designed transmitter and receiver. The data transfer takes place in particular according to a ARQ method or a hybrid ARQ method, in a communication system, in particular a mobile radio system.

Especially in connection with mobile radio systems is often the use of so-called Packet access method or packet-oriented data connections proposed because the emerging message types often a have very high burst factor, so only short activity periods exist that are interrupted by long breaks. packet-oriented Data connections can in this case the efficiency compared to other data transmission methods, in which a continuous data stream is present, considerably increase, as in data transfer procedures a once allocated resource with a continuous data stream, such as. a carrier frequency or a timeslot, while the entire communication relationship remains assigned, i. a Resource remains occupied even if there are no data transfers at the moment abut, so this resource does not work for other network participants to disposal stands. this leads to to a non-optimal use of the scarce frequency spectrum for mobile radio systems.

Future mobile radio systems, such as according to the UMTS mobile standard ("Universal Mobile Telecommunications System "), will offer a variety of different services, in addition to the pure voice transmission Multimedia applications become increasingly important. The accompanying Requires service diversity with different transmission rates a very flexible access protocol on the air interface in the future Mobile systems. Have packet-oriented data transmission methods proved to be very suitable here.

in the Connection with UMTS mobile radio systems became in package-oriented Data connections a so-called ARQ method ("Automatic Repeat Request ") proposed. In this case, the data packets transmitted by a transmitter to a receiver are on the receiver side checked for their quality after decoding. Is a received data packet faulty, the recipient demands a retransmission this data packet from the sender, i. it will be a repeat data packet from the transmitter to the receiver sent, which with the previously sent and received incorrectly Data packet is identical or partially identical (depending on whether the retry data packet less or as much data as the original one Contains data packet, is spoken of a full or a partial repetition). Regarding this for the UMTS mobile standard proposed ARQ method, which also termed hybrid ARQ type I method is both transmission of data as well as so-called header information in one Data packet provided, the header information also information for error checking, how for example, CRC bits ("Cyclic redundancy Check ") and can also be coded for error correction (so-called "Forward Error Correction", FEC).

In UMTS systems are used in particular for the realization of the HSDPA (High Speed Downlink Packet Access) and for the realization of the so-called EDCH (Enhanced Uplink) HARQ method used. For coding the one to be transferred Data is used in particular turbo codes, which transmit the Data or bits are converted into systematic bit and parity bit.

Becomes doing the transfer a first data packet not correctly decoded on the receiving side (detectable on the basis of the checksum), so will a retransmission requested. Upon receipt of the corresponding repeat data packet then a new decode using both data packets carried out.

If over the Air interface transmitted less bit can be must be generated as part of the coding, an appropriate subset for the first transmission (first data packet) and also for the repetition (s) (repetition data packet (s)) are selected. This selection is made by a so-called rate matching algorithm, in particular a puncturing algorithm realized, wherein the total amount of bits appropriate bits are removed (dotted), which then not transferred become.

A punctuation algorithm has already been specified for the UMTS Release 99. This algorithm removes a given number of bits from a block of bits and selects these bits as evenly as possible, ie with as even spacing as possible. When using turbo codes, it was further specified that the so-called systematic bits are not punctured and first parity bits (parity 1 (bit)) and second Paity bit (parity 2 (bit)) are each punctured separately, both parity bit streams are preferably equally punctured.

• – Es gibt Übertragungen, die systematische Bit bevorzugen. Dabei werden die Systematischen Bits nicht punktiert, die ersten und zweiten Paritätsbit werden beide gleich stark punktiert. Eine solche Übertragung wird bevorzugt für die Erstübertragung verwendet.
• – Es gibt Übertragungen, die Paritätsbit bevorzugen. Dabei werden die Paritätsbit nicht punktiert, statt dessen die systematischen Bit. Eine solche Übertragung wird bevorzugt für eine Wiederholungsübertragung verwendet. Dadurch soll erreicht werden, dass bei der Wiederholungsübertragung die Paritätsbit, welche ja bei der Erstübertragung teils punktiert wurden, nun möglichst vollständig übertragen werden. Stehen für die Wiederholungsübertragung, also im Wiederholungsdatenpaket, nicht so viele Bitstellen zur Verfügung, dass alle Paritätsbit übertragen werden können, so werden im Widerholungsdatenpaket überhaupt keine systematischen Bit übertragen und die ersten und zweiten Paritätsbit werden beide gleich stark punktiert.

An important problem to be solved by the rate matching algorithm used is to make an appropriate choice of bits for puncturing for the first transmission and for the repeat transmission (s). The problem arises in particular when a relatively high number of bits must be punctured, especially if at least 1/2 of the bit must be punctured. This was already evident in the introduction of HSDPA. The following was determined:

• - There are transfers that prefer systematic bits. The systematic bits are not punctured, the first and second parity bits are both equally punctured. Such a transmission is preferably used for the first transmission.
• - There are transfers that prefer parity bits. The parity bits are not punctured, instead the systematic bits are punctured. Such a transmission is preferably used for a retransmission. This is intended to ensure that in the retransmission, the parity bits, which were partially dotted during the initial transmission, are now transmitted as completely as possible. If there are not so many bit locations available for the retransmission, ie in the repetition data packet, that all parity bits can be transmitted, then no systematic bits are transmitted in the repeat data packet and the first and second parity bits are both equally punctured.

The individual to be transferred Bit or the bit to be punctured by a defined Rate matching algorithm (Ratematchingalgorithmus) selected.

Here a quote from the Ratematching algorithm from 3GPP TS 25.212 V6.3.0 (2004-12), Chapter 4.2.7.5 Rate matching pattern determination (Nur the for Puncturing relevant portion is shown).

Label the bits before rate matching with:
x _i1 , x _i2 , x _i3 , ... x _iX , where I is the TrCH (traffic channel) number and the sequence in 4.2.7.3 is defined for the uplink and 4.2.7.4 for the downlink. The parameters X _i , e _ini , e _plus , and e _minus are given in 4.2.7.1 for the uplink and in 4.2.7.2 for the downlink.

The rate adjustment procedure is carried out according to the following regulation:

The parameters e _plus , e _minus and X _i are set slightly differently for the first and second parity bits in order to achieve different puncturing patterns here as well. Also for different transfers, the puncturing pattern can be varied by varying the parameter to avoid making identical transfers. A variation of one shifts the puncturing pattern; this is controlled by the parameter r.

The definition of these parameters for the case of EDCH (E-DCH) is contained in the specification in the chapters of 3GPP TS 25.212 V6.3.0 (2004-12) cited below:
"4.9.2.2 Information field mapping of retransmission sequence number"
"4.8.4.3 HARQ Rate Matching Stage"
"4.5.4.3 HARQ Second Rate Matching Stage"

in the This rate adaptation will be briefly explained again below, wherein the presentation is limited to a range in which 1/3 to 1/2 of Bits are dotted.

In 4.9.2.2 it is determined that for the first transmission the E-DCH RV (redundancy version) index "0" used will, and for the first retransmission the E-DCH RV index "3" is used.

In 4.8.4.3 it is specified that the first transmission of the E-DCH RV index "0" is the parameter s = 1 and r = 0 are used. s = 1 means that the systematic bits are preferred. Furthermore, it is determined that the E-DCH RV Index "3" of the retransmission the parameters s = 0 and r = 1 are used. s = 0 means that the parity bits are preferred.

Chapter 4.5.4.3 defines how to calculate the parameters e _plus , e _minus and X _i for the systematic bits, the parity 1 bit (first parity bit) and the parity 2 bit (second parity bit) for the rate matching algorithm. The rate matching algorithm itself is then described in chapter 4.2.7.5 (see above).

This algorithm is shown in pseudo-code. A bit is punctured by assigning it the value delta, since in a following step all bits with the value delta are removed. Translated into German and presented more comprehensively, the algorithm can also be represented as follows:

Elaborate of The underlying analysis showed the following: The presented Method according to the state The technique works satisfactorily when the coding rate is at most 1/2, i. if at most a third of the coded bits is punctured. In this case, at the retransmission transmit all parity bit which, of course, makes it is ensured that in the subsequent decoding all Bit available stand: The systematic bits are completely from the first transfer to available the parity bit completely from the retransmission, from the other transmission are partially bit also in addition, redundant available. The fact that all coded bits are available, the full Coding rate of the turbo-code reached, this can be also an optimal performance reach the code.

