WO2005036772A2

WO2005036772A2 - Transceiver using diversity and frequency hopping

Info

Publication number: WO2005036772A2
Application number: PCT/IB2004/051988
Authority: WO
Inventors: Thomas Weiser
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2003-10-08
Filing date: 2004-10-06
Publication date: 2005-04-21
Also published as: WO2005036772A3

Abstract

In a transmitter (2) having a first transmission stage (T1) for the wireless transmission of a first information item (S1) via a first transmission channel (K11, K12) and having at least one second transmission stage (T2) for the wireless transmission of at least one second information item (S2), associated with the first information item (S1), via at least one second transmission channel (K2 1, K22) and having a channel selection stage (5) which is designed to generate a first channel selection information item (KW 1) and at least one second channel selection information item (KW2), the first channel selection information item (KW 1) can be fed to the first transmission stage (TI) and the first channel selection information item (KW1) defines the first transmission channel (K11, K12) and the at least one second channel selection information item (KW2) can be fed to the at least one second transmission stage (T2) and the at least one second channel selection information item (KW2) defines the at least one second transmission channel (K2 1, K22), wherein the first transmission channel differs from the at least one second transmission channel.

Description

Transceiving device for transmitting at least one information item

The invention relates to a transmitter having a first transmission stage for the transmission of a first information item via a first transmission channel and having at least one second transmission stage for the transmission of at least one second information item, associated with the first information item, via at least one second transmission channel. The invention furthermore relates to a receiver having a first reception stage for receiving a first information item via a first transmission channel and having at least one second reception stage for receiving at least one second information item, associated with the first information item, via at least one second transmission channel. The invention furthermore relates to an information transmission system having a transmitter of the type mentioned in the first paragraph and having a receiver of the type mentioned in the second paragraph. The invention furthermore relates to a transmission method, in which transmission method a wireless transmission of a first information item via a first transmission channel and a wireless transmission of at least one second information item, associated with the first information item, via at least one second transmission channel is carried out. The invention furthermore relates to a reception method, in which reception method reception of a first information item that has been wirelessly transmitted via a first transmission channel and reception of at least one second information item, that has been wirelessly transmitted via at least one second transmission channel and is associated with the first information item, is carried out.

A method and a device for the wireless transmission of information items are known from the document US 6,061,574. In said document, a controller controls at least two transmitters, which are spatially remote from one another, so that an identical information item is transmitted via these transmitters at the same time. This transmission principle is known to persons skilled in the art as so-called "simulcast" and is used to transmit an important information item. One disadvantage of this is the high redundancy of this system, since there has to be at least twice as many transmitters and additional control means are required in order to simultaneously control the transmitters, which are usually very far apart. Furthermore, in the case of "simulcast" transmission, interference problems arise at the receivers, said problems mainly being caused by different signal propagation times of the signal emitted by the individual transmitters. These interference problems are mentioned in more detail in said document US 6,061,574.

