WO2003017539A1

WO2003017539A1 - Method for operating a radio system, corresponding radio system and corresponding emitter and receiver

Info

Publication number: WO2003017539A1
Application number: PCT/DE2002/002351
Authority: WO
Inventors: Siegfried Bär; Hyung-Nam Choi
Original assignee: Siemens Aktiengesellschaft
Priority date: 2001-08-01
Filing date: 2002-06-27
Publication date: 2003-02-27
Also published as: DE10137583A1

Abstract

According to the invention, a control message (SN) is sent from a first subscriber (BS) to a second subscriber (MS) in a radio system. Said second subscriber carries out measurements especially for the quality of transfer and sends the results of the measurements back to the emitter (BS) in a report message (BN). A plurality of formats are provided for the transfer of the control message (SN) and the report message (BN), the respective format used being transferred in an information message in the radio system. The control messages (SN) or report messages (BN) of various formats have especially different lengths, the length of at least one format being sufficiently small for the format to be transferred in a single time interval (1), in a radio system having a time interval structure. The first subscriber (BS) can modify the type of data transfer, especially the modulation and the codification, according to the measuring results transmitted in the report message (BN), in such a way that a data transfer rate is achieved which is as high as possible.

Description

description

Method for operating a radio system and correspondingly designed radio system and correspondingly designed transmitter and receiver

The present invention relates to a method for operating a radio system, in particular a mobile radio system, and a correspondingly designed radio system and correspondingly designed transmitter and receiver.

Mobile radio technology is developing rapidly. Work is currently underway on the standardization of the so-called UMTS mobile radio system ("Universal Mobile Telecommunication System") of the third mobile radio generation. With the help of this mobile radio system, its participants should be able to be offered a wide variety of services. The amount of data that has to be transmitted for the different services can be very different. For example, much more data is required to transmit image information than, for example, to transmit voice information. In the case of the aforementioned UMTS mobile radio system in particular, it is advantageous if transmission paths or channels with different data transmission rates are present. However, interference has a particularly disadvantageous effect on the transmission of data with a high transmission rate. In order to achieve the highest possible data transmission rate depending on the interference that occurs, it is therefore known to measure the interference in the radio system and, depending on this, to influence the type of data transmission in such a way that correct transmission is always achieved at the highest possible data transmission rate. To carry out the measurement with regard to the interference in the radio system, it is known to send a measurement control message from a transmitter to a receiver, which depending on it carries out measurements and sends the results back to the transmitter in a measurement report message. The messages exchanged include but numerous information elements, the transmission of which disadvantageously requires a longer period of time. In a radio system with a time frame structure, the transmission duration for these messages can disadvantageously be extended even further if, owing to the large number of information elements, the messages cannot be transmitted in one time frame, but instead have to be divided over several time frames.

The present invention is based on the object of proposing a method for operating a radio system, in particular a mobile radio system, by means of which the data transmissions which occur in the course of carrying out measurements can be carried out as effectively as possible with a high possible information content at the same time. Furthermore, the present invention is intended to provide a correspondingly designed radio system with a correspondingly designed transmitter and receiver. This object is achieved according to the invention by a method having the features of claim 1 or a radio system having the features of claim 25 and a transmitter according to claim 27 or a receiver according to claim 29. The subclaims each define preferred and advantageous embodiments of the present invention.

According to the invention, it is proposed to transmit the control message and / or the report message in a specific one of several possible formats. The different formats can relate in particular to the length of the messages. In this way, in the cases in which the fastest possible transmission of the messages is advantageous, the messages can be transmitted in a short format and thus faster.

However, the different formats can also relate to the information content of the messages, so that it depends on the purpose of the measurement to be carried out by the second participant a specific format is selected in which, in addition to the information required for this measurement, there is little or no further information in the messages.

Advantageously, only indicators are transmitted in the control message or the report message as information elements, which can be assigned according to a list known in the radio system. For this purpose, the list can indicate what type of information can be found at which point in the control message or the report message, so that a large amount of information can be transmitted with a small amount of data. In such a case, the control message or the report message is composed of so-called information elements, the meaning of which, however, must be known to the participants in the radio system.

The format information can be transmitted separately from the control message or the report message, but can also be part of the control message or the report message. If the messages contain indicators as information elements, the information element indicating the format or the corresponding indicator within the messages is advantageously always in the same place, so that the format information can be evaluated by any subscriber of the radio system even without knowledge of the format ,

A separate list for evaluating the indicators in the control message or the report message can be present for each format. Depending on the format information, the corresponding list is then used to evaluate the indicators.