However, if the coding rate is in the range between 2/3 and 1/2, which is the case when puncturing between 1/2 and 1/3 of the bits, then the prior art approach is disadvantageous or not for the following reasons optimal:
In this case, between 1/4 and 1/2 of the parity bits are transmitted during the first transmission. In the retransmission, more parity bits can be transmitted, in this case between 3/4 and all. In either case, a larger number of parity bits are transmitted in first transmission and retransmission together than are present after the encoding. It would be theoretically possible to transfer all parity bits at least once. However, this is not achieved by the given prior art algorithm.

The reason for not transmitting individual parity bits lies in the uniform selection of parity bits according to the prior art rate matching algorithm. This is briefly explained by the following example: It is assumed that there are 20 systematic and 20 parity 1 and parity 2 bits each after coding; During the first transmission, in addition to the 20 systematic bits, 7 parityl bits and 7 parity 2 bits are transmitted. In total, 20 + 2 · 7 = 34 bits are transmitted. The Ratematching algorithm selects these bits as evenly as possible. This selection is shown in the following table. In the table, the first column indicates the value of the loop variable m of the rate matching algorithm. In the second column, the value of the error variable e at the time of the if query is plotted (the value 20 in the line denoted by ini corresponds to the initial value of e, ie e _ini ). In the third column, the bits are selected, which are selected by the Ratematchingalgorithmus. In this case, the algorithm chooses the distances between the parity bits to 3, 3, 2, 3,3,3 (the last 3 corresponds to the distance with wrap around from m = 19 to m = 2).

In Columns 4 (e) and 5 (bits) are the values of e and the selected bits for the 2nd transmission (column heading "2.") in the same way, as for the first transmission wear. At the 2nd transmission (the retransmission) 17 parityl and parity2 bits are transmitted each, in total there are again 2 · 17 = 34 bits; the same number as in the first transmission. This is important, because then the same formats for the transfer can be used. The rate matching algorithm chooses the not transferred Bit also equally, namely at a distance of 7, 6, 7 (last distance again wrap around of m = 20 to m = 7).

Column 6 (1 + 2) lists the bits transmitted in either the first or second transmission (first data packet or repeat data packet). As you can see, in this case, this column is identical to the 5th column, ie the first transfer could not stuff any "holes" in the second transfer, which is the least favorable case, you could try changing the starting value for e _In this way, one could achieve that at least some of the bits transmitted during the first transmission encounter gaps in the second transmission, but one can not achieve this in the first _{instance by} shifting the pattern (puncturing pattern) for the second (or the first) transmission the gap between gaps in the second transmission is 7 or 6, that between transmitted bits of the first transmission but 3, 3, 2, 3, 3, 3 Distance of 6 is achievable by the combination of two distances of length 3, but a distance of 7 is not achievable (reachable are 3 + 3 = 6, 2 + 3 + 3 = Even with any shift of the puncturing pattern, it can not be achieved that both non-transmitted bits of the second transmission are transmitted during the first transmission. Thus, according to the prior art, in each case after the second transmission, there is at least one bit which has not been transmitted in any transmission.

Of the The invention is based on the object of specifying a technical teaching, which is a reliable one and preferably simple transmission of data.

Especially The invention is based on the object, a technical teaching specify a simple and reliable transmission of data according to a ARQ method allows Turbo coding at a rate between 2/3 and 3/4 (under consideration rate matching) and / or a rate matching method with a puncture rate between 1/2 and 5/9.

These Task is solved by the characteristics of the independent Claims. Advantageous and expedient developments are the dependent claims refer to. In the context of the invention are also developments the independent one Device claims, the dependent claims correspond to the method claim.

The Invention is based first on the knowledge that it is state of the art, in particular also at a puncture rate between 1/2 and 5/9, is not always possible all parity bits at least once.

One The further step of the invention lies in recognizing that, in particular in the mentioned range of the puncturing rate, a transmission of all parity bits after all possible is. If need be but three transfers be combined.

Elaborate investigations then showed that, especially in the mentioned range of puncturing rates, a transmission all parity bits then possible is when a first data packet contains the systematic bits and one Part of the parity bit contains and a retry data packet does not contain any parity bits in the first data packet are included.

Possibly. especially with coding rates over 2/3, a third has to be transmitted to transfer all data packets Data packet are used, which preferably contains systematic bit as well as the first data packet.

Further showed the elaborate The invention based simulations that, in particular at Using a rate matching algorithm to select in one Data contained in the packet, in particular in said range of Puncturing rate, a transmission all parity bits then possible when the retry data packet contains no parity bits, the contained in the first data packet.

The means that in the repetition data packet no parity bits are transmitted repeatedly if there is room in the replay data package. Because through this surprising Instruction can be achieved that, especially when using a rate matching algorithm for selecting in a data packet contained bit, for transmission in the retry data packet only such parity bits are selected not already for transmission selected in the first data packet.

The Thus, the invention is finally based on the idea, in particular a certain amount to be transferred Convert data into systematic bit and parity bit by turbo coding. A sender sends a first data packet to a receiver which contains the systematic bits and contains a part of the parity bit. at There is a corresponding request from the recipient at least one repeat data packet sent to the receiver, that no parity bit contains which are contained in the first data packet.

It It is also within the scope of the invention that the parity bit only consists of a certain group of parity bits, besides the others parity may be the result of turbo coding, which then also together with the specific group of parity bits or separately from the specific group of parity bits be subjected to a bit rate adjustment.

Preferably contains a first iteration packet contains the parity bits that are neither in the first Data packet still contained in another repeat data packet are.

Of the Term "more Repeat Data Packages " not a repeated first data packet and a repeated one first repeat data packet. Because a repeated first Data packet and a repeated first repeat data packet then sent repeatedly, albeit after sending all the retry data packets the transfer not yet successful.

Preferably contains the first repeating data packet next to parity bits in the first data packet not included, systematic bit. This can be systematic Bit transmitted repeatedly which means reliability the transmission elevated becomes.

• a) Setzen der Fehlervariablen auf den Initialwert
• b) Setzen des Bitindex auf das erste Bit
• c) Subtraktion des Erniedrigungswertes der Fehlervariablen von der Fehlervariablen.
• d) Falls die Fehlervariable kleiner oder gleich 0 ist durchführen der Schritte e) bis f)
• e) Punktieren des durch den Bitindex angezeigten Bit
• f) Addition des Erhöhungs-Wert zur Fehlervariablen
• g) Erhöhen des Bitindex
• h) wiederholen der Schritte c) bis g), bis der Bitindex die Anzahl der zu verarbeitenden Bit überschreitet.

If all parity bits in the first data packet or in the retry data packet are transmitted exactly once, this results in a particularly reliable transmission of the data. Likewise, when all the parity bits in the first data packet or in the first repeating data packet or in the second repeating data packet are transmitted exactly once, it is achieved in the context of the invention, in particular when using the following rate matching algorithm for selecting the bits contained in a first data packet and / or repetition data packet Parity bit in the first data packet or in the retry data packet and possibly in the second retry data packet are transmitted exactly once. The (bit) rate matching algorithm contains the following method steps:

• a) Setting the error variable to the initial value
• b) Setting the bit index to the first bit
• c) Subtracting the decrement value of the error variable from the error variable.
• d) If the error variable is less than or equal to 0, perform steps e) to f)
• e) puncturing the bit indicated by the bit index
• f) Addition of the increase value to the error variable
• g) increasing the bit index
• h) repeating steps c) to g) until the bit index exceeds the number of bits to be processed.