It is an object of the invention to provide a transmitter of the type mentioned in the first paragraph and a receiver of the type mentioned in the second paragraph and an information transmission system of the type mentioned in the third paragraph and a transmission method of the type mentioned in the fourth paragraph and a reception method of the type mentioned in the fifth paragraph, wherein the abovementioned disadvantages are avoided. In order to achieve the abovementioned object, features according to the invention are provided in a transmitter according to the invention so that a transmitter according to the invention can be characterized as follows, namely: a transmitter having a first transmission stage for the wireless transmission of a first information item via a first transmission channel and having at least one second transmission stage for the wireless transmission of at least one second information item, associated with the first information item, via at least one second transmission channel and having channel selection means which are designed to generate a first channel selection information item and at least one second channel selection information item, which first channel selection information item can be fed to the first transmission stage and defines the first transmission channel and which at least one second channel selection information item can be fed to the at least one second transmission stage and defines the at least one second transmission channel, which differs from the first transmission channel. In order to achieve the abovementioned object, features according to the invention are provided in a receiver according to the invention so that a receiver according to the invention can be characterized as follows, namely: a receiver having a first reception stage for receiving a first information item that has been wirelessly transmitted via a first transmission channel and having at least one second reception stage for receiving at least one second information item, associated with the first information item, that has been wirelessly transmitted via at least one second transmission channel and having fault detection and correction means for detecting transmission faults in at least one of the received first information item and the received at least one second information item and for correcting a detected faulty information item using the at least one information item associated with the faulty information item. In order to achieve the abovementioned object, a transmitter according to the invention and a receiver according to the invention are provided in an information transmission system according to the invention. In order to achieve the abovementioned object, features according to the invention are provided in a transmission method according to the invention so that a transmission method according to the invention can be characterized as follows, namely: a transmission method, in which transmission method a wireless transmission of a first information item via a first transmission channel and a wireless transmission of at least one second information item, associated with the first information item, via at least one second transmission channel is carried out, and wherein a first channel selection information item and at least one second channel selection information item are generated, and wherein the first transmission channel is defined by means of the first channel selection information item and wherein the at least one second transmission channel, which differs from the first transmission channel, is defined by means of the at least one second channel selection information item. In order to achieve the abovementioned object, features according to the invention are provided in a reception method according to the invention so that a reception method according to the invention can be characterized as follows, namely: a reception method, in which reception method reception of a first information item wirelessly that has been transmitted via a first transmission channel is carried out and reception of at least one second information item, that has been wirelessly transmitted via at least one second transmission channel and is associated with the first information item, is carried out, and detection of transmission faults in the received first information item and correction of a detected faulty first information item is carried out using the at least one other associated information item. By providing the features according to the invention, a much lower outlay on apparatus is required compared to information transmission by means of "simulcast". In particular, according to the invention it is not necessary for the at least two transmission stages to be arranged spatially remote from one another. On the other hand, by virtue of the measures according to the invention a high reliability of the information transmission against faults is achieved on account of the simultaneous transmission of information via different transmission channels. This has a positive effect in particular when transmitting information in "free" mode, that is to say frequency bands which are not controlled by official regulations, where account often has to be taken of the fact that a selected transmission channel is also used by other systems at the same time. Since the first information item and the second information item are transmitted on different transmission channels, the problem of interference at the receiver is also solved. The transmission of a first information item and at least one second information item associated therewith furthermore offers the advantage that the associated other information item can be used to correct transmission faults in one of the two information items. According to the additional measures of claims 2, 11, 19 and 28, the advantage of further increased fault reliability is provided. As a result of the fact that at least one transmission stage transmits the information item via changing transmission channels, the probability that the information will at least for the most part be transmitted via non-faulty transmission channels is increased, as a result of which a higher data throughput can be achieved. This is particularly important in the case of so-called "streaming content" such as, for example, in the case of the continuous transmission of audio and/or video signals, where fault correction measures can only be taken to a limited extend on account of the high amount of data that is continuously appearing. In the case of such "streaming content", it is generally also not possible, or possible only to a very limited extent, to request that data packets which have not arrived or have arrived only in mutilated form at the receiver on account of a faulty transmission channel be resent, since this would interrupt the data stream. In particular, the human ear reacts very sensitively to interruptions in the playback of an audio data stream. In order to alleviate this problem, it has already been proposed in the past to buffer-store the data reaching the receiver in a memory, although only short signal interruptions can be compensated in this way. If the transmission means changes the transmission channels in a time-controlled manner, the time interval between the transmission channel changes should be small in order that faulty transmission channels are left quickly and measures taken at the receiver end, such as buffer-storage, can become effective. It may be mentioned that the switching of transmission channels is also known by the term "channel hopping" from HF transmission technology and is used for example in wireless Bluetooth transmission technology. In the known applications, however, only a single transmission means is used which at all times transmits information only via a single transmission channel, so that only a single information item can be transmitted and not - as proposed according to the invention - at least two information items that are associated with one another. According to the additional measures of claims 3 and 20, the advantage is obtained that even if contact with the transmitter side is interrupted at the receiver side on account of a faulty transmission channel, the receiver is nevertheless able to predict and carry out the next transmission channel change. According to the additional measures of claims 4, 12, 21 and 29, the advantage is obtained that there is no need for a separate transmission channel for transmitting control signals to the receiver. According to the additional measures of claims 5 and 22, the advantage is obtained that successful information transmission is possible even in the presence of broadband interference sources. As an example of such a broadband interference source, mention may be made of a Wireless Local Area Network which operates in the free 2.4 GHz frequency band and takes up approximately one third of the available bandwidth. On account of the measures according to the invention, there is a high probability that, if a transmission channel used by a transmission stage is interfered with by the WLAN, the next transmission channel selected by the transmission stage will be free of interference. According to the additional measures of claims 6 and 23, the effect of broadband interference sources on information transmission is largely eliminated, since it is to be assumed that either the first information item or the second information item associated therewith is transmitted via a transmission channel which does not lie in the frequency band of the broadband interference source. According to the additional measures of claims 7 and 24, the probability that transmission faults will occur is further reduced in that use is made more rarely of transmission channels which have recently been recognized as faulty. It is useful, however, to occasionally select these transmission channels since a fault that existed may have disappeared. If the fault continues to exist, the time until the next new selection of this transmission channel can successively be increased. According to the additional measures of claims 8 and 25, the advantage is obtained that the reconstruction at the receiver end of information blighted by transmission faults is made easier. Given a suitable fault checking information item, the available bandwidth can be optimally used since the redundancy in the transmitted information items is low. According to the additional measures of claims 9, 16, 26 and 32, the advantage is obtained of easier reconstruction at the receiver end of information blighted by transmission faults. According to the additional measures of claims 13 and 30, the advantage is obtained that the transmitter receives information about the quality of the transmission channels used and can take suitable measures to rarely or never select relatively poor-quality transmission channels. According to the additional measures of claims 14 and 31, the advantage is obtained that the fault detection signal is successfully transmitted to the transmitter by the receiver since it is ensured that the fault detection signal is not transmitted via the transmission channel that has been recognized as faulty. According to the additional measures of claim 15, the advantage is obtained that no separate transmission channel is taken up by the transmission of the fault detection signal. The abovementioned aspects and further aspects of the invention emerge from the example of embodiment described below and are explained with reference to this example of embodiment.