With the help of the different formats for the control message or the report message, in particular the data transmission with a high data transmission rate can be improved. To Depending on the transfer conditions, the transfer type can be set so that the data is always transferred at the highest possible data transfer rate. For this purpose, the modulation and / or the coding of the transmitted signal can be changed and a high modulation and / or a high coding can be used to achieve a high data transmission rate. However, high modulation has the disadvantage of being more susceptible to disruptions in data transmission, so that they can only be used if the transmission conditions are good. In order to always be able to achieve the highest possible data transmission rate, it is therefore advantageous if the information about the transmission conditions or about the disturbances in the data transmission is available as quickly as possible. For this purpose, a format for the control and report message can be selected in which the control message or report message contains only a small number of information contents, so that the corresponding messages can be transmitted in a short time. In particular, it is packet data that are transmitted at a high transmission rate.

If the radio system is based on a tent slot structure, all data are transmitted divided into time slots, it being possible for a plurality of time slots to be combined into one frame. In this case, the transmission of a control message or report message is delayed by a multiple of the time slot duration as soon as the control message or report message is too long to be transmitted in a time slot. In order to avoid this, a maximum limit can be provided for the length of the control message or report message in a certain format, which in any case permits the transmission of the control message or report message in one time slot.

The measurements, in particular for determining the transmission conditions, can, for example, measure the received signal strength, the signal-to-interference ratio, the Signal-to-noise ratio or other measurement methods offered by the radio system.

The UMTS standard for radio systems already defines a number of measurement methods relating to radio transmission, in particular for determining the transmission quality, all of which can also be used in the context of the present invention.

In the transmission of digital data, digital modulation methods are used in particular, which can be, for example, quadrature phase modulation, 8-phase modulation, 16-quadrature amplitude modulation or 64-quadrature amplitude modulation. In all of these methods, the number of data transmitted in a unit of time increases with increasing modulation, but the susceptibility to interference increases to the same extent. The same applies to different code rates, which can be 1/4, 1/2 or 3/4, for example. In order to realize different data transmission rates depending on the disturbances occurring during the data transmission, different types of modulation and coding can be combined differently.

The present invention is preferably suitable for use in a mobile radio system, in particular in a UMTS mobile radio system. Of course, however, the present invention is not limited to the described field of application, but can advantageously be used in any radio system in which measurements are carried out, to which control information and / or report information must be transmitted. Both the transmitter side and the receiver side are affected by the present invention.

The present invention is explained in more detail below with reference to the accompanying drawing using a preferred embodiment. FIG. 1 shows a simplified illustration of a mobile radio cell of a mobile radio system operated according to the invention,

FIG. 2 shows the data transmission from a first subscriber to a second subscriber of the mobile radio system,

FIG. 3 shows the data transmission from the second subscriber to the first subscriber of the mobile radio system, and

Figure 4 shows the schematic structure of the information transmitted in the fiction, modern radio system ^¬ data.

In the following exemplary embodiment, a method for operating a radio system is described in which, depending on the transmission conditions in the radio system, the parameters of

Data transmission can be changed in order to achieve the highest possible data transmission. For this purpose, measurements are carried out with regard to the disturbances occurring during data transmission, the measurements being triggered by control messages and the results of the measurements being transmitted in the form of report messages. It should be noted, however, that the application of the invention is not limited to measurements relating to the transmission quality in the radio system, but can also be applied to other measurements. Likewise, the results of the measurements do not have to be used to influence the type of data transmission in order to achieve the highest possible data transmission rate.

The radio system described has a cell-like structure, a cell Z being shown schematically in FIG. At the center of cell Z is a base station BS, which corresponds to the network side of the radio system. Furthermore, the base station BS corresponds to the first subscriber mentioned in the claims.

In addition, there are a plurality of mobile stations MS in cell Z, each of which corresponds to the two- correspond to ten participants. Between the base station BS and the mobile stations MS various data with the transmission direction from the base station BS to a mobile station MS as a downlink direction is referred to, and refers to the transmission from a mobile station MS to the base station BS as an uplink direction will carry digitally ^¬. Zvi be ^¬ rule the base station BS and a mobile station MS voice data, for example, gene as part of a telephone conversation übertra ^¬, transmitted in the uplink direction or in the downlink direction amounts of data per unit time are substantially equal. In addition, the radio system also offers services in which significantly higher amounts of data are transmitted in the downlink direction, for example for the transmission of a radio or television program. In the present example, such data are transmitted in the form of packet data PD.