These Process steps lead to the same result as the execution of the following process steps or the following rate matching algorithm, its use alternatively stands for the rate matching algorithm just mentioned, and therefore also within the scope of the invention.

e_ini

den Initialwert der Fehlervariablen

e

den aktuellen Wert der Fehlervariablen

e_minus

den Erniedrigungs-Wert der Fehlervariablen

e_plus

den Erhöhungs-Wert der Fehlervariablen

X_i

die Anzahl der zu verarbeitenden Bit

m

den Schleifenindex

x_i,m

das Bit Nummer m

δ

die Bezeichnung für ein punktiertes d.h. entferntes Bit

Where:

e _ini

the initial value of the error variable

e

the current value of the error variable

e _minus

the decrement value of the error variable

e _plus

the increase value of the error variable

X _i

the number of bits to be processed

m

the loop index

x _{i, m}

the bit number m

δ

the name for a dotted, ie remote, bit

Preferably Thus, in the context of the invention, the same rate matching algorithm is used used in a UMTS system for others Purposes already used anyway. This allows the rate matching algorithm be implemented with less effort.

Preferably, the initial value e _ini (r) for the error variable of the rate matching algorithm is chosen such that the first repeat data packet does not contain any parity bits contained in the first data packet, and preferably contains those parity bits that are contained neither in the first data packet nor in another repetition data packet ,

For the use of the rate matching algorithm for selecting the parity bit contained or to be transmitted in the first data packet or second repeat data packet, the following preferably applies: e ini (r) = {X i - ·r · e plus / r Max ⌋ - 1) mod e plus } + 1, In which the following applies to the use of the rate matching algorithm for selecting the parity bits in the first repeat data packet: e ini (r) = {(2X i + 1 - ⌈ (r + 1) · e plus / r Max ⌉)Fashion plus } + 1, where:
e _ini (r) = the initial value for the error variable;
r = 0 if the rate matching algorithm is applied in conjunction with the first data packet;
r = 1 if the rate matching algorithm is applied in conjunction with the first or second repeat data packet;
rmax = 2.

The following extensive investigations have shown that, in particular for the specified choice of the initial value for the error variable e _ini for the rate adaptation in the case of the first data packet and / or the first repetition data packet all parity bits are transmitted in total once:
The description begins with a treatment of the case that the coding rate is between ½ and 2/3, later, the case is also considered that the coding rate is between 2/3 and 3/4.

Especially It is an object of the present invention, a technical To provide teaching for many cases ensures that all parity bits (parity bits) are transmitted, i. each Bit is played at least once in the first transmission (in the first data packet) or the second transfer (in the repeat data packet). This goal is achieved by taking less than the maximum possible number from parity bit in the second transmission (in the repeat data packet) (see above). In this case, the number of transmitted in the second transmission Bit and the shift of the puncturing pattern so cleverly chosen that every parity bit exactly once, either in the first transfer or the second transmission becomes.

for Derivation of the optimal procedure is the well-known Ratematchingalgorithmus - in something another form - still once considered:

Algorithm for first transmission analysis, called A1:

• statt e mit e₁ und e₂
• statt e_ini mit e_ini1 und e_ini2
• statt e_minus mit e_minus1 Und e_minus2
• statt e_plus mit e_plus1 und e_plus2

For notation, another index is introduced which distinguishes between first and second transmission, ie between A1 and A2. The variables are each denoted by:

• instead of e with e ₁ and e ₂
• instead of e _ini with e _ini1 and e _ini2
• instead of e _minus with e _minus1 and e _minus2
• instead of e _plus with e _plus1 and e _plus2

in this connection the decrementation of e is not done at the beginning of the loop, but for the first loop pass in the initialization and for the others Loop Count in the if or else branch of the previous loop pass. These We use rewording of the rate matching algorithm for the analysis the first transmission. (It should be mentioned here, that for an implementation of course uses any variant of the implementation of the algorithm can be, we consider special variants easier here the optimal parameters for both transmissions to apply.)

For the analysis the second transmission formulate the algorithm a bit more by using the swap the if and else branch, thereby achieving the condition e <= 0 vice versa becomes e> = 1. This are mutually inverse conditions, i. the second is just then Fulfills, if the first is not fulfilled and vice versa.

Algorithm for analysis of the second transmission, called A2:

aim is to achieve that at every bit, so for all m, then at A2 the bit used or transmitted becomes when is punctured at A1, and vice versa.

Both algorithms A1 and A2 should therefore both run into the if branch or both into the else branch for a given m. This can be realized if, for each iteration, ie for every m: e 2 = 1 - e 1

For then the condition from A2, namely e ₂ > = 1, is equivalent to 1 - e ₁ > = 1, because it follows that: - e ₁ > = 0 and e ₁ <= 0 that is synonymous with the condition in A1.

The equality e ₂ = 1 - e ₁ is given if, firstly, this applies to the initial value when entering the loop, and, secondly, if the update operations in the two loops in the If and Else branches are corresponding.
"first" means:
e ₂ = 1 - e ₁ at the loop _entrance , After inserting the dependence of e _ini1 and e _ini2 one obtains: e ini2 - e MINUS2 = 1 - e INI1 - e minus 1 "second" means that the changes of e in both the if branch and the else branch must be the same: + e plus1 - e minus 1 = - e MINUS2 and - e minus 1 = + e plus1 - e MINUS2

By substituting the definitions of e _minus and e _plus from the citation of the specification, one can verify that this is the case when, in the second transmission, the difference is the number of parity bits present minus the parity bits transmitted in the first transmission , This equation should apply to parity 1 bits and parity 2 bits. Thus, the core of the invention, namely to send exactly as many parity bits in the second transmission as were missing in the first transmission, is also derived via the rate matching algorithm.

So that both puncturing patterns interlock, the first condition should also be satisfied, namely e ini2 - e MINUS2 = 1 - e INI1 - e minus 1

For this there are many solutions, for each given e _ini1 one can determine a suitable e _ini2 . It is, for practical reasons, advantageous to maintain the definition of e _ini1 since this definition has already _yielded good results in many simulations (but of course the other solutions are also included in the invention). Then one can calculate that for e _ini2 : e ini2 (r) = {(X i - ⌈ (r + 1) · e plus / r Max ⌉)Fashion plus } + 1

It has already been taken into account that the parameter r is set to r = 0 for the first transmission, but to r = 1 for the second transmission, and that the transmission was specified for the first transmission e INI1 (r) = {(X i - ·r · e plus / r Max ⌋ - 1) mod e plus } + 1

With this choice of the number of parity bits and this choice of e _ini for the second transmission, one can achieve that the patterns interact optimally.

This is in the above table in columns 7 and 8 (both overwritten with 2 opt.). Again, the value of e is dependent of m and the selected Bits are shown. In the last column (1 + 2 opt) are the Bit listed, which are now sent either in the first or second transmission. As you can see now actually transmit every bit. At the second transmission exactly those bits are transmitted, which in the first transmission not transferred were. This will significantly improve the transmission characteristics reached.

Surprisingly, with the use of an algorithm already used for other purposes, it is possible with the invention to achieve a significant improvement in the transmission characteristics if the parameters for calculating the number of parity 1 and parity 2 bit and the calculation of e _{ini are} adapted only during the retransmission , The formulas for this are no more complex than the formulas according to the prior art.

Preferably, fewer parity bits are transmitted in the second transmission than provided in the prior art. The remaining bits are then preferably filled with systematic bits. This has another advantage:
If a receiver does not receive the first transmission completely for any reason, eg because an associated signaling information could not be received correctly, it will only receive the second transmission. Since this second transmission now contains more systematic bits than provided by the prior art, it is easier to decode, which in turn improves the system properties. Furthermore, there is also better information about the systematic bits in the detection of the first and second transmission, since some of these are now transmitted twice (in the first and second transmission). This, too, improves the performance, ie the probability of decoding, as shown in the investigation of HSDPA. In HSDPA, an improvement in quality was produced by so-called SMP (Signal Mapping Priority), in which systematic bits were mapped and, in contrast to parity bits, on modulation symbols having a better decoding property, thereby improving the reception quality of the systematic bits and thereby achieved better decoding property. However, this method is only applicable for higher modulations (eg 16 QAM), and therefore not applicable to E-DCH. Optimized puncturing during retransmission, however, provides a similar effect so that a similar improvement in system performance can be achieved.

These Explanations the elaborate - the invention underlying investigations and considerations should only be the background of the complex invention and its Embodiments illuminate, but the invention in no way to certain restrict preferred embodiments.