The invention will be further described with reference to an example of embodiment shown in the drawings to which, however, the invention is not restricted. Fig. 1 shows an information transmission system according to the invention in the form of a block diagram. Fig. 2 shows an example of the structure of a data frame that is to be used in the information transmission system according to the invention.

Fig. 1 shows an information transmission system 1 according to the invention. The information transmission system 1 comprises a transmitter 2 for the wireless transmission of information items and a receiver 3 for receiving information items. More specifically, the transmitter 2 is designed to wirelessly transmit a first information item SI and a second information item S2, associated with this first information item SI, via a transmission path, wherein use is made of a large number of transmission channels Kl 1, K12 to Kin and K21, K22 to K2m in a predefined frequency band, for example the freely usable 2.4 GHz band. For this purpose, the transmitter 2 comprises information processing means 4 for processing the first information item SI and the second information item S2 associated therewith. The first information item SI and the second information item S2 may be for example the left and right channel of a stereo audio signal which is transmitted continuously as a data stream to the receiver 3 and is forwarded by the latter to signal processing means 8 which are designed as an audio signal playback unit. An alternative possibility of encoding such a stereo audio signal into the two information items SI, S2 consists in transmitting the mono component as the first information item SI and the stereo component as the second information item S2. Another example of the information items that are to be transmitted are the individual components of a video signal. It may be mentioned that there may be associated with the first information item not just a single second information item but rather also more than one second information item, that is to say a second information item and a third information item and a fourth information item. The first information item SI generated by the information processing means 4 is fed to a first transmission stage TI which is designed for the wireless transmission of the first information item SI via a transmission channel Kl 1, K12. The second information item S2 generated by the information processing means 4 is fed to a second transmission stage T2 which is designed for the wireless transmission of the second information item S2 via a transmission channel K21, K22. The transmission channels can be selected from a number of possible transmission channels within a predefined frequency band. For this purpose, the transmitter 2 comprises channel selection means 5 which are designed to generate a first channel selection information item KWl and at least one second channel selection information item KW2. The first channel selection information item KWl is fed to the first transmission stage TI and defines for this first transmission stage TI the transmission channel Kli that is to be selected, for example the channel Kl 1. The second channel selection information item KW2 is fed to the second transmission stage T2 and defines for this second transmission stage T2 the transmission channel K2j that is to be selected, for example the channel K21. As an alternative to the respective definition of individual transmission channels by means of the relevant channel selection information items KWl, KW2, the channel selection means 5 may also be designed to generate channel selection information items KWl and KW2 which contain an order of a number of transmission channels Kli and K2j which are to be selected by the respective transmission stage TI or T2 either at defined time intervals or as a function of operating parameters, such as the quality of individual transmission channels Kli or K2j. It may be mentioned at this point that a so- called adaptive "channel hopping" is known in the prior art for a single channel as a function of the transmission quality. By contrast, in the present case the channel selection means 5 are designed to deal with two channels in a coordinated manner and also such that the channel selection information item KWl and KW2 generated by them ensures that at no time do the transmission stages T 1 and T2 use the same transmission channel. It may be mentioned that although in the case described here only two associated information items SI and S2 are generated and transmitted by the respective transmission stage TI and T2, the invention is not restricted thereto; rather, any desired number of associated information items SI can be generated and transmitted by means of a corresponding number of transmission stages Ti. The channel selection means 5 are advantageously designed such that for each transmission stage TI or T2 not just one transmission channel Kl 1 or K12 is defined but rather the transmission channels Kl 1, K12 ... Kin or K21, K22 ... K2n defined for each transmission stage are switched at short time intervals, and this corresponds per se to the "channel hopping" known from HF transmission technology, although in the present case the abovementioned operating conditions are advantageously taken into account, such as the quality of individual transmission channels Kij for example. The time intervals between switching the transmission channels Kli and K2j are to be selected to be suitably short so that even in the event of total loss of part of an information item during transmission via a completely faulty transmission channel Kl i or K2j it is ensured that the faulty or not received, part of the information item can be corrected or approximately reconstructed in the receiver 3 while maintaining a necessary minimum speed or minimum data rate of the data stream. In order to make the information transmission system 1 more robust against broadband interference sources such as, for example, a WLAN in the 2.4 GHz frequency band, the channel selection means 5 are designed such that the transmission stages TI or T2 controlled by them by means of the channel selection information item KWl or KW2 in each case use those transmission channels Kli or K2j which are at a distance of at least one third of the available frequency range from the transmission channel being used at the same time by the other transmission stage. In addition or as an alternative to this, the channel selection means 5 may control the transmission stage TI and T2 such that when switching from one transmission channel to the other