During the data transmission, the data is modulated and encoded, both different code rates and different modulations being used. The code rates 1/4, 1/2 and 3/4 as well as the modulations 4, 8, 16, 64 are used. Phase modulation and quadrature amplitude modulation are used as the modulation method. In order to achieve a high data transmission rate when transmitting the packet data PD, both high code rates and high modulation are used in the radio system, in which case the susceptibility to interference is increased. In order to nevertheless achieve reliable data transmission, the interference in the data transmission is measured by the mobile stations MS and transmitted back to the base station BS, which adapts the coding and modulation so that the highest possible data transmission rate is always achieved. As shown in FIG. 3, the measurement results are sent back to the base station BS within a report message BN by the mobile stations MS. At least two different formats are provided in the radio system for the control messages SN and the report messages BN. De basic structure of a control message and a report message SN BN is as follows, wherein for the JE information element specified in addition whether it is zwin ^¬ quietly required or optional.

Information element Art

Message type mandatory RRC transaction identifier mandatory

Integrity control information optional

Measurement mode optional

Measurement identification mandatory

Measurement control mandatory Measurement report mode optional

Additional measurement list optional

Measurement type mandatory DPCH compression mode Status information optional

In the control message SN described above, the abbreviation RRC stands for radio resource control and the abbreviation DPCH for special physical channel.

The structure of a report message BN is shown below, with the type of each information element being specified.

Information element Art

Measurement type mandatory Integrity control information optional

Measurement mode optional

Measurement identification mandatory

Mandatory measurement results

Measurement results for RÄCH optional Additional measurement results optional

Event results optional The abbreviation RÄCH stands for random access channel.

Both in the control message SN as Judges in the Berichtnach- BN field is measurement mode in which the format ^¬ information is transmitted. In the present example only two formats are provided, one of which USAGE in the transmission of packet data with a high transmission rate ^¬ is det. Since only two formats can be distinguished, 1 bit is sufficient for this information element.

The format for the control message SN for packet data transmission with a high data transmission rate is specified below. The number of data bits is also specified for each information element.

Information element number of bits

Measurement type 2

Measurement mode 1 measurement identification 4

Measuring control 2

Measurement report mode 1

Measurement type 7

The format of the report message BN is now given below for the case of packet data transmission with a high data transmission rate, the number of bits for each information element likewise being specified.

Information element number of bits

Measurement type 2

Measuring mode 1

Measurement identification 4

Measurement results 10

Both the control message SN and the report message BN each have a total of 17 bits. The data transmission in the radio system is a structure of the frame 1 based on the un in each 15 time slots 2 are tert ^¬ approaches. The structure of such a frame 1 and of a time slot 2 extracted therefrom is shown in FIG. A frame 1 lasts for 10 milliseconds.

Data in different data fields are transmitted within a time slot 2. In addition to data fields which are not shown, a data field 3 is provided in the time slot 2 shown, in which the control message SN or the report message BN is transmitted. The length of this data field 3 is dimensioned such that a maximum of 17 bits can be transmitted in a time frame 1. The control message SN or the report message BN according to the format selected for the packet data transmission can therefore be transmitted in time slots 2 within a time frame.

The second format for the control message SN and the report message BN is used for all other data transmissions in which such a high data transmission rate is not required. According to this second format, the control message SN and the report message BN contain further information elements and can have a total of up to 136 bits. In this case, it is generally not possible to transmit a control message SN or a report message BN within a time frame 1, but rather to be divided into several time frames 1. The result of this is that the measurement results are only available to the base station BS after several 10 milliseconds and the base station BS can accordingly react more slowly to changes in the transmission quality.

Claims

claims

1. Method for operating a radio system in which data can be transmitted between participants (BS, MS), in which method

a first subscriber (BS) transmits a control message (SN) to a second subscriber (MS),

- The second subscriber (MS), depending on the control message (SN), carries out measurements relating to the data transmission in the radio system and

the second participant (MS) transmits a report message (BN) with results of the measurement to the first participant (BS),

wherein at least two formats can be selected for the control message (SN) and / or the report message (BN) and format information is transmitted in the radio system, indicating the format in which the control message (SN) or the report message (BN) is transmitted.

2. The method according to claim 1, that the format information is transmitted in a control message (SN) or in a report message (BN).

3. The method according to any one of the preceding claims, that the control message (SN) or the report message (BN) has a different length depending on the format.

4. The method according to any one of the preceding claims, characterized in that the format for the control message (SN) or the report message (BN) as a function of the transmission rate for the data transmission between the first subscriber (BS) and the second subscriber (MS) is selected.

5. The method according to claim 3 and 4, characterized in that the length decreases the control message (SN) or the Berichtnach ^¬ directing (BN) of different transmission rate in dependence of the Datenübertra ^¬ selected formats with increasing Datenübertra ^¬ transmission rate.