Preferably become the puncturing patterns for the case of the first data packet and the case of the retry data packet nested together.

Preferably becomes the method according to the invention for data transmission in the context of a hybrid ARQ procedure for the realization of the HSDPA or EDCH (E-DCH).

As already explained several times, the parity bit contained in a data packet or repetition data packet according to a preferred embodiment of the invention by a rate matching al selected from the turbo-coding resulting parity bit. If certain bits are selected from a set of bits by the rate matching algorithm because all bits are not transferred from the set of bits or are contained in a data packet, then the rate matching algorithm acts as a puncturing algorithm. The punctured by the puncturing algorithm bit are not transmitted and are not included in the corresponding data packet. The remaining bits are contained in the corresponding data packet.

Especially when the puncturing rate is between 1/2 and 5/9 or the coding rate between 2/3 and 3/4 is achieved in the invention, that all parity bit in the first data packet or in the first repeat data packet or be transmitted exactly once in the second repeat data packet.

Preferably the punctuation rate of the rate matching algorithm is in the range between 2/3 and 3/4; that is the case when between 1/2 and 5/9 the bit will be punctured. In this case, at the first transmission (and the third) between 1/4 and 1/6 of the parity bits and in the second transmission at least 4/6 of the parity bits, in total, can So in Erst- second and third transfer transmit all parity bits become. In the retransmission could while theoretically more parity bits are transmitted, namely between 4/6 and 3/4. According to the invention but only the first transmission and the second retransmission still missing parity bit transferred.

Preferably the coding rate of the turbo coder is taken into account the rate adjustment between 2/3 and 3/4.

The In particular, the invention considers the case that between 1/2 and 5/9 of the bits are punctured. This corresponds to a coding rate between 2/3 and 3/4. In the context of this invention, the influence the so-called tail bits on those generated by turbo code Bits not closer considered. As in UMTS, one can e.g. one third of the termination bits the systematic bit, the parity 1 and the parity 2 bits strike. Strictly speaking, the coding rate is due to the influence of the termination bits a little lower than stated, because you can calculate the coding rate Strictly speaking, the termination bits would also have to be considered. These But fineness is for the invention irrelevant, which is why both types of calculation by the invention is included. For the invention is the total number of parity 1 and parity 2 bits relevant, independent of whether it is "real" parity bit or termination bit.

Of course it includes the invention also includes data transmissions, where besides the stipulated puncturing rates or code rates any other puncturing rates or code rates are used, wherein at the other puncturing rates or code rates also arbitrary other rate adaptation methods or initial values for the error variable can be used. In particular, data transfers are in the Frame of the invention, in which at a puncture rate between 1/2 and 5/9 apply rate matching or bit selection according to the method claims and at other puncturing rates, rate matching or bit selection according to the state the technique, in particular according to the rate matching algorithm according to the currently current UMTS standard (see above) is used.

in the The scope of the invention is also a hardware technology and / or software technology accordingly arranged Sen the, in particular a mobile station or a base station, and a hardware and / or according to software technically configured receiver, the in particular a base station or a mobile station.

• – dass Daten durch eine Turbo-Codierung in systematische Bit und Paritätsbit umgesetzt werden,
• – dass von dem Sender an einen Empfänger ein erstes Datenpaket gesendet wird, das die systematischen Bit enthält und einen Teil der Paritätsbit enthält, und
• – dass bei Vorliegen einer entsprechenden Aufforderung des Empfängers mindestens ein Wiederholungsdatenpaket an den Empfänger gesendet wird, das keine Paritätsbit enthält, die im ersten Datenpaket enthalten sind.

The transmitter comprises a processor device which is set up in such a way

• That data is converted into systematic bits and parity bits by a turbo-coding,
• - that from the transmitter to a receiver, a first data packet is sent containing the systematic bits and contains a part of the parity bit, and
• If at least one retry data packet is sent to the receiver, which does not contain any parity bits contained in the first data packet, if there is a corresponding request from the receiver.

• – dass ein erstes Datenpaket, das die systematischen Bit und einen Teil der Paritätsbit enthält, empfangen wird,
• – dass ein Widerholungsdatenpaket vom Sender angefordert wird, wenn das erste Datenpaket empfangsseitig nicht korrekt decodiert wird, und
• – dass ein gesendetes Wiederholungsdatenpaket empfangen wird, das keine Paritätsbit enthält, die im ersten Datenpaket enthalten sind.

The receiver for receiving data in the form of data packets, the data being converted by a turbo-coding into systematic bits and parity bits, comprises a processor device which is set up in such a way that

• That a first data packet containing the systematic bit and a part of the parity bit is received,
• - That a retry data packet is requested by the transmitter when the first data packet receiving not correctly decoded on the side, and
• - Receiving a transmitted repeat data packet containing no parity bits contained in the first data packet.

The The present invention will be explained in more detail below with reference to FIGS attached Drawings based on preferred embodiments of a packet-oriented data transfer explained in a mobile radio system, Of course, the present invention does not apply to mobile radio systems is limited but generally used in any kind of communication systems in particular an ARQ method for data transmission is provided.

1 shows a representation to clarify the signal processing according to a packet-oriented ARQ method,

2 shows a representation to illustrate the communication in a mobile radio system.

As has already been explained above, it is assumed below that, with the aid of the present invention, a packet-oriented data transmission in a mobile radio system, as shown schematically in FIG 2 is shown to be realized. It is in 2 exemplifies the communication between a base station 1 and a mobile station 2 a mobile radio system, for example a UMTS mobile radio system represented. The transmission of information from the base station 1 to the mobile station 2 takes place via the so-called "downlink" channel DL, while transmitting the information from the mobile station 2 to the base station 1 via the so-called "uplink" channel UL.

The present invention will now be described by way of example with reference to a packet-oriented data transmission from the base station 1 to the mobile station 2 , ie, explained by packet-oriented data transmission over the "downlink" channel, but the present invention is analogously applicable to data transmission over the "uplink" channel. Furthermore, the present invention is explained below with reference to the signal processing measures to be carried out in the respective transmitter, wherein, however, in the respective receiver for evaluating the data processed in this way senderseitiq corresponding signal processing in reverse order is required, so that present invention, not only the transmitter side, but also the receiver side is concerned and encompassed. Although no puncturing is made in the receiver in the sense that bits are selected from a bit stream which are then not transmitted. However, the receiver preferably implements a corresponding algorithm that takes into account which bits have been punctured, that is, not transmitted, to correctly determine the relationship of the actual transmitted bits to the bits of the original coded bitstream. Of course, the punctured bits can not be recovered, but at the receiving end, the identity of the transmitted bits is correctly detected in order to use them correctly for decoding.

In 1 the signal processing of the data and header information to be transmitted in the data packets is shown according to a hybrid ARQ method.

On the header side are those of a function block 3 generated header information a function block 12 which ensures that all headers of all data packets to be sent in one and the same radio packet are combined into a single header (so-called header concatenation). A functional block 13 adds CRC bits for header recognition to the resulting header information. Subsequently, by a function block 14 a channel coding and a functional block 15 rate matching of the resulting bitstream. An interleaver 16 causes the symbols or bits supplied to it to be reordered and spread in a specific manner. The one from the interleaver 16 output data blocks are from a function block 17 assigned to the individual transmission or radio frames (so-called "radio frame segmentation"). However, the coding of the header information is only of secondary importance for the invention.

On the data page is also a function block 4 provided for adding CRC bits. A functional block 5 serves for the splitting of a channel encoder 6 supplied data such that from the channel coder 6 always a limited to a certain number of bits encoding can be performed.

By the channel coder 6 performed channel coding will actually send the Data redundant information added. This has the consequence that several data packets transmitted one after the other have bits with the same information origin.

Those of the channel coder 6 output bits become a function block 19 fed, which adjusts the bit rate of the bit stream by hiding or omitting individual bits (so-called puncturing) or by repeating individual bits (so-called repetition). From a subsequent function block 9 For example, so-called DTX bits ("discontinuous transmission") can be added to the data stream. Furthermore, function blocks are also on the data page 10 and 11 provided the same functions as the function blocks provided on the header side 16 and 17 perceive.