transmission channel the new transmission channel has a distance, in terms of its frequency, of at least one third of the available frequency range from the previous transmission channel. One essential aspect of the present invention is that the information items SI and S2 that are to be transmitted are checked for transmission faults in the receiver in as simple a manner as possible and with a low hardware and software outlay, and it may also be possible for these faults to be corrected without falling below a predefined minimum data transmission rate. For this purpose, the information processing means 4 are designed such that redundant information is added to the actual information. This redundant information may on the one hand comprise a defined order of transmission channels Kij that are to be used next, optionally supplemented with a time reference, so that the receiver 3 can switch to the next transmission channel or channels Kij in synchronization with the transmitter 2 even in the case of a major fault of a transmission channel Kij. The redundant information may also comprise fault checking and/or fault correction information, such as checksums for example. In a further refinement of the invention, the information processing means 4 are designed such that they supplement the first information item SI with at least part S2-RED of the second information item S2, as shown in the data packet in Fig. 2, which additionally comprises an order of transmission channels to be used next, referred to in general by KINFO. This order reads Kl 1, K12, K18, K16. In a similar manner, the second information item S2 is supplemented by part of the first information item SI, although this is not shown in Fig. 2. However, using modern fault detection measures, it is usually not necessary to transmit both the entire first information item SI and the entire second information item S2 via the two transmission stages TI and T2. The receiver 3 comprises a first reception stage Rl for receiving the first information item SI that has been wirelessly transmitted via a first transmission channel Kl 1, K12. It should be expressly mentioned that the received first information item SI may possibly be blighted with transmission faults. The receiver 3 furthermore comprises a second reception stage R2 for receiving the second information item S2 that has been wirelessly transmitted via a second transmission channel K21, K22. The two reception stages Rl and R2 are designed such that the transmission channel Kij, via which they receive information items, can be selected from a large number of possible channels. The selection of a respective transmission channel Kij by the two reception stages Rl and R2 is made under the control of a controller 6, which is in turn controlled by fault detection and correction means 7 which where necessary detect and - if possible - correct transmission faults contained in the received information items SI, S2, so that the original information items SI, S2 are reconstructed in full or at least for the most part and are then fed to signal processing means 8. The signal processing means 8 may be designed for example as an audio signal playback device. If transmission faults are detected in the received information item SI or S2, the fault detection and correction means 7 transmit a transmission fault signal FS to the 5 transmitter 2. In one embodiment, this transmission fault signal FS is transmitted directly to the channel selection means 5 of the transmitter 2, which can then react to it by less frequently selecting the transmission channel Kij that has been recognized as faulty. It should be mentioned in this connection that both the transmitter 2 and the receiver 3 must have transceiver functionality, so that they are designed both to transmit and to receive information 0 items, although this goes without saying for the person skilled in the art. In an alternative embodiment, both the transmission stages TI, T2 of the transmitter 2 and the reception stages Rl, R2 of the receiver 3 are designed as bidirectional transmitters/receivers, which in the technical jargon are referred to as transceivers. The transmission fault signal FS is in this case transmitted to the transmitter 2 via one, but preferably via both, reception stages Rl, R2, 5 wherein, for the purpose of increased data transmission reliability, in one preferred refinement the transmission fault signal FS is transmitted by a respective reception stage Rl or R2 to that transmission stage TI or T2 from which it usually does not receive information, that is to say with which it has no common transmission channel. In the present example of embodiment, therefore, the first reception stage Rl would transmit the signal FS to the0 second transmission stage T2 and the second reception stage R2 would transmit the signal FS to the first transmission stage TI, as shown by a dotted line between the first reception stage Rl and the second transmission stage T2 and between the second reception stage R2 and the first transmission stage TI. In order to detect transmission faults in the received information item SI ', S2',5 the fault detection and correction means 7 may in general make use of fault checking and/or fault correction information items contained in the respective associated information items SI, S2. As an alternative to this, the detection of transmission faults may take place on the basis of missing or unexpected information components, such as missing or incorrect identification codes or checksums for example.O It may be mentioned that the second transmission stage T2 may be designed to be switched on and off as a function of a frequency of faults or a rate of faults on the first transmission channel Kli, as a result of which improved energy management is obtained, something which is particularly important in the case of battery-operated devices. It may furthermore be mentioned that, in one application in which a quasi- permanent bidirectional communication or a unidirectional communication divided into time slots is required, the transmitter 2 and the receiver 3 may swap roles. It may furthermore be mentioned that the fault detection signal FS may also be transmitted in a different frequency channel or using a different transmission method from that frequency channel or transmission method used to transmit the information item SI or S2. It may furthermore be mentioned that the term wireless transmission is also to be understood as meaning transmission by means of infrared light or by means of magnetic coupling or by means of another type that is not explicitly mentioned here.