6. The method according to any one of the preceding claims, characterized in that the control message (SN) and / or the report message (BN) and / or the format information contains information elements in the form of indicators that correspond to a list stored by the participants (BS, MS) can be assigned.

7. The method according to any one of the preceding claims, that the control message (SN) contains information about parameters of the measurements carried out by the second subscriber (MS).

8. The method according to any one of the preceding claims, that the control message (SN) contains information about a start and / or stop time of the measurements carried out by the second subscriber (MS).

9. The method according to any one of the preceding claims, characterized in that the radio system is a mobile radio system and the first subscriber (BS) corresponds to the network side of the mobile radio system and the second subscriber (MS) corresponds to a mobile station.

10. The method of claim 9, d a d u r c h g e k e n n z e i c h n e t that the radio system is a UMTS mobile radio system.

11. The method according to any one of the preceding claims, characterized in that when the data is transmitted in the form of packet data, a format is selected in which the control message (SN) or report message (BN) is shorter than in the case of a transmission of the data in Form of continuous data from ^¬ selected format.

12. The method as claimed in one of the preceding claims, that the measurements carried out by the second subscriber (MS) detect interference in the data transmission between the subscribers (BS, MS).

13. The method as claimed in claim 12, so that parameters of the data transmission are changed as a function of the results of the measurements.

14. The method according to claim 13, so that the parameters of the radio transmission are changed in such a way that the data transmission rate decreases as the measured data transmission disturbances increase.

15. The method according to claim 13 or 14, characterized in that the data for the transmission are modulated and coded, wherein with increasing measured interference of the data transmission, a lower modulation and / or less coding and with decreasing measured interference of the data transmission, a higher type of modulation and / or higher coding is selected.

16. The method according to claim 15, and that the modulation type is a quadrature phase modulation, an 8-phase modulation, a 16-quadrature

Amplitude modulation or a 64-quadrature amplitude modulation can be.

17. The method according to claim 15 or 16, d a d u r c h g e k e n n z e i c h n e t that the coding type can have the code rate 1/4, 1/2 or 3/4.

18. The method according to any one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that the energy received per unit time is measured divided by the power density in the frequency band.

19. The method according to any one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that the data are code-modulated during data transmission and the signal power received for a code is measured.

20. The method according to any one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that the strength of a received carrier frequency is measured.

21. The method according to any one of the preceding claims, that the data are transmitted in a time slot structure and the interference to a received signal is measured in a specific time slot.

22. The method according to any one of the preceding claims, characterized in that the data is code-modulated during transmission and transmitted in time slots and the signal power received for a code in a time slot is measured.

23. The method according to any one of the preceding claims, that the data are transmitted in a time frame structure and the control message (SN) and / or the report message (BN) of at least one specific format are transmitted completely in a time frame (1).

24. The method according to any one of claims 1 to 22, that the data are transmitted in a time frame structure and the control message (SN) and / or the report message

(BN) at least one specific format can be transmitted over several time frames (1).

25. Radio system for transmitting data between participants (BS, MS) with a first participant (BS) and a second

Participant (MS),

the first subscriber (BS) being set up in such a way that it transmits a control message (SN) to the second subscriber (MS), and

the second subscriber (MS) is set up in such a way that, depending on the control message (SN), it carries out measurements relating to the data transmission and transmits a report message (BN) with results of the measurements to the first subscriber (BS),

wherein the radio system is set up in such a way that at least two formats are provided for the control message (SN) and / or the report message (BN) and format information is transmitted in the radio system which indicates the format there, in which the control message (SN) or the report message (BN) is transmitted.

26. Radio system according to claim 25, so that the radio system is set up to carry out the method according to one of claims 1 to 24.

27. Transmitter for transmitting data in a radio system, the transmitter being set up such that it transmits a control message (SN) to a second subscriber (MS) of the radio system, at least two formats for the control message (SN) are provided and the transmitter (BS) transmits format information that indicates the format in which the control message (SN) is transmitted.

28. Transmitter according to claim 27, so that the transmitter is set up to carry out the method according to one of claims 1 to 24.

29. Receiver for receiving data in a radio system, the receiver (MS) being set up in such a way that it carries out measurements relating to data transmission in a radio system as a function of a control message (SN) received from a first subscriber (BS) of the radio system and a report message (BN) with results of the measurements is transmitted to the first subscriber (BS), at least two formats being provided for the report message (BN) and the receiver (MS) transmitting format information indicating the format in which the report message is (BN) is transmitted.

30. Receiver according to claim 29, so that the receiver is set up to carry out the method according to one of claims 1 to 24.