Finally, the bits output on the data and header side are from a function block 18 mapped or multiplexed on the respectively present physical transmission or transmission channel (so-called "multiplexing") and with the aid of a suitable modulation, for example a QAM modulation, transmitted to the receiver.

at The Hybrid ARQ Type I method will fail if received or a faulty decoding of a data packet by the receiver a repeat data packet requested, which with the previously sent and incorrectly received data packet completely or partially identical is. Depending on whether the retry data packet is less or equal to how much data the original one Data packet is characterized by a full or partial repetition spoken. The data packet and the respective repeat data packet thus have bits with an at least partially identical information origin on. The recipient can thus by common evaluation of the originally sent data packet and the requested subsequent retry data packets originally regain sent information with better quality.

The present invention relates essentially to the in 1 shown function section 19 , This functional section 19 includes a functional block 20 , which depends on a control by the function block 3 that from the upstream channel encoder 6 output coded bits to at least two parallel partial bit streams, which are each separately, ie independently, subjected to a rate adaptation. In 1 In this regard, three partial bit streams A-C are shown, with one functional block for each partial bit stream 21 - 23 to perform a corresponding rate adaptation, ie for puncturing or repetition of individual bits, is provided. In this way, several differently coded parallel partial bit streams, which form a further functional block 24 be supplied. This further functional block 24 The task is to separate the individual bits of the parallel bit streams in the same order as that of the function block 20 for the bit separation, ie for the division on individual parallel partial bit streams, has been used to collect (bit collection).

On This way, it ensures that the overall order is the left after the rate adjustment remaining bits does not change.

As has already been explained above, the rate adaptation provided for the individual partial bit streams A-C by the function blocks 21 - 23 completely independent of each other. In particular, the bits of one or more sub-bit streams can not undergo puncturing or repetition at all. Overall, the rate adaptation of the individual parallel partial bit streams A-C is to be selected such that of the entire functional section 19 on the one from the function block 6 output channel-coded bit stream per data packet or repetition data packet, a desired rate matching pattern is applied. With the in 1 shown realization of the functional section 19 with multiple parallel rate adjustments, extremely high coding flexibility can be achieved.

The functional section 19 is configured such that it depends on the control by the function block 3 apply a different rate matching pattern to the bits of a repetition data packet than to the bits of the corresponding originally transmitted data packet. That is the functional section 19 is from the function block 3 informed whether a repeat data packet has been requested by the respective recipient, the functional section 19 in this case those of the individual function blocks 21 - 23 realizes rate matching pattern such that, overall, the bits of the repeat data packet are processed with a different rate matching pattern than the bits of the underlying originally transmitted data packet.

The total of the functional section 19 For example, realized rate matching may be done according to the rate matching algorithm, which in itself is already known from the prior art (see above) knows is to be performed.

• – Zur Datenübertragung in Form von Datenpaketen werden die Daten durch eine Kanalcodierung, insbesondere eine Turbo-Codierung, in systematische Bit und Paritätsbit umgesetzt. Von dem Sender wird an den Empfänger ein erstes Datenpaket gesendet, das die systematischen Bit und einen Teil der Paritätsbit enthält. Bei Vorliegen einer entsprechenden Aufforderung des Empfängers (2) wird mindestens ein Wiederholungsdatenpaket an den Empfänger (2) gesendet, das die Paritätsbit enthält, die im ersten Datenpaket nicht enthalten sind.
• – Das Wiederholungsdatenpaket enthält keine Paritätsbit, die im ersten Datenpaket enthalten sind.
• – Das Wiederholungsdatenpaket enthält neben den Paritätsbit, die im ersten Datenpaket nicht enthalten sind, systematische Bit.
• – Die Kodierungsrate des Turbocoders liegt unter Berücksichtigung der Ratenanpassung zwischen 2/3 und ½.
• – Die in einem Datenpaket oder Wiederholungsdatenpaket enthaltenen Paritätsbit werden durch einen Ratenanpassungsalgorithmus aus den aus der Turbocodierung resultierenden Paritätsbit ausgewählt.
• – Die Punktierungsrate des Ratenanpassungsalgorithmus liegt zwischen ½ und 1/3.
• – Der Initialwert der Fehlervariablen des Ratenanpassungsalgorithmus wird derart gewählt, dass das Wiederholungsdatenpaket keine Paritätsbits enthält, die im ersten Datenpaket enthalten sind.
• – Der Ratenanpassungsalgorithmus enthält folgende Verfahrensschritte: a) Setzen der Fehlervariablen auf den Initialwert b) Setzen des Bitindex auf das erste Bit c) Subtraktion des Erniedrigungswertes der Fehlervariablen von der Fehlervariablen. d) Falls die Fehlervariable kleiner oder gleich 0 ist durchführen der Schritte e) bis f) e) Punktieren des durch den Bitindex angezeigten Bit f) Addition des Erhöhungs-Wert zur Fehlervariablen g) Erhöhen des Bitindex h) wiederholen der Schritte c) bis g), bis der Bitindex die Anzahl der zu verarbeitenden Bit überschreitet.
• – Für den Einsatz des Ratenanpassungsalgorithmus zur Auswahl der im ersten Datenpaket enthaltenen Paritätsbit gilt: eini(r) = {(Xi – ⌊r·eplus/rmax⌋ – 1 mod eplus} + 1und im Wiederholungsdatenpaket enthaltenen Paritätsbit gilt: eini(r) = {(Xi – ⌈(r + 1)·eplus/rmax⌉)mod eplus} + 1,wobei gilt: e_ini(r) = der Initialwert für die Fehlervariable; r = 0, falls der Ratenanpassungsalgorithmus in Zusammenhang mit dem ersten Datenpaket angewendet wird; r = 1, falls der Ratenanpassungsalgorithmus in Zusammenhang mit dem Wiederholungsdatenpaket angewendet wird.

The just explained functional sections, in particular the functional section 19 , may be set up so that one or more of the following configurations are put into practice:

• - For data transmission in the form of data packets, the data is converted by a channel coding, in particular a turbo-coding, into systematic bit and parity bit. The sender sends to the receiver a first data packet containing the systematic bits and part of the parity bits. If there is a corresponding request from the beneficiary ( 2 ) at least one repeat data packet is sent to the receiver ( 2 ) containing the parity bits not included in the first data packet.
• The retry data packet contains no parity bits contained in the first data packet.
• The repetition data packet contains systematic bits in addition to the parity bits which are not contained in the first data packet.
• - The coding rate of the turbo coder is between 2/3 and ½, taking into account the rate adaptation.
• The parity bits contained in a data packet or repetition data packet are selected by a rate matching algorithm from the turbo-coding resulting parity bits.
• The puncturing rate of the rate matching algorithm is between ½ and 1/3.
• The initial value of the error variable of the rate matching algorithm is chosen such that the repeat data packet does not contain any parity bits contained in the first data packet.
• The rate matching algorithm contains the following method steps: a) setting the error variable to the initial value b) setting the bit index to the first bit c) subtracting the reduction value of the error variable from the error variable. d) If the error variable is less than or equal to 0, perform steps e) to f) e) puncturing the bit index indicated by the bit index f) adding the increment value to the error variable g) incrementing the bit index h) repeating steps c) through g ) until the bit index exceeds the number of bits to be processed.
• The following applies to the use of the rate matching algorithm for selecting the parity bits contained in the first data packet: e ini (r) = {(X i - ·r · e plus / r Max ⌋ - 1 mod e plus } + 1 and the parity bit contained in the retry data packet: e ini (r) = {(X i - ⌈ (r + 1) · e plus / r Max ⌉)Fashion plus } + 1, where: e _ini (r) = the initial value for the error variable; r = 0 if the rate matching algorithm is applied in conjunction with the first data packet; r = 1 if the rate matching algorithm is used in conjunction with the repeat data packet.

At the receiving end the first data packet and the repeat data packet are combined, in particular by so-called combining soft combining (summarizing the soft-decission values, so summarizing the probabilities that individual bits have the value 1 or 0), decoded.