Claims

CLAIMS:

1. A transmitter having a first transmission stage (TI) for the wireless transmission of a first information item (SI) via a first transmission channel (Kl 1, K12) and having at least one second transmission stage (T2) for the wireless transmission of at least one second information item (S2), associated with the first information item (SI), via at least one second transmission channel (K21, K22) and having channel selection means (5) which are designed to generate a first channel selection information item (KWl) and at least one second channel selection information item (KW2), which first channel selection information item (KWl) can be fed to the first transmission stage (TI) and defines the first transmission channel (Kl 1, K12) and which at least one second channel selection information item (KW2) can be fed to the at least one second transmission stage (T2) and defines the at least one second transmission channel (K21, K22), which differs from the first transmission channel.

2. A transmitter (2) as claimed in claim 1, wherein at least one of the transmission stages (TI, T2) is designed as a switchable transmission stage (TI, T2) for the switchable transmission of the first information item (SI) or of the at least one second information item (S2) via one of many possible transmission channels (Kl 1, K12, K21, K22) and the channel selection information item (KWl, KW2) that can be generated by the channel selection means (5) can be fed to the at least one switchable transmission stage (TI, T2) in order to switch the transmission channel of this transmission stage (TI, T2) at specific time intervals or as a function of the quality of transmission channels.