The embodiments just explained are particularly suitable for the case where the coding rate is in the range between 2/3 and 1/2; this is the case when puncturing between 1/2 and 1/3 of the bits. In this case, between 1/4 and 1/2 of the parity bits are transmitted during the first transmission and at least 3/4 of the parity bits in the second transmission, so that all parity bits can be transmitted in the first and second transmission. At higher coding rates than 2/3, this is no longer the case, so the formulas given above are then preferably not applied directly. In particular, it is then no longer possible to select for the second transmission exactly the parity bits which were not transmitted in the first transmission since not all the missing ones can be transmitted in the secondary transmission. However, the Start value e _ini preferably be chosen so that there is the least possible overlap between the parity bits that are sent on the first and second times.

In the following, however, solutions are also given for this case:
In this case, it is impossible to transmit all the parity bits after the second transmission. But this can be possible again after the third transmission. Conveniently, one uses at a coding rate that is not too much over 2/3, for the third transmission again a transmission that prioritizes the systematic bit; this is already provided in the standard. The puncturing patterns for the 1st and 3rd transmission are shifted against each other. It is possible, by suitable choice of the parameter e _ini for the 3rd transmission, to have the amount of parity bits transmitted in the 1st and 3rd transmission taken together having a similar distribution (a similar pattern) a single transmission, but twice as many bits are transmitted. The second transmission can now be optimized to transmit exactly those bits that are transmitted neither in the first transmission nor in the third transmission. In this case, the above-mentioned formulas can be used in an analogous manner, whereby, of course, it is taken into account that twice as many parity bits are transmitted in the first and third transmission as in the first transmission alone. The formulas for optimally choosing the parity 1 bit and parity 2 bits to be transmitted in the second transmission can then be derived as follows: Determine an equivalent rate adaptation that selects the parity 1 and parity 2 bits transmitted in the first or third transmission , The number of transmitted bits corresponds to the sum, the value of eini should be determined accordingly. Possibly. if one chooses the value of one for the third transmission appropriately (in relation to the value of one for the first transmission) that these two transmissions can be grouped together to give a total transmission pattern, as in a single transmission. The value for the number of parity 1 and parity 2 bits to be transmitted and the value of one for the second transmission can then be determined on the basis of the pattern combined for this, as described above.

Chapter 4.5.4.3 defines in Table 10 how to calculate the parameters e _plus , e _minus and X _i for the systematic bits, the parity 1 bit (first parity bit) and the parity 2 bit (second parity bit for the rate matching algorithm) :

To simplify the nomenclature, we introduce the parameter a, which takes the value 2 for the parity 1 bit and the value 1 for the parity 2 bits. Then for both types of parity bits applies to the case of puncturing considered here: eplus = a N p and eminus = a abs (N p - N t, p ) = a (N p - N t, p )

N _p1 and N _p2 or generalize N _p the number of parity 1 or parity 2 bits before the rate adaptation, N _{t, p1} and N _{t, p2} or generalizes N _{t, p} the number of transmitted parity 1 or Parity 2 bits. The task now is to parameterize the third transmission so that in the first and third transmission taken together the same bits are transmitted as in a transmission that transmits twice as many parity bits as well as to determine the parameters for this hypothetical transmission. If necessary, the parameters used in this hypothetical transmission are indicated by the index h. In such a transmission, the value eminus would be set to a ( _Np -2N _{t, p} ) since twice as many bits are transmitted; the value eplus would be unchanged.

We formulate the algorithm further to the algorithm A3: Algorithm for analysis the combined transmission, called A3:

The value of e at each non-transmitted, so punctured bits to the value eplus as is easily seen when viewing the algorithm A2 is - eminus = a N _p - a (N _p - N _{t, p)} = a N _{t, p} elevated. For each transmitted bit e is decremented by the value eminus = a N _p . The reduction value is the same for the first, third and hypothetical transfer, but the increase value for the hypothetical transfer is twice as large. The result is, if one plots the value of e over m each a sawtooth-like curve, the height of the spikes is the same, but the slope of the spikes for the hypothetical curve twice as large and thus the number of spikes. Each spike corresponds to a transmitted bit. The aim is to find a parameterization for the hypothetical transmission in which exactly the bits transmitted in the first and second transmission are transmitted together. For this purpose, the third and first transmission must be well nested, which can be achieved if their values differ from one half the value of the increase value, ie if the difference is (a N _{t, p} / 2). This is already the case according to the current state of the standard. If one chooses the value of e at the first if query for both the first and the hypothetical transmission to be equal to 1, then the "saw teeth" fit appropriately, but this is not the case by default, but one can do a proper alignment If one considers the double slope of the sawtooth curve, then the distance of 1 (the comparison value in the query) for the hypothetical transmission must be twice as large as for the first transmission: 2 (1 - e 1 (m = 1)) = (1 - e H (m = 1))

From this one can also calculate the corresponding value of one for the hypothetical transmission, since e (m = 1) = e _ini - e _plus . Again, from the value of e _ini for the hypothetical transmission, analogously, as already shown, the necessary value of e _ini for the second transmission can be calculated, so that the bits of the second transmission are exactly the bits that are not transmitted in the hypothetical transmission and thus exactly those which are not transmitted in either the first or the third transmission.

und analog:

The number of systematic or parity 1 and parity 2 bits to be transmitted in the second transmission is then in the range of the coding rate discussed here, ie if (4/3) N _sys ≦ N _data <1.5 N _sys :

and analogously:

The result for the second transmission is the formula e ini2 = (X i Fashion plus · 2 + 2.

This Value hangs not that in the first transmission used value of r, which is also logical: if in the first transmission the value r = 0 is used, so in the third transmission the value r = 1 is used. If the value r = 1 is used in the first transfer would, so would have to in the third transmission the value r = 0 can be used. Both times will be in the first you third transfer taken together transmit the same bits, so that both times for the second transmission the same parameterization results.

Of course, it is quite possible, using the parameter r, to define another transmission which contains bits other than the second transmission, and which could then be used, for example, in a fourth transmission. As already stated in the specification, this would be done by modifying the value of e _ini by r * e _plus / r _max . In order to maintain the convention that the second transmission is transmitted with r = 1 and that r _max = 2, the additive term results: (1 - r) e plus / r Max

The formula for e _ini for the parity bits of the retry _{data packet} would thus be: e ini2 (r) = {(2X i - ⌈ (1 - r) · e plus / r Max ⌉)Fashion plus } + 2 this formula does not yet take into account that the value of e _{ini should} always be between 1 and e _plus , one can achieve this by the Umformumg e ini2 (r) = {(2X i + 1 - ⌈ (1 - r) · e plus / r Max ⌉)Fashion plus } + 1 and further, since r _max = 2 and considering the modulo function e ini2 (r) = {(2X i + 1 - ⌈ (r + 1) · e plus / r Max ⌉)Fashion plus } + 1

Note: Unlike in the case of the code rate being between ½ and 2/3, in this case it is not particularly relevant whether the above calculation rounds up or down, since now for the second transmission, r = 1, then If (r + 1) e _plus / r _max = e _plus and e _plus is already an integer, the rounding does nothing in this case and thus it is irrelevant whether it is rounded up or down.

This embodiment is again illustrated by a table. Again, consider the case where there are 20 systematic (and 20 parityl or parity2 bits each) after encoding. It is now assumed that 28 bits of this can be transmitted with each transmission. Then the following values result for e and the following transmitted bits:

The Designation is according to the above table.

1:

erste Übertragung,

3:

dritte Übertragung,

2:

Zweite Übertragung nach dem Stand der Technik,

hyp 1 + 3:

Hypothetische Übertragung, die die Parity Bit der ersten und dritten Übertragung umfasst,

1 + 3:

zum Vergleich dazu die in der ersten und dritten Übertragung übertragenen Bit

1 – 3:

in der ersten bis dritten Übertragung übertragene Bit

2 opt:

zweite Übertragung nach dem Ausführungsbeispiel

1 – 3 opt:

in der ersten bis dritten Übertragung übertragene Bit nach dem Ausführungsbeispiel

1 + 2 opt:

in der ersten und zweiten Übertragung übertragene Bit nach dem Ausführungsbeispiel

1 + 2:

in der ersten und zweiten Übertragung übertragene Bit nach dem Stand der Technik

The columns indicate:

1:

first transmission,

3:

third transmission,

2:

Second transmission according to the prior art,

hyp 1 + 3:

Hypothetical transmission comprising the parity bits of the first and third transmission,

1 + 3:

for comparison, the bits transmitted in the first and third transmission

1 - 3:

bits transmitted in the first to third transmissions

2 opt:

second transmission according to the embodiment

1 - 3 opt:

in the first to third transmission transmitted bits according to the embodiment

1 + 2 opt:

in the first and second transmission transmitted bits according to the embodiment

1 + 2:

bits transmitted in the first and second transmission according to the prior art

In the columns below there are some parameters listed:
Transmitted parity 1 bits
Transmitted Systematic bits:
X _i
e _plus
e _minus
r
e _ini

Then the values of the parameter e as a function of m follow and the transmitted bits are on gezeichent.

you sees that the parameters of the hypothetical transfer actually so chosen are that same bits selected become, as in the first and third transmission together. Furthermore it can be seen that in the first to third transmission according to the embodiment transmit all parity bits be, unlike the prior art. In the last two Columns are shown that after the invention not only after the third transmission gives an advantage, but already after the second transmission. Although in this example in the second transmission according to the embodiment only 12 instead of 14 as in the state of the art transmits conditions, is the total number in the first and second transmission transmitted according to the embodiment Parity bit equal to 16 and thus higher as in the prior art (14).

These Invention is particularly suitable in the event that the coding rate is in the range between 2/3 and 3/4; that is the case when between 1/2 and 5/9 of the bits are punctured. In this case, at the first transmission (and the third) between 1/4 and 1/6 of the parity bits and in the second transmission At least 4/6 of the parity bits, in total, can therefore be used in first and second Third-transfer transmit all parity bits become. At higher Coding rates than 3/4 this is no longer the case, therefore the formulas given above are then preferably not applied directly.

Alternatively, the following procedure is also possible for determining suitable values for e _ini : As in the case where the coding rate is between ½ and 2/3, formulas for the three rate matching algorithms are written down, except that in this case they are three instead of two , Then it is determined that for each value of m, one bit is always used for exactly one algorithm. Analogously, as shown above, this leads to corresponding conditions for the values of e in the three algorithms and thus also for the values of e _ini .

This embodiment is explained by a numerical example:
Suppose that a transmission consists of 100 systematic bits each, parity 1 bit and parity 3 bits, ie a total of 300 bits. Suppose further that 140 bits are transmitted in a transmission. In the first (and also in the third) transmission, the 100 systematic bits and 20 each parity 1 and parity 2 bits are transmitted. Together in 1st and 3rd transmission so each 40 parity 1 and parity 2 bits. thus missing 60 parity 1 and parity 2 bits each. Exactly these bits are now transmitted in the second transmission. In order to get the total number of 140 bits again, in the second transmission also 140-60-60 = 20 systematic bits are transmitted. This embodiment can be applied if at least 1/6 of the parityl (or parity 2) bits are transmitted in the first transmission. Then 1/6 can also be transmitted in the third transmission, in the second transmission at least ½ + 1/6 = 2/3 of the parity bits can be transmitted, that is, together at least 2/3 + 1/6 + 1/6 = 1/1 all parity bits. This embodiment is therefore particularly applicable for coding rates between 2/3 and ¾ = 0.75.

This embodiment is described below in further formulas: Let N be the number of systematic bits; this is at the same time the number of parityl and also the parity2 bit (a generalization to the case that these numbers are different is easily possible but will be omitted here for the sake of clarity) Let Ns1 = Ns3, N11 = N13 and N21 = N23 the Number of systematic, parityl and parityl bits transmitted in the first (and third) transmission. Let Ns2, N12 and N22 be the number of systematic, parityl and parityl bits to be transmitted in the second transmission. Then: N12 = N - N11 - N13 N22 = N - N21 - N23 Ns2 = Ns1 + N11 - N12 + N21 - N22 = Ns1 + N11 + N21 - N + N11 + N13 - N + N21 + N23 = Ns1 + N13 + N23 + 2 · (N11 + N21 - N)

The last line is simply the expression that the remaining bits filled with systematic bit be, so bring for the practice no further computational simplification but is more one alternative presentation.

This generalization of the method according to the invention thus allows the application up to quite high coding rates for the first transmission. At even higher rates, ie a rate greater than ¾, one needs two retransmissions, which prefer parity bits, to a total of three transmissions to transmit all parity bits. In this case, all the parity bits are already transmitted by the two retransmissions, so that it is not decisive for the performance after receipt of the third transmission which of the parity bits were additionally sent in the first transmission. However, in order to improve the performance after the second transmission, it is still desirable that in the second transmission (first retransmission) those parity bits are transmitted which were not transmitted in the first transmission. In this respect, the invention can be applied in a modified form also in this case. In particular, the value of e _{ini should} again be chosen such that there are as few overlaps as possible, and it may again be advantageous to send less parity bit in a transmission than would be possible in order to achieve a better intermeshing of the patterns.

alternative you can at a higher Encoding rate as 3/4 and more than two transmissions with s = 1 with a transmission combine with s = 0. Again, one sets the shift of Puncturing pattern of parity bits of multiple transmissions with s = 1 so, that in combination the pattern results as in a single one hypothetical transmission and designed the transmission with s = 0 so that just the missing bits are transferred become. This is a generalization of the coding rate method given above between 2/3 and 3/4. As another alternative, one can the invention apply even if fewer transmissions are performed with s = 1, as actually needed Then one also determines a hypothetical transmission the all parity bit both of the carried out transfers with s = 1 so also the non-sent and designed the transmission with s = 0 such that in this case just those not transferred in the hypothetical transfer Transmit bit become.

• – Zur Datenübertragung in Form von Datenpaketen werden die Daten durch eine Kanalcodierung, insbesondere eine Turbo-Codierung, in systematische Bit und Paritätsbit umgesetzt. Von dem Sender wird an den Empfänger ein erstes Datenpaket gesendet, das die systematischen Bit und einen Teil der Paritätsbit enthält. Bei Vorliegen einer entsprechenden Aufforderung des Empfängers (2) wird mindestens ein Wiederholungsdatenpaket an den Empfänger (2) gesendet, das keine Paritätsbit enthält, die im ersten Datenpaket enthalten sind.
• – Ein erstes Wiederholungsdatenpaket enthält die Paritätsbit, die weder im ersten Datenpaket noch in einem weiteren Wiederholungsdatenpaket enthalten sind.
• – Das erste Wiederholungsdatenpaket enthält neben Paritätsbit, die im ersten Datenpaket nicht enthalten sind, systematische Bit.
• – Das zweite Wiederholungsdatenpaket enthält die Paritätsbit, die weder im ersten Datenpaket noch im ersten Wiederholungsdatenpaket enthalten sind.
• – Die Kodierungsrate des Turbocoders liegt unter Berücksichtigung der Ratenanpassung zwischen 2/3 und 3/4.
• – Die in einem Datenpaket oder Wiederholungsdatenpaket enthaltenen Paritätsbit werden durch einen Ratenanpassungsalgorithmus aus den aus der Turbocodierung resultierenden Paritätsbit ausgewählt.
• – Die Punktierungsrate des Ratenanpassungsalgorithmus liegt zwischen 1/2 und 5/9.
• – Der Initialwert der Fehlervariablen des Ratenanpassungsalgorithmus wird derart gewählt, dass das erste Wiederholungsdatenpaket keine Paritätsbits enthält, die im ersten Datenpaket enthalten sind.
• – Der Initialwert der Fehlervariablen des Ratenanpassungsalgorithmus wird derart gewählt, dass das erste Wiederholungsdatenpaket solche Paritätsbits enthält, die weder im ersten Datenpaket noch in einem weiteren Wiederholungsdatenpaket enthalten sind.
• – Der Ratenanpassungsalgorithmus enthält folgende Verfahrensschritte: a) Setzen der Fehlervariablen auf den Initialwert, b) Setzen des Bitindex auf das erste Bit, c) Subtraktion des Erniedrigungswertes der Fehlervariablen von der Fehlervariablen, d) Falls die Fehlervariable kleiner oder gleich 0 ist durchführen der Schritte e) bis f), e) Punktieren des durch den Bitindex angezeigten Bit, f) Addition des Erhöhungs-Wert zur Fehlervariablen, g) Erhöhen des Bitindex, h) wiederholen der Schritte c) bis g), bis der Bitindex die Anzahl der zu verarbeitenden Bit überschreitet.
• – Für den Einsatz des Ratenanpassungsalgorithmus zur Auswahl der Paritätsbit im ersten Datenpaket gilt: eini(r) = {(Xi – ⌊r·eplus/rmax⌋ – 1)mod eplus} + 1,
• – bei dem für den Einsatz des Ratenanpassungsalgorithmus zur Auswahl der Paritätsbit im ersten Wiederholungsdatenpaket gilt: eini(r) = {(2Xi + 1 – ⌈(r + 1)·eplus/rmax⌉)mod eplus} + 1,wobei gilt: e_ini(r) = der Initialwert für die Fehlervariable; r = 0, falls der Ratenanpassungsalgorithmus in Zusammenhang mit dem ersten Datenpaket angewendet wird; r = 1, falls der Ratenanpassungsalgorithmus in Zusammenhang mit dem Wiederholungsdatenpaket angewendet wird; rmax = 2.
• – Es gilt. Nt,sys = 3Ndata – 4Nsys;
  