3. A transmitter (2) as claimed in claim 2, wherein the channel selection information item (KWl, KW2) that can be generated by the channel selection means (5) defines an order (KINFO) of transmission channels (Kij) for the at least one associated switchable transmission stage (TI, T2).

4. A transmitter (2) as claimed in claim 3, wherein the at least one switchable transmission stage (TI, T2) transmits the defined order (KINFO) of transmission channels (Kij) together with the first information item (SI) that is to be transmitted or the at least one second information item (S2) that is to be transmitted, and optionally supplements this with a time reference.

5. A transmitter (2) as claimed in claim 2, wherein successive transmission channels (Kl 1, K12, K21, K22) that are defined in the at least one switchable transmission stage (TI, T2) by the relevant channel selection information item (KWl, KW2) are spaced apart from one another in terms of their frequency at least by one third of the frequency range available for all transmission channels (Kij).

6. A transmitter (2) as claimed in claim 1, wherein the first transmission channel

(Kl 1, K12) defined in the first transmission stage (TI) by the first channel selection information item (KWl) and the at least one second transmission channel (K21, K22) defined in the at least one second transmission stage (T2) by the at least one second channel selection information item (KW2) are spaced apart from one another in terms of their frequency at least by one third of the frequency range available for all transmission channels (Kij).

7. A transmitter (2) as claimed in claim 1, wherein the channel selection means

(5) are designed such that transmission channels (Kij) that have been or can be recognized as faulty are selected at greater time intervals than non-faulty transmission channels (Kij).

8. A transmitter (2) as claimed in claim 1, wherein information processing means (4) are provided which supplement the first information item (SI) and the at least one second information item (S2), associated with the first information item (SI), with a fault checking and/or fault correction information item.

9. A transmitter (2) as claimed in claim 8, wherein the information processing means (4) are designed to supplement the at least one second information item (S2) with at least part of the first information item (SI) and to supplement the first information item (SI) with at least one part (S2-RED) of the at least one second information item (S2).

10. A receiver (3) having a first reception stage (Rl) for receiving a first information item (SI) that has been wirelessly transmitted via a first transmission channel (Kl 1, K12) and having at least one second reception stage (R2) for receiving at least one second information item (S2), associated with the first information item (SI), that has been wirelessly transmitted via at least one second transmission channel (K21, K22) and having fault detection and correction means (7) for detecting transmission faults in at least one of the received first information item (SI) and the received at least one second information item (S2) and for correcting a detected faulty information item using the at least one information item associated with the faulty information item.

11. A receiver (3) as claimed in claim 10, wherein at least one reception stage (Rl, R2) is designed for the switchable reception of the first information item (SI) or of the at least one second information item (S2) via one of many possible transmission channels (Kl 1, K12, K21, K22).

12. A receiver (3) as claimed in claim 11, wherein the switchable reception stages (Rl, R2) are designed to react, during the selection of a transmission channel, to a channel selection information item (KWl, KW2) which is received by the reception stages (Rl, R2) together with the first information item (SI) or the at least one second information item (S2).

13. A receiver (3) as claimed in claim 10, wherein the fault detection and correction means (7) are designed to transmit, upon detection of an incorrectly received information item (SI, S2), a fault detection signal (FS) to a transmitter (2) from which the information item (SI, S2) was transmitted.

14. A receiver (3) as claimed in claim 13, wherein the receiver (3) is designed to transmit the fault detection signal (FS) via a different transmission channel from the transmission channel via which the faulty information item (SI, S2) was received.

15. A receiver (3) as claimed in claim 14, wherein the reception stages (Rl, R2) are designed as bidirectional transceivers and the fault detection signal (FS) is transmitted via one of the reception stages (Rl, R2), preferably via a different reception stage (R2, Rl) from the reception stage (Rl, R2) by which the faulty information item was received.

16. A receiver (3) as claimed in claim 10, wherein the fault detection and correction means (7) are designed to detect an incorrectly received first information item (SI) or an incorrectly received second information item (S2) from a fault checking and/or fault correction information item contained in the incorrectly received information item or from missing or unexpected information components, such as missing or incorrect identification codes or checksums for example.

17. An information transmission system (1) having a transmitter (2) as claimed in claims 1 to 9 and having a receiver (3) as claimed in claims 10 to 16.

18. A transmission method, in which transmission method a wireless transmission of a first information item (SI) via a first transmission channel (Kl 1, K12) and a wireless transmission of at least one second information item (S2), associated with the first information item (SI), via at least one second transmission channel (K21, K22) is carried out, and wherein a first channel selection information item (KWl) and at least one second channel selection information item (KW2) are generated, and wherein the first transmission channel (Kl 1, K12) is defined by means of the first channel selection information item (KWl) and wherein the at least one second transmission channel (K21, K22), which differs from the first transmission channel, is defined by means of the at least one second channel selection information item (KW2).

19. A transmission method as claimed in claim 18, wherein at least one of the transmission channels (Kl 1, K12, K21, K22) for transmitting the first information item (SI) or the at least one second information item (S2) is switched to another of many possible transmission channels (Kij) at specific time intervals or as a function of the quality of transmission channels, by means of the relevant channel selection information item (KWl, KW2).

20. A transmission method as claimed in claim 19, wherein the relevant channel selection information item (KWl, KW2) defines an order of transmission channels (Kij) to which switching is carried out in accordance with the order.

21. A transmission method as claimed in claim 20, wherein the defined order (KINFO) of transmission channels (Kij) is transmitted together with the first information item (SI) or second information item (S2) that is to be transmitted, this optionally being supplemented with a time reference.

22. A transmission method as claimed in claim 19, wherein successively selected transmission channels (Kl 1, K12, K21, K22) are spaced apart from one another in terms of their frequency at least by one third of the frequency range available for all transmission channels (Kij).

23. A transmission method as claimed in claim 18, wherein the first transmission channel (Kli) and the at least one second transmission channel (K2i) are selected in terms of their frequency such that they are spaced apart from one another at least by one third of the frequency range available for all transmission channels (Kij).

24. A transmission method as claimed in claim 18, wherein transmission channels (Kij) that have been or can be recognized as faulty are selected at greater time intervals than non-faulty transmission channels (Kij).

25. A transmission method as claimed in claim 18, wherein the first information item (SI) and the at least one second information item (S2) associated therewith are supplemented with a fault checking and/or fault correction information item prior to transmission.

26. A transmission method as claimed in claim 25, wherein prior to transmission the at least one second information item (S2) is supplemented with at least part of the first information item (SI) and the first information item (SI) is supplemented with at least part (S2-RED) of the at least one second information item (S2).

27. A reception method, in which reception method reception of a first information item (SI) that has been wirelessly transmitted via a first transmission channel (Kl) is carried out and reception of at least one second information item (S2), that has been wirelessly transmitted via at least one second transmission channel (K2) and is associated with the first information item (SI), is carried out, and detection of transmission faults in the received first information item (SI) and correction of a detected faulty first information item (SI) is carried out using the at least one other associated information item.

28. A reception method as claimed in claim 27, wherein at least one of the transmission channels (Kij) is selected from many possible transmission channels (Kli, K2j) to receive the first information item (SI) or the at least one second information item (S2).

29. A reception method as claimed in claim 28, wherein the selection of a transmission channel (Kij) is made in reaction to a channel selection information item (KWi, KWj) which is received together with the first information item (SI) or the at least one second information item (S2).

30. A reception method as claimed in claim 27, wherein, upon detection of an incorrectly received information item (SI, S2), a fault detection signal (FS) is transmitted to the transmitter (2) from which the information item (SI, S2) was transmitted.

31. A reception method as claimed in claim 30, wherein the fault detection signal (FS) is transmitted via a different transmission channel (Kli, K2j) from the transmission channel (Kli, K2j) via which the faulty information item (SI, S2) was received.

32. A reception method as claimed in claim 27, wherein the detection of an incorrectly received first information item (SI) or of at least one incorrectly received at least one second information item (S2) is carried out using a fault checking and/or fault correction information item contained in the incorrectly received information item (SI, S2) or on the basis of missing or unexpected information components, such as missing or incorrect identification codes or checksums for example.