  dabei bezeichnet Ndata: Verfügbare Bit für die Übertragung Nsys: Anzahl der systematischen Bit vor der Ratenanpassung Nt, sys: Anzahl der systematischen Bit nach der Ratenanpassung Nt, p1: Anzahl der Parity 1 Bit nach der Ratenanpassung Nt, p2: Anzahl der Parity 2 Bit nach der Ratenanpassung.

The functional section explained above, in particular the functional section 19 , may be set up so that one or more of the following configurations are put into practice:

• - For data transmission in the form of data packets, the data is converted by a channel coding, in particular a turbo-coding, into systematic bit and parity bit. The sender sends to the receiver a first data packet containing the systematic bits and part of the parity bits. If there is a corresponding request from the beneficiary ( 2 ) at least one repeat data packet is sent to the receiver ( 2 ) containing no parity bits contained in the first data packet.
• A first retry data packet contains the parity bits which are neither contained in the first data packet nor in a further retry data packet.
• The first retry data packet contains systematic bits in addition to parity bits that are not contained in the first data packet.
• The second repetition data packet contains the parity bits which are contained neither in the first data packet nor in the first repetition data packet.
• - The coding rate of the turbo coder is between 2/3 and 3/4, taking into account the rate adaptation.
• The parity bits contained in a data packet or repetition data packet are selected by a rate matching algorithm from the turbo-coding resulting parity bits.
• The puncturing rate of the rate matching algorithm is between 1/2 and 5/9.
• The initial value of the error variable of the rate matching algorithm is chosen such that the first repeat data packet does not contain any parity bits contained in the first data packet.
• The initial value of the error variable of the rate matching algorithm is chosen such that the first repetition data packet contains such parity bits which are contained neither in the first data packet nor in a further repetition data packet.
• The rate matching algorithm comprises the following method steps: a) setting the error variable to the initial value, b) setting the bit index to the first bit, c) subtracting the reduction value of the error variable from the error variable, d) if the error variable is less than or equal to 0, perform the steps e) to f), e) puncturing the bit index indicated by the bit index, f) adding the increment value to the error variable, g) increasing the bit index, h) repeating steps c) to g) until the bit index increases the number of exceeds the processing bit.
• The following applies to the use of the rate matching algorithm for selecting the parity bits in the first data packet: e ini (r) = {(X i - ·r · e plus / r Max ⌋ - 1) mod e plus } + 1,
• In which the following applies to the use of the rate matching algorithm for selecting the parity bits in the first repeat data packet: e ini (r) = {(2X i + 1 - ⌈ (r + 1) · e plus / r Max ⌉)Fashion plus } + 1, where: e _ini (r) = the initial value for the error variable; r = 0 if the rate matching algorithm is applied in conjunction with the first data packet; r = 1 if the rate matching algorithm is applied in conjunction with the repeat data packet; rmax = 2.
• - It applies. N t, sys = 3N data - 4N sys ;
  
  Ndata means: Available bits for transmission Nsys: Number of systematic bits before rate adaptation Nt, sys: Number of systematic bits after rate adaptation Nt, p1: Number of parity 1 bit after rate adaptation Nt, p2: Number of parity 2 bits after the rate adjustment.

Claims (14)

Data transmission method in the form of data packets, in which data is converted into systematic bits and parity bits by turbo coding, in which a first data packet containing the systematic bits and a part of the parity bits is sent by the transmitter to the receiver and, if an appropriate request has been made by the beneficiary ( 2 ) at least one retry data packet to the recipient ( 2 ) containing no parity bits contained in the first data packet. Method according to claim 1, - in which a first retry data packet the parity bit contains neither in the first data packet nor in another repeat data packet are included. Method according to one of the preceding claims, - in which the first repeating data packet next to the parity bit in the first data packet not included, contains systematic bit. Method according to one of the preceding claims, - in which the second repeating data packet contains the parity bits that are not in the first data packet are still included in the first repeat data packet. Method according to one of the preceding claims, - in which the coding rate of the turbo coder taking into account the rate adaptation between 2/3 and 3/4. Method according to one of the preceding claims, - in which those contained in a data packet or retry data packet parity by a rate matching algorithm from the turbo coding resulting parity bit selected become. Method according to one of the preceding claims, - in which the puncturing rate of the rate matching algorithm between 1/2 and 5/9 lies. Method according to one of the preceding claims, In which the initial value of the error variable of the rate matching algorithm is chosen such that the first repeat data packet does not contain any parity bits contained in the first data packet. Method according to one of the preceding claims, - in which the initial value of the error variable of the rate matching algorithm chosen like that is that the first repeat data packet contains such parity bits that neither in the first data packet nor in another repeat data packet are included. Method according to one of claims 6 to 9, - in which the rate matching algorithm includes the following steps: a) Setting the error variable to the initial value, b) setting the Bit index on the first bit, c) Subtraction of the reduction value the error variable from the error variable, d) If the error variable less than or equal to 0 is performing of steps e) to f), e) puncturing by the bit index displayed bit, f) addition of the increase value to the error variable, G) Increase the bit index, h) repeating steps c) to g) until the Bit index exceeds the number of bits to be processed. Method according to Claim 10, - in which the following applies to the use of the rate matching algorithm for selecting the parity bits in the first data packet: e ini (r) = {(X i - ·r · e plus / r Max ⌋ - 1) mod e plus } + 1, In which the following applies to the use of the rate matching algorithm for selecting the parity bits in the first repeat data packet: e ini (r) = {(X i + 1 - ⌈ (r + 1) · e plus / r Max ⌉)Fashion plus } + 1, where: e _ini (r) = the initial value for the error variable; r = 0 if the rate matching algorithm is applied in conjunction with the first data packet; r = 1 if the rate matching algorithm is applied in conjunction with the repeat data packet; rmax = 2. Method according to one of the preceding claims, in which: N t, sys = 3N data - 4N sys ;

where Ndata is: available bits for transmission Nsys: number of systematic bits before rate adaptation Nt, sys: number of systematic bits after rate adaptation Nt, p1: number of parity 1 bit after rate adaptation Nt, p2: number of parity 2 bits after the rate adjustment. Transmitter for transmitting data in the form of data packets with a processor device, which is set up such that - data is converted into systematic bit and parity bit by a turbo coding, - that a first data packet is transmitted from the transmitter to a receiver, which the contains systematic bit and contains a part of the parity bit, and - that if there is a corresponding request from the recipient ( 2 ) at least one repetition data packet to the receiver ( 2 ) containing no parity bits contained in the first data packet. receiver for receiving data in the form of data packets, wherein the data implemented by a turbo coding in systematic bit and parity bit are, with a processor device that is set up such - the existence first data packet containing the systematic bit and part of the parity contains Will be received, - that a retry data packet is requested from the sender if that first data packet is not decoded correctly on the receiving side, and - the existence sent repeated data packet containing no parity bit, the contained in the first data